COLLAPSING MECHANICAL CIRCULATORY SUPPORT DEVICE FOR TEMPORARY USE

Abstract

A temporary, removable mechanical circulatory support heart-assist device has at least two propellers or impellers. Each propeller or impeller has a number of blades arranged around an axis of rotation. The blades are configured to pump blood. The two propellers or impellers rotate in opposite directions from each other. The device can be configured to be implanted and removed with minimally invasive surgery.

Claims

1-135. (canceled)

136. A mechanical circulatory support device comprising: a pair of contra-rotating impellers comprising a first impeller and a second impeller, the pair of contra-rotating impellers configured to fold for installation; a core shaft coupled to the first impeller; a peripheral shaft coupled to the second impeller; a first motor coupled to the core shaft; a second motor coupled to the peripheral shaft, wherein the first motor and the second motor are arranged coaxially, wherein the first motor and the second motor are contra-rotating; and an hourglass-shaped cage comprising an inlet section, a central waist section, and an outlet section, wherein the central waist section has a constant diameter when installed, wherein the first impeller and the second impeller are positioned within the central waist section of the hourglass-shaped cage when installed.

137. The mechanical circulatory support device of claim 136, further comprising a shaft sheath covering the core shaft and the peripheral shaft.

138. The mechanical circulatory support device of claim 137, further comprising at least one fluid path between the shaft sheath and the peripheral shaft.

139. The mechanical circulatory support device of claim 136, further comprising at least one fluid path between the peripheral shaft and the core shaft.

140. The mechanical circulatory support device of claim 136, wherein at least one shaft comprises a high-lubricity coating.

141. The mechanical circulatory support device of claim 136, wherein at least one impeller comprises at least two blade-carrying assemblies rotated to different azimuthal orientations.

142. The mechanical circulatory support device of claim 136, further comprising an indexing arrangement holding impeller segments in azimuthal positions.

143. The mechanical circulatory support device of claim 136, further comprising a flushing fluid path between the pair of contra-rotating impellers.

144. The mechanical circulatory support device of claim 136, wherein the hourglass-shaped cage comprises a shape memory alloy.

145. The mechanical circulatory support device of claim 136, further comprising a coating with anti-thrombotic or drug-eluding properties.

146. The mechanical circulatory support device of claim 136, wherein the peripheral shaft comprises slots for a flushing fluid path.

147. The mechanical circulatory support device of claim 136, wherein at least one impeller comprises an even number of blades.

148. The mechanical circulatory support device of claim 136, wherein blades of at least one impeller partially overlap.

149. The mechanical circulatory support device of claim 136, wherein the peripheral shaft surrounds the core shaft.

150. The mechanical circulatory support device of claim 136, further comprising a shaft sheath, wherein the shaft sheath, the peripheral shaft, and the core shaft are coaxial.

151. The mechanical circulatory support device of claim 136, wherein the core shaft is coupled to a nose cone.

152. The mechanical circulatory support device of claim 136, wherein a blade folding arrangement is in relation to a rolling direction in the manufacture of nitinol sheets.

153. The mechanical circulatory support device of claim 136, wherein the first motor and the second motor are configured to be extra-corporeal.

154. The mechanical circulatory support device of claim 136, wherein the first motor and the second motor are configured to rotate at equal revolutions per minute.

155. The mechanical circulatory support device of claim 136, wherein at least one impeller comprises a diameter between 2 mm and 40 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0184] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which corresponding reference symbols indicate corresponding parts, and in which:

[0185] FIGS. 1A-1G schematically illustrate various examples of operating configurations of the MCS device.

[0186] FIGS. 2A-2C schematically illustrate operating configurations of the MCS device comprising a balloon.

[0187] FIGS. 3A-3E schematically illustrate various examples of internal features of the MCS device.

[0188] FIGS. 4A-4C schematically illustrate examples of MCS devices configured for installation in the lumen of a blood vessel.

[0189] FIGS. 5A-5C schematically illustrate examples of an MCS device comprising various motor arrangements and features to facilitate insertion.

[0190] FIGS. 6A-6B schematically illustrate operating configurations of the MCS device opening in an umbrella-like fashion.

[0191] FIGS. 7A-7D schematically illustrate operating configurations of the MCS device comprising various motor and support configurations.

[0192] FIGS. 8A-8C schematically illustrate operating configurations of the MCS device comprising a bevel gearbox for contra-rotation.

[0193] FIGS. 9A-9D schematically illustrate operating configurations of the MCS device comprising two gearboxes.

[0194] FIG. 10 schematically illustrates an operating configuration of the MCS device comprising two gearboxes.

[0195] FIGS. 11A-11B schematically illustrate operating configurations of the MCS device comprising two gearboxes.

[0196] FIG. 12 schematically illustrates an operating configuration of the MCS device comprising a lubrication path.

[0197] FIG. 13 schematically illustrates an operating configuration of the MCS device comprising spiral grooves.

[0198] FIGS. 14A-14C schematically illustrate operating configurations of the MCS device opening in an hour glass configuration.

[0199] FIGS. 15A-15B schematically illustrate operating configurations of the hour glass configuration.

[0200] FIGS. 16A-16C schematically illustrate positions of the motor.

[0201] FIGS. 17A-17D schematically illustrate stages of delivery.

[0202] FIGS. 18A-18C schematically illustrate folding and unfolding of the blades and cage sections.

[0203] FIGS. 19A-19C schematically illustrate an extra-corporeal motor and associated gearbox for the pumping head.

[0204] FIGS. 20A-20D illustrates the rotation of a peripheral shaft relative to the core shaft. FIG. 20E illustrates another embodiment of a gearbox.

[0205] FIGS. 21A-21D illustrates lubrication and/or cooling with an extra-corporeal motor.

[0206] FIGS. 22A-22C illustrate bearings.

[0207] FIGS. 23A-23B illustrate bending blades.

[0208] FIGS. 24A-24F illustrate blade deflection.

[0209] FIGS. 25A-25E illustrate blade folding.

[0210] FIGS. 26A-26F illustrate blade construction.

[0211] FIGS. 27-155 illustrate additional impeller and component concepts.

[0212] FIGS. 156A-202F illustrate additional impeller and component concepts.

DETAILED DESCRIPTION

[0213] This invention relates in some aspects to various embodiments of percutaneously implantable cardiovascular support (PICS) devices. PICS devices can include percutaneously implantable Mechanical Circulatory Support Devices (MCSD). In some embodiments, PICS may be configured for implantation in the aorta via the femoral artery. In some methods of use, PICS may be intended for implantation percutaneously. In some methods of use, PICS may be intended for implantation with minimally invasive surgery. Cardiovascular support devices can be configured for either long-term implantation or short-term (e.g., temporary) implantation. Some embodiments may be designed for early New York Heart Association (NYHA) class III CHF (before Interagency Registry for Mechanically Assisted Circulator Support (INTERMACS level 7) and more severe conditions. In some embodiments, devices may be configured for in-series implantation in the aorta. Thus, in some embodiments, the adult specification can include about a 5 L/min flow rate and from about 20 to about 40 mm Hg pressure rise, where the remaining pressure rise is given by the diseased native heart.

[0214] Some embodiments may be designed with operating conditions specifically configured for particular state of the patient, including the stage of disease. For instance, a MCS designed for late stage II or early stage III CHF may provide a lesser pressure rise, while a MCS designed for late stage III or early stage IV CHF may provide a greater pressure rise, to better supplant the failing heart. In some embodiments, devices be configured to provide a flow rate of about, at least about, or no more than about 1 L/min, 2 L/min, 3 L/min, 4 L/min, 5 L/min, 6 L/min, 7 L/min, 8 L/min, 9 L/min, 10 L/min, or any ranges including two of the foregoing values. In some embodiments, the devices be configured to provide a pressure rise of about, at least about, or no more than about 5 mm Hg, 10 mm Hg, 15 mm Hg, 20 mm Hg, 25 mm Hg, 30 mm Hg, 35 mm Hg, 40 mm Hg, 45 mm Hg, 50 mm Hg, 55 mm, Hg 60 mm Hg, 65 mm Hg, 70 mm Hg, 75 mm Hg, 80 mm Hg, 85 mm Hg, 90 mm Hg, 95 mm Hg, 100 mm Hg, 105 mm Hg, 110 mm Hg, 115 mm Hg, 120 mm Hg, 125 mm Hg, 130 mm Hg, 135 mm Hg, 140 mm Hg, 145 mm Hg, 150 mm Hg, between 20 mm Hg and 40 mm Hg, between 20 mm Hg and 50 mm Hg, or any ranges including two of the foregoing values. In some embodiments, the remaining pressure rise is given by the diseased native heart. In some embodiments, devices can be configured with operating conditions to replicate the conditions of a healthy patient. In some embodiments, the device is configured to provide a pressure rise of between about 10-40 mmHg. In some embodiment, the device is configured for a flow rate of about 2-6 L/min. In some embodiments, the device is configured for a pressure rise of about 30 mm Hg and a flow rate of about 5 L/min. In some embodiments, the device is configured for a pressure rise of about 10-60 mm Hg and a flow rate of about 0.1-8 L/min. The ranges in the foregoing paragraph can be used in combination with, for example, contra-rotation for permanent and temporary MCSD.

[0215] Some devices may be designed to be implanted in-series with the heart. As described herein, such arrangements may effectively reduce the load on the heart. Some devices may be configured to lower the resistance to blood flow. As described herein, such arrangements provide the heart increased potential for regeneration of diseased tissue. Devices may be configured to require less power, and therefore be lighter in weight and more compact. Devices may be configured to pump blood at a continuous flow. Devices may be configured to pump blood at a pulsated flow. Devices may be configured to pump blood at a flow rate advantageous to complement the pulsing heart.

[0216] Ventricular Assist Devices (VAD) are heart assist pumps that can include an inlet anastomosed to one of the four chambers of the native diseased heart. In some methods of use, the VAD device is anastomosed to the left ventricle. This configuration is more common. In some methods of use, the VAD device is anastomosed to the right ventricle. In some methods of use, the VAD device is anastomosed to one of the atria. In some embodiments, a mechanical circulatory support heart-assist device is provided where the pump comprises impellers rotating in opposite directions. In some embodiments, the inlet to the pump is configured to be anastomosed to a chamber of the heart, and the outlet of the pump is configured to be anastomosed to the vascular system.

[0217] Mechanical circulatory support devices (MCSD) are also heart assist pumps. MCSDs, in contrast to VADs, are typically installed in the vasculature. MCSDs, in contrast to VADs, are not typically attached to any part of the diseased native heart. Usually the MCSDs are designed for a less invasive implantation procedure than the VADs.

[0218] Permanent MCSDs are devices that may be used over a short or over a long period of time. Due to their design, permanent MCSDs have some components that once installed in the human body, these components are configured to stay in the patient's body, even if some other parts of the MCSD are later removed. In some embodiments, a cage or support structure stays within the body after removal of other components. In some embodiments, a motor or power source stays within the body after removal of other components. In some embodiments, one or more components is permanently coupled to a structure within the body of the patient.

[0219] Temporary MCSDs can be specifically configured for short-term use with the intent that after the temporary use all components of the device will be fully removed from the patient's body. Thus a key characteristic of a temporary MCSD in some embodiments is that no part of the device will stay in the patient's body after use. In some embodiments, the Temporary MCSD is configured to be removed as a unit. In some embodiments, two or more components of the Temporary MCSD are configured to be removed separately or independently. In some methods of use, the Temporary MCSD is removed in a single surgical procedure. In some methods of use, the Temporary MCSD may be configured for removal via the femoral artery. In some methods of use, the Temporary MCSD may be configured for removal percutaneously. In some methods of use, the Temporary MCSD may be configured for removal with minimally invasive surgery. In some cases, temporary devices may be referred to as pVADs (percutaneous VADs).

[0220] Some devices indicated for at least class III CHF (INTERMACS levels 5, 6, 7) may be designed with the rotor of the turbomachine and electric motor being designed for implantation, periodic removal and re-implantation. In some methods of use, the devices may be configured for periodic removal via the femoral artery. In some methods of use, the devices may be configured for periodic removal percutaneously. In some methods of use, the devices may be configured for periodic removal with minimally invasive surgery. In some methods of use, the devices may be configured for re-implantation via the femoral artery. In some methods of use, the devices may be configured for re-implantation percutaneously. In some methods of use, the devices may be configured for re-implantation with minimally invasive surgery. In some methods of use, the devices can be implanted and re-implanted via the same type of procedure. In some methods of use, the devices can be implanted and re-implanted via different types of procedures. As an example, the devices may be configured for implantation, periodic removal and re-implantation via the femoral artery in the aorta.

[0221] As described herein, devices may be Permanent MCSDs such that one or more components are permanently installed. In some embodiments, the stator of the motor may be permanently installed. In some methods of use, the stator of the motor may be permanently installed around and outside the aorta, surrounding the location of the rotor. In some methods of use, the stator may be configured to be positioned around an outer circumference of the blood vessel. In some methods of use, the stator may be configured to be positioned around another structure of the patient. The stator may include a hinge or other mechanical feature to allow the stator to be positioned there around. The stator may include an anchoring structure to permanently attach to the patient. As described herein, the stator can include one or more electromagnets positioned around the circumference of the stator. The stator is configured to be positioned concentrically around the blades of a propeller or impeller to electromagnetically drive rotation of the at least one magnetic blade.

[0222] However, other components may be removed after use, or intermediately removed during use. As one example, the rotor of the turbomachine and/or electric motor may be designed to be removed. In some embodiments, all components of some devices are configured to be permanently installed.

[0223] Some devices with the above flow rate and pressure rise specifications may be configured for short term use. In some embodiments, the device is configured to be used for a few hours, e.g., about, at least about, or no more than about 1 hour, 2 hours, 4 hours, 8 hours, 12 hours, 16 hours, 20 hours, 24 hours, or a few days, e.g., 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, or any range including any two of the foregoing values. In some embodiments, the device is configured to be used less than a week, less than 5 days, less than 3 days, less than 1 day, less than 12 hours, more than 1 hour, more than 4 hours, more than 12 hours, more than 1 day, more than 3 days, more than 5 days, or any range of the foregoing values. In some embodiments, the device is configured to be used between a few hours and up to about 5 days. Devices may be configured for implantation and then complete removal of all components from the human body. Devices may be configured to address Acute Cardiogenic Shock (CGS). Devices may be configured to address Percutaneous Coronary Intervention (PCI). Devices may be configured to address acute decompensated heart failure (ADHF). Devices may be configured to address Cardio Renal Syndrome (CRS). Devices may be configured to provide temporary relief of the native heart in early or late stages of congestive heart failure. Other uses of the devices are contemplated.

[0224] Some embodiments include percutaneously implantable Temporary MCSDs configured for implantation. In some methods of use, the device may be configured for implantation in the aorta via the femoral artery. In some methods of use, the device may be configured for implantation in the aorta percutaneously. In some methods of use, the device may be configured for implantation in the aorta with minimally invasive surgery. The device may be intended for short term, temporary use, ranging from a few hours to up to about five days. At the end of use, all components of the device are removed from the patient's body.

[0225] In some embodiments, a device could include axial, and/or centrifugal impellers. Some devices may be configured to provide support during Percutaneous Coronary Intervention (PCI), including high risk PCI for those who are hemodynamically unstable after acute heart attack, for acute decompensated heart failure (ADHF), for cardio-renal syndrome (CRS) patients and acute cardiogenic shock (ACS), as well as for early NYHA class II CHF (before INTERMACS level 7) and more-severe conditions. In some embodiments, the Temporary MCSD devices described herein can be designed in series. Some devices may be configured for in-series implantation in the aorta.

[0226] Some devices can be a temporary MCSD as described herein. Devices can provide any flow rate and pressure rise described herein. However, some devices may be configured for short term use, typically varying between a few hours and up to about 5 days. All components of temporary devices can be configured to be removed after the short term use. For instance, in some embodiments, no component is configured to be permanently attached to the body of the patient. Unlike some permanently implantable devices, temporary MCSDs can be configured for implantation and then complete removal of all components from the human body. In this way, temporary devices may be configured to addresses PCI, ADHF, CRS, ACS, and temporary relief of the native heart in very early stages of CHF.

[0227] Clinical experience performed by an inventor suggests that a device with the specifications as disclosed elsewhere herein can be used effectively as an alternative to other percutaneous systems during percutaneous coronary intervention (PCI). Clinical experience performed by an inventor also suggests that the implantation location of the device (e.g., in the descending aorta) can also provide additional but substantial therapeutic advantages due to increasing perfusion to the kidneys. Other clinical advantages are contemplated.

[0228] Some illustrations of devices are included in FIGS. 1A-13. In some embodiments, features described as related to temporary devices may be incorporated into permanently implantable devices and features described as related to permanently implantable devices may be incorporated into temporary devices. Temporary devices may include any feature of any device described herein. Permanent devices may include any feature of any device described herein.

[0229] Mechanical circulatory support devices (MCSD) can include a pumping head. In some embodiments, the pumping head comprises two impellers rotating in opposite directions (contra-rotation). In some embodiments, the pumping head comprises two or impellers, with at least two impellers rotating in opposite directions. The impellers can be foldable or collapsible during insertion. In some embodiments, the contra-rotating impellers have equal rpm and opposite rotation. In some embodiments, the contra-rotating impellers have unequal rpm and opposite rotation. The impellers and surrounding support structure, if utilized, are placed in the folded position. The MCS device can be inserted via a catheter in the aorta upstream of the kidneys. This may be in the descending aorta, as shown in the figures, or further upstream in the aorta, anywhere up to the aortic valve. Once the catheter is removed, the blades and surrounding support structure spring into the unfolded position. After use, the pumping head may be removed via the reverse procedure by folding it and capturing it into a catheter.

[0230] The pumping head may be connected to one or more motors. The motor may have its own internal speed-reducing gearbox. The motor may be integrally connected to the pumping head intra-corporeally. The motor may be connected via a short bending shaft to the pumping head intra-corporeally. In some embodiments, in these intra-corporeal configurations, power may be delivered to the motor via an electric cable. In some embodiments, the electric cable may also transmit control signals from the device to outside the body or vice versa. In some embodiments, the electric cable may also transmit measured data from the device to outside the body. In some embodiments, a biocompatible lubricant may be pumped from outside the body to the intra-corporeal motor and/or gearbox or gearboxes.

[0231] In some embodiments, the device may include gearboxes and an intra-corporeal motor. In some embodiments, one shaft extending out of the intra-corporeal motor or gearmotor drives two epicyclic gearboxes in series, which achieves output contra-rotation. In some embodiments, one gearbox of the same type as the gearbox described herein with the extra-corporeal motor, can also be used.

[0232] In some embodiments, the device may include an extra-corporeal motor. In some embodiments, the impellers and gearbox achieving contra-rotation are placed intra-corporeally in the descending aorta, and they are connected to an extra-corporeal motor or gearmotor via a flexible drive shaft. The flexible drive shaft may be encased in a non-rotating sleeve. In some embodiments, a biocompatible lubricant may be pumped from outside the body to the internal components via the gap between the flexible drive shaft and the sleeve.

[0233] In some embodiments, the device may include a gearbox and an extra-corporeal motor. With an extra-corporeal motor, rotation of the two impellers in opposite directions is achieved via a gearbox, described herein. This gearbox may be just upstream of the impellers, just downstream of the impellers, or between the impellers. The gearbox receives input power and rotation from one shaft, and provides output via two contra-rotating shafts to the two impellers as described herein.

[0234] In some embodiments, the device may include blades. In some embodiments, the device may include blades that fold. In some embodiments, the impellers are four-bladed, but any number from 2 to 32 blades or more may be used in each impeller. In some embodiments, the blades have a flexible section near their hub to allow bending or folding upstream. In some embodiments, the blades have a flexible section near their hub to allow bending or folding downstream. In some embodiments, the blades bend or fold to place the blades in the catheter, as described herein. In some embodiments, the blades are folded upstream via mechanical activation. In some embodiments, the blades are folded downstream via mechanical activation. Several mechanical activation mechanisms can be employed. In some embodiments, mechanical activation is via a runner-stretcher mechanism like umbrellas. In some embodiments, mechanical activation is via a screw/gear activation mechanism like foldable marine propellers. Examples of all folding mechanisms are described herein. The blades can be foldable by any mechanical means. The blades based can be coupled to the hub via a foldable mechanism. The foldable mechanism can include a worm gear. The foldable mechanism a screw. The foldable mechanism can include a rack and pinion. The foldable mechanism can include one or more gears. The foldable mechanism can include an axle. The foldable mechanism can include a pin. The foldable mechanism can be actuated. The foldable mechanism can be self-expandable. The foldable mechanism can include a shape memory material. The foldable mechanism can include a springy or biased material. The foldable mechanism can allow the blades to be expanded. The foldable mechanism can allow the blades to be compressed.

[0235] In some embodiments, devices may include two or more foldable impellers or propellers rotating in opposite directions, e.g., contra-rotation with respect to each other. In some embodiments, contra-rotating blades rotate with equal and opposite rpm. In some embodiments, contra-rotating blades rotate with unequal rpm. The impellers, and surrounding support, are placed in the folded position via a catheter in the aorta upstream of the kidneys. In some methods of use, this may be in the descending aorta, or further upstream in the aorta, anywhere up to the aortic valve. Once the catheter is removed the blades and surrounding support spring into the unfolded position. In some methods of use, the temporary device is removed via the reverse procedure by folding it and capturing it into a catheter.

[0236] Some devices may be connected to a motor, which may have its own internal speed-reducing gearbox. The motor may be integrally connected to the devices intra-corporeally, or connected via a short bending shaft to the devices intra-corporeally. In some embodiments, a downstream gearbox can be included. The downstream gearbox can be intracorporeal. The downstream gearbox can be extra-corporeal. In some embodiments, power will be delivered to the motor via an electric cable. In some embodiments, the impellers and gearbox achieving contra-rotation are placed intra-corporeally in the descending aorta, and they are connected to an extra-corporeal motor or gear motor via a flexible drive shaft. The contra-rotating blades may have unequal rpm or equal rpm, based in part on the associated gearboxes. The electric motor may have integral with it an epicyclic gearbox reducing motor rpm the first time, e.g., a gear motor, then additional gearboxes reduce the motor rpm a second time before the impellers. In some embodiments, rotation of the two impellers in opposite directions is achieved via a gearbox. This gearbox may be just upstream of the impellers, just downstream of the impellers, or between the impellers. The gearbox receives input power and rotation from one shaft, and provides output via one or more two contra-rotating shafts to the two impellers. In some embodiments, the impellers are actuated purely mechanically, and not via any internal or external magnetic elements.

[0237] In some embodiments, a gearbox can be an epicyclic gearbox, some variants of which are used in mechanical watches, but for the first time in heart-assist pumps, to the inventors' knowledge. An epicyclic gearbox can include, for example one or more (e.g., only one in some cases) input shaft and one or more (e.g., only one in some cases) output shaft, and a plurality of sets of gears, such as two, three, four, five, or more gears, or ranges including any two of the foregoing values. In some embodiments, the gearbox can include exactly three, or three or more sets of gears: sun gears, planet gears and rotor gears. In some embodiments, an epicyclic gearbox can include, or have exactly one input and two coaxial output drive shafts that are contra-rotating, including sun gears and planet gears, but not ring gears. In some embodiments, a gearbox can include any number of sun gears, planet gears, rotor gears, and/or ring gears. In some embodiments, a gearbox does not include one or more of sun gears, planet gears, rotor gears, and/or ring gears.

[0238] The input to the gearboxes can be via sun gears, both driven by one center shaft. For instance, the downstream impeller may be driven by the planet carrier of the downstream epicyclic gearbox (ring fixed), and the upstream impeller may be driven by the ring of the upstream epicyclic gearbox (planet carrier fixed to nose cone, and via struts to stationary motor casing) to achieve contra rotation. The gear ratios can be adjusted by the diameters of their internal components to achieve exact contra-rotation, i.e. the rpm of the two rotors is equal and opposite. Alternatively, the diameters of internal gear components can be used to make the rpm of the downstream rotor higher or lower than the rpm of the upstream rotor, to accommodate contra-rotation at different impeller rpm, for example for optimal flow dynamics or for balancing reasons.

[0239] Some illustrations of devices are included in FIGS. 1A-13. In some embodiments, features described as related to temporary devices may be incorporated into permanently implantable devices and features described as related to permanently implantable devices may be incorporated into temporary devices. Temporary devices may include any feature of any device described herein. Permanent devices may include any feature of any device described herein.

[0240] In some embodiments, devices may include two or more foldable impellers or propellers rotating in opposite directions, e.g., contra-rotation with respect to each other. In some embodiments, contra-rotating blades rotate with equal and opposite rpm. In some embodiments, contra-rotating blades rotate with unequal rpm. The impellers, and surrounding support, are placed in the folded position via a catheter in the aorta upstream of the kidneys. In some methods of use, this may be in the descending aorta, or further upstream in the aorta, anywhere up to the aortic valve. Once the catheter is removed the blades and surrounding support spring into the unfolded position. In some methods of use, the temporary device is removed via the reverse procedure by folding it and capturing it into a catheter.

[0241] Contra-rotation blades may have unequal rpm. Contra-rotation blades may have equal rpm. In some embodiments, embodiments of the gearboxes described herein can produce the rpm configuration, either equal rpm or unequal rpm. Contra-rotation blades rotate in opposite directions. As described herein, contra-rotation does not necessarily mean equal and opposite rpm, just opposite directions of rotation. In some embodiments, a mechanical circulatory support heart-assist device is provided which comprises two impellers rotating in opposite directions. In some embodiments, a mechanical circulatory support heart-assist device is provided which comprises at least two impellers (e.g., two, three, four, five, six, seven, eight, or any range of the foregoing values). In some embodiments, two of the at least two impellers are configured to rotate in opposite directions. The contra-rotation impellers may be adjacent in an axial direction. The contra-rotation impellers may be spaced apart in an axial direction. The contra-rotation impellers may be separated by one or more additional impellers in an axial direction. The contra-rotation impellers may be separated by one or more additional mechanical structures in an axial direction. The contra-rotation impellers may be separated by one or more support structures in an axial direction.

[0242] In some embodiments, devices described herein are placed in the vasculature in order to assist with perfusion. In some embodiments, devices described herein are placed in the vasculature to assist with opening a heart valve. The device may be placed to hold one of the four heart valves in an open position.

[0243] Some devices may be connected to a motor, which may have its own internal speed-reducing gearbox. The motor may be integrally connected to the devices intra-corporeally, or connected via a short bending shaft to the devices intra-corporeally. In some embodiments, power will be delivered to the motor via an electric cable. In some embodiments, the impellers and gearbox achieving contra-rotation are placed intra-corporeally in the descending aorta, and they are connected to an extra-corporeal motor or gear motor via a flexible drive shaft. The contra-rotating blades may have unequal rpm or equal rpm, based in part on the associated gearboxes. The electric motor may have integral with it an epicyclic gearbox reducing motor rpm the first time, e.g., a gear motor, then additional gearboxes reduce the motor rpm a second time before the impellers. In some embodiments, rotation of the two impellers in opposite directions is achieved via a gearbox. This gearbox may be just upstream of the impellers, just downstream of the impellers, or between the impellers. The gearbox receives input power and rotation from one shaft, and provides output via one or more two contra-rotating shafts to the two impellers.

[0244] The electric motor may have integral with it an epicyclic gearbox. The epicyclic gearbox may reduce motor rpm the first time. In some embodiments, this electric motor may be described as a gearmotor. In some embodiments, an additional gearbox reduces the motor rpm a second time before the impellers. The epicyclic gearboxes may be different types. The epicyclic gearboxes may be referred to by different names. For instance, in the case in which the sun is the input, planet carrier is the output, and ring gear is fixed, this type of gearbox may be referred to as planetary. For instance, in the case in which the planet carrier is fixed and ring moving, this type of gearbox may be referred to as star. Other configurations of fixed and movable components may have different names in the art.

[0245] In some embodiments, contra-rotation of impellers is achieved with one or more gearboxes. In some embodiments, a gearbox may be placed near the pump head. The gearbox may have two concentric output shafts driving the impellers in opposite directions. The gearbox may have one input shaft connected via a flexible shaft to an electric motor or gearmotor. The electric motor or gearmotor may be intracorporeal. The electric motor or gearmotor may be extracorporeal. In some embodiments, the upstream impeller is driven by an epicyclic-type gearbox. The downstream impeller may be driven in the opposite direction to the upstream impeller by a second epicyclic-type gearbox. The suns of both epicyclic gearboxes may be driven by sun gears connected via an input shaft to an electric motor. Other configurations are contemplated.

[0246] The input to the gearboxes can be via sun gears, both driven by one center shaft. For instance, the downstream impeller may be driven by the planet carrier of the downstream epicyclic gearbox (ring fixed), and the upstream impeller may be driven by the ring of the upstream epicyclic gearbox (planet carrier fixed to nose cone, and via struts to stationary motor casing) to achieve contra rotation. The gear ratios can be adjusted by the diameters of their internal components to achieve exact contra-rotation, i.e. the rpm of the two rotors is equal and opposite. Alternatively, the diameters of internal gear components can be used to make the rpm of the downstream rotor higher or lower than the rpm of the upstream rotor, to accommodate contra-rotation at different impeller rpm, for example for optimal flow dynamics or for balancing reasons.

[0247] In some embodiments, the device is a fully-removable temporary heart-assist device installed in a blood vessel. In some embodiments, the device is not across the aortic valve. In the unfurled position, the impeller tip diameter is 0.2 to 1.0 times the diameter of the adult-sized blood vessel. In some embodiments, the impeller tip diameter is about, at least about, or no more than about 0.1 times the diameter of the adult-sized blood vessel, 0.2 times the diameter of the adult-sized blood vessel, 0.3 times the diameter of the adult-sized blood vessel, 0.4 times the diameter of the adult-sized blood vessel, 0.5 times the diameter of the adult-sized blood vessel, 0.6 times the diameter of the adult-sized blood vessel, 0.7 times the diameter of the adult-sized blood vessel, 0.8 times the diameter of the adult-sized blood vessel, 0.9 times the diameter of the adult-sized blood vessel, 1.0 times the diameter of the adult-sized blood vessel, 1.1 times the diameter of the adult-sized blood vessel, 1.2 times the diameter of the adult-sized blood vessel, 1.3 times the diameter of the adult-sized blood vessel, 1.4 times the diameter of the adult-sized blood vessel, 1.5 times the diameter of the adult-sized blood vessel, 1.6 times the diameter of the adult-sized blood vessel, 1.7 times the diameter of the adult-sized blood vessel, 1.8 times the diameter of the adult-sized blood vessel, 1.9 times the diameter of the adult-sized blood vessel, 2.0 times the diameter of the adult-sized blood vessel, between 0.1 and 0.5 times the diameter of the adult-sized blood vessel, between 0.5 and 1 times the diameter of the adult-sized blood vessel, or any ranges including two of the foregoing values. In some embodiments, the devices be configured with a tip dimeter of about, at least about, or no more than about 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, 10.5 mm, 11 mm, 11.5 mm, 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5 mm, 15 mm, between 1 mm and 5 mm, between 3 mm and 7 mm, or any ranges including two of the foregoing values. In some embodiments, the device is a folding device. In some embodiment, the device has solid blades. In some embodiments, the closed device is about, at least about, or no more than about 5 Fr, 6 Fr, 7 Fr, 8 Fr, 9 Fr, 10 Fr, 11 Fr, 12 Fr, 13 Fr, 14 Fr, 15 Fr, 16 Fr, 17 Fr, 18 Fr, 19 Fr, 20 Fr, 21 Fr, 22 Fr, 23 Fr, 24 Fr, 25 Fr, 26 Fr, 27 Fr, 28 Fr, 29 Fr, 30 Fr, 31 Fr, 32 Fr, 33 Fr, between 5 and 10 Fr, between 10 and 15 Fr, or any ranges including two of the foregoing values. In some embodiments, the open device is about, at least about, or no more than about 10 Fr, 11 Fr, 12 Fr, 13 Fr, 14 Fr, 15 Fr, 16 Fr, 17 Fr, 18 Fr, 19 Fr, 20 Fr, 21 Fr, 22 Fr, 23 Fr, 24 Fr, 25 Fr, 26 Fr, 27 Fr, 28 Fr, 29 Fr, 30 Fr, 31 Fr, 32 Fr, 33 Fr, between 15 and 20 Fr, between 20 and 25 Fr, or any ranges including two of the foregoing values.

[0248] In some embodiments, the device is collapsible. In some embodiments, the device is inserted through a catheter. In some embodiments, the device is expanded. In some embodiments, the device can deliver a blood flow and pressure rises as described herein. In some embodiments, the device can be inserted percutaneously. In some embodiments, the device can provide continuous axial flow by pumping blood from the left ventricle into the ascending aorta. In some embodiments, the device is a mechanical circulatory support system. In some embodiments, the device generates antegrade flow. In some embodiments, the device has a collapsible impeller. In some embodiments, the device is expandable about twice the initial configuration. In some embodiments, the device is expandable when unsheathed. In some embodiments, the device is driven by one or more motors, which can be internal or external. In some embodiments, the device is driven by one or more flexible drive shafts. In some embodiments, the device includes a cage or anchor to support the impellers.

[0249] The device is a next generation of temporary heart-assist devices (TAD), providing treatment for early or imminent heart failure during Percutaneous Coronary Intervention (PCI), Primary PCI (during PCI for heart attack), and support for renal failure during episodes of cardio-renal syndrome, using a new technology placed via a minimally invasive procedure. Clinical conditions that may need TAD include primary and high-risk percutaneous coronary intervention (PCI); cardiogenic shock; acute decompensated heart failure (ADHF); cardio-renal syndrome (CRS) (no other device addresses this); acute heart failure (AHF); and/or recurring events in many of the above cases. There is a need for a new and innovative temporary cardiovascular support device. There is a need to overcome shortfalls with the current catheter based technology which can include one or more of the following disadvantages: has a narrow fluid channel, doesn't increase blood pressure, causes significant damage to blood cells, and can't support renal function. This is an Underpenetrated and growing market with a huge unmet need. For instance, high-risk PCI patients have twice the mortality risk compared to other PCI patients using current technology and mortality risk of cardiogenic shock patients post AMI remains high at 50%.

[0250] TAD can include one or more of the following advantageous features. TAD can be placed in the descending aorta in the collapsed profile and unsheathed in situ. TAD can be driven by an external gearbox and motor. TAD can include self-stabilisation and anchoring, minimizes aortic wall trauma. TAD can be positioned in a descending aorta location. TAD can be delivered with a 12 Fr delivery system. TAD can include foldable blades and cage. TAD can be removable. TAD can include a contra-rotating pair of propeller blades. TAD can accommodate varying aorta sizes, where one size fits all. TAD can include a constant waist diameter for optimized efficiency. TAD can include a permeable inlet. This inlet can perfuse intercostal and spinal arteries. TAD can include low rotation speed which reduces hemolysis. TAD can include an optimized blood flow path in each component. TAD can prevent or eliminate backflow, with no recirculation. TAD can include a flexible drive shaft. TAD can include an external gear box and motor. TAD is the only device that adds significantly to downstream pressure and flow. This feature supports renal function and improves cardio-renal failure. TAD can be temporary. TAD is designed for use from a few hours and up to 5 days. TAD can include a cage. The propeller section of the cage can be shape memory material such as Nitinol. The cage can surround the impellers. TAD can include foldable propeller blades. The foldable blades can be shape memory material such as Nitinol. The foldable blades can have a unique folding propeller design. The propeller blades can be stowed for delivery. The propeller blades can form a nested configuration around the hub for delivery. The blades can expand outward in use. TAD can include bidirectional rotating propeller blades. The blades can be mounted on a unique bidirectional drive shaft attached to a gearbox.

[0251] In some embodiments, TAD has structures which active these clinical performance features. TAD can include an inlet structure and/or cage structure which facilitate anchoring. TAD can include structures which minimize wall contact such as vanes or other diffusor structures. The radial forces just sufficient to hold rotating shaft radially. The axial thrust partially held by friction against aortic wall (and possibly partially by axial shaft). In some embodiments, TAD is inserted and/or retrieved in folded position. TAD can include folding blades. TAD can include a folding waist or compressible structure. TAD can include a folding inlet. TAD can include a folding vane structure or outlet diffuser. TAD can include a catheter for retrieval. In some embodiments, blades folded upstream. In some embodiments, blades folded upstream downstream. The blades can be folded or facilitated to be folded by daggers from hub. The blades can be built up around daggers. In some embodiments, the cage of memory alloy is covered by biocompatible material. TAD can include contra-rotating pair of propeller blades. The blades can remove vortex of first rotor. The blades can convert flow to axial or leave a small vortex. All energy imparted to blades can be converted to downstream axial energy and momentum, thus minimizing flow-friction losses and maximizes efficiency, and maximizes perfusion. In some embodiments, these high efficiency blades are not magnetic. In some embodiments, these high efficiency blades need to fold upstream or downstream. TAD can include a permeable inlet structure. The inlet shape can optimized for flow, and for perfusion in inter-costal arteries. The inlet can supports renal function and improves cardio-renal failure, as organs need perfusion.

[0252] In some embodiments, the pressure downstream of impellers is higher than the pressure upstream of impellers. If the gap between rotor tips and surrounding casing is too large, there is a lot of backflow from downstream to upstream. If the gap is too small, there is too much friction. Thus optimizing the gap is important for minimizing backflow around the gap, minimizing friction, and optimizing efficiency. Concurrently, the set rotor tip diameter and set waist diameter optimizes performance in the waist. Then the inlet section, and outlet diffuser section, enable the one-size fits all or most. Optimal efficiency can be from waist aspects, but also can be from inlet size, and outlet diffuser size, rotor gap size, among other features. The total energy imparted from device to blood is the minimum (ideal) energy imparted to blood to achieve pressure rise and flow rate, plus the losses. The losses do not contribute to perfusion (pressure and flow), but they are converted to blood trauma (which leads to hemolysis). Thus all the above (contra-rotating blades, outlet diffuser, optimal gap, etc.) can contribute to lower total energy by minimizing losses, and lower hemolysis by minimizing losses. In some embodiments, there is no backflow. There can be a constant gap between rotor tip and inner diameter of waist section.

[0253] In some embodiments, TAD is drive with a unique drive system. TAD can include a flexible drive shaft. The drive shaft can allow insertion in blood vessel. The drive shaft can allow placement of pump head in descending aorta. There can be variations in placement of the gearbox. An external gearbox can require a contra-rotating drive shaft from motor to near pump head. An intra-corporeal gearbox can allow a single drive shaft to gear box, and two shafts from gearbox to pump head. The drive shaft can be lubricated. The drive shaft can be unlubricated. The drive shaft can be coated. TAD can include an extra-corporeal gear box and/or motor. TAD can include an intra-corporeal gear box and/or motor. TAD can add to both downstream pressure and flow. Other devices may only impact flow rate without pressure rice.

[0254] TAD can be temporary. TAD can be designed for use for 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 12 hours, 24 hours/1 day, 2 days, 3 days, 4 days, 5 days, between 1 and 5 days, less than 1 day, less than 5 days, or any ranges including two of the foregoing values.

[0255] FIGS. 1A-1G schematically illustrate examples of MCS devices 500 configured for installation in the lumen of a blood vessel. MCS devices 500 can be permanent or temporary implantable devices. In some embodiments, the MCS 500 may comprise one or more rotors 510. The rotor 510 can have any configuration of rotors described herein. In some embodiment, the rotor 510 may be designed to operate with a stator. The rotors 510 may comprise one, two, or more propellers 511. The propeller 511 can have any configuration of propellers described herein. The propellers 511 may comprise one or more radially extending blades 520 configured to transfer force to the blood flowing through the vasculature. The blades 520 can have any configuration of blades described herein. In some embodiments, the MCS 500 may comprise one or more impellers 200 described herein. The impellers 200 can have any configuration of impellers described herein.

[0256] FIGS. 1A and 1B illustrate an example of a MCS device 500 with two rotors 510. In some embodiments, the MCS devices 500 can include any number of rotors, e.g., one rotor, two rotors, three rotors, etc. In some embodiments, the MCS device 500 may comprise more than one rotor 510. In some embodiments, each rotor 510 may comprise a propeller 511 configured to rotate independently of the propellers of other rotors. In some embodiments, each rotor 510 may comprise a propeller 511 configured to rotate simultaneously with the propeller of another rotor.

[0257] Each propeller 511 includes a number of blades. In the illustrated example, each propeller 511 may include four blades 520. The propeller 511 may have two pairs of diametrically opposed blades 520. The four blades 520 may be circumferentially spaced, e.g., spaced apart by approximately 90 degrees. The four blades 520 may be unevenly spaced apart. In the illustrated example, each propeller 511 includes one row of blades. In some embodiments, the propeller 511 can include two or more rows of blades. In some embodiments, the blades of the impellers rotating in opposite directions have flexible connections to the impeller hubs. The flexible connections may accommodate insertion and removal with folded blades. The flexible connections may accommodate operation when the blades are unfolded. The flexible connections may be a shape memory structure disposed within the blades.

[0258] The propeller 511 may be comprised of one or more radially extending blades 520. In some embodiments, the blades 520 may be aligned at a given axial position of the MCS device 500. In some embodiments, the blades 520 may be axially spaced along the axis of the MCS device 500. In some embodiments, one or more rotors 510 may comprise more than one propeller 511. In some embodiments, one or more rotors 510 may comprise more than one row of blades 520. In some embodiments, the propellers 511 of the same rotor 510 may be configured to rotate simultaneously. The propellers 511 may impart a velocity on blood flowing through the vasculature in which the MCS device 500 is installed. The one or more rotors 510 may be aligned along an axial dimension of the blood vessel. The axial dimension may extend parallel to the overall direction of blood flow within the vessel (upstream to downstream) and define a central axis of the MCS device 500. The axis of rotation of the one or more rotors 510 may be aligned substantially along the central axis of the MCS device 500. The axis of rotation of each of the rotors 510 may be aligned such that they are coaxial.

[0259] In some embodiments, magnetic elements may be used in the blades. In some embodiments, the whole blades may be magnetic. In some embodiments, the blades can be driven by a coil outside of the blades. For example, the coil may be outside of the blood vessel or aorta for permanent implantation. For example, the coil may be located inside the vessel, for instance in a support structure. Because axial blades are smaller than helical blades, most of the blade (e.g., a majority of the blade) may be a magnet.

[0260] In some embodiments, the blades may be made of shape memory materials. The material of the blades may enable folding into or against the hub for implantation and/or removal. In some embodiments, the components of the MCS device must be able to carry the fluid and magnetic forces exerted on them. If the blades are too pliable, the blades will be unable to carry the fluid forces. For example, if blades can twist to become axial, centrifugal, or helical they may not be able to carry the fluid or magnetic force necessary to generate mixed axial and centrifugal flow characteristics, wherein centrifugal would be pure losses.

[0261] In some embodiments, the optimal number of blades may be 2, 3, 4, 5, or 6 blades per rotating blade row. In some embodiments, the propeller or impeller has 1 blade in a single blade row, 2 blades in a single blade row, 3 blades in a single blade row, 4 blades in a single blade row, 5 blades in a single blade row, or 6 blades in a single blade row, one row, two rows, or three rows, or any combination of the foregoing configurations. In some embodiments, the rotor may include 1, 2, 3, 4, 5, or 6 blade rows. Each blade row may be rotated by the same rotor.

[0262] In some embodiments, the optimum stagger angle may be between approximately 40 and 90 degrees from the hub direction. In some embodiments, the optimum stagger angle is between 40 and 50 degrees, between 50 and 60 degrees, between 60 and 70 degrees, between 70 and 80 degrees, between 80 and 90 degrees, between 40 and 60 degrees, between 50 and 70 degrees, between 60 and 80 degrees, between 70 and 90 degrees, between 40 and 70 degrees, between 50 and 80 degrees, between 60 and 90 degrees, or any range including any two of the foregoing values. In some embodiments, the MCS device may comprise an optimized number of blades. In some embodiments, the MCS device may comprise an optimized stagger angle of the blades.

[0263] MCS devices may include axial propeller type blades, as described elsewhere herein. Axial propeller type blades are generally distinct from helical screws, in that they comprise distinct turbomachine geometries. Cutting azimuthal segments of helical devices does in some cases not result in as efficient 3D axial turbomachines as turbomachines comprising axial propeller type blades.

[0264] The MCS device 500 may comprise an anchoring mechanism 600 for anchoring the turbomachinery within the aorta or blood vessel. The anchoring mechanism 600 may be a cage, circumferential band, or other support structure configured to surround the turbomachinery and to allow blood flow to pass through. In some embodiments, the cage structure may comprise upstream and downstream points substantially aligned with the axis of rotation of the one or more rotors 510. The anchoring mechanisms 600 may be configured to hold the MCS device 500 in place within the blood vessel through pressure exerted on the blood vessel wall at points where the anchoring mechanism 600 contacts the blood vessel. The anchoring mechanism 600 may be expandable as described elsewhere herein.

[0265] For temporary devices, the anchoring mechanism 600 may be designed to temporary anchor the device within the aorta or blood vessel. The anchoring mechanism 600 may be atraumatic to rest against the vessel wall. For permanent devices, the anchoring mechanism 600 may be designed to permanently engage the tissue of the patient. The anchoring mechanism 600 may take on various forms to achieve the desired level of fixation.

[0266] FIG. 1A illustrates a collapsed configuration. FIG. 1B illustrates an expanded configuration. The MCS devices 500 may have one or more intermediate configurations between the collapsed configuration and the expanded configuration. In the collapsed configuration, the one, two, or more blades are configured to collapse to a low profile configuration. In the expanded configuration, the one or more blades are moved laterally outward. In some embodiments, the MCS device may be implanted in a collapsed state and deployed inside descending aorta, ascending aorta, or left ventricle via the aortic valve.

[0267] FIGS. 1C and 1D illustrate the MCS devices 500 within a blood vessel 150. FIGS. 1C and 1D schematically illustrate the surgical installation of the MCS device 500. In FIG. 1C, the anchoring mechanism 600 is removed, showing the rotors.

[0268] FIG. 1E illustrate a perspective view of the MCS devices 500 with two rotors 510. Each rotor 510 includes a propeller 511 that includes three blades 520. The three blades 520 may be circumferentially spaced, e.g., spaced apart by approximately 120 degrees. In some embodiments, one or more propellers 511 include a single blade. In some embodiments, one or more propellers 511 include two blades. The two blades 520 can be circumferentially spaced, e.g., spaced apart by approximately 180 degrees, or unevenly space. In some embodiments, the two or more propellers 511 have the same number of blades. In some embodiments, the two or more propellers 511 have the same configuration of blades, such as the same spacing between blades. In some embodiments, the two or more propellers 511 have a different number of blades. In some embodiments, the two or more propellers 511 have a different configuration of blades, such as different spacing between blades.

[0269] In some embodiments, the anchoring mechanism 600 may have a barrel-shape configuration as shown in FIG. 1E. In some embodiments, the anchoring mechanism 600 can be designed to minimize contact with the vessel wall. In some embodiments, the anchoring mechanism 600 is the point or points of contact with the vessel wall. In some embodiments, the anchoring mechanism 600 may act as a centering mechanism for the rotors.

[0270] FIG. 1F illustrates an example of a contra rotors device including a pair of contra-rotating propellers 512, 514. In some embodiments, the second propeller 514 may reverse the direction of the tangential velocity component. In some embodiments, the second propeller 514 may add to the axial velocity component of the blood flow such that the axial velocity of the blood is continually increased as it passes through the MCS device 500. In some embodiments, MCS devices 500 may include contra-rotating blades. Contra-rotating blades may be highly beneficial to minimize hemolysis. Contra-rotating blades may be able to operate efficiently at a lower rpm than devices without contra-rotating blades. The MCS devices 500 can include any number of propellers, including any number of contra-rotating propellers. The MCS devices 500 can include any arrangement of propellers, including any arrangement of contra-rotating propellers. In the illustrated embodiment, the pair of contra-rotating propellers 512, 514 are axially aligned. In the illustrated embodiment, the pair of contra-rotating propellers 512, 514 have the same number of blades. In the illustrated embodiment, the pair of contra-rotating propellers 512, 514 have blades that are equally spaced around the circumference.

[0271] In some embodiments, the magnitude of angular velocities of two propellers within a pair of contra-rotating propellers 512, 514 may be equal. Contra-rotating propellers 512, 514 with equal angular velocity magnitudes may result in output velocity vectors comprising small tangential velocity components, such as that necessary to replicate natural helical blood flow in the aorta. In some embodiments, the magnitude of angular velocities of two propellers within a pair of contra-rotating propellers 512, 514 may be unequal.

[0272] The final velocity vector at the output of the MCS device 500 may be modulated by the blade geometry. The blades of the propeller 511 and/or the contra-rotating propellers 512, 514 can be selected to have the desired flow characteristics. The blades of the propeller 511 and/or the contra-rotating propellers 512, 514 can be selected based on the size of the blades. The blades of the propeller 511 and/or the contra-rotating propellers 512, 514 can be selected based on the tilt of the blades. The blades of the propeller 511 and/or the contra-rotating propellers 512, 514 can be selected based on the total number of blades of the propeller. The blades of the propeller 511 and/or the contra-rotating propellers 512, 514 can be selected based on the direction of rotation of the propeller 511 and/or the contra-rotating propellers 512, 514.

[0273] The blades of the propeller 511 and/or the contra-rotating propellers 512, 514 can be selected based on the desired distance between the two or more propellers 511 and/or contra-rotating propellers 512, 514 in the MCS device 500. The blades of the propeller 511 and/or the contra-rotating propellers 512, 514 can be selected based on the ordering of the propellers in an axial direction in the MCS device 500. The blades of the propeller 511 and/or the contra-rotating propellers 512, 514 can be selected based on the desired number of propellers to achieve a blood flow characteristic. The blades of the propeller 511 and/or the contra-rotating propellers 512, 514 can be selected based on the desired angular velocities of the propeller 511 and/or the contra-rotating propellers 512, 514 to achieve a blood flow characteristic.

[0274] In some embodiments, the propellers 511, the contra-rotating propellers 512, 514, impellers, or contra-rotating impellers may have a diameter taking most of the available blood vessel diameter. This configuration can have advantages. The RPM of the one or more propellers or impellers may be minimized for the pressure rise and flow rate specification, thus minimizing blood trauma. In some embodiments, the propellers 511, the contra-rotating propellers 512, 514, impellers, or contra-rotating impellers may have a diameter less than the available blood vessel diameter. In some embodiments, one or more support structures have a diameter that fills a portion of the available blood vessel diameter.

[0275] In some embodiments, the propellers 511, the contra-rotating propellers 512, 514, impellers, or contra-rotating impellers are coupled to a motor. The motor can have any features of motors described herein. MCS device 500 can include any structure or hub to contain or house the motor. In some embodiments, one or more contra-rotating motors may be located in the hub of propellers or impellers. MCS device 500 can include any structure to deliver power to the motor. MCS device 500 can include any structure to deliver control signals to the motor. In some embodiments, one or more catheter based conduits are provided for carrying conductors for power delivery and control signals.

[0276] TAD can include contra-rotating impellers. In some embodiments, the impellers rotate in opposite directions, as viewed from an external reference point. In some embodiments, one impeller rotates clockwise and the other impeller rotates counter-clockwise. In some embodiments, the impellers rotate in the same direction, as viewed from an external reference point. In some embodiments, both impellers rotate clockwise. In some embodiments, both impellers rotate counter-clockwise. In some embodiments, the impellers face opposite directions, as viewed from an external reference point. In some embodiments, the impellers are mounted end-to-end. In some embodiments, the impellers face the same direction, as viewed from an external reference point. In some embodiments, the impellers are mounted end-to-face. In some embodiments, the impellers are of opposing handedness, as viewed from an external reference point. In some embodiments, one of the impellers is a left-handed impeller and the other impeller is a right handed impeller. In some embodiments, the impellers have the same handedness, as viewed from an external reference point. In some embodiments, both of the impellers are a left-handed impellers. In some embodiments, both of the impellers are right handed impellers. In some embodiments, the contra-rotating impellers are within the same cage. In some embodiments, the contra-rotating impellers pump blood in the same direction. In some embodiments, the contra-rotating impellers pump blood in opposite directions.

[0277] FIG. 1G illustrates an example of a single rotor with a pre-swirler 540 and a de-swirler 542. The MCS device 500 can include one or more pre-swirlers. The MCS device 500 can include one or more de-swirlers. The pre-swirlers and de-swirlers may comprise 3D conformations. The blades may include a complex 3D configuration. This configuration of the pre-swirlers may impart a desired flow characteristic on the blood prior to entry into the propeller. This configuration of the de-swirlers may impart a desired flow characteristic on the blood after engagement with the propeller.

[0278] The pre-swirlers and de-swirlers may provide improved hydrodynamics over simple 2D struts. For example, 2D struts may not be able to impart the desired flow characteristics. In some embodiments, the pre-swirlers and/or de-swirlers are compared to those which are 2D in shape. These 2D struts may be extruded from a tube. These 2D struts may have poor flow characteristics. In contrast, the 3D pre-swirl and de-swirl vanes may be configured to have vane-angle changes from hub to tip. This configuration can impart better flow characteristics on the blood. In some embodiments, the 3D pre-swirl and de-swirl vanes are not planar. In some embodiments, the 3D pre-swirl and de-swirl vanes extend in three planes. In some embodiments, the 3D pre-swirl and de-swirl vanes extend in multiple directional vectors in a thickness dimension. In some embodiments, the 3D pre-swirl and de-swirl vanes have a longitudinal twist. In some embodiments, the 3D pre-swirl and de-swirl vanes have a longitudinal curvature.

[0279] The pre-swirlers and de-swirlers may have a compressed configuration and an expanded configuration, similar to the blades. The pre-swirlers and de-swirlers may be foldable against a hub or other structure of the MCS device 500. In some embodiments, the pre-swirlers and de-swirlers may be removable from the remainder of the device. In some embodiments, the pre-swirlers and de-swirlers may be permanently coupled to the device.

[0280] FIGS. 2A-2C illustrate an anchoring mechanism 600 for anchoring the turbomachinery within the blood vessel. FIG. 2A illustrates a folded device 500 with a deflated balloon. FIGS. 2B and 2C illustrate an unfolded device 500 with an inflated balloon. The anchoring mechanism 600 may include a balloon configured to surround the turbomachinery and to allow blood flow to pass through. The balloon can be selectively inflated within the blood vessel or aorta. In some embodiments, the balloon fills a portion of the diameter of the blood vessel. In some embodiments, the balloon is designed to rest against the blood vessel and be a point of contact with the blood vessel. The anchoring mechanism 600 may also include one or more struts. The struts can rest against the inside diameter of the balloon. The struts can center the turbomachinery within the lumen of the balloon.

[0281] In some embodiments, the balloon may have a tube configuration as shown in FIG. 2C. In some embodiments, the balloon may comprise an upstream and downstream periphery substantially offset from the axis of rotation of the one or more rotors 510. The balloon may be configured to hold the MCS device 500 in place within the blood vessel through pressure exerted on the blood vessel wall at the side surface where the balloon contacts the blood vessel. The balloon may be expandable such as through inflation medium. In some methods of use, the balloon is inflated when within the blood vessel or aorta. The inflation medium can be delivered through one or more conduits to the balloon. The inflation medium can be a biocompatible material such as saline. In some embodiments, the inflation medium is a gas. In some embodiments, the inflation medium is a liquid. In some embodiments, the inflation medium is a solid, solid-forming, or curable material. The balloon may be expandable by absorption of liquid, such as blood. In some embodiments, the balloon is permeable to liquid allowing the balloon to expand. In some embodiments, the balloon can be deflated. In some embodiments, the balloon is configured to be a permanent structure within the body of the patient.

[0282] FIGS. 3A-3B illustrate intra-corporeal motors. The MCS device 500 may comprise one or more motors 700 coupled to the one or more rotors 510 to provide rotational force to the one or more rotors 510. In embodiments comprising more than one rotor 510, some or all of the rotors 510 may be driven by different motors. FIG. 3B illustrate a plurality, e.g., two intra-corporeal motors 700 positioned back to back. Each intra-corporeal motor 700 provides rotational force to an independent rotor. The two intra-corporeal motors 700 are positioned within a sealed capsule 550 to prevent the passage of blood into the motors 700. FIG. 3A illustrates the assembled device with the sealed capsule. For TAD, the motor can be easily removed with the removal of the device.

[0283] FIG. 3C illustrates a magnetic coupling 552. The magnetic coupling is illustrated between the rotor 510 and the motor 700. The rotor is the hub of the propeller and provides a location for coupling to the motor. The coupling can be any mechanical couple to transmit rotational movement from the motor to the rotor. In some embodiments, the rotor and/or propeller may be coupled to the motor by any magnetic means. In the illustrated embodiment, magnets are provided on the rotor and the motor. In some embodiments, the rotor and/or propeller may be directly rotated by the motor stator and may be referred to as part of the motor 700. For instance, magnets driven by the electromagnetic stator of the motor may be coupled to or installed within the rotor or rotors 510. Other configurations of coupling are contemplated. In some embodiments, the coupling of the turbomachine to the motor may be accomplished via a shaft. In some embodiments, the coupling of the turbomachine to the motor may be accomplished via magnetic coupling.

[0284] In some embodiments, there is provided one or more couplings between the motors, where multiple motors are provided. The coupling between the motors may be via magnetic coupling, connectors, and/or bearings. In some embodiments, bearings at the proximal and distal end of the MCS device may be hydrodynamic. In some embodiments, bearings at the proximal and distal end of the MCS device may be magnetic. In some embodiments, bearings at the proximal and distal end of the MCS device may be self-lubricating using circulating blood.

[0285] FIG. 3D illustrates another embodiment of a motor. One or more epicyclic gears 554 (also known as planetary gears) may be used to achieve contra-rotation between the two rotors. Other configurations of motors are contemplated.

[0286] FIG. 3E illustrates lubrication channels 556. In some embodiments, a lubricating fluid may be provided through the catheter to lubricate the driveline. For example, a lubricating fluid may be transported through small channels in the catheter to a proximal bearing of the rotor 510 and returned through a line comprising the driveline. In some embodiments, the distal bearing of the rotor 510 may be lubricated by blood flow.

[0287] FIGS. 4A-4C illustrate the MCS device 500 positioned within a blood vessel 150. The MCS device 500 can be inserted in a low profile configuration until the MCS device 500 reaches a target vessel. The MCS device 500 can be unfolded or deployed to expand the one or more blades 520. In embodiments comprising an intra-corporeal motor, the motor or motors may be positioned within the lumen of the blood vessel (intravascular).

[0288] FIG. 5A illustrates articulated sleeves for insertion 560. The articulated sleeves can allow the MCS device 500 to bend as the MCS device 500 travels to the target vessel. FIG. 5B illustrates tail to tail motors 700 within the articulate sleeve 560. The motors 700 can be positioned tail to tail to operate rotors at each end of the sleeve. FIG. 5C illustrates head to tail motors 700 within the articulate sleeve. The motors 700 can be positioned in any configurations within the articulate sleeve or other capsule. The motors can be easily removed with the removal of the device.

[0289] FIGS. 6A-6B illustrate the opening of blades in an umbrella-like fashion. FIG. 6A illustrates partial opening in a smaller aorta. The blades form an angle of about 135 degrees with the longitudinal axis of the MCS device 500. FIG. 6B illustrates full opening in a larger aorta. The blades form an angle of 90 degrees with the longitudinal axis of the MCS device 500. The tip diameter of the propeller is smaller in FIG. 6A than in FIG. 6B. The MCS device may be configured to maintain a substantially constant gap size between the blade tips and the anchoring mechanism regardless of size of the aorta. In some embodiments, the MCS device 500 can include an impeller designed to open in an umbrella-like fashion. In some embodiments, the blades of the impellers have flexible connections to the corresponding impeller hubs. The flexible connections may facilitate insertion and removal with folded blades. The flexible connections may facilitate operation when the blades are unfolded. In some embodiments, the mechanical folding mechanism for the blades is like an umbrella. In some embodiments, the mechanical folding mechanism may include a runner and a stretcher. In some embodiments, the mechanical folding mechanism may include a screw and cam. In some embodiments, the mechanical folding mechanism can include a locking mechanism that locks the blades in an open configuration. In some embodiments, the mechanical folding mechanism can include a locking mechanism that locks the blades in a closed configuration. In some embodiments, the mechanical folding mechanism can by any mechanism that folds and unfolds the blades. In some embodiments, the blades are folded and unfolded by the action of a larger catheter or sheath.

[0290] In some embodiments, the MCS device 500 may include one or more foldable propellers and/or impellers. The foldable impellers may be inserted collapsed against the hub of the device, and then opened in an umbrella-like fashion at the desired aortic location to various degrees. The tip diameter of the impeller or propeller varies by the amount of opening of the umbrella. The propellers or impellers may be enclosed within a cage or other anchoring mechanism 600. The propellers or impellers may open partially to a variable umbrella opening, resulting in variable tip diameter. The umbrella design may keep the turbomachine tip-to-cage gap at optimum levels as described herein. The MCS device 500 may comprise an adjustable operating impeller or propeller diameter configured to maintain a substantially constant gap size between the blade tips and the anchoring mechanism. The MCS device 500 may comprise an adjustable operating impeller or propeller diameter configured to maintain a substantially constant gap size between the blade tips and the blood vessel wall. In some embodiments, the MCS device 500 has a variable impeller diameter to maintain the desired gap with a one size impeller.

[0291] In some embodiments, the impellers or propellers of the MCS device 500 may be intended to be either fully open or fully closed. The impellers or propellers of the MCS device 500 possess a fixed tip diameter in the open position. This embodiment can be an alternative to the umbrella-like opening described above. The diameter of the fixed diameter propellers or impellers may be set, for example, at approximately 10 mm, 12 mm, 14 mm, 16 mm, 18 mm, 20 mm, 22 mm, 24 mm, 26 mm, 28 mm, 30 mm, 32 mm, between 10 mm and 20 mm, between 20 mm and 30 mm, less than 30 mm, less than 22 mm, less than 20 mm, less than 18 mm, more than 10 mm, more than 14 mm, more than 16 mm, or any range including two of the foregoing values.

[0292] In some embodiments, the blades may be inserted in a collapsed state whether designed to partially open or fully open. The blades can be loaded into one or more sleeves for delivery. The blades may be spring-loaded and ready to expand upon removal of the sleeves. Once expanded to the full extent or to a partial extent, as described herein, the centrifugal action of rotation may keep the blades in an open configuration. In the case of partial opening, the blades may be locked in position. In some embodiments, the blades are locked from the hub side.

[0293] MCS devices may include a tip-diameter dimension. The interior diameter of the aorta at the implantation location varies from patient to patient, for instance, between approximately 20 mm and 32 mm. This varying dimension may present a series of problems, as there is generally a desire to limit the gap between the propeller or impeller tip and the surrounding device or blood vessel structure. Optimal gaps, balancing requirements between hydraulic efficiency and hemolysis, may be between approximately 0.2 and 2 mm, e.g., 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 2 mm or any range including two of the foregoing values. Optimal gaps, balancing requirements between efficiency and hemolysis, are between 0.2 and 1 mm, e.g., 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, or any range including two of the foregoing values. For example, in some embodiments, the preferred or nominal gap size may be approximately 0.5 mm. In some embodiments, the nominal gap size may be approximately 0.0 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, less than 0.7 mm, less than 0.5 mm, less than 0.3 mm, or any range including two of the foregoing values. Larger gaps may result in regurgitant flow from the device outlet to the device inlet, and thus reduced hydraulic efficiency, as well as increased mixing and hemolysis.

[0294] However, providing a device with a fixed large diameter to reduce the gap may make the device unsuitable (too large) to be accommodated in specific patient anatomies. In some embodiments, there is provided a customized device. In some embodiments, there is provided an adjustable size device. In some embodiments, the MCS device accommodates variable sized blood vessels using adjustability. In some embodiments, the MCS device is available in a potential matrix of device sizes, from smaller to larger diameters. In some embodiments, there is the ability to select a device from a range of device sizes from smaller diameters to larger diameters, to accommodate the desirable gaps in each case. In some embodiments, the MCS device is available in a variety of dimeter sizes in the fully open position to accommodate varying aorta sizes.

[0295] In some embodiments, the propeller or impeller can be designed to operate in conjunction with an expandable member, e.g., a balloon. FIGS. 2A-2C provide an example balloon. The MCS device may include a cylindrical-sleeve shaped balloon. The balloon may include an open center to accommodate along its axis the open (unfolded) propeller or impeller. The balloon can be used to adjust the size of the gap between the blade tips and the balloon. The internal diameter of the balloon can be varied via a level of inflation to adjust for the desired gap size as well as accommodate the propeller or impeller blades and balloon in the blood vessel.

[0296] In some embodiments, the balloon may serve as the anchoring mechanism for the MCS device. In some embodiments, the balloon may be coupled to an outer diameter of the cage or struts. In some embodiments, the balloon may be coupled to an inner diameter of the cage or struts. In some embodiments, two balloons may be used, one coupled to each side (internal, external) of the cage or struts. The MCS device may comprise an impeller or propeller having a fixed operative diameter as described herein. The impeller or propeller having a fixed operative diameter may be surrounded by a balloon that inflatable to various sizes such that the gap between the propeller or impeller tip and the inner diameter of the balloon is adjustable. In some embodiments, the inner diameter of the balloon is adjustable, such as the central lumen through which the turbomachinery passes. In some embodiments, the outer diameter of the balloon may be adjustable. The outer diameter may be advantageously adjusted to fit against the wall of the vessel.

[0297] By utilizing a cylindrical-sleeve type balloon with an open center to accommodate in its axis the open propeller or impeller, the balloon internal diameter can be varied to adjust for the desired gap size. By utilizing a cylindrical-sleeve type balloon, the balloon external diameter can be varied to fit the impeller plus balloon into the blood vessel. In some embodiments, the MCS device may have a variable impeller tip diameter and variable balloon inflation to accommodate blood vessel diameter while keeping tip-to-balloon gap at optimum levels balancing hemolysis with tip leakage. In some embodiments, the MCS device may have a few impeller size devices and variable balloon inflation to fit desired gap in varying blood-vessel diameters.

[0298] In some embodiments, the balloon may comprise an axial length configured to extend axially beyond the one or more propellers or impellers. In some embodiments, the balloon may comprise an axial length configured to extend distally beyond the one or more propellers or impellers. In some embodiments, the balloon may comprise an axial length configured to extend proximally beyond the one or more propellers or impellers. In some embodiments, the balloon may comprise an axial length configured to extend both proximally and distally beyond the one or more propellers or impellers. Extending the length of the balloon may optimize blood flow through the MCS device. This increased axial length can have many advantages including reducing hemolysis, protecting against backflow, optimizing fluid dynamics, and/or avoiding vortices.

[0299] The balloon may be a generally cylindrical tube like structure as illustrated herein. In some embodiments, the balloon is spherical. In some embodiments, the balloon is conical. In some embodiments, the balloon comprises two or more balloons. In some embodiments, the balloon comprises two or more axial balloons. In some embodiments, the balloon comprises two or more circumferential balloons. In some embodiments, the balloon comprises two or more circumferential lobes. For example, the balloon can include a cloverleaf design with four lobes. Other configurations are contemplated.

[0300] The balloon can include one or more surfaces configured to contact the blood vessel. The balloon can include one or more rounded edges. The balloon may comprise shaped inlet and/or outlet regions. For example, the inlet and/or outlet regions may be shaped as smooth-shaped bodies of revolution above and/or below the propeller or impeller structure. The inlet and/or outlet regions may be designed to smooth the inflow into the propeller/impellers and outflow out of the propeller or impellers. The inlet and/or outlet regions may be designed in a manner minimizing recirculating flow patterns, dead-flow regions, and/or minimizing losses. The inlet and/or outlet regions may be shaped with optimization techniques similar to aircraft inlets and diffusers. In some embodiments, the MCS device may include shaped balloon inlets and/or outlets.

[0301] The MCS device can include the cage or anchoring mechanism 600. The cage or anchoring mechanism 600 can be deployed in embodiments with or without a balloon. The cage or anchoring mechanism 600 can be deployed in embodiments with one or more rotors/propellers. The cage or anchoring mechanism 600 can be deployed in embodiments with one or more contra-rotating rotors/propellers. In some embodiments, the structures of the perimeter struts forming the cage or anchoring mechanism 600 may be shaped to open into 3D blades directing the flow in the desired direction. For example, the struts may form blades that extend in an axial and circumferential direction from proximal to distal ends. The blades may extend radially inward in a proximal to distal direction. The blades may extend radially outward in a proximal to distal direction. The blades may have a uniform thickness as they extend along the proximal to distal direction. The blades may have a variable thickness as they extend along the proximal to distal direction. The blades may have the same or similar features as pre-swirler and/or de-swirler blades described herein.

[0302] The MCS device can include one or more coils. The coils may be used in an addition to or alternatively to the balloon. In some embodiments, the coils can be used to form funnels (3D bodies of revolution) at the inlet and/or outlet of the MCS device. In some embodiments, the coils can provide strength to the balloon. In some embodiments, the coils can improve flow characteristics. In some embodiments, the coils can be provide at the inlet, the outlet, or both the inlet and the outlet. In some embodiments, the coils can serve the function as pre-swirlers and/or de-swirlers. In some embodiments, the coils can accommodate the differences in blood-vessel diameter from the tip and cage diameter. In some embodiments, the coils can be expanded and uncoiled, as well as compressed and stretched to change shape. In some embodiments, the coils can form the desired gap between the blade tips and the coils.

[0303] FIGS. 7A-7D illustrate an example of perimeter struts forming the cage or anchoring mechanism 600. In some embodiments, the impellers or propellers of the MCS device may be intended to be either fully open and possess a fixed tip diameter in the open position. In some embodiments, the impellers or propellers of the MCS device may be intended to be opened in an umbrella like fashion. FIG. 7A illustrates an embodiment of a collapsed configuration. The blades of the propeller are against the hub of the device. The anchoring mechanism 600 extends distally along the hub of the device. The anchoring mechanism 600 can include one or more hinges or other mechanical structures that enable the anchoring mechanism 600 to fold. FIG. 7B illustrates an embodiment of an expanded configuration of the embodiment of FIG. 7A. The blades of the propeller are laterally extended from the rotor. The anchoring mechanism 600 is also laterally extended. The propellers of the MCS device 500 may have a fixed tip diameter in the open position between the blade tips and the struts of the anchoring mechanism 600. In the illustrated embodiment, each strut of the anchoring mechanism 600 extends laterally away, then distally, then laterally toward the device. The strut forms two 90 degree angles or similar angles when expanded. Other configurations are contemplated. FIGS. 7A-7B illustrate an intra-corporeal motor with folding cage support.

[0304] FIG. 7C illustrates an embodiment of a collapsed configuration. The blades of the propeller are in a low profile, insertion, and/or removal configuration. FIG. 7D illustrates an embodiment of an expanded configuration of the embodiment of FIG. 7C. The blades of the propeller and the anchoring mechanism 600 are laterally extended. The propellers of the MCS device 500 may have a fixed tip diameter in the open position between the blade tips and the struts of the anchoring mechanism 600. The propellers of the MCS device 500 may have a variable tip diameter in the open position between the blade tips and the struts of the anchoring mechanism 600. In the illustrated embodiment, each strut of the anchoring mechanism 600 curves or forms an arch in the proximal-distal direction. Other configurations are contemplated. FIGS. 7C-7D illustrate an extra-corporeal motor with a thicker drive shaft. FIGS. 7A-7D illustrate the MCS device deployed in a blood vessel. FIGS. 7A-7D illustrate an intra-corporeal motor with folding cage support, and extra-corporeal motor (thicker drive shaft), both in a blood vessel.

[0305] In some embodiments, the MCS device may comprise pre-swirler and/or de-swirler stationary vanes. The pre-swirler and/or de-swirler stationary vanes may also serve as the support structures of the hub of the turbomachine. In some embodiments, the pre-swirler and/or de-swirler stationary vanes may form the cage or anchoring mechanism surrounding the one or more rotors. In some embodiments, the MCS device may comprise struts opening in blade shapes. The struts may function as the pre-swirler and/or de-swirler. The struts functioning as a pre-swirler and/or a de-swirler can have a 3D configuration when expanded. In some embodiments, the MCS device may comprise a simpler stator-rotor-stator configuration. In some embodiments, the MCS device may comprise one rotating impeller with upstream pre-swirler and downstream de-swirler stationary vanes. The upstream pre-swirler and downstream de-swirler stationary vanes may also be the support structures of the hub of the turbomachine to the cage or support around the rotor. In some embodiments, the MCS device may comprise support struts configured to open in blade shapes.

[0306] In some embodiments, more than one impeller or propeller may be positioned between pre-swirler and de-swirler stationary vanes (e.g., 2, 3, 4, 5, or more impellers or propellers). In some embodiments, one impeller or propeller may be positioned between pre-swirler and de-swirler stationary vanes. In some embodiments two or more contra-rotating impellers or propeller may be positioned between pre-swirler and de-swirler stationary vanes. In some embodiments, the stationary vanes may only serve the function of the pre-swirler. In some embodiments, the stationary vanes may only serve the function of the de-swirler.

[0307] Whether with one rotor or a pair of contra-rotating rotors, the structures of the perimeter struts forming the cage may be shaped to open into 3D blades. The 3D blades may be designed for directing the flow in the desired direction. In some embodiments, the MCS device may comprise pre-swirler and/or de-swirler struts to optimize flow angles and turbomachinery efficiency. The 3D blades can be pre-formed to have the desired configuration when expanded. The 3D blades can be formed of a shape memory material.

[0308] In some embodiments, the cage or anchoring mechanism 600 may be a solid cylinder. The cage or anchoring mechanism 600 may comprise one or more supporting rings at the proximal and distal end. The cage or anchoring mechanism 600 may comprise one or more supporting rings located at the axial location of the propeller or impeller tips. The cage or anchoring mechanism 600 may comprise axial elements between the supporting rings that expand to fit inside the blood vessel. The axial elements may be 3D blades. The cage or anchoring mechanism 600 may be made of flexible materials that expand to the required shape. In some embodiments, the MCS device may comprise a cage and/or supporting structure. In some embodiments, the MCS device may comprise an installation procedure including the deployment of a cage or anchoring mechanism 600.

[0309] In some methods of use, the cage or anchoring mechanism 600 may be implanted separately from the impeller device or other turbomachinery. In some methods of use, the cage or anchoring mechanism 600 can be implanted similar to a stent cage. The cage or anchoring mechanism 600 may comprise a balloon or other space-occupying feature. In some methods of use, the cage or anchoring mechanism 600 is expanded prior to insertion of the turbomachinery. The cage or anchoring mechanism 600 expands against the wall of the vessel. In some embodiments, the cage or anchoring mechanism 600 may include a central lumen for insertion of the turbomachinery. In some embodiments, the cage or anchoring mechanism 600 is designed to ensure the central lumen of the cage or anchoring mechanism 600 matches the diameter of the propeller or impeller with the appropriate gap. In some embodiments, the design ensures that there is not an excessive gap between the tip of propeller or impeller blades and the wall of vessel. In some embodiments, the design ensures that there is not an excessive gap between the tip of propeller or impeller blades and the wall of anchoring mechanism or cage in the stent tube configuration.

[0310] In some embodiments, MCS devices may include interior sleeves or stents. The sleeves or stents may be in one piece or multi-pieces. The sleeves or stents may be implanted against the interior blood vessel wall. The sleeves or stents may be implanted such that a supporting structure can be attached to hold the bearings and main shaft of the propellers or impellers. Other configurations of support structures are contemplated.

[0311] In some embodiments, if the stent cage is delivered independently, the impeller device may have pre-swirlers and/or post-swirlers. The pre-swirlers and/or post-swirlers may be self-expanding. The pre-swirlers and/or post-swirlers may be mechanically expanded disks. In some embodiments, the pre-swirlers and/or post-swirlers may function to centralize the propeller or impeller and prevent collision with vessel wall. In some embodiments, the pre-swirlers and/or post-swirlers may be collapsible for when removal is required. Variable diameters of blood vessel may be accommodated using different openings comprising 3D pre-swirlers and/or de-swirlers.

[0312] In some methods of use, the cage or anchoring mechanism 600 may be implanted simultaneously with the impeller device or other turbomachinery. In some methods of use, the cage or anchoring mechanism 600 and the blades can be expanded simultaneously. In some methods of use, the cage or anchoring mechanism 600 and the blades can be expanded independently and/or sequentially. In some methods of use, the cage or anchoring mechanism 600 and the blades can be expanded to varying degrees. In some embodiments, the design ensures that there is not an excessive gap between the tip of propeller or impeller blades and the wall of vessel and/or the wall of anchoring mechanism or cage.

[0313] In some embodiments, the MCS device may comprise two contra-rotating propellers or impellers. In some embodiments, such a configuration may result in maximum hydraulic efficiency. In some embodiments, such a configuration may result in minimum rotor RPM. In some embodiments, such a configuration may result in minimum hemolysis. In some embodiments, the MCS device may include a pair of contra-rotating impellers maximizing efficiency and minimizing hemolysis.

[0314] FIGS. 8A-8C illustrate a configuration comprising two contra-rotating propellers. FIG. 8A illustrates the bevel gearbox achieving contra-rotation. The first shaft moves clockwise and the second shaft moves counter clockwise. The support gears are also illustrated. The MCS device is shown in FIG. 8B. The positioning of the bevel gearbox is shown in FIG. 8C. FIGS. 8A-8C illustrate an intra-corporeal motor, a first gearbox reducing the shaft speed, a first rotor, a bevel gearbox achieving a contra-rotation from the first rotor, and then the second rotor. The bevel gearbox achieving a contra-rotation from the first rotor is illustrated in FIGS. 8A and 8C.

[0315] In some embodiments, power may be delivered to blades by a miniature electric motor (or motors). The motor, controller, and power supply may be extra-corporeal, as described elsewhere herein. The motor may be extra-corporeal and catheters may serve as drive shafts. The motor may be intra-corporeal. The motor may be located in the hub of turbomachines. The catheter in the installed and operating condition may be an electric cable delivering power from outside the body to the motor location in the aorta. The motor may be intra-corporeal with the controller and power supply being located extra-corporeally.

[0316] In some embodiments, a gearing mechanism may be needed between the motor and the rotating impeller or propeller. The gearing mechanism may be located next to the motor. The gearing mechanism may be located next to the one or more impellers. The gearing mechanism may be intra-corporeal or extra-corporeal. In some embodiments, the motor, gearing mechanism, and propeller/impeller are all intra-corporeal, and only the electric cable goes through the rotor. In some embodiments, one or more of the motor, gearing mechanism and propeller/impeller are intra-corporeal. In some embodiments, one or more of the motor, gearing mechanism and propeller/impeller are extra-corporeal.

[0317] One or more epicyclic gears (also known as planetary gears) may be used to achieve contra-rotation between the two rotors. Epicyclic gears have four main elements: a sun; planets; a planet carrier; and a ring. One of three components is held stationary: the planet carrier and planets; or the ring; or rarely the sun. Depending on which component is held stationary different gear ratios are achieved, and concurrently the output shaft may be co-rotating or contra-rotating from the input shaft to the gearbox. The epicyclic gearbox or boxes may be intra- or extra-corporeal.

[0318] FIG. 9A-9D illustrate a configuration with two gearboxes or gearing mechanisms 554. The first gear 554 and the motor 770 are within a sealed capsule. The second gear 554 is located between the rotors 510. The ring of the second gear is connected to the second rotor 510. FIG. 9A illustrates the two gearboxes. FIG. 9B illustrates the external view of the MCS device 500. FIGS. 9C and 9D illustrate the location of the two gear boxes within the device. This is one example of several arrangements of planetary gearboxes, other configurations are contemplated. The planetary gearboxes achieve contra-rotation. The MCS device comprises an intra-corporeal motor with two planetary gearboxes in series. The motor shaft is driving the sun of the first gearbox. The ring is stationary. The planet carrier is the output shaft for the first rotor and is connected to the sun of the second gearbox. The planets of the second gearbox are stationary and connected to the front stationary hub. The rotating ring of the second gearbox is the output. In this arrangement, the first rotor is contra-rotating from the motor shaft. In this arrangement, the second rotor is co-rotating with the rotor shaft. The size of the gear teeth can be used to modify the gear ratios as needed. The cage may be supported by the stationary motor. FIG. 9A-9D illustrate gear 1 and motor inside the sealed capsule and gear 2 with the ring connected to the second rotor. While the motor 700 is illustrated as having a 5 W (watt) power, other configurations are contemplated, e.g., 1 W, 2 W, 5 W, 10 W, 15 W, 20 W, 25 W, 30 W, or any range of the foregoing values.

[0319] FIG. 9A-9D illustrate an intra-corporeal motor with two epicyclic gearboxes in series achieving contra-rotation of two rotors. The input to the gearboxes is via sun gears, both driven by one center shaft. For instance, the downstream impeller may be driven by the planet carrier of the downstream epicyclic gearbox (e.g., ring fixed), and the upstream impeller may be driven by the ring of the upstream epicyclic gearbox (e.g., planet carrier fixed to nose cone, and via struts to stationary motor casing) to achieve contra rotation. The gear ratios can be adjusted by the diameters of their internal components to achieve exact contra rotation, i.e. the rpm of the two rotors is equal and opposite. In some embodiments, the diameters of internal gear components can be used to make the rpm of the downstream rotor higher or lower than the rpm of the upstream rotor, to accommodate contra-rotation at different impeller rpm, for optimal flow dynamics, or for balancing reasons.

[0320] FIG. 10 illustrates another configuration with two gearboxes 554. The rotors are omitted from the figures. The cage 600 is shown. The first gear G1 and the motor are within a sealed capsule. The ring is fixed with the first gear. In some embodiments, the first gear will operate the first rotor. In some embodiments, the second gear G2 is located between the rotors. The planets are fixed with the second gear. The cage may be supported by the stationary ring of the first gearbox and by the stationary hub. FIG. 10 illustrates G1 wherein the ring is fixed and G2 wherein the planets are fixed.

[0321] In some embodiments, in a contra-rotating configuration, there may be one motor with a differential-type gearing device. In some embodiments, bevel gears are provided. The bevel gears may provide contra-rotation to two shafts from one motor. This gearing may be intra-corporeal or extra-corporeal. If in this arrangement the motor is extracorporeal, then there may be one shaft from the motor to the intra-corporeal gearing. In this arrangement, there can be two contra-rotating shafts on the outlet of the bevel gearing, at the same axial end of the bevel gear, or in the opposite ends of the bevel gear. In some embodiments, the bevel gearing may be extra-corporeal, located next to the extra-corporeal motor. In this arrangement, two concentric shafts may be placed along the blood vessel to the contra-rotating impellers. Other configurations of intra-corporeal and extra-corporeal gearing mechanisms are contemplated.

[0322] In some embodiments, intra-corporeal motors may be configured tail-to-tail. In some embodiments, intra-corporeal motors may be configured head-to-tail. In some embodiments, intra-corporeal motors may be arranged in the axial direction. In some embodiments, intra-corporeal motors may be configured to articulate for installation. The intra-corporeal motors may be articulated, for example, by being located in an articulating sleeve.

[0323] In embodiments comprising one or more intra-corporeal motors in one or more turbomachine hubs, the electric cables may be installed around the perimeter of the cage or anchoring mechanism 600. In some embodiments, the electric cables may be installed along the hub of the device.

[0324] FIG. 10 is one example of several arrangements of epicyclic (planetary) gearboxes used to achieve contra-rotation, which comprises an intra-corporeal motor with two epicyclic (planetary) gearboxes in series to achieve contra-rotation. The motor shaft is driving the sun of the first planetary gearbox. The ring is stationary. The planet carrier is the output shaft for the first rotor, and is connected to the sun of the second gearbox. The planets of the second gearbox are stationary, and connected to the front stationary hub. The rotating ring of the second gearbox is the output. In this arrangement the first rotor is contra-rotating from the motor shaft, and the second rotor is co-rotating with the rotor shaft. The size of gear teeth can be used to modify gear ratios as needed. In this example the cage is supported by the stationary motor or stationary ring of the first gearbox, and by the stationary hub, as shown in FIG. 10.

[0325] FIGS. 11A-11B illustrate an embodiment of the MCS device 500. In some embodiments, the MCS device 500 may comprise a nose propeller 570. The MCS device 500 may include foldable caging, forming a support structure 600. The MCS device 500 may include one or more hydrodynamic bearings 572. The MCS device 500 may include one or more blades 520. The MCS device 500 may include one or more gearboxes 554. The MCS device 500 may include a motor 700. The MCS device 500 may include a sealed capsule 550 for the motor 700. The MCS device 500 may include a cord 574 extending from the sealed capsule. The foldable cage 600 extends from the nose propeller and the sealed capsule. The nose propeller and the sealed capsule include hubs that allow the foldable cage 600 to connect thereto.

[0326] FIG. 12 illustrates an example of lubrication path 576. The lubrication path extends through the sealed capsule 550. The lubrication path extends through the gearboxes 554 G1, 554 G2. A biocompatible lubricant may be pumped through the motor 700 and/or gearbox or gearboxes 554. One example, in which the lubricant is diffused in the blood stream, is shown in the figures. The lubricant may be returned outside the body. FIG. 12 illustrates lubrication and/or cooling with an intra-corporeal motor. With suitable choice of components, the device may run unlubricated or dry. In some embodiments, a biocompatible fluid may be pumped to lubricate and/or cool the components.

[0327] FIG. 13 illustrates spiral grooves 578. The pump-out spiral grooves may improve the wash-out flow in the critical regions. Spiral grooves may be used between rotating and stationary elements in the pump head to remove stagnant blood flow between rotating and stationary components. FIG. 13 illustrates pump-out spiral grooves to improve the wash-out flow in the critical regions.

[0328] FIGS. 14A-14C illustrate the opening of blades within an hour glass support 600. FIG. 14A illustrates full opening in a larger aorta. The hour glass support 600 is opened to the maximum inner diameter of the aorta. The outer diameter may be approximately 19 mm. The edges of the struts extend to the maximum aortic diameter. The blades form an angle of 90 degrees with the longitudinal axis of the MCS device 500. FIG. 14B illustrates partial opening of the hour glass support 600 in a smaller aorta. The hour glass support 600 is opened to the minimum inner diameter of the aorta. The blades form an angle of 90 degrees with the longitudinal axis of the MCS device 500.

[0329] The tip diameter of the propeller is approximately the same in FIG. 14A and FIG. 14B. The MCS device 500 may be configured to maintain a substantially constant gap size between the blade tips and the hour glass support 600 regardless of size of the aorta. In some embodiments, the MCS device 500 can include an anchoring mechanism designed to open in an hour glass like fashion. The impellers or propellers of the MCS device 500 may possess a fixed tip diameter relative to the hour glass support in the open position. The diameter of the fixed diameter propellers or impellers may be set, for example, at approximately 10 mm, 12 mm, 14 mm, 16 mm, 18 mm, 20 mm, 22 mm, 24 mm, 26 mm, 28 mm, 30 mm, 32 mm, between 10 mm and 20 mm, between 20 mm and 30 mm, less than 30 mm, less than 22 mm, less than 20 mm, less than 18 mm, more than 10 mm, more than 14 mm, more than 16 mm, or any range including two of the foregoing values.

[0330] MCS devices may include a tip-diameter dimension. The interior diameter of the aorta at the implantation location varies from patient to patient, for instance, between approximately 20 mm and 32 mm. This varying dimension may present a series of problems, as there is generally a desire to limit the gap between the propeller or impeller tip and the surrounding device or blood vessel structure. Optimal gaps, balancing requirements between hydraulic efficiency and hemolysis, may be between approximately 0.2 and 2 mm, e.g., 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 2 mm, or any range including two of the foregoing values. Optimal gaps, balancing requirements between efficiency and hemolysis, are between 0.2 and 1 mm, e.g., 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, or any range including two of the foregoing values. For example, in some embodiments, the preferred or nominal gap size may be approximately 0.5 mm. In some embodiments, the nominal gap size may be approximately 0.0 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, less than 0.7 mm, less than 0.5 mm, less than 0.3 mm, or any range including two of the foregoing values.

[0331] FIG. 14C illustrates the collapsed configuration. The top struts and the bottom struts are stretched axially. In some embodiments, the blades of the impellers have flexible connections to the corresponding impeller hubs. The flexible connections may facilitate insertion and removal with folded blades. The flexible connections may facilitate operation when the blades are unfolded. In some embodiments, the MCS device 500 may include one or more foldable propellers and/or impellers. The foldable impellers may be inserted collapsed against the hub of the device, and then opened at the desired aortic location. The tip diameter of the impeller or propeller can be maintained at a constant gap due to the constant diameter of a middle portion of the hour glass. The hour glass design may keep the turbomachine tip-to-cage gap at optimum levels as described herein.

[0332] In some embodiments, the blades may be inserted in a collapsed state. The blades may be spring-loaded and ready to expand upon removal of the sleeves. Once expanded, the centrifugal action of rotation may keep the blades in an open configuration. In some embodiments, the blades may be locked in position. In some embodiments, the blades are locked from the hub side.

[0333] The hour glass support 600 may be implanted first and separately from the MCS device 500. The hour glass support 600 may be implanted alone. The hour glass support 600 may be implanted like a stent cage. The hour glass support 600 may have a balloon or space occupying feature to ensure the central lumen matches the diameter of the impeller. The hour glass support 600 may have a balloon or space occupying feature to ensure that there is not excessive gap between tip of impeller blades and wall of vessel/or wall of hour glass support 600. If the hour glass support 600 is delivered independently, the MCS device 500 may have pre-swirlers and post-swirlers. In some embodiments, the pre-swirlers and post-swirlers are self-expanding or mechanically expanded disks. In some embodiments, the pre-swirlers and post-swirlers may centralize the impeller and prevent collision with vessel wall. In some embodiments, the pre-swirlers and post-swirlers may be collapsible if the device is to be removed.

[0334] In some embodiments, the hour glass support 600 is an adjustable size device. In some embodiments, the hour glass support 600 accommodates variable sized blood vessels using adjustability. In some embodiments, the hour glass support 600 is available in a potential matrix of device sizes, from smaller to larger diameters. In some embodiments, there is the ability to select a device from a range of device sizes from smaller diameters to larger diameters. In some embodiments, the hour glass support 600 is available in a variety of diameter sizes in the fully open position to accommodate varying aorta sizes. For instance, each the hour glass support 600 may be designed to operate within a range of aortic sizes.

[0335] In some embodiments, the hour glass support 600 is an expandable member. The hour glass support 600 may include a cylindrical-sleeve portion in which the impellers operate. The hour glass support 600 may include an open center to accommodate the open propeller or impeller. In some embodiments, the hour glass support 600 and the blades each have a fixed diameter such that the gap between the two can be fixed. In some embodiments, the hour glass support 600 includes top struts and bottom struts. The top struts and bottom struts can be used to adjust the size of the hour glass support 600 to the aortic diameter. The top struts and bottom struts can be varied to adjust for the aortic or blood vessel size. The top struts and bottom struts may be coupled to a stent like structure. The stent like structure can be an hour glass shape as shown in FIG. 14A or cylindrical as shown in FIG. 14B. The top struts and bottom struts may stretch the stent like structure toward the aortic diameter. The top struts and bottom struts may facilitate locating the hourglass cage axially. The structures of the struts may be shaped to open into 3D blades. The top struts and bottom struts may assist in directing the flow in the desired direction.

[0336] In some embodiments, the impellers are folded in an hourglass-shaped cage. The hourglass-shaped cage may form an inlet upstream of the first rotor. The inlet may be configured to accelerate the axial component of flow velocity. In some embodiments, the device includes a flow diffuser downstream of the second rotor.

[0337] The flow diffuser may be configured to decelerate the axial component of flow velocity. In some embodiments, the cage diameter between the inlet and the diffuser is constant. The inlet may taper inward toward the constant diameter. The flow diffuser may taper outward from the constant diameter. In some embodiments, the constant cage diameter between the inlet and the diffuser may be designed to make one size of rotor diameters fit anatomically different larger inside diameters of the blood vessel. In some embodiments, the constant cage diameter is selected to correspond to a single diameter rotor. In some embodiments, the constant cage diameter is selected based on the desired gap between the cage and the blades. As illustrated in FIGS. 14A and 14B, the constant cage diameter accommodates the same size blade and gap, regardless of the size of the inlet and flow diffuser. In some embodiment, the waist section near the middle of the support has a constant diameter, sized to accommodate an impeller of fixed diameter and thus a fixed gap between blade tips and inner diameter of waist section. In some embodiments, the gap between the impeller and diameter of the waist is fixed. The gap may be chosen to minimize blood trauma by friction in the blood while minimizing backflow across the impellers from the high pressure region to the low pressure region of the pump. In some embodiments, the pump rotors are axially secured by connecting members or struts to a surrounding cage. In some embodiments, the cage is secured to the perimeter of the surrounding blood vessel, so that the cage protects the inside perimeter of the blood vessel.

[0338] In some embodiment, the hour glass support 600 is made of shape memory alloy. In some embodiment, the hour glass support 600 is made of Nitinol or another shape memory material. In some embodiment, the hour glass support 600 is an open weave braided structure. In some embodiment, the hour glass support 600 is a tubular structure. In some embodiment, the hour glass stent structure may be covered with a biocompatible material. In some embodiments, the biocompatible material is configured to prevent blood flow through the biocompatible material.

[0339] The impellers and surrounding hour glass support 600 may be placed in the folded position. The impellers and surrounding hour glass support 600 may be inserted via a catheter in the aorta upstream of the kidneys. The impellers and surrounding hour glass support 600 may be positioned in the descending aorta or further upstream in the aorta, anywhere up to the aortic valve. Once the catheter is removed, the impellers and surrounding hour glass support 600 may spring into the unfolded position. After use, the impellers and surrounding hour glass support 600 may be removed via the reverse procedure by folding and capturing the impellers and surrounding hour glass support 600 into a catheter.

[0340] The contra-rotating impellers can provide various advantages. In some embodiments, two contra-rotating impellers result in maximum efficiency, minimum rotor rpm, and/or minimum hemolysis. In some embodiments, the downstream rotor reduces the swirling flow imparted by the upstream rotor in order to achieve near-axial downstream flow velocity, thus emulating the blood flow in healthy conditions of about one clockwise flow rotation downstream from aortic arch to renal arteries, while maximizing pumping efficiency, reducing impeller rpm, and reducing friction and turbulence from swirling flow downstream of the pump. In some embodiments, the pre-swirler and de-swirler struts optimize flow angles and turbomachinery efficiency. The structures of the struts may be shaped to open into 3D blades directing the flow in the desired direction

[0341] FIGS. 15A-15B schematically illustrate operating configurations of the hour glass support 600. FIG. 15A illustrates a collapsed configuration. FIG. 15B illustrates an expanded configuration. The hour glass support 600 may include section A, section B, and section C. In some embodiments, each section is expandable. In some embodiments, sections A and section C flare outward.

[0342] FIGS. 16A-16C schematically illustrate positions of the gearmotor. FIGS. 16A and 16B illustrate an extra-corporeal motor or gearmotor. FIG. 16A illustrates a gearmotor and the anatomical position of the device. FIG. 16B illustrates an extra-corporeal motor. The extra-corporeal motor can be integral with its own speed-reducing gearbox. The controller can be extra-corporeal. The monitoring algorithm can be extra-corporeal. The display can be extra-corporeal. The lubricant pump can be extra-corporeal. One or more of the motor, controller, monitoring algorithm, display and lubricant pump can be integrated in a housing or unitary device. FIG. 16C illustrates a configuration in which the motor or gearmotor is placed in the vicinity of the pump head. The motor can be an intra-corporeal motor. The location of the device is illustrated. The device may be used with either an external motor design or an internal motor design. The motor can be positioned in the descending aorta. The flexible drive shaft or cables may be external. The control and power to the motor can be external. FIG. 16C illustrates an internal motor and an external supply of power, control, monitoring and display. The display can be connected via a cable via the femoral artery. In some embodiments, one or more of the power, control, or monitoring functions is intracorporeal.

[0343] FIGS. 17A-17D schematically illustrate stages of delivery. FIG. 17A illustrates insertion. During insertion, the hour glass support 600 may be compressed. During insertion, the blades may be folded. The MCS device 500 can be positioned within a sheath or larger catheter. The MCS device 500 may be guided into position with a smaller guide catheter. The guide catheter may be connected to a portion of the MCS device 500. The hour glass support 600 may be a PTFE-coated stent-like frame.

[0344] FIG. 17B illustrates opening. During opening, the hour glass support 600 may be partially expanded. The upstream end can be laterally expanded. During opening, the blades may be partially unfolded. The upstream impeller can be unfolded. The downstream impeller can remain folded. The MCS device 500 can be uncovered at least partially from the sheath or larger catheter. The sheath can be retracted. The sheath can be moved downstream.

[0345] FIG. 17C illustrates pumping. During pumping, the hour glass support 600 may be fully expanded. The upstream and downstream end of the stent-like frame can be laterally expanded. The hour glass support 600 can be anchored. During pumping, the blades of the two or more impellers may be fully unfolded. The upstream and downstream impellers can be unfolded. The MCS device 500 can be uncovered from the sheath or larger catheter. The catheter can be fully retracted. The contra-rotating impellers can be rotated to pump blood. The hour glass support 600 can maintain a desired gap between the blade tips and the support.

[0346] FIG. 17D illustrates removal. During removal, the hour glass support 600 may be partially compressed. The downstream end can be laterally compressed. During removal, the blades may be partially folded. The downstream impeller can be folded. The MCS device 500 can be covered at least partially from the catheter or larger catheter. The catheter can be advanced. The catheter can be moved upstream. The catheter can be reapplied. The motion of the catheter can compress the hour glass support 600. The motion of the catheter can fold the blades.

[0347] In some embodiments, the folding, hour glass support 600 can be designed such that one device fits all anatomic sizes. The pumping head of the MCS device 500 may be placed in an hour glass support 600 which has a relatively long waist section B. The hour glass support 600 may be made of memory-shape alloy so it can be collapsed or expanded. The hour glass support 600 may be covered by a biocompatible material so that blood does not flow through its sides. In some embodiments, the minimum internal diameter of the patient's aorta is 19-20 mm, and the maximum is 32 mm, though these exact dimensions may vary. Thus the internal diameter of the hour glass support 600 at the waist section B may be 19 mm, and the impeller diameters 18 mm, allowing for impeller tip to waist internal diameter gap of about 0.5 mm. The sections of the hourglass upstream and downstream of the impellers allow for the diameter variations in aorta from minimum of about 19 mm to a maximum size that can be 32 mm, or larger.

[0348] FIGS. 18A-18C schematically illustrate folding and unfolding of the blades and cage sections into the larger catheter. This concept can be used in both extra-corporeal and intra-corporeal motor embodiments described herein. In some embodiments, the folding and unfolding is better suited to the extra-corporeal motor. The distance between the upstream top of the drive shaft T to the contra-rotating gearbox G downstream is fixed. The hour glass support 600 comprises sections A, B and C. The hourglass shape of the hour glass support 600 has memory-shape alloy struts T.S. upstream and bottom struts B.S. downstream. In some embodiments, the struts at their hubs may have bearings, such as journal bearings. The downstream bearing may be integral to the gearbox, blood lubricated, or lubricated via biocompatible lubricant. Separately, the upstream bearing at the hub of top struts T.S. may blood lubricated, or with biocompatible lubricant.

[0349] In FIGS. 18A-18C, the top T and the bottom gearbox G are at the same positions. The hour glass support 600 is divided in three sections. Section B may be larger than the distance between the blades to accommodate different openings from maximum to minimum aorta inner diameter. In some embodiments, the hour glass support 600 forms a Nitinol frame. In some embodiments, struts attached to the hour glass support 600. At the center of the struts, the struts can carry journal bearings. In the widest aortic inner diameter, the bottom struts B.S. already set for insertion in catheter. If aortic inner diameter is smaller, than bottom struts B.S. are in an even better position to enter into catheter. Advantages include that there can be the same gap between the one or more rotors and the section B. Advantages include that there can be the same length between the tip T and the gearbox G. Advantages include that the segments are already positioned for insertion to catheter or sheath for blade folding and removal.

[0350] FIGS. 19A-19C schematically illustrate an extra-corporeal motor and associated gearbox for the pumping head. FIG. 19A is a perspective view and FIGS. 19B-19C are side views. The gearbox achieving contra-rotation may be upstream of the rotors, between the rotors, or downstream of the rotors. In FIGS. 19A-19C, the gearbox is downstream of the two rotors. The blades may be folded upstream or downstream. In FIGS. 19A-19C, the upstream folding configuration is illustrated. All dimensions are for illustration purposes only, and exact dimensions will vary, including that of the overall catheter. The gearbox is connected to an external motor. The gearbox can have a larger diameter than the shaft connected to the rotor. The peripheral shaft can be connected to one of the rotors (Rotor 2) and the core shaft can be connected to another rotor (Rotor 1). The support 600 is illustrated in FIG. 19C. The inner diameter of the support can be larger than the diameter of the rotors when folded.

[0351] FIGS. 20A-20D illustrates the rotation of a peripheral shaft relative to the core shaft. The peripheral or key shaft may rotate in an equal and opposite direction to the core or hexagonal shaft. Two epicyclic gearboxes in series, like those used in the intra-corporeal motor embodiment described herein, may be used to achieve contra-rotation. In some embodiments, the gearboxes produce unequal impeller rpm. FIG. 20A illustrates the drive shaft, the gearing system, and the two rotors in a perspective view. FIG. 20B illustrates the gearing system. The drive power shaft extends from a first end of the gearing system. The core shaft and the peripheral shaft extend from the second end of the gearing system. The core shaft can have a first cross-sectional configuration and the peripheral shaft can have a second cross-sectional configuration, different than the first cross-sectional configuration. The core shaft can have a hexagonal configuration and the peripheral shaft can have a keyed configuration. FIG. 20B illustrates the gearing system with the casing removed. The two sun gears (Sun 1, Sun 2) are illustrated. The planet gears (Planet 1, Planet 2) are also illustrated. Rotation of the first sun gear (Sun 1) by the drive shaft causes contra-rotation of the second sun gear (Sun 2). The gear ratio can produce equal or unequal rpm. FIG. 20D illustrates three cross-sectional views of the rotation of the gear box. In section A-A, rotation of the Sun 1 causes rotation of Planet 1. In section B-B, rotation of the Planet 1 causes rotation of Planet 2. In section C-C, rotation of the Planet 2 causes rotation of Sun 2. In section A-A, rotation of the Sun 1 (clockwise) causes contra-rotation of Planet 1 (counterclockwise). In section B-B, rotation of the Planet 1 (counterclockwise) causes contra-rotation of Planet 2 (clockwise). In section C-C, rotation of the Planet 2 (clockwise). causes contra-rotation of Sun 2 (counterclockwise). FIG. 20D illustrates contra-rotation between Sun 1 and Sun 2. FIG. 20E illustrates another embodiment of an epicyclic gearbox.

[0352] FIGS. 21A-21D illustrate lubrication and/or cooling with an extra-corporeal motor. With suitable choice of components, the device may run unlubricated. In some embodiments, a biocompatible fluid may be pumped to lubricate the components. In some embodiments, a biocompatible fluid may be pumped to cool the components. FIG. 21A illustrate the sealed journal bearings of the gearbox. FIG. 21A also illustrates the clearance between the peripheral shaft and the core shaft. FIG. 21B is another view. FIG. 21C illustrates the active lubricant passing through the device. The lubricant travels through the drive shaft and sleeve, through the gearing, and through the clearance. FIG. 21D illustrates the active lubricant passing through the device. The lubricant travels through the drive shaft and sleeve, through the gearing, and between the rotors. The rotor (Rotor 2) can allow the lubricant to pass through.

[0353] FIGS. 22A-22C illustrate bearings. The bearings may be any type of bearings. In some embodiments, the bearings are journal bearings. FIG. 22A illustrates the shaft, the gearing system, and the rotors (Rotor 1, Rotor 2). FIG. 22B illustrates the shafts. The drive shaft may be circular shaft. The bearing may be coupled to the circular shaft. The peripheral shaft may be keyed. The core shaft may be hexagonal. The device may include a circular tip. The bearing may be coupled to the circular tip. FIG. 22C illustrates the rotors. The rotor (Rotor 2) may include a keyed cut. The keyed cut may couple with the keyed shaft. The rotor (Rotor 1) may include a hexagonal cut. The hexagonal cut may couple with the hexagon shaft. The core shaft, the peripheral shaft, and the rotors may have any configuration to allow the components to couple and transmit rotation and/or torque.

[0354] FIGS. 23A-23B illustrate embodiments of bending blades. The blades may be connected to the hub with thin segments of memory-shape alloy. In some embodiments, the memory-shape alloy is Nitinol. The memory-shape alloy can bend to insert in the catheter sheath for insertion, deploy and spring in the open position for operation, and then bend again for folding, recovery and removal. In some embodiments, the segment of the connecting part is made of appropriate shape to be fully inserted and not protrude out of the surface of the 3-dimensional blade. FIG. 23A illustrates a top view of the blade. The memory-shape alloy can extend along a portion of the length of the blade or the entire blade. FIG. 23B illustrates an embodiment of an extruded blade shape. The blade may have a twist along its span for fluid dynamic reasons. The connecting shape can be referred to as the dagger. The dagger is affixed to the hub at one end, and to the blade at the other.

[0355] FIGS. 24A-24F illustrate blade deflection upstream and downstream. As the dagger is flexible, during operation the daggers and attached blades may be deflected upwards by the hydrodynamic force. For that reason the daggers in the relaxed position may be deflected downstream, for example by 15 degrees, in order to bring the blades to a horizontal position during normal operation. FIG. 24A illustrates the hydrodynamic force and the centrifugal force when the rotor is rotating. FIG. 24B illustrates the blades folded. The daggers are folded enabling the blades to fold. The blades are folded approximately 90 degrees. FIG. 24C illustrates the blades in relaxed position. This position may be the position of the blades before rotation. The blades may be deflected downstream, for example by 15 degrees. Other angles are contemplated, for example 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, or any range of the foregoing values. FIG. 24D illustrates another view of the blades in the relaxed position. The Nitinol struts are manufactures at about 15 degrees downward in the unrestrained original configuration. FIG. 24E illustrates the strut and the blade. The blade extends downward at approximately a 15 degree angle. The blade and the strut can be formed of different materials. The strut can be formed of a shape memory material such as Nitinol and the blade can be formed of a more rigid material such as stainless steel. The strut can bend to allow folding of the blade. FIG. 24F illustrates an embodiment of a Nitinol structure for the twisted blade. The structure can include a bending flat ribbon. The ribbon can allow the blade to fold. The structure can include a twisted structure to be embedded in the twisted blade body. The twisted structure can follow the bend of the blade such that the twisted structure is completely embedded. The ribbon can protrude from the blade.

[0356] FIGS. 25A-25E illustrate blade folding. FIGS. 25A-25E illustrate approximate dimensions with blades folding upstream or downstream. The daggers may be affixed at an angle to the hub are shown, or may be affixed orthogonal to the hub. FIG. 25A illustrates the blade with an orthogonal dagger. FIG. 25B illustrates another view of FIG. 25A. FIG. 25C illustrates the blades folded upwards. FIG. 25D illustrates the blades folded downwards. FIG. 25E illustrates top and bottom views of the folded blades. In some embodiments, the blades can only fold in one direction, e.g., either upward or downward. In some embodiments, the blades can fold in both directions.

[0357] FIGS. 26A-26F illustrate blade construction. The daggers may be constructed in layers of Nitinol or other materials. The daggers may be constructed of layers of selected shapes. The layers may have different cross-sections to accommodate requirements of shear stress in bending, folding and unfolding. The layers may have different cross-sections to accommodate requirements of normal stress in joints to the blade and hub. The layers may have different cross-sections to accommodate requirements of selective weakening for bending. The layers may have different cross-sections to accommodate requirements of shape constraints for insertion of the 3D blades. The daggers may be two-dimensional, orthogonal to the hub axis, or twisted. FIG. 26A illustrates an embodiment of the layer construction. FIG. 26A illustrates four daggers that can be connected to four blades. The central opening can couple to a rotor. FIG. 26B illustrates the hubs of the rotors. Rotor 1 may include a hexagonal cut and Rotor 2 may include a keyed cut. FIG. 26C illustrates the dagger coupled to a rotor. The dagger may include highly twisted Nitinol ribbons to be accommodated into the blades. The blades can be formed onto the dagger in any manner known in the art or the dagger can be inserted into the blades. FIG. 26D illustrates the two rotors with the blade assemblies. FIG. 26E illustrates the inclined blades. The dagger can position the blades at a tilt. In some embodiments, the blades are positioned at a 15 degree inclined angle.

[0358] The case of axial impellers in a cylindrical flow passage is shown in FIG. 27. FIG. 27 shows an example embodiment of impellers. A single impeller 800 (left side) imparts a vortex pattern 802 downstream of the impeller. The vortex pattern 802 continues down the cylindrical flow passage. An impeller system 804 which incorporates a second contra-rotating impeller 806 (right side) substantially removes the vortex pattern 808 that is generated downstream of the first impeller 810. The contra-rotating impeller 806 establishes a substantially axial flow 812. Flow 812 is primarily in the axial direction, with little or no rotation, thus maximizing pressure rise and efficiency.

[0359] The results can be similar for the case of helical screw impellers, in some embodiments. A single helical screw impeller may tend to generate a flow with a substantial vortex pattern which can continue downstream of the impeller. A helical screw impeller with a contra-rotating impeller can correct this flow resulting in a primarily axial flow.

[0360] FIGS. 28A-28C show two dimensional velocity diagrams related to the impeller system 804. The nomenclature used by Wilson and Korakianitis (2014) is used here. C: absolute velocity vectors; CU: tangential component of absolute velocity vector; U: rotor tangential velocity vectors: W: relative velocity vectors; 1: inlet to upstream rotor; 2: outlet of upstream rotor; 3: inlet to downstream rotor; 4: outlet of downstream rotor.

[0361] The velocity diagrams show axial inflow and outflow velocity vectors C1 and C4, in cases where the rotors are rotating at equal revolutions per minute (U1=U2), or at not equal revolutions per minute (U1 not equal to U2).

[0362] FIG. 29 illustrates the case where the absolute velocity C4 has a tangential component of velocity CU4 creating a relatively weak vortex flow pattern downstream of the impeller. The weak downstream vortex flow emulates healthy physiological conditions. This concept is further explained below.

[0363] FIG. 30 depicts an example embodiment of a blade 814. In this embodiment, the velocity diagram and blade angles vary from hub 816 to tip 818 to meet radial equilibrium and de Haller ratio considerations. In some embodiments, the 2D cross-section of the blade 814 may remain invariant from hub to tip.

[0364] An example vortex flow pattern with tip diameter of, for example, between about 18-20 mm is shown in FIG. 31. The hub to tip distribution of flow angles and subsequent blade angles of an impeller can be designed to provide a downstream velocity component C4 that is slightly off the axial direction, such that velocity component C4 includes a small tangential component of velocity. The small tangential component of velocity may provide near healthy physiological flow. To exhibit a near healthy physiological flow, C4 may exhibit 1-3 rotations of the blood in about 30 cm length of descending aorta and exhibit an internal helical flow structure, as illustrated in FIG. 31. While FIG. 31 shows a particular example of a vortex flow pattern approximating a healthy physiological flow, many different vortex flow patterns may approximate a healthy physiological flow. Such vortex flow patterns may have a different number of turns in 30 cm at the tip, near the tip, near the mean, and near the hub. Correspondingly, while FIG. 31 shows a particular distribution of radius at the tip, near the tip, near the mean, and near the hub for a vortex flow pattern which approximates a healthy physiological flow, different dimensions may also correspond to a vortex flow approximating a healthy physiological flow. In some embodiments, there may be 3 helical patterns at the tip, 2 in the mid-section of the blades, and 0.5 in the hub section of the blades, all in the same length of aorta, e.g., a different number of helix hub to tip of blades.

[0365] FIG. 32 depicts an example embodiment for an upstream rotor 828. The cross-sections A, B, C, and D are shown to the right of the rotor 828. While the depicted geometry distribution may be typical, other geometry distributions may be used. In some embodiments, the chord length variation from hub to tip may be increasing. In some embodiments, the chord length variation from hub to tip may be decreasing. In some embodiments, the chord length from hub to tip may be constant. In FIG. 32 the cord length is shown as increasing from the hub to the tip. Similarly, the leading edge may be radially curved as shown in FIG. 32. The leading edge can follow any curve.

[0366] FIG. 33 depicts an example embodiment for a downstream rotor 838. The cross-sections A, B, C, and D are shown to the right of the rotor 838. While the depicted geometry distribution may be typical, other geometry distributions may be used. In some embodiments, the chord length variation from hub to tip may be increasing. In some embodiments, the chord length variation from hub to tip may be decreasing. In some embodiments, the chord length from hub to tip may be constant. In FIG. 34 the cord length is shown as increasing from the hub to the tip. Similarly, the leading edge may be radially curved or can follow any curve.

[0367] The depicted downstream rotor 838 corresponds to the depicted upstream rotor 828. The depicted downstream rotor 838 is not symmetric to the depicted upstream rotor 838. This difference is related to the relative flow vectors W1 to W4 in the velocity diagrams shown in FIGS. 28A, 28B, 28C, and 16 being not-symmetric).

[0368] In some embodiments, the flow diagrams and blade shapes may be chosen so that the upstream rotor 828 and downstream rotor 838 provide equal pressure rise. In some embodiments the upstream rotor 828 may be designed to provide higher, pressure rise than the downstream rotor 838. In some embodiments the upstream rotor 828 may be designed to provide lower pressure rise than the downstream rotor 838.

[0369] FIGS. 34, 35, and 36 depict an embodiment of a uni-rotor design. This design includes at least one blade row 848. This blade row 848 may be an impeller. The blade row 848 may be configured to fold inside a collapsible impeller cage 850. The collapsible cage inlet 852 and outlet 854 are shown secured in the inner diameter of the blood vessel 856. In some embodiments there is a pre-swirler membrane 858 upstream of the blade row 848. In some embodiments there is a de-swirler membrane 860 downstream of the blade row 848. The pre-swirler 858 and de-swirler 860 membrane carry the requisite forces by their securement between the axle 862 of the blade row and the collapsible impeller cage 852. The pre-swirler 858 and de-swirler 860 membranes may have a skeleton of memory alloy lattice covered by a biocompatible material like PTFE or may be made by thin sheets of 2D printed memory-shaped material, metal or plastic, like nitinol. In some embodiments, a membrane can include a flexible fine netting of memory-shaped material, metal or plastic, like nitinol used as a cover over the blade frame. In some embodiments, the membrane can include a biocompatible material netting. The nettings can be porous and flexible, but no blood can go through in some cases. In some embodiments there is a flexible shaft 862 carrying the rotational motion to the impeller 848 from an extra-corporeal motor. The device 846 may be collapsed into a catheter for removal and implantation as further described elsewhere herein.

[0370] FIG. 37 shows an example embodiment with contra-rotating rotors 872 and 874. These rotors may be driven by two concentric contra-rotating shafts. In one scenario the blades are collapsible and are installed in a collapsible hourglass cage frame. The frame can, in turn be installed in a descending aorta. The installation is further described later and can be similar to the installation process used for a uni-rotor design such as described in connection with the device 846.

[0371] FIGS. 38A, 38B, 39A, and 39B depict fluid flow in cases where the shaft 884 diameter is small. In these cases, the hydrodynamic blade loading near the hub becomes too high and the flow locally separates. The local separation induces recirculation flow regions 886 near the hub 888. Similar flow recirculation regions may occur near the hubs of foldable blades. The recirculation regions 886 reduce the efficiency of the impeller system. These recirculation flow regions can be removed by increasing device rpm. Alternatively, the recirculation regions can be removed with the addition of a second set of smaller-diameter impellers downstream of the main impellers. These smaller impellers may be axial impellers, or helical screws.

[0372] FIGS. 40A and 40B depict an embodiment of a contra-rotating impeller system 898 with first blades 890 and second blades 892. The blades can eliminate the separation region near the hub. The blades can function the same as the helical screws, described herein.

[0373] The blades 890 and 892 can be a second set of rotor blades with a tip diameter less than the tip diameter of the main blades 894 and 896. The blades 890 and 892 may be placed immediately downstream of the main contra rotating rotors to improve flow conditions near the hub. This arrangement helps to prevent back flow and separated flow regions.

[0374] The blades 890 and 892 may, in some embodiments be at the same azimuthal position as the main blades 894 and 896 located upstream. In some embodiments, the blades 890 and 892 may have a different azimuthal position then the main blades 894 and 896. As shown in FIG. 40A, the blade count on the support blades 890 and 892 may be the same as the main blades 894 and 896. As shown in FIG. 40B, the blade count on the blades 890 and 892 may be different than the main blades 894 and 896. In some embodiments the blades 890 may have the same blade count at the support blade 892. In other embodiments the blade count of blades 890 may vary from the blade count of support blade 892.

[0375] FIG. 41, 42, 43 depict an alternative arrangement. In FIG. 41 the depicted arrangement includes a helical secondary blade 906 positioned downstream of one main impeller 908. FIG. 42 depicts a helical secondary blade 906 positioned between two contra-rotating impellers 910 and 12. FIG. 43 depicts a helical secondary blade 906 located between contra-rotating impellers 910 and 912, it further depicts a second shorter helical secondary blade 914 locater downstream of the impeller 912. All of these arrangements can potentially function to provide a better flow condition near the hub, thereby reducing or preventing backflow and separated flow regions. The arrangement and geometry of the helical blades in absolute, and relative terms can vary. The revolution, pitch and number of the helical blades can all vary.

[0376] FIGS. 44A and 44B depict different arrangements with a combined helical blade 906, 914 and contra-rotating impellers 910, 912. The number of blades, on the helical screws 906, 914, can vary. The revolution and pitch characteristics of the helical screws 906, 914 may also vary. The helical screw 906 located between the contra-rotating blades, and the helical screw 914 located after the contra-rotating blades may have different helical screw characteristics including the pitch, revolution, step, and number.

[0377] As shown is FIG. 45, in some embodiments smaller helical screw 906 diameter, allows upstream folding of the blades. In this example embodiment the helical screw 906 and helical screw 914 have different diameters.

[0378] FIG. 46 and FIG. 47 depict example embodiments of a epicyclic gearboxe system 924 having a sun gear 926, which is surrounded by planet gears 928. The planet gears, or pinions, 928 can be connected to each other via a planetary carrier 930. In the depicted embodiment, the ring gear 932 surrounds the planet gears 928. In the depicted embodiment, the planetary carrier 930 fixes the locations of the planet gears 928 relative to each other. In the depicted embodiment, the internal teeth of the ring gear 932 mesh with the teeth on the planet gears 928. In the depicted embodiment, the teeth on the sun gear 926 mesh with the teeth on the planet gears 928.

[0379] During operation, when the sun gear 926 is rotated clockwise and the planetary carrier 930 is held stationary, the planet gears 928 move counterclockwise. The center of the planetary gears 928 do not move relative to the sun gear 926. In this configuration, the ring gear 932 turns clockwise. This mode of operation is depicted on the right side of FIG. 47. This configuration is sometime referred to as a star arrangement 934. The input and output shafts of the star arrangement 934 rotate in the same direction. This type of rotation can be referred to as co-rotation. In some embodiments, the input shaft may be connected to the sun gear 926. In some embodiments, the input shaft may be connected to the ring gear 932. In some embodiments, the output shaft may be connected to the sun gear 926. In some embodiments, the output shaft may be connected to the ring gear 932.

[0380] A second configuration is shown on the left side of FIG. 47. When the sun gear 926 is rotated clockwise and the ring gear 932 is held stationary, the planet gears 928 spin in counterclockwise around the sun gear 926. The centers of the planet gears 928 rotate around the sun gear 926. This motion results in a force turning the planet carrier 930 clockwise. This configuration is called the planetary arrangement 936. In the planetary arrangement and the input and output shafts rotate in opposite directions. This type of rotation is sometimes called contra-rotation. In some embodiments, the input shaft may be connected to the sun gear 926. In some embodiments, the input shaft may be connected to the planet carrier 930. In some embodiments, the output shaft may be connected to the sun gear 926. In some embodiments, the output shaft may be connected to the planet carrier 930.

[0381] There are many other simpler and more complex arrangements of epicyclic gearboxes, some of which are described elsewhere herein. Epicyclic gearboxes can achieve higher gear ratios than simpler gears of the same size and weight. Variants of the epicyclic gearbox have been used in many applications. Applications employing epicyclic gearboxes include automotive differentials, marine gears, clockmaking, aerospace applications, gearing the output rpm of electric motors, etc. To the inventors' knowledge, epicyclic gearboxes have not been used to vary the rpm and direction of rotation of heart-assist pump impellers, nor been applied in heart assist pumps of any type.

[0382] Epicyclic gears are advantageous in the context of heart-assist pumps to achieve contra-rotation of upstream and downstream impellers. Some advantages of contra-rotating impellers can be described elsewhere herein.

[0383] FIG. 48 depicts various example embodiments of contra-rotating rotor systems. In some embodiments, the upstream rotor 946 and downstream rotor 948 could be contra-rotating at equal rpm. In some embodiments the upstream rotor 946 and downstream rotor 948 could be contra-rotating at unequal rpm. In an example embodiment, the contra-rotating rotors are installed in the waist section of a collapsible hourglass-shaped cage frame. This arrangement is further described elsewhere herein.

[0384] In some embodiments, the gears 950 may be upstream of rotors. In some embodiments, the gears 950 may between rotors. In some embodiments, the gears 950 may be downstream of rotors. In some embodiments, the gears 950 may be epicyclic gears. In some embodiments, gears 950 that are downstream of the rotors are intra-corporeal. In some embodiments, gears 950 that are downstream of the rotors are extra-corporeal. In some embodiments, the motor driving the gears G may be intra-corporeal. In some embodiments, the motor driving the gears G may be extra-corporeal. In some embodiments, gears 950 that are upstream of the rotors may be fixed to a caging. In some embodiments, gears 950 that are between the rotors may be fixed to struts 952. Struts 952 may be fixed to a caging. In some embodiments, gears 950 that are downstream of the rotors may be fixed to a housing of a flexible shaft.

[0385] FIG. 49 depicts an example embodiment of an impeller system 962, also known as a pump head 962. Depicted in the figure are an upstream rotor 946, downstream rotor 948. Rotors 946 and 948 are fixed to an hourglass shaped caging 964 via struts 966. Upstream of the two rotors in an internal gearing 968. Driving the rotors 946 and 948 is the flexible shaft 970. The flexible shaft 970 is connected to the intra-corporeal pump head 962. The flexible shaft 970 travels trans-corporeally to connect to extra-corporeal components. The extra-corporeal components include a gearhead 972 coupled to a motor 974. The motor 974 is functionally connected to a controller 976. In some embodiments, the internal gearing 968 may be an epicyclic gear. This embodiment may be an example of upstream gearing with an extra-corporeal motor.

[0386] FIG. 50 depicts an example embodiment of downstream gearing with an extra-corporeal motor. This figure shows an intra-corporeal pump head 986. This pump head is similar to the pump head 962 with a few differences. A main difference is that the gearing system 968 is downstream of the Rotors 946 and 948. The depiction of pump head 986 includes a bearing 988 positioned between the rotor 946 and the upstream struts 966.

[0387] FIGS. 51-54 depict example embodiments of intra-corporeal gearing and intra-corporeal motors.

[0388] FIG. 51 depicts a system 998 with a first gearbox G1 1004 located downstream of the rotors 946 and 948. In the depicted system 998, the motor 1000 is located adjacent to the gearbox G1 1004. In some embodiments, the motor is further downstream than the gearbox G1 1004. In system 998, a second gearbox, G2 1006 may be located between the rotors 946 and 948. As shown by the arrows in FIG. 51 the rotors are contra-rotating. The motor may be powered by the power supplied through the connector 1002.

[0389] FIG. 52 depicts a rendering of system 998. FIG. 52 shows the parts shown in FIG. 51 except the connector 1002 is not shown.

[0390] FIG. 53 depicts another example system. The depicted system 1003 is similar to system 998 but the figure shows additional detail for the gears 1004 and 1006. In this depicted embodiment, gear 1006 is an epicyclic gear with the ring 1008 fixed. The motion of the planetary carrier 1010 drives the rotor 946. In the depicted embodiment the gear 1004 is an epicyclic gear with the planets 1012 fixed. The motion of the ring 1014 drives the rotor 948.

[0391] FIG. 54 depicts a rendering of system 1003.

[0392] FIGS. 55, 56, 57A, and 57B depict a system 1024. In the depicted embodiment, the planetary carriers 1026 are stationary planet carriers. In some embodiments, the planetary carriers are fixed to the motor 1000 and upstream hub 1028.

[0393] In some embodiments, in a first stage 1030, the ring 1032 rotates in the opposite direction of the sun 1034 via a planet gear pair 1036 between the sun 1034 and ring 1032.

[0394] In some embodiments, in a second stage 1038, the ring 1040 rotates in the same direction of the sun gear 1042 via an inner planet gear pair 1044 and an outer planet gear pair 1046.

[0395] Some advantages of this arrangement is that it may allow both sun gear 1042 and sun gear 1034 to be driven by a single motor shaft 1046. The sun gears 1042 and 1034 can be rotated the same direction while achieving contra-rotation of the rotors 946 and 948. This arrangement may simplify the drive system, and could make the system more reliable in operation and less expensive in manufacture. The following arrangements may also offer these advantages.

[0396] FIG. 58 depicts system 1024 with caging 1048 enclosing various components. In some embodiments the caging may be folding caging. In some embodiments the caging may encompass various combinations of components.

[0397] FIG. 59 depicts a system 1058 that is similar to the system 1024 with various differences. In some embodiments of system 1058, a first stage 1060 is included. The first stage 1060 may include a ring R1 that is held stationary. The planets P1, drive the planetary carrier P1 carrier. The planetary carrier P1 carrier drive the rotor Rotor 1.

[0398] In some embodiments, a second stage 1070 is included. The second stage 1070 may include stationary planets P2. In some embodiment the planets P2 may be connected to the motor via the caging 1048. The second stage 1070 may also include ring R2. The ring R2 may drive the rotor Rotor 2.

[0399] In some embodiments, the first sun (S1) and the second sun (S2) are driven by the motor shaft 1046.

[0400] FIG. 60 depicts a system 1080 that can include any number of features similar to the system 1024 with various differences.

[0401] Referring now to the first stage 1082, in some embodiments of the planets P1 are stationary. In some embodiments the planets are connected directly to the motor 1000 to remain stationary. In some embodiments the ring R1 is the rotor Rotor 1 driver.

[0402] Referring to the second stage 1084, in some embodiments the ring R2 is held stationary. In some embodiments, the ring R2 is held stationary by connecting the ring R2 to the motor via the shafts of the planetary gears P1. In some embodiments, the planets P2 drive the planetary carrier P2 carrier. In some embodiments, the planetary carrier P2 carrier drives the rotor Rotor 2.

[0403] In some embodiments, the first sun (S1) and the second sun (S2) are driven by the motor shaft 1046.

[0404] FIG. 61 depicts a system 1090 that can include any number of features similar to the system 1024 with various differences. Referring now to the first stage 1092. In some embodiments the ring R1 is held stationary. In some embodiments, the ring R1 is held stationary by connecting the ring R1 to the caging 1048. In some embodiments, the ring R1 is held stationary by connecting the ring R1 to the motor 1000. In some embodiments, the sun S1 drivers the planets P1. In some embodiments, the planets P1 drive the planetary carrier P1 carrier. In some embodiments, the planetary carrier P1 carrier drives the rotor Rotor 1.

[0405] Referring now to the second stage 1094. In some embodiments, the sun S2 drives the the planetary carrier P1 carrier. In some embodiments, the sun S2 drives the planets P2. In some embodiments, the planets P2 are stationary. In some embodiments, the planets P2 are held stationary by fixing the planets P2 to the caging 1048. In some embodiments, the planets P2 drive the ring R2. In some embodiments, the ring R2 drives the rotor Rotor 2.

[0406] The speed of the rotor Rotor 2 can be lower than the speed of the rotor Rotor 1 if the suns S1 and S2 are equal diameter. To improve the speed of the rotor Rotor 2, the diameter of sun S2 may be larger than the diameter of sun S1.

[0407] FIG. 62 depicts a system 1100. System 1100 can include any number of features similar to system 1024 with various differences. In some embodiments, the motor 1000 is extracorporeal and the motor shaft 1046 is trans-corporeal.

[0408] FIG. 63 depicts a system 1110. System 1110 can include any number of features similar to system 1090 with various differences. In some embodiments, the motor 1000 is located extracorporeally. In some embodiments, stage 1092 is substantially located extracorporeally. Stage 1092 may be located extracorporeally, except a drive component 1112, linked to stage 1092, may be located proximally to the rotor Rotor 1 to drive rotor Rotor 1. The motor shaft 1046 may be positioned trans-corporeally.

[0409] FIGS. 64-66 depicts various alternative gear arrangements that can include any number of features similar to system 1110.

[0410] FIG. 64 depicts a system 1120. In some embodiments, the drive shaft 1046 directly drives the ring R2. The ring R2 may drive the rotor Rotor R1. The ring R2 may drive the planet gear pair P2. The ring R2 may drive both the planet gear pair P2 and the Rotor R1. The planets P2 may drive the sun S2. The sun S2 may be configured to have a large diameter region and a small diameter region. The planets P2 may interface with the small diameter region of the sun S2. The large diameter region of the sun S2 may drive the rotor Rotor 2.

[0411] FIG. 65 depicts a system 1130. In some embodiments, the drive shaft 1046 directly drives the sun gear S2. The sun S2 may be configured to have a large diameter region and a small diameter region. The small diameter region of the sun S2 may drive the planetary gears P2. The planet gears P2 may be stationary. The planet gears P2 may be held stationary by the cage 1048. The planetary gears P2 may drive the ring R2. The ring R2 may drive the rotor Rotor 1. The large diameter portion of the sun S2 may interface with and drive the rotor Rotor 2.

[0412] FIG. 66 depicts a system 1140. In some embodiments, the drive shaft 1046 drives the rotor Rotor 1. The drive portion 1142 of the rotor Rotor 1 may include a bevel gear 1144. The bevel gear 1144 may interface with two transition bevel gears 1146. The transition bevel gears 1146 may interface with a bevel gear 1148. The bevel gear 1148 may be included in a drive portion 1150. The drive portion 1150 may drive the rotor Rotor 2.

[0413] FIGS. 67 and 68 depicts various views of a system. The system can be an embodiment of the gearbox 1150 located downstream of the impellers. The gearbox 1150 may be intra-corporeal. The gearbox 1150 may be located immediately downstream of the impellers. The gearbox 1150 may be extra-corporeal. The gearbox 1150 may be placed near the extra-corporeal motor. In any case the gearbox 1150 may have one input drive shaft 1152 from the motor 1000 (not shown). The gearbox 1150 may have two contra-rotating output drive shafts. In some embodiments, one output shaft is a peripheral shaft 1154. In some embodiments, one output shaft is a core shaft 1156. The peripheral shaft 1154 and core shaft 1156 may be contra-rotating. The core shaft 1156 may be located within the peripheral shaft 1154 The example embodiment shows three planets 1158 engaging a sun 1160. In some embodiments, 2 or fewer planets 1158 may engage the sun 1160. In some embodiments, 4 or more planets 1158 may engage the sun 1160. The example embodiment shows three planets 1162 engaging a sun 1164. In some embodiments, 2 or fewer planets 1162 may engage the sun 1164. In some embodiments, 4 or more planets 1162 may engage the sun 1164.

[0414] In some embodiments, a step-up or step-down arrangement in the diameter of the planets 1162 engaging Sun 1164 at the location of section C-C, and a corresponding change in diameter of Sun 1164, allows for unequal rpm between the two contra-rotating output drive shafts. In some embodiments, the sun 1164 has a diameter equal to the diameter of the sun 1160. In some embodiments, the sun 1164 has a diameter larger than the diameter of the sun 1160. In some embodiments, the sun 1164 has a diameter smaller than the diameter of the sun 1160. In some embodiments, the planets 1158 have diameters equal to the diameters of the planets 1162. In some embodiments, the planets 1158 have diameters larger than the diameters of the planets 1162. In some embodiments, the planets 1158 have diameters smaller than the diameters of the planets 1162.

[0415] FIG. 69 depicts sample non-limiting dimensions for a gearbox 1150. These dimensions may correspond to an intra-corporeal gearbox 1150. The shown diameters are approximate. The lengths of the gear teeth may vary in order to carry the required torque for each impeller. If the gearbox is extra corporeal, then the diameters of components may be larger than shown.

[0416] FIGS. 70-72 depict a gearbox 1170 located extra-corporeally. The two coaxial shaft system 1176 travels transcorporeally from the gearbox outlet to the intra-corporeal impellers 1174. FIG. 72 depicts the shaft system 1176. In some embodiments, the shaft system includes an external sleeve 1178. The external sleeve 1178 may protect the patient from the rotating peripheral shaft 1180. The peripheral shaft 1180 may located within the external sleeve 1178. The peripheral shaft is hollow. The inner diameter of the peripheral shaft 1180 may be configured to surround an internal sleeve 1182 and the core shaft 1184. In some embodiments, the internal sleeve 1182 is used. The internal sleeve 1182 may be positioned between the core shaft 1184 and the peripheral shaft 1182. In some embodiments, no internal sleeve 1182 is used (and the shafts do not have any sleeve or lubricant between them, and only an external catheter outside the outer shaft to prevent contact of blood with the rotating shaft), such that dry lubrication occurs for the duration of use.

[0417] FIG. 73 depicts the shaft system 1176 interfacing with the impellers. FIG. 60 depicts a case of extracorporeal gearbox and concentric contra-rotating drive shafts. In some embodiment, the upstream impeller 946 is driven by the core shaft 1184. In some embodiments, the downstream impeller 948 is driven by the peripheral shaft 1180.

[0418] FIGS. 74-75 depict how lubricant 1186 is conveyed to the gearbox 1188 for intracorporeal gearboxes. If the motor and gearbox are extra-corporeal, they can be lubricated as is known in the art. For intracorporeal gearboxes, the lubricant 1186 may conveyed in an interstitial space 1191 disposed between the sleeve 1190 and the drive shaft 1192. In some embodiments, the lubricant will be a bio-compatible lubricant.

[0419] In some embodiments, an intracorporeal gearbox 1188 can be dry lubricated (unlubricated) for a device designed for temporary use. In some embodiments the intracorporeal gearbox 1188 may be actively lubricated with a biocompatible lubricant 1186 supplied at a high pressure. The high pressure may ensure that a small amount of lubricant is pumped in the blood stream, thus preventing the flow of blood in the device crevices.

[0420] FIG. 76 depicts an intracorporeal motor 1000. Lubrication for the intracorporeal motor 1000 can be provided in a manner described above in connection to the intracorporeal gearbox 1188. In some embodiments, the lubrication system may also provide lubrication for the motor, then the gearbox, then the contra-rotating shafts. Biocompatible lubricant under pressure at points 1, 2, 3, 4 etc. prevents blood from entering the device.

[0421] FIG. 77 depicts spiral grooves 1200. In some embodiments, spiral grooves 1200 may be disposed at interfaces involving rotating parts. In some embodiments, spiral grooves 1200 may be disposed at the rotating surfaces of the impellers 946 and 948. Spiral grooves may improve lubrication flow in critical regions. The spiral grooves can be used with any device described herein.

[0422] FIGS. 78 and 79 depict an example lubrication mechanism for with a system including an intra-corporeal gearbox 1202. In some embodiments, a lubricant 1186 is pressurized by the purge system 1204. The lubricant may then be conveyed through the purge tubing 1206 and between the sleeve 1190 and the drive shaft 1192 as previously described.

[0423] FIG. 80 depicts a normal distribution of inner descending aorta diameter. The red distribution is females over 60. The blue distribution is men over 60. These distributions inform the design of a one size fits all dimensions for the aorta. Based at least partially on this data, some embodiments may have a rotor tip diameter of about 18 mm and maximum collapsible frame diameter of about 33 mm.

[0424] FIGS. 81A-81C depicts a collapsible supporting hourglass frame 1210 made of shape memory alloy. FIG. 81A depicts the hourglass frame 1210 in a first, expanded, configuration. FIG. 81B depicts the hourglass frame 1210 in a second, elongated, configuration. The frame in FIG. 81B is both elongated and collapsed. FIG. 81C depicts the hourglass frame 1210 in the expanded configuration with the two rotors 946 and 948 disposed inside. As the frame 1210 collapses, it may elongate. The elongation changes the diameter and length and may engage the tips of the blades of the rotors 946 and 948 to assist them in folding and unfolding.

[0425] FIGS. 82A-82D depicts the adjustable hourglass frame 1210. FIG. 82A depicts the frame 1210 is an expanded configuration. The Gearbox 1212 may be intra-corporeal or extra-corporeal. Motor 1000 (not shown) may be intra corporeal or extra corporeal. The frame may house a single impeller blade or contra-rotating blades 946 and 948 as shown. In the depicted embodiment, the caging 1216 is shown open. In some embodiments, the caging 1216 is supported by struts 1214.

[0426] In the case of single impeller, some differences in certain embodiments of the present technology compared with, for example, Cardiobridge's Reitan Catheter pump, Procyrion, and other collapsible devices suggesting membrane blades that cannot work is that the frame 1210 is secured at the inlet and outlet positions inside the blood vessel. There is no retrograde flow from device outlet to device inlet in some embodiments. This is an important advantage of some embodiments and distinguishes some devices in which the impeller diameter is smaller than the open passage upstream to downstream, resulting in retrograde flow, Procyrion, Reitan Catheter Pump, and some devices in development fall in that category.

[0427] FIG. 82B depicts the frame 1210 deployed in an aorta corresponding to the maximum size aorta. FIG. 82C depicts the frame 1210 deployed in an aorta corresponding to the minimum size aorta.

[0428] FIG. 82C depicts the frame 1210 in a collapsed configuration. In some embodiments, the blades of the rotors 946 and 948 may fold upstream or downstream. A runner 1218 may be used to pull bottom struts into sheath. In some embodiments, the pulling mechanism may have a runner 1218. In some embodiments, the pulling mechanism may use just the catheter 1220 (not shown). The depicted embodiment shows the system using the runner 1218 and the catheter 1220 (not shown).

[0429] In some embodiments, the gearbox 1212 is extra-corporeal, there is no runner 1218, and the catheter 1220 collapses the device by enclosing the bottom struts 1214.

[0430] FIG. 83 depicts various embodiments of a shape memory alloy hourglass 1210. In some embodiments this hourglass 1210 may be covered by a biocompatible membrane. The biocompatible covering may be in all 3 sections (inlet, waist, outlet diffuser), or only in some of them (e.g., only in the inlet, only in the waist, only in the outlet diffuser, only in the inlet and waist, only in the inlet and diffuser, only in the waist and the diffuser, etc.). The biocompatible covering may be inside the hourglass, or outside, or inside in some sections and outside in some other sections. In some embodiments, the material is inside and outside as some polymers may need to bond to a second layer to ensure stability. In some embodiments, the hourglass 1210 may be porous in the inlet section 1222. In some embodiments inlet-section porosity is achieved by having no biocompatible covering of the frame at the inlet. In some embodiments, the porosity may be achieved with round holes. In some embodiments, the porosity may be achieved with slits. Some advantages of the porous inlet section 1222 is to provide perfusion between the hourglass shape and the vessel wall. There are intercostal arteries 1224 in the descending aorta, and one of them feeds the spine. If this intercostal artery is not perfused during the operation the patient may be paralyzed. There are currently no systems to provide the surgeon with an early warning. Provision for perfusion between hourglass and blood vessel can be a significant advantage in some embodiments. The perfusion of the intercostal arteries is achieved using the porous inlet section 1222. In some embodiments the inlet section is porous. In some embodiments the outlet section 1226 is porous. In some embodiments the entire hourglass 1210 is porous.

[0431] FIG. 83 also depicts various outlet diffuser 1226 lengths. Some embodiments may have a diffuser 1226 length of about 80 mm. Some embodiments may have a diffuser 1226 length of about 60 mm. Some embodiments may have a diffuser 1226 length of about 40 mm, or lengths greater or less than 40, 60, or 80 mm, or ranges including any two of the foregoing values.

[0432] FIG. 84 illustrates the catheter arrangement for the hourglass 1210 and a device, such as a perfusion device 1230. In some embodiments, a gearbox is needed to power contra-rotating impellers. In some embodiments, a single-impeller pump head is used and a gearbox may not be required. In some embodiments, a gearbox may be used to adjust the output RPM coming from the motor.

[0433] The catheter may include a catheter 1220, a runner 1218, a sleeve 1190 and a flexible shaft 1192. The catheter 1220 may be configured to accommodate the hourglass 1210 and the perfusion device 1230. In some embodiments, the hourglass 1210 and perfusion device 1230 collapse into the catheter 1220. In some embodiments, the catheter 1220 advancing upstream may push the bottom struts 1214 in to initiate folding of device 1230. In some embodiments, the catheter 1220 advancing upstream may push the bottom struts 1214 in to complete folding of the device 1230.

[0434] In some embodiments the runner 1218 may be not be used. In some embodiments, the runner 1218 is used to pull the bottom struts downstream while pushing the catheter 1220 upstream.

[0435] In some embodiment, the gearbox and motor may be intracorporeal, in which case the flexible shaft 1192 is just an electric cable. In some embodiments, the gearbox and motor may be extracorporeal. In some embodiments, the device 1230 has contra-rotating blades. In some embodiments, the flexible shaft 1192 is two co-axial contra-rotating shafts as described elsewhere herein.

[0436] In some embodiments, gearbox may be intracorporeal and the motor extracorporeal. The flexible shaft 1192 may be a single shaft reaching to the intra-corporeal pump head. In an embodiment which includes contra-rotating blades, there may be a gearbox providing two output contra-rotating shafts, one for each impeller.

[0437] In some embodiments, the gearbox and motor may be extra-corporeal. In these embodiments, the flexible shaft 1192 may consist of two contra-rotating shafts.

[0438] With regards to the embodiments shown in FIGS. 85-91, the contra-rotating rotors 946 and 948 are driven by contra-rotating shafts engaging the hubs of the rotors carrying the blades. In some embodiments, the contra-rotation of the shafts may be arranged by direct drive contra-rotating shafts coupled to an extra-corporeal gearbox. In some embodiments, the shafts may be driven by an intracorporeal gearbox located upstream of both impellers. In some embodiments, the shafts may be driven by an intracorporeal gearbox located between the impellers. In some embodiments, the shafts may be driven by an intracorporeal gearbox located downstream of the impellers.

[0439] In some embodiments, the blades 1232 and 1234 may fold upstream. In some embodiments, the blades 1232 may fold downstream. In some embodiments, the upstream blades 1234 may fold upstream. In some embodiments, the downstream blades 1232 may fold downstream. In some embodiments, as the diameter of the hourglass frame collapses, portions of it may elongate upstream or downstream.

[0440] FIG. 85 depicts a system 1240 that includes upstream struts 1242 that are free to rotate about their corresponding hinge only upstream. In the depicted system 1240, the downstream struts 1244 are configured to turn downstream. In some embodiments, the hourglass frame 1210 is configured to collapse with the tips of the blades folding upstream. FIG. 85 shows the sequence of on elongation of segments of hourglass and shows the corresponding sequence of blade tip locations.

[0441] FIG. 86 depicts a system 1250 that can include any number of features similar to system 1240 with various differences. In some embodiments, the upstream and downstream struts 1242 and 1244 are free to rotate about their corresponding hinge in the downstream direction. In some embodiments, the blades 1232 and 1234 will likely fold downstream, but may also fold upstream.

[0442] FIG. 87 depicts the system 1250. If the blades 1234 fold upstream while the struts 1242 fold downstream, then the upstream struts 1242 may be positioned between the folding rotor blades 1234 resulting in the folded device being as short as possible.

[0443] FIG. 88 depicts the folding of the system 1250 or system 1240. Following the folding, the system may be inserted into the catheter 1220 for removal.

[0444] FIG. 89 depicts an upstream runner configuration. In some embodiments, the catheter 1220 collapses the hourglass 1210 and the device elongates upstream. In such a configuration, the blades 1234 and 1232 may fold upstream or downstream.

[0445] FIGS. 90 and 91 depict a downstream runner configuration. In the figure, the runner 1218 pulls the hourglass 1210 downstream and collapses the device. In an alternative embodiment, there is no runner 1218. In some embodiments, the catheter 1220 pushes the bottom struts 1244 up, thus collapsing the mechanism.

[0446] FIG. 92 depicts an embodiment of the collapsible hourglass 1210. In some embodiments, the hourglass 1210 is made of memory-shaped material, metal or plastic, like nitinol. In some embodiments the, supporting struts 1242 and 1244 are made of memory-shaped material, metal or plastic, like nitinol. In some embodiments, the journal bearing hubs are made of memory-shaped material, metal or plastic, like nitinol. In some embodiments, a component made of memory-shaped material, metal or plastic, like nitinol may be made of one memory-shaped material, metal or plastic, like nitinol tube. In some embodiments the collapsible hourglass 1210, supporting struts 1242 and 1244 and journal bearing hubs may be made of one memory-shaped material, metal or plastic, like nitinol tube. In some embodiments, the runner may be an extension of the same memory-shaped material, metal or plastic, like nitinol tube.

[0447] FIGS. 93-96B depict a system 1260. System 1260 can include any number of features similar to system 1250 with various differences. System 1260 includes a device 1262. In some embodiments, a flexible tip 1264 may be attached to the distal end of the device. During the folding phase, the journal bearing 1266 may slide along the flexible tip 1264. The journal bearing 1266 free to move axially, and free to rotate. In some embodiments, the upstream struts 1268 may be fixed to the journal bearing 1266. During folding the upstream struts 1268 curve downwards. Downstream of the upstream struts 1268 may be the upstream propeller 1270 and the downstream propeller 1272. In some embodiments, upstream propeller 1270 is configured for the blades to tilt downstream during folding. In some embodiments, downstream propeller 1272 is configured for the blades to tilt downstream during folding. The gearbox 1274 provides contra-rotation to the propellers 1270 and 1272. The downstream struts 1276 may be fixed to the gearbox 1274 and curve downstream during folding. The flexible core 1277 is connected to the central axle of the gearbox 1274 and transmits torque form the gearbox 1274 to powered components. In some embodiments, the gearbox 1274 provides torque and speed to the propeller 1270. In some embodiments, the gearbox 1274 provides torque and speed to the propeller 1272. The flexible core 1277 may be covered in a sleeve, or plastic dressing, 1278. The sleeve 1278 may serve to protect the flexible core 1277 from blood exposure. The outer hourglass caging 1280 may comprise three segments—the inlet 1282, waist 1284 and outlet 1286. The waist 1284 may have a high radial strength and high longitudinal flexibility. In some embodiments the caging 1280 may be made of memory-shaped material, metal or plastic, like nitinol. Pulling strings 1288 connect the caging 1280 to the runner 1290. The pulling strings 1288 may be diffuser struts or strings. The runner 1290 is pulled by the operator to collapse the caging 1280. The collapsing may be similar to how an umbrella collapses. When the downstream struts 1276 are forced into the catheter, the waist 1284 elongates axially and shrinks radially. As a result, the journal bearing 1266 may be pushed further upstream.

[0448] FIG. 96A depicts the device 1262 in an expanded configuration. FIG. 96B depicts the device 1262 in a collapsed configuration.

[0449] FIGS. 97-99B depict a device 1300. Device 1300 can include any number of features similar to device 1262 with various differences. In some embodiments, the upstream struts 1268 fold upstream. The downstream struts 1276 fold downstream. In this embodiment the journal bearing 1266 may be fixed in place. The upstream propeller 1270 hub rotates with the upstream propeller 1270. The upstream struts 1268 may be configured to curve upstream during device folding. The downstream struts 1276 may curved downstream during device folding. When the runner 1290 is pulled against the drive shaft the struts fold to enable the device to transform into the collapsed configuration. The device 1300 may not include a flexible tip.

[0450] FIG. 99A depicts the device 1300 in an expanded configuration. FIG. 99B depicts the device 1300 in a collapsed configuration.

[0451] FIGS. 100-102 depict a system 1310. System 1310 is similar to system 1260 with various differences. The system 1310 includes the device 1312. Device 1312 is similar to device 1262 with various differences. System 1310 folds the device 1312 via the catheter 1220. No runner is used in some embodiments of system 1310. When the catheter 1220 is pushed upstream against the diffuser struts or strings 1288, and/or the caging 1280, the downstream struts 1276 tend to fold upstream and the upstream struts 1268 tend to fold downstream. In some embodiments, the journal bearing 1266 may be pushed further upstream. In some embodiment, the strings or diffuser struts 1268 may be connected to the caging 1280 on one end. In some embodiment, the strings or diffuser struts 1268 may be connected to the flexible shaft 1277 on a second end.

[0452] FIGS. 103A and 103B depicts system 1310. In this embodiment, the blades may tend to fold upwards. The blades may include a small upward inclination in the open position. This upward inclination may provide that when the blade tips are exposed to the radial force from folding caging, the blades fold upstream. FIG. 103A depicts the device 1312 in an expanded configuration. FIG. 103B depicts the device 1312 in a collapsed configuration.

[0453] FIGS. 104-107 depict example perfusion devices. In some embodiments, the rotating blade tips 1314 are 0.1 mm to 2 mm from the inside diameter of the waist 1284 of the hourglass cage frame 1280. The impeller axis is secured in place by struts, such as struts 1268, and bearings, such as journal bearing 1266. The struts are secured at one end on the bearings and at the other end on the frame 1280. There is also a similar arrangement securing the flexible shaft centerline with struts and a hub at the outlet of the diffuser (diffuser struts or strings).

[0454] In some embodiments, the whole cage 1280 and the struts 1268 and 1276 may be made of one memory-shaped material, metal or plastic, like nitinol tube. Manufacturing may in some cases require cutting out surplus segments and welding in some joints. The journal bearing hubs may be part of the same memory-shaped material, metal or plastic, like nitinol tube, see, e.g., FIGS. 106 and 107.

[0455] FIGS. 108 and 109 depict blades 1320 folding at the hub 1322. The blades 1320 may fold either upstream. The blades 1320 may fold downstream. The blades 1320 may fold in either direction. The blades 1320 may fold for insertion in a catheter. The blades 1320 may fold in a collapsible hourglass cage. In the example shown in FIG. 108, the blades 1320 are folded downstream for insertion. After insertion, the catheter 1220 is moved downstream in relation to the blades 1320 in order to unfold the mechanism. To fold and remove the mechanism, the catheter 1220 is moved upstream in relation to the rotors, and the blades 1320 fold upstream. In some embodiment the blades may be made of memory-shaped material, metal or plastic, like nitinol. In some embodiments, the blades may have a rotatable region 1322. In some embodiments, the rotatable region 1322 may be made of a flexible material.

[0456] FIGS. 110 and 111 depict folding blades 1320. Each folding blade 1320 may have a center strut 1324 made of memory shape alloy. The center strut 1324 may be surrounded by an airfoil shape 1326. The airfoil 1326 may be made of biocompatible metal. The airfoil 1326 may be made of biocompatible plastic. In some embodiments the folding blade may include a memory-shaped material, metal or plastic, like nitinol frame in the shape of a blade, the blade covered by a biocompatible material. In these embodiments, the blades may wrap into the hourglass cage 1280 and catheter 1220 for implantation and removal. The material surrounding the center strut 1324 may be twisted from hub to tip to accommodate flow considerations. In some embodiments the center strut 1324 will not protrude from the airfoil shape 1326. The center strut 1324 may be made in several thin layers using 2D deposition techniques.

[0457] FIG. 112 depicts a rigid blade 1340 with flexible strut 1342. The central strut 1342 may be composed of a memory shape alloy. In some embodiments the shape memory alloy may be memory-shaped material, metal or plastic, like nitinol. The strut 1342 may be surrounded by a frame 1344. The strut 1342 may be comprised of memory-shaped material, metal or plastic, like nitinol. The frame 1344 may comprise memory-shaped material, metal or plastic, like nitinol. In some embodiments, the frame 1344 may be covered by biocompatible membrane. Any process may be used to do this including using a biocompatible material netting. In some embodiments, the frame 1344 may be covered by flexible memory-shaped material, metal or plastic, like nitinol sheets. Any process may be used to do this including using a flexible fine netting of memory-shaped material, metal or plastic, like nitinol. A filling material 1346 may be used. The overall blade 1340 is stiff enough to carry the requisite hydrodynamic forces but flexible enough at the hub to bend around the shaft in the collapsed state. In some embodiments, the strut 1342, may be a metal strip. In some embodiments, the strut 1342 may be a series of metal strips. In some embodiments, the strut 1342 may be a lattice of metal strips. The strut 1342 may be configured to be made stiff to bending along the direction of the resultant force of lift and drag. In some embodiments, the strut 1342 is predominantly stiff upstream making the strut 1342 suitable for pumping action. The strut 1342 may be weaker when bending perpendicular to this direction. In some embodiments, the strut 1342 may be predominantly less stiff downstream to enable folding. This concept is further explained elsewhere in this document.

[0458] FIG. 113 that the forces applied on a single strip 1358 connecting blade 1356 to hub 1354, results in bending of the strip 1358. If several strips 1360 are used to connect blade to hub, one strip bends and the remaining strips buckle. Bending of strips in a particular inclination to the axis alpha is shown in the figure. The direction of blade bending can be as described herein.

[0459] FIG. 113 also shows the top views 1350 and 1352. These views show, upstream to downstream, of downstream blade with stagger angle with leading edge NW to trailing edge SE.

[0460] If hub 1354 turns clockwise, then blade 1356 turns counter-clockwise and upstream.

[0461] If hub 1354 turns counter-clockwise, then blade 1356 turns clockwise and downstream.

[0462] The upstream blades and their hub turn in the opposite direction to downstream blades. Their stagger angle is also in the opposite direction with leading edge NE and trailing edge SW. Therefore, the upstream blades will turn to bend upstream (or downstream) in the same direction the downstream blades bend.

[0463] FIG. 114 depicts a blade mesh in an unbent configuration and in a bent configuration. In some embodiments a blade 1370 can be a wide span non-rigid blade. In some embodiments, the blade 1370 can be made from a memory-shaped material, metal or plastic, like nitinol mesh. The large-span blade 1370 can help with the hydrodynamic performance. A memory-shaped material, metal or plastic, like nitinoll meshed blade may be able to deform under a certain loading. Deformation under loading may be functional for retraction.

[0464] FIGS. 115 and 116 depict the blades 1370 mounted to a hub 1372. In some embodiments, the blades 1370 may be covered in a thin layer of PTFE. In some embodiments, the blades 1370 are covered in another biocompatible membrane. Due to the blade 1370 flexibility, the blades 1370, such as meshed blades can be folded around the hub. Especially, it may allow the blades 1370 to be folder around the hub 1372 when the catheter 1220 is moved upward. This could be advantageous to reduce the overall system size. The blade 1370 could be welded directly to the hub 1372. Welding to the hub 1372 may enable maintaining the hydro dynamically designed twisted shape of the blades in the vicinity near the hub, without compromising performance. In some cases the blades may be flat plates bent to a blade shape. FIG. 126B, described herein below, illustrates a flat plate, bent to blade shape.

[0465] FIG. 117 shows an example embodiment wherein, in their relaxed and not rotating shape, the blade tips 1374 may be pointed slightly downstream. In some embodiments the blades may be pointed downwards by about 15 degrees. In operating conditions, the hydrodynamic forces plus the centrifugal forces bring the blade close to the horizontal position.

[0466] FIG. 118 depicts an embodiment of the blades 1370 wherein a stop mechanism 1376 may be attached at the hub to prevent the blades from bending too far upstream.

[0467] FIGS. 119 and 120 depict an example embodiment of a flexible hub. In this example embodiment the blades 1370 bend at the hub 1372. The bent blades 1370 can slide into the catheter 1220. In this example, the gear teeth 1376 shown inside the hub are the ring gear of an epicyclic gearbox. In some embodiment three flexible struts 1378 are used to connect each blade 1370 to the hub 1372.

[0468] FIG. 121 shows a blade system 1380. The blade supporting structure 1382 may be made of one tube of shape memory alloy. In some embodiments the shape memory alloy may be memory-shaped material, metal or plastic, like nitinol. In some embodiments, the tube is cut and with extra blade material is added around the base shape. In some embodiments, a manufacturing step may be to cut-out the blade shape from a selected memory-shaped material, metal or plastic, like nitinol tube. Another manufacturing step may be to deform the cut tube 1384 blade shape. In the depicted embodiment, the tube is cut into four pieces. In some embodiments, the minimum thickness of the memory-shaped material, metal or plastic, like nitinol frame may be determined by foldability considerations. In some embodiments, for each blade, the cut-out from the memory-shaped material, metal or plastic, like nitinol tubing should be deformed from the hub to tip into a prescribed curvature. In some embodiments, the prescribed curvature is selected to match the corresponding blade body curvature. In some embodiments the curvature varies from the hub to tip. The folding hub section of memory-shaped material, metal or plastic, like nitinol may have various shapes of cuts in it to weaken it for bending in some directions, and strengthening it against bending in other directions. In some embodiments, additional metal may be added to the cut memory-shaped material, metal or plastic, like nitinol tube to achieve a desired curvature and frame 1386 shape. In some embodiments, a biocompatible material may be added on top of the metal frame. In some embodiments, biocompatible material may be added to achieve a desired blade 1370 shape.

[0469] FIG. 122 depicts a set of blades 1370 attached to a hub 1372. In some embodiments, these blades are formed of a shape memory alloy, such as memory-shaped material, metal or plastic, like nitinol. The blades 1370 may be configured to wrap around the hub 1372. The blades 1370 may be configured such that they all can be wrapped around the hub simultaneously. The catheter 1220 may be sized and configured to accommodate these folded blades 1370. In some embodiments, the outer diameter of the catheter 1220 may be about 4 mm. In some embodiments, the outer diameter of the hub 1372 may be about 2 mm. In some embodiments, the hub 1372 and the folded blades 1372 may be configured to fit inside a 12 Fr tube. In some embodiment the blades 1370 may be made of a flexible material.

[0470] FIGS. 123A, 123B, and 123C depict the wrapping of various blade 1370 configurations around the hub 1372. Blades 1370 with wider chord length. FIG. 123A embodiments may be made thinner than the 4 mm chord blades in order to fit in a size 12 French catheter, for example. As the chord length of the blades increases, the amount of blade overlap may also increase. The effect is that higher chord length blades will sometimes tend to overlap more. This additional overlapping will tend to increase the minimum interior diameter of the catheter for a constant blade thickness. Alternatively, to maintain a constant interior diameter of the catheter, the blade thickness must decrease as blade chord length increases.

[0471] FIGS. 124 and 125 depict the deformable blade 1370. In some embodiments, the blade is made of a shape memory alloy lattice. In some embodiments, the lattice may be covered by PTFE. The shape memory alloy lattice may be advantageous to enable the chord L to be deformable in order to fit in the available space. In some embodiments the space may be limited by the configuration of the catheter 1220.

[0472] FIG. 126A depicts another example embodiment. In this embodiment, the blade 1370 is made by cutting a memory shape alloy tube into a lattice to form a first surface of the blade 1370. In some embodiments, the first surface may be the suction surface 1390. In some embodiments, the second surface is also made of a shape memory alloy mesh. In some embodiments, the second surface may be the pressure surface 1392. Welding, adhesives, or other coupling techniques may be used to couple the first surface to the second surface. In some embodiments, the shape memory alloy may be memory-shaped material, metal or plastic, like nitinol. In some embodiments, the pressure surface 1392 may be welded to the suction surface 1390 along the leading edge and the trailing edge. FIG. 126B illustrates a comparison of flat plate (bent to blade shape) versus aerofoil shape blades. In some embodiments, the flat plate is advantageous since it can be easier to manufacture and the performance penalty is small, although aerofoil cross-section blades can be utilized in other embodiments.

[0473] FIG. 127 depicts an embodiment of a screw-worm gear blade folding mechanism 1400. The mechanism 1400 includes foldable, or feathering blades 1370. This folding structure is a new application of foldable propeller to heart-assist pumps. The mechanism 1400 may include a stationary component of the structure upstream of the blades 1370, and another stationary component downstream of the blades 1370. In this example, the gearbox 1404 is shown upstream of the upstream impeller.

[0474] FIG. 128 depicts the gearing system 1404. In some embodiments, the gearing system 1404 is integrated at the tip, proximal to the heart. In some embodiments, the gearing system 1404 may be located the bottom, distal to the heart. The FIG. 128 shows the case with upstream gearing 1404. Two concentric shafts 1406, coming of the gearing 1404, rotate in opposite directions. The outer shaft 1410 may be connected to the first (upstream) rotor 946 (not shown). The inner shaft 1414 may be connected to the second (downstream) rotor 948 (not shown). In some embodiments, a worm screw shape 1408 may be disposed on the outer shaft 1410. A worm screw shape 1412 (not shown) may be disposed on the inner shaft 1414, connected to the second rotor 948 (distal, downstream rotor).

[0475] FIG. 129 depicts each blade 1370 equipped with a pinion 1416. In some embodiments, the pinion 1416 is configures to engage the worm screws 1412 or 1408. The system may further include two asymmetric cams 1418. The cams 1418 may secure the blades 1370 in upper slots 1420 (not shown) and lower slots 1422 (not shown). The slot that blade 1370 is secured to depends on the blade angle.

[0476] FIG. 130 depicts how, in some embodiments, as the worm screw turns 1412 or 1408 turns, the corresponding blade 1370 may open and close. This action may be comparable to a corkscrew opening a bottle of wine.

[0477] FIG. 131 depicts a configuration in which the blades 1370 are initially folded. In the folded position, the top edge of each cam 1418 is restricted in the top slot 1420 on the stationary gearing system. This configuration may prevent the blades 1370 from rotating. When the worm screw 1412 or 1408 turns, as long as the cams 1418 are in slots, the blades are unfolding. While the cams 1418 remain in the slots 1420 they prevent blade 1370 rotation.

[0478] FIG. 132 depicts the screw worm gear folding system 1400. Specifically the FIG. 132 shows that as soon as the cams 1418 are released from the top slot 1420, the blades 1370 are free to rotate. At this point, the bottom tip of the cams 1418 engages the bottom slots 1422. In some embodiments, the bottom slots are coupled to the rotating shaft, so that the blades 1370 will spin with the shaft.

[0479] The same mechanism 1400 as described in FIG. 127-132 can be used for the downstream rotor. In some embodiments, the mechanism 1400 may have differences when applied to the upstream rotor and the downstream rotor.

[0480] FIG. 133 depicts a system 1430 that can include any number of features similar to mechanism 1400 with various differences. The system 1430 includes an alternative folding arrangement upstream. The blades 1370 fold upstream. The mechanism may be similar to feathering marine propellers. In some embodiments, a pin is used to prevent blade 1370 rotation. The size of the hub diameter is for illustration purposes. In some embodiments, the hub diameter may be smaller than 4 mm. In some embodiments, the hub diameter may be larger than 4 mm.

[0481] FIG. 134 depicts prior art marine feathering propellers.

[0482] FIGS. 135 and 136 depict how the mechanism 1400 may utilize the axial displacement of the central shaft 1401 to engage and disengage the gearbox 1404. In some embodiments, this is achieved using a cam arrangement in the central shaft 1401 that in one position keeps the blades unfolded, and in another position allows them to fold upstream.

[0483] FIG. 136 depicts another embodiment in which a spring-loaded sliding pin 1440 may be used to lock the blades in the folded or unfolded position. The sliding pin 1440 and spring mechanism 1442 locks the blade 1370 in its position.

[0484] FIG. 137 depicts how the blades 1370 will be opened when the central shaft 1401 is pushed forward. FIG. 138 is another view of FIG. 137.

[0485] FIGS. 139-142 depicts an axle and pin locking mechanism 1450. In some embodiments, the blades 1370 are raised by popping them into place. The blades 1370 may be free to hang downstream for insertion in the folded state. Upon spinning the shaft, the centrifugal and hydrodynamic forces pop the blades 1370 into the open position, and keep them there until it is time for removal. In some embodiments, when it is time for removal, the device is set to a higher RPM, e.g. at 150% of maximum design rpm. At the higher RPM, the hydrodynamic forces pop the blades 1370 past the pin 1452 and into the upstream position. The blades 1370 in the upstream position are ready for removal. In another embodiment, the catheter 1220 pushes the blades 1370 upstream past the retaining clips.

[0486] FIG. 140 depicts the various configuration of the axle and pin locking mechanism 1450.

[0487] FIG. 141 depicts the axle and pin locking mechanism 1450. In some embodiments, the blades are kept in the horizontal position by hydrodynamic and centrifugal forces resulting from blades 1370 rotation. When the blades 1370 stop rotating they may tend to a folded position by gravity and/or blood flow downstream.

[0488] FIG. 143 depicts blades 1370 folded upstream on top of helical structures 1456. In some embodiments the blades 1370 could both fold downstream. In some embodiments one set of blades 1370 folds upstream and one set of blades 1370 folds downstream.

[0489] FIG. 144 depicts a catheter arrangement 1458 with runner 1460.

[0490] FIG. 145 depicts a catheter arrangement 1462 without a runner.

[0491] FIG. 146 depicts an hourglass cage 1464 with perforated inlets 1466. In some embodiments, the perforations may be slits 1468. In some embodiments, the perforations may be round.

[0492] FIG. 147 depicts a heart perfusion system 1470. Some embodiments include contra-rotating rotors 1472 inside an hourglass cage 1474. The intra-corporeal gearbox 1476 may be just downstream of collapsed hourglass 1474. The intra-corporeal motor 1478 may be just downstream of gearbox 1476. The cable 1480 may supply electric power and communication to a controller 1482 outside the body. The system 1470 may be recoverable by catheter 1220. Items in line outside the collapsed hourglass 1474 fit in smaller catheter than if they were inside the hourglass 1474. In some embodiments, the heart perfusion system 1470 includes an inlet with wire frame only, as shown in FIG. 152 described herein.

[0493] In some embodiments, a runner may be used to assist in collapsing the hourglass 1474.

[0494] In some embodiments, the gearbox 1476 and motor 1478 fit inside the diffuser of the hourglass 1474.

[0495] FIG. 148 depicts a system 1481. System 1481 is similar to system 1470 with various differences. Contra-rotating rotors 1472 with motor 1480 and gearbox 1482 extra-corporeal. Contra-rotating flex shafts 1484 supply power to pump head. In some embodiments, the system 1481 is recoverable by catheter 1220 only.

[0496] FIG. 149 depicts an embodiment of system 1481. In this embodiments the system is recoverable by catheter 1220 and runner 1484.

[0497] FIG. 150 depicts a system 1486. System 1486 is similar to system 1470 with various differences. In some embodiments the contra-rotating rotors 1472 are disposed inside the collapsed hourglass 1474. In some embodiments the, intra-corporeal gearbox is positioned just downstream of collapsed hourglass 1482. The motor 1480 is extra-corporeal. In some embodiments, this system is recoverable by catheter 1220.

[0498] FIG. 151 depicts contra-rotating rotors 1472 inside the hourglass 1474. The intra-corporeal gearbox is located just downstream of collapsed hourglass 1474. The motor 1480 is extra-corporeal motor. In some embodiments, recoverable 1220 by catheter and runner 1484. The runner is in FIG. 151.

[0499] FIG. 152 illustrates this inlet-section porosity. There is just mesh located at the inlet. In some embodiments inlet-section porosity is achieved by having no biocompatible covering of the frame at the inlet.

[0500] FIG. 153A illustrates another embodiment of a circulatory support device 1530 in an expanded configuration. A nose cone 1 is mounted on the top of the axial-radial bearing 2 at the end of an elongate member. The nose cone 1 can be relatively short, and stationary. An axial-radial bearing 2 can be configured to prevent rotor(s) from one or both of axial and radial displacement. Top centralizer struts 3 can extend radially outward from the elongate member and are configured to connect the bearing 2 to the housing 22, which can be a stent with a generally hourglass or other geometry as disclosed elsewhere herein. Top centralizer struts 3 thus centering the overall pump head. Any number of struts 3 can be present, such as two, three, four, five, or more or less struts, or ranges including any two of the foregoing values. First rotor 4 can include a shaped tip head configured to be attached to the bearing 2. Second rotor 5 can include a long rigid hub to allow the bearing 2 to slide freely during the retrieval phase. First radial locating ring (e.g., loose bearing) 6 can be configured to prevent rotors, such as second rotor 5 from radial displacement, while still allowing the second rotor 5 the freedom to travel axially. Bottom centralizing struts 7 are configured to extend radially outwardly from the elongate member, and are configured to connect the first radial locating ring 6 to the housing 22, thus centering the pump head. A slider 8 can connect a rotating hub (e.g., of rotor(s) to a sleeve or sheath 13, part of which can include bi-flex shafts or bellows for example. A plurality, such as two or more contra-rotating shafts 9 can transmit the torque from an external power to first rotor 4 and second rotor 5. In some embodiments, part of the sheath 13 can include an extendable sleeve 10 (e.g., bellows made of PTFE or another material) which covers the shafts and connects one end to the slider, and another end to a third radial locating ring (e.g., loose bearing) 12. Cords 11 can connect the lower end of a diffuser to a third radial locating ring 12. A biocompatible stationary sleeve or sheath 13 can cover the contra-rotating shafts 9. In some configurations, the sheath 13 can also serve as a retrieving catheter. Slider 8, sleeve 10, and third radial locating ring 12 can be configured to slide inside of sleeve 13. A coupling mechanism 15 can be configured to transmit the contra-rotating motion from the gear box to the contra-rotating shafts.

[0501] FIG. 153B illustrates the circulatory support device 1530 of FIG. 153A in a folded or radially compressed configuration for delivery and/or removal from the body. Also illustrated are placement and retrieving rods 16, which can include in some cases one for each shaft, used only during implantation and retrieval, to enable sheath 13 to go over the pump head and collapse it inside it, while holding the contra-rotating shafts in place. Catheter 17 can be utilized instead of sheath 13, and can be shorter than sheath 13 in some cases as extending only partially in between the distance between bearing 12 and coupling mechanism 15 and/or rods 16, such as less than about 90%, 80%, 70%, 60%, 50%, or less of the distance, or ranges including any two of the foregoing values.

[0502] In some embodiments, blades of a propeller or impeller can be made of flat plates of nitinol curved into a 3D twisted shape.

[0503] In some embodiments, blades can take on an airfoil geometry. In some embodiments, as illustrated in FIG. 154A-154C, the blades can include a base component 1560 with a “dogbone” like shape, with a first width at a first end 1541, a first transition zone 1542, wherein the width decreases (e.g., gradually decreases as shown), a central portion 1543 with a second width that is less than the first width, a second transition zone 1544, wherein the width increases (e.g., gradually increases as shown) to a third width at a second end 1545, wherein the first width can be equal to the third width, and the first width and the third width are greater than the second width. In some embodiments, the second width is about, between about, or no more than about 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% of the first width (and the third width), or ranges including any two of the foregoing values. In some embodiments, the length of the central portion 1543 is about, between about, or no more than about 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% of the length of the entire blade 1560 from the first end 1541 to the second end 1545, or ranges including any two of the foregoing values. The base component 1560 can be welded or otherwise attached to a shaft 1570, such as a cylindrical shaft as shown. Two or more outer blade elements 1571, 1572, which can include inner facing surfaces with cut outs with the geometry or substantially with the geometry of the base component 1560 in order to fit the base component 1560 within the elements 1571, 1572. The outer facing surfaces of outer blade elements 1571 can form an airfoil shape in some cases. The outer blade elements 1571, 1572 can be made of a biocompatible material such as a metal or plastic, and then fused or otherwise attached together.

[0504] In some embodiments, as illustrated in FIG. 154D, threads 1590, 1591 having respective lengths 1590L, 1591L may be used to secure the hubs onto the bidirectional hubs. The threads 1590, 1591 can be in a rotation to screw in the shafts onto the hubs during pumping operation (and one or more, or only one of them will be reverse thread).

[0505] As illustrated in FIG. 155, a plurality of contra-rotating shafts can be made of coils arranged in a way so that the coils act as screw pumps between them, and between the outer coil and external shaft sheath or shaft sleeve, so that it pumps lubricant in one direction. In an alternative configuration, the same action with unlubricated coils may be used to pump any material that is fretted away from the coil or sheath surfaces is pumped away from the internal pump head and towards the extra-corporeal gearbox.

[0506] FIGS. 156A-156C illustrate the hourglass-shaped pump head 1800 installed and unfolded in the vascular system. FIG. 156A is a first view. FIG. 156B is a second view showing more of the vasculature. FIG. 156C is a third view with a covering of biocompatible material 1774. The openings 1776 in the biocompatible material allow perfusion between the outside perimeter of the pump head 1800 and the inside perimeter of the blood vessel, In this configuration, the pump head can be placed in any blood vessel. In particular, the pump head 1800 can be placed in the descending aorta, upstream of the kidney arteries. In this location, openings 1776 provide perfusion to the intercostal arteries, and the spinal artery. The pump head 1800 and the overall device 1700 can have any of the features described herein.

[0507] FIGS. 157A-157B illustrate of the overall device 1700. FIG. 157A is a top view of the system. FIG. 157B is a side view of the system.

[0508] The system can include a shaft sheath 1704. The shaft sheath 1704 can be non-rotating. The shaft sheath 1704 can be hollow. The shaft sheath 1704 can include flexible contra-rotating shafts, as described herein. The flexible contra-rotating shafts can be disposed within the shaft sheath 1704. In this illustration, the flexible contra-rotating shafts can have a length between 600 mm and 1800 mm long. The flexible contra-rotating shafts can have a length of 100 mm, 200 mm, 300 mm, 400 mm, 500 mm, 600 mm, 700 mm, 800 mm, 900 mm, 1000 mm, 1100 mm, 1200 mm, 1300 mm, 1400 mm, 1500 mm, 1600 mm, 1700 mm, 1800 mm, or any range of two of the foregoing values. In some embodiments, the flexible contra-rotating shafts can have a length between 300 mm and 1800 mm long.

[0509] The system can include motors 1706, 1708. The system can include two motors. The system can include any number of motors. The number of motors can correspond to the number of impellers. The number of motors can correspond to the number of shafts that rotate one or more impellers. The motors 1706, 1708 can be extra-corporeal. The motors 1706, 1708 can be contra-rotating motors. The extra-corporeal contra-rotating motors 1706, 1708 can drive other components of the system as described herein.

[0510] The system can include impellers 1710, 1712 with hubs and blades. The impeller 1710 can be upstream. The impeller 1712 can be downstream. Each impeller can include one or more blades on its hub, e.g., one blade, two blades, three blades, four blades, five blades, six blades, seven blades, eight blades, nine blades, ten blades, eleven blades, twelve blades, thirteen blades, fourteen blades, fifteen blades, sixteen blades, or more, or any range of two of the foregoing values. The blades of impellers 1710, 1712 can be folding blades. The impellers 1710, 1712 can be contra-rotating. The impeller 1710 can rotate in a first direction. The impeller 1712 can rotate in a second direction, opposite the first direction, and the blades can be mounted at angles to the axial direction so that both impellers propel blood flow downstream. The flexible contra-rotating shafts connect the extra-corporeal contra-rotating motors 1706, 1708 to the folding contra-rotating impellers 1710, 1712.

[0511] The system can include an hourglass frame 1714. The hourglass frame 1714 can be folding. The hourglass frame 1714 can include one or more segments that form the frame. The hourglass frame 1714 can include a wider inlet 1766. The hourglass frame 1714 can include a wider outlet or diffuser 1770. The hourglass frame 1714 can include a narrower waist 1768. The folding blades of contra-rotating impellers 1710, 1712 are inside the folding hourglass frame 1714. The folding contra-rotating blades of impellers 1710, 1712 can be within the narrower waist 1768. The folding contra-rotating blades of impellers 1710, 1712 form a pump head within the vasculature of the patient.

[0512] The system can include a catheter 1716. The catheter 1716 can include one or more flexible shafts connecting the motors to the impellers. The pump head including the folding contra-rotating impellers 1710, 1712 in the hourglass frame 1714 can be collapsed inside the catheter 1716. The pump head can be collapsed for implantation. The pump head can be collapsed for removal. The catheter 1716 can be flexible. The catheter 1716 can extend to just downstream of the outlet of the diffuser 1770 of the hourglass frame 1714. The catheter 1716 is shown in S shape for illustrative purposes. The catheter 1716 can be flexible. The catheter 1716 can be flexible to the degree required for the surgical procedure. The S shape of the catheter 1716 may not be the shape the device assumes when implanted. The catheter 1716 can be hollow. The shaft sheath 1704 can be disposed within the catheter 1716. The flexible contra-rotating shafts are inside the shaft sheath 1704 and connect the extra-corporeal contra-rotating motors 1706, 1708 to the folding contra-rotating blades 1710, 1712, which are inside the folding hourglass frame 1714. The hourglass-shaped pump head 1800 is collapsed inside the flexible catheter 1716 for implantation and removal. The system can include a catheter introducer 1718. The catheter 1716 is inside the catheter introducer 1718. The catheter is flexible and extending to just downstream of the diffuser outlet. In this illustration the flexible contra-rotating shaft is 600-1800 mm long. The pump head 1800 can include an hourglass shape, biocompatible membrane, struts, shaft holders, impellers and impeller diving shafts, plus the impeller interconnect, as described herein.

[0513] FIGS. 158A-158B illustrate another view of the system, where the shafts and shaft sheath may be shorter than above, and may not be flexible. The hourglass frame 1714 can be collapsed inside the catheter 1716. The catheter 1716 is inside the catheter introducer 1718, which goes through the skin. In this illustration, the contra-rotating shaft can have a length between 300 mm and 600 mm long. The contra-rotating shaft can be 300 mm, 400 mm, 500 mm, 600 mm, 700 mm, 800 mm, 900 mm, 1000 mm, 1100 mm, 1200 mm, 1300 mm, 1400 mm, 1500 mm, 1600 mm, 1700 mm, 1800 mm, or any range of two of the foregoing values. In some embodiments, the flexible contra-rotating shafts can have a length between 300 mm and 1800 mm long. There is a symbolic cut in the drawing in the axial length of 1718 indicating it is longer than shown. or any range of two of the foregoing values. The catheter 1716 can be rigid. In some embodiments, the shaft of the catheter 1716 can be longer. In some embodiments, the catheter 1716 can be flexible, as shown in FIG. 157A.

[0514] The hourglass frame 1714 can be collapsed by moving the catheter 1716 upstream along the shaft sheath 1704. The catheter 1716 moves, thereby increasing the length of the shaft sheath 1704 that is uncovered near the motors 1706, 1708. The catheter 1716 with Luer fittings can have a fixed length. The catheter introducer 1718 with Luer fittings can have a fixed length. The length of the catheter 1716 can be sufficient to collapse the hourglass frame 1714. The length of the catheter introducer 1718 can be sufficient to allow the catheter to be percutaneously implanted in the vasculature. FIG. 158A illustrates the pump head and the hourglass frame 1714 expanded. The catheter 1716 can be retracted. The catheter 1716 can be retracted toward the motors. FIG. 158B illustrates the pump head and the hourglass frame 1714 collapsed. The catheter 1716 can be advanced. The catheter 1716 can be advanced away from the motors. The catheter introducer 1718 can be positioned across the skin of the patient and into a blood vessel, such as the femoral artery.

[0515] The system can include motors 1706, 1708. The motor 1706 can have a solid motor shaft. The motor shaft can be connected via a coupling. The coupling can be just upstream of the motor 1706. The motor shaft can be connected to a shaft 1720, described herein. The shaft 1720 can be called the core shaft. The core shaft 1720 can extend upstream to drive the upstream impeller 1710. The core shaft 1720 can be rigidly connected to the tip extension or connector 1722, upstream of impeller 1710, described herein. The tip extension 1722 can be covered by a nose cone 1724. The core shaft 1720 is co-axial to a peripheral shaft 1726. These two shafts are co-axial.

[0516] The motor 1708 can have a hollow motor shaft. The hollow motor shaft can be connected via a coupling. The coupling can be just upstream of the motor 1708. The motor shaft can be connected to the peripheral shaft 1726, described herein. The peripheral shaft 1726 can be called the peripheral shaft. The peripheral shaft 1726 can be hollow. The core shaft 1720 can be disposed within the peripheral shaft 1726. The peripheral shaft 1726 can at least partially surround the core shaft 1720 around the circumference of the core shaft 1720. The peripheral shaft 1726 can at least partially surround the core shaft 1720 along the length of the core shaft 1720. The core shaft 1720 of motor 1706 can go through the peripheral shaft 1726 of motor 1708. The core shaft 1720 of motor 1706 can be coaxial with the peripheral shaft 1726 of motor 1708. The peripheral shaft 1726 can be peripheral to the core shaft 1720. The peripheral shaft 1726 can extend upstream to drive the downstream impeller 1712.

[0517] The core shaft 1720 and the peripheral shaft 1726 can be disposed within the shaft sheath 1704. The shaft sheath 1704 can be a non-rotating shaft sheath. The shaft sheath 1704 can extend from the forward part of the upstream coupling of the motor 1708. The non-rotating shaft sheath 1704 can extend to just downstream of the diffuser 1770. The non-rotating shaft sheath 1704 can be connected to shaft holder 1734, as described herein.

[0518] Excluding the luers on the catheter introducer 1718, Figure also shows four Luers, two Luers 1740, 1742 on the catheter 1716, and two Luers 1736, 1738 on stationary fluid reservoirs located on either side of the downstream-impeller motor 1708, described herein. Three Luers 1736, 1738, 1740 are used to introduce biocompatible flushing or lubricant between rotating components, and the fourth Luer 1742 is used to expand a sack or bladder at the distal end of the catheter 1716, and seal the space between the catheter 1716 and the stationary shaft sheath 1704. This last function of 1742 could also be achieved with a mechanical seal, like a O ring, between the shaft sheath and the catheter. In some embodiments, there are two extra Luers or ports on the catheter introducer 1718. These ports can serve as flush or lubrication paths.

[0519] FIGS. 158A-158B illustrate four Luer connections 1736, 1738, 1740, 1742, described herein. In some embodiments, three of the Luer connections 1736, 1738, 1740 are used to introduce flushing between rotating components. In some embodiments, one of the Luer connection 1742 is used to expand a sack or bladder at the distal end of the catheter 1716. In some embodiments, the Luer connection 1742 is used to expand a sack or bladder to seal the space between the catheter 1716 and the shaft sheath 1704.

[0520] FIGS. 159A-159C illustrate mechanical coupling arrangements. One mechanical coupling connects the motor 1706 to the core shaft 1720. The mechanical coupling can connect a motor shaft to the core shaft 1720. The mechanical coupling can hold the components in a coaxial arrangement. The core shaft 1720 can be solid. The core shaft 1720 can be flexible. The core shaft 1720 extends between the motors 1706, 1708, and through to the tip extender described herein. The core shaft 1720 drives the upstream rotor or impeller 1710. The core shaft 1720 extends to the upstream, furthermost tip of the pump shaft. FIG. 159A is a side view with the sealed arrangement covered. The sealed arrangement can be bolted to the motor 1708. FIG. 159B is a side view with the sealed arrangement illustrated. FIG. 173C is another side view with the sealed arrangement illustrated. The system can include one or more fluid pathways. The sealed arrangement can provide a fluid pathway for biocompatible flushing or lubricant. The Luer connection 1736 can be disposed between the motors 1706, 1708.

[0521] The arrangement can include one or more features to provide an effective fluid seal. The arrangement can provide one or more features to provide alignment between shafts. The system can include bearings 1744. The bearings 1744 can be sealed. The system can include a plug 1746. The sealed bearings 1744 and the plug 1746 can secure the motor shafts. The sealed bearings 1744 can align the core shaft 1720 with motor shaft of the motor 1708. The sealed bearings 1744 can align the core shaft 1720 with peripheral shaft 1726. The sealed bearings 1744 and the plug 1746 can also provide sealing for biocompatible flushing or lubricant path, via the Luer connection 1736. The sealed bearings 1744 and the plug 1746 can also provide sealing for biocompatible flushing or lubricant path to the space between the core shaft 1720 and the peripheral shaft 1726. The Luer connection 1736 can be disposed between the sealed bearings 1744.

[0522] The system can include another sealed coupling on the upstream proximal side of the motor 1708. The sealed coupling connects the motor 1708 to the peripheral shaft 1726. The sealed coupling can connect a motor shaft to the peripheral shaft 1726. The sealed coupling can hold the components in a coaxial arrangement. The peripheral shaft 1726 can be hollow. The peripheral shaft 1726 can be flexible. The peripheral shaft 1726 extends from the motor 1708. The peripheral shaft 1726 drives the downstream rotor or impeller 1712. The core shaft 1720 extends from the motor 1706. The core shaft 1720 can extend through the peripheral shaft 1726. The peripheral shaft 1726 and the core shaft 1720 extend from the sealed coupling on the upstream proximal side of the motor 1708. The peripheral shaft 1726 and the core shaft 1720 can be bi-flex shafts (where bi-flex here means both shafts are flexible).

[0523] FIGS. 160A-160E illustrate the device assembled. The pump head can collapse into the catheter 1716. FIG. 160A illustrates the nose cone 1724, the tip extension 1722, the hourglass frame 1714, and the contra-rotating impellers 1710, 1712. FIG. 160B illustrates a side view of the catheter 1716 retracted such that the pump head is expanded. FIG. 160C illustrates a top view of the catheter 1716 retracted. FIG. 160D illustrates a side view of the catheter 1716 advanced over the pump head. The catheter 1716 can slide along the shaft sheath 1704. The shaft sheath 1704 can cover the core shaft 1720 and the peripheral shaft 1726. FIG. 160E illustrates a side view of the catheter 1716 retracted.

[0524] FIG. 161A-161C illustrate other views of the systems. FIG. 161A illustrates the core shaft 1720. The core shaft 1720 can be disposed within the peripheral shaft 1726. The peripheral shaft 1726 can cover or surround the core shaft 1720. The core shaft 1720 and the peripheral shaft 1726 can be coaxial. The core shaft 1720 and the peripheral shaft 1726 drive the contra-rotating impellers as described herein. The core shaft 1720 and the peripheral shaft 1726 can be disposed within the shaft sheath (also called shaft sleeve) 1704. The shaft sheath 1704 can be a sleeve that covers or surrounds the core shaft 1720 and the peripheral shaft 1726. The shaft sheath 1704 can be disposed within the catheter 1716. The catheter 1716 can cover or surround the shaft sheath 1704. The catheter 1716 is shown as light blue in these figures. The dark blue shaft sheath 1704 is inside the catheter 1716.

[0525] FIG. 161B illustrates the gravity-fed or pressure bags containing biocompatible flushing or biocompatible lubricant fluid. The bags can be connected to the Luer connections 1736, 1738, 1740. The bags can be used to provide biocompatible flushing liquid between the rotating parts, as described herein. The bags can be filled with a biocompatible fluid, such as air, gas or liquid. The fluid can seal the space between the catheter 1716 and the shaft sheath 1704. The fluid can seal the space between the shaft sheath 1704 and the peripheral shaft 1726. The fluid can seal the space between the peripheral shaft 1726 and the core shaft 1720. While bags are shown, any fluid container or vessel can be connected to the Luer connections 1736, 1738, 1740. In some embodiments, the three bags can be simplified into a common fluid supply from one bag. The Luer connections 1736, 1738, 1740 can be connected to one or more fluid sources. The Luer connections 1736, 1738, 1740 can be connected to the same fluid source, such as one bag, container or vessel. The Luer connections 1736, 1738, 1740 can be connected to different fluid sources, such as separate bags, containers, or vessels. In some embodiments, the three gravity bags may be separate. In some embodiments, the three gravity bags may all be collapsed into one gravity bag feeding the inlets of three fluid paths F1i, F2i and F3i. The catheter introducer flush port 1741 for F4i and the air bladder 1743 behind it are shown in FIG. 158A, which are similar to 1740 for F3i and the Luer connections 1742 for the air bladder on the catheter 1716.

[0526] FIG. 161C illustrates the Luer connections 1736, 1738, 1740, 1742 relative to the other components of the system. The Luer connection 1736 can be a flushing or lubricant port for the space between the core shaft and peripheral shaft, and it is called the biflex flushing port. The Luer connection 1736 can be disposed between the motors 1706, 1708. The Luer connection 1736 can supply fluid to the space between the core shaft 1720 and the peripheral shaft 1726. The coupling for the solid core shaft 1720 is shown. The coupling can be disposed between the motor 1706 and the Luer connection 1736. The Luer connection 1736 can be disposed between the motors 1706, 1708. The Luer connection 1738 can be a flushing or lubricant port for the space between the peripheral shaft and the shaft sleeve, and it is called the sleeve flushing port. The Luer connection 1738 can supply fluid to the space between the peripheral shaft 1726 and the shaft sheath 1704. The Luer connection 1738 can be disposed between the motor 1708 and the catheter 1716. The Luer connection 1740 can be a flushing or lubricant port for the space between the shaft sleeve and catheter, and it is called the catheter flushing port. The Luer connection 1740 can supply fluid to the space between the shaft sheath 1704 and the catheter 1716. The Luer connection 1740 can be connected to the catheter 1716. The Luer connection 1742 can be a port for air or a biocompatible fluid. The Luer connection 1742 can be connected to a syringe. The Luer connection 1742 can be for an inflatable sealing arrangement. The Luer connection 1742 can be connected to the catheter 1716. The Luer connections 1736, 1738, 1740 can be used to introduce fluid between rotating components, or between stationary and rotating components. The Luer connection 1742 can be used to expand a sack or bladder at the distal end of the catheter 1716 to seal the space between the catheter 1716 and the shaft sheath 1704. The Luer connections 1736, 1738, 1740 can introduce any biocompatible flushing or lubricant fluid. The Luer connection 1742 can introduce any inflation medium.

[0527] FIGS. 162 and 163 illustrate a motor frame 1752. The motor frame 1752 supports the two co-axial contra-rotating motors 1706, 1708. The motors 1706, 1708 are coaxial. The 1706 is downstream of 1708. The motor frame 1752 can hold the motors 1706, 1708 in a fixed relationship.

[0528] FIG. 163 illustrates the motor frame 1752 and the motors 1706, 1708. The motor 1708 connects to the peripheral shaft 1726, which connects to the downstream impeller 1712. The motor 1708 can include a hollow motor shaft. The hollow motor shaft of the motor 1708 can align with the peripheral shaft 1726. The hollow motor shaft of the motor 1708 can align with the peripheral shaft 1726 via a sealed mechanical coupling. The hollow motor shaft can allow the core shaft 1720 to extend through the motor 1708. The motor 1708 can be closer to the patient. The motor 1708 is to the left side in this figure. The motor 1706 connects to core shaft 1720, which connects to the upstream impeller 1710. The motor 1706 can include a solid motor shaft. The solid motor shaft of the motor 1706 can align with the core shaft 1720. The solid motor shaft of the motor 1706 can align with the core shaft 1720 via a mechanical coupling. The motor 1706 can be further away from the patient. The motor 1706 is to the right side in this figure. The motors 1706, 1708 can be mounted to the motor frame 1752. The motor frame 1752 can be a supporting frame. The motor shafts of the motors 1706, 1708 are aligned coaxially in the motor frame 1752. The motors 1706, 1708 can be secured to the motor frame 1752 with one or more mechanical fasteners, such as bolts.

[0529] FIGS. 164A-164B illustrates a system with one or more intracorporeal motors 1754, 1756. FIG. 164A illustrates two intracorporeal motors 1754, 1756. The intracorporeal motors 1754, 1756 can be contra-rotating. The intracorporeal motors 1754, 1756 can include any features described herein. The intracorporeal motor 1754 can be connected to the core shaft 1720. The intracorporeal motor 1754 can have any features of the motor 1706. The intracorporeal motor 1754 can include any coupling arrangement to drive the core shaft 1720. The intracorporeal motor 1756 can be connected to the peripheral shaft 1726. The intracorporeal motor 1756 can have any features of the motor 1708. The intracorporeal motor 1756 can include any coupling arrangement to drive the peripheral shaft 1726. The intracorporeal motors 1754, 1756 can be for intracorporeal placement. The catheter 1716 can move upstream over the motors 1754, 1756. The catheter 1716 can move upstream to collapse the pump head. The intracorporeal motors 1754, 1756 can be supplied with an electric line. The electric line can extend to the intracorporeal motors 1754, 1756 within the patient. The electric line can include a skin insertion point. The electric line can include a supporting strand. The supporting strand can enable pushing the catheter 1716 forward. The supporting strand can facilitate pump-head collapsing by the catheter 1716. FIG. 164A includes contra-rotating motors with intracorporeal placement.

[0530] FIG. 164B illustrates the intracorporeal motor 1754 and an extracorporeal motor 1706. The motors 1754, 1706 can be contra-rotating. The intracorporeal motors 1754, 1706 can include any features described herein. The intracorporeal motor 1754 can be connected to the peripheral shaft 1726. The intracorporeal motor 1754 can have any features of the motor 1708. The intracorporeal motor 1754 can include any coupling arrangement to drive the peripheral shaft 1726. The motor 1706 can be connected to the core shaft 1720. The motor 1706 can include any coupling arrangement to drive the core shaft 1720. The motor 1706 can be for extracorporeal placement. The catheter 1716 can move upstream over the motor 1754. The catheter 1716 can move upstream to collapse the pump head. The intracorporeal motor 1754 can be supplied with an electric line. The electric line can extend to the intracorporeal motor 1754 within the patient. FIG. 164B includes the motor 1706 extracorporeal and the motor 1754 intracorporeal.

[0531] FIG. 165 illustrates an example of an impeller located in a shroud. Axial impellers can include a shroud, which is also called a duct. Axial impellers are more frequently unshrouded. FIG. 165 illustrates a marine propeller. The propeller includes a shroud secured on a stationary center body via shroud-supporting struts. Shrouded propellers may improve efficiency. Shrouded propellers are often used in marine propulsion.

[0532] In some embodiments, the impellers 1710, 1712 may be unshrouded, by removing the hourglass frame 1714. In some embodiments, the blades 1710, 1712 are shrouded (or ducted) by the hourglass frame 1714. The waist of the hourglass frame 1714 introduces a duct around the contra-rotating impellers 1710, 1712. The waist of the hourglass frame 1714 can enable one-size fits-all blood vessels. The waist of the hourglass frame 1714 can provide a fixed diameter shroud or duct at the waist. The waist of the hourglass frame 1714 can be sized in relation to the contra-rotating impellers 1710, 1712. The waist of the hourglass frame 1714 can also increases pump efficiency by minimizing backflow from downstream to upstream via optimizing the gap between impeller tip and shroud. Too small a gap increases hemolysis in the narrow passage, and too big a gap results in too much regurgitant flow. The waist of the hourglass frame 1714 or the shroud can also protect the blood vessel from coming to contact with the tips of the rotating blades of impellers 1710, 1712. The waist of the hourglass frame 1714 can have many advantages as described herein.

[0533] FIGS. 166A-166B illustrate examples of propellers, also called impellers. FIG. 166A illustrates an example of a shrouded propeller. FIG. 166B illustrates an example of an unshrouded propeller. The propellers can be used for a wide variety of applications.

[0534] FIGS. 167A-167D illustrate components of the pump head 1800. The pump head 1800 can include the hourglass frame 1714. The hourglass frame 1714 can include the inlet 1766. The hourglass frame 1714 can include the waist 1768. The hourglass frame 1714 can include the diffuser 1770. The inlet 1766, the waist 1768, and the diffuser 1770 can be joined together. FIG. 167A illustrates the inlet 1766. FIG. 167B illustrates the waist 1768. FIG. 167C illustrates the diffuser 1770. FIG. 167D illustrates the waist 1768.

[0535] The pump head 1800 can include supporting struts 1760, 1762, 1764. The supporting struts 1760 can extend to and be integrally formed with a nitinol tube 1761. The nitinol tube 1761 can be surround by a sleeve of the shaft holders 1730. The supporting struts 1762 can extend to and be integrally formed with a nitinol tube 1763. The nitinol tube 1763 can be surround by a sleeve of the shaft holders 1732. The supporting struts 1764 can extend to and be integrally formed with a nitinol tube 1765. The nitinol tube 1765 can be surround by a sleeve of the shaft holders 1734. The shaft holders 1730, 1732, 1734 can be any material, such as a polymer or PTFE. The supporting struts 1760, 1762, 1764 are used to secure the hourglass frame 1714. The supporting struts 1760, 1762, 1764 are used to align the hourglass frame 1714 to the axis of the impellers 1710, 1712. The supporting struts 1760, 1762, 1764 are used to align the hourglass frame 1714 with shafts 1720, 1726. The supporting struts 1760, 1762, 1764 are used to align hourglass frame 1714 relative to the impellers 1710, 1712. The supporting struts 1760, 1762, 1764 are used to align hourglass frame 1714 via the shaft holders 1730, 1732, 1734. The supporting struts 1760, 1762, 1764 are used to secure the hourglass frame 1714 to be aligned to the axis of the impellers 1710, 1712 and the shafts 1720, 1726 via shaft holders 1730, 1732, 1734. The shaft holders 1730, 1732, 1734 can be journal bearings. The shaft holders 1730, 1732, 1734 can be any type of bearing. The shaft holders 1730, 1732, 1734 can each be a two-piece assembly made of any biocompatible material, such as PTFE, in a manner to include in it the nitinol tubes 1761, 1763, 1765. An example is shown in FIG. 169D for shaft holder 1734.

[0536] The supporting struts 1760, 1762 for the waist 1768 of the hourglass frame 1714 converge to cylindrical shapes. The waist 1768 can have a generally cylindrical shape. The waist 1768 can have a generally constant diameter. The waist 1768 can have a diameter defined in relation to the diameter of the impellers 1710, 1712. The waist 1768 can define a gap between the hourglass frame 1714 and the tip of the impellers 1710, 1712. The gap can be 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.10 mm, 0.15 mm, 0.20 mm, 0.25 mm, 0.30 mm, 0.35 mm, 0.40 mm, 0.45 mm, 0.50 mm, 0.55 mm, 0.60 mm, 0.65 mm, 0.70 mm, 0.75 mm, 0.80 mm, 0.85 mm, 0.90 mm, 0.95 mm, 1 mm, 1.05 mm, 1.10 mm, 1.15 mm, 1.20 mm, 1.25 mm, 1.30 mm, 1.35 mm, 1.40 mm, 1.45 mm, 1.50 mm, 1.55 mm, 1.60 mm, 1.65 mm, 1.70 mm, 1.75 mm, 1.80 mm, 1.85 mm, 1.90 mm, 1.95 mm, 2 mm, or any of the foregoing values. In some embodiments, the nominal value of the gap will be around 0.5 mm. Smaller gaps may increase hemolysis. Larger gaps may increases backflow and reduces pump efficiency. Shaft vibration may require a larger gap.

[0537] The supporting struts 1760 including tube 1761 can connect to the shaft holders 1730. The supporting struts 1760 and the shaft holder 1730 can be upstream of the impellers 1710, 1712. The supporting struts 1762 including tube 1763 can connect to the shaft holders 1732. The supporting struts 1762 and the shaft holder 1732 can be downstream of the impellers 1710, 1712. The supporting struts 1760, supporting struts 1762 can be made from the same Nitinol tube as the waist 1768. The tubes 1761, 1763 can be made from the same Nitinol tube as the waist 1768. The tubes 1761, 1763 can be axially split. The tubes 1761, 1763 can be split axially for easier assembly and disassembly of the device. In other embodiments, the tubes 1761, 1763 are not split axially.

[0538] The supporting struts 1760, 1762 and the tubes 1761, 1763 can be made from the same Nitinol tube as the expanded waist 1768 of the hourglass frame 1714. In other embodiments, the supporting struts 1760, 1762 can be made from a different material or mesh as the expanded waist 1768 of the hourglass frame 1714. The supporting struts 1760, 1762 can have the same mesh size as the expanded waist 1768. The supporting struts 1760, 1762 can have a different mesh size as the expanded waist 1768. The supporting struts 1760, 1762 can have a shorter or longer axial length than the expanded waist 1768. The supporting struts 1760, 1762 can include a plurality of longitudinally extending struts. The supporting struts 1760, 1762 can be axially aligned.

[0539] The supporting struts 1760, 1762 can converge at the tubes 1761, 1763. The tubes 1761, 1763 can be surrounded by the shaft holders 1730, 1732. The shaft holders 1730, 1732 can include or be sleeves that surround the tubes 1761, 1763 that form the ends of the struts 1760, 1762. The shaft holders 1730, 1732 can be radial bearings that slide along the shaft of the device. The supporting struts 1760, 1762 and tubes 1761, 1763 are secured circumferentially with sleeves of the shaft holders 1730, 1732. The sleeves of the shaft holders 1730, 1732 surround the supporting struts 1760, 1762 and tubes 1761, 1763. The shaft holders 1730, 1732 can be any type of bearings. The shaft holders 1730, 1732 can slide along the shaft to collapse the pump head 1800. The tubes 1761, 1763 can be surrounded by sleeves of the shaft holders 1730, 1732, possibly with internally coated surfaces for lubricity, making them act like journal bearings.

[0540] The supporting struts 1764 and tube 1765 can be made from the same Nitinol tube as the expanded diffuser 1770 of the hourglass frame 1714. In other embodiments, the supporting struts 1764 can be made from a different material or mesh size as the expanded diffuser 1770 of the hourglass frame 1714. The supporting struts 1764 can have the same mesh size as the diffuser 1770. The supporting struts 1764 can have a different mesh size from the expanded diffuser 1770. The supporting struts 1764 can have a shorter or longer axial length than the diffuser 1770. The supporting struts 1764 can include a plurality of longitudinally extending struts. The supporting struts 1764 can be axially aligned. The supporting struts 1764 for the diffuser 1770 can converge to cylindrical shape.

[0541] The shaft holder 1734 can have a similar structure as 1732. The shaft holder 1734 can be a sleeve that surrounds the tube 1765. The shaft holder 1734 can be downstream of the diffuser 1770. The shaft holder 1734 can slide relative to shafts. In some embodiments, the shaft holder 1734 can function to secure the peripheral shaft 1726 inside the shaft sheath 1704. The supporting struts 1764 and tube 1765 can connect to the shaft holder 1734. The supporting struts 1764 and the shaft holder 1734 can be downstream. The supporting struts 1764 can be made from the same Nitinol tube as the expanded diffuser 1770. The tube 1765 can be made from the same Nitinol tube as the expanded diffuser 1770. The supporting struts 1764 and tube 1765 are secured circumferentially with the sleeve of the shaft holder 1734. The sleeve of the shaft holder 1734 surrounds the tube 1765 the supporting struts 1764. The shaft holder 1734 can be a radial bearing. In some embodiments, the shaft holder 1734 is attached to the tip of shaft sheath 1704, and thus it is held a fixed axial distance upstream of the motor 1708. In other embodiments, the shaft holder 1734 can slide along the shaft to collapse the diffuser 1770. The shaft holder 1734 can be bearings of any type. The shaft holder 1734 can be a journal bearing with internally-coated surfaces for lubricity. The shaft holders 1730, 1732, 1734 can have similar configurations. The shaft holders 1730, 1732, 1734 can have different configurations. The shaft holders 1730, 1732, 1734 can comprise the same material. The shaft holders 1730, 1732, 1734 can comprise different materials. The shaft holders 1730, 1732, 1734 can be sleeves that surround the tubes 1761, 1763, 1765.

[0542] In collapsing the device, and with the shaft holder 1734 at a set axial distance from the motor 1708, as the catheter 1716 is advanced upstream in relation to the hourglass frame 1714. The tip extension 1722, inside the nose cone 1724 holds the core shaft 1720 in place axially. As a result, the catheter 1716 forces the diffuser 1770 starting from the supporting struts 1764 to collapse into the catheter 1716. Next, the collapsing diffuser 1770 perimeter forces the supporting struts of 1762 connected to shaft holder 1732 to collapse into the catheter 1716. Next the collapsing perimeter of the waist 1768 of the hourglass frame 1714 forces the supporting struts 1760 connected to shaft holder 1730 to collapse into the catheter 1716. Meanwhile, the radially-collapsing hourglass shape collapses the impeller blades 1710, 1712 into the hourglass frame 1714, which can slide into the catheter 1716. FIGS. 171A, 171B, and 171C shows the shaft holder 1734 in the same axial place, and the upstream end of the tip extension 1722 also in the same place axially, as the catheter forces the hourglass upstream starting from the diffuser 1770. The nose cone 1724 moves upstream, but the shaft holder 1734 and the tip extension 1722 of the core shaft 1720 stay put as the hourglass and the blades collapse upstream. During this collapse, the shaft holder 1730 and the shaft holder 1732 also move upstream, but the impellers 1710, 1712 are at set axial positions along the shafts 1720, 1726, and their hubs stay axially set in place while the blades 1758 collapse upstream.

[0543] The collapsed hourglass shape of the hourglass frame 1714 is longer than the open or expanded hourglass shape of the hourglass frame 1714. The axial length of components can be selected to accommodate this elongation during collapse without component interference. There may be a desire to minimize the axial length of the collapsed and of the fully open device to accommodate implantation and removal in collapsed state. Techniques to minimize these with the design of the nitinol mesh are described herein.

[0544] The hourglass frame 1714 can comprise a shape memory material. The hourglass frame 1714 can comprise Nitinol. The shape-memory alloy properties of Nitinol can be used to make the desired collapsible hourglass shape. The hourglass frame 1714 can be formed so that it fits into the one-size fits-all blood vessels. The hourglass frame 1714 can have a pre-defined waist 1768. The pre-defined waist 1768 can expand to the same diameter regardless of the blood vessel diameter. The inlet 1766 can expand to a wider diameter than the waist 1768. The inlet 1766 can expand to the vessel wall over a range of vessel diameters. The inlet 1766 can allow the single device 1700 to fit all or almost all vessels within the human vasculature. The diffuser 1770 can expand to the vessel wall over a range of vessel diameters. The diffuser 1770 can allow the single pump head 1800 to fit all or almost all vessels within the human vasculature.

[0545] The hourglass frame 1714 can be manufactured from three separate Nitinol tubes. The first section can be an upstream section. The first section can be a distal section. The upstream section can form the inlet 1766. The upstream section can be near the heart. FIG. 167A illustrates the first section. The second section can be a middle waist 1768. The second section can include the supporting struts 1760, 1762. The second section can surround the blades 1710, 1712. The second section can be cut to a shape that includes the waist section supporting struts 1760, 1762 and the journal shaft holders 1730, 1732. The shaft holders 1730 can be upstream of the waist 1768. The shaft holders 1732 can be downstream of the waist 1768. FIG. 167B illustrates the second section. The third section can be a downstream section. The third section can be an outlet. The third section can be a proximal section. The third section can be near the kidneys. The third section can be called the diffuser 1770. The third section can have the Nitinol tube cut to include the supporting struts 1764 for the diffuser 1770 and shaft holder 1734.

[0546] Other types of bearings like ball bearings, needle bearings, magnetic levitation bearings etc. can be utilized in place of the shaft holders 1730, 1732, 1734. In some embodiments, the supporting struts 1760, 1762, 1764 can be made integrally with segments of the hourglass frame 1714. In some embodiments, the shaft holders 1730, 1732, 1734 can be made integrally with segments of the hourglass frame 1714. The supporting struts 1760, 1762 and the shaft holders 1730, 1732, 1734 can be made integrally with segments of the hourglass frame 1714. The supporting struts 1760, 1762 can be made integrally with the waist 1768. The supporting struts 1764 can be made integrally with the diffuser 1770. The supporting struts 1764 can be made integrally with the outer runners of the shaft holders 1734. The contra rotating shafts 1720, 1726 and contra-rotating blades 1710, 1712 are mounted inside the hourglass frame 1714, as described herein.

[0547] The shape-memory alloy properties of nitinol are used to make the desired collapsible hourglass shape 1714 and blades 1710, 1712 inside it so that it fits into the one-size fits all blood vessels. The hourglass frame is manufactured from three separate nitinol tubes. The first nitinol tube includes the upstream (inlet 1766, distal, near the heart) section. The second nitinol tube includes the middle, waist 1768 section, which is cut to a shape that includes the waist section support struts 1760, 1762 and the shaft holders 1730 and 1732. The shaft holder 1730 is upstream and the shaft holder 1732 is downstream of the waist section. The third nitinol tube includes the downstream (outlet, proximal, near the kidneys) section of the hourglass frame is the diffuser 1770, and the nitinol tube is cut to include the supporting struts 1764 for the diffuser and shaft holder 1734. Bearings like ball bearings, needle bearings, magnetic levitation bearings etc. can be utilized in place of shaft holders 1730, 1732, 1734. In this embodiment the struts 1760, 1762, 1764 supporting the shaft holders are inserted in 1730, 1732, 1734 as shown elsewhere. The shaft holder 1730 is inserted inside the tip of the shaft sheath 1704 as described herein. The contra rotating shafts 1720, 1726 and contra-rotating blades 1710, 1712 are mounted inside the hourglass frame 1714 as described herein. The shaft holder 1734 is glued or bonded inside the tip of the shaft sleeve 1704 as described herein.

[0548] FIGS. 168A-168D illustrate the hourglass frame 1714. FIG. 168A illustrates the waist 1768 and the diffuser 1770. FIGS. 168B-168D illustrates the waist 1768 and the inlet 1766. The inlet 1766, the waist 1768, and the diffuser 1770 can be joined together by eyelets. The eyelets can be welded together. In some embodiments, a thin metal rod is inserted through the eyelets of both segments and the parts are welded together. FIG. 168A illustrates the eyelets to be joined. The components can be joined with approximately equidistant gaps between the wire frame of the waist 1768, the diffuser 1770, and the joining section. In some embodiments, the components can be joined with not equidistant gaps between the wire frame of the waist 1768, the diffuser 1770, and the joining section.

[0549] FIGS. 168B-168D illustrate the inlet 1766 and the waist 1768 integral with the shaft holder 1730. The shaft holder 1730 can extend inside the inlet 1766 when the inlet 1766 and the waist 1768 are joined. The inlet 1766 can connect to the supporting struts 1760. The shaft holder 1732 can extend inside the diffuser 1770 when the diffuser 1770 and the waist 1768 are joined. The diffuser 1770 can connect to the supporting struts 1762. The inlet 1766 can be connected to the waist 1768. The inlet 1766 and the waist 1768 can expand and contract together. The inlet 1766 and the waist 1768 can be separate components. The waist 1768 can be connected to the diffuser 1770. The waist 1768 and the diffuser 1770 can expand and contract together.

[0550] FIGS. 169A-169K illustrate components of the system. FIG. 169A illustrate the hourglass frame 1714. The inlet 1766, the waist 1768, and the diffuser 1770 segments are joined together. FIG. 169B illustrates the inlet 1766 and the waist 1768 joined together. FIG. 169C illustrates the diffuser 1770 before joining the inlet 1766 and the waist 1768.

[0551] FIG. 169D illustrates the sleeve of shaft holder 1734. The shaft holder 1734 can surround the tube 1765 of the struts 1764. The peripheral shaft 1726 is shown. The catheter 1716 is shown. The tip of the shaft sheath 1704 has narrower inner diameter and wider outer diameter than the rest of the length of the shaft sheath 1704, forming the shaft holder 1734 and surrounding the nitinol tube 1765. This may be achieved by having two inserts bonded or glued to the tip of the cylindrical shaft sheath 1704. The nitinol tube 1765 is surrounded by the teal/blue sheath tips of shaft holder 1734. The shaft holder 1734 can be equipped with interior and exterior groves respectively. These teal/blue sheaths of the shaft holder 1734 can be bonded to or made integral with shaft sheath 1704 in one piece, or made of bonded pieces, integral sleeves with inner and outer grooves that surround nitinol tube 1765. The grooves can be used to control the flow rate and direction of flow of the lubricant/flushing between concentric components. For collapsing, the shafts 1720, 1726 and shaft sheath 1704 are held stationary, and the catheter 1716 is advanced upstream, engaging the support struts 1764 of the diffuser 1770. The catheter 1716 collapses the pump head 1800 radially from the diffuser 1770 to the waist 1768 to the inlet 1766, while the shaft holders 1730, 1732 move along the shafts as described herein. The blades are engaged and folded by the collapsing waist.

[0552] FIG. 169E illustrates the shaft holder 1732. FIG. 169F illustrates the nitinol shaft holder 1732 and the supporting struts 1762 and tube 1763. The tube 1763 can embedded in the green sheath of the shaft holder 1732, which may be made of PTFE and has interior grooves. The downstream supporting struts 1762 of the waist 1768 end in cylindrical nitinol tube 1763 which can be embedded or glued into the green sleeve surrounding the shaft holder 1732. The peripheral shaft 1726 can extend through the shaft holder 1732. The core shaft 1720 can be disposed within the peripheral shaft 1726. The slot 1728 in the peripheral shaft 1726 can admit flushing/lubricant from inside the peripheral shaft 1726 into the space inside the green sleeve of shaft holder 1732 and the peripheral shaft 1726. The green sleeve of the shaft holder 1732 can include circumferential grooves 1727. The grooves 1727 can be on an inside surface of the green sleeve of the shaft holder 1732. The grooves 1727 at the two ends of shaft holder 1732 can limit the amount of flush/lubricant needed. The grooves 1727 at the two ends of shaft holder 1732 can impart velocity to the outgoing flush. The shaft holder 1732 is further up the peripheral shaft 1726 (upstream) when the pump head 1800 is installed in smaller diameter blood vessel as shown in FIG. 171, and lower down the peripheral shaft 1726 (further downstream) when the pump head 1800 is in larger diameter blood vessel. The length of the shaft holder 1732 is at least as long as required to ensure the slot 1728 of peripheral shaft 1726 stays between the grooves 1727 of the shaft holder sleeve 1732 when the device 1700 is installed in various sizes of blood vessels.

[0553] FIG. 169G illustrates the nitinol shaft holder 1730 ending in a PTFE or similar material sleeve (green), which can be the same part as the nose cone 1724. The nose cone 1724 can be integral to the sleeve of shaft holder 1730. Inside shaft holder 1730, the perforated tip extension 1722 is rotating. The tip extension 1722 can be welded at the upstream tip, just near the tip, to the core shaft 1720. The tip extension 1722 admits flush/lubricant fluid from the perimeter of the core shaft 1720 to the space between the inner part of shaft holder 1730 and outer surface of the tip extension 1722. The tip extension 1722 can admit flush/lubricant fluid via the perforations on the tip extension 1722. The tip extension 1722 admits flush/lubricant fluid via a slot 1723 shown in FIG. 169I. The tip of the nose cone may have a curved segment at the upstream external tip to facilitate implantation through the vasculature. The core shaft 1720 via the tip extender 1722 can drive the upstream impeller 1710.

[0554] FIG. 169H illustrates the connection between the core shaft 1720 and the tip extension 1722. The core shaft 1720 and the tip extension 1722 can be bonded or welded at an upstream tip. The tip extension 1722 can have one or more slots to increase radial flexibility. The tip extension 1722 can include one or more slots to allow the flow of lubricant. The lubricant can flow between the tip extension 1722 which rotates and the stationary nose cone 1724. FIG. 169H includes a lubrication path in the nose cone 1724 which shows the core shaft 1720, peripheral perforated shaft, and yellow adapter at the tip to weld the core shaft 1720 to the perforated tube to make the tip extender 1722. FIG. 169H shows the core shaft 1720 shown in blue is welded to a peripheral perforated tube shown in light grey via tip insert shown in yellow, leaving lubricant/flush (dark grey) between the rotating core shaft 1720 and the peripheral perforated tube and the stationary nose cone 1724. The yellow tip insert accommodates the gap between the core shaft 1720 and tip extender 1722 while also providing a location to weld the three pieces together.

[0555] FIG. 169I illustrates the struts 1760 ending in cylindrical nitinol tube 1761, the shaft holder 1730, the tip extension 1722, and the nose cone 1724. The nose cone 1724 is integral to the green sleeve over shaft holder 1730. The grooves 1727 at the downstream end of the green sleeve of shaft holder 1730 limit the amount of flush/lubricant needed. The grooves 1727 can impart velocity to the outgoing flushing fluid. FIG. 169H illustrates the tip of the nose cone 1724. The core shaft 1720 and tip extension 1722 can be welded. The core shaft 1720 plus integral (welded) tip extension 1722 can reach the tip of the nose cone 1724 when the pump head 1800 is installed in a large diameter vessel. In a smaller diameter vessel, the core shaft 1720 plus integral (welded) tip extension 1722 is the same distance from the tip of the shaft sleeve 1704 and the upstream-impeller motor 1706, but the tip of the stationary nose cone 1724 moves further upstream, as shown in FIG. 171.

[0556] In FIG. 169I the tip extension 1722 can include the slot 1723. The slot 1723 in the tip extension 1722 can admit flushing/lubricant from inside the tip extension 1722 into the space between the shaft holder 1730 and the tip extension 1722. The slot 1723 of the tip extension 1722 is always in shaft holder 1730 from the largest to the smaller diameter vessel. In the unfolded device configuration, the tip extension 1722 reaches the inside tip of the nose cone 1724 when the pump head is installed in the largest diameter blood vessel. In the collapsed device, the core shaft 1720 plus tip extender 1722 is the same place axially, and the nose cone 1724 moves upstream. The solid tip of the nose cone 1724 may have a curve to facilitate implantation (FIG. 169A).

[0557] FIG. 169J illustrates the green sleeve of shaft holder 1730 surrounding the tube 1761 of the supporting struts 1760. FIG. 169K illustrates the green sleeve of shaft holder 1730 and its grooves. The upstream supporting struts 1760 and tube 1761 can be embedded or glued into the green sleeve of shaft holder 1730. The green sleeve of shaft holder 1730 can include circumferential grooves 1727. The grooves 1727 can be on an inside surface of the green sleeve of shaft holder 1730. The grooves 1727 at the ends of green sleeve of shaft holder 1730 can limit the amount of flushing needed. The grooves 1727 at the end of the green sleeve of shaft holder 1730 can impart velocity to the outgoing flushing liquid.

[0558] FIG. 170 illustrates the hourglass frame 1714 including the inlet 1766, the waist 1768, and the diffuser 1770. The inlet 1766 is upstream. The waist 1768 can be integral with shaft holders 1730, 1732. The waist 1768 can be integral with supporting struts 1760, 1762. The waist 1768 with integral shaft holders 1730 and 1732, and integral supporting struts 1760 between the shafts and shaft holder 1730, and supporting struts 1762 between the shafts and shaft holder 1732 can be integrally formed. The shaft holder 1730 can be upstream. The diffuser 1770 with integral shaft holder 1734 and integral supporting struts 1764 can be downstream.

[0559] In some embodiments, the shaft holder 1730 is downstream of the inlet 1766. In other embodiments, the inlet 1766 is downstream of the shaft holder 1730. The inlet 1766 and the waist 1768 are connected. The supporting struts 1760 extend inward to the shaft holder 1730. The supporting struts 1760 extend from the waist 1768. The supporting struts 1760 can be integrally formed with the waist 1768. The supporting struts 1760 extend to the shaft holder 1730. The supporting struts 1760 are disposed within the inlet 1766. The shaft holder 1730, the supporting struts 1760, and the waist 1768 can be integrally or monolithically formed. The shaft holder 1730 can include a sleeve or shaft to support the shaft holder.

[0560] The contra-rotating impellers 1710, 1712 can be downstream of the inlet 1766. The contra-rotating impellers 1710, 1712 can be downstream of the supporting struts 1760. The contra-rotating impellers 1710, 1712 can be downstream of the shaft holder 1730. The contra-rotating impellers 1710, 1712 can be within the waist 1768.

[0561] The waist 1768 and the diffuser 1770 are connected. The supporting struts 1762 extend inward to the shaft holder 1732. The supporting struts 1762 extend from the waist 1768. The supporting struts 1762 can be integrally formed with the waist 1768. The supporting struts 1762 extend to the shaft holder 1732. The supporting struts 1762 are disposed within the diffuser 1770. The shaft holder 1732 is disposed within the diffuser 1770. The supporting struts 1762 extend inward to the shaft holder 1732. The shaft holder 1732, the supporting struts 1762, and the waist 1768 can be integrally or monolithically formed. The shaft holder 1732 can include a sleeve or shaft to support the shaft holder.

[0562] The contra-rotating impellers 1710, 1712 can be upstream of the diffuser 1770. The contra-rotating impellers 1710, 1712 can be upstream of the supporting struts 1762. The contra-rotating impellers 1710, 1712 can be upstream of the shaft holder 1732.

[0563] The supporting struts 1764 extend inward to the shaft holder 1734. The supporting struts 1764 extend from the diffuser 1770. The supporting struts 1764 can be integrally formed with the diffuser 1770. The supporting struts 1764 extend to the shaft holder 1734. The shaft holder 1734, the supporting struts 1764, and the diffuser 1770 can be integrally or monolithically formed. The shaft holder 1734 can include a sleeve or shaft to support the shaft holder.

[0564] The shaft holders 1730, 1732 can slide relative to the shafts 1720, 1726. The shaft holder 1734 is affixed to the tip of shaft sheath 1704. The upstream tip of shaft sheath 1704 can surround the shaft holder 1734. The shafts 1720, 1726 can be disposed within the shaft sheath 1704. The core shaft 1720 can be disposed within the peripheral shaft 1726. The peripheral shaft 1726 can drive the downstream impeller 1712. The core shaft 1720 can drive the upstream impeller 1710. The core shaft 1720 can extend to the tip extension 1722. The tip extension 1722 can be covered with the nose cone 1724.

[0565] The catheter 1716 can be pulled back to expand the hourglass frame 1714. The inlet 1766 can expand first, the waist 1768 can expand next (which allows the impeller blades to unfold), and the diffuser 1770 can expand last. The shaft holders 1730, 1732 can slide relative to the shafts 1720, 1726 to radially expand and axially shorten the waist 1768. The shaft holders 1730, 1732 can slide relative to the shafts 1720, 1726 to accommodate the unfolding of the blades 1710, 1712. The shaft holders 1730 can slide relative to the shafts 1720, 1726 to radially expand and axially shorten the inlet 1766. The shaft holder 1734 is affixed to the tip of the shaft sheath and does not slide relative to the shafts 1720, 1726 as the pump head 1800 expands and collapses. The contra-rotating impellers 1710, 1712, the shafts 1720, 1726, the shaft sheath 1704, and the catheter 1716 are described herein.

[0566] The inlet 1766 is shown. The waist 1768 with integral shaft holders 1730, 1732 and integral support struts 1760 between the shafts and shaft holder 1730, and support struts 1762 between the shafts and shaft holder 1732 are shown. The diffuser 1770 with integral shaft holder 1734 and integral support struts 1764 between the shafts and shaft holder 1734 are shown. The contra-rotating impellers 1710, 1712 and shafts 1720, 1726, shaft sheath 1704 and catheter 1716 are described herein.

[0567] FIG. 171 illustrates the pump head 1800. The shaft holders 1730, 1732, 1734 are shown. The tip extension 1722 is shown. The tip extension 1722 is shown inside nose cone 1724. The tip extension 1722 remains at the same axial position in relation to diffuser shaft holder 1734 as the pump head 1800 is folded or unfolded. The upstream tip of the tip extension 1722 and the shaft holder 1734 are held in the same axial place via the core shaft 1720 in the vasculature as the pump head 1800 is folded or unfolded by the catheter 1716 moved up or down. When the pump head 1800 is collapsed the upstream tip of the nose cone slides upstream in relation to the tip extender, as illustrated in FIG. 171.

[0568] In some embodiments, when collapsing the device into a catheter, the shaft holder 1734 and the tip of the tip extension 1722 inside the nose cone 1224 stay fixed in length in relation to the extra-corporeal motors 1706, 1708. The shaft holders 1730, 1732 move upstream during the collapsing process, and the blades 1710, 1712 fold upstream. The smaller the catheter diameter in which the hourglass frame 1714 is collapsed, the further upstream moves the collapsed upstream tip of the inlet 1766 and the shaft holders 1730, 1732. As the pump head 1800 collapses, the distal tip of the tip extension 1722 stays in axial position, while shaft holder 1730 and the nose cone 1724 move upstream. Various alternative folding configurations are contemplated. The impellers 1710, 1712 fold upstream in the embodiment described so far, but may fold upstream or downstream in alternative embodiments, as described herein in FIGS. 172 to 175.

[0569] FIG. 171A-171C illustrate the collapsing of the device. In some embodiments, when collapsing the device into the catheter, the shaft holder 1734 can stay fixed. The shaft holders 1730 and 1732 can move upstream during the collapsing process. The impellers 1710, 1712 can fold upstream. The upstream tip of the inlet 1766 is shown at the bottom in the figures. The shaft holders 1732 and 1730 move further upstream the smaller the catheter diameter. The shaft holders 1730, 1732 move closer to the tip, the smaller the catheter diameter. FIG. 171C illustrates the device collapsed for a smaller diameter catheter. FIG. 171B illustrates the device collapsed for a larger diameter catheter. The compressed length for smaller diameter catheters is greater than the compressed length for larger diameter catheters. The device lengthens by moving the shaft holders 1730, 1732 closer to the tip. The device lengthens by moving the inlet 1766 closer to the tip. The device axially lengthens in order to radially reduce in diameter. The greater the reduction in diameter, the longer the hourglass frame 1714 in the compressed configuration.

[0570] FIG. 172A-172C illustrates the folding of the device in the case where shaft holder 1734 is stationary, and in collapsing the pump head shaft holders 1730 and 1732 move away from each other, while the blades fold upstream. FIG. 172 C shows the device in the catheter. FIG. 172 B shows the device unfolded in a blood vessel size that has the same diameter as the waist 1714. FIG. 172A shows the device unfolded in a larger diameter vessel than the diameter of the waist 1714. The shaft holder 1734 can be fixed. The shaft holder 1730, 1732 can slide upstream. The impellers 1710, 1712 can collapse upstream. The hourglass frame 1714 including the inlet 1766, the waist 1768, and the diffuser 1770 can collapse upstream. The hourglass frame 1714 can axially lengthen upstream. The hourglass frame 1714 can axially lengthen from the fixed shaft holder 1734. The nose cone 1724 advances over the tip extension 1722. The nose cone 1724 can slide upstream. The nose cone 1724 can slide along the tip extension 1722 to accommodate the axially lengthening of the hourglass frame 1714. The hourglass frame 1714 can axially lengthen and radially compress. The hourglass frame 1714 can facilitate folding of the impellers 1710, 1712 The catheter 1716 can move upward over the shaft holder 1734. The catheter 1716 can move upward over the diffuser 1770. The catheter 1716 can move upward over the shaft holder 1732. The catheter 1716 can move upward over the waist 1768 and the impellers 1710, 1712. The catheter 1716 can move upward over the shaft holder 1732. The catheter 1716 can move upward over the inlet 1766. The catheter 1716 can move upward toward the nose cone 1724. The catheter 1716 can move over the collapsed hourglass frame 1714. The catheter 1716 can move over the folded impellers 1710, 1712.

[0571] The device can include struts 1790, 1792, 1794. The struts 1790, 1792, 1794 can connect to the shaft holders 1730, 1732, 1734. The struts 1790, 1792, 1794 can be integrally formed with the shaft holders 1730, 1732, 1734. The struts 1790 can connect the upstream end of the waist 1768 to the shaft holder 1730. The struts 1790 can connect the downstream end of the inlet 1766 to the shaft holder 1730. The struts 1792 can connect the downstream end of the waist 1768 to the shaft holder 1732. The struts 1792 can connect the upstream end of the diffuser 1770 to the shaft holder 1732. The struts 1794 can connect the downstream end of the diffuser 1770 to the shaft holder 1734. The struts 1792, 1794 can point downward. The struts 1790 point upward. The device can include one or more struts 1790, 1792, 1794.

[0572] The tip of tip extension 1722 and the shaft holder 1734 are held in place via the shaft in the vasculature. The catheter 1716 is moved up or down. The shaft holder 1734 is fixed. The impellers 1710, 1712 and the hourglass frame 1714 collapse upstream, and the catheter 1716 moves over the shaft holder 1734. The axial distance between the tip extension 1722 and the shaft holder 1734 is fixed. The nose cone 1724 moves further upstream as the pump head 1800 collapses from maximum vasculature diameter (left); to minimum vasculature diameter equal to waist diameter (middle); to catheter diameter (right).

[0573] FIGS. 173A-173C illustrate an alternative configuration. In this case the upstream tip of the tip extender is always at the upstream tip of the nose cone, as the catheter advances the downstream tip of shaft holder 1734 moves inside the catheter, shaft holder 1732 also moves downstream, and the impellers and the hourglass 1714 fold downstream. The shaft holder 1730 can be fixed. The blades 1710, 1712 can collapse downstream. The hourglass frame 1714 including the inlet 1766, the waist 1768, and the diffuser 1770 can collapse downstream. The catheter 1716 can advance over the shaft holder 1734. The shaft holder 1734 can be pulled into the catheter as the catheter advances. The catheter 1716 can advance over the collapsed hourglass frame 1714. The catheter 1716 can facilitate collapse of the hourglass frame 1714. The catheter 1716 can advance over the folded blades 1710, 1712.

[0574] FIG. 173A illustrates the device expanded within a larger diameter vessel. The hourglass frame 1714 can expand to fit the vessel. The inlet 1766 can expand to a larger diameter than the waist 1768. The diffuser 1770 can expand to a larger diameter than the waist 1768. The inlet 1766 and the diffuser 1770 can expand to the same diameter. The inlet 1766 and the diffuser 1770 can expand to the diameter of the vessel. The inlet 1766 can have the same length as the waist 1768. The inlet 1766 can have a different length as the waist 1768. The diffuser 1770 can have a greater length than the inlet 1766. The diffuser 1770 can have a greater length than the waist 1768.

[0575] FIG. 173B illustrates the device expanded within a smaller diameter vessel, equal to the waist diameter. The hourglass frame 1714 can expand to fit the vessel. The inlet 1766 can expand to a slightly larger or equal diameter as the waist 1768. The diffuser 1770 can expand to a slightly larger or equal diameter than the waist 1768. The inlet 1766 and the diffuser 1770 can expand to the same diameter. The inlet 1766 and the diffuser 1770 can expand to the diameter of the vessel. The inlet 1766 can axially lengthen for smaller diameter vessels compared with FIG. 173A The diffuser 1770 can axially lengthen for smaller diameter vessels compared with FIG. 173A. The waist 1768 can have the same expanded diameter for any vessel diameter. The waist 1768 can have the same expanded length for any vessel diameter. FIG. 173B illustrates the shaft holders 1732, 1734 sliding down to accommodate the axial lengthening. The shaft holder 1730 can be fixed. The hourglass frame 1714 can become less hourglass in shape to accommodate differently sized vessels. The frame can become more cylindrical. The hourglass frame 1714 can be utilized with vessels having a diameter equal to the expanded diameter of the waist 1768. The hourglass frame 1714 can be utilized with vessels having a diameter greater than the expanded diameter of the waist 1768, due in part to the expansion of the inlet 1766 and/or the diffuser 1770.

[0576] FIG. 173C illustrates the device collapsed. The hourglass frame 1714 can axially lengthen to radially collapse. The inlet 1766 can axially lengthen compared with FIGS. 173A and 173B. The diffuser 1770 can axially lengthen compared with FIGS. 173A and 173B. The waist 1768 can axially lengthen compared with FIGS. 173A and 173B. FIG. 173C illustrates the shaft holders 1732, 1734 sliding down. The shaft holder 1730 is stationary. The supporting struts 1760, 1762 can be considered centralizers. The blades 1710, 1712 can be configured to fold downward.

[0577] FIG. 173C illustrates the radial compression of the hourglass frame 1714. The hourglass frame 1714 can radially compress and axially lengthen. The frame can become more cylindrical in the collapsed state. The inlet 1766 can become more cylindrical. The diffuser 1770 can become more cylindrical. The shaft holder 1734 can be received in the catheter 1716. The shaft holders 1732, 1734 can slide down relative to the shafts 1720, 1726. The shaft holder 1734 can be pulled downward. The catheter 1716 can be slid upward. The shaft holder 1734 can be connected to the diffuser 1770 which is connected to the waist 1768 and the inlet 1766. By pulling the shaft holder 1734, the hourglass frame 1714 can collapse, thereby collapsing the blades 1710, 1712. The shaft holder 1734 and at least a portion of the diffuser 1770 can be received in the catheter 1716. The catheter 1716 can be further advanced. The blades 1710, 1712 can be folded downward by the collapse of the hourglass frame 1714.

[0578] The vessel diameter can accommodate the expanded hourglass shape. The waist 1768 can be smaller in diameter than the vessel diameter as shown in FIG. 173A. FIG. 173B illustrates a vessel diameter the same as the waist 1768. The waist 1768 can correspond to the expanded diameter of the blades 1710, 1712. The waist 1768 can form a shroud. The inlet 1766 can be expanded to the vessel wall. The inlet 1766 can have the same or similar diameter as the waist 1768. The inlet 1766 can have a greater diameter than the waist 1768. The diffuser 1770 can be expanded to the vessel wall. The diffuser 1770 can have the same or similar diameter as the waist 1768. The diffuser 1770 can have a greater diameter than the waist 1768.

[0579] The hourglass frame 1714 can accommodate vessels over a range of diameters. The hourglass frame 1714 can allow the device to be one-size-fits-all. The inlet 1766 and/or the diffuser 1770 can expand to the vessel wall. The inlet 1766 and/or the diffuser 1770 can expand beyond the waist 1768. The waist 1768 can be constant for all vessel diameters. The waist 1768 can be determined based on the diameter of the blades 1710, 1712. The waist 1768 can expand to the vessel wall as shown in FIG. 173A. The waist 1768 can have a smaller diameter than the vessel wall, as shown in FIG. 173B.

[0580] The tip of tip extension 1722 and the shaft holder 1730 held in place via the shaft in the vasculature. The catheter 1716 can be moved up or down. The shaft holder 1730 slides into the catheter 1716 and the shaft holder 1732 moves downstream. The shaft holder 1730 is fixed. The shaft holder 1734 is pulled inside the catheter 1716 to collapse. The blades 1710, 1712 and the caging of the hourglass frame 1714 collapses downstream as the shaft holder 1734 is pulled into catheter 1716. FIG. 173A is shown at max vasculature hourglass shape, when vessel diameter is same as the waist in FIG. 173B, and collapsed into catheter in FIG. 173C.

[0581] FIGS. 174A-174C illustrate an alternative configuration. In this case the upstream struts of shaft holder 1730 are attached to the middle of the length of the inlet, the downstream struts of shaft holder 1732 are attached the middle of the length of the diffuser, shaft holder 1734 stays in place, and as the catheter is advanced upstream the pump head 1800 and the impellers fold upstream. The shaft holder 1734 can be fixed. The shaft holders 1730, 1732 can slide upstream. The blades 1710, 1712 can collapse upstream. The hourglass frame 1714 including the inlet 1766, the waist 1768, and the diffuser 1770 can collapse upstream. The hourglass frame 1714 can axially lengthen. The hourglass frame 1714 can axially lengthen from the fixed shaft holder 1734. The nose cone 1724 advances over the tip extension 1722. The catheter 1716 can advance upstream. The blades 1710, 1712 and the hourglass frame 1714 collapses upstream as the catheter 1716 advances upstream.

[0582] The device can include centralizers 1790, 1792, 1794. The centralizers 1790, 1792, 1794 can connect to the corresponding shaft holders 1730, 1732, 1734. The centralizer 1790 can connect between upstream end and downstream end of the inlet 1766. The centralizer 1790 is connected to the mid-wall of the inlet 1766. The centralizer 1790 can connect the inlet 1766 to the shaft holder 1730. The centralizer 1792 can connect between upstream end and downstream end of the diffuser 1770. The centralizer 1792 is connected to the mid-wall of the diffuser 1770. The centralizer 1792 can connect the diffuser 1770 to the shaft holder 1732. The centralizer 1794 is connected to the downstream end of the diffuser 1770. The centralizer 1794 can connect the diffuser 1770 to the shaft holder 1734. The centralizers 1790, 1794 can point downward. The centralizer 1792 point upward. The upstream centralizer 1790 can fold upstream. The downstream centralizer 1792 can fold downstream. The upstream centralizer 1790 and the downstream centralizer 1792 collapse in opposite directions.

[0583] The tip of the tip extension 1722 and the shaft holder 1734 are held in place via the shaft in the vasculature, while the device is also held in place via the wide diameters of the inlet and diffuser sections against the vasculature. The catheter 1716 can be moved up or down. The blades 1710, 1712 and the caging of the hourglass frame 1714 collapses upstream as catheter 1716 advances upstream. The upstream centralizers fold upstream. The downstream centralizes fold downstream. The centralizes 1790, 1792, 1794 are connected between upstream and downstream ends of inlet 1766 and the diffuser 1770 (mid wall of each component), collapsing in opposing directions.

[0584] FIGS. 175A-175C illustrate an alternative configuration. In this case the upstream struts of shaft holder 1730 are attached to the upstream tip of the inlet, the downstream struts of shaft holder 1732 are attached to the upstream tip of the diffuser, shaft holder 1734 stays in place, and as the catheter is advanced upstream the pump head 1800 and the impellers fold upstream. The shaft holder 1734 can be fixed. The blades 1710, 1712 can collapse upstream. The hourglass frame 1714 including the inlet 1766, the waist 1768, and the diffuser 1770 can collapse upstream. The catheter 1716 can advance upstream. The blades 1710, 1712 and the hourglass frame 1714 collapses upstream as the catheter 1716 advances upstream. The device can include centralizers 1790, 1792, 1794. The centralizers 1790, 1792, 1794 can connect to the corresponding shaft holders 1730, 1732, 1734. The centralizer 1790 can connect to the upstream end of the inlet 1766. The centralizer 1790 can connect the inlet 1766 to the shaft holder 1730. The centralizer 1792 can connect to upstream end of the diffuser 1770. The centralizer 1792 can connect the diffuser 1770 to the shaft holder 1732. The centralizer 1794 is connected to the downstream end of the diffuser 1770. The centralizer 1794 can connect the diffuser 1770 to the shaft holder 1734. The centralizers 1790, 1792, 1794 can point downward. The centralizers 1790, 1792, 1794 can fold downstream. The centralizers 1790, 1792, 1794 collapse in the same directions. The upstream centralizer 1790 can fold upstream. The downstream centralizer 1790 can fold downstream. The upstream supporting struts 1760 can be connected at an upstream end of the inlet 1766. The downstream supporting struts 1762 can be connected at an upstream end of the diffuser 1770. The upstream supporting struts 1760 and the downstream supporting struts 1762 collapse in the same direction.

[0585] The tip of tip extension 1722 and the shaft holder 1734 are held in place via the shaft in the vasculature. The catheter 1716 can be moved up or down. The blades 1710, 1712 and the caging of the hourglass frame 1714 collapses upstream as catheter 1716 advances upstream. The upstream centralizers fold upstream and are attached at upstream end of inlet 1766. The downstream centralizers fold downstream. The centralizers are all collapsing in the same direction.

[0586] FIGS. 176A-176B illustrate a technique to minimize the axial lengthening of the diffuser 1770 as the device collapses. The same technique can be used for the inlet 1766 and the waist 1768, or throughout the hourglass length. The diffuser 1770 can be connected to the waist 1768. The waist 1768 can be connected to the inlet 1766. FIG. 176A includes nearly uniform mesh of the diffuser 1770. FIG. 176B includes segments 1772 parallel to the diffuser centerline in the mesh of the diffuser. During collapse these segments in FIG. 176B do not change length, while the corresponding axial length of diffuser mesh in FIG. 176A would elongate. The length of the diffuser is L2. FIG. 176A does not include the segments 1772. The length of the diffuser is L1. The length of the diffuser 1770 without the segments 1772 is greater than the length of the diffuser 1770 with the segments 1772. The segments 1772 can reduce the length of the diffuser 1770 when the diffuser is collapsed. Techniques like this can be used to minimize the axial length of the collapsed components 1766, 1768, 1770, and of the overall hourglass section.

[0587] FIG. 177 illustrates an alternative configuration of the mesh (lattice) of the diffuser struts 1764. The same technique can be used for waist struts 1760 and 1762. The struts 1760 can be connected or formed with tube 1761. The struts 1762 can be connected or formed with tube 1763. The struts 1764 can be connected or formed with tube 1765. The mesh (lattice) of any struts can be the same or different from the corresponding section of the hourglass. The hourglass frame 1714 can include a mesh in which the space between any of the struts is defined. The space between any of the struts has as dense a lattice as the space on the perimeter of the hourglass. For instance, the space between supporting struts 1764 can have a dense lattice. The space between supporting struts 1764 can have the same lattice as another portion of the hourglass frame 1714. In some embodiments, the hourglass frame 1714 has a constant or consistent lattice. The diffuser 1770 can include the same lattice as the waist 1768. The waist 1768 can include the same lattice as the inlet 1766. The support struts 1760, 1762, 1764 of the shaft holder 1730, 1732, 1734 can have as dense a nitinol frame lattice as the spacing on the perimeter of the hourglass frame 1714. The concept is shown here on the struts 1764 of the shaft holder 1764 only. The supporting struts 1764 have the same lattice as the rest of the diffuser 1770.

[0588] FIG. 178 illustrates the hourglass frame 1714. In some embodiments, portions of the hourglass shape 1714 can be covered or coated with one or more biocompatible materials 1774. The inlet 1766 can be covered with the material 1774. The waist 1768 can be covered with the material 1774. The diffuser 1770 can be covered with the material 1774. In some embodiments, the entire length of the hourglass shape 1714 can be covered or coated with the material 1774. The material 1774 can be a biocompatible material. The material 1774 can assist perfusion. FIG. 178 illustrates the waist 1768 and the diffuser 1770 covered by the material 1774. Any portion of the hourglass frame 1714 may be covered by the material 1774. In some embodiments, the biocompatible coating or material 1774 disposed on the hourglass frame 1714 may be important in the waist 1768 and the diffuser 1770 to achieve the high pump performance. Having the whole of the inlet covered as shown in FIGS. 172-175, or partially covered as shown in FIG. 156C, also has corresponding fluid dynamic advantages.

[0589] The material 1774 can be used to implement fluid dynamic advantages. The material 1774 covering the waist 1768, or a portion thereof, can be used to make the impellers 1710, 1712 achieve the higher performance levels of shrouded impellers. The material 1774 can increase the fluid-dynamic efficiency of the blades 1710, 1712. Therefore, material 1774 can reduce device rpm. The material 1774 covering the diffuser 1770, or a portion thereof, can provide significant hydrodynamic advantages. The material 1774 covering the diffuser 1770 can straighten out the flow downstream, meaning to a large degree to realign the velocity vectors after the downstream impeller to the axial direction. With the waist 1768 and the diffuser 1770 covered by the material 1774 but the inlet 1766 not covered, the space between the hourglass frame 1714 and the blood vessel is perfused. Thus, the uncovered inlet 1766 can prevent covering of the spinal artery during operation. With openings 1776, the partially covered inlet, as shown in FIG. 156C, 179A, or 179B, combines the fluid dynamic advantages of a covered inlet with the side-artery perfusion requirement. The material 1774 can be a biocompatible cover. The material 1774 can be disposed the interior of the hourglass frame 1714. The material 1774 can be disposed on the exterior of the hourglass frame 1714. The material 1774 can be disposed on both sides, on the interior and exterior of the hourglass frame 1714. The material 1774 can have anti-thrombotic properties. The material 1774 can have drug-eluding properties.

[0590] The material 1774 can cover a portion of the waist 1768. The material 1774 can cover the portion of the waist 1768 near the impellers. In some embodiments, the material 1774 does not cover the supporting struts 1760. In some embodiments, the material 1774 does not cover the inlet 1766. In some embodiments, the material 1774 covers at least a portion of the supporting struts 1760. In some embodiments, the material 1774 covers at least a portion of the supporting struts 1762. The material 1774 can cover the diffuser 1770. The material 1774 can be continuous from the waist 1768 to the diffuser 1770. The material 1774 can be discontinuous from the waist 1768 to the diffuser 1770. The material 1774 can include one or more section. The material 1774 can extend circumferentially. In some embodiments, the material 1774 does not cover the supporting struts 1764. In some embodiments, the material 1774 does covers at least a portion of the supporting struts 1764. In some embodiments, the material 1774 extends to or near the tube 1765. In some embodiments, the material 1774 does not cover the shaft holders 1730, 1734. The shaft holder 1732 can be disposed within the hourglass frame 1714 covered by the material 1774. The material 1774 can form a sleeve. The material 1774 can include one or more sections. Each section can include the same material 1774. Each section can include a different material 1774. The material 1774 surrounding the waist 1768 can be different from the material surrounding the diffuser 1770. The material 1744 surrounding the waist 1768 can be the same as the material 1774 surrounding the diffuser 1770. The material 1774 can apply a compressive force on the hourglass frame 1714. The material 1774 can constrain the expansion of the waist 1768. The material 1774 can facilitate the constant diameter of the waist 1768 near the blades 1710, 1712.

[0591] In some embodiments, the material does not cover the intercostal and the spinal artery There can be fluid dynamic advantages of the covered diffuser 1770. In some embodiments, the hubs 1778 include slots. In some embodiments, the hubs 1778 include clips. In some embodiments, the hubs 1778 include features to facilitate manufacturing and coupling. The shaft holder shape is shown. Portions of the hourglass shape 1714 (or the whole length of the hourglass shape) is covered with biocompatible material 1774 to assist perfusion. In some embodiments, the waist 1768 and the diffuser 1770 are shown covered, but any portion of the hourglass frame 1714 may be covered, to implement fluid dynamic advantages. The waist 1768 cover is used to make the impellers 1710, 1712 shrouded, thus increasing their efficiency and reducing device rpm. The diffuser 1770 covering gives significant hydrodynamic advantages in straightening out the flow downstream. With the waist 1768 and diffuser 1770 covered but the inlet 1766 not covered, the space between the hourglass frame 1714 and the blood vessel is perfused, thus preventing covering of the intercostal and especially the spinal artery during operation. The biocompatible cover 1774 may be on the interior of the hourglass frame 1714, or the exterior, or both sides, and may have anti-thrombotic properties, or drug-eluding properties.

[0592] FIGS. 179A-179B illustrate another embodiment of the inlet 1766. Instead of the inlet 1766 being totally open, the inlet 1766 can be partially open. In some embodiments, portions of the hourglass shape 1714 can be covered or coated with the material 1774. The inlet 1766 can be covered with the material 1774. The inlet 1766 can be covered with a porous material, or a coating 1774 with openings 1776. The material 1774 can include one or more openings 1776. The material 1774 can include one opening, two openings, three openings, four openings, five openings, six openings, seven openings, eight openings, nine openings, ten openings, or any range of two of the foregoing values. The openings 1776 can be circumferentially spaced. The openings 1776 can be equally spaced. The openings 1776 can be unequally spaced. The openings 1776 can be circular, rounded, oval, or any shape. The openings 1776 can optimize flow patterns. The openings 1776 can optimize the hydrodynamic efficiency of the pump head. The openings 1776 can allow perfusion of the spinal artery. The inlet 1766 can be covered with the same material as the waist 1768 and/or the diffuser 1770. The inlet 1766 can be covered with a different material. In some embodiments, the flow openings 1776 via the sides of the inlet may also be important to perfuse the intercostal arteries, especially the spinal artery. The openings 1776 or holes in the biocompatible material can be in the inlet 1766. The openings 1776 or holes in the biocompatible material can be in the waist 1768. The openings 1776 or holes in the biocompatible material can be in the diffuser 1770. The openings 1776 or holes in the biocompatible material can be in the inlet 1766, the waist 1768, the diffuser 1770, or in any combination.

[0593] The shaft holders 1730, 1732, 1734 are shown. Instead of the inlet 1766 being totally open, it is partially open and partially closed, thus optimizing flow patterns at waist inlet and efficiency of the pumphead, but still allowing perfusion of the intercostal and spinal artery. The holes or openings 1776 in the biocompatible coating or material 1774 of the membrane, anywhere on the membrane, may be any shape, e.g. oval shown here, or rhombus-shaped following the nitinol wireframe as shown in FIG. 156C. The material 1774 can be coated with antithrombotic anticoagulant coating.

[0594] FIGS. 180A-180B illustrate another embodiment of the material 1774. The diffuser 1770 can be partially open with openings. In some embodiments, portions of the hourglass shape 1714 can be covered or coated with the material 1774. The diffuser 1770 can be covered with the material 1774. The diffuser 1770 can be covered with a porous material. The material 1777 can include openings 1776. The material 1774 can include one opening, two openings, three openings, four openings, five openings, six openings, seven openings, eight openings, nine openings, ten openings, or any range of the foregoing values. The openings 1776 can be circumferentially spaced. The openings 1776 can be equally or unequally spaced. The openings 1776 can be any shape. The openings 1776 of the inlet 1766 and the diffuser 1770 can align. The openings 1776 of the inlet 1766 and the diffuser 1770 can be the same or similar. The openings 1776 of the inlet 1766 and the diffuser 1770 can be offset or misaligned. The openings 1776 of the inlet 1766 and the diffuser 1770 can be different. The openings 1776 of the inlet 1766 and the diffuser 1770 can be different in one or more of size, shape, spacing, or dimension. The material 1774 can be continuous. In some embodiments, the material 1774 covering the waist 1768 does not include openings or pores. In other embodiments, the material 1774 covering the waist 1768 can include openings or pores. The material 1774 can extend axially from the inlet 1766 to the diffuser 1770. The supporting struts 1760, 1764 can be uncovered. Any part of the hourglass frame 1714 may be partially pervious. The openings 1776 can be any size or shape. The shaft holder 1730, 1732, 1734 are shown. The shaft holder 1730, 1732, 1734 can include slots. In some embodiments, the shaft holder 1730, 1732, 1734 include clips. In some embodiments, each shaft holder 1730, 1732, 1734 is made in two halves. In some embodiments, the shaft holder 1730, 1732, 1734 include features to facilitate manufacturing and coupling Any part of the hourglass frame 1714 may be partially pervious. The inlet 1766 and the diffuser 1770 are pervious. The openings 1776 of the material 1774 can be as large as shown or with smaller openings.

[0595] FIG. 181A-181C illustrates an embodiment of one typical impeller with blades designed to fold upstream. While impeller 1710 is illustrated, the impeller 1712 can have the same or similar configuration, and the blades 1758 may be designed to fold downstream. In some embodiments, the impeller includes four blades per impeller. In some embodiments, the impeller includes two, three, four, five, six, seven, eight, nine, or ten blades or as described below. The blades can be made into an airfoil shape. In some embodiments, the impeller 1710 includes four blades, five blades, six blades, seven blades, eight blades, nine blades, ten blades, or any range of the foregoing values. In FIG. 181B, there are six blades in the circumference. There can be two impeller portions 1750, each impeller portion can include any number of blades. There can be two, three, four, five, six etc. blades per impeller portion 1750. The impeller portions 1750 can be stacked axially and rotated azimuthally. The portions 1750 can be stacked to form the impeller 1710. The impeller portions 1750 can be offset axially and rotated azimuthally with respect to each other. The blades of the impeller portions 1750 can alternate. The blades of the impeller portions 1750 can overlap. The impeller 1710 can provide for blade overlap at the hub circumference, and/or at the tip circumference, and/or at the tip circumference. The design can allow for smooth folding of the blades. The design can allow for easier folding compared with three dimensional blade shapes (in which the blade thickness varies from leading edge to trailing edge and from hub to tip). The design can allow for stacked impeller portions 1750. The design can allow for an overlap between blades at a hub, or any radial segment of the blades from hub to tip. The design with stacked and rotated impeller portions 1750 can allow for a large number of blades per impeller 1710. The larger number of blades per impeller 1710 can decrease the blade-to-blade flow gap, thus optimizing blade solidity and hydrodynamic performance. The larger number of blades per impeller 1710 can increase the solidity, i.e. more blades of the same shape in the circumference. The larger number of blades per impeller 1710 can provide better guidance to the flow. The larger number of blades per impeller 1710 can provide higher hydrodynamic efficiency. The impeller-portion 1750 can include three blades 1758 connected by the flat-plate circle 1779 at the center. The impeller 1710 can be composed of two identical impeller portions 1750 in which one is rotated azimuthally 60 degrees from the other, and connected together to each other and to impeller hubs 1778 to form a 6-bladed impeller assembly. The impeller 1710 can include blades 1758, with two cylindrical half shafts or hubs 1778 connecting them to flat-plate circle 1779 at the center. The impeller 1710, 1712 are impellers, with hubs, and blades. There can be an equal number of blades in the two impellers 1710, 1712. There can be different number of blades in the upstream and downstream impeller. The number of blades in each impeller can be a prime odd number. One impeller can have an even number of blades and one impeller can have odd number of blades. Both impellers can have even numbers of blades. The impellers can have 2, 3, 4, 6, 7, or 8 or more impeller portions or impeller segments 1750. The impellers can have 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 blades 1758 or any range of two foregoing values, such as from 2 blades to 19 blades 1758 per impeller 1710, 1712. In some embodiments, using different number of blades for the upstream and downstream impellers can minimize unsteady force. In some embodiments, using odd prime numbers of blades can facilitate rotor balancing.

[0596] The impeller portions 1750 can be manufactured from sheets of material. The shape of the three blade impeller portions 1750 can be cut out of sheets of shape-memory alloy, then heat treated to remain in a three-dimensional blade shape as shown in FIGS. 181B and 181C, where the blade angles at leading and trailing edge vary from hub to tip. A pair of these impeller segments 1750 can be placed together. The impeller portions 1750 can be rotated azimuthally, in this example 60 degrees. The impeller portions 1750 can be connected to two cylindrical half shafts or hubs 1778, one upstream and one downstream of the blades. These shafts can be considered the upstream hub and the downstream hub. The impeller portions 1750 and the hubs 1778 can be bonded or welded together to form the impeller 1710. The impeller portions 1750 and the hubs 1778 can be heat treated to achieve the three dimensional shape of the impeller 1710.

[0597] This can be done with a three-bladed impeller or with double blade constructs, as shown in FIGS. 181A-181C. This can be done with three, four, six, eight or more three-dimensional blades per impeller segment 1750. The upstream and downstream impeller geometries 1710 and 1712 do not need to have the same number of blades.

[0598] FIG. 182A-182F illustrates views of the impeller 1710, 1712. FIG. 182A illustrates a top view of the impeller 1710. The impeller 1710 can be formed by two stacked impeller segments 1750. The first blade is formed from the first impeller segment 1750 and the second adjacent set of blades is formed from the second impeller segment 1750. The impeller segments 1750 have stacked configuration, with an axial offset and a rotational offset. The blades of the impeller segments 1750 overlap.

[0599] FIG. 182B illustrates the scale of the impeller 1710. The impeller 1710 can have a small size. The impeller can have a diameter of 4 mm, 5 mm, 6 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, or any range between two of the foregoing values. In some embodiments, impellers with a diameter of 35 mm or greater can be used for the descending aorta. The blades can be airfoil plates shaped into three dimensional shapes. The inlet and outlet flow angles along the leading and trailing edge can vary from hub to tip. The corresponding blade angles can vary, accounting for incidence and deviation.

[0600] FIGS. 182C-182E illustrate the folding of the blades relative to the waist 1768 of the hourglass frame 1714. The catheter 1716 can be advanced toward the impeller 1712. The downstream impeller 1712 is illustrated. The impeller can fold upstream. The upstream impeller 1710 can fold in a similar manner as the downstream impeller 1712. The upstream impeller 1710 can fold in a different manner from the downstream impeller 1712. The impeller 1712 collapses by folding upstream. The advancing catheter 1716 collapses the waist 1768 of the hourglass frame 1714. The collapsing waist 1768 engages the overlapping blades of the downstream impeller 1712. The overlapping blades of the downstream impeller 1712 slide against each other. In this embodiment, while the blades are collected by the collapsing waist 1768 from the tip, the contact point folds the overlapping blades of the downstream impeller 1712 advancing from tip to hub. The line of contact points as the blade collapses may be different, depending on the geometric arrangement.

[0601] FIG. 182F illustrates the impellers 1710, 1712. The impellers 1710, 1712 can be contra-rotating, i.e. rotating in opposite directions. The upstream impeller 1710 can rotate in a first direction. The downstream impeller 1712 can rotate in a second direction, the second direction opposite the first direction. The impellers 1710, 1712 can have the same revolutions per minute (rpm). The impellers 1710, 1712 can have different revolutions per minute. The impellers 1710, 1712 can have the same number of blades. The impellers 1710, 1712 can have a different number of blades. The impellers 1710, 1712 can have the same shape. The impellers 1710, 1712 can have a different shape. The impellers 1710, 1712 can fold in the same direction. The impellers 1710, 1712 can fold in opposite directions. The hubs 1778 can include slots to accommodate assembly and disassembly, or they may be bonded or welded to the shafts. In some embodiments, the blades are bonded or welded to the hubs 1778 to form the impeller 1710, 1712.

[0602] This is a first application of these concepts in heart-assist pumps for temporary use. One way to minimize the unsteady force acting on the blades, thus maximizing the fatigue life of the pump head, is by careful selection of the number of blades. For instance, a 6-bladed upstream-impeller and 6-bladed downstream-impeller result in 6 large excitations on each blade and blade-hub connector of the downstream impeller per one revolution, or one excitation every 60 degrees of rotation. There is a variation in downstream-impeller blade load when the excitation (wake) from one upstream-impeller blade reaches a downstream blade. Choro-chronic (location and time) optimization of the propagation of unsteady forces is an important part of minimizing unsteady forces and maximizing fatigue life in modern turbomachines. Similarly, 8-bladed upstream-impeller and 8-bladed downstream-impeller result in 8 large excitations per revolution, one every 45 degrees of rotation. A 6-bladed upstream impeller and 8-bladed downstream-impeller change the relative time-location of wake interaction to potential-flow interaction, and thus reduce the number of large excitations per blade per revolution. Similarly, combinations of 6 with 7 bladed impellers, or 7 with 8 bladed impellers, or 7 with 9 bladed impellers, reduces large excitation per blade per revolution even more. Combinations of different odd and prime numbers of blades, 3 with 5, or 5 with 7, or 7 with 9 blades, in the contra-rotating impellers offer force-minimizing opportunities as well as rotor-balancing advantages. Selection of different number of blades between the two impellers has beneficial effects on the fatigue life of the blades. In some embodiments, there are different number of blades in the two impellers. In some embodiments, there are a different number of blades, e.g. 6 and 7, or 7 and 8, or 7 with 9 etc., to minimize unsteady force and maximize fatigue life. Odd numbers of blades facilitate rotor balancing, and prime odd numbers, e.g. 7 and 9 blades, facilitate rotor balancing as well as minimize unsteady forces.

[0603] The figures herein show how to construct 6 and 8 bladed impellers with two impeller portions 1750, and 7 bladed impellers with 3 impeller portions 1750. In some embodiments, the device 1700 uses one 7-bladed and one 9-bladed impeller. In some embodiments, the device 1700 uses the larger number of blades in the impeller that has higher hydrodynamic loading, and the smaller number of blades in the impeller with the lower hydrodynamic loading. While impeller 1710 is illustrated, the impeller 1712 can be constructed in a similar manner. The impellers 1710, 1712 can have same number of blades. The impellers 1710, 1712 can have a different number of blades. The impellers 1710, 1712 can have the same construction. The impellers 1710, 1712 can have different constructions.

[0604] FIG. 182G shows construction of a 6-bladed assembly with overlapping blades from two three-bladed impeller segments 1750, red and teal. This figure shows how to make a 6 bladed impeller. The first impeller segment has three blades. The second impeller segment has three blades. FIG. 182H shows construction of an 8-bladed assembly with overlapping blades from two four-bladed impeller segments 1750, red and teal. This figure shows how to make an 8 bladed impeller. The first impeller segment has four blades. The second impeller segment has four blades. FIG. 182i shows construction of a 7-bladed assembly with overlapping blades from one three-bladed impeller segment (red) and two two-bladed impeller segments (blue and teal). This figure shows how to make a 7 bladed impeller. The first impeller segment has three blades. The second impeller segment has two blades. The third impeller segment has two blades. Similarly, three three-bladed impeller segments can make a 9-bladed impeller, etc. In some embodiments, there are impellers with different numbers of blades. In some embodiments, there is an impeller with an even number of blades with an impeller with an even number of blades. In some embodiments, there is an impeller with an even number of blades with an impeller with an odd number of blades. In some embodiments, there is an impeller with an odd and prime number of blades with an impeller with an odd and prime number of blades. In some embodiments, there are impellers that have a balancing advantage and an unsteady force minimization.

[0605] The impeller 1710 can have any number of blades, including one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen or any range of two of the foregoing values. The impeller 1712 can have any number of blades, including one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen or any range of two of the foregoing values. The upstream impeller and the downstream impeller can have the same number of blades. The upstream impeller can have a greater number of blades than the downstream impeller. The downstream impeller can have a greater number of blades than the upstream impeller. The impeller 1710 can have any number of impeller segments 1750, including one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen or any range of two of the foregoing values. The impeller 1712 can have any number of impeller segments 1750, including one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen or any range of two of the foregoing values. The impeller segments 1750 can be stacked. The impeller segments 1750 can be adjacent. The impeller segments 1750 can be indexed, as described herein. The impeller can be constructed to have balancing advantages. The impeller can be constructed to have unsteady force minimization. The impeller can be constructed to have balancing advantages and unsteady force minimization.

[0606] FIGS. 182J and 182K illustrate impeller-segment indexing. There are many ways to assemble the multi-bladed impeller portions 1750 to the upstream and downstream hubs 1778. One of ways to assemble is to weld the impeller portions 1750 and hubs 1778 together. The welds alter the local crystalline structure of the material, thus altering the stress-strain characteristics of the nitinol material. This can result in unpredictable stress-strain behavior in the most sensitive part of the folding impellers, which is a hub-to-blade connector 1788, which connects the flat-plate circle 1779 to the blades 1758. In folding of the blades, the hub-to-blade connector 1788 is the region that is subjected to the maximum strain. In order to prevent permanent deformation of the hub-to-blade connector 1788 in folding and unfolding at three different temperatures, in some embodiments, the local welds are replaced. This is achieved with impeller-portion indexing or azimuthally positioning one impeller portion or segment in relation to the other with mechanical holds as shown in FIG. 182J. FIG. 182J, left to right, illustrates assembly of an 8-bladed impeller with an indexing arrangement holding the impeller segments 1750 mechanically in their set azimuthal positions. FIG. 182K also illustrates assembly of an 8-bladed impeller with an indexing arrangement holding impeller segments 1750 mechanically in their set azimuthal positions.

[0607] The first downstream hub tube 1778A shown in grey is cut with indexing poles. A second locating tube 1778B shown in blue of slightly larger diameter with surface cuts on its surface is inserted over the first hub tube 1778A. The first and second tube 1778A, 1778B are connected with biocompatible glue, or welded together at the locations of recesses in the second tube 1778B. The first impeller portion 1750A shown in green has corresponding indexing cuts 1791, shown also in FIG. 198, relative to the first tube 1778A and is inserted in the assembly, where it is stopped axially by the location of the larger tube 1778B shown in blue. The second impeller portion 1750B shown in pink also has indexing cuts 1791 at the hub, but at a different azimuthal positioning from the first impeller portion 1750A shown in green, and it is also inserted in the assembly. The location of the indexing cuts 1791 in the green and pink impeller segments 1750A, 1750B are chosen based on the desired azimuthal positioning of the first impeller portion 1750A shown in green in relation to the second impeller portion 1750B shown in pink. Then a third upstream hub tube 1778C shown in yellow, also cut with matching indexing poles to the first hub tube 1778A shown in gray, is inserted inside the first hub tube 1778A shown in gray. At this point the fourth tube 1778D shown in blue of slightly larger diameter than the third tube 1778C and with holes cut in its perimeter is inserted above the third tube 1778C shown in yellow, and attached to it with biocompatible glue or with welds at the holes of the fourth tube 1778D shown in blue. The upstream and downstream blue tubes 1778B and 1778D hold the impeller portions 1750A, 1750B in their axial position. The indexing tubes 1778A, 1778C hold the two impeller portions 1750A, 1750B in the desired azimuthal orientation, and also transmit torque from the hub to the blades of the impeller portions 1750A, 1750B. The overall assembly holds the impeller portions 1750A, 1750B in the desired axial and azimuthal orientation and transmit torque. The biocompatible glue or weld region is in a place away from the maximum strain region of the hub-to-blade connector 1788. In some embodiments, the indexing arrangement is configured to avoid welds. In some embodiments, the indexing arrangement is configured to carry torque.

[0608] Referring back to FIGS. 169G and 169H, in some embodiments, the core shaft 1720 extends to the nose cone 1724. A second hollow peripheral and partially perforated shaft called the tip extension 1722 is attached to the tip of the core shaft 1720. This second hollow shaft or tip extension 1722 extends back to connect with indexing poles 1778A and 1778C to the upstream impeller 1710. The impeller interconnect 1711 shown in FIG. 183F rotates freely between the two contra-rotating impellers 1710, 1712.

[0609] In some embodiments, the supporting structure 1780 or curvature controller is placed to limit the combination of bending and torsion stresses and strains. The last figure on the right shows the placement of the supporting structure of curvature controller 1780, discussed herein.

[0610] FIG. 183A-183D illustrate the impeller 1710. The impeller 1710 can include the upstream and downstream hubs 1778. The hubs 1778 can support the blades. The hubs 1778 can support the impeller segments 1750 containing the blades. The impeller 1710 can include one or more supporting structures 1780. The placement of supporting structure 1780 can be upstream of the airfoil. The placement of supporting structure 1780 can be downstream of the airfoil. In the illustrated embodiment, the supporting structures 1780 include an upstream and downstream supporting structures 1780. The supporting structures 1780 can be positioned relative to the impeller segments 1750 that support the blades. The supporting structures 1780 can be positioned relative the hubs 1778. The supporting structures 1780 can improve shaft rigidity between the shaft holders 1730, 1732. The supporting structures 1780 can eliminate or reduce the slow-flow regions near the hub 1778 and thus improve hydrodynamic performance. The supporting structures may have different cross sectional shapes than those in the figures.

[0611] FIGS. 183E-183G illustrate the impellers 1710, 1712. The impellers 1710, 1712 may be connected with a perforated impeller interconnect sleeve 1711. The core shaft 1720 in the centerline is already flexible. The slots on the impeller interconnect sleeve 1711 allow relative axial misalignment and bending of the shafts between the two impeller hubs during implantation and also during operation. The hole on the impeller interconnect sleeve 1711 allows flushing/lubricant between the two impellers 1710, 1712. The lubricant is in the space between the core shaft 1710 and the impeller hubs as described herein. The impeller interconnect sleeve 1711 can be external to impeller hubs. The impeller interconnect sleeve 1711 can be internal to impeller hubs. The impellers on either side of impeller interconnect sleeve 1711 rotate in opposite directions. The interconnect sleeve 1711 acts as a bearing between contra-rotating impellers 1710, 1712.

[0612] FIGS. 184A-184D illustrate the contra-rotating flexible shafts. FIG. 184A illustrates the core shaft 1720, the peripheral shaft 1726, and the shaft sheath 1704. FIG. 184B illustrates an exploded view of the core shaft 1720, the peripheral shaft 1726, and the shaft sheath 1704. FIG. 184C illustrates a cross-sectional view of the core shaft 1720, the peripheral shaft 1726, the shaft sheath 1704, and the catheter 1716. The core shaft 1720, the peripheral shaft 1726, the shaft sheath 1704, and the catheter 1716 can be concentric. The core shaft 1720, the peripheral shaft 1726, the shaft sheath 1704, and the catheter 1716 can be coaxial. FIG. 184D illustrates a cross-sectional view of the core shaft 1720, the peripheral shaft 1726, and the shaft sheath 1704. The core shaft 1720 can be disposed within the peripheral shaft 1726. There can be a fluid pathway between the core shaft 1720 and the peripheral shaft 1726. The peripheral shaft 1726 can be disposed within the shaft sheath 1704. There can be a fluid pathway between the peripheral shaft 1726 and the shaft sheath 1704. The shaft sheath 1704 can be disposed within the catheter 1716. There can be a fluid pathway between the shaft sheath 1704 and the catheter 1716. The core shaft 1720 extends to upstream impeller, also to the tip extended, welded at the tip to external perforated tube called tip extender, that extends back to upstream impeller upstream indexing device.

[0613] The core shaft 1720 can be flexible. The core shaft 1720 can rotate in a first direction. The core shaft 1720 can rotate in one direction around its axis. The core shaft 1720 can be inserted inside the peripheral shaft 1726. The core shaft 1720 can extend beyond the peripheral shaft 1726. The core shaft 1720 can extend from the proximal motor 1706 to the upstream impeller 1710. The core shaft 1720 can extend the majority of the length of the device 1700.

[0614] The peripheral shaft 1726 can be flexible. The peripheral shaft 1726 can be hollow. The peripheral shaft 1726 can rotate in a second direction. The peripheral shaft 1726 can rotate in the opposite direction around its axis at equal or unequal rpm to the core shaft. The peripheral shaft 1726 can be placed around the core shaft 1720. The core shaft 1720 can be coaxial with the peripheral shaft 1726. The peripheral shaft 1726 can extend from the distal motor 1708 to the downstream impeller 1712. The peripheral shaft 1726 can extend the majority of the length of the device 1700. The core shaft 1720 and the peripheral shaft 1726 can be configured to rotate. The peripheral shaft 1726 can be coiled wire, or double coiled wire with coils rotating in same or in opposite directions as in FIG. 185C, or perforated shaft as in FIG. 185F. Any lubricious coating such as PTFE can be used on the shafts. The peripheral shaft 1726 can be perforated. The core shaft 1720 can be a solid or wire strand. The core shaft 1720 can have a lubricious coating like PTFE on an outer perimeter of the core shaft 1720. The peripheral shaft 1726 can have a lubricious coating like PTFE coating on inside or outside of the peripheral shaft 1726. The peripheral shaft 1726 can have no coating on the peripheral shaft. Around the peripheral shaft 1726 is a stationary shaft sheath 1704. This shaft sheath 1704 may be made of PTFE. If the core shaft 1720 is PTFE coated and the shaft sheath 1704 is PTFE, then the peripheral shaft 1726 may not need a lubricious coating.

[0615] The perforations in the peripheral shaft 1726 may allow flush/lubricant to flush/lubricate whatever is outside the peripheral shaft. For instance, at tip extender perforations on the peripheral tube 1722 allows flush lubrication to enter the space between the rotating peripheral perforated tube of the tip extender 1722 and the stationary inner diameter of the nose cone 1724, which then exits into the blood stream at the shaft holder 1730.

[0616] There can be PTFE or any biocompatible lubricious coating. The peripheral shaft 1726 can be perforated. The core shaft 1720 can be a solid or wire strand. There may have lubricious coating like PTFE on an outer perimeter of core shaft 1720. There may be PTFE coating on inside or outside of the peripheral shaft 1726, or no coating on the peripheral shaft 1726. Around the peripheral shaft 1726 is a stationary shaft sheath 1704. This shaft sheath 1704 may be made of PTFE. If the core shaft 1720 is PTFE coated and the shaft sheath 1704 is PTFE, the peripheral shaft 1726 may not be PTFE coated.

[0617] The shaft sheath 1704 can be flexible. The shaft sheath 1704 can be a sleeve. The shaft sheath 1704 can be stationary. The shaft sheath 1704 can be placed around the peripheral shaft 1726. The shaft sheath 1704 can be surround both the peripheral shaft 1726 and the core shaft 1720. The peripheral shaft 1726 and the core shaft 1720 can be coaxial with the shaft sheath 1704. The core shaft 1720 can be solid. The core shaft 1720 can be a braided wire. The core shaft 1720 can be hollow. The core shaft 1720 can be another similar structure. The peripheral shaft 1726 and the shaft sheath 1704 can be hollow. The shaft sheath 1704 can extend the length of the peripheral shaft 1726. The shaft sheath 1704 can extend the majority of the length of the device 1700. The shaft sheath 1704 may be made of PTFE.

[0618] The core shaft 1720 can be made of biocompatible plastic or metal or memory alloy, such as Nitinol. The core shaft 1720 can include a coating. The coating may be biocompatible. The core shaft 1720 can include a biocompatible coating like PTFE. The coating can be disposed on the outer surface of the core shaft 1720. The coating can be along the entire length of the core shaft 1720 or a portion thereof. The peripheral shaft 1726 can be made of biocompatible plastic or metal or memory alloy, such as Nitinol. The peripheral shaft may have coating on its exterior surface, on its interior surface, or both surfaces, and this coating may be biocompatible. The core shaft 1720 and the peripheral shaft 1726 can be made of the same material. The core shaft 1720 and the peripheral shaft 1726 can be made of different materials. The coating of surfaces described can reduce friction between rotating shafts, and between the peripheral shaft 1726 and the shaft sheath 1704. The coating can be used alone or in combination with flushing and lubrication.

[0619] The peripheral shaft 1726 can include a coating. The peripheral shaft 1726 can include a biocompatible coating like PTFE. The coating can be disposed on the outer surface of the peripheral shaft 1726, toward the shaft sheath 1704. The coating can be disposed on an inner surface of the peripheral shaft 1726, toward the core shaft 1720. The coating can be disposed on the outer surface and the inner surface of the peripheral shaft 1726. The coating can be along the entire length of the peripheral shaft 1726 or a portion thereof.

[0620] The shaft sheath 1704 can include a coating. The shaft sheath 1704 can include a biocompatible coating like PTFE. The coating can be disposed on the outer surface of the shaft sheath 1704, toward the catheter 1716. The coating can be disposed on an inner surface of the shaft sheath 1704, toward the peripheral shaft 1726. The coating can be disposed on the outer surface and the inner surface of the shaft sheath 1704. The coating can be along the entire length of the shaft sheath 1704 or a portion thereof.

[0621] The catheter 1716 can include a coating. The shaft sheath 1704 can include a biocompatible coating like PTFE. The coating can be disposed on an inner surface of the catheter 1716, toward the shaft sheath 1704. The coating can be along the entire length of the catheter 1716 or a portion thereof.

[0622] The device 1700 can include a shaft seal 1784. The shaft seal 1784 can be disposed between the shaft sheath 1704 and the catheter 1716. The shaft seal 1784 can be flexible. The shaft seal 1784 can be stationary. The shaft seal 1784 can be made of biocompatible metal or alloy, or PTFE, or may be a fluid bladder. The device 1700 installed in the vasculature in a collapsed state via a catheter 1716. Then, the device 1700 can be expanded for operation. After a period of use, the device 1700 can be collapsed in the catheter 1716 as described herein. The shaft seal 1784 can prevent fluid flow from the catheter 1716 during use.

[0623] The core shaft 1720 and the peripheral shaft 1726 can contra-rotate. The peripheral shaft 1726 can rotate relative to the stationary shaft sheath 1704. Friction between the contra-rotating shafts 1720, 1726, and between the peripheral shaft 1726 and shaft sheath 1704 can occur. In some embodiments, the friction can be managed by the biocompatible coatings between the surfaces (e.g. PTFE coatings). In some embodiments, the friction can be managed by lubrication paths. There can be one, two, or three lubrication paths. The first lubrication path can be between the core shaft 1720 and peripheral shaft 1726. The second lubrication path can be between the peripheral shaft 1726 and the shaft sheath 1704. The third lubrication path can be between the shaft sheath 1704 and the catheter 1716. The lubrication path can be a flushing passage. The lubrication paths can also be called also flush paths. There can be four or more lubrication or flush paths. The fourth lubrication and flush path can be between the catheter 1716 and the catheter introducer 1718.

[0624] FIG. 185A-185G illustrate embodiments of the various shafts. FIG. 185A illustrates a solid Nitinol wire as the core shaft 1720. The nose cone 1724 can be connected to the core shaft 1720. The nose cone 1724 can be integrally formed with the core shaft 1720. The core shaft can be 0.5 mm, 0.75 mm, 1 mm, 1.25 mm, 1.5 mm, 1.75 mm, 2 mm, or any range of the foregoing values. FIG. 185B illustrates a braided cable as the core shaft 1720. FIG. 185B illustrates a nitinol tube with twisted wires which can form the core shaft 1720, the peripheral shaft 1726, the shaft sheath 1704, or the catheter 1716. FIG. 185D illustrates hyptotubes which can form the core shaft 1720, the peripheral shaft 1726, the shaft sheath 1704, or the catheter 1716. FIG. 185E illustrates the peripheral shaft 1726 and the core shaft 1720. FIG. 185F illustrates another form of a hypotube which can form the core shaft 1720, the peripheral shaft 1726, the shaft sheath 1704, or the catheter 1716. The peripheral shaft may be perforated, or have slots, in various paces along its length, to accommodate folding, and also flow of flushing/lubricant in its radial direction. FIG. 185G shows the core and perforated peripheral shaft 1726.

[0625] FIG. 185C-185F show twisted wires and perforated tube 1720 and 1726. In some embodiments, the shaft sheath 1704 and the catheter 1716 are unlikely to be coils, and are likely PTFE. The core shaft 1720 can go down to 0.2 mm. The core shaft 1720 can be between 0.30 and 0.65 mm.

[0626] The core shaft 1720 can be made of a solid cylindrical plastic or memory-shape alloy, like Nitnol. The core shaft 1720 can be made a wire strand. The core shaft 1720 can be covered with a biocompatible coating, like PTFE. The peripheral shaft 1726 can be made of a cylindrical tube. The peripheral shaft 1726 can be made of a solid or perforated tube. The peripheral shaft 1726 can include a helical slot. The peripheral shaft 1726 can include spiral, or may be two coils rotating in opposite directions. The peripheral shaft 1726 can include any perforated shape. The peripheral shaft 1726 can include circumferential slots. The peripheral shaft 1726 can include longitudinal slots. The peripheral shaft 1726 can be made of twisted-wire tubes. The peripheral shaft 1726 can made of plastic or memory-shape alloy, like nitnol. The interior or exterior or both surfaces of the peripheral shaft 1726 can be covered with a biocompatible coating, like PTFE. In some embodiments, the coatings of the core shaft 1720, the peripheral shaft 1726, and the shaft sheath 1704 can be sufficient to run the device unlubricated. In some embodiments, the coatings may be used to control the quantity and flow rate of lubricant paths described herein.

[0627] FIG. 186A-186C illustrate the shaft arrangement. The device can include the shaft sheath 1704. The shaft sheath 1704 can be non-rotating. The shaft sheath 1704 can be attached to shaft holder 1734. The shaft holder 1734 can be non-rotating. The shaft holder 1734 can be a fixed distance from the upstream tip of motor 1708. The core shaft 1720 can go through the peripheral shaft 1726. The core shaft 1720 can be attached to the upstream impeller 1710. The core shaft 1720 can be connected to the tip extension 1722. There can be a tip extension 1722 welded at the tip of the core shaft 1720. The tip extension 1722 can become the pivot point for collapsing. The core shaft 1720 can be flexible. The peripheral shaft 1726 can be partially flexible and partially rigid. The peripheral shaft 1726 can be attached to the downstream impeller 1712. The shaft holders 1730, 1732, 1734 can slide relative to the peripheral shaft 1726. The shaft holders 1730, 1732, 1734 can slide relative to the tip extension 1722. One shaft holder 1730, 1732, 1734 can be fixed. In the embodiment described here, the shaft holder 1734 is not sliding in relation to the shafts, and is attached to, bonded, welded, or the same part as the tip of shaft sheath 1704. Referring to FIGS. 172-175, one of the shaft holders 1730, 1732, 1734 needs to be at fixed axial in relation to the motors as the device collapses, and the other two shaft holders slide. In FIGS. 172, 174 and 175, the shaft holder 1734 is fixed. In FIG. 173, the shaft holder 1730 is fixed. In the some embodiments, the shaft holders 1730 and 1732 slide up the shafts for collapsing and the shaft holder 1734 is fixed at a set axial distance from the motors and tip extender 1722 becomes the pivot for collapsing.

[0628] The peripheral shaft 1726 can connect to the hub 1778 of the impeller 1712. The peripheral shaft 1726 can rotate causing the impeller 1712 to rotate. The peripheral shaft 1726 can be driven by the motor 1708. The core shaft 1720 can connect to the hub 1778 of the impeller 1710. The core shaft 1720 can rotate causing the impeller 1710 to rotate. The core shaft 1720 can be driven by the motor 1706. The core shaft 1720 and the peripheral shaft 1726 can rotate simultaneously. The core shaft 1720 and the peripheral shaft 1726 can rotate independently.

[0629] In some embodiments, the device 1700 can run unlubricated, using the biocompatible shaft coatings described herein. The fluid dynamic advantages allow the pump to achieve maximum performance at low speed. In some embodiments, there may be flushing and/or lubrication between the following components. There may be flushing and/or lubrication between the core shaft 1720 and the peripheral shaft 1726. These shafts 1720, 1726 are contra-rotating. There is twice the pump revolutions per minute between the core shaft 1720 and the peripheral shaft 1726 because the shafts are rotating in opposite directions. There may be flushing and/or lubrication between the peripheral shaft 1726 and the shaft sheath 1704. The shaft sheath 1704 is not rotating. There is one time the pump revolutions per minute between peripheral shaft 1726 and the shaft sheath 1704. There may be flushing and/or lubrication between the shaft sheath 1704 and the catheter or catheter 1716. The shaft sheath 1704 is not rotating. The catheter 1716 is not rotating. These pathways can be for flushing and/or lubrication. Thus, there is provision for up to three pathways for flushing/lubrication. There can be a fourth lubrication or flush pathway between the catheter 1716 and the catheter introducer 1718.

[0630] FIG. 186B illustrates the tip extension 1722. The tip extension 1722 can be flexible. The tip extension 1722 can include one or more features such as grooves to increase flexibility. The tip extension 1722 can be rigid near the shaft holder 1730. The tip extension 1722 near the shaft holders 1730 can omit the slots that facilitate flexibility. The tip extension 1722 can couple to the core shaft 1720 (bonding, weld etc.).

[0631] FIG. 186C illustrates the peripheral shaft 1726 near the shaft holder 1734. The portion of the shafts 1720, 1726 between shaft holders 1730, 1732 can be rigid. In some embodiments, the peripheral shaft 1726 between shaft holders 1730, 1732 is more rigid than another portion of the peripheral shaft 1726. The peripheral shaft 1726 between shaft holders 1732, 1734 can be more flexible than the peripheral shaft 1726 between shaft holders 1730, 1732. The peripheral shaft 1726 between shaft holders 1732, 1734 can include one or features such as grooves to increase flexibility. The peripheral shaft 1726 between shaft holders 1730, 1732 can be made more rigid. The peripheral shaft 1726 between shaft holders 1730, 1732 can be reinforced. The peripheral shaft 1726 between shaft holders 1730, 1732 can omit the slots that facilitate flexibility. The peripheral shaft 1726 can include features such as grooves or holes to allow flush/lubricant to reach outside the peripheral shaft 1726 at various component locations, such as near the shaft holders 1730, 1732, 1734 and the indexing mechanisms.

[0632] FIG. 187A-187B illustrate the flushing/lubrication pathways. There can be up to three fluid pathways. The core shaft 1720 can be a thin center shaft, pictured extending from the motor 1706 (not shown). The core shaft 1720 extends all the way to the nose cone 1724. The motor 1708 is shown. To the right of the motor 1708 is a system with two sealed shaft holders 1744, the plug 1746, and the Luer connection 1736. The Luer connection 1736 connects to the first pathway for flushing/lubrication. The first pathway is between the core shaft 1720 and the peripheral shaft 1726. Immediately upstream of 1708 is the rotating coupling for the shaft of motor 1708 to the peripheral shaft 1726. Seals like o-rings in the coupling ensure the flushing/lubrication liquid is supplied along the pathway, between the core shaft 1720 and the peripheral shaft 1726. In some embodiments, there are four fluid paths. In some embodiments, there are quick disconnects motors. In some embodiments, there are venting and sterilizing to re-use the motor.

[0633] Immediately downstream of the coupling is a stationary support structure with the Luer connection 1738. The Luer connection 1738 connects to the second pathway for flushing/lubrication. The second pathway is between the peripheral shaft 1726 and the shaft sheath 1704. A sealed shaft holder and seals like o-rings inside the supporting structure ensure that the flushing liquid is supplied along the pathway, between the peripheral shaft 1726 and the shaft sheath 1704. The seals like o-rings at the left side of the support structure secure in place the shaft sheath 1704.

[0634] The catheter 1716 has two Luer connections 1740, 1742. The Luer connection 1740 is for the flushing/lubrication liquid, between the shaft sheath 1704 and the catheter 1716. The Luer connection 1742 is for the fluid such as air, gas or liquid to seal the space between the shaft sheath 1704 and catheter 1716. The Luer connection 1742 can be used for the shaft seal 1784. The shaft seal 1784 can be an inflatable sealing arrangement. The Luer connection 1742 can be used to inflate a bladder of the shaft seal 1784 at the downstream end of the catheter, between the catheter 1716 and the shaft sheath 1704. Alternatively, instead of the inflatable bladder, this may be a seal such as an O-ring or similar sealing structure.

[0635] The three flushing liquid paths connected to the Luer connections 1736, 1738, 1740 can be separate pathways, as shown. In some embodiments, one pressure and/or gravity feed bag can be provided that provides flushing fluid to the three Luer connections 1736, 1738, 1740. Fluid can be provided simultaneously. Fluid can be provided separately or sequentially. Fluid can be provided alternatively. Fluid can be provided to allow leakage from the first pathway to the second pathway to the third pathways using just one Luer connection.

[0636] FIG. 188 illustrates the fluid pathways. Two or more of the flushing fluid pathways may be combined into one. Two or more of the fluid pathways can be combined by slits or openings 1748 between the peripheral shaft 1726 and the core shaft 1720, the peripheral shaft 1726 and the shaft sheath 1704, and/or the shaft sheath 1704 and the catheter 1716. For example, the peripheral shaft 1726 can include one or more slots or opening that allow fluid to flow between the first pathway between the core shaft 1720 and the peripheral shaft 1726, and the second pathway between the hollow peripheral shaft 1726 and the shaft sheath 1704. For example, the shaft sheath 1704 can include one or more slits or opening 1748 that allow fluid to flow between the second pathway between the peripheral shaft 1726 and the shaft sheath 1704 and the third pathway between the shaft sheath 1704 and the catheter 1716. For example, the peripheral shaft 1726 can include one or more slits or opening 1748 that allow fluid to flow between first pathway between the core shaft 1720 and the peripheral shaft 1726 and the second pathway between the peripheral shaft 1726 and the shaft sheath 1704.

[0637] FIGS. 189A-189B illustrate features of the device 1700. One or more shafts can include a spiral insert 1786. The spiral 1786 can be biocompatible. The spiral 1786 can be a spiral coating around the shafts. The cross section of 1786 may be circular, rectangular etc. The spiral 1786 can be disposed on the core shaft 1720. The spiral 1786 can be disposed on the peripheral shaft 1726. The spiral 1786 can be formed from PTFE. The spiral 1786 can be radially constrained. The spiral 1786 can help pump flushing or lubricant fluid along the length of the shafts. The spiral 1786 can be used to assist pumping of the flushing fluid by acting as an axial helical pump. The spiral 1786 can be formed on the corresponding shaft 1720, 1726. The spiral 1786 can rotate as the shaft rotates. The spiral 1786 can act as an auger to flush fluid. The spiral 1786 can be radially constrained within the corresponding sheath.

[0638] FIG. 190 illustrates the rig used to test the hydraulic performance of the pump. The hourglass frame 1714 can be installed in an o-loop, with only a portion of the o-loop shown. The catheter 1716 is shown in the figure. The catheter introducer can extend from the o-loop and is not used in bench tests. The outer diameter of the pump head can be identical to the shape to be installed in the vasculature. The device 1700 had advantageous tested pump performance.

[0639] FIG. 191 is a graph of pump performance of the device 1700. As described herein, there can be a controlled gap between the expanded waist 1768 and the impellers 1710, 1712. For this graph, there was a 0.5 mm gap between impeller tip and waist inner diameter. This device was testes for different motor rpm, including 2000 rpm, 3000 rpm, 4000 rpm, 5000 rpm, and 6000 rpm. The configurations provided a change in pressure (mm Hg) per output in (L/min). As one example, this configuration of device 1700 provides 5 L/min and 30 mm Hg at 5,400 rpm. Even higher pressure rise can be achieved at higher rpm.

[0640] FIG. 192 is a graph of pump performance. There was a 1.0 mm gap between impeller tip and the inner diameter of the expanded waist 1768. This configuration provides 5 lt/min and 30 mm Hg at 6,100 rpm. Even higher pressure rise can be achieved at higher rpm. The device 1700 can be used at various rpms. The device 1700 can be implanted and used for various lengths of time. The device 1700 can deliver 30 mmHg and 5 lt/min at 6,000 rpm. The device can be used and then successfully explanted. The device 1700 can be inserted via a guide wire. The device 1700 can be introduced through a separate catheter introducer 1718 in addition to the catheter 1716. The whole device 1700 can be inserted through the catheter introducer 1718. The catheter can be 8-22 Fr. The catheter introducer 1718 can be 10-26 Fr. The catheter 1716 may be inserted via a catheter introducer 1718. The catheter 1716 and the catheter introducer 1718 can be two separate components. The shaft holders 1730, 1732, 1734 can be modified to accommodate lubrication. The catheter 1716 can be about 12 French (4 mm diameter) and the catheter introducer 1718 can be marginally larger. In some embodiments, the device can be collapsed and expanded repeatedly in 12 French (4 mm diameter) catheter with blades and frame not going in plastic deformation and not breaking.

[0641] The device 1700 can include folding contra-rotating blades 1710, 1712 inside the folding hourglass shape 1714 with the inlet 1766, the waist 1768, and the diffuser 1770 installed in the descending or ascending aorta.

[0642] The contra-rotating impellers 1710, 1712 can be driven via one or more intra-corporeal or extra-corporeal motors. The contra-rotating blades 1710, 1712 can be driven via gearbox arrangements. In some embodiments, one extra-corporeal motor was driving one extra-corporeal single-input two-output contra-rotating-shaft gearbox. Each impeller segment 1750 can be made starting from cutting a two-dimensional nitinol sheet into the two-dimensional shape of the impeller segment 1750, then heat treating the shape into a three-dimensional blade row. The impeller segments 1750 can stacked to form the impellers 1710, 1712. From the gearbox, coaxial contra-rotating shafts can deliver power to the intra-corporeal folding contra-rotating blades 1710, 1712 in the collapsible hourglass. The contra-rotating blades 1710, 1712 can be driven a different arrangement. The contra-rotating blades 1710, 1712 can be driven with two co-axial contra rotating motors 1706, 1708 in series. The motors 1706 and 1708 may be extra corporeal, intra corporeal, or one extra corporeal and one intra corporeal. This arrangement can advantageously eliminate the complexity of the gearbox, and associated gearbox friction. The blades can also be made into three-dimensional shapes with techniques shown in FIG. 154C.

[0643] The contra-rotating blades 1710, 1712 can include better geometry. Each impeller can include a pair of impeller segments 1750. Each impeller segment 1750 can include three or more blades. Each impeller segment 1750 can be a three dimensional plate. The impeller segments 1750 can stack to form the impeller 1710, 1712. The impeller segments 1750 can be offset. The impeller segments 1750 can overlap. The blades of the impeller 1710, 1712 can be designed to fold upstream. The blades of the impeller 1710, 1712 can be designed to fold downstream. The impellers 1710, 1712 can include one or more supporting structures 1780 near the hub of the blades. The supporting structures 1780 can improve shaft rigidity near the blades 1710, 1712. The supporting structures 1780 can eliminate or reduce the slow-flow regions near the blades 1710, 1712. The supporting structures 1780 can improve hydrodynamic performance. The contra-rotating blades 1710, 1712 can be the result of improved manufacturing process for the folding blades. Each impeller can include any range of number of blades. Each impeller can have three-dimensional shaped blades. The number and shape of blades can facilitate smooth folding.

[0644] The hourglass frame 1714 can include improved geometry. The hourglass frame 1714 can be configured to fold. The hourglass frame 1714 can include the inlet 1766. The hourglass frame 1714 can include the waist 1768. The hourglass frame 1714 can include the diffuser 1770. The hourglass frame 1714 can include two or more segments joined together. The hourglass frame 1714 can be configured to axially lengthen and radially collapse. The hourglass frame 1714 can include the shaft holders 1730, 17320, 1734.

[0645] The hourglass frame 1714 can include the supporting struts 1760, 1762, 1764. The supporting struts 1760, 1762, 1764 can be folded inside the hourglass frame 1714. The supporting struts 1760, 1762 can include a transition between the waist 1768 and the shaft holders 1730, 1732. The supporting struts 1760, 1762, the waist 1768, and the shaft holders 1730, 1732 can be integrally formed. The supporting struts 1764 can include a transition between the diffuser 1770 and the shaft holders 1734. The supporting struts 1764, the diffuser 1770, and the shaft holder 1734 can be integrally formed. The hourglass frame 1714 can include the struts 1790, 1792, 1794. The struts 1790, 1792, 1794 can connect to the shaft holders 1730, 1732, 1734. The struts 1790, 1792, 1794 and the shaft holders 1730, 1732, 1734 can be integrally formed. The struts 1790, 1792, 1794 can facilitate the collapse of the hourglass frame 1714. One or more struts 1790, 1792, 1794 can fold upstream. One or more struts 1790, 1792, 1794 can fold downstream. The strut 1790 can connect to the upstream end, a midpoint, or a downstream end of the inlet 1766 and the shaft holder 1730. The strut 1792 can connect to the upstream end or a midpoint of the diffuser 1770 and the shaft holder 1732. The strut 1794 can connect to the downstream end of the diffuser 1770 and the shaft holder 1734.

[0646] The device 1700 can include contra-rotating shafts 1720, 1726. The core shaft 1720 and the peripheral shaft 1726 can rotate in opposite directions. The peripheral shaft 1726 can cover the core shaft 1720 or a portion thereof. The device 1700 can include a shaft sheath 1704. The shaft sheath 1704 can surround the contra-rotating shafts 1720, 1726, or a portion thereof. The shaft sheath 1704 can be nonrotating. The shaft sheath 1704 can cover the shafts 1720, 1726 along at least a portion of the length. The device 1700 can include the catheter or catheter 1716. The catheter 1716 can axially move to expand or contract over the hourglass frame 1714 and the blades 1710, 1712 contained therein. The catheter 1716 can cover the shaft sheath 1704, or a portion thereof.

[0647] The device 1700 can include lubrication paths and flushing arrangements of the shafts with biocompatible fluid. The device 1700 can include a lubrication path between the core shaft 1720 and the peripheral shaft 1726. The device 1700 can include a lubrication path between the peripheral shaft 1726 and the shaft sheath 1704. The device 1700 can include a lubrication or flushing path between the shaft sheath 1704 and the catheter 1716. The device 1700 can include an additional fluid path for inflating the shaft seal 1784. The shaft seal 1784 can be disposed between the catheter 1716 and the shaft sheath 1704.

[0648] The device 1700 can have folding and unfolding geometries. In some embodiments, the blades of impellers 1710, 1712 fold upstream. In some embodiments, the blades of impellers 1710, 1712 fold downstream. In some embodiments, the blades of impellers 1710, 1712 fold in the same direction. In some embodiments, the blades of impellers 1710, 1712 fold in opposite directions. The struts 1790, 1792, 1794 can facilitate the direction of folding. The shaft holders 1730, 1732, 1734 can be fixed or slidable. In some embodiments, the upstream shaft holder 1730 is fixed and the other shaft holders 1732, 1734 slide. In some embodiments, the downstream shaft holder 1734 is fixed and the other shaft holder 1730, 1732 slide. The fixed shaft holder can facilitate the direction of folding.

[0649] The device 1700 can be recoverable. The device 1700 can be temporarily installed within the vasculature of the patient. The device 1700 can be recovered using the supporting struts 1764 and/or the struts 1794. The supporting struts 1764 can connect the diffuser 1770 to the shaft holder 1734. The struts 1794 can connect the diffuser 1770 to the shaft holder 1734. The shaft holder 1734 can be collapsed downward, thereby collapsing the supporting struts 1764, the struts 1794, and the diffuser 1770. By pulling on the diffuser 1770 to axially lengthen the diffuser 1770, the rest of the hourglass frame 1714 can axially lengthen and radially constrict. The waist 1768 of the hourglass frame 1714 can axially lengthen and radially constrict, thereby facilitating the folding of the hourglass frame and the blades of impellers 1710, 1712.

[0650] The device 1700 can include the diffuser 1770. The diffuser 1770 can be shaped to facilitate distal outflow. The diffuser 1770 can include a mesh or lattice structure. The space between any of the supporting struts 1764 of the diffuser 1770 can have as dense a mesh or lattice as the space on the perimeter of the hourglass frame 1714. The supporting struts 1764 can include a dense mesh or lattice therebetween.

[0651] The device 1700 can include a nose cone 1724. The nose cone 1724 can facilitate smooth entry in the aorta. The nose cone 1724 can guide the flow into the upstream impeller 1710. The nose cone 1724 can be coupled to the core shaft 1720.

[0652] The device 1700 can include the catheter 1716. The catheter 1716 can be a sheath loading catheter. The catheter 1716 can be a delivery catheter. The catheter 1716 can allow collapse, accurate placement, and recovery of the pump head. The pump head can include the contra-rotating impellers 1710, 1712 inside the hourglass frame 1714.

[0653] The device 1700 can include contra-rotating shafts 1720, 1726. The contra-rotating shafts 1720, 1726 can include the core shaft 1720 disposed within the peripheral shaft 1726. The contra-rotating shafts 1720, 1726 can be flexible. The peripheral shaft 1726 can include one or more sections of increased flexibility. The peripheral shaft 1726 can include one or more sections of increased rigidity. The contra-rotating shafts 1720, 1726 rotate in opposite directions. The contra-rotating shafts 1720, 1726 can be driven by separate motors 1706, 1708. The contra-rotating shafts 1720, 1726 can be coaxial. The core shaft 1720 can rotate the upstream impeller 1710. The peripheral shaft 1726 can rotate the downstream impeller 1712. The impellers 1710, 1712 can rotate in opposite directions.

[0654] The device 1700 can include a biocompatible covering of the hourglass frame 1714. The covering of material 1774 can be interior to the hourglass frame 1714. The covering of material 1774 can be exterior to the hourglass frame 1714. The covering of material 1774 can be on both sides of the hourglass frame 1714. The covering of material 1774 can be on the inlet 1766, along the entire length or a portion thereof. The covering of material 1774 can be located at the waist 1768, along the entire length or a portion thereof. The covering of material 1774 can be on the diffuser 1770, along the entire length or a portion thereof. The covering of material 1774 can be omitted from the inlet 1766. The covering of material 1774 can be omitted from the waist 1768. The covering of material 1774 can be omitted from the diffuser 1770. The material 1774 can include one or more openings 1776. The material 1774 can include one or more openings 1776 at any one of, or all of, the inlet 1766, the waist 1768, and the diffuser segments 1770.

[0655] In some embodiments, a mechanical circulatory support heart-assist device is provided. The device can be configured to be inserted with minimally invasive surgery. The device 1700 can include a pump head. The pump head can include at least two contra-rotating impellers 1710, 1712. The contra-rotating impellers 1710, 1712 can be non-magnetic. The contra-rotating impellers 1710, 1712 can be considered shrouded impellers because they rotate inside waist segment 1768 which is covered with biocompatible material 1774. The contra-rotating impellers 1710, 1712 can be unshrouded impellers by omitting the biocompatible covering 1774. In some embodiments, the hourglass-shaped frame 1714 is included in the pump head. In some embodiments, the hourglass-shaped frame 1714 is omitted from the pump head. The contra-rotating impellers 1710, 1712 can be installed in the vasculature. The contra-rotating impellers 1710, 1712 can rotate at equal revolutions per minute. The contra-rotating impellers 1710, 1712 can rotate unequal revolutions per minute.

[0656] The contra-rotating impellers 1710, 1712 can be driven by one or more motors. The contra-rotating impellers 1710, 1712 can be driven by two motors 1706, 1708. The contra-rotating impellers 1710, 1712 can be driven coaxial motors 1706, 1708. The contra-rotating impellers 1710, 1712 can be driven by contra-rotating motors 1706, 1708. The contra-rotating impellers 1710, 1712 can be driven by two coaxial contra-rotating motors 1706, 1708. The motors 1706, 1708 can be intra-corporeal. The motors 1706, 1708 can be extra-corporeal. One motor can be extra corporeal and one motor can be intra corporeal as shown in FIG. 164B.

[0657] In some embodiments, the blades of contra-rotating rotors 1710, 1712 can be foldable. The contra-rotating rotors 1710, 1712 can be foldable against hubs 1778. The contra-rotating rotors 1710, 1712 can be foldable for device installation. The contra-rotating rotors 1710, 1712 can be foldable for device removal. The contra-rotating rotors 1710, 1712 can be foldable during placement within a blood vessel.

[0658] In some embodiments, the contra-rotating rotors 1710, 1712 can have a minimum diameter about 4 mm, including the unfolded blades. In some embodiments, the contra-rotating rotors 1710, 1712 can have a maximum diameter with unfolded blades 35 mm. In some embodiments, the contra-rotating rotors 1710, 1712 can have a maximum diameter with unfolded blades 60 mm. In some embodiments, the contra-rotating rotors 1710, 1712 can have a diameter of 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, 50 mm, 51 mm, 52 mm, 53 mm, 54 mm, 55 mm, 56 mm, 57 mm, 58 mm, 59 mm, 60 mm, or any range of two of the foregoing values.

[0659] The device 1700 can include the hourglass frame 1714. In some embodiments, the contra-rotating folding rotors 1710, 1712 are inside a folding hourglass-shaped frame 1714. The hourglass-shaped frame 1714 can have an expanded shape. The hourglass-shaped frame 1714 can include the inlet 1766. The hourglass-shaped frame 1714 at the inlet 1766 can have an inlet diameter. The hourglass-shaped frame 1714 can include the waist 1768. The hourglass-shaped frame 1714 at the waist 1768 can have a waist diameter. The hourglass-shaped frame 1714 can include the diffuser 1770. The hourglass-shaped frame 1714 at the diffuser 1770 can have a diffuser diameter. The waist 1768 can be sized to fit within blood vessel sizes over a range of blood vessel sizes. The inlet and the diffuser accommodate anchoring the device inside a diameter of any blood vessel size, so that one size device fits all patients.

[0660] In some embodiments, the diameter of the waist 1768 is 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, 50 mm or any range of two of the foregoing values.

[0661] In some embodiments, the diameter of the inlet 1766 is 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, 50 mm, 51 mm, 52 mm, 53 mm, 54 mm, 55 mm, 56 mm, 57 mm, 58 mm, 59 mm, 60 mm, or any range of two of the foregoing values.

[0662] In some embodiments, the diameter of the diffuser 1770 is 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, 50 mm, 51 mm, 52 mm, 53 mm, 54 mm, 55 mm, 56 mm, 57 mm, 58 mm, 59 mm, 60 mm, or any range of two of the foregoing values. In some embodiments, ratio of the diameter of the diffuser 1770 to the diameter of the inlet 1766 can be a ratio of any of two of the foregoing values. In some embodiments, the inlet and diffuser ranges of dimensions, and ratios of dimensions, are important for high pump efficiency.

[0663] In some embodiments, the contra-rotating rotors 1710, 1712 are within the hourglass frame 1714. The contra-rotating rotors 1710, 1712 are driven by the motors 1706, 1708. The contra-rotating rotors 1710, 1712 are driven via flexible contra-rotating shafts 1720, 1726. The contra rotating shafts 1720, 1726 may be covered in a stationary shaft sheath 1704.

[0664] One or more components can be coated. The flexible contra-rotating shafts 1720, 1726 can be coated. The space between the catheter 1716 and the shaft sheath 1704 can be coated. The core shaft 1720 can be coated with an exterior coating. The peripheral shaft 1726 can be coated with an internal coating, an external coating, or both an internal and external coating. The shaft sheath 1704 can be coated with an internal coating, an external coating, or both an internal and external coating. The catheter 1716 can be coated with an internal coating. The device 1700 can include high-lubricity coatings. The device 1700 can be flushed or lubricated with biocompatible liquid. The device 1700 can include high-lubricity coatings and/or be flushed or lubricated with biocompatible liquid.

[0665] In some embodiments, the contra-rotating shafts 1720, 1726 are covered by a stationary shaft sheath or shaft sleeve 1704. The shaft sheath 1704 can be made of biocompatible material.

[0666] In some embodiments, the catheter 1716 is used between the motors 1706, 1708 and the hourglass frame 1714.

[0667] The contra-rotating impellers 1710, 1712 and the hourglass frame 1714 are held by the flexible shaft 1704 and collapsed inside the catheter 1716 by pushing the catheter towards the pump head in preparation for implantation. Then, the contra-rotating impellers 1710, 1712 and the hourglass frame 1714 are inserted in the vasculature until the nose cone reaches the desired anatomic location. Then, the motors and shafts are held in place with the catheter pulled towards the motors, so that the contra-rotating blades of impellers 1710, 1712 and the hourglass frame 1714 are expanded in the vasculature for use as a blood pump. After a period of use, the contra-rotating blades 1710, 1712 and the hourglass frame 1714 is again collapsed into the catheter 1716 for removal from the human body. The contra-rotating impellers 1710, 1712 can be for temporary use within the vasculature of the patient before they are explanted. Thus the device can be implanted and explanted percutaneously.

[0668] The spaces between the contra-rotating shafts 1720, 1726 can be flushed or lubricated. The spaces between the core shaft 1720 and the peripheral shaft 1726 can be flushed or lubricated. The spaces between the peripheral shaft 1726 and the shaft sheath 1704 can be flushed or lubricated. The spaces between the shaft sheath 1704 and the catheter 1716 can be flushed or lubricated. The spaces can be flushed or lubricated by a biocompatible fluid. The fluid pathways can allow fluid to escape between the two impellers 1710, 1712, and/or at shaft holders 1730, 1732, 1734. The spaces between catheter 1716 and catheter introducer 1718 may be flushed or lubricated.

[0669] In some embodiments, the two motors are intra-corporeal just downstream of the pump. Electrical power can be delivered via an intravascular power line. Electrical power can be delivered via transcutaneous electric conductors from an external energy supply.

[0670] In some embodiments, the contra-rotating blades of impellers 1710, 1712 are in a collapsible hourglass shape 1714 made of shape-memory alloy. The lattice of the hourglass frame 1714 can have segments parallel to the shafts to make the collapsed device shorter. The supporting struts 1764 of the diffuser 1770 may be straight axial struts, or a mesh or lattice, where the lattice or mesh may be as dense as the diffuser 1770 mesh or lattice.

[0671] In some embodiments, portions of the hourglass frame 1714, or the whole of the hourglass frame 1714, is covered with a biocompatible material 1774. The material 1774 can have anti-hemolytic and/or anti-thrombotic properties. The material 1774 can have drug-eluding properties. The material 1774 can be impervious to flow. The material 1774 can be partially pervious to flow. The material 1774 can include one or more openings 1776. The inlet 1766 can include one or more openings 1776. The diffuser 1770 can include one or more openings 1776. The waist 1768 can include one or more openings 1776.

[0672] The shape of the material 1774 can be used to define the maximum expansion shape of the waist 1768 of the hourglass frame 1714. The material 1774 can define the maximum radial expansion. The material 1774 can act as a corset. The material 1774 can control the gap between the tip of the impeller 1710, 1712 and the inner diameter of the waist 1768. The material 1774 can control this gap, which is a key parameter to optimize hydraulic efficiency, and minimize hemolysis. The material 1774 can be used to assist in controlling axial lengths in expanded shape. The material 1774 can be used to assist in controlling axial lengths in collapsed shape. The material 1774 can facilitate axial lengthening and radial compression. The inlet 1766 can be covered with the material 1774. The waist 1768 can be covered with the material 1774. The diffuser can be covered with the material 1774. The material 1774 acts as a shroud to the impellers 1710, 1712. The material 1774 acts as a shroud, thus improving efficiency. The material 1774 can cover the portion of the waist 1768 that surrounds the impellers 1710, 1712.

[0673] The biocompatible material 1774 plus the shape memory material of the hourglass frame 1714 create the diffuser 1770 downstream of the impellers 1710, 1712. The diffuser 1770 can have an outflow shape to improve efficiency. The diffuser 1770 can comprise a shape memory frame. The diffuser 1770 can be covered with material 1774. The biocompatible material plus the shape memory allow act to create the diffuser 1770, thus improving efficiency. The material 1774 can include one or more openings 1776 near the diffuser 1770.

[0674] The inlet 1766 can have an inflow shape. In some embodiments, the inlet 1766 is not covered by biocompatible material 1774. The inlet 1766 can be partially covered by biocompatible material 1774, thus allowing perfusion to the spinal artery and intercostal arteries. The material 1774 can include one or more opening 1776 near the inlet 1766.

[0675] The hourglass shape 1714 can be made of segments joined together. The hourglass shape 1714 can include the inlet 1766, the waist 1768, and the diffuser 1770. The inlet 1766 can be joined to the waist 1768. The waist 1768 can be joined to the diffuser 1770.

[0676] The hourglass frame 1714 or its components are connected to the shaft via supporting struts. The waist 1768, the supporting struts 1760, 1762, and the shaft holders 1730, 1732 can be integrally formed from a tubular, shape memory material. The shaft holders 1730, 1732 can be journal shaft holders and can include sleeves that cover the tubular shape memory material. The shaft holders 1730, 1732 can slide relative to one or more shafts. The shaft holders 1730, 1732 can allow the device to axially lengthen by sliding relative to the shafts. The supporting struts 1760, 1762, 1764 can be integral with shaft holders 1730, 1732, 1734. The struts 1790, 1792, 1794 can be integral with shaft holders 1730, 1732, 1734.

[0677] The waist 1768 has at least one set of supporting struts 1760 at an upstream end. The waist 1768 has at least one set of struts 1762 at a downstream end. The waist 1768 has at least one set of struts at a distal end. The waist 1768 has at least one set of struts at a proximal end. The waist 1768 has at least one shaft holder 1730 at an upstream end. The waist 1768 has at least one shaft holder 1732 at a downstream end. The waist 1768 has at least one shaft holder at a distal end. The waist 1768 has at least one shaft holder at a proximal end. The diffuser 1770 has at least one shaft holder 1734 at a downstream end. The diffuser 1770 has at least one set of struts 1764 at a downstream end. The supporting struts 1760, 1762, 1764 can be integral with the shaft holders 1730, 1732, 1734. One or more of the supporting struts 1760, 1762, 1764 can be displaced upstream when the device collapses. One or more of the supporting struts 1760, 1762, 1764 can be displaced downstream when the device collapses.

[0678] The inlet 1766 can have at least one set of struts 1790 at an upstream end. The inlet 1766 can have at least one set of struts 1790 at a downstream end. The inlet 1766 has at least one set of struts 1790 at a midpoint between the downstream end and upstream end. The waist 1768 can have at least one set of struts 1790 at an upstream end. The waist 1768 can have at least one set of struts 1792 at a downstream end. The diffuser 1770 has at least one set of struts 1794 at an upstream end. The diffuser 1770 has at least one set of struts 1794 at a downstream end. The diffuser 1770 has at least one set of struts 1794 at a midpoint between the downstream end and upstream end. The waist 1768 has at least one shaft holder 1730 at an upstream end. The waist 1768 has at least one shaft holder 1732 at a downstream end. The struts 1790, 1792, 1794 can be integral with the shaft holders 1730, 1732, 1734. The struts 1790, 1792, 1794. One or more of the struts 1790, 1792, 1794 can be displaced upstream when the device collapses. One or more of the struts 1790, 1792, 1794 can be displaced downstream when the device collapses.

[0679] The hourglass frame 1714 are connected to the shaft via at least one supporting strut 1760, 1762, 1764, at least one strut 1790, 1792, 1794, and at least one shaft holder 1730, 1732, 1734. The supporting struts 1760, 1762, 1764 and/or the struts 1790, 1792, 1794 can be integral with the corresponding shaft holder 1730, 1732, 1734. The waist 1768 can have at least one supporting strut 1760, 1762, 1764, at least one strut 1790, 1792, 1794, and at least one shaft holder 1730, 1732, 1734 at proximal end. The waist 1768 can have at least one strut 1760, 1762, 1764, at least one strut 1790, 1792, 1794, and at least one shaft holder 1730, 1732, 1734 at distal end. The diffuser 1770 can have at least one strut 1760, 1762, 1764, at least one strut 1790, 1792, 1794, and at least one shaft holder 1730, 1732, 1734 at proximal end. The diffuser 1770 can have at least one strut 1760, 1762, 1764, at least one strut 1790, 1792, 1794, and at least one shaft holder 1730, 1732, 1734 at distal end. The hourglass frame 1714 can have at least one strut 1760, 1762, 1764, at least one strut 1790, 1792, 1794, and at least one shaft holder 1730, 1732, 1734 at proximal end. The hourglass frame 1714 can have at least one strut 1760, 1762, 1764, at least one strut 1790, 1792, 1794, and at least one shaft holder 1730, 1732, 1734 at distal end.

[0680] In use, at least one of the supporting struts 1760, 1762, 1764, or at least one of the struts 1790, 1792, 1794, or at least one of the shaft holders 1730, 1732, 1734 is displaced upstream when the device collapses. In use, at least one of the supporting struts 1760, 1762, 1764, or at least one of the struts 1790, 1792, 1794, or at least one of the shaft holders 1730, 1732, 1734 is displaced downstream when the device collapses.

[0681] In some embodiments, the supporting struts 1760, 1762, 1764 are activated to collapse the whole device for implantation. In some embodiments, the supporting struts 1764 connected to the diffuser 1770 are activated to collapse the whole device for implantation. In some embodiments, the struts 1794 connected to the diffuser 1770 are activated to collapse the whole device for implantation. The supporting struts 1760, 1762, 1764 can be activated to collapse the hourglass frame 1714 for implantation. The struts 1790, 1792, 1794 can be activated to collapse the hourglass frame 1714 for implantation. The supporting struts 1760, 1762, 1764 are activated to collapse the blades 1710, 1712 for implantation. The struts 1790, 1792, 1794 are activated to collapse the blades 1710, 1712 for implantation. The collapsing of one or more supporting struts 1760, 1762, 1764, or one or more struts 1790, 1792, 1794, or one or more shaft holders 1730, 1732, 1734, blades 1710, 1712 can be moved downstream. The collapsing of one or more supporting struts 1760, 1762, 1764, or one or more struts 1790, 1792, 1794, or one or more shaft holders 1730, 1732, 1734, blades 1710, 1712 can be moved upstream. The supporting struts 1760, 1762, 1764, or one or more struts 1790, 1792, 1794, or one or more shaft holders 1730, 1732, 1734 are activated to collapse the whole device for device removal after use. The supporting struts 1760, 1762, 1764, or one or more centralizers 1790, 1792, 1794, or one or more shaft holders 1730, 1732, 1734 are activated to collapse the hourglass frame 1714 for device removal after use. The supporting struts 1760, 1762, 1764, or one or more struts 1790, 1792, 1794, or one or more shaft holders 1730, 1732, 1734 are activated to collapse the blades 1710, 1712 for device removal after use.

[0682] The collapsed hourglass frame 1714 and the blades of impellers 1710, 1712 expand in the human body for use as a blood pump. In some embodiments The shaft sleeve 1704 may be the same component as the catheter device. Recovery may be made with blades of impellers 1710, 1712 folding upstream. Recovery may be made with blades of impellers 1710, 1712 folding downstream.

[0683] The impeller blades 1710, 1712 can be made in at least two impeller segments 1750. The impeller segments 1750 of impellers 1710, 1712 can be rotated to different azimuthal orientation around their axis. The blades of impellers 1710, 1712 partially overlap to facilitate smooth folding and unfolding. The blades of impellers 1710, 1712 partially overlap so that the blades do not tangle with each other.

[0684] The blades of impellers 1710, 1712 are made from impeller segments 1750 mounted to the hub 1778. The blades of impellers 1710, 1712 are shaped into three dimensional objects with varying blade angle from hub to tip.

[0685] The blades of impellers 1710, 1712 may be made from flat plates formed into impeller segments 1750. The blades of impellers 1710, 1712 are shaped into three-dimensional objects with varying blade angle from hub to tip. The supporting structures 1780 provide shaft rigidity between shaft holders 1730, 1732. The supporting structures 1780 can have circular cross sections (like o-ring shapes) or have other shapes of different cross sectional area. The supporting structures 1780 can be configured to eliminate slow flow regions near the hubs 1778.

[0686] The flexible core shaft 1720 connects one impeller 1710 with one motor 1706 via a flexible core shaft 1720 rotating in one direction. The core shaft 1720 can have a hollow cross section. The core shaft 1720 can be covered with biocompatible coating providing lubricity. The core shaft 1720 can be covered with coating that is anti-thrombotic. The coating can be perforated or spiral or other intermittent shape. The core shaft 1720 can have solid cross section. The core shaft 1720 can be a braided wire. The core shaft 1720 can be a hollow cross section.

[0687] The other impeller 1712 is connected to the other contra-rotating motor 1708 via the flexible peripheral shaft 1726 surrounding the core shaft 1720. The peripheral shaft 1726 can be covered with biocompatible coating on inside, on outside, or both sides, providing lubricity. The peripheral shaft 1726 can be covered with coating that is anti-hemolytic or anti-thrombotic. The coating can be perforated or spiral or other intermittent shape. The peripheral shaft 1726 can be a perforated cylinder. The peripheral shaft 1726 is made of one coil, where the coil wire is a round section or a rectangular section. The peripheral shaft 1726 is made of two contra-rotating coils.

[0688] The two contra-rotating shafts 1720, 1726 can be covered with a stationary sleeve (shaft sheath or shaft sleeve) 1704. The shaft sheath 1704 can be made of PTFE, polymer, plastic, or shape memory material. The shaft sheath 1704 can be internally coated with biocompatible lubricious coating. The shaft sheath 1704 can include an anti-hemolytic or anti-thrombotic coating. The upstream tip of the core shaft 1720 can be attached to the tip extender 1722, forming the pivot point for the device collapse. The tip extender 1722 can be flexible. The tip extender 1722 can be covered by a stationary nose cone 1724. The nose cone 1724 can be attached to (or integral to a) shaft holder 1730. The shaft holder 1730 can be nonrotating. The portion of the shafts between shaft holders 1730, 1732 in the hourglass position where the blood vessel diameter is the same as the waist diameter may be rigid.

[0689] The device 1700 can include at least one fluid path to provide flushing or lubricating fluid to the flexible shafts. The device 1700 can include at least one fluid path to provide flushing or lubricating fluid between the stationary shaft sleeve 1704 and the catheter 1716. The device 1700 can include at least one fluid path to provide flushing or lubricating fluid between the stationary shaft sleeve 1704 and the peripheral shaft 1726. The device 1700 can include at least one fluid path to provide flushing or lubricating fluid between the rotating peripheral shaft 1726 and the rotating core shaft 1720. The device 1700 can include at least two fluid paths to provide flushing or lubricating fluid to the flexible shafts. In some embodiments, two or more flushing or lubricating fluid paths are combined to be supplied by one pressure or gravity bag. In some embodiments, two or more of the flushing or lubricating fluid paths may be interconnected by slits or other openings between the peripheral shaft 1726 and the core shaft 1720, between the peripheral shaft 1726 and the shaft sleeve 1704, or between the shaft sleeve 1704 and the catheter 1716. The flushing or lubricating paths between the core shaft 1720 and peripheral shaft 1726, or between the peripheral shaft 1726 and shaft sheath 1704, can have polymer or similar coating between the members. The polymer or similar coating can be a spiral 1786, arranged in a way to assist pumping of the flushing fluid by having the spiral coating act as an axial helical pump. The spiral 1786 can rotate with the core shaft 1720, thereby pumping flushing or lubrication fluid in the path between the core shaft 1720 and the peripheral shaft 1726. The spiral 1786 can rotate with the peripheral shaft 1726, or with the core shaft 1720, thereby pumping lubrication in the path between the shaft sheath 1704 and the peripheral shaft 1726.

[0690] There are several acronyms used herein, include Acute Decompensated Heart Failure (ADHF), Acute Heart Failure (AHF), Acute Heart Failure Syndrome (AHFS), Acute Myocardial Infarct (AMI), Cardiogenic shock (CGS), Cardiorenal syndrome (CRS), Cardiac Resynchronization Therapy (CRT), Heart Failure (HF), Left Ventricular Assist Device (LVAD), Mechanical Circulatory Support Device (MCSD), Percutaneous Coronary Intervention (PCI), Primary Percutaneous Coronary Intervention (PPCI), Ventricular Assist Device (VAD), and Worsening Renal Function (WRF). The device 1700 can focus on Percutaneous Coronary Intervention, High-Risk Percutaneous Coronary Intervention, Acute Decompensated Heart Failure, Cardio-Renal Syndrome, Cardiogenic Shock, bridge to VAD, and several other related maladies listed or not listed in the above.

[0691] In 2019 about 140 million people were born, and about 60 million people died globally. The leading cause of death is ischemic heart disease responsible for 16% of the number of total deaths. Ischemic heart disease is the leading cause of death in high-income, upper-middle income, and lower-middle income countries, and the third cause of death in low-income countries (behind neonatal conditions and lower respiratory infections).

[0692] Heart failure (HF) may be due to muscle dysfunction due to stiffness of the muscle, which does not allow it to relax normally, and/or dysfunction due to decreased pump function. When heart failure occurs, there is pressure transmitted back to the lungs resulting in shortness of breath and congestion. There may also be decreased output from the heart resulting in abnormal blood flow to the vital organs.

[0693] Causes of heart failure (HF) include high blood pressure (hypertension), coronary artery disease, valvular heart disease, arrhythmia, lung disease, cardiomyopathy, which can be ischemic (heart attack and/or extensive blockage), genetic, viral, and/or due to toxins (alcohol, drugs, iron, amyloid).

[0694] Symptoms of heart failure include palpitations, leg swelling, cough and/or wheezing, fatigue, weakness, weight gain (fluid retention), bloating, sometimes with decreased appetite, chest discomfort, tightness, shortness of breath (dyspnea) at rest, on exertion, lying flat, or at night, cardiorenal syndrome (CRS) including heart failure, low kidney flow, kidney failure, and/or fluid overload.

[0695] End-stage heart failure refers to stage D of the ABCD classification of the American College of Cardiology (ACC)/American Heart Association (AHA), and class III-IV of the New York Heart Association (NYHA) functional classification. These stages are characterized by a progression of heart failure despite optimal guideline-directed medical, surgical, and device therapy. Most patients with end-stage heart failure have heart failure with reduced ejection fraction (HFrEF), but patients with heart failure with preserved ejection fraction (HfpEF) may also develop end-stage heart failure.

[0696] Heart transplantation is the most effective therapy for patients with end-stage heart failure, with a post-transplant median life expectancy of about 10-15 years. Although the number of people needing heart transplants and the number of people willing to donate organs has increased, the number of heart transplants has not increased proportionately, and there has been a national decline in donor heart use. Potential recipients often have many co-morbidities and are older since the criteria for heart transplantation has few absolute contraindications, so that a fraction of the patients needing a donor heart get on the waiting list, and a fraction of those on the waiting list get a transplant. This mismatch has led to the development of LVADs as treatment alternatives or as bridge to heart transplants.

[0697] While LVADs with permanently implanted pump components have been developed for later stages of heart failure, there is increased emphasis to treat patients in earlier stages of heart-related conditions, as described below with Mechanical Circulatory Support Devices (MCSD). Some MCSD have components permanently implanted in the human body (permanent MCSD), while others have all their components permanently removed after a period of use (temporary MCSD). Moreover, the LVAD population is chronically sick, whilst those requiring temporary support make up those patients who will recover from their acute illness, as well as those patients who may move on to be considered for more invasive forms of support including Cardiac Resynchronization Therapy (CRT), LVADs and cardiac transplantation.

[0698] AHFS is defined as gradual or rapid change in heart failure (HF) signs and symptoms resulting in a need for urgent therapy. These symptoms are primarily the result of severe pulmonary congestion due to elevated left ventricular (LV) filling pressures (with or without low cardiac output). AHFS can occur in patients with preserved or reduced ejection fraction (EF). Concurrent cardiovascular conditions such as coronary heart disease (CHD), hypertension, valvular heart disease, atrial arrhythmias, and/or noncardiac conditions (including renal dysfunction, diabetes, anemia) are often present and may precipitate or contribute to the pathophysiology of this syndrome.

[0699] The various pathogeneses of Acute Heart Failure (AHF) and Acute Decompensated Heart Failure (ADHF) are described: “Patients admitted with HF exhibit a wide spectrum of disease and range from those with severe LV systolic dysfunction and low cardiac output to those with severe hypertension and normal or near-normal LV systolic function. The majority of patients with AHF lie between these extremes and therefore also demonstrate a distribution of underlying pathology and precipitants, leading to the common endpoint of fluid overload . . . . Patients with ADHF typically present with mild-moderate symptoms whereas those patients with AHF and pulmonary oedema (III) have a clinical presentation dominated by respiratory distress and hypoxaemia and display a continuum of severity from low-output states (Iva) to outright cardiogenic shock (Ivb)”.

[0700] Acute decompensated heart failure (ADHF) is the worsening of symptoms of heart failure requiring unplanned office visits, emergency room visits, or hospitalization. It is usually, but not always, caused by cardiogenic pulmonary edema with rapid fluid accumulation in the lungs. In ADHF hypertension, ischemia, and/or ventricular dysfunction decrease cardiac output. This activates the neurohormonal pathway. The sympathetic system increases norepinephrine to improve peripheral perfusion via vasoconstriction. This in turn activates the renin-angiotensin-aldosterone system to increase renal perfusion through water retention. The increase in left ventricular filling pressure causes protein-poor fluid to leak into the lung alveoli and interstitium. The autoregulation system increases heart rate and systemic vascular resistance to improve cardiac output; and as a result an unstable cycle spiraling to worsening condition is established. ADHF results in systemic and pulmonary congestion due to increased left- and right-heart filling pressures.

[0701] Worsening renal function (WRF) is common during the treatment of heart failure (HF). These are urgent and difficult to treat cases, with high mortality rates and recurring readmissions. As reported “WRF has been associated with decreased survival, hospitalization, and disease progression. There are several hypothetical mechanisms, including inflammation, oxidant stress, or induction of apoptosis by uremic toxins, by which a reduction in renal function could directly lead to mortality. However, patients who experience WRF also often exhibit multiple markers of increased HF disease severity and are less likely to respond to diuretics. As a result, it is difficult to determine whether the frequently observed association between WRF and adverse outcomes results directly from the reduction in glomerular filtration rate (GFR) or is merely serving as a marker of greater HF disease severity”.

[0702] The prognostic role of worsening renal function (WRF) during hospitalization for acute decompensated heart failure remains controversial. As reported, “WRF is reported in approximately 25% to 40% of acute decompensated heart failure patients. WRF is usually, but not always associated with worse outcomes in patients with heart failure. Transient WRF accompanied with hemoconcentration, effective decongestion strategies, and initiation of appropriate medical treatment for heart failure with angiotensin-converting enzyme inhibitors or mineralocorticoid receptor antagonists is not associated with worse outcomes . . . . During hospitalization, treatment should focus on the patient's clinical status, resolution of symptoms and signs of congestion rather than temporary changes in renal function . . . .”

[0703] Cardio-renal syndrome (CRS) is defined as “Cardiorenal syndrome encompasses a spectrum of disorders involving both the heart and kidneys in which acute or chronic dysfunction in one organ may induce acute or chronic dysfunction in the other organ. It represents the confluence of heart-kidney interactions across several interfaces. These include the hemodynamic cross-talk between the failing heart and the response of the kidneys and vice versa, as well as alterations in neurohormonal markers and inflammatory molecular signatures characteristic of its clinical phenotypes.”

[0704] Cardiogenic shock (CGS) is the condition where the heart suddenly cannot pump enough blood and oxygen to the brain, kidneys, and other vital organs, and is a serious medical emergency. CGS is rate, but fatal if not treated immediately. The most common cause of cardiogenic shock is a heart attack (when one or more of the coronary arteries becomes blocked). Other health problems that may lead to CGS are heart failure; chest injuries; medicine side effects; and conditions that prevent blood from flowing freely through the blood circulation system, such as clots. Mortality is 50%.

[0705] Percutaneous Coronary Intervention (PCI), previously known as coronary angioplasty, is a procedure that enlarges the diameter of coronary arteries that have been narrowed by atherosclerosis (plaque buildup in the artery). Techniques used in PCI are balloon angioplasty, angioplasty to place a stent, laser angioplasty, and rotational atherectomy. The technique has been extended to include the treatment of patients suffering an acute myocardial infarction (AMI), usually during the first 6 hours after onset of chest pain. The technique is called Primary Percutaneous Coronary Intervention (PPCI) and may be undertaken in patients with overt or impending hemodynamic instability and therefore is often supported by temporary cardiovascular devices.

[0706] Statistics includes 20% of adults will develop heart failure in their lifetime. Statistics includes 960,000 new heart failure cases each year. Statistics includes 24% of hospitalized for heart failure patients randomized in the United States were readmitted within 30 days of discharge despite the fact that the majority were treated with evidence-based treatments and had early post-discharge visits. Statistics includes that kidney function is a key determining factor. The glomerular filtration rate is reduced in most patients with heart failure. Statistics includes renal dysfunction occurs in up to 64% of ADHF hospitalizations with 1.8 m hospitalizations per year due to HF. Statistics includes over 300,000 related deaths in the US annually. Statistics includes over $100b spent each year worldwide on heart failure. Statistics includes in about 40% of HF hospitalizations patients are discharged still congested.

[0707] There are differences between VADs (heart assist pumps with permanently installed components in the human body and directly connected to the native heart) and MCSD (heart assist pumps for temporary use with fully removable components). Contra-rotating impellers can be located anywhere in the aorta. There are efficiency and hemolysis advantages of contra-rotating blades. There are advantages with magnetic blades. There are advantages with non-magnetic blades. There are advantages with an hourglass shape, wherein each segment of the hourglass can be defined, such as the inlet, waist, diffuser.

[0708] Blood perfusion requires two numbers to be fully specified: blood pressure rise and flow rate. Without both numbers, definition of the perfusion advantage of any pump is incomplete. In the average adult human body, the blood flow rate at rest is about 5 lt/min, and the left ventricle adds 120 mmHg in pressure from upstream to downstream at the ejection phase. Continuous flow turbomachine LVAD designed for specifications about 120 mmHg and 5 lt/min with diameters under 5 mm are optimal when they are of centrifugal geometry, while LVAD and MCSD designed for 5 lt/min and less than about 50 mmHg tend to be axial screw type or axial propeller-type turbomachines. This is analogous to water pumps, where for the same flow rate, higher pressure pumps are centrifugal and of lower rpm; and lower pressure pumps are axial and of higher rpm.

[0709] FIG. 193 illustrates the flow of blood in the human circulation system. The flow of blood can be conceptually considered as tracing a continuous-flow figure-eight loop, as shown in FIG. 193. The four chambers of the heart are represented by LA, LV, RA and RV respectively. The four heart valves open and close at different times. The effects of the arterial system, the venus systems, and the organs present resistance, capacitance, damping and stiffness to the blood flow. Thus, the circulation system can be considered as an open continuous-flow system illustrated in the figure-eight loop as shown. Within this figure-eight loop, in-series blood-pump assist action can be possible at any point in the human circulation system. In some embodiments, a left-heart (arterial flow) MCSD can have inherent physiological advantages in the ascending or descending aorta.

[0710] In the in-series configuration of MCSD in the figure-eight loop, the flow rate of the pump can be equal to that required by the circulation system (nominally 5 lt/min). In this configuration, the flow rate going through the LV can be the same as the flow rate going through the MCSD. In this configuration, part of the nominal pressure rise (120 mmHg) is provided by the native but diseased LV, while the remaining pressure rise is provided by the MCSD. Thus, the desired nominal design-point specification for the MCSD can be 5 lt/min and less than 50 mmHg, wherein the native LV can provide the remaining 50-70 mmHg. This flow rate and pressure rise requirement provided by a small diameter pump can utilize axial-flow turbomachines.

[0711] Within the geometric diameter constraints of MCSD temporary installation and removal, it may be difficult to arrange for an axial-flow single-impeller propeller-type turbomachine to provide 5 lt/min and pressure rise above 20 mm Hg at rpm below 12,000. This is corroborated by the pump performance curves as described herein. Axial screw-type turbomachines can provide slightly higher pressure rise than 20 mm Hg, but they do not have a contra-rotating impeller to remove the flow vortex generated by the first rotor. In order to exceed 50-70 mm Hg and within the constraints of MCSD, the design may require use centrifugal turbomachines, like many VADs, and these may be harder to implement as removable MCSD.

[0712] Once the MCSD pressure rise and flow rate at design point have been specified, the next limiting parameter is the pump diameter. For percutaneous implantation and removal, the axial pump diameter must be small, which in turn dictates higher rpm. This explains why most of the MCSD described herein have higher rpm than the device 1700. Higher rpm causes increased hemolysis and subsequent blood trauma. In order to reduce pump rpm, and the resultant hemolysis, the designer must increase the diameter, thus causing a conflicting requirement with percutaneous implantation and removal of the MCSD.

[0713] Referring to FIG. 194A-194E, the impellers can be positioned in ducts. The concept can be applied to installation of an impeller pump in an artery or vein in the vascular system. In FIG. 194A, the impeller and duct are of larger diameter than in FIG. 194B. For the same pressure rise and flow rate, the larger-diameter impeller of FIG. 194A will be more efficient and will operate at lower rpm than the smaller-diameter impeller of FIG. 194B. In part the efficiency of FIG. 194A is higher than of FIG. 194B because the axial boundary layer thickness along the duct interior diameter takes a bigger proportion of the blade radial length (called the blade height) in FIG. 194B than in FIG. 194A. The mechanisms by which the blades of the axial turbomachine pump are foldable for implantation is described herein, thus allowing design of higher impeller diameter, and correspondingly lower rpm.

[0714] Thus design of MCSD for temporary implantation and full removal imposes substantial design challenges. Installation with minimally-invasive surgery requires small-diameter impellers, which must rotate at high rpm in order to make the desired combination of perfusion (pressure rise and flow rate). Few of these temporary devices specify the combination of pressure rise, flow rate, pump efficiency, and rpm at which the perfusion performance is attained. The reason is that the small impeller diameters deliver relatively small pressure rise at relatively high impeller rpm, with the high rpm creating concerns for the hemolytic performance of the pump. In general terms, the smaller the pump diameter, the higher the rpm. For instance, among the MCSD described herein, some devices have impeller diameters of the order of 5 mm or less, and rotate at speeds of 30,000 to 50,000 rpm. For instance, among the MCSD described herein, some devices have 24 Fr operating profile, which is collapsed in a 14 Fr catheter, and the approximately 7-8 mm diameter screw-type axial impeller operates at 20,500 rpm to deliver 5 lt/min at 60 mmHg.

[0715] The device 1700 is described herein. The vast majority of adult males and females have descending-aorta diameter between 20 and 35 mm. The impeller diameter of device 1700 can be about 18 mm (+/−5 mm), so that the unfolded impeller can be installed in practically all adult humans. The blades are propeller-type turbomachines. These turbomachines have differences from screw-type. The propeller-type turbomachines facilitate folding for implantation and removal of the blades in the axial direction. The propeller-type turbomachines allow the folded diameter of the device to be smaller than 18 mm for implantation and removal. With the contra-rotating blades of device 1700, the downstream impeller 1712 removes (or substantially removes) the vortex imparted by the upstream impeller 1710. With the contra-rotating blades of device 1700, the removal of the vortex thus imparts the energy from the two impellers 1710, 1712 to downstream-pointing flow rate and pressure rise. This removal of the vortex enables the device 1700 to achieve 5 lt/min and 20-40 mmHg at 5,000-15,000 rpm. The smaller the gap between the impeller tips 1710, 1712 and the waist 1768 of the hourglass frame 1714 as described herein, the lower the rpm. For hemolysis optimization, and to minimize regurgitant flow around the tip of the rotating impeller 1710, 1710, the gap can be 0.1 to 1.5 mm, nominally around 0.5 mm.

[0716] Another limiting factor in the design of MCSD is the diameter of the inlet and outlet flow plenum in which the pump is operated and tested. For instance, a 19 mm diameter impeller pump tested in a 19 mm (plus tip clearance) diameter inlet and outlet duct flow circuit, as shown in FIG. 194A, can provide a certain level of tested performance. The performance can include attributes at various pump operating rpm such as pressure rise vs. flow rate, and efficiency vs flow rate curves. As explained herein, a 5 mm diameter impeller pump tested in a 5 mm (plus tip clearance) diameter inlet and outlet duct flow circuit, as shown in FIG. 194B, will provide a different and lower level of tested performance. The level of tested performance in FIG. 194B above will be substantially reduced if this pump is installed in a blood vessel of 20-35 mm diameter at pump inlet, with a sudden contraction to 5 mm and expansion back to 25-30 mm at outlet FIG. 194C. The pump performance will be worse in FIG. 194C than in FIG. 194B because the difference in impeller and duct diameters can cause pump inlet and pump outlet flow losses. The pump performance will be worse in FIG. 194C than in FIG. 194B because additional turbulence and hemolysis due to flow-inlet effects, flow disturbance effects, and flow vortices at the outlet region. The tested pump performance of this pump in a 5 mm duct in FIG. 194B can be better than the tested performance in a varying-diameter duct in FIG. 194C as described herein. Similarly, if a pump of 5 mm diameter is installed in a 25-30 mm constant-diameter passage, and it pumps additional blood flow by entrainment around the pump perimeter, whether the pump is in a casing/housing/shrouded as shown in FIG. 194D, or is not in a casing/housing as shown in FIG. 194E. There will be additional outlet-flow disturbance by entrainment and recirculation effects, further reducing the pump performance from that in FIG. 194B. Of course if a smaller-diameter pump is installed across the aortic valve, the flow regime is as in FIG. 194C when the aortic valve is closed, and as in FIG. 194D when the aortic valve is open.

[0717] The geometries of other devices described herein are introduced across the aortic valve. At pump inlet and pump outlet, the available flow diameter is higher than the pump diameter. When the aortic valve is closed, the flow regime is as in FIG. 194C. When the aortic valve is open, the flow regime is as in FIG. 194D. The flow regime of other devices, installed in the descending aorta and described here, is as in FIG. 194D above. The other device has impeller diameter larger than 5 mm but smaller than 20 mm. It is installed in the descending aorta in a substantially-open casing, is as in FIG. 194E.

[0718] FIG. 195 is an indication of the type of entrainment, vortices and flow losses introduced when a smaller diameter impeller is introduced in a larger passage. This flow regime is representative of a single-impeller axial-flow pump when it is installed in a concept configuration analogous to the previous pump-in-duct flow, top of FIG. 194D.

[0719] FIG. 196A-196E correspond to parts 194A-194E of the pump-in-duct flow regimes described herein. FIG. 196A illustrates the hourglass geometry of device 1700 via which the 18-20 mm impellers 1710, 1712 are operating in the waist 1768 with minimal clearance between the flow duct and the impeller tips. The biocompatible material 1774 around the hourglass frame 1714 allows application of the highest-efficiency FIG. 194A flow concept in vascular-vessel diameters approximately 18-35 mm. FIGS. 196B-196C are illustrations of other devices installed across the aortic valve. FIG. 196D illustrates another device corresponding to a smaller diameter impeller in a substantially open housing installed in a larger diameter duct.

[0720] It may be crucial to identify in what test-rig geometry the pump performance characteristics of such other device FIGS. 196B-196D have been obtained. The effect of deteriorating performance as the duct diameter is increased from the pump-impeller diameter is shown in the measured test performance of other devices.

[0721] A heart-assist blood pump 1700 is described herein. The device 1700 can be designed for temporary use in PCI, PPCI, WRF, CRS, CGS, AHF, ADHF, post cardiac surgery, cardiovascular conditions with similar symptoms. The device 1700 can be designed for a preventive measure to delay the need for permanent LVAD implantation. The blood flow through the device 1700 is optimized, and the rpm is minimized, by the use of contra-rotating blades of impellers 1710, 1712 in a hourglass-shaped duct 1714 with waist 1768, inlet 1766, and diffuser 1770.

[0722] The hourglass frame 1714 can be covered with biocompatible material 1774 to guide the flow through the impeller duct. The hourglass frame 1714 can be covered with biocompatible material 1774 to provide perfusion for the intercostal and spinal arteries via openings 1776. The waist 1768 of the hourglass frame 1714 allows optimization of the gap between the impeller tips 1710, 1712 and the inner diameter of the waist 1768 of the hourglass frame 1714, as described herein. In some embodiments, the design 1700 is a one size fits most patients. The design can include contra-rotating non-magnetic blades, 1710, 1712. The design can include specific inlet dimension ranges, waist dimension ranges, diffuser dimension ranges, and hourglass dimension ranges. As described herein, there can be an improved manufacturing process for the hourglass frame 1714. The device can include a biocompatible coating of material 1774 for the hourglass frame 1714. The design can include the shape and number of the blades for impellers 1710, 1712 for smooth folding. The design can include the shape 1780 between the hub 1778 and the blades of impellers 1710, 1712 for folding using Nitinol properties. The design can include the contra-rotating motors internal or external to the vasculature of the patient. The design can include the flexible drive shafts 1720, 1726 and their cover or shaft sheath 1704. The design can include the three flushing/lubrication paths. The design can include the catheter 1716 use for implantation and removal.

[0723] The device 1700 is designed to reduce cardiac workload and increase renal and other-organ perfusion. Upstream of the pump, the device 1700 reduces heart afterload and increases cardiac output. Downstream of the pump, the device 1700 increases renal perfusion, where this means augmentation of the combination of flow and pressure.

[0724] The device 1700 is installed in the folded position in the ascending or descending aorta. The device 1700 is installed and then the pump-head components are unfolded in place. Then, the pump is operated for a period of time. As a result of the operation, the heart symptoms described above are alleviated. After a period of use, the pump-head and all device components are fully removed from the human body. The device may also be used as a bridge (a new pathway) to LVAD implantation.

[0725] The location of the device 1700 in the descending or ascending aorta does not affect negatively coronary, carotid, or brachiocephalic perfusion. The specifications of the blood pump, including blood pressure rise and flow rate, have been optimized between healthy heart, diseased heart, and blood pump specifications

[0726] Recent reviews are available for LVAD and MCSD technologies. All blood-assist pumps that are permanently installed and are directly attached to the native heart are called Ventricular Assist Devices (VADs). In recent years, there has been increased interest in miniature heart-assist pumps that are fully-removed after a period of use, called Mechanical Circulatory Support Devices (MCSD). Some MCSD are designed for implantation with minimally invasive surgery. MCSD devices are frequently compared in performance with Extra-Corporeal Membrane Oxygenation (ECMO) or a temporary external continuous flow LVAD.

[0727] Some MCSD are attached to or implanted in the native heart or installed across the aortic valve. Others are attached to the vasculature away from the native heart. Some MCSD have larger-diameter blades that are foldable to facilitate implantation via the vascular system. Some MCSD have very small diameter impellers in a small diameter casing to facilitate implantation. The devices described herein have advantages over other devices.

[0728] FIG. 196B-196C illustrate a small diameter screw-type high rpm axial turbomachine device installed percutaneously across the aortic valve. The pump inlet is in the LV and the pump outlet is in the ascending aorta. With the aortic valve in the open or closed position, the difference between the velocity of blood at the outlet of the pump and the surrounding blood vessel causes fluid entrainment of the surrounding flow around the pump outlet. The small diameter of the pump requires high rpm. The high rpm leads to high hemolysis levels. The entrainment leads to additional flow mixing and turbulence, resulting in additional hemolysis. Therefore, all such devices with low diameter compared to the cardiovascular passage require high rpm and result in high hemolysis from the high rpm and the additional flow losses due to the geometry of the flow.

[0729] Recent publications about this device discloses flow rates, but does not disclose the corresponding pressure rise achieved, and thus fail to completely disclose the level of perfusion (the combination of pressure rise and flow rate) achieved at the operating rpm and in the operating geometry. As described above, design point or nominal operating point pressure rise and flow rate, as well as impeller diameter and impeller rpm, are essential specifications for all blood pumps.

[0730] Sample performance curves for early prototypes of this device tested in typical pump-test facilities indicate less than 10 mm Hg at 5 lt/min and over 30,000 rpm. This combination of pressure and flow was tested in-vitro in a standard pump-performance flow rig, without disclosing the pump inlet and outlet plenum geometry. As mentioned above, the discharge from this into the larger-diameter ascending aorta causes additional flow friction, pump losses, and hemolysis. Later publications, indicate this device devices operate between 31,000 rpm and 51,000 rpm, providing flow rates between 2.5 and 5.0 lt/min, but they do not disclose the corresponding pressure rise. Publications show general effects of the pump on left ventricular end diastolic pressure, but do not specify the pressure rise and flow rate, i.e. the complete specification of the perfusion assistance provided by the device of FIG. 196B.

[0731] FIG. 196C illustrate a collapsible elastomeric screw-type impeller in a self-expanding stent frame. It is inserted into the femoral artery in the thigh and threaded up through the body into the left ventricle. A 13 Fr sheath is introduced through aortic valve and expands to 24 Fr. Inlet in LV, outlet in ascending aorta. It has similar limitations to those described for the device of FIG. 196B. In comparison to FIGS. 191 and 192, its tested performance indicates 5 lt/min and 30 mmHg at 18,000-20,000 rpm.

[0732] FIG. 196D illustrate a two-bladed impeller of tip diameter about 15 mm in the deployed position, encased in a plastic cage, and installed in the descending aorta. The blades are airfoil shapes of solid (rigid) metal, where the blades are folded via a mechanical hinge mechanism at their hub. The impeller is installed in a plastic cage, which is of smaller diameter than the descending aorta. It is installed via a 10 Fr catheter. The device provides about 3.5 lt/min at 14,000 rpm. An earlier publication indicates that pump performance is decreasing with increasing diameter of the descending aorta, and that in a test tube of diameter 26 mm at 14,000 rpm the pump produced 5 lt/min and about 14 mmHg. There are other expandable pumps including Screw-type single axial impeller followed by stator blades, with performance 18 mmHg at 7,000 rpm.

[0733] FIG. 195 illustrates a 6 mm diameter device delivered via catheter. This is a small-diameter screw-type axial impeller driven by a small-diameter motor. Installed in the descending aorta and relying on flow entrainment, and corresponding flow losses, turbulence and hemolysis. The flow is dominated by the vortex pattern downstream of the impeller.

[0734] Little is known about other devices. Some devices include its impeller elongates during collapse. The device can be installed in the LV across the aortic valve, entrainment in ascending aorta. The device can be an axial flow pump installed in the Inferior Vena Cava, with two sealing elements above and below the kidneys. The device can sucks pressure out of veins of kidneys. Some device can include axial screw-type pumps installed in cages in blood vessels. Devices can include an ultra-miniature endovascular pump to deploy percutaneously for the treatment of advanced heart failure. Devices can include low profile catheter pump. Devices can include Percutaneously-installed pump for high-risk patients. Devices can include balloons for insertion in the vasculature.

[0735] The device 1700 can include gentle high flow/low shear primary path, with less than 1% of blood traverses higher shear bearing paths (the strut holders 1730, 1732 and 1734 are designed for continuous outflow of flushing/lubricant into the blood stream, so there should be no blood going through bearing surfaces). The device 1700 can enable percutaneous delivery and endovascular deployment. The device 1700 can have an efficient design which preserves high flow capacity relative to diameter. The device 1700 can have the lowest hemolysis. The device 1700 can have hemocompatibility. The device 1700 can have miniaturization. The device 1700 can have cost effectiveness.

[0736] FIGS. 197A-197D is a view of the device 1700. FIG. 197A is a view of the device 1700 expanded. FIG. 197B is a view of the device 1700 collapsed. FIG. 197C is a view of the device 1700 expanded. FIG. 197D is a view of the device 1700 expanded. The device 1700 can include the peripheral shaft 1726. The device 1700 can include the shaft sleeve 1704. The device 1700 can include the catheter 1716. The device 1700 can include the catheter introducer 1718. The catheter introducer 1718 can be in femoral artery. The motor drive and controller can be outside. The motor drive can be two contra-rotating motors. The motor drive can be a motor and gearbox.

[0737] In some embodiments, there are an equal number of blades in the two impellers. In some embodiments, there are different number of blades in the upstream and downstream impeller. In some embodiments, the number of blades in each rotor is a prime odd number. In some embodiments, one impeller has an even number of blades and one impeller has an odd number of blades. In some embodiments, both impellers have an even numbers of blades. In some embodiments, there are 2, 3, 4, 6, 7, or 8 impeller segments. In some embodiments, the impeller segments are azimuthally positioned with mechanical fixing arrangements, and carry torque with the mechanical fixing arrangement too. In some embodiments, the holes in membrane may be oval, or rhomboid, follow the nitinol lattice, or can be any other shape. In some embodiments, the holes in biocompatible membrane may be in the inlet, or diffuser, or waist segment.

[0738] In some embodiments, the supporting structure 1780 or curvature controller is placed to limit the combination of bending and torsion stresses and strains, so the collapsed structure remains in the elastic regime. In some embodiments, the bending direction of collapsed components is mechanically secured to fall between the rolling direction of shape-memory alloy sheets and the direction perpendicular to the rolling direction, to even out deformations, stresses, and local forces during collapsing and expanding.

[0739] In some embodiments, the flex shafts from the motors all the way to the tip extender are fixed length, and the catheter is configured to be advanced by folding the hourglass and blades, the nose cone moves a little upstream, and the device collapses. In some embodiments, the space between the flexible contra-rotating shafts or between the flexible contra-rotating shafts and a shaft sheath or between the shaft sheath and a catheter or between the catheter and a catheter introducer are lubricated or flushed by a biocompatible fluid. In some embodiments, the shape-memory alloy forms a lattice of the collapsible hourglass shape, wherein the lattice comprises segments parallel to the centerline of the hourglass to make the collapsed device shorter. In some embodiments, portions of the hourglass frame, or the whole of the hourglass frame, or the waist, or the waist and the diffuser, or the waist and diffuser and inlet, is covered with a biocompatible material. In some embodiments, the hourglass frame or the segments are connected to a shaft via struts or any supporting structure such as struts.

[0740] In some embodiments, the struts or any supporting structure such as struts are integral with a tube. In some embodiments, a waist of the hourglass frame comprises at least one set of struts or any supporting structure such as struts at a proximal or a distal end. In some embodiments, a waist of the hourglass frame comprises a set of struts or any supporting structure such as struts at a proximal end and a set of struts or any supporting structure such as struts at a distal end. In some embodiments, a diffuser of the hourglass frame comprises at least one set of struts or any supporting structure such as struts at proximal or distal end. In some embodiments, the hourglass frame comprises at least one set of struts or any supporting structure such as struts, tube, or shaft holder at proximal or distal end. In some embodiments, at least one set of struts or any supporting structure such as struts, tube, or shaft holder is displaced upstream when the device collapses. In some embodiments, at least one set of struts or any supporting structure such as struts, tube, or shaft holder is displaced downstream when the device collapses. In some embodiments, at least one set of struts or any supporting structure such as struts is activated to collapse the whole device for implantation. In some embodiments, at least one set of struts or any supporting structure such as struts is activated to collapse the hourglass for implantation. In some embodiments, at least one set of struts or any supporting structure such as struts collapses the waist segment, which in turn collapses the blades for implantation. In some embodiments, the collapsing struts or any supporting structure such as struts, shaft holders and/or blades move upstream or downstream. In some embodiments, the struts or any supporting structure such as struts are activated to collapse the device for removal after use. In some embodiments, at least one strut or any supporting structure such as struts is activated to collapse the hourglass frame for removal after use. In some embodiments, at least one strut or any supporting structure such as struts is activated to collapse the blades for removal after use. In some embodiments, supporting struts or any supporting structure such as struts are made of lattice of the same density as the hourglass frame. In some embodiments, at least one strut or any supporting structure such as struts is activated to collapse the blades for removal after use or by the radially-collapsing waist segment, which is collapsed by the radially-collapsing diffuser, which is collapsed by the diffuser strut.

[0741] In some embodiments, the at least two blade-carrying assemblies are rotated to different azimuthal orientation around their axis or impeller segments or blade carrying assemblies are held in specific azimuthal orientations by indexing shapes and recesses. In some embodiments, the blades are made from an airfoil mounted to the hub or three-dimensional varying thickness airfoil mounted to the hub via hub-blade interconnect. In some embodiments, a flexible shaft connects one impeller of the at least two contra-rotating non-magnetic impellers with one motor via a core shaft rotating in one direction or wherein the core shaft is covered with biocompatible lubricious coating. In some embodiments, a portion of shafts between a first shaft holder and a second shaft holder is rigid. In some embodiments, the device comprises a polymer or similar coating between members within a flushing and/or lubricating fluid path between a peripheral shaft and a core shaft, between the peripheral shaft and a shaft sleeve, between the shaft sleeve and a catheter, or between the catheter and a catheter introducer.

[0742] In some embodiments, a biocompatible membrane is deposited around the perimeter as a spiral tube of biocompatible material, or it can be a weave sputtered around. In some embodiments, the two coaxial contra-rotating motors comprise at least one intracorporeal motor, or one intracorporeal motor, or two intracorporeal motors. In some embodiments, the device comprises an impeller interconnect sleeve. In some embodiments, the impeller interconnect flexible sleeve allows bending of the device for percutaneous placement in the blood vessel.

[0743] In some embodiments, the shaft holder are configured to prevent blood ingress into the shaft holder or wherein the flush flow prevents blood flow into the shaft holders, the nose cone, the impeller interconnect, and between shaft sleeve and catheter, wherein the groves help further. In some embodiments, the device comprises a shaft holder comprising interior grooves and exterior grooves configured to control the flow rate and direction of flow of the flush and/or lubricant between concentric components or configured to direct flush flow and prevent blood flow in, where parts do not need to be concentric.

[0744] In some embodiments, the device can include a slot in a peripheral shaft configured for passing flush and/or lubricant from inside the peripheral shaft into the space between peripheral shaft and a shaft holder or wherein the peripheral slots allow flow to a shaft sleeve and to a peripheral perforated tube at tip extender. In some embodiments, grooves at the two ends of shaft holder limit the amount of flush and/or lubricant needed and impart velocity to the outgoing fluid or wherein the grooves are in several components including a nose cone and a shaft holder. FIG. 198 illustrates the blade folding arrangements in relation to rolling direction in the manufacture of nitinol sheets. In some embodiments, the impeller segments 1750 are formed from nitinol sheets, which may be rolled into flat sheets. In some embodiments, the blades 1758 of the impeller 1710, 1712 fold upstream along the axis of the hubs 1778. In some embodiments, the blade chords fold by wrapping around the axis of the hubs 1778. The rolled nitinol sheets exhibit slightly different stress strain relation in the direction of rolling from the direction perpendicular to it. In other words, if x is along the direction of rolling and y is the direction perpendicular to the direction of rolling, the stress strain relationships of the nitinol sheets are slightly different in the x and y directions. This difference in the stress strain relationship may result in different bending patterns at the most strained component, the hub-to-blade connector 1788. This difference in the stress strain relationship may result in different folding patterns across the chord of different blades around the perimeter of the impellers 1710, 1712.

[0745] Thus, the direction of the radial line from the center of the impeller portion 1750 along the hub-to-blade connector 1788, must be carefully selected in relation to the azimuthal location of the indexing cuts 1791 on the hubs of the impeller portions 1750, and in relation to the rolling direction of the nitinol sheets. The indexing cuts 1791 are shown in relation to a center of the impeller portion 1750. The optimal azimuthal positioning will be different for 6-bladed and different for 8-bladed impellers. The top figures in FIG. 198 show one example of how such choices in azimuthal orientations can be made to distribute stress-strain relations 6-bladed impellers and the hub-to-blade connector 1788. The bottoms figures in FIG. 198 show one example of how such choices in azimuthal orientations can be made to distribute stress-strain relations 8-bladed impellers and the hub-to-blade connector 1788. The blue lines mark the direction of the hub-to-blade connector 1788 in relation to the azimuthal location of the indexing recess cuts at the hubs and the direction of rolling of the nitinol sheets.

[0746] In this example, in the 6-bladed impeller the hub-to-blade connector 1788 is 15 degrees counterclockwise from the rolling direction, and the first hub recess is 15 degrees clockwise from the rolling direction. In this example, in the 8-bladed impeller, the hub-to-blade connector 1788 is 45 degrees counterclockwise from the rolling direction, and the first hub recess is 22.5 degrees counterclockwise from the rolling direction. All of the hub-to-blade connector 1788 are at an intermediate angle from the rolling direction. All of the blade chord directions are at an intermediate angle from the angle of the hub-to-blade connector 1788 and from the rolling direction and a direction perpendicular to the rolling direction. There are other optimal locations as well, and they will be different for impellers with different number of blades. In some embodiments, highly stressed components (such as the hub-to-blade connector 1788 and the blade chords) are placed in relation to rolling direction in a manner that minimizes the effect of differences between stress-strain curves along the direction of rolling and a direction perpendicular to the direction of rolling. In some embodiments, the indexing recesses or other methods are used to place stressed components in relation to rolling direction in a manner that minimizes the effect of differences between stress-strain curves along the direction of rolling and a direction perpendicular to the direction of rolling.

[0747] FIGS. 199-202 illustrate the nitinol components staying in an elastic regime with shape supports. FIG. 199 represents a typical stress-strain distribution of nitinol in repeated loading and unloading cycles of increasing strain at one specific operating temperature. The dotted black line in the top graph illustrates the concept of the limiting region, below which the stress and the strain are such that the nitinol made parts remain in the elastic regime, i.e. recover their shape after the load is removed. At this temperature, the limiting strain is about 8% and the limiting stress is about 700 MPa. If the folding assembly is to remain in the elastic regime, the combined strain must not exceed 8%, and the corresponding combined stress will be about 700 MPa.

[0748] The blades 1758 are 3D objects with substantial variations in blade angles and surface curvature along the blade length. FIG. 199 shows flat plate circle 1779 with indexing recess slots 1791, and the 3D shape of the hub-to-blade connector 1788 up to the region where the 3D shape of blades 1758 begins. Thus hub-to-blade connector 1788 is the part that will fold to collapse the device inside a catheter. It is a 3D shape starting from a flat plate near the flat plate circle 1779, and a 3D shape where it approaches the shape of the blade 1758. As the device 1700 is folded into the catheter, the hub-to-blade connector 1788 bends and twists concurrently along the axis of the hub. Thus, the hub-to-blade connector 1788 is a region of high bending and torsional strain, which must not exceed ε.sub.max=8% strain to remain elastic. The resultant combined maximum stress σ.sub.max, in this example 700 MPa, is derived from the dotted black line in the graph, where the corresponding maximum elastic strain is ε.sub.max=0.08 (8%).

[0749] If this hub-to-blade connector 1788 was a flat plate of half thickness c, subjected to plane 2D bending resulting in the plate assuming a radius R, the resultant equation connecting these to strain ε is

R=c/ε.

[0750] Thus there is minimum radius of curvature that must not be exceeded for the component to stay in the 8% elastic strain regime, and this is related to a maximum plate thickness h=2c (h is plate thickness, c is the half thickness).

[0751] The above equation results in the concept that for a given plate thickness 2c and for a shape that is only bending, there is a need for a constant curvature device like the support structure 1780 in FIG. 183C, around which to bend the flat hub-to-blade connector 1788 of the collapsing blades 1758 and remain in the elastic regime. However, the hub-to-blade connector 1788 is a 3D shape, which has a twist angle along its length. This results in a known amount of twist angle and resultant twist strain of varying magnitude along the length of the hub-to-blade connector 1788 as the blade 1758 collapses upstream against the shaft length, that can be computed from the geometry of the hub-blade connector 1788. In some embodiments there may also be other components of strain in the hub-blade connector 1788. In some embodiments, a varying curvature device of the support structure 1780 is placed, around which the length of hub-to-blade connector 1788 will be guided to bend, so that the combined strain does not exceed 8%. The curvature of the support structure 1780 can vary to meet this maximum combined strain criterion.

[0752] In textbooks the total equivalent strain (that must not exceed 8%) for the elastic, plastic, creep and thermal strains is computed using the von Mises equation

[00001]${\epsilon }_{\epsilon q}={\frac{1}{\sqrt{2}\left(1+v\right)}\left[{\left({\epsilon }_x-{\epsilon }_y\right)}^2+{\left({\epsilon }_y-{\epsilon }_z\right)}^2+{\left({\epsilon }_z-{\epsilon }_x\right)}^2+\frac{3}{2}\left({\gamma }_{\mathrm{xy}}^2+{\gamma }_{\mathrm{yz}}^2+{\gamma }_{\mathrm{xz}}^2\right)\right]}^{\frac{1}{2}}$

[0753] Where epsilon_x, epsilon_y, epsilon_z are component strain values, Greek symbol _nu prime is the effective Poisson's ratio, and gamma are the corresponding shear strains. Thus, the allowable bending portion of the strain along the hub-to-blade connector 1788 will be less than 8%, and without loss of generality, after accounting for all the other geometrically-computed strain components, it may result in the maximum desired bending strain distribution along the radial length of the hub-to-blade connector 1788 shown in FIG. 200.

[0754] Thus for a given plate thickness, FIG. 200 shows maximum desired bending strain as a function of radial length along hub-blade connector 1788. Using the R=c/ε equation above, and using as local ε the value shown in FIG. 200 results in a minimum value of local radius R corresponding to maximum allowed total local bending strain, so that the combined strain does not exceed the 8% elasticity limit. Without loss of generality, this may result in the maximum allowed value of desired curvature distribution (the inverse of the local minimum radius) shown in FIGS. 201, 202A and 202B along the radial length of the hub-to-blade connector 1788. Thus, for given plate thickness 2c, this allows us to determine the allowable minimum local radius of curvature distribution of the supporting structure 1780 along its radial length, so that the bending plate, when collapsed, stays in the recoverable elastic regime.

[0755] The combination of the above leads to the conclusion that the supporting structure 1780 can become a curvature controller, where the local radius varies along it length, computed as shown in FIG. 201 in order to not exceed the allowable bending strain of FIG. 200 as described above.

[0756] The results are corroborated with FEA calculations with ANSYS as shown in FIG. 202C-202F. The dotted line in the stress-strain figure is programmed into the FEA calculations. Two hub-to-blade connector 1788 with 3D twist along their length shown in FIG. 202B are modelled. The hub-to-blade connectors 1788 are simulated to collapse as a simulated cylindrical catheter advances to fold them around the computed varying-curvature supporting structure 1780. The resultant stress strain calculations along the length of the hub-to-blade connector 1788 are computed. The maximum computed stress and strain values, located near the region of minimum bending radius of the hub-to-blade connector 1788, are about 700 MPa and 8% strain as shown in FIGS. 202D and 202E.

[0757] The procedure described above, with the use of supporting structures 1780 such as the curvature controller with varying curvature around its arc placed in key locations, can be used to control the local deformation (strain) and stress of any part of the collapsing nitinol structure to ensure it does not reach permanent deformation on collapsing.

[0758] In some embodiments, the stress-strain relation of nitinol under repeated loads is used to compute the maximum combined bending and torsional strain to remain in the elastic regime, and the corresponding maximum bending stress, so that with the use of a varying-shape structural support, the overall structure remains in the elastic regime under repeated loading and unloading. In some embodiments, the method above is used to compute the shape of a shape-controlling support for the structure to remain in elastic regime in repeated loading and unloading carrying various bending and torsional loads. In some embodiments, a shape-controlling support (curvature controller) limits local bending for device to stay in elastic regime under repeated loading and unloading under combined bending and torsional loads. In some embodiments, the shape-controlling support is computed based on shape-computation method.

[0759] In some embodiments, a mechanical circulatory support heart-assist device configured to be inserted with minimally invasive surgery is provided. The device can include a pump head. In some embodiments, the pump head comprises at least two contra-rotating non-magnetic impellers comprising blades configured to be installed in the vasculature. In some embodiments, the blades are driven by two coaxial contra-rotating motors.

[0760] In some embodiments, the contra-rotation of the two coaxial contra-rotating motors are at equal revolutions per minute. In some embodiments, the contra-rotation of the two coaxial contra-rotating motors are at unequal revolutions per minute. In some embodiments, the at least two contra-rotating non-magnetic impellers comprise an equal number of blades in the two impellers. In some embodiments, the at least two contra-rotating non-magnetic impellers comprise different number of blades in the upstream and downstream impeller. In some embodiments, the number of blades in each contra-rotating non-magnetic impellers is a prime odd number. In some embodiments, one contra-rotating non-magnetic impeller comprises an even number of blades and one contra-rotating non-magnetic impeller comprises an odd number of blades. In some embodiments, two contra-rotating non-magnetic impellers comprise an even number of blades. In some embodiments, impeller segments are azimuthally positioned with mechanical fixing arrangements, and carry torque with the mechanical fixing arrangement. In some embodiments, the motors are intra-corporeal. In some embodiments, the motors are extra-corporeal. In some embodiments, the at least two contra-rotating non-magnetic impellers are foldable against hubs for installation and removal in a blood vessel. In some embodiments, the at least two contra-rotating non-magnetic impellers comprise a diameter between 2 mm and 40 mm. In some embodiments, the at least two contra-rotating non-magnetic impellers are inside a folding hourglass-shaped frame. In some embodiments, the folding hourglass-shaped frame comprises an inlet, a waist, and a diffuser. In some embodiments, the folding hourglass-shaped frame comprises an expanded shape with a waist that fits within blood vessels having a diameter between 4 mm and 50 mm. In some embodiments, the folding hourglass-shaped frame comprises an expanded shape with an inlet and diffuser that fit within blood vessel having a diameter between 4 mm and 60 mm. In some embodiments, the at least two contra-rotating non-magnetic impellers are driven by the two coaxial contra-rotating motors via flexible contra-rotating shafts. In some embodiments, the flexible contra-rotating shafts are coated with interior or exterior high-lubricity coatings. In some embodiments, the flexible contra-rotating shafts are covered in a stationary shaft sheath. In some embodiments, the flexible contra-rotating shafts are covered in a stationary sheath. In some embodiments, the stationary sheath are coated with interior high-lubricity coatings. In some embodiments, a space between an external shaft of the flexible contra-rotating shafts and the stationary sheath is coated with interior or exterior high-lubricity coatings. In some embodiments, the flexible contra-rotating shafts and the stationary sheath are coated with interior or exterior high-lubricity coatings and flushed via biocompatible liquid. In some embodiments, a space is configured to be flushed and lubricated via biocompatible liquid. In some embodiments, components of the device are coated with interior or exterior high-lubricity coatings, biocompatible materials, anti-coagulants, or drug-eluting compounds. In some embodiments, the stationary sheath comprises a biocompatible material. In some embodiments, a catheter is located between the motors and the folding hourglass-shaped frame. In some embodiments, the blades and the folding hourglass-shaped frame are configured to be pulled by a flexible shaft inside the catheter for implantation, then inserted in the vasculature, then expanded in the vasculature for use as a blood pump. In some embodiments, the flex shafts from the motors all the way to the tip extender are fixed length, and the catheter is configured to be advanced by folding the hourglass and blades, the nose cone moves a little upstream, and the device collapses. In some embodiments, after a period of use, the blades and the folding hourglass-shaped frame are again collapsed into the catheter for removal from the vasculature. In some embodiments, the space between the flexible contra-rotating shafts or between the flexible contra-rotating shafts and a shaft sheath or between the shaft sheath and a catheter are lubricated or flushed by a biocompatible fluid. In some embodiments, the space between the flexible contra-rotating shafts or between the flexible contra-rotating shafts and a shaft sheath or between the shaft sheath and a catheter or between the catheter and a catheter introducer are lubricated or flushed by a biocompatible fluid. In some embodiments, the two coaxial contra-rotating motors are intra-corporeal just downstream of the pump head, and electrical power is delivered via and intravascular power line or transcutaneous electric conductors from an external energy supply. In some embodiments, the blades are in a collapsible hourglass shape comprising a shape-memory alloy. In some embodiments, the shape-memory alloy forms a lattice of the collapsible hourglass shape, wherein the lattice comprises segments to make the collapsed device longer. In some embodiments, the shape-memory alloy forms a lattice of the collapsible hourglass shape, wherein the lattice comprises segments parallel to the centerline of the hourglass to make the collapsed device shorter. In some embodiments, struts of a diffuser are as dense a lattice as the diffuser siding lattice. In some embodiments, portions of an hourglass frame, or the whole of the hourglass frame, is covered with a biocompatible material. In some embodiments, portions of the hourglass frame, or the whole of the hourglass frame, or the waist, or the waist and the diffuser, or the waist and diffuser and inlet, is covered with a biocompatible material. In some embodiments, the biocompatible material comprises anti-thrombotic or drug-eluting properties. In some embodiments, the biocompatible material is impervious to flow. In some embodiments, the biocompatible material is partially pervious to flow. In some embodiments, holes in a membrane are oval, rhomboid, or follow the nitinol lattice. In some embodiments, holes in a biocompatible membrane are in the inlet, or diffuser, or waist segment. In some embodiments, the biocompatible material is configured to define the maximum expansion shape of a waist of the hourglass frame. In some embodiments, the biocompatible material is configured to assist in controlling radial and axial lengths in expanded shape and in collapsed shape. In some embodiments, a waist of the hourglass frame is covered with a biocompatible material. In some embodiments, the waist of the hourglass frame, or the waist and the diffuser, is covered with a biocompatible material. In some embodiments, the biocompatible material acts as a housing to the at least two contra-rotating non-magnetic impellers. In some embodiments, a biocompatible material and a shape memory alloy form a diffuser downstream of the at least two contra-rotating non-magnetic impellers. In some embodiments, an inlet is not covered by a biocompatible material. In some embodiments, an inlet is partially covered by a biocompatible material. In some embodiments, an inlet is not covered or is partially covered by a biocompatible material to allow perfusion of intercostal and spinal arteries. In some embodiments, the device further comprises an hourglass frame, wherein the hourglass frame is made of segments joined together. In some embodiments, the hourglass frame or the segments are connected to a shaft via struts. In some embodiments, the hourglass frame or the segments are connected to a shaft via struts or any supporting structure such as struts. In some embodiments, the struts are integral with a tube. In some embodiments, the struts or any supporting structure such as struts are integral with a tube. In some embodiments, the tube is surrounded by a shaft holder. In some embodiments, a waist of the hourglass frame comprises at least one set of struts at a proximal or a distal end. In some embodiments, a waist of the hourglass frame comprises at least one set of struts or any supporting structure such as struts at a proximal or a distal end. In some embodiments, a waist of the hourglass frame comprises a set of struts at a proximal end and a set of struts at a distal end. In some embodiments, a waist of the hourglass frame comprises a set of struts or any supporting structure such as struts at a proximal end and a set of struts or any supporting structure such as struts at a distal end. In some embodiments, a diffuser of the hourglass frame comprises at least one set of struts at proximal or distal end. In some embodiments, a diffuser of the hourglass frame comprises at least one set of struts or any supporting structure such as struts at proximal or distal end. In some embodiments, the hourglass frame comprises at least one set of struts, tube, or shaft holder at proximal or distal end. In some embodiments, the hourglass frame comprises at least one set of struts or any supporting structure such as struts, tube, or shaft holder at proximal or distal end. In some embodiments, at least one set of struts, tube, or shaft holder is displaced upstream when the device collapses. In some embodiments, at least one set of struts or any supporting structure such as struts, tube, or shaft holder is displaced upstream when the device collapses. In some embodiments, at least one set of struts or any supporting structure, tube, or shaft holder is displaced downstream when the device collapses. In some embodiments, at least one set of struts or any supporting structure such as struts, tube, or shaft holder is displaced downstream when the device collapses. In some embodiments, at least one set of struts is activated to collapse the whole device for implantation. In some embodiments, at least one set of struts or any supporting structure such as struts is activated to collapse the whole device for implantation. In some embodiments, at least one set of struts is activated to collapse the hourglass for implantation. In some embodiments, at least one set of struts or any supporting structure such as struts is activated to collapse the hourglass for implantation. In some embodiments, at least one set of struts collapses the waist segment, which in turn collapses the blades for implantation. In some embodiments, at least one set of struts or any supporting structure such as struts collapses the waist segment, which in turn collapses the blades for implantation. In some embodiments, the collapsing struts, shaft holders and/or blades move upstream or downstream. In some embodiments, the collapsing struts or any supporting structure such as struts, shaft holders and/or blades move upstream or downstream. In some embodiments, the collapsed hourglass frame and blades expand in the vasculature for use as a blood pump. In some embodiments, the struts are activated to collapse the device for removal after use. In some embodiments, the struts or any supporting structure such as struts are activated to collapse the device for removal after use. In some embodiments, at least one strut is activated to collapse the hourglass frame for removal after use. In some embodiments, at least one strut or any supporting structure such as struts is activated to collapse the hourglass frame for removal after use. In some embodiments, at least one strut is activated to collapse the blades for removal after use. In some embodiments, the blades are collapsed by the radially-collapsing waist segment, which is collapsed by the radially-collapsing diffuser, which is collapsed by the diffuser strut. In some embodiments, at least one strut or any supporting structure such as struts is activated to collapse the blades for removal after use or by the radially-collapsing waist segment, which is collapsed by the radially-collapsing diffuser, which is collapsed by the diffuser strut. In some embodiments, a shaft sleeve is configured as a catheter device. In some embodiments, the blades fold upstream during recovery. In some embodiments, the blades fold downstream during recovery. In some embodiments, the impellers comprise at least two blade-carrying assemblies. In some embodiments, impeller portions or impeller segments or blade carrying assemblies are held in specific azimuthal orientations by indexing shapes and recesses. In some embodiments, the at least two blade-carrying assemblies are rotated to different azimuthal orientation around their axis or impeller segments or blade carrying assemblies are held in specific azimuthal orientations by indexing shapes and recesses. In some embodiments, the blades partially overlap. In some embodiments, the blades are made from an airfoil mounted to the hub. In some embodiments, the blades are made from a three-dimensional varying thickness airfoil mounted to the hub via a hub-blade interconnect. In some embodiments, the blades are made from an airfoil mounted to the hub or three-dimensional varying thickness airfoil mounted to the hub via a hub-blade interconnect. In some embodiments, the blades are shaped into three dimensional objects with varying blade angle from hub to tip. In some embodiments, the blades are made from flat plates and shaped into three dimensional objects with varying blade angle from hub to tip. In some embodiments, the device comprises supporting structures configured to provide shaft rigidity between shaft holders. In some embodiments, the device comprises supporting structures configured to eliminate slow flow regions near hubs. In some embodiments, the device comprises a flexible shaft connects one impeller of the at least two contra-rotating non-magnetic impellers with one motor via a core shaft rotating in one direction. In some embodiments, the core shaft is covered with biocompatible lubricious coating. In some embodiments, the device comprises a flexible shaft connects one impeller of the at least two contra-rotating non-magnetic impellers with one motor via a core shaft rotating in one direction or wherein the core shaft is covered with biocompatible lubricious coating. In some embodiments, the core shaft comprises a hollow cross section. In some embodiments, the core shaft is covered with biocompatible coating. In some embodiments, the coating is perforated or spiral or other intermittent shape. In some embodiments, the core shaft has solid cross section. In some embodiments, the core shaft is a braided wire. In some embodiments, the core shaft is flexible. In some embodiments, the other impeller of the at least two contra-rotating non-magnetic impellers is connected to the other motor via a peripheral shaft surrounding the core shaft. In some embodiments, the peripheral shaft is covered with biocompatible coating on inside, on outside, or both the inside and outside. In some embodiments, the coating is perforated or spiral or other intermittent shape. In some embodiments, the peripheral shaft is a perforated cylinder. In some embodiments, the peripheral shaft is made of one coil, wherein wire of the coil comprises a round cross-section or a rectangular cross-section. In some embodiments, the peripheral shaft comprises two contra-rotating coils. In some embodiments, the peripheral shaft is flexible. In some embodiments, the device comprises contra-rotating shafts disposed within a stationary sleeve. In some embodiments, the stationary sleeve comprises PTFE, polymer, plastic, or shape memory alloy. In some embodiments, the stationary sleeve is internally and/or externally coated with biocompatible lubricious coating. In some embodiments, the core shaft is attached to a tip extender forming the pivot point for the collapse of the device. In some embodiments, the tip extender is flexible. In some embodiments, the tip extender is covered by a stationary nose cone attached to a stationary shaft holder. In some embodiments, a portion of shafts between the first shaft holder and the second shaft holder is rigid. In some embodiments, a portion of shafts between a first shaft holder and a second shaft holder is rigid. In some embodiments, the device comprises at least one fluid path to provide flushing fluid and/or lubrication to flexible contra-rotating shafts. In some embodiments, the device comprises at least one fluid path to provide flushing fluid between a stationary shaft sleeve and a catheter. In some embodiments, the device comprises at least two fluid paths to provide flushing fluid and/or lubrication to flexible contra-rotating shafts. In some embodiments, the device comprises two or more flushing fluid paths, wherein the two or more flushing fluid and/or lubrication paths are combined to be supplied by one pressure or gravity bag. In some embodiments, the device comprises two or more of the flushing fluid and/or lubrication paths, wherein the two or more flushing fluid and/or lubricating paths are combined into one by slits or other openings between a peripheral shaft and a core shaft, between the peripheral shaft and a shaft sleeve, or between the shaft sleeve and a catheter. In some embodiments, the device comprises a polymer or similar coating between members within a flushing and/or lubricating fluid path between a peripheral shaft and a core shaft, between the peripheral shaft and a shaft sleeve, or between the shaft sleeve and a catheter. In some embodiments, the device comprises a polymer or similar coating between members within a flushing and/or lubricating fluid path between a peripheral shaft and a core shaft, between the peripheral shaft and a shaft sleeve, between the shaft sleeve and a catheter, or between the catheter and a catheter introducer. In some embodiments, the device comprises a polymer or similar coating comprises a spiral. In some embodiments, the device comprises a biocompatible membrane deposited around the perimeter as a spiral tube of biocompatible material, or it can be a weave sputtered around. In some embodiments, the two coaxial contra-rotating motors comprise two extracorporeal motors. In some embodiments, the two coaxial contra-rotating motors comprise at least one intracorporeal motor. In some embodiments, the two coaxial contra-rotating motors comprise at least one intracorporeal motor, or one intracorporeal motor, or two intracorporeal motors. In some embodiments, the two coaxial contra-rotating motors comprise one extracorporeal motor and one intracorporeal motors. In some embodiments, the device allows axial bending between the impellers for implantation via the vasculature. In some embodiments, the device comprises an impeller interconnect sleeve. In some embodiments, the device comprises an impeller interconnect flexible sleeve allowing bending of the device for percutaneous placement in the blood vessel. In some embodiments, the impeller interconnect flexible sleeve allows bending of the device for percutaneous placement in the blood vessel. In some embodiments, the impeller interconnect sleeve provides a flushing and/or lubricant path between the contra-rotating impellers. In some embodiments, the device comprises shaft holders comprising grooves. In some embodiments, the device comprises shaft holder configured to prevent blood ingress into the shaft holder. In some embodiments, the flush flow prevents blood flow into the shaft holders, the nose cone, the impeller interconnect, and between shaft sleeve and catheter, wherein the groves helping further. In some embodiments, the device comprises shaft holder configured to prevent blood ingress into the shaft holder or wherein the flush flow prevents blood flow into the shaft holders, the nose cone, the impeller interconnect, and between shaft sleeve and catheter, wherein the groves helping further. In some embodiments, the device comprises shaft holder configured to provide a flushing and/or lubrication path. In some embodiments, the blades overlap for smooth and controlled folding. In some embodiments, the impeller comprises any number of blades. In some embodiments, the blades are in two halves to accommodate overlap and the overlap accommodates smooth folding of the blades in overlapping positions. In some embodiments, the device comprises supporting struts made of lattice of the same density as the hourglass frame. In some embodiments, the device comprises supporting struts or any supporting structure such as struts made of lattice of the same density as the hourglass frame. In some embodiments, the variation between the diameter of the expanded waist, and the minimum and maximum variation of the expanded inlet and diffuser, for one-size-device fits-all blood vessels. In some embodiments, the device comprise a shaft holder comprising interior grooves and exterior grooves configured to control the flow rate and direction of flow of the flush and/or lubricant between concentric components. In some embodiments, the device comprise a shaft holder comprising interior grooves and exterior grooves configured to direct flush flow and prevent blood flow in, where parts do not need to be concentric. In some embodiments, the device comprise a shaft holder comprising interior grooves and exterior grooves configured to control the flow rate and direction of flow of the flush and/or lubricant between concentric components or configured to direct flush flow and prevent blood flow in, where parts do not need to be concentric. In some embodiments, the device comprises a slot in a peripheral shaft configured for passing flush and/or lubricant from inside the peripheral shaft into the space between peripheral shaft and a shaft holder. In some embodiments, the peripheral slots allow flow to a shaft sleeve and to a peripheral perforated tube at tip extender. In some embodiments, the device comprises a slot in a peripheral shaft configured for passing flush and/or lubricant from inside the peripheral shaft into the space between peripheral shaft and a shaft holder or wherein the peripheral slots allow flow to a shaft sleeve and to a peripheral perforated tube at tip extender. In some embodiments, grooves at the two ends of shaft holder limit the amount of flush and/or lubricant needed and impart velocity to the outgoing fluid. In some embodiments, the grooves are in several components including a nose cone and a shaft holder. In some embodiments, grooves at the two ends of shaft holder limit the amount of flush and/or lubricant needed and impart velocity to the outgoing fluid or wherein the grooves are in several components including a nose cone and a shaft holder. In some embodiments, the length of the shaft holder is at least as long as required to ensure the slot stays between the grooves when the device is installed in various sizes of blood vessels. In some embodiments, the shaft holder is further up the shaft (upstream) when the device is installed in larger diameter blood vessel, and lower down the shaft (further downstream) when the device is in smaller diameter blood vessel. In some embodiments, the tip of the nose cone comprises a curved segment at the upstream external tip to facilitate implantation through the vasculature. In some embodiments, the device comprises a diffuser, wherein the lattice of the diffuser comprises a consistent density along the length of the diffuser. In some embodiments, the lattice comprises a non-uniform lattice to allow smaller axial expansion of the collapsed device. In some embodiments, the device comprises a diffuser, wherein the lattice of the diffuser comprises a consistent density to a shaft holder. In some embodiments, the device is configured to allow perfusion between the outer diameter of the device and the inner diameter of the blood vessel, thus allowing for perfusion of blood vessels in between, with particular reference to not covering the intercostal arteries and especially the spinal artery during operation. In some embodiments, the diffuser is covered to improve the fluid dynamics. In some embodiments, the device comprises a covering of material comprising openings anywhere on the material and having any shape. In some embodiments, the material comprises antithrombotic and/or anticoagulant and/or drug-eluting coating. In some embodiments, a supporting structure is placed to limit the combination of bending and torsion stresses and strains, so the collapsed structure remains in the elastic regime. In some embodiments, the bending direction of collapsed components is mechanically secured to fall between the rolling direction of shape-memory alloy sheets and the direction perpendicular to the rolling direction, to even out deformations, stresses, and local forces during collapsing and expanding.

[0761] Although the present invention has been described in terms of certain preferred embodiments, it may be incorporated into other embodiments by persons of skill in the art in view of the disclosure herein. The scope of the invention is therefore not intended to be limited by the specific embodiments disclosed herein, but is intended to be defined by the full scope of the following claims. It is understood that this disclosure, in many respects, is only illustrative of the numerous alternative device embodiments of the present invention. Changes may be made in the details, particularly in matters of shape, size, material and arrangement of various device components without exceeding the scope of the various embodiments of the invention. Those skilled in the art will appreciate that the exemplary embodiments and descriptions thereof are merely illustrative of the invention as a whole. While several principles of the invention are made clear in the exemplary embodiments described above, those skilled in the art will appreciate that modifications of the structure, arrangement, proportions, elements, materials and methods of use, may be utilized in the practice of the invention, and otherwise, which are particularly adapted to specific environments and operative requirements without departing from the scope of the invention. In addition, while certain features and elements have been described in connection with particular embodiments, those skilled in the art will appreciate that those features and elements can be combined with the other embodiments disclosed herein.

[0762] When a feature or element is herein referred to as being “on” another feature or element, it can be directly on the other feature or element or intervening features and/or elements may also be present. In contrast, when a feature or element is referred to as being “directly on” another feature or element, there are no intervening features or elements present. It will also be understood that when a feature or element is referred to as being “connected”, “attached” or “coupled” to another feature or element, it can be directly connected, attached or coupled to the other feature or element or intervening features or elements may be present. In contrast, when a feature or element is referred to as being “directly connected”, “directly attached” or “directly coupled” to another feature or element, there are no intervening features or elements present. Although described or shown with respect to one embodiment, the features and elements so described or shown can apply to other embodiments. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature.

[0763] Terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. For example, as used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items and may be abbreviated as “/”.

[0764] Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus, the exemplary term “under” can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms “upwardly”, “downwardly”, “vertical”, “horizontal” and the like are used herein for the purpose of explanation only unless specifically indicated otherwise.

[0765] Although the terms “first” and “second” may be used herein to describe various features/elements (including steps), these features/elements should not be limited by these terms, unless the context indicates otherwise. These terms may be used to distinguish one feature/element from another feature/element. Thus, a first feature/element discussed below could be termed a second feature/element, and similarly, a second feature/element discussed below could be termed a first feature/element without departing from the teachings of the present invention.

[0766] Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising” means various components can be co-jointly employed in the methods and articles (e.g., compositions and apparatuses including device and methods). For example, the term “comprising” will be understood to imply the inclusion of any stated elements or steps but not the exclusion of any other elements or steps.

[0767] As used herein in the specification and claims, including as used in the examples and unless otherwise expressly specified, all numbers may be read as if prefaced by the word “about” or “approximately,” even if the term does not expressly appear. The phrase “about” or “approximately” may be used when describing magnitude and/or position to indicate that the value and/or position described is within a reasonable expected range of values and/or positions. For example, a numeric value may have a value that is +/−0.1% of the stated value (or range of values), +/−1% of the stated value (or range of values), +/−2% of the stated value (or range of values), +/−5% of the stated value (or range of values), +/−10% of the stated value (or range of values), etc. Any numerical values given herein should also be understood to include about or approximately that value, unless the context indicates otherwise. For example, if the value “10” is disclosed, then “about 10” is also disclosed. Any numerical range recited herein is intended to include all sub-ranges subsumed therein. It is also understood that when a value is disclosed that “less than or equal to” the value, “greater than or equal to the value” and possible ranges between values are also disclosed, as appropriately understood by the skilled artisan. For example, if the value “X” is disclosed the “less than or equal to X” as well as “greater than or equal to X” (e.g., where X is a numerical value) is also disclosed. It is also understood that the throughout the application, data is provided in a number of different formats, and that this data, represents endpoints and starting points, and ranges for any combination of the data points. For example, if a particular data point “10” and a particular data point “15” are disclosed, it is understood that greater than, greater than or equal to, less than, less than or equal to, and equal to 10 and 15 are considered disclosed as well as between 10 and 15. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.

[0768] The examples and illustrations included herein show, by way of illustration and not of limitation, specific embodiments in which the subject matter may be practiced. As mentioned, other embodiments may be utilized and derived there from, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. Such embodiments of the inventive subject matter may be referred to herein individually or collectively by the term “invention” merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept, if more than one is, in fact, disclosed. Thus, although specific embodiments have been illustrated and described herein, any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description. The claims below are representative claims, and may be restructured and combined with other features described in the embodiments herein.