Circulatory assist pump
11602627 · 2023-03-14
Assignee
Inventors
Cpc classification
A61M60/139
HUMAN NECESSITIES
A61M60/237
HUMAN NECESSITIES
A61M60/825
HUMAN NECESSITIES
A61M60/13
HUMAN NECESSITIES
A61M60/562
HUMAN NECESSITIES
A61M60/216
HUMAN NECESSITIES
A61M60/523
HUMAN NECESSITIES
A61M2205/8262
HUMAN NECESSITIES
A61M60/808
HUMAN NECESSITIES
A61M60/422
HUMAN NECESSITIES
A61M60/873
HUMAN NECESSITIES
A61M60/414
HUMAN NECESSITIES
A61M60/148
HUMAN NECESSITIES
International classification
A61M60/139
HUMAN NECESSITIES
A61M60/148
HUMAN NECESSITIES
A61M60/562
HUMAN NECESSITIES
A61M60/873
HUMAN NECESSITIES
A61M60/808
HUMAN NECESSITIES
A61M60/216
HUMAN NECESSITIES
A61M60/13
HUMAN NECESSITIES
Abstract
A minimally invasive circulatory support platform that utilizes an aortic stent pump or pumps. The platform uses a low profile catheter-based techniques and provides temporary and chronic circulatory support depending on the needs of the patient. Also described is a catheter-based temporary assist pump to treat patients with acute decompensated heart failure and provide circulatory support to subjects undergoing high risk percutaneous coronary intervention (“PCI”). Further described is a wirelessly powered circulatory assist pump for providing chronic circulatory support for heart failure patients. The platform and system are relatively easy to place, have higher flow rates than existing systems, and provide improvements in the patient's renal function.
Claims
1. A system for a circulatory assist pump, which system maintains arterial pulsatility, the system comprising: a circulatory assist pump, comprising: a distal tip; and a proximal end opposite the distal tip, the proximal end removably connectable to a catheter; and an impeller system between and connected to the distal tip and the proximal end, the impeller system including pivotally mounted arm-like impeller blades, which are foldable and retractable, which arm-like impeller blades, during operation rotate to draw blood down a subject's aorta from the subject's heart; and a stent cage encaging the circulatory assist pump, the stent cage comprising wire-like elements having ends secured to the distal tip and the proximal end of the circulatory assist pump, wherein the stent cage expands and compresses and is of a size and shape to allow a highly open flow of blood therethrough when placed within the subject's aorta, and further having an expanded circumference sized to be stable against the subject's aortic wall wherein the wire-like elements of the stent cage distend the subject's aortic wall to positionally affix the stent cage to the subject's aorta during operation of the impeller system while allowing the subject's aorta to maintain its natural pulsatility; wherein, when the system is positioned and operated in the aorta proximal and above the renal arteries of the subject, natural aortic wall pulsatility is maintained.
2. A method of treating a subject suffering from heart disease, the method comprising: implanting the system of claim 1 into the subject and utilizing the impeller system of arm-like impeller blades to draw blood down the aorta from the subject's heart.
3. The method according to claim 2, wherein the system is controllable wirelessly.
4. The method according to claim 3, wherein the wireless control controls pulsatility, speed, and/or impeller angle of the system.
5. The method according to claim 2, wherein, after implantation, the impeller rotates at less than 10,000 RPM.
6. The method according to claim 5, wherein, in operation, the impeller rotates on the order of 4,500 RPM to achieve 4.5 liters flow at the level of the subject's renal arteries.
7. The method according to claim 2, wherein the impeller system is powered wirelessly.
8. A method of treating a subject suffering from heart disease, the method comprising: utilizing the system of claim 1 to treat the subject.
9. The method according to claim 8, further comprising: implanting at least one sensor into the subject.
10. The method according to claim 9, wherein the sensor(s) monitor(s) fluid flow in the aorta and provides feedback and data to the system, and wherein the feedback and data are used to adjust the speed and/or angle of the arm-like impeller blades in the subject's aorta and/or to increase or decrease fluid flow and pressure in the subject's aorta.
11. The method according to claim 8, further comprising: promoting protein expression and or release within the subject's aorta.
12. The method according to claim 8, further comprising: utilizing vibrating harmonic resonance to reduce blood clots in the subject.
13. The system of claim 1, wherein the system is controllable wirelessly.
14. The system of claim 13, wherein the wireless control controls pulsatility, speed, and/or impeller angle of the system.
15. The system of claim 13, further comprising: an external belt, for placement about the subject, for controlling and/or powering the system.
16. The system of claim 1, further comprising a drive shaft for the impeller system.
17. The system of claim 16, wherein the impeller system has an ePTFE liner.
18. The system of claim 1, wherein the circulatory assist pump comprises a cam that extends and withdraws the arm-like impeller blades into and out of a catheter associated with the cam.
19. The system of claim 1, further comprising a pulsating cuff for placement upstream the stent cage in the aorta.
20. The system of claim 1, wherein the impeller system is powered wirelessly.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
(17) An aspect of the disclosure is a circulatory assist pump, generally 10, shown in
(18) The depicted circulatory assist pump includes a positioning cable 18 running along the impeller axis, about which the impeller blades 14, 16 (along with the rest of the device) rotate to create a pump action, for example, in the aorta. The arm-like nature of the depicted blades allows them to extend maximally from the remainder of the body when in a perpendicular position and fill a large portion of the descending aorta. At the end of the positioning cable is a rod 20 that interacts with a cam portion 22 of each impeller blade (see, e.g.,
(19) As depicted in
(20) In certain embodiments, the impeller blades can be tilted on demand (in the same manner as the way an airplane wing flaps are controlled) by, e.g., adjustment of the cams, which balances hemolysis, thrust, and flow; maximizes flow with a temporary increase in hemolysis; and can be used to catch native aortic flow to re-charge a battery in the center spindle.
(21) An aortic stent cage surrounds the impeller (see, e.g.,
(22) Prior art devices have been known to migrate up and down and bounce side to side in the aorta. Their flow is disturbed and energy is lost in the process. Their movement causes turbulence, which promotes blood clotting and hemolysis.
(23) An aortic stent as described herein (see, e.g.,
(24) The system is preferably positioned and stabilized in the aorta and the available impeller space is widened with a high radial force aortic stent that distends the aortic wall inner diameter, for example, about two (2) mm. Such positioning allows more flow and more use of the entire area of the aorta, particularly in comparison to the prior art. Such aortic stent strength stabilizes position and reduces the need for repositioning.
(25) In preferred embodiments, a confirming high radial force aortic stent provides for firm stability of fixation of position without the need for hooks. Such a system distends the diameter of the aorta by about two (2) mm (on average), which provides more space available for impeller use.
(26) The expandable stent may be manufactured and adapted for use herein in accordance with techniques known by those of skill in the art (see, e.g., U.S. Pat. No. 5,354,308 to Simon et al. (Oct. 11, 1994), U.S. Pat. No. 4,580,568 to Cesare Gianturco (Apr. 8, 1986), and U.S. Pat. No. 5,957,949 to Leonhardt et al. (Sep. 28, 1999), the contents of each of which are incorporated herein by this reference).
(27) Depicted is a circulatory assist pump within a bare aortic stent at the tip of a 13.8 French (“FR”) catheter for temporary support. The aortic stent with impeller (e.g.,
(28) In certain embodiments, the catheter protective cage aortic stent expands and compresses easily, e.g., to pass another catheter by the stent cage. For example, a standard PCI catheter was run up the outside of the stent cage and was of no issue. The radial force of the stent is insufficient to collapse the PCI catheter, particularly when placed against a compliant aorta. The stent typically presses the PCI catheter about 1 mm into the aorta wall and leaves open the whole aorta for the impeller with a large safety gap. The impeller may be angled down like arrow feathers, and then there is even more room for placing a PCI catheter.
(29) The protective cage opens and closes relatively easily with a simple turn of the wheel on a handle associated with the catheter (
(30) As best depicted in
(31) In certain embodiments (e.g., to reduce the chance that the impeller impacts the stent cage on the side where the PCI catheter is present), the impeller is not extended all of the way (e.g., instead of opening it 11.5 mm wide in a 22 mm aorta, it is only opened, e.g., 8 mm wide, but it still provides 80 to 90% of the flow as compared to when the impeller blades are fully open).
(32) In certain embodiments, the impeller is first started turning with the blades, e.g., only half way open, and after it has been confirmed (e.g., either by measuring flow, viewing the situation, or otherwise) that sufficient gap space exists in the aorta, then the impeller is, e.g., fully opened. This serves to allow one to pump in smaller aortas. A half open impeller diameter is only about 8 mm, while fully open may be, e.g., 11.5 to 18 mm depending on size. Only about 20% of the flow is lost at “half open” in comparison to full open. In some test cases, the flow at “half open” was equal to the flow at full open in animal studies at Tufts Medical Center.
(33) In certain embodiments, magnetized impeller blade tips may be powered wirelessly by an external power belt (electrically powered with a copper coil inside) place around, e.g., the patient's abdomen. Wireless power enables the system to provide the patient with a better quality of life, while reducing the risk of infections and providing the physician with greater patient management options. Wireless power systems are disclosed in, e.g., J. Bowler “This Wireless Heart Pump Battery Could Save Thousands of Lives” ScienceAlert (May 26, 2017) and Knecht et al., “High Efficiency Transcutaneous Energy Transfer for Implantable Mechanical Heart Support Systems” (November 2015); DOI: 10.1109/TPEL.2015.2396194, the contents of each of which are incorporated herein by this reference. Such a transcutaneous energy transfer system (“TETS”) may be used, e.g., with a ventricular assist device. A TETS system setup includes a power converter, rectifier, and coils. See, also, Ho et al. “Midfield Wireless Powering for Implantable Systems,” Proceedings of the IEEE, pp. 1-10 (2013 IEEE), the contents of which are also incorporated herein by this reference.
(34) In certain embodiments, WiFi power may be used to control and power the device/system (with WiFi power) instead of using a belt. In such embodiments, repeater, booster, and/or extender technology, may be used with an external wireless power belt to reduce irritation and heating of, e.g., the subject's skin. See, e.g., “WiFi Boosters, Repeaters and Extenders” RepeaterStore, (https://www.repeaterstore.com/pages/wifi-booster-repeater-extender-differences) (accessed Feb. 26, 2018), the contents of which are incorporated herein by this reference. The system preferably utilizes wireless repeater power with minimal skin irritation. See, also, D. Gershgorn “Your Wireless Internet Could Power Your Future Devices” Popular Science, (https://www.popsci.com/your-wireless-internet-could-power-your-future-devices) (Jun. 3, 2015) and J. Langston “Popular Science names ‘Power Over Wi-Fi’ one of the year's game-changing technologies,” UW News, (http://www.washington.edu/news/2015/11/18/popular-science-names-power-over-wi-fi-one-of-the-years-game-changing-technologies/) (Nov. 18, 2015), the contents of each of which are incorporated herein by this reference.
(35) Wireless control of the system can also be used to promote expression of desirable protein(s) via, e.g., implanted micro coils on the stent. See, e.g., US Patent publication US 2017/0266371 A1 to Leonhardt et al. (Sep. 21, 2017), the contents of which are incorporated herein by this reference, for protein expression signals. These micro coils too can utilize wireless energy. Wireless control can extend to pulsatility, speed, and/or impeller angle of the various components of the system. The micro coils can be utilized to control release and/or expression of protein(s) in the aorta, including the release and/or expression of elastin to improve the elasticity of the aorta and mediate stem cell homing and the release and/or expression of follistatin to build new, strong, thick smooth muscle.
(36) The pump may be placed, for example, above the renal arteries in the aorta to aid in kidney function. More flow into the kidneys means more rapid removal of excess fluids, which leads to better revival of kidney function. In certain embodiments, the system preferably uses the full diameter of the aorta to increase pump stability and reduce pump migration.
(37) In animal studies using the described system in sheep and swine, 1.5 to 2.0 liters of true augmented blood (beyond native cardiac output) were provided. With direct flow cannulas placed into the kidneys, the system able to augment renal blood flow by 25 to 50%. The pump was able to generate a gradient of more than 10 mm to unload the left ventricle and achieve improved hemodynamics without any clinically significant steal (reversed flow in the artery). Further, there was a reduced cardiac work index. There was also a significant increase in urine output and no significant hemolysis.
(38) Indications for use of the described system include cardio-renal syndrome, protecting renal function during PCI, and chronic heart failure.
(39) The outwardly foldable impeller uses rotational motion to draw blood in and down from the heart, and moves the blood down the aorta while itself remaining stationary due to the positioning of the cage stent within the aorta. In certain embodiments, controls (e.g., wireless controls) are utilized to modify the rotating impeller blade angles in order to, for example, change flow characteristics. This can be used, e.g., in short durations to dramatically increase flow at the expense of temporary increase of hemolysis, but the system can revert back to a low hemolysis angle shortly thereafter.
(40) The impeller maximizes blood flow, while minimizing hemolysis, power needs, RPMs, and turbulence. The system preferably uses the least RPMs and highest flow and thus lowest hemolysis. The use of a simple impeller lowers the risk of mechanical failure.
(41) Wireless technology can also be used to re-charge a battery or back up a battery for the system as needed.
(42) In one embodiment (not shown), a battery backup power source is housed in the center spindle of the circulatory assist pump, which battery backup power source can be charged either by impeller blade turns or by wireless external recharging.
(43) In certain embodiments, wireless power also powers the turns of the magnetized impeller blades directly, and battery power is only used as a backup.
(44) In certain embodiments, the system includes implanted sensors that assist with a real time, automatic adjustment and management of the circulatory assist support system based upon data provided by the implanted (preferably wireless) sensors. The sensors monitor fluid flow and provide feedback and data to the system, which feedback and data is used to, e.g., adjust the speed and/or angle of the impeller to increase or decrease fluid flow and pressure.
(45) Sensor(s) monitor hemolysis levels and automatically adjust the balance of RPM speed of the impellers and the pulsations of the cuffs (if present), to balance the minimization of hemolysis with the maximization of flow efficiency.
(46) In certain embodiments, the system includes means for synchronous pumping, which is determined by the sensors. See, e.g., Gohean et al. “Preservation Of Native Aortic Valve Flow And Full Hemodynamic Support With The TORVAD™ Using A Computational Model Of The Cardiovascular System,” ASAIO J. 2015 May-June; 61(3): 259-265; doi: 10.1097/MAT.0000000000000190, the contents of which are incorporated herein by this reference.
(47) The range of blood flow parameters in the ascending aorta that can result from various angulations of outflow graft anastomosis of a left ventricular assist device (“LVAD”) to the aortic wall, have been quantified as a means to understanding the mechanism of aortic valve insufficiency. See, e.g., Callington et al. “Computational fluid dynamic study of hemodynamic effects on aortic root blood flow of systematically varied left ventricular assist device graft anastomosis design,” J. Thorac Cardiovasc Surg. 2015 September; 150(3):696-704. doi: 10.1016/j.jtcvs.2015.05.034. Epub 2015 May 15, the contents of which are incorporated herein by this reference.
(48) Thus provided is the automatic adjustment of the impeller speed and pulsations of the pulsating cuff based upon real time pressure differentials and other data from the implanted sensors, which are placed in strategic positions. In a preferred embodiment, the sensors are placed above and below the catheter, cuffs, or stents. Such an embodiment optimizes flow by also timing pulsations of the pulsating cuff and impeller speed/angle with patient conditions and needs, including synchronization thereof with optimal real time pulsatile flow.
(49) With various prior art devices, clinicians need to make manual adjustments of up to a dozen times an hour around the clock to be able to manage circulatory assist support based upon a chosen constant aortic pressure differential range or other sensing parameters. In contrast, the described system can be managed automatically and more frequently with the intention of improving patient outcomes. Furthermore, in designing a wireless power-based system and taking into consideration the risk of mechanical breakdown, demands on the system can be reduced (when patient conditions permit) for a time, allowing the device to “cool off” or “rest.” Inversely, the circulatory assist support can be turned up when demands dictate a genuine need and not before.
(50) Such a system permits patient treatment to be customized on a real time personalized basis to provide superior outcomes for patients (e.g., those suffering from cardio-renal dysfunction in the advanced stages of heart failure).
(51) In one embodiment of the system, a first impeller stent pump is positioned in the subject's ascending thoracic aorta, which unloads blood from the subject's heart (e.g., the first impeller stent pump is positioned to withdraw blood from the subject's left ventricle). In such an embodiment, a pulsating, partially ePTFE (expanded polytetrafluoroethylene) covered stent graft with three (3) pulsating bands is preferably positioned in the aorta downstream from the positioned first impeller stent pump. Also, a second impeller stent pump is positioned further downstream in the subject's descending aorta, just above the subject's renal arteries.
(52) Such a three (3) band pulsating aortic stent graft typically a stent made of flexible compliant material (like an intra-aortic balloon pump (“IABP”) catheter balloon turned inside out). Two of the bands are always firmly against the aorta wall and only one band squeezes inward into the aorta at a time.
(53) Left ventricular unloading is known and described, e.g., in Watanabe et al. “Left Ventricular Unloading Using an Impella CP Improves Coronary Flow and Infarct Zone Perfusion in Ischemic Heart Failure,” J Am Heart Assoc. 2018; 7:e006462. DOI: 10.1161/JAHA.117.006462, Esposito et al. “Left Ventricular Unloading Before Reperfusion Promotes Functional Recovery After Acute Myocardial Infarction” Journal of the American College of Cardiology, Vol. 72, issue 5, pp. 501-514 (Jul. 31, 2018), Saku et al. “Total Mechanical Unloading Minimizes Metabolic Demand of Left Ventricle and Dramatically Reduces Infarct Size in Myocardial Infarction,” https://doi.org/10.1371/journal.pone.0152911 (2016), Kapur et al. “Mechanically Unloading the Left Ventricle Before Coronary Reperfusion Reduces Left Ventricular Wall Stress and Myocardial Infarct Size,” Circulation. 128. 10.1161/CIRCULATIONAHA.112.000029. (June 2013), http://dx.doi.org/10.1161/CIRCULATIONAHA. 112.000029, and “Acute Cardiac Unloading and Recovery,” Interventional Cardiology Review 2017; 12(2 Suppl 2):1-28. See, also, Esposito M L, Kapur N K. “Acute mechanical circulatory support for cardiogenic shock: the ‘door to support’ time,” F1000Research. 2017; 6:737. doi:10.12688/f1000research.11150.1.
(54) The real time auto adjustment technology should serve patients, such as those that have physiologic hemodynamic changes due to things as simple as sleep and exercise with advanced heart failure changes in edema levels and modulation of the pump thrust, volume and impeller speed may serve these patients well. By enabling real time automatic adjustments of circulatory assist pump controls to adjust to the constant turbulent changes in hemodynamic and edema conditions that occur on an ongoing basis in, e.g., advanced heart failure patients.
(55) A preferred aortic stent cage (
(56) The wire diameter of the stent cage circulatory assist catheter should be from about 0.015 to about 0.022 inches; preferably about 0.018 inches. Such a diameter is not too thin to cut blood cells and not too thick to ram them hard damaging them.
(57) The catheter and drive shaft are designed to reduce risk of mechanical breakdown by having fewer bearings, which requires less fluid lubrication and flush. They are also designed to ease placement and minimize FR size. The drive shaft lubrication system preferably has minimal bearings and utilizes liquid cooling and an expanded polytetrafluoroethylene (“ePTFE”) liner. ePTFE is commercially available from, e.g., W. L. Gore & Associates.
(58) Preferably, the impeller rotates at a number of revolutions, which is less than 10,000 rpm, preferably on the order of 4,500 rpm. Lower RPMs reduce the risk of mechanical failure and also reduce power needs. This can be important since, as reported by Kormos et al. “Left Ventricular Assist Device Malfunctions: It's More Than Just The Pump,” CIRCULATIONAHA.117.027360, originally published Jul. 3, 2017 (doi.org/10.1161/CIRCULATIONAHA.117.027360), 19% of patients suffered battery failure with the Heartmate II over 3 years. Heartmate II (Thoratec Corporation) is a heart pump called a left ventricular assist device (LVAD), which was designed to assist the left side of the heart to pump the blood a body needs. Furthermore, 21% of the HeartMate II patients were reported to have had driveline failure with the HeartMate II. The herein described preferred device having liquid cooled, minimal bearing system with ePTFE line and hydrophilic coated drive shaft act to reduce driveline failures.
(59) As depicted in
(60) A preferred handle (
(61) A preferred motor is not contained within the patient's circulation (
(62) In
(63) Such a system can generally involve two different embodiments. First, the temporary circulatory assist support pump(s) is/are placed on the tip of endovascular aortic catheter. Second, the system may include a removable chronic wireless powered implant circulatory assist pump within an aortic stent.
(64) Such a system is designed to reduce heart work load and improve perfusion, improve renal function, normal the hemodynamics of acute decompensating heart failure patients, support heart regeneration procedures, help patients recover from cardiogenic shock, reduce risks associated with percutaneous catheterization interventions (“High Risk PCI”), help patients on the amputation list. Such a system is designed to reduce end diastolic pressure and to reduce end diastolic volume. It is further designed to reduce oxygen demand of myocardium.
(65) Such a system utilizes a relatively straightforward aorta position insertion and is relatively stable over time. It promptly provides hemodynamic support. It is designed to minimize heart valve damage and to minimize coronary re-perfusion injury. It is designed to have low shear stress on blood, and minimize hemolysis.
(66) The wireless power embodiment is designed to reduce infection risk compared to external drive line systems. Also, the wireless power option helps improve the patient's quality of life.
(67) Preferably, the system is utilized with an upper aorta pulsating aortic cuff stent graft (
(68) Pulsating electromagnetic waves may be, e.g., delivered non-invasively from an abdominal belt (e.g.,
(69) In certain embodiments, the wirelessly driven impeller is contained within a high aortic force protective cage stent (
(70) The system preferably combines the upper aorta pulsating aortic stent graft with a lower aorta impeller pump within a bare aortic stent to optimize flow with the least power and the least RPMs. Other pulsating aortic stent grafts are on the outside of the aorta, while the described is preferably on the inside. This is more effective, with less variability
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(72) In certain embodiments, the belt, which is to be worn by the patient (see, e.g.,
(73) The removable pulsatile cuff stent may be placed just above the lower impeller aortic stent, which achieves approximately 2 liters per minute flow improvement on its own. The removable pulsatile cuff stent can be designed to push blood up and down or just down by programming the pulsatile elements. The removable pulsatile cuff stent is timed to pulse squeeze in optimization with the heart natural pulsatility. When the pulsatile cuff stent is in place pulsating, the impeller RPM may be reduced to 1,500 RPM to reach 4.5 liters per minute flow (estimated). This cuff placement provides the option for pulsatile flow circulatory assist augmentation.
(74) Pulsatile stent grafts (see, e.g.,
(75) In one embodiment, a pulsatile stent graft may be included within the system, placed mid-aorta, while substantially continuous impeller power is applied in the bare aortic stent in the lower aorta.
(76) Preferred such systems for use herein are described in: Pahlevan and Gharib “A wave dynamics criterion for optimization of mammalian cardiovascular system,” J. Biomech. 2014 May 7; 47(7):1727-32. doi: 10.1016/j.jbiomech.2014.02.014. Epub 2014 Feb. 20., Pahlevan and Gharib “A Bio-Inspired Approach for the Reduction of Left Ventricular Workload,” PLOSone, (Jan. 24, 2014); https://doi.org/10.1371/journal.pone.0087122, Pahlevan and Gharib “Aortic Wave Dynamics and Its Influence on Left Ventricular Workload,” PLOSone, (Aug. 11, 2011); https://doi.org/10.1371/journal.pone.0023106, U.S. Pat. No. 9,125,655 to Gharib et al. (Sep. 8, 2015) for Correction and Optimization of Wave Reflection in Blood Vessels; U.S. Pat. No. 7,998,190 to Gharib et al. (Aug. 16, 2011) for Intravascular Miniature Stent Pump; U.S. Pat. No. 7,163,385 to Gharib et al. (Jan. 16, 2007) for Hydroimpedance Pump; U.S. Pat. No. 8,092,365 to Rinderknecht et al. (Jan. 10, 2012) for Resonant Multilayer Impedance Pump; U.S. Pat. No. 7,883,325 to Kheradvar et al. (Feb. 8, 2011) for Helically Actuated Positive-Displacement Pump and Method and U.S. Pat. No. 9,125,655 B2 to Phalevan, the contents of each of which are incorporated herein by this reference.
(77) Preferably, the pulsating cuff pump is positioned in the upper aorta of the subject above the stent cage impeller, which is positioned lower in the aorta. Preferably, two aortic stents in series in the aorta, the top aortic stent being fully pulsatile and the bottom aortic stent semi-pulsatile (meaning it turns, but it turns so far away from heart that it does not take away pulsaltility, it just accelerates it). This relative positioning of the two pumps maximizes flow while minimizing impeller RPM. The combination of the pulsating cuff aortic stent graft in the upper aorta with the impeller pump/aortic stent in the lower aorta reduces RPMs from, e.g., 4,500 rpm to attain 4.5 liters per minute flow to 1,500 rpm, and provides advantages in terms of hemodynamics, expression of protein(s), and flow not found in either device alone. Less RPMs requires less power, which translates to a system that is easier to power wirelessly. There is also less of a risk of a mechanical breakdown, and less resulting damage to blood cells from hemolysis.
(78) Such a system, may be combined with, e.g., a vibrating harmonic resonant device to reduce and hopefully prevent blood clots, which is “the Achilles' heel” of chronic implants. A harmonic resonant vibration system to reduce blood clots in such a system is described in U.S. Provisional Patent Application No. 62/577,395, filed Oct. 26, 2017, to Leonhardt et al. for “Harmonic Vibration Device to Prevent Blood Clot, Calcification and/or Plaque Formation on Blood Contact Surfaces,” the contents of which are incorporated herein by this reference. The system may also (or alternatively) utilize an electric charge surface treatment of the implant to further reduce risk of blood clots, calcification, and plaque forming on the device.
(79) In certain embodiments, the system includes a bi-layer magnetic fluid graft that further increases flow without hemolysis (e.g., the system utilizes a magnetic fluid-filled silicon (bi-layer) graft liner placed on the inside of the impeller stent) where the pulsaging wave augment aortic flow).
(80) In certain embodiments, the system magnetically “grabs” blood via iron particles in blood and manages flow wave pulses to optimization and flow optimization timing, which further enhances flow without increasing hemolysis. For example, pulsed electromagnetic waves cam be utilized to “grab” the iron in the patient's blood and move it in waves via an external belt.
(81) The system can further include bioelectric coils on the stent to control expression and/or release of protein(s) such as those that build strength of aortic muscle and/or aid in kidney recovery. See, e.g., the earlier incorporated US Patent publication US 2017/0266371 A1 to Leonhardt et al. (Sep. 21, 2017) and/or Macfelda et al. “Bioelectrical signals improve cardiac function and modify gene expression of extracellular matrix components” ESC Heart Failure 2017; 4: 291-300 (published online 30 Jun. 2017); DOI: 10.1002/ehf2.12169, the contents of which are incorporated herein by this reference. Via the system, inflammation and blood pressure can be managed with bioelectric signal protein expressions and membrane potential management. The platform can also be used to aid in the creation and control of smooth muscle formation in the aorta.
(82) In certain embodiments, wireless powered and programmed micro coils are utilized with the system to control aortic tissue protein expressions and to increase smooth muscle mass and to control pulsations of natural aortic muscle, a cellular muscle-based “second heart.” For example, pacing the timed electrical pulse signals may be utilized to trigger contractions of smooth muscle so to make the natural aorta a beating “second heart” optimized with native pulsatile flow.
(83) The wireless powered and programmed micro coils can be further used to control chronic inflammation and blood pressure with real time reads and adjustments.
(84) The system itself preferably utilizes programmed, real-time optimization to manage flow, hemolysis, power, and patient hemodynamics real time. The programming can be configured to change parameters, e.g., with the subject's exercise, sleep, heart failure conditions, etc., including monitoring fluid level in the patient's lungs, etc.
(85) In certain embodiments, the system includes vibrational harmonic resonant tuned technology, which reduces risk of thrombosis (blood clot formations), reduces risk of plaque or calcification formations, increases gas exchanges in aorta, and promotes healthy protein release in aorta. It is relatively easily mounted into the same belt providing wireless power and controlling pulsating implants and micro coils. Including micro coils controls protein expression in the aorta to, e.g., increase elasticity, control blood pressure, improve organ health, and control inflammation
(86) Blood clots have been the “Achilles heel” of many other chronic implant devices. Resonant harmonic vibrational energy technology may be utilized to reduce the risk of this problem. Tuned harmonic resonant vibration may be used to prevent blood clot formation at high risk stagnation points on the device. The harmonic resonance for each high risk stagnation point may be individually customized and stored in a microprocessor. The vibrational energy may be delivered in pulses in a loop hitting each high risk location of the device to prevent a large accumulation of a blood clot, which might develop.
(87) Pulsatility results in healthier hemodynamics, less risk of thrombosis, together with cellular arterial wall protein expression for superior organ recovery and patient well-being. The device described herein combines the best of pulsatile flow with continuous flow. Using pulsatile and continuous flow optimizes hemodynamics and lessens the risk of thrombosis.
(88) In certain embodiments, the system utilizes a motor console for precision performance and low vibration, with flushing built in.
(89) In certain embodiments, BION micro coil implants are incorporated into the system. They may be utilized to release proteins for the heart, aorta, arteries, lungs and kidney health. They also be utilized to provide real time data on performance, flow, pressures etc.
(90) The system can be utilized variously. For instance, as a temporary catheter alone for 6 to 72 hours. As a temporary catheter with removable pulsating cuff stent in series with both removed after use of 6 to 72 hours. The temporary use catheter may be removed, but the pulsating cuff stent may be left in place for chronic long term use. The catheter and drive shaft can be disconnected from the impeller stent, which can then be switched to wireless power on a standalone basis.
(91) In certain embodiments, there are two aortic stent based circulatory assist pumps in series in the aorta, one upper and one lower, the upper one being pulsatile.
(92) In certain embodiments, the impeller stent can be left out/removed, and the pulsating aortic cuff stent left in place.
(93) The device may be removed should the need for the device abate (e.g., upon recovery of the patient). For removing the device, a modified Seldinger technique (or comparable technique) can be applied in reverse utilizing a catheter that interacts with, e.g., the pump for removal. The impeller blades may first be retracted and the stent cage then collapsed about it to reduce the cross-sectional diameter of the pump to aid in removal.
(94) The foregoing can be supported with a vibrational harmonic resonance technology for preventing blood clot formations (thrombosis), but this is especially preferred when the system is used for chronic implant use. Furthermore, the foregoing can be supported with the release of bioelectrically controlled release of protein(s) from, e.g., the aorta, tissues, and arteries to assist in healing. Further, the foregoing can be supported by electromagnetic wave or sound wave pulsations to further enhance blood flow improvement.
(95) Although it is an advantage of the device to not need to cross the aortic valve, in certain embodiments, the described encaged pump system may be combined advantageously with a device that does cross the aortic valve (e.g., in high head/low flow applications). Such a system includes placement of the device that does cross the aortic valve at the tip of the catheter, beyond the aortic valve and placement of the herein described second device encaged impeller (bare aortic stent and pump on the catheter) proximal the renal arteries that feed the kidneys. The first such pump may be a second of the herein described pumps or a pump akin to the HeartMate PHP percutaneous heart pump. The second such pump may be that of
(96) In such a situation, sometimes the required operating conditions for a patient are beyond the reach of a single, standard pump, and it is best to combine simple pump performances that add up to the necessary requirements. Positioning pumps in series as described herein, or connected along a single line, allows the system to add the head from each pump together to meet the high head, low flow system requirements. This is because the fluid pressure increases as the continuous flow passes through each pump, much like how a multi-stage pump works. For example, if two of the same pumps are in series, the combined performance curve will have double the head of a single pump for a given flow rate. For two different pumps, the head is still added together on the combined pump curve, but the curve will most likely have a piecewise discontinuity.
(97) In situations where a high, constant pressure is required, speed control may need to be included with, for example, the first pump in such a system. This configuration achieves the high pressure that is needed, while keeping a low flow, because the fixed-speed pump feeds into the speed-controlled pump, which adjusts its output with a pressure transmitter to add only enough head to maintain a constant pressure. This device would combine the benefits of both designs in one product. Having two in series reduces RPMs needed for both to get same flow improvement.
(98) The disclosure is further described with the aid of the following Example.
EXAMPLE I
(99) A prior art IMPELLA 2.5® heart pump (Abiomed) pulls blood from the left ventricle through an inlet area near the tip and expels blood from the catheter into the ascending aorta. The IMPELLA 2.5® heart pump is designed to temporarily (≤6 hours) protect the patient hemodynamically during a high-risk procedure (e.g., in patients experiencing: advanced heart failure, cardiogenic shock, and/or post-cardiotomy cardiogenic shock). The IMPELLA 2.5® device is inserted into a patient via a standard catheterization procedure through the femoral artery, into the ascending aorta, across the valve and into the left ventricle. The IMPELLA 2.5® device is thought to stabilize hemodynamics, unloads the left ventricle, perfuses the end organs, and allows for recovery of the native heart.
(100) The IMPELLA 2.5® device spins at approximately 50,000 RPM with flows of 2.5 l/min on the highest possible setting. Reportedly, Abiomed's 5.0 device spins at 33,000 RPM with maximum flows of 5.3 l/min on the highest possible setting.
(101) The IMPELLA 2.5® device needs 55,000 RPMs (turns of impeller) to achieve 4.5 liters per minute flow at the level of the renal arteries for cardio-renal dysfunction recovery.
(102) Utilizing the device of
(103) The device of
(104)
(105) The IMPELLA 2.5® device needs to spin its impellers at 18,500 to 50,000 RPM to reach 4.5 liters per minute flow through the device, which increases risk of hemolysis and mechanical breakdown. The IMPELLA 2.5® device does not reach 4.5 liters per minute true flow in the patients with these RPMs, only these flow rates through the small orifices of the associated small diameter catheters. The actual patient flow improvement is less than ½ this device flow rate, i.e., under 2.25 liters per minute patient flow improvement.
(106) In certain embodiments, the device utilizes strong radial force deployment to maintain its position in the aorta and occupies nearly all (or all) of the entire inner diameter of the subject's aorta, and thus the 4.5 liters per minute flow through device is also 4.5 liters per minute flow improvement for the patient. The strong radial force utilized in the system limits repositioning of the device. Occupying this much of the aorta allows for the use of the relatively lower rpm of the device.
(107) Wireless power, which powers the device of
EXAMPLE II
(108) The herein described circulatory assist device is combined with a heart regeneration bioelectric stimulator, micro infusion pump, and mixed composition for implantation into a subject's aorta as described herein. In such a combination, the circulatory assist pump off loads work load from the heart, thus improving perfusion to improve regeneration results. The subject's heart recovers over time.
(109) Expression of desirable protein(s) may be accomplished via, e.g., implanted micro coils on the stent. See, e.g., the earlier incorporated US Patent publication US 2017/0266371 A1 to Leonhardt et al. (Sep. 21, 2017) and/or the earlier incorporated Macfelda et al. “Bioelectrical signals improve cardiac function and modify gene expression of extracellular matrix components” ESC Heart Failure 2017; 4: 291-300 (published online 30 Jun. 2017).
(110) As previously described, such micro coils too can utilize wireless energy. Wireless control extends to pulsatility, speed, and/or impeller angle of the various components of the system.
EXAMPLE III
(111) As depicted in
EXAMPLE IV
(112) A circulatory assist pump 10 (
(113) The encaged circulatory assist pump (
(114) The impeller blades are set to rotate at 7,500 rpm in a 20 mm aorta distended with stent radial force to 22 mm, thus producing an increase of 1.5 liters per minute flow from a starting base of 3.5 liters per minute increasing to 5.0 liters per minute total flow in the aorta just above the renal arteries. Dependent on, for example, the patient being treated, an optimal pump speed can be as high as 10,000 rpm.
(115) Computational fluid dynamics testing is conducted used to determine flow rates (particularly flow into the renal arteries), aortic pressure differential, and coronary flow rates, and thus brain and hemolysis risk.
EXAMPLE V
(116) A circulatory assist pump is made and encaged within a stent cage. The impeller blades have an impeller diameter of 13.5 mm long from tip to tip and are made of 17-4PH stainless steel.
(117) The impeller blades are set to rotate at 7,500 rpm in an open stent (outer diameter) aorta distended of 22.86 mm.
(118) The boundary conditions are as follows:
(119) Flow Inlet (L/min) of 3.5, 4.5, and 5.5.
(120) Impeller speeds (rpm) of 7,500, 10,500, and 15,000.
EXAMPLE VI
(121) An upper aortic pulsating stent graft useful herein has the following dimensions and specifications:
(122) Outer Diameter of 24 mm aortic stent for being placed, e.g., in a 20-22 mm aorta
(123) Total Length of 6 cm before placement in the 22 mm aorta (lengthens when compressed).
(124) Hoop Strength of 15.8 N/cm
(125) Radial Resistance Force of 1.27 N/cm
(126) Chronic Outward Force of 0.31 N/cm
(127) Three (3) pulsating wireless powered bands each 1.5 cm wide each wrapped around stent. Only one pulsates at any given time.
(128) Aortic stent is ¾'s covered in ePTFE (expanded polytetrafluoroethylene) matching with positions of pulsatile bands.
(129) Each pulse band on each pulsation moves covered stent inward into the aorta 3 mm (a 3 mm aortic pulse wave).
(130) Pulsation is time matched to natural pulses of the subject's heart (e.g., “native flow”) with a slight time delay for time for pulsed blood flow to reach the aorta.
EXAMPLE VII
(131) Powering an impeller pump positioned within a stent cage of