Abstract
The invention relates to a catheter device, comprising a drive shaft extending from a driving region of the catheter device to a distal end region of the catheter device, a rotor which is attached to the drive shaft in the distal end region and a distal bearing for bearing a distal end of the drive shaft. The distal bearing comprises a drive shaft cover which is configured to cover a section of the drive shaft extending distally of the rotor. On a distal side of the rotor, a radially inner part of the rotor is recessed with respect to radially outer parts of the rotor to form a hollow space surrounding the drive shaft, wherein a proximal end of the drive shaft cover lies in said hollow space.
Claims
1. A catheter device, comprising a drive shaft extending from a driving region of the catheter device to a distal end region of the catheter device, a rotor which is attached to the drive shaft in the distal end region, a distal bearing for bearing a distal end of the drive shaft, wherein the distal bearing comprises a drive shaft cover, the drive shaft cover being configured to cover a section of the drive shaft, which section extends distally of the rotor, characterized in that on a distal side of the rotor, a radially inner part of the rotor is recessed with respect to radially outer parts of the rotor to form a hollow space surrounding the drive shaft, wherein a proximal end of the drive shaft cover lies in said hollow space.
2. The catheter device according to claim 1, wherein a diameter of the hollow space is at least 0.5 mm and/or at most 2 mm; and/or in that a length of the hollow space is at least 0.5 mm and/or at most 2.5 mm.
3. The catheter device according to claim 1, designed as an expandable pump, wherein the rotor is located in a housing, the housing and the rotor being configured to be compressed at least along a radial direction extending transversely to a longitudinal direction, from an expanded state into a compressed state, and wherein upon compression of the housing, a relative motion of the rotor with respect to the distal bearing is effected, and wherein a penetration depth of the drive shaft cover over which it extends axially into the hollow space is chosen such that the proximal end of the drive shaft cover remains within the hollow space in the compressed state.
4. The catheter device according to claim 1, wherein the penetration depth of the drive shaft cover, over which it extends into the hollow space, is at least 0.3 mm and/or at most 2.2 mm.
5. The catheter device according to claim 1, wherein a wall thickness of a portion of the drive shaft cover extending into the hollow space is at least 0.03 mm and/or at most 0.3 mm, preferably at most 0.08 mm.
6. The catheter device according to claim 1, wherein an outer diameter of a proximal section of the drive shaft cover is smaller than an outer diameter of a section of the drive shaft cover lying distally thereof, wherein a portion of the proximal section extends into the hollow space, the outer diameter of the proximal section of the drive shaft cover preferably being at least 0.1 mm smaller than the outer diameter of the section of the drive shaft cover lying distally thereof and/or at most 0.6 mm smaller than the outer diameter of the section of the drive shaft cover lying distally thereof.
7. The catheter device according to claim 6, wherein the proximal section has a length of at least 0.6 mm and/or at most 2 mm.
8. The catheter device according to claim 1, wherein a radial gap which is formed inside the hollow space, between the drive shaft cover and the rotor, has a gap size of at least 0.01 mm and/or at most 0.2 mm; and/or characterized in that an axial gap of at least 0.2 mm and/or at most 1.5 mm remains between the proximal end of the drive shaft cover and a hub of the rotor.
9. The catheter device according to claim 1 wherein the rotor comprises a stiffening element surrounding the hollow space.
10. The catheter device according to claim 1, wherein the distal bearing comprises an end part, wherein a distal end of the drive shaft cover lies within the end part, the drive shaft cover preferably comprising a distal section with a diameter that is larger than a diameter of a section of the drive shaft cover lying proximally thereof, wherein said distal section lies in part inside the end part.
11. The catheter device according to claim 1, wherein the drive shaft cover comprises a pliable section, the pliable section preferably being arranged between a distal end of the rotor and a proximal end of an end part of the distal bearing.
12. The catheter device according to claim 1, wherein the pliable section is provided by having at least one opening in the drive shaft cover in said pliable section, the at least one opening connecting an inside of the drive shaft cover to an outside of the drive shaft cover, the at least one opening preferably comprising one or more slits.
13. The catheter device according to claim 12, wherein a flexible tube is provided around the pliable section of the drive shaft cover, covering the at least one opening at least in part.
14. The catheter device according to claim 13, wherein the flexible tube leaves a distal portion of the at least one opening uncovered and/or in that the flexible tube comprises one or more holes to allow fluid communication with a portion of the at least one opening and/or in that the drive shaft cover comprises one or more venting holes to allow fluid communication between the inside of the drive shaft cover and the outside of the drive shaft cover.
15. The catheter device according to claim 1, wherein an inner diameter of the drive shaft cover at the proximal end of the drive shaft cover is reduced with respect to an inner diameter of the drive shaft cover at the distal end of the drive shaft cover.
16. The catheter device according to claim 1, wherein the drive shaft cover comprises 35NLT and/or ceramics and/or a diamond-like-carbon coating and/or in that the drive shaft cover is manufactured from a single piece.
Description
[0131] Aspects and embodiments of the catheter device according to the application are exemplified in FIGS. 1 to 20.
[0132] FIG. 1 shows a catheter device which is positioned within the left ventricle of a heart;
[0133] FIG. 2 shows the distal end region of a catheter device;
[0134] FIG. 3 shows an enlarged section of the distal end region of a catheter device;
[0135] FIGS. 4a and b show schematic sketches of a section of the distal end region of a catheter device;
[0136] FIGS. 5a and b show schematic sketches of a section of the distal end region of a catheter device;
[0137] FIG. 6 shows the spiral sleeve;
[0138] FIGS. 7a and b show the rotor and the rotor housing in the expanded state (a) and in the compressed state (b);
[0139] FIGS. 8a and b show the catheter device with a rotor having a hollow space and the drive shaft cover extending into the hollow space;
[0140] FIGS. 9a-c show the catheter device from FIG. 8 with an additional flexible tube;
[0141] FIGS. 10a and b show the catheter device from FIG. 8 with a stiffening element provided in the rotor;
[0142] FIG. 11 shows a detailed view of the catheter device;
[0143] FIG. 12 shows a detailed view of a catheter device having a rotor with a stiffening element;
[0144] FIGS. 13a-c show different views of a drive shaft cover in a first embodiment;
[0145] FIGS. 14a-b show different views of a drive shaft cover in a second embodiment;
[0146] FIGS. 15a-b show different views of a drive shaft cover in a third embodiment;
[0147] FIG. 16a shows a drive shaft cover in a fourth embodiment;
[0148] FIG. 16b shows a section of a drive shaft cover in a fifth embodiment;
[0149] FIGS. 17a-b, 18a-b, 19a-b and 20a-b show different embodiments of the stiffening element, in each case in two different views.
[0150] FIG. 1 shows a catheter device 1 used as a blood pump. The catheter device 1 is introduced into a patient, such that a portion of the distal end region 8 of the catheter device 1 is positioned within the left ventricle 18.3 of the heart 18.1 of the patient. In a driving region 16 which can lie outside of the patient's body, a motor 17 is provided for driving a drive shaft 4. A portion of the drive shaft 4 is covered by a pliable sheath 5. The drive shaft 4 and the pliable sheath 5 extend from the driving region 16 to the distal end region 8, where a rotor 2, preferably configured as a compressible rotor, is driven by the drive shaft 4. The compressible rotor 2 is located within a compressible housing 3. The compressibility of the rotor 2 and the housing 3 is useful for introducing the rotor into the patient's body at a lower profile. During operation, the rotor 2 and the housing 3 are in an expanded state. The housing 3 prevents damage to heart tissue such as for instance the tendinous chords, as it prevents tissue from being sucked into the rotor 2 or becoming entangled with the rotor 2 or the drive shaft 4. The distal end of the drive shaft 4 lies within a distal bearing 9. The distal bearing comprises a drive shaft cover 11 and a polymer end part 10, the polymer end part preferably made of a flexible material, such as Pebax® or another flexible medical grade polymer, preferably with a “memory” characteristic, i.e. such that it regains its original shape after being deformed. The polymer end part comprises an elongated portion 10.1 which is provided around a part of the drive shaft cover 10. The polymer end part 10 further comprises a pigtail tip 10.2 to prevent damage to the heart 18.1 and the aortic valve 18.4 during pump placement. The rotor 2 and the drive shaft 4 can rotate in a rotating direction 4.1, such that a flow of blood away from the distal end, towards the proximal end is effected, i.e. a blood flow out of the left ventricle 18.3 into the aorta 18.2 and to other regions of the patient's body. A downstream tubing 6 is provided proximally of the rotor 2 and the rotor housing 3, which downstream tubing has a downstream opening 6.1 that lies proximally of the aortic valve 18.4, such that the blood passes the aortic valve within the downstream tubing 6 and can then stream into the aorta 18.2. The downstream tubing 6 is made of a flexible material, such that it can be compressed by the aortic valve 18.4 as the patient's heart 18.1 continues to pump. The downstream tubing 6 is typically expanded mainly due to the active blood flow generated by the rotor 2 during rotation.
[0151] FIG. 2 shows a cut through the distal end region 8 of the catheter device 1. The distal bearing 9 comprises the polymer end part 10 with the pigtail 10.2 and the elongated portion 10.1. On the proximal end, the elongated portion 10.1 is provided around a portion of a drive shaft cover 11. The drive shaft 4 extends into the distal bearing 4 and is borne by the drive shaft cover 11. The downstream tubing 6 is attached to the rotor housing 3 and extends proximally. The proximal end of the downstream tubing 6 is attached to the pliable sheath 5. Between the rotor 2 and the proximal side of the drive shaft cover 11, the drive shaft should be protected to avoid damage to the heart. This is achieved by the catheter device described in more detail in the following figures
[0152] FIG. 3 shows an enlarged portion of the end region 8 of the catheter device 1. In particular, the section of the distal bearing 9 which comprises the drive shaft cover 11 is shown. The drive shaft cover 11 extends from within the polymer end part 10, out of the polymer end part 10, into the rotor housing 3. The drive shaft 4 is made of one or more layers of coaxial windings which run spirally around a cavity extending axially at the center of the drive shaft. The winding direction of the coaxial windings can alternate from one layer to the next. This setup can improve the flexibility of the drive shaft. The outer diameter of the drive shaft lies in a range of about 0.4 to about 2 mm. Preferably, the outer diameter lies between 0.6 mm and 1.2 mm. Particularly preferably, the diameter lies between 0.8 mm and 1.0 mm. The drive shaft cover 11 is designed for bearing the drive shaft 4. It comprises a sleeve with a lumen in which the drive shaft 4 is inserted. The sleeve is preferably designed as a spiral sleeve 14 out of flat tape 14.1. The tape can for instance be made of MP35N® or 35NLT® or ceramics. The inner diameter of the spiral sleeve 14 is chosen such that the drive shaft 4 can be mounted but remains rotatable, while no large amounts of blood can enter the gap between the drive shaft 4 and the spiral sleeve 14. The inner diameter of the spiral sleeve 14 can for instance be chosen to be between 0.01 mm and 0.08 mm larger than the outer diameter of the drive shaft 4, preferably between 0.01 mm and 0.05 mm larger than the outer diameter of the drive shaft 4. The inner diameter of the spiral sleeve 14 is between 0.4 mm and 2.1 mm, preferably between 0.6 mm and 1.3 mm, particularly preferably between 0.8 mm and 1.1 mm. The thickness of the spiral sleeve 14 is between 0.05 mm and 0.4 mm. Such a spiral sleeve 14 provides flexibility, particularly in the region extending out of the polymer end part 10. Preferably, the flexibility of the drive shaft cover 11 is such that a kink in the drive shaft is avoided if the distal end region 8 of the catheter device 1 is bent. Furthermore, the flexibility of the drive shaft cover 11 is such that the drive shaft 4 remains centered within the housing 3 and the rotor 2 does not touch the housing 3. The proximal end of the spiral sleeve, preferably both ends of the spiral sleeve are face ground. Furthermore, the edges of the both ends of the spiral sleeve are rounded and smooth, preferably with a ten-point mean roughness of R.sub.z≤2 μm, according to the ISO 1302 standard. The drive shaft cover 11 can further comprise a heat conducting part 13 which can be designed as a tube which is provided around a portion of the spiral sleeve 14. The heat conducting tube or part 13 is made of a material with a higher thermal conductivity than the polymer end part 10, in particular it can be made of medical grade stainless steel, such as 1.4441 stainless steel. The heat conducting part 13, when designed as a tube, is provided at least around a portion of the spiral sleeve 14 which lies inside the polymer end part 10, in some embodiments, the heat conducting part 13 or tube extends out of the polymer end part 10, into a region within the housing 3 which can be configured to be in direct contact with the blood of the patient. In particular, the heat conducting part 13 designed as a tube can extend between 0.5 mm and 2 mm out of the polymer end part 10, preferably between 1 mm and 1.5 mm. The heat conducting part 13 or tube can have a thickness of between 0.05 mm and 0.5 mm. An inner diameter of the heat conducting tube can be between 0.5 mm and 2.6 mm, preferably between 0.7 mm and 1.8 mm, particularly preferably between 0.9 mm and 1.6 mm. If the heat conducting part 13 or tube is configured such that a portion of the outer side 13″ of the heat conducting part 13 or tube can be brought in direct contact with the blood of the patient, the area of the outer side (13″) of the heat conducting part 13 or tube which can be brought in contact with the blood of the patient is preferably smooth, for instance with a ten-point mean roughness of R.sub.z≤1.2 μm according to the ISO 1302 standard. The portion of the outer side 13″ of the heat conducting part 13 which is configured to lie within the polymer end part and be in contact with the polymer end part is preferably roughened, for instance by laser texturing or knurling, preferably with an average surface roughness of R.sub.a≥0.8 μm, according to the ISO 1302 standard. On the proximal side of the drive shaft cover 11, the rotor 2 with a rotor hub 2.1 is provided around the drive shaft 4. When in the operating state, in which the rotor is expanded, the rotor hub 2.1 is kept at an axial distance of between 0.2 mm and 0.7 mm from the drive shaft cover, preferably at a distance of between 0.25 mm and 0.4 mm. The hub 2.1 of the rotor is designed such that the rotor blades 2.2 can be brought close to the drive shaft cover 11. The hub 2.1 extends less than 0.5 mm past the rotor blades in distal direction, preferably, it extends less than 0.1 mm or not at all past the rotor blades in distal direction.
[0153] The heat conducting part (13), which can be designed as a tube, can be provided inside the polymer end part 10 independently from the spiral sleeve 14, for example if a different kind of bearing or no additional sleeve for bearing the drive shaft 4 is envisioned.
[0154] FIG. 4a shows a schematic of a section of the distal end region 8 of the catheter device 1. A portion of the spiral sleeve 14 extends out of the polymer end part 10. The inner side 13′ of the heat conducting part is in direct contact with the spiral sleeve 14 and can be rough in order to facilitate gluing the spiral sleeve 14 to the inner side 13′ of the heat conducting part 13. The bare portion of the spiral sleeve 14 extending out of the polymer end part 10 is highly flexible and follows even strong bending motion of the drive shaft 4 during operation. A portion of the heat conducting tube 13 also extends out of the polymer end part 10 to enable heat transfer. In this embodiment, heat is transferred from the heat conducting 13 tube directly to the blood. The heat conducting tube 13 can also extend further into the distal bearing 10 and cover the spiral sleeve 14 at least in all areas that lie inside the polymer end part 10. In an alternative embodiment, there is no heat conducting tube 13, but all other features are the same.
[0155] FIG. 4b shows a schematic of the same section of the distal end region 8 of the catheter device 1 as FIG. 4a. The drive shaft cover 11 further comprises a flexible tube 12′ around the outside of the spiral sleeve or a portion of the outside of the spiral sleeve. In the embodiment shown in FIG. 4b, the flexible tube 12′ runs around a proximal portion of the polymer end part 10, around a portion of the outer side 13″ of the heat conducting part 13 which reaches out of the polymer end part 10, and around the portion of the spiral sleeve 14 extending out of the polymer end part 10. The inner side 13′ of the heat conducting part is in direct contact with the spiral sleeve 14 and can be rough in order to facilitate gluing the spiral sleeve to the inner side 13′ of the heat conducting part 13. The flexible tube can be implemented as a shrink hose and can be made for instance of silicone or of Pebax® or of PU or of PET. For good heat conductivity, the flexible tube can have a small wall thickness, for instance smaller than 0.2 mm, in particular smaller than 0.02 mm. In this embodiment, heat is transferred from the heat conducting 13 tube to the blood through the flexible tube 12′. In an embodiment featuring a flexible tube 12′, rings made of flat tape can be provided on the inside of the flexible tube 12′ instead of a spiral sleeve. They can for example be made of MP35N® or 35NLT® or ceramics and have the same thickness and inner diameter as the spiral sleeve. In a possible embodiment with rings, the rings are arranged distant from each other.
[0156] FIG. 5a shows the same section as FIG. 4b, but with a flexible tube 12″ in a different configuration. The flexible tube 12″ can also be implemented as a shrink hose and be made of for instance of silicone or of PEBAX®, PU or PET. For good heat conductivity, the flexible tube can have a small wall thickness, for instance smaller than 0.2 mm, in particular smaller than 0.02 mm. The flexible tube 12″ is provided on the outside of the spiral sleeve 14, and it runs along the inner side 13′ of the heat conducting part 13 or tube and inside the polymer end part 10. In the embodiment shown here, the flexible tube 12″ extends all the way to the distal end of the spiral sleeve 14. In this configuration, a portion of the outer side 13″ of the heat conducting part 13 is configured to be in direct contact with the blood of the patient upon insertion of the catheter device 1 into a patient. Said portion is smooth, for instance with a ten-point mean roughness R.sub.z, according to the ISO 1302 standard, of R.sub.z≤1.2 μm.
[0157] FIG. 5b shows a similar configuration as FIG. 5a, with the flexible tube 12″ provided on the outside of the spiral sleeve 14, running on inner side (13′) of the heat conducting part 13 and inside the polymer end part 10. Different from FIG. 5a, the flexible tube 12″ does not extend all the way to the distal end of the spiral sleeve 14 such that a distal portion of the spiral sleeve is not covered by the flexible tube 12″. The heat conducting part 13, on the other hand, extends further to the distal end of the spiral sleeve 14 and thus a portion of its inner side 13′ is configured to be in direct contact with the spiral sleeve 14. In this configuration, said portion of the inner side 13′ of the heat conducting part 13 can be glued to the outside of the spiral sleeve 14. It is advantageous to provide a roughened surface on the inner side 13′ of the heat conducting part 13′. For instance, with an average surface roughness of R.sub.a≥0.8 μm, according to the ISO 1302 standard. Furthermore, to enable the application of glue between the heat conducting part 13 and the spiral sleeve 14, the heat conducting 13 when designed as a tube can have an inner diameter which is between 0.04 mm and 0.1 mm larger than the outer diameter of the spiral sleeve 14.
[0158] FIG. 6 shows the spiral sleeve 14. The ends are face ground and smooth. The flat tape 14.1 is shown in a cut-away. The winding 14.2 has a winding direction from proximal to distal, which is the opposite direction of the preferred rotating direction 4.1 of the drive shaft 4, when looking in distal direction. This way, a rotating part cannot get damaged or caught by a pointed tip at the proximal end of the spiral sleeve 14.
[0159] FIG. 7 shows the rotor 2 and the housing 3 and a cannula 15 in two states a and b. The rotor 2 and the housing 3 are configured to be transferred into the cannula 15, for instance by exerting a force at the proximal end of the pliable sheath 5. When transferred into the cannula, the rotor 2′ and the housing 3′ are compressed in a radial direction, from their expanded states 2,3 into their compressed states 2′,3′. The cannula 15 can be a cannula pertaining to the catheter device 1 or peel-away-sheath to aid the insertion of the catheter device 1 into the body of a patient. The housing 3 in the expanded state has a length 3.1. As the housing 3 is compressed to the compressed state 3′, the length increases to a length 3.1′. As the length changes, the relative position of the distal bearing 9 which is attached to the housing 3 with respect to the drive shaft 4 changes. The drive shaft cover 11 is designed such that the distal end of the drive shaft 4 remains within the drive shaft cover 11 as the housing 3 undergoes changes in length 3.2 while the two parts slide against each other.
[0160] FIG. 8a shows a view of the distal end region 8 of the catheter device 1, the catheter device 1 being designed essentially as shown for instance in FIG. 1.
[0161] The distal bearing 9 is provided for bearing the distal end of the drive shaft 4. The distal bearing 9 comprises the end part 10 and the drive shaft cover 11. The drive shaft cover 11 covers a section of the drive shaft 4 which extends between the rotor 2 and the end part 10. The drive shaft cover 11 thereby covers said section of the drive shaft 4 along a whole length of the section.
[0162] On a distal side of the rotor 2, a radially inner part of the rotor 2, in particular of the rotor hub 2.1 is axially recessed with respect to radially outer parts of the rotor 2 and the rotor hub 2.1 to form a hollow space 2.3 surrounding the drive shaft 4. The hollow space 2.3 is cylindrical and open towards the distal side. A proximal end of the drive shaft cover 11 lies in the hollow space 2.3. The section of the drive shaft 4 which protrudes from the drive shaft cover 11 at its proximal end is therefore protected by the portions of the rotor 2 surrounding it.
[0163] A proximal section 11.1 of the drive shaft cover 11 partially lies within the hollow space 2.3. The proximal section 11.1 has a first outer diameter. Distally thereof, a second central section 11.2 of the drive shaft cover 11 is provided with a second diameter that is larger than the first diameter. The central section 11.2 comprises one or more openings 11.4 to make it pliable. A distal section 11.3 is provided distally of the central pliable section 11.2. The distal section 11.3 has a third diameter which is larger than the second diameter and extends into the end part 10. A portion of the distal section 11.3 thereby remains outside of the end part 10 to enable efficient heat transfer away from the end part. Heat conductivity is enhanced in this version, since the drive shaft cover 11 is designed as a single heat conducting piece.
[0164] The housing 3, the drive shaft 4 and the drive shaft cover 11 as shown in FIG. 8 are designed to enable bending of the catheter device 1, in particular in the section lying between the distal end of the rotor 2 and the proximal end of the end part 10. Safe bending is possible even during operation of the catheter device, as kinks in the drive shaft can be advantageously avoided.
[0165] The drive shaft cover 11 comprises metal, for example 35NLT® and/or MP35N®, and/or ceramics and/or a diamond-like-carbon coating. It is manufactured from a single piece and designed as a single piece.
[0166] It is also possible to have a drive shaft cover with a different design extend into the hollow space 2.3 of the rotor 2. For instance it is possible, to have the hollow space of the rotor in combination with one of the drive shaft covers shown in FIGS. 4a to 5b, with the spiral sleeve extending into the hollow space. In this case, the proximal end of the spiral sleeve may be modified to a closed tube-structure, for example by welding, to avoid sharp edges which might damage the rotor, for instance if the spiral sleeves touches the rotor under extreme or unforeseen conditions.
[0167] FIG. 8b shows a setup that is similar to that of FIG. 8a, however the section of the drive shaft 4 extending distally of the rotor 2 is kept shorter than in the case of FIG. 8a. Thereby, the drive shaft 4 ends proximally of the pliable section 11.2 of the drive shaft cover 11. The drive shaft 4 extends over a length into the drive shaft cover that is at least the expected change in length 3.2 which the housing 3 undergoes under compression (cf. FIGS. 7a, b). This way, the drive shaft 4 does not escape the drive shaft cover in the compressed state, when the drive shaft cover is moved away from the rotor in distal direction. With this setup, damage to the drive shaft 4 in the shown section due to heavy deformation of the drive shaft cover can typically be avoided completely. The flexibility of the pliable central section 11.2 can then be tuned through the design of the openings 11.4 (in conjunction with the material properties of the drive shaft cover 11), without having to take into account the bending properties of the drive shaft 4.
[0168] FIG. 9a shows the catheter device 1 of FIG. 8 with an additional flexible tube 12 provided around the pliable central section 11.2 of the drive shaft cover 11. The flexible tube 12 is designed as a shrink hose, covering part of the one or more opening 11.4. The flexible tube 12 is made of a polymer. The thickness of the flexible tube can be between 5 μm and 100 μm, preferably between 10 μm and 50 μm. The flexible tube 12 changes the flexibility of the pliable section. In order to avoid damage to the drive shaft 4 and ensure safe operation of the catheter device, thickness and material of the flexible tube as well as its position and length are chosen in accordance with the bending properties of the flexible housing 3 and the drive shaft to obtain optimal bending properties of the catheter device 1. The flexible tube thereby helps to avoid ingestion of heart tissue between the drive shaft cover and drive shaft.
[0169] In the Example from FIG. 9a, the flexible tube 12 furthermore leaves a distal portion of the at least one opening 11.4 uncovered, thus providing a fluid path 19 through the hollow space, along the inside of the drive shaft cover 11 and through the uncovered openings 11. This enables a flow of blood from the inside of the drive shaft cover 11 (where the drive shaft 4 is located) to the outside. This can help to prevent clogging of the device and can serve as a cooling mechanism.
[0170] FIG. 9b shows a setup which is similar to the one from FIG. 9a. However, in the case of FIG. 9b, the flexible tube 12 extends over the whole portion of the drive shaft cover 11, in which the openings 11.4 are provided. In this setup, where the flexible tube extends along the whole section having the openings 11.4, fluid communication between the inside of the drive shaft cover 11 and the outside of the flexible tube 12 can nonetheless be provided, for instance by having openings (not shown) in the flexible tube 12. Such openings in the flexible tube are not limited to have a specific geometry. In one embodiment, openings of the flexible tube 12 are chosen such that only a portion or a part of the opening or openings 11.4 in the drive shaft cover 11 is left uncovered. In particular, if several slits are provided in the drive shaft cover 11, each of the slits can be partially covered by the flexible tube 12. This way, the desired bending properties and the desired amount of fluid communication can be maintained, while reducing the risk of ingestion of heart tissue into the drive shaft cover 11 through the openings 11.4 of the drive shaft cover 11.
[0171] FIG. 9c shows a setup that is similar to the one from FIG. 9b in the sense that the flexible tube 12 extends over all of the openings 11.4. This way, the openings 11.4 can be designed for optimal bending properties and it is not necessary to adapt the design to prevent suction of tissue into the openings 11.4. A fluid path 19 similar to the one from FIG. 9a is established by having additional venting holes 11.5 which are provided in the drive shaft cover 11, distally of the openings 11.4 of the pliable central section 11.2, and distally of the flexible tube 12. A setup of this type can have the further advantage that the bending properties can be tuned via the flexible tube 12 along the whole length of the pliable section. Thereby, the flexible tube can remain fully intact, yet a blood flow through the drive shaft cover 11 is possible. The venting holes 11.5 can be designed such that the region where they are located remains stiff, i.e. the venting holes can have a design that is different from the openings 11.4. The venting holes 11.5 are typically not limited to a specific shape. The venting holes 11.5 can be optimized for the intended blood flow and they can be optimized to avoid suction of tissue into the venting holes 11.5.
[0172] FIG. 10a once again shows the catheter device 1 of FIG. 8. This time, the rotor 2 is equipped with a stiffening element 2.4 surrounding the hollow space 2.3. The stiffening element 2.4 is a hollow cylinder which is embedded into the material of the rotor 2 and extends at least along a full length of the hollow space 2.3. Specifically, in the example shown in FIG. 10, it is approximately twice as long as the hollow space 2.3, the stiffening element 2.4 having a length of for instance between 1.8 and 2.2 mm. In other possible embodiments it extends only over part of the length of the hollow space. The stiffening element 2.4 is used to prevent or reduce deformation of the rotor hub 2.1 during operation. An inner surface of the stiffening element 2.4 can also be left uncovered in an alternative embodiment (cf. FIG. 12). The stiffening element 2.4 may comprise microscopic and/or macroscopic structures to provide better attachment of the stiffening element to the rotor 2. These microscopic or macroscopic structures can for instance be designed as anchoring structures (cf. FIG. 10b) or indentations or holes, in particular through-holes, into which holes the material of the rotor 2 can penetrate (cf. FIGS. 17-20). If holes are provided, they may have a diameter of for instance at least 0.05 mm to allow the material of the rotor to enter the holes. If a stiffening element 2.3 is provided, a radial gap within the hollow space 2.3, lying between the outside of the drive shaft cover and the rotor 2, can be made smaller. If no stiffening element 2.4 is provided, the radial gap might need to be larger in order to avoid touching of the parts due to possible ovalization of the rotor hub 2.1 during operation. The hollow space 2.3 should be present immediately after compression of the rotor 2, in order for the drive shaft cover 11 to be able to move back into position after being moved away or pulled out of the hollow space 2.3 during compression of the rotor (as described in the context of FIG. 7).
[0173] FIG. 10b shows the catheter device 1 with the stiffening element 2.4. The stiffening element 2.4 comprises macroscopic anchoring elements 2.5 protruding radially outwards on two opposing sides of the stiffening element 2.4. The anchoring elements 2.5 are thereby located in areas where the blades 2.2 are attached to the hub 2.1 of the rotor 2. This way, it is possible to have anchoring elements 2.5 extending beyond the diameter of the hub 2.1 and into the material of the blades 2.2. The anchoring elements 2.5 are designed such that they still allow compression of the rotor 2 (i.e., folding of the rotor blades 2.2) as shown for instance in FIG. 7b, without damaging the rotor blades 2.2. In the present example, in order to allow the compression of the rotor, the anchoring elements 2.5 extend for example at most 1 mm or most 0.5 mm past the hub 2.1 and into the blades 2.2. The anchoring elements 2.5 can further comprise one or more recesses, indentations or undercuts into which the material of the rotor 2 may penetrate. The macroscopic protrusions can also be combined with holes and/or indentations.
[0174] The flexible tube 12 from FIGS. 9a-c and the stiffening element 2.4, as shown for instance in FIGS. 10a-c, can of course be combined in an advantageous embodiment of the catheter device according to this application. These embodiments are also compatible with the shorter drive shaft 4 as shown in FIG. 8b.
[0175] FIG. 11 shows the catheter device 1 with a detailed view of the area around the hollow space 2.3. In the detailed view, the proximal section 11.1 of the drive shaft cover 11 can be seen as it penetrates into the hollow space 2.3.
[0176] The hollow space 2.3 has a length l.sub.h of between 0.9 mm and 1.1 mm. A penetration depth p of the proximal section 11.1 into the hollow space is between 0.3 mm and 0.7 mm, leaving some space between the proximal end of the drive shaft cover 11 and the rotor 2 to avoid touching of the parts.
[0177] Thereby, the penetration depth p is chosen such that lengthening of the housing 3 as shown for instance in FIGS. 7a and b can be tolerated. In particular, as the housing 3 is compressed, the distal bearing 9 and thus the drive shaft cover 11 are displaced in distal direction with respect to the rotor 2 and the drive shaft 4. This displacement is for instance equivalent to the change in length 3.2. The penetration depth p is chosen larger than said displacement in order to ensure that the drive shaft 4 remains inside the drive shaft cover 4 at all times, also during insertion of the catheter device into a patient, i.e., in the compressed state when the drive shaft cover 11 is moved away from the rotor 2 in distal direction.
[0178] Typically, a distance of at least 0.3 mm and at most 0.6 mm is provided in axial direction between the parts as an axial gap (l.sub.h−p). The axial gap allows for clearance under the expected bending loads occurring during use of the pump.
[0179] A radial gap between the parts of the rotor 2 radially delimiting the hollow space 2.3 and an outer surface of the drive shaft cover is between 0.07 mm and 0.13 mm to avoid touching of the parts upon for example ovalization of the rotor 2, i.e., ovalization of the rotor hub 2.1. It is advantageous to keep a diameter d.sub.h of the cylindrical hollow space 2.3 as small as possible. A constraint for an inner diameter d.sub.i1 of the proximal section 11.1 of the drive shaft cover 11 is however given by the diameter of the drive shaft 4. A wall thickness w of the proximal section 11.1 of the drive shaft cover 11 is therefore chosen to be as small as possible. In this example, the wall thickness w is between 0.05 mm and 0.07 mm. Given a typical diameter of the drive shaft 4, the diameter d.sub.h of the hollow space may for instance be between 1.1 mm and 1.3 mm to achieve a radial gap given by d.sub.h−w−d.sub.i1, having the above-described dimensions.
[0180] An inner diameter d.sub.i1 of the drive shaft cover in the proximal section 11.1 is thereby chosen in accordance with an outer diameter of the drive shaft 4 to provide good bearing of the drive shaft 4 while enabling rotation of the drive shaft 4 without unnecessary wear and tear.
[0181] Some of the proximal section 11.1 remains outside of the hollow space 2.3. Thus, the diameter of the drive shaft cover 11 increases at a distance from a distal end of the rotor 2, depending on the length of the proximal section, for instance at least 0.3 mm away from the distal end of the rotor 2 (cf. FIG. 13b).
[0182] FIG. 12 shows an enlarged view of a section of the catheter device 1 with the stiffening element 2.4 provided around the hollow space. Here, the stiffening element 2.4 delimits the hollow space 2.3, having no additional material of the rotor on the inside of hollow cylinder that is the stiffening element 2.4. The stiffening element is made of a bio-compatible material. It can comprise MP35N and/or Nitinol and/or stainless steel and/or ceramics. It has a wall thickness of between 0.04 mm and 0.07 mm. It may have indentations on the outside, in order to better engage with the material of the rotor.
[0183] FIGS. 13a-c show three different views of the drive shaft cover 11.
[0184] FIG. 13a shows a perspective view. The proximal section 11.1, having the smallest diameter, the central section 11.2, having an increased diameter, and the distal section 11.3, having the largest diameter can be seen. The central section is typically pliable. Pliability can be provided by having openings or slits in the central section (cf. FIGS. 14-16). The pliable central section 11.2 can thereby be limp or flexible with a memory-effect, in the sense that the pliable section 11.2 regains its original shape after deformation. For better visibility, no slits are shown in FIGS. 13a-c. A device as shown in FIG. 13, without any slits, can be provided as a single piece and the slits can be cut into the single piece for manufacturing the drive shaft cover 11, using for instance a laser.
[0185] The slits 11.4 can be arranged such that a so-called hypotube-design is achieved. Examples of such hypotube-designs are for instance shown in FIGS. 14a-16b.
[0186] In the distal section, which is provided inside the end part 10, indentations are provided on the outside of the drive shaft cover. This way, a material of the end part, such as a polymer, may enter the indentations and thus form a particularly stable connection with the distal section 11.3.
[0187] In FIG. 13b, a schematic side view is shown. Outer diameter and length of each section are visible. The proximal section 11.1 has a first length l.sub.1 which is between 0.9 mm and 1.1 mm. If it penetrates the hollow space 2.3 as described above, by between 0.3 mm and 0.7 mm, a remainder of the proximal section 11.1 remains outside of the hollow space 2.3. The length of the proximal section may be chosen such that a length of the remainder of the proximal section 11.1 remaining outside of the hollow space is the same as the length of the axial gap. An outer diameter d.sub.1 can be for instance between 0.9 mm and 1.1 mm, depending on a diameter of the drive shaft 4.
[0188] Distally of the proximal section 11.1, a central section 11.2 is provided. The outer diameter d.sub.2 of the central section 11.2 is between 0.14 mm and 0.3 mm larger than d.sub.1. The length l.sub.2 of the central section 11.2 can be for instance between 5 and 8 mm.
[0189] The distal section 11.3 has a length l.sub.3 which can be between 5 and 8 mm and an outer diameter d.sub.3 which is larger than d.sub.2. The outer diameter d.sub.3 can be for instance between 1.25 mm and 1.6 mm. Furthermore, on the outer surface of the distal section 11.3, axial and circumferential grooves are realized for a solid connection to the end part 10.
[0190] In FIG. 13c, a cut through the drive shaft cover 11 is shown, exposing the inside of the drive shaft cover 11 where the drive shaft 4 is located during operation. An inner diameter d.sub.i1 at the proximal end of the drive shaft cover 11 is smaller than an inner diameter d.sub.i2 at its distal end. The diameter is thereby changed in a smoothened step, between the proximal section 11.1 and the central section 11.2, the inner diameter being kept constant through-out the central section 11.2 and the distal section 11.3. A difference in diameter between d.sub.a and d.sub.i2 is between 0.02 mm and 0.12 mm. Having a smooth transition between the different inner diameters helps to avoid wear of the drive shaft.
[0191] FIGS. 14a and b show different views of the drive shaft cover 11, the drive shaft cover 11 having a pliable central section 11.2.
[0192] FIG. 14a shows a perspective view. An opening 11.4 designed as a spiral slit extends essentially over the whole length of the central section 11.2. The slit connects an inside of the drive shaft cover 11 to an outside of the drive shaft cover 11 such that the remaining material of the central section 11.2 forms a spiral sleeve.
[0193] FIG. 14b shows a corresponding side view. The spiral slit can have a width s of for instance between 0.005 mm and 0.2 mm, preferably between 0.025 mm and 0.1 mm. The width s of the slit can be tuned to achieve the desired bending properties. It can also be chosen in such a way that blood circulation through the slit is possible. Edges of the slit can be rounded to avoid wear on the drive shaft, tissue, or a flexible tube.
[0194] The pitch of the spiral can also be chosen according to the desired bending properties. The pitch can therefore change along a length of the spiral, having a first pitch associated with a length first length p.sub.1 at the distal end of the spiral and a second pitch associated with a second length p.sub.2 at the proximal end of the spiral, wherein p.sub.1 is for example larger than p.sub.2. The pitch may also be kept constant in an embodiment of the drive shaft cover.
[0195] The pitch may be for instance between 0.5 mm and 0.8 mm.
[0196] The slit can be cut into the drive shaft cover 11 using a laser.
[0197] FIGS. 15a and b show the same views as FIGS. 14a and b, but for a different slit arrangement. In the case of FIG. 15, several slits extending tangentially in the pliable central section 11.2 are provided. In fact, the course of the slits does not have an axial component, i.e., they run circumferentially with no pitch. It is however possible to provide a multitude of slits with an axial component.
[0198] In the setup shown in FIG. 15, several pairs of slits are provided at in the central section 11.2, each pair of slits comprising two slits arranged at the same height of the central section 11.2 and running almost halfway around the central section, leaving two bridges m on opposing sides, each bridge m having a width of for instance between 0.05 mm and 0.2 mm. The pairs of slits are arranged at a distance r from one another.
[0199] In one embodiment, the width of the slits arranged as in FIG. 15 is the same as that of the slits as shown in FIG. 14. Due to the circumferential arrangements, the slits may however also be wider than the slits shown in FIG. 14. The pairs of slits are arranged at a distance of between 0.3 mm and 1 mm from one another, the bridges m of the pairs of slits being arranged at different angles from one pair of slits to the next. In the case of FIG. 15, at 0° and 180° for the first pair of slits, and at 90° and 270° for the second pair of slits and so forth in an alternating fashion.
[0200] The widths of the slits can be the same as in the case of the spiral slit and they can also be cut using a laser.
[0201] The distance r between the slits, as indicated in FIG. 15b, corresponding to a width of the material between the slits, can be larger than the widths of the slits in one embodiment. It is however also possible, to make the distance r between the slits small, in an exemplary embodiment even smaller than the width of the slits, in order to allow bending of the pliable central section 11.2 through deformation of the material of width r between the slits.
[0202] In particular in a setup of this type, where the material of width r between the slits can be deformed, it is also possible to have more than two slits arranged at the same height, for instance three slits at the same height, each slit running around less than a third of the circumference, in this case having three bridges, for instance of the above-described width. Then, bending of the pliable section can be enabled via deformation of the material of width r between the slits, rather than deformation of the bridges. It is of course also possible to have more than three slits and three bridges, such as for instance four slits and four bridges.
[0203] FIG. 16a shows a perspective view of the drive shaft cover 11, with a pliable central section 11.2 having several openings 11.4. The openings 11.4 are designed as slits with a tangential component and an axial component. All slits have the same pitch. The slits are intertwined spiral sections, each slit running 240° around the central section and each slit having through-holes at both ends. In each case, three slits of the above-described type are provided at the same height, starting at 120° from one another, on the circumference of the drive shaft cover. The width s of the slits can be the same as in the case of FIGS. 14 and 15. The through-holes which are provided at both ends of each slit have a cross section with a geometry that may be optimized for preventing tearing or rupturing of the drive shaft cover upon strong deformation. They may be for example circular or drop-shaped. They may have a diameter or edge length that is larger than the width of the slits, in particular they may have a diameter of edge length of for instance between 0.05 mm and 2 mm.
[0204] FIG. 16b shows a portion of the pliable central section 11.2 of the drive shaft cover 11. Thereby, the slits 11.4 run all the way around the drive shaft cover, resulting in several rings or segments. The design allows for full flexibility within the constraints of the laser cut width. Two segments are shown in the Figure. The cut structure can be repeated axially at a given distance, resulting in more segments of the shown type. The segments are held together by an undercut design: A left segment has a recess and a right segment has a protrusion lying in the recess of the left segment, thus connecting the two segments, similar to pieces of a jigsaw-puzzle. Several pairs of recesses and protrusions of this type are arranged on the circumference of the segments, so that the segments do not disengage as they are moved with respect to each other. For instance at least 2 recess-protrusion pairs or at least 3 recess-protrusion pairs or at least 4 recess-protrusion pairs are provided. While the segments are connected in said fashion, no material bridges are provided between the segments.
[0205] The slit 11.4 is wide enough to provide play between the two segments, rendering the section pliable, more specifically, rendering the section limp. The section has a minimal bending radius that is limited by the play provided by the slit 11.4, i.e., bending is only possible to a certain degree, until the segments abut.
[0206] A restoring force for straightening the drive shaft cover after it has been bent can be provided for instance by providing the flexible tube 12 around the pliable section 11.2 of the drive shaft cover 11.
[0207] FIGS. 17 to 20 show different embodiments of the stiffening element 2.4, in each case providing a side view displayed in subfigure a) and a perspective view displayed in subfigure b).
[0208] All of the stiffening elements 2.4 shown in FIGS. 17 to 20 may have a length l.sub.s that is chosen in accordance with the length of the hollow space 2.3 of the rotor 2. The length l.sub.s may be for instance twice the length of the hollow space 2.3, for instance between 1.8 mm and 2.2 mm.
[0209] The stiffening elements 2.4 may be made of a bio-compatible material. They may comprise one or more of MP35N, 35NLT, Nitinol, stainless steel (in particular medical grade stainless steel), and ceramics.
[0210] An inner diameter d.sub.is of the stiffening element 2.4, in the case of each of the embodiments shown in FIGS. 17-20, may be chosen to at least the diameter of the hollow space 2.3.
[0211] An outer diameter d.sub.os may be chosen to be smaller than an outer diameter of the hub 2.1 of the rotor.
[0212] A wall thickness of the stiffening element, may, in each case, be for instance at least 0.03 mm, preferably at least 0.04 mm and/or at most 0.08 mm, preferably at most 0.07 mm.
[0213] In the case of FIGS. 17a and b, the stiffening element is designed as a tube, having through-holes near one end of the stiffening element. The through-holes may be provided in a section of the rotor lying proximally of the hollow space 2.3, the portion of the stiffening element 2.4 without any through-holes extending along the hollow space 2.3, in particular delimiting the hollow space. I.e., in this case the inside the portion without any holes may remain exposed (cf. FIG. 12). In this case, d.sub.is is then equal to the diameter of the hollow space 2.3.
[0214] The section having through-holes, which can extend proximally of the hollow space 2.3 can be completely surrounded by the material of the rotor. The material of the rotor may penetrate through the through-holes, enabling a particularly reliable connection between the rotor 2 and the stiffening element 2.4. A cross section of the holes is circular. It is however not limited to this specific geometry. They may be circular or polygonal. The holes have a diameter of between 0.03 mm and 0.5 mm.
[0215] FIGS. 18a and b show an embodiment of the stiffening element 2.4, wherein through-holes are provided along the full length of the stiffening element 2.4. In this case, d.sub.is can for example be chosen to be larger than the diameter of the hollow space 2.3. The stiffening element 2.3 can then be completely surrounded by the material of the rotor 2 or the rotor hub 2.1. I.e., a thin layer of material pertaining to the hub 2.1 of the rotor can be provided on the inside of the stiffening element 2.4 in the region of the hollow space 2.3 (cf. FIG. 10). This way, the stiffening element 2.4 is not exposed. The holes have a diameter of between 0.3 mm and 0.5 mm.
[0216] FIGS. 19a and b show an embodiment of the stiffening element 2.4 which is similar to the one shown in FIG. 17, i.e. suitable to be used in a setup as shown for instance in FIG. 10. The through-holes provided in the stiffening element 2.4 of FIG. 19 are however smaller and have a diameter of between 0.02 mm and 0.1 mm.
[0217] FIGS. 20a and b show an embodiment of the stiffening element 2.4, the stiffening element being designed as stent-like structure. The stent-like structure comprises three rings, one at each end and one being provided centrally.
[0218] The application further relates to the following aspects: [0219] 1. A catheter device (1), comprising: [0220] a rotor (2,2′) located at the distal end region (8) of the catheter device (1); [0221] a drive shaft (4) extending from a driving region (16) of the catheter device (1) to the distal end region (8) of the catheter device (1); [0222] a distal bearing (9) for bearing a distal end of the drive shaft (4); and [0223] wherein [0224] the distal bearing (9) comprises a heat conducting part (13) configured to enable heat transfer away from the distal bearing. [0225] 2. A catheter device according to aspect 1, characterized in that the heat conducting part (13) is designed as a tube surrounding the drive shaft. [0226] 3. A catheter device (1) according to any one of aspects 1 or 2, characterized in that the drive shaft (4) comprises a cavity extending axially with the drive shaft and wherein the drive shaft comprises a plurality of coaxial windings which run spirally around the cavity of the drive shaft, the windings within different coaxial layers having opposite winding directions and in that the outer diameter of the drive shaft lies in a range of about 0.4 mm to about 2 mm, preferably comprising a reinforcement element which is provided sectionally in the cavity of the drive shaft (4) in the distal end region. [0227] 4. A catheter device (1) according to any one of aspects 1 to 3, characterized in that the heat conducting part (13) extends out of the distal bearing (9), into an area which is configured to be brought in contact with the fluid, enabling heat transfer from the distal bearing (9) to the fluid. [0228] 5. A catheter device (1) according to any one of aspects 1 to 4, characterized in that the distal bearing (9) comprises a polymer end part (10) or the distal bearing (9) comprises a polymer end part which comprises a region which is designed as a pigtail (10.2). [0229] 6. A catheter device (1) according to any one of aspects 1 to 5, characterized in that the heat conducting part (13) is made of a medical grade stainless steel, preferably made of 1.4441 stainless steel. [0230] 7. A catheter device (1) according to any one of aspects 1 to 6, characterized in that an inner diameter of the heat conducting part (13) designed as a tube is between 0.5 mm and 2.6 mm and/or in that the heat conducting part (13) has a thickness between 0.05 mm and 0.5 mm. [0231] 8. A catheter device (1) according to any one of aspects 1 to 7, characterized in that a spiral sleeve (14) with a winding is arranged within the distal bearing (9), for rotatably mounting the distal end of the drive shaft (4) inside the spiral sleeve (14), such that the spiral sleeve (14) lies at least in part inside the heat conducting part (13) designed as a tube and/or such that a portion of the spiral sleeve (14) is in direct contact with a portion of the inner side (13′) of the heat conducting part (13) [0232] 9. A catheter device (1) according to any one of aspects 1 to 8, characterized in that a spiral sleeve (14) with a winding is arranged within the distal bearing (9), for rotatably mounting the distal end of the drive shaft (4) inside the spiral sleeve (14), such that a portion of the spiral sleeve (14) and a portion of the heat conducting part (13) are only separated by a thin flexible tube (12,12′) which is provided around a portion of the outside of the spiral sleeve, wherein the flexible tube (12,12′) is preferably designed as a shrink hose. [0233] 10. A catheter device (1) according to aspect 8 or 9, characterized in that the spiral sleeve (14) is made of flat tape (14.1). [0234] 11. A catheter device (1) according to any one of aspects 1 to 10, characterized in that a portion of the outer side (13″) of the heat conducting part (13) which is configured to be brought in contact with the fluid is smooth, preferably with a ten-point mean roughness of R.sub.z≤1.2 μm, and in that an inner side (13′) of the heat conducting part (13) is rough to facilitate gluing the spiral sleeve (14) to the inner side (13′) of the heat conducting part (13), the inner side (13′) of the heat conducting part or tube (13) preferably having an arithmetic average surface roughness of R.sub.a≥0.8 μm. [0235] 12. A catheter device (1) according to aspect 11, characterized in that a further portion of the outer side (13″) of the heat conducting part or tube (13), which is configured to lie inside the polymer end part (10), is roughened, preferably having an arithmetic average surface roughness of R.sub.a≥0.8 μm. [0236] 13. A catheter device (1) according to any one of aspects 8 to 12, characterized in that both ends of the spiral sleeve (14) are face ground and all edges of both ends are rounded and smooth, preferably with a ten-point mean roughness of R.sub.z2 μm. [0237] 14. A catheter device (1) according to any one of aspects 8 to 13, characterized in that an inner diameter of the spiral sleeve (14) is between 0.4 mm and 2.1 mm, and in that the spiral sleeve has a thickness between 0.05 mm to 0.4 mm. [0238] 15. A catheter device (1) according to any one of aspects 8 to 14, wherein the rotor (2) and the drive shaft (4) are configured to rotate in a rotating direction (4.1) such that a flow of fluid in a proximal direction is effected, if the catheter device (1) is brought in contact with a fluid, characterized in that, when looking along the drive shaft towards a distal end of the drive shaft, the winding direction of the spiral sleeve (14) from a proximal end of the spiral sleeve (14) to a distal end of the spiral sleeve (14), is the opposite direction of the rotating direction (4.1) of the rotor (2) and the drive shaft (4), when looking along the drive shaft (4) towards a distal end of the drive shaft (4). [0239] 16. A catheter device (1) according to any one of aspects 8 to 15, characterized in that the spiral sleeve (14) is made out of MP35N®, 35NLT®, or ceramics. [0240] 17. A catheter device (1) according to any one of aspects 1 to 16, designed as an expandable pump, characterized in that a cannula (15) is provided around a portion of the drive shaft which lies in the vicinity of the rotor (2) and in that the rotor (2) is located in a housing (3), the housing (3) and the rotor (2) being configured to be transferred at least in part into the cannula (15), wherein the housing (3) and the rotor (2) are compressed at least along a radial direction extending transversely to a longitudinal direction, from an expanded state into a compressed state. [0241] 18. A catheter device (1) according to aspect 17, wherein, upon application of a force at the proximal end of the catheter and/or compression of the housing (3) and the rotor (2), a relative motion of the drive shaft (4) with respect to the distal bearing (9) is effected, and wherein the drive shaft (4) and the distal bearing (9) are configured such that the distal end of the drive shaft (4) remains within the distal bearing (9) or within the heat conducting part (13) designed as a tube or within the spiral sleeve (14) when the housing (3) and the rotor (2) are compressed. [0242] 19. A catheter (1) device according to any one of aspects 1 to 18, characterized in that a hub (2.1) pertaining to the rotor (2) extends less than 0.5 mm past the rotor blades (2.2) towards the distal end of the catheter device, preferably less than 0.1 mm. [0243] 20. A catheter device (1), comprising: [0244] a rotor (2) located at the distal end region of the catheter device (1); [0245] a drive shaft (4) extending from a driving region (16) of the catheter device (1) to the distal end region (8) of the catheter device; [0246] a distal bearing (9) for bearing a distal end of the drive shaft; and [0247] wherein [0248] the distal bearing (9) comprises a spiral sleeve (14) with a winding, configured for rotatably mounting the distal end of the drive shaft (4) inside the spiral sleeve (14). [0249] 21. A catheter device (1) according to aspect 20, characterized in that the spiral sleeve (14) is made of flat tape (14.1). [0250] 22. A catheter device (1) according to any one of aspects 20 or 21, characterized in that the drive shaft (4) comprises a cavity extending axially with the drive shaft (4) and wherein the drive shaft (4) comprises a plurality of coaxial windings which run spirally around the cavity of the drive shaft (4), the windings within different coaxial layers having opposite winding directions. and in that the outer diameter of the drive shaft lies in a range of about 0.4 mm to about 2 mm, preferably comprising a reinforcement element which is provided sectionally in the cavity of the drive shaft (4) in the distal end region. [0251] 23. A catheter device (1) according to any one of aspects 20 to 22, characterized in that both ends of the spiral sleeve (14) are face ground and all edges of both ends are rounded and smooth, preferably with a ten-point mean roughness of R.sub.z≤2 μm. [0252] 24. A catheter device according to any one of aspects 20 to 23, characterized in that a flexible tube (12, 12′) is provided around a portion of the outside of the spiral sleeve, wherein the flexible tube is preferably designed as a shrink hose. [0253] 25. A catheter device (4) according to any one of aspects 20 to 24, wherein the rotor (2) and the drive shaft (4) are configured to rotate in a rotating direction (4.1) such that a proximally directed flow of fluid is effected, if the catheter device (1) is brought in contact with a fluid, characterized in that, when looking along the drive shaft (4) towards a distal end of the drive shaft, the winding direction of the spiral sleeve (14) from a proximal end of the spiral sleeve (14) to a distal end of the spiral sleeve (14), is the opposite direction of the rotating direction (4.1) of the rotor (2) and the drive shaft (4), when looking along the drive shaft towards a distal end of the drive shaft. [0254] 26. A catheter device (1) according to any one of aspects 20 to 25, characterized in that the spiral sleeve (14) is made out of MP35N®, 35NLT®, or ceramics. [0255] 27. A catheter device (1) according to any one of aspects 20 to 26, characterized in that an inner diameter of the spiral sleeve (14) is between 0.4 mm and 2.1 mm and in that the spiral sleeve has a thickness between 0.05 mm to 0.4 mm. [0256] 28. A catheter device (1) according to any one of aspects 20 to 27, characterized in that the spiral sleeve (14) and/or the flexible tube (12,12′) is at least in part in contact with a heat conducting part (13), the heat conducting part (13) being configured to enable heat transfer away from the distal bearing (9) and/or the spiral sleeve (14). [0257] 29. A catheter device according to aspect 28, characterized in that the heat conducting part (13) is designed as a tube surrounding a portion of the spiral sleeve (14). [0258] 30. A catheter device according to aspect 28 or 29, characterized in that the heat conducting part or tube (13) extends out of the distal bearing, into an area which is configured to be brought in contact with a fluid, enabling heat transfer from the distal bearing (9) to the fluid. [0259] 31. A catheter device (1) according to any one of aspects aspect 20 to 30, characterized in that the distal bearing (9) comprises a polymer end part (10) or the distal bearing (9) comprises a polymer end part which comprises a region which is designed as a pigtail (10.2). [0260] 32. A catheter device (1) according to any one of aspects 28 to 31, characterized in that a portion of the outer side (13″) of the heat conducting part (13) which is configured to be brought in contact with the fluid is smooth, preferably with a ten-point mean roughness of R.sub.z≤1.2 μm, and in that an inner side (13′) of the heat conducting part (13) is rough to facilitate gluing the spiral sleeve (14) to the inner side (13′) of the heat conducting part (13), the inner side (13′) of the heat conducting part or tube (13) preferably having an arithmetic average surface roughness of R.sub.a≥0.8 μm. [0261] 33. A catheter device according to aspect 32, characterized in that a further portion of the outer side (13″) of the heat conducting part or tube (13) which is configured to lie inside the polymer end part is roughened, preferably having an arithmetic average surface roughness of R.sub.a≥0.8 μm. [0262] 34. A catheter device according to any one of aspects 28 to 33, characterized in that an inner diameter of the heat conducting part (13) designed as a tube is between 0.5 mm and 2.6 mm and/or in that the heat conducting part has a thickness between 0.05 mm and 0.5 mm. [0263] 35. A catheter device according to any one of aspects 28 to 34, characterized in that the heat conducting part (13) is made of a medical grade stainless steel, preferably made of 1.4441 stainless steel. [0264] 36. A catheter device (1) according to any one of aspects 20 to 35, designed as an expandable pump, characterized in that a cannula is provided around a portion of the drive shaft (4) which lies in the vicinity of the rotor (2) and in that the rotor (2) is located in a housing (3), the housing (3) and the rotor (2) being configured to be transferred at least in part into the cannula (15), wherein the housing (3) and the rotor (2) are compressed at least along a radial direction extending transversely to a longitudinal direction, from an expanded state into a compressed state. [0265] 37. A catheter device (1) according to any one of aspects 20 to 36, wherein, upon application of a force at the proximal end of the catheter and/or compression of the housing and the rotor, a relative motion of the drive shaft (4) with respect to the distal bearing (9) is effected, and wherein the drive shaft and the distal bearing are configured such that the distal end of the drive shaft remains within the spiral sleeve (14) when the housing (3) and the rotor (2) are compressed. [0266] 38. A catheter device (1) according to any one of aspects 20 to 37, characterized in that a hub (2.1) pertaining to the rotor (2) extends less than 0.5 mm past the rotor blades (2.2) towards the distal end of the catheter device, preferably less than 0.1 mm. [0267] 39. A catheter device (1), comprising: [0268] a rotor (2) located at the distal end region of the catheter device (1); [0269] a drive shaft (4) extending from a driving region (16) of the catheter device (1) to the distal end region (8) of the catheter device; [0270] a distal bearing (9) for bearing a distal end of the drive shaft; [0271] wherein [0272] the distal bearing (9) comprises a spiral sleeve (14) with a winding, configured for rotatably mounting the distal end of the drive shaft (4) inside the spiral sleeve (14); [0273] and wherein the spiral sleeve (14) or a flexible tube (12, 12′), which is provided around a portion of the outside of the spiral sleeve, is at least in part in contact, with a heat conducting part (13), the heat conducting part (13) being configured to enable heat transfer away from the distal bearing (9) and/or the spiral sleeve (14).
LIST OF REFERENCE NUMERALS
[0274] 1 Catheter Device [0275] 2 Rotor [0276] 2′ Rotor (compressed state) [0277] 2.1 Hub [0278] 2.2 Rotor blade [0279] 2.3 Hollow space [0280] 2.4 Stiffening element [0281] 2.5 Anchoring element [0282] 3 Housing [0283] 3′ Housing (compressed state) [0284] 3.1 Length of the housing [0285] 3.1′ Length of the housing (compressed state) [0286] 3.2 Change in length of the housing [0287] 4 Drive shaft [0288] 4.1 Rotating direction of the drive shaft [0289] 5 Pliable Sheath [0290] 6 Downstream tubing [0291] 6.1 Downstream opening [0292] 8 Distal end region [0293] 9 Distal bearing [0294] 10 End part [0295] 10.1 Elongated portion of the polymer end part [0296] 10.2 Pigtail [0297] 11 Drive shaft cover [0298] 11.1 Proximal section [0299] 11.2 Central section [0300] 11.3 Distal section [0301] 11.4 Opening [0302] 11.5 Venting hole [0303] 12 Flexible tube [0304] 12′ Flexible tube (outside configuration) [0305] 12″ Flexible tube (inside configuration) [0306] 13 Heat conducting part [0307] 13′ Inner side of the heat conducting part [0308] 13″ Outer side of the heat conducting part [0309] 14 Spiral sleeve [0310] 14.1 Flat tape [0311] 14.2 Winding of the spiral sleeve [0312] 15 Cannula [0313] 16 Driving region [0314] 17 Motor [0315] 18.1 Heart [0316] 18.2 Aorta [0317] 18.3 Left ventricle [0318] 18.4 Aortic valve [0319] 19 Fluid Path
