VENTRICULAR ASSIST DEVICE

Abstract

The disclosure in particular relates to a ventricular assist device for implantation into a lumen of a blood vessel, comprising an impeller fixed to a rotor shaft, wherein the impeller is configured to rotate around a longitudinal axis of the rotor shaft; a drive unit comprising a magnetic motor configured to cause rotation of the impeller around to the longitudinal axis; a first active magnetic bearing configured to bear a first end section of the rotor shaft relative to the drive unit; a second active magnetic bearing configured to bear a second end section of the rotor shaft relative to the drive unit; and a control unit configured to control the magnetic motor, the first active magnetic bearing and the second active magnetic bearing.

Claims

1. Ventricular assist device for implantation into a lumen of a blood vessel, comprising: an impeller fixed to a rotor shaft, wherein the impeller is configured to rotate around a longitudinal axis of the rotor shaft; a drive unit comprising a magnetic motor configured to cause rotation of the impeller around the longitudinal axis; a first active magnetic bearing configured to bear a first end section of the rotor shaft relative to the drive unit; a second active magnetic bearing configured to bear a second end section of the rotor shaft relative to the drive unit; a control unit configured to control the magnetic motor, the first active magnetic bearing and the second active magnetic bearing; wherein the first active magnetic bearing comprises: a first radial magnetic bearing configured to adjust a radial position of the first end section relative to the first radial magnetic bearing, a first radial sensor unit configured to determine the radial position of the first end section; and/or wherein the second active magnetic bearing comprises: a second radial magnetic bearing configured to adjust a radial position of the second end section relative to the second radial magnetic bearing, a second radial sensor unit configured to determine the radial position of the second end section.

2. The ventricular assist device according to claim 1, wherein the control unit is configured to: control the magnetic motor to adjustably generate a magnetic force on the rotor shaft to control a rotational speed of the impeller; and/or control the first active magnetic bearing to adjustably generate a magnetic force on the first end section to control a first position of the first end section relative to the first active magnetic bearing; and/or control the second active magnetic bearing to adjustably generate a magnetic force on the second end section to control a second position of the second end section relative to the second active magnetic bearing.

3. (canceled)

4. The ventricular assist device according to claim 1, wherein the first radial magnetic bearing comprises at least two first bearing segments, wherein the first radial sensor unit comprises a first radial sensor configured to measure a capacitance between each of the first bearing segments and the first end section, and wherein the first radial sensor is configured to determine the radial position of the first end section based on the measured capacitance between each of the first bearing segments and the first end section; and/or wherein the second radial magnetic bearing comprises at least two second bearing segments, wherein the second radial sensor unit comprises a second radial sensor configured to measure a capacitance between each of the second bearing segments and the second end section, and wherein the second radial sensor is configured to determine the radial position of the second end section) based on the measured capacitance between each of the second bearing segments and the second end section.

5. The ventricular assist device according to claim 4, wherein each of the first and second bearing segments comprises: a magnetic yoke arranged adjacent the first and second end section, respectively; and a radial magnetic coil, wherein the radial magnetic coil is wound around the magnetic yoke.

6. The ventricular assist device according to claim 4, wherein the at least two first bearing segments are substantially identically constructed; and/or wherein the at least two second bearing segments are substantially identically constructed.

7. The ventricular assist device according to claim 4, wherein the at least two first bearing segments are substantially equally spaced in a circumferential direction around the longitudinal axis; and/or wherein the at least two second bearing segments are substantially equally spaced in a circumferential direction around the longitudinal axis.

8. The ventricular assist device according to claim 1, wherein: the first radial sensor unit comprises a first radial Hall sensor arrangement configured to determine the radial position of the first end section; and/or the second radial sensor unit comprises a second radial Hall sensor arrangement configured to determine the radial position of the second end section, the first radial Hall sensor arrangement comprises a first permanent magnet fixed to the first end section, and at least one first radial Hall sensor arranged adjacent the first permanent magnet in a radial direction relative to the longitudinal axis, and/or the second radial Hall sensor arrangement comprises a second permanent magnet-fixed to the second end section, and at least one second radial Hall sensor arranged adjacent the second permanent magnet in the radial direction relative to the longitudinal axis.

9. (canceled)

10. The ventricular assist device according to claim 1, wherein the first radial sensor unit is configured to provide the determined radial position of the first end section to the control unit, wherein the control unit is configured to control the first radial magnetic bearing of the first active magnetic bearing to adjustably generate a magnetic force on the first end section on the basis of the determined radial position of the first end section; and/or wherein the second radial sensor unit is configured to provide the determined radial position of the second end section to the control unit, and wherein the control unit is configured to control the second radial magnetic bearing of the second active magnetic bearing to adjustably generate a magnetic force on the second end section on the basis of the determined radial position of the second end section.

11. The ventricular assist device according to claim 1, wherein the first radial magnetic bearing is one of a homopolar magnetic bearing and a heteropolar magnetic bearing, and/or wherein the second radial magnetic bearing is one of a homopolar magnetic bearing and a heteropolar magnetic bearing.

12. The ventricular assist device according to claim 1, wherein the ventricular assist device comprises an axial sensor arrangement configured to determine an axial position of the rotor shaft along the longitudinal axis, and wherein the axial sensor arrangement comprises: a ring-shaped permanent magnet fixed to the rotor shaft in a circumferential direction around the rotor shaft, and an axial Hall sensor arranged adjacent the ring-shaped permanent magnet in a direction parallel to the longitudinal axis, wherein the axial Hall sensor is configured to determine the axial position of the rotor shaft.

13. (canceled)

14. The ventricular assist device according to claim 12, wherein the first active magnetic bearing comprises a first axial magnetic bearing configured to adjust the axial position of the rotor shaft along the longitudinal axis, and/or wherein the second active magnetic bearing) comprises a second axial magnetic bearing configured to adjust the axial position of the rotor shaft along the longitudinal axis.

15. The ventricular assist device according to claim 14, wherein the determined axial position is provided to the control unit, and wherein the control unit is configured to control the first axial magnetic bearing of the first active magnetic bearing and/or the second axial magnetic bearing of the second active magnetic bearing) to adjust the axial position of the rotor shaft on the basis of the determined axial position of the rotor shaft.

16. The ventricular assist device according to claim 1, wherein the control unit comprises: a transmitter configured to transmit data to a remote device, wherein the control unit is preferentially configured to detect a malfunction of the ventricular assist device and subsequently transmit an alert on the basis of the detected malfunction; and/or a receiver configured to receive data from a remote device; and/or a data storage device, wherein the data storage device is configured to store historical operational data of the ventricular assist device.

17. The ventricular assist device according to claim 1, wherein a geometry of the ventricular assist device is configured such that a flow field of a fluid pumped by the ventricular assist device does not comprise any dead water zones, and wherein the geometry of the ventricular assist device is preferentially configured such that the fluid pumped by the ventricular assist device does not flow over any sharp edges of the ventricular assist device.

18. The ventricular assist device according to claim 1, wherein the magnetic motor is configured to cause rotation of the impeller in at least one of: a pulsatile operation mode; a counter-pulsatile operation mode; and a continuous operation mode.

19. The ventricular assist device according to claim 1, wherein the ventricular assist device comprises a power unit configured to provide power to the ventricular assist device, wherein the power unit comprises at least one of: a power reception unit configured to, preferentially wirelessly and transcutaneously, receive power; and a power storage unit configured to store power.

20. The ventricular assist device according to claim 1, wherein the magnetic motor is a brushless DC-motor, and wherein the brushless DC-motor preferably has a large airgap.

21. The ventricular assist device according to claim 1, wherein the first active magnetic bearing and the second active magnetic bearing are substantially identically constructed.

22. The ventricular assist device according to claim 1, wherein the blood vessel is one of a vein and an artery of a user, preferentially a pulmonary artery or an aorta of the user.

23. The ventricular assist device according to claim 1, wherein the ventricular assist device comprises one or more attachment elements on an outer surface of the ventricular assist device configured to fix the ventricular assist device to the blood vessel; and/or wherein the ventricular assist device is configured to be fixable to the blood vessel by one or more fixing elements arranged outside the lumen of the blood vessel; and/or wherein the ventricular assist device is configured to be fully implanted into the lumen of the blood vessel.

Description

[0097] In particular, the Figures show:

[0098] FIG. 1: a perspective, exploded view of an exemplary ventricular assist device;

[0099] FIG. 2: a perspective view of a ventricular assist device 1 in the operational state;

[0100] FIG. 3: a schematic cross-sectional view of an exemplary ventricular assist device 1;

[0101] FIG. 4A: a cross-sectional view of a first active magnetic bearing 30A of a ventricular assist device 1;

[0102] FIG. 4B: a cross-sectional view of a first active magnetic bearing 30A of FIG. 4A along the line A-A;

[0103] FIG. 4C: a cross-sectional view of a second active magnetic bearing 30B of a ventricular assist device 1;

[0104] FIG. 5: an organ of balance 50 of a pectinid;

[0105] FIG. 6: a schematic view of a first radial sensor unit of the ventricular assist device 1;

[0106] FIG. 7: a schematic view of a first radial sensor unit of the ventricular assist device 1;

[0107] FIG. 8: a cross-sectional view of a ventricular assist device 1;

[0108] FIG. 9: a cross-sectional view of a ventricular assist device 1;

[0109] FIG. 10: a FEMM (Finite Element Method Magnetics) simulation result of a magnetic field produced by an exemplary first magnetic bearing segment 33A;

[0110] FIG. 11: a cross-sectional view of a fluid flow 1000 through a ventricular assist device 1;

[0111] FIG. 12: the fluid field 1000 of FIG. 11 as a perspective, cross-sectional 3D flow body;

[0112] FIG. 13: a cross-sectional view of an exemplary ventricular assist device after implantation into a lumen of a blood vessel; and

[0113] FIG. 14: a perspective view of an exemplary impeller geometry;

[0114] FIG. 15: a schematic view of magnetic field lines of a permanent magnet.

[0115] In the following description of the Figures, identical components are provided with identical reference signs, unless otherwise specified for the respective figure description.

[0116] FIG. 1 shows a perspective, exploded view of an exemplary ventricular assist device 1. The ventricular assist device 1 is shown to have a substantially cylindrical shape.

[0117] The ventricular assist device comprises in particular a rotor shaft 10. The rotor shaft 10 is shown as arranged in the operational state of the ventricular assist device 1 in relation to the drive unit 20. Specifically, an impeller 11 fixed to the rotor shaft 10 is arranged fully inside the drive unit 20, and can therefore not be seen in FIG. 1. The rotor shaft 10 has a longitudinal axis that is substantially identical to a central axis of the ventricular assist device 1, wherein the rotor shaft 10 is configured to rotate around the longitudinal axis and/or the central axis. Furthermore, the rotor shaft 10 comprises a non-magnetisable section 190, a first magnetisable element 191A, a first non-magnetisable element 192A, a second magnetisable element 191B, and a second non-magnetisable element 1926. The first magnetisable element 191A and the first non-magnetisable element 192A may form, in the shown embodiment, a first end section 19A of the rotor shaft 10. The second magnetisable element 191B and the second non-magnetisable element 1926 may form, in the shown embodiment, a second end section 19B of the rotor shaft 10.

[0118] The ventricular assist device 1 further comprises the drive unit 20. The drive unit 20 is configured to have a substantially cylindrical shape, wherein the impeller 11 of the rotor shaft 10 is arranged within the drive unit 20 in the operational state. The drive unit 20 furthermore comprises a magnetic motor (not shown in FIG. 1) configured to cause rotation of the impeller 11 and the rotor shaft 10 around the longitudinal axis and the central axis during operation of the ventricular assist device 1.

[0119] The ventricular assist device 1 further comprises a first active magnetic bearing 30A. The first active magnetic bearing 30A is configured to bear the first end section 19A of the rotor shaft 10 relative to the drive unit 20 and relative to the first active magnetic bearing 30A.

[0120] The ventricular assist device 1 further comprises a second active magnetic bearing 30B. The second active magnetic bearing 30B is configured to bear the second end section 19B of the rotor shaft 10 relative to the drive unit 20 and relative to the second active magnetic bearing 30B.

[0121] Although the first active magnetic bearing 30A and the drive unit 20 are shown as separated for illustrative purposes in FIG. 1, the first active magnetic bearing 30A is configured to be fixedly connected to the drive unit 20 on a first side of said drive unit 20 in the operational state of the ventricular assist device 1. Similarly, the second active magnetic bearing 30B and the drive unit 20 are shown as separated for illustrative purposes in FIG. 1, the second active magnetic bearing 30B is configured to be fixedly connected to the drive unit 20 on a second side of said drive unit 20 in the operational state of the ventricular assist device 1. In particular, the first side of the drive unit 20 is located opposite of the second side of the drive unit 20 along the central axis of the ventricular assist device 1.

[0122] FIG. 2 shows a perspective view of a ventricular assist device 1 in the operational state.

[0123] In particular, in the shown embodiment, the first active magnetic bearing 30A is fixedly connected to the drive unit 20. Furthermore, the second active magnetic bearing 30B is fixedly connected to the drive unit 20.

[0124] The drive unit 20 may in particular comprise a, preferentially substantially cylindrical, outer body 21. Specifically, each of the first active magnetic bearing 30A and the second active magnetic bearing 30B may be fixedly connected to the outer body 21.

[0125] The drive unit may further comprise access covers 22, wherein each access cover is removably connected to the outer body 21. In particular, each access cover may configured to be removable to access at least the magnetic motor of the drive unit 20.

[0126] The first active magnetic bearing 30A may comprise in particular a first radial magnetic bearing 31A configured to adjust a radial position of the first end section 19A relative to the first radial magnetic bearing 31A. The first radial magnetic bearing 31A comprises in the shown embodiment four first bearing segments 33A, wherein said first bearing segments 33A are arranged circumferentially, specifically equally spaced, around the central axis and/or the longitudinal axis of the rotor shaft 10 in the operational state of the ventricular assist device 1. Each of the four first bearing segments 33A is in particular arranged substantially adjacent the rotor shaft 10 and/or the first end section 19A in the operational state of the ventricular assist device 1.

[0127] Each of the first bearing segments 33A furthermore comprises a control unit cover 34A located adjacent to the respective first bearing segment 33A. Each control unit cover 34A is in particular configured to seal a corresponding control unit and/or control sub-unit from a fluid to be pumped by the ventricular assist device 1.

[0128] Furthermore, the four first bearing segments 33A are substantially identically constructed.

[0129] The second active magnetic bearing 30B may comprise in particular a second radial magnetic bearing 31B (not shown due to the perspective of FIG. 2) configured to adjust a radial position of the second end section 19B relative to the second radial magnetic bearing 31B. The second radial magnetic bearing 31B comprises in the shown embodiment four second bearing segments 33B, wherein said second bearing segments 33B are arranged circumferentially, specifically equally spaced, around the central axis and/or the longitudinal axis of the rotor shaft 10 in the operational state of the ventricular assist device 1. Each of the four second bearing segments 33B is in particular arranged substantially adjacent the rotor shaft 10 and/or the second end section 19B in the operational state of the ventricular assist device 1.

[0130] Each of the second bearing segments 33B furthermore comprises a control unit cover 34B located adjacent to the respective second bearing segment 33B. Each control unit cover 34B is in particular configured to seal a corresponding control unit and/or control sub-unit from a fluid to be pumped by the ventricular assist device 1.

[0131] Furthermore, the four second bearing segments 33B are substantially identically constructed.

[0132] FIG. 3 shows a schematic cross-sectional view of an exemplary ventricular assist device 1.

[0133] In particular, the first active magnetic bearing 30A comprises at least a first radial magnetic bearing 31A configured to bear the first end section 19A (shown as a single end section of the rotor shaft 10 for simplicity) of the rotor shaft 10. Furthermore, the second active magnetic bearing 30B comprises at least a second radial magnetic bearing 31B configured to bear the second end section 19B (shown as a single end section of the rotor shaft 10 for simplicity) of the rotor shaft 10.

[0134] The ventricular assist device 1 further comprises an impeller 11 fixedly connected with the rotor shaft 10, wherein the impeller 11 is configured to be rotatable with the rotor shaft 10 around the longitudinal axis of the rotor shaft 10 and/or the central axis of the ventricular assist device 1. The ventricular assist device 1 may further comprise a mounting body 12, wherein the mounting body 12 is fixedly connected to the rotor shaft 10. The mounting body 12 is in particular configured such that further elements of the ventricular assist device 1 can easily be mounted on the rotor shaft 10. However, the mounting body 12 is not essential, and said further elements may also be directly mounted on the rotor shaft 10.

[0135] Furthermore, the ventricular assist device 1 comprises a plurality of permanent drive magnets 13, preferably six permanent drive magnets 13, wherein each permanent drive magnet 13 is fixedly connected to a bracket 14. Each bracket 14 is fixedly connected to the mounting body 12, thereby providing a fixed connection between each of the permanent drive magnets 13 and the rotor shaft 10. In particular, the six permanent drive magnets 13 are equally spaced in a circumferential direction around the rotor shaft 10 and/or the central axis. In particular, the plurality of permanent drive magnets 13 are fixed relative to the rotor shaft 10 at a location downstream of the impeller 11. In other words, the plurality of permanent drive magnets 13 are fixed relative to the rotor shaft 10 at a location such that during operation of the ventricular assist device 1, a pumped fluid flows through the impeller 11 prior to flowing past the plurality of permanent drive magnets 13.

[0136] Furthermore, the ventricular assist device 1 comprises an axial sensor arrangement 23 (see for example FIG. 9) configured to determine an axial position of the rotor shaft 10 along the longitudinal axis and/or the central axis in the operational state. In particular, the axial sensor arrangement 23 may comprise any type of sensor capable of detecting and/or measuring the axial position of the rotor shaft 10 along the longitudinal axis and/or the central axis in the operational state relative to the drive unit 20 and/or the first active magnetic bearing 30A and/or the second active magnetic bearing 30B. For simplicity, an exemplary sensor is not shown in FIG. 3.

[0137] In particular, the axial sensor arrangement 23 comprises a ring-shaped permanent magnet 15 fixed relative to the rotor shaft 10 in a circumferential direction around the rotor shaft 10. Specifically, in the shown embodiment, the ring-shaped permanent magnet 15 is fixed to the mounting body 12, and therewith fixed to the rotor shaft 10. Furthermore, the ring-shaped permanent magnet 15 may be formed from any possible magnetic material. The ring-shaped permanent magnet 15 may be arranged along the rotor shaft 10 at a location in between the impeller 11 and the plurality of permanent drive magnets 13.

[0138] The axial sensor arrangement 23 may further comprise an axial Hall sensor 23A (not shown in FIG. 3) arranged adjacent the ring-shaped permanent magnet 15 in a direction parallel to the longitudinal axis, wherein the axial Hall sensor 23A is configured to determine the axial position of the rotor shaft 10.

[0139] The first active magnetic bearing 30A furthermore comprises a first axial magnetic bearing 32A configured to adjust the axial position of the rotor shaft 10 along the longitudinal axis and/or the central axis. In particular, the first axial magnetic bearing 32A is configured to adjustably generate a magnetic force on the rotor shaft 10 to adjust the axial position of the rotor shaft 10 along the longitudinal axis and/or the central axis.

[0140] Furthermore, the rotor shaft 10 comprises a first magnetisable disk 16, specifically a first ring-shaped planar magnetisable disk 16, fixed to the rotor shaft 10, preferably to the non-magnetisable section 190 of the rotor shaft 10. The first magnetisable disk 16 is fixed to the rotor shaft 10 such that the longitudinal axis is normal to the first magnetisable disk 16. In particular, the first axial magnetic bearing 32A may be configured to adjustably generate a magnetic force on the first magnetisable disk 16 to adjust the position of the rotor shaft 10 along the longitudinal axis and/or the central axis.

[0141] In particular, the first axial magnetic bearing 32A may comprise a first axial magnetic coil. In particular, the first axial magnetic coil is arranged adjacent the first magnetisable disk 16. The first axial magnetic coil is wound around the longitudinal axis and/or the central axis in the operational state. Furthermore, the first axial magnetic coil is configured such that the rotor shaft 10 is rotatable with respect to the first axial magnetic coil. Furthermore, a control unit may be configured to control a current to the first axial magnetic coil to adjustably generate a magnetic force on the rotor shaft 10 to adjust the axial position of the rotor shaft 10 along the longitudinal axis and/or the central axis, preferentially based on the axial position of the rotor shaft 10 as determined by the axial sensor arrangement 23.

[0142] The second active magnetic bearing 30B furthermore comprises a second axial magnetic bearing 32B configured to adjust the axial position of the rotor shaft 10 along the longitudinal axis and/or the central axis. In particular, the second axial magnetic bearing 32B is configured to adjustably generate a magnetic force on the rotor shaft 10 to adjust the axial position of the rotor shaft 10 along the longitudinal axis and/or the central axis.

[0143] Furthermore, the rotor shaft 10 comprises a second magnetisable disk 17, specifically a second ring-shaped planar magnetisable disk 17, fixed to the rotor shaft 10, preferably to the non-magnetisable section 190 of the rotor shaft 10. The second magnetisable disk 17 is fixed to the rotor shaft 10 such that the longitudinal axis is normal to the second magnetisable disk 17. In particular, the second axial magnetic bearing 32B may be configured to adjustably generate a magnetic force on the second magnetisable disk 17 to adjust the position of the rotor shaft 10 along the longitudinal axis and/or the central axis.

[0144] In particular, the second axial magnetic bearing 32B may comprise a second axial magnetic coil. In particular, the second axial magnetic coil is arranged adjacent the second magnetisable disk 17. The second axial magnetic coil is wound around the longitudinal axis and/or the central axis in the operational state. Furthermore, the second axial magnetic coil is configured such that the rotor shaft 10 is rotatable with respect to the second axial magnetic coil. Furthermore, a control unit may be configured to control a current to the second axial magnetic coil to adjustably generate a magnetic force on the rotor shaft 10 to adjust the axial position of the rotor shaft 10 along the longitudinal axis and/or the central axis, preferentially based on the axial position of the rotor shaft 10 as determined by the axial sensor arrangement 23.

[0145] FIG. 4A shows a cross-sectional view of a first active magnetic bearing 30A of a ventricular assist device 1.

[0146] In particular, the first active magnetic bearing 30A comprises a first radial magnetic bearing 31A configured to adjust a radial position of the first end section 19A, specifically of the first magnetisable element 191A, relative to the first radial magnetic bearing 31A, and a first radial sensor unit configured to determine the radial position of the first magnetisable element 191A relative to the first radial magnetic bearing 31A. The first radial magnetic bearing 31A is configured to adjustably generate a magnetic force on the first magnetisable element 191A to control the radial position of the first magnetisable element 191A relative to the first radial magnetic bearing 31A. Specifically, the first radial magnetic bearing 31A is configured to adjustably generate a magnetic force on the first magnetisable element 191A along a substantially radial direction relative to the longitudinal axis of the rotor shaft 10 and/or relative to the central axis. Specifically, the first radial magnetic bearing 31A is implemented as an exemplary homopolar magnetic bearing in the shown embodiment.

[0147] The first radial magnetic bearing 31A comprises four first bearing segments 33A, wherein said first bearing segments 33A are arranged circumferentially and equally spaced around the central axis and/or the longitudinal axis of the rotor shaft 10 in the operational state of the ventricular assist device 1. In the exemplary cross-section shown, two first bearing segments 33A are illustrated. Each of the four first bearing segments 33A is arranged substantially adjacent the rotor shaft 10, specifically the first magnetisable element 191A, in the operational state of the ventricular assist device 1.

[0148] Furthermore, the first radial sensor unit comprises a first radial sensor configured to measure a capacitance between each of the first bearing segments 33A, specifically a magnetic yoke 37A of the respective first bearing segment 33A, and the first magnetisable element 191A. Said first radial sensor will be further explained with respect to FIGS. 5 to 7.

[0149] Furthermore, each of the first bearing segments 33A comprises a magnetic yoke 37A arranged adjacent the first magnetisable element 191A in the operational state of the ventricular assist device 1. The magnetic yoke 37A may be at least partially formed from a magnetisable material, such as for example magnetisable stainless steel 1.4016. Additionally, each of the first bearing segments 33A comprises one first radial magnetic coil 36A, wherein said first radial magnetic coil 36A is wound around the magnetic yoke 37A. A close-up view of the magnetic yoke 37A is illustrated for example in FIG. 6 below.

[0150] A control unit of the ventricular assist device comprises a plurality of control sub-units 35A, wherein each of the first bearing segments 33A is provided with one of said control sub-units 35A. Each control sub-unit 35A is configured to control a current supplied to the respective first radial magnetic coil 36A of the respective first bearing segment 33A to adjustably generate a magnetic force on the first magnetisable element 191A to adjust the radial position of the first magnetisable element 191A relative to the first radial magnetic bearing 31A. Each control sub-unit 35A is in particular implemented on a printed circuit board, and provided with a control unit cover 34A. Each control unit cover 34A is in particular configured to seal the corresponding control sub-unit 35A from a fluid to be pumped by the ventricular assist device 1.

[0151] Furthermore, the four first bearing segments 33A are substantially identically constructed, and substantially equally spaced in a circumferential direction around the longitudinal axis and/or the central axis.

[0152] Additionally, the first radial sensor unit comprises a first radial Hall sensor arrangement configured to determine the radial position of the first end section 19A. In particular, the first radial Hall sensor arrangement comprises a first permanent magnet 193A fixed to the first end section 19A, specifically fixed to the first non-magnetisable element 192A of the first end section 19A, and at least one first radial Hall sensor 38A arranged adjacent the first permanent magnet 193A in a radial direction relative to the longitudinal axis and/or the central axis in the operational state of the ventricular assist device 1. Said first permanent magnet 193A fixed to the first non-magnetisable element 192A of the first end section 19A is not shown in FIG. 4A, but will be further explained with respect to FIG. 9. The first radial Hall sensor arrangement comprises four first radial Hall sensors 38A, wherein the four first radial Hall sensors 38A are equally spaced in a circumferential direction around the longitudinal axis and/or the central axis in the operational state of the ventricular assist device 1. Specifically, each first radial Hall sensor 38A is arranged adjacent to one of the first bearing segments 33A.

[0153] The first radial Hall sensor arrangement may further be shielded from the first radial magnetic bearing 31A by one or more shielding elements arranged between the first radial Hall sensor arrangement and the first radial magnetic bearing 31A. In particular, each first radial Hall sensor 38A may be shielded from the respective adjacent first bearing segment 33A by one or more shielding elements.

[0154] FIG. 4B shows a cross-sectional view of a first active magnetic bearing 30A of FIG. 4A along the line A-A. For brevity, components already discussed with respect to FIG. 4A will not be further discussed for FIG. 4B.

[0155] The first active magnetic bearing 30A further comprises a structural segment ring 60. The segment ring 60 may be formed for example from a non-magnetisable material. Furthermore, each of the first bearing segments 33A are fixedly connected to the segment ring 60. Furthermore, each of the one or more control unit covers 34A and/or the respective control sub-units 35A may also be fixedly connected to the segment ring 60. Finally, the one or more first radial Hall sensors 38A may also be mounted on said segment ring 60. The segment ring 60 therefore acts as a mounting platform for components of the first active magnetic bearing 30A, and may further be fixedly connected to the drive unit 20.

[0156] FIG. 4C shows a cross-sectional view of a second active magnetic bearing 30B of a ventricular assist device 1. In particular, the second active magnetic bearing 30B is substantially identically constructed to the first active magnetic bearing 30A. Thereby, a facile production of the ventricular assist device can be achieved.

[0157] In particular, the second active magnetic bearing 30B comprises a second radial magnetic bearing 31B configured to adjust a radial position of the second end section 19B, specifically of the second magnetisable element 191B, relative to the second radial magnetic bearing 31B, and a second radial sensor unit configured to determine the radial position of the second magnetisable element 191B relative to the second radial magnetic bearing 31B. The second radial magnetic bearing 31B is configured to adjustably generate a magnetic force on the second magnetisable element 191B to control the radial position of the second magnetisable element 191B relative to the second radial magnetic bearing 31B. Specifically, the second radial magnetic bearing 31B is configured to adjustably generate a magnetic force on the second magnetisable element 191B along a substantially radial direction relative to the longitudinal axis of the rotor shaft 10 and/or relative to the central axis. Specifically, the second radial magnetic bearing 31B is implemented as an exemplary homopolar magnetic bearing in the shown embodiment.

[0158] The second radial magnetic bearing 31B comprises four second bearing segments 33B, wherein said second bearing segments 33B are arranged circumferentially and equally spaced around the central axis and/or the longitudinal axis of the rotor shaft 10 in the operational state of the ventricular assist device 1. In the exemplary cross-section shown, two second bearing segments 33B are illustrated. Each of the four second bearing segments 33B is arranged substantially adjacent the rotor shaft 10, specifically the second magnetisable element 191B, in the operational state of the ventricular assist device 1.

[0159] Furthermore, the second radial sensor unit comprises a second radial sensor configured to measure a capacitance between each of the second bearing segments 33B, specifically a magnetic yoke 37B of the respective second bearing segment 33B, and the second magnetisable element 191B. Said second radial sensor will be further explained with respect to FIGS. 5 to 7.

[0160] Furthermore, each of the second bearing segments 33B comprises a magnetic yoke 37B arranged adjacent the second magnetisable element 191B in the operational state of the ventricular assist device 1. The magnetic yoke 37B may be at least partially formed from a magnetisable material, such as for example magnetisable stainless steel 1.4016. Additionally, each of the second bearing segments 33B comprises one second radial magnetic coil 36B, wherein said second radial magnetic coil 36B is wound around the magnetic yoke 37B.

[0161] A control unit of the ventricular assist device comprises a plurality of control sub-units 35B, wherein each of the second bearing segments 33B is provided with one of said control sub-units 35B. Each control sub-unit 35B is configured to control a current supplied to the respective second radial magnetic coil 36B of the respective second bearing segment 33B to adjustably generate a magnetic force on the second magnetisable element 191B to adjust the radial position of the second magnetisable element 191B relative to the second radial magnetic bearing 31B. Each control sub-unit 35B is in particular implemented on a printed circuit board, and provided with a control unit cover 34B. Each control unit cover 34B is in particular configured to seal the corresponding control sub-unit 35B from a fluid to be pumped by the ventricular assist device 1.

[0162] Furthermore, the four second bearing segments 33B are substantially identically constructed, and substantially equally spaced in a circumferential direction around the longitudinal axis and/or the central axis.

[0163] Additionally, the second radial sensor unit comprises a second radial Hall sensor arrangement configured to determine the radial position of the second end section 19B. In particular, the second radial Hall sensor arrangement comprises a second permanent magnet 193B fixed to the second end section 19B, specifically fixed to the second non-magnetisable element 192B of the second end section 19B, and at least one second radial Hall sensor 38B arranged adjacent the second permanent magnet 1936 in a radial direction relative to the longitudinal axis and/or the central axis in the operational state of the ventricular assist device 1. Said second permanent magnet 193B fixed to the second non-magnetisable element 192B of the second end section 19B is not shown in FIG. 4C, but will be further explained with respect to FIG. 9. The second radial Hall sensor arrangement comprises four second radial Hall sensors 38B, wherein the four second radial Hall sensors 38B are equally spaced in a circumferential direction around the longitudinal axis and/or the central axis in the operational state of the ventricular assist device 1. Specifically, each second radial Hall sensor 38B is arranged adjacent to one of the second bearing segments 33B.

[0164] The second radial Hall sensor arrangement may further be shielded from the second radial magnetic bearing 31B by one or more shielding elements arranged between the second radial Hall sensor arrangement and the second radial magnetic bearing 31B. In particular, each second radial Hall sensor 38B may be shielded from the respective adjacent second bearing segment 33B by one or more shielding elements.

[0165] The second active magnetic bearing 30B may further also comprise a structural segment ring 60. The segment ring 60 may be formed for example from a non-magnetisable material. Furthermore, each of the second bearing segments 33B are fixedly connected to the segment ring 60. Furthermore, each of the one or more control unit covers 34B and/or the respective control sub-units 35B may also be fixedly connected to the segment ring 60. Finally, the one or more second radial Hall sensors 38B may also be mounted on said segment ring 60. The segment ring 60 therefore acts as a mounting platform for components of the second active magnetic bearing 30B, and may further be fixedly connected to the drive unit 20.

[0166] FIG. 5 shows an organ of balance 50 of a pectinid. Specifically, said organ of balance 50 served as the inspiration for the first radial sensor and the second radial sensor.

[0167] In particular, the organ of balance 50 of the pectinid comprises a fluid-filled central cavity 52, wherein a movable otolith 54 is arranged. The inner surface of the central cavity 52 is further lined with hair-like receptors 51, wherein each hair-like receptor 51 is connected to at least one receptor cell 53 of the cavity wall. As the otolith 54 changes position within the central cavity 52, the otolith 54 comes into contact with one or more of said hair-like receptors 51, which consequently generate a neural signal. The neural signals are transmitted over the receptor cells 53 and thereto connected neural pathways 55. Said neural signals are subsequently evaluated by a neural network.

[0168] Analogous to this, the first radial sensor may, for example, rely on a measured change in capacitance between the first magnetisable element 191A and a respective first bearing segment 33A, caused by a movement of the rotor shaft 10 with respect to the first radial sensor. Based on the measured change in capacitance, the first radial sensor consequently determines the position of the first end section 19A and/or the first magnetisable element 191A relative to the first radial magnetic bearing 31A.

[0169] FIG. 6 shows a schematic view of a first radial sensor unit of the ventricular assist device 1, wherein the first radial magnetic bearing 31A is implemented as an exemplary homopolar magnetic bearing in the shown embodiment.

[0170] In particular, the first radial sensor unit may comprise a first radial sensor configured to measure a capacitance between each of the first bearing segments 33A and the first end section 19A, specifically the first magnetisable element 191A. FIG. 6 shows two of the four first bearing segments 33A of the first radial magnetic bearing 31A. Each first bearing segment 33A comprises a first magnetic coil 36A and a magnetic yoke 37A, wherein the first magnetic coil 36A is wound around the magnetic yoke 37A. Furthermore, the magnetic yoke 37A is separated into two equal halves, wherein said equal halves are separated from one another by an insulating plate 39A.

[0171] In particular, the first radial sensor may be configured to measure an absolute value of the capacitance between each of the first bearing segments 33A and the first magnetisable element 191A and/or a change of capacitance between each of the first bearing segments 33A and the first magnetisable element 191A. Furthermore, the first radial sensor is configured to determine the radial position of the first magnetisable element 191A based on the measured capacitance between each of the first bearing segments 33A and the first magnetisable element 191A.

[0172] In particular, the rotor shaft 10 is not fixedly connected to the first radial magnetic bearing 31A and can therefore move in relation to the first radial magnetic bearing 31A during operation of the ventricular assist device 1. Specifically, such movement may cause the rotor shaft 10, in particular the first magnetisable element 191A, to move closer to one or more first bearing segments 33A of the four first bearing segments 33A, while moving away from one or more other first bearing segments 33A of the four first bearing segments 33A. In particular, a change in the relative distances between the first magnetisable element 191A and any of the first bearing segments 33A causes a change in the capacitance between the first magnetisable element 191A and the respective first bearing segment 33A. Specifically, the capacitance may be measured between the two halves of the magnetic yoke 37A, i.e. at measuring points C1 and C2. Therefore, by measuring the capacitance at measuring points C1 and C2 (and the other two corresponding measuring points of the two other first bearing segments not shown) it is possible to determine the distance and/or a change in distance between each of the first bearing segments 33A and the first magnetisable element 191A. Based on the determined distance and/or the determined change in distance between each of the first bearing segments 33A and the first magnetisable element 191A, it is therefore possible to accurately derive the radial position of the first magnetisable element 191A relative to the first radial magnetic bearing 31A.

[0173] Therefore, the first radial sensor provides four measuring points for the capacitance, while the second radial sensor may provide an additional four measuring points. The equations for determining the radial position of the rotor shaft are therefore an over-constrained system, which allows for an increased accuracy in the determination of said radial position.

[0174] FIG. 7 shows a schematic view of a first radial sensor unit of the ventricular assist device 1, wherein the first radial magnetic bearing 31A is implemented as an exemplary heteropolar magnetic bearing in the shown embodiment, and a corresponding schematic capacitor map.

[0175] In particular, the first radial sensor unit may comprise a first radial sensor configured to measure a capacitance between each of the first bearing segments 33A and the first end section 19A, specifically the first magnetisable element 191A. FIG. 7 shows all four of the first bearing segments 33A of the first radial magnetic bearing 31A. Each first bearing segment 33A comprises a first magnetic coil 36A and a magnetic yoke 37A, wherein the first magnetic coil 36A is wound around the magnetic yoke 37A. Furthermore, each magnetic yoke 37A is separated from and insulated against its respectively neighbouring magnetic yokes 37A by four insulating plates 39A (not shown in FIG. 7 for simplicity).

[0176] In particular, the first radial sensor may be configured to measure an absolute value of the capacitance between each of the first bearing segments 33A and the first magnetisable element 191A and/or a change of capacitance between each of the first bearing segments 33A and the first magnetisable element 191A. Furthermore, the first radial sensor is configured to determine the radial position of the first magnetisable element 191A based on the measured capacitance between each of the first bearing segments 33A and the first magnetisable element 191A. Specifically, the four magnetic yokes 37A are fixedly arranged in relation to one another, and are furthermore electrically insulated against one another. Therefore, in the shown embodiment, each two neighbouring magnetic yokes 37A form a first non-variable capacitor CN1 and a second non-variable capacitor CN2, forming a combined non-variable capacitor CN. In particular, the capacitance of the first non-variable capacitor CN1 and the second non-variable capacitor CN2 does not change with the movement of the rotor shaft 10 and/or the first magnetisable element 191A. In particular, insulating plates 39A may be arranged within each of the first non-variable capacitors CN1 and/or within each of the second non-variable capacitors CN2.

[0177] In particular, the rotor shaft 10 is not fixedly connected to the first radial magnetic bearing 31A and can therefore move in relation to the first radial magnetic bearing 31A during operation of the ventricular assist device 1. Specifically, such movement may cause the rotor shaft 10, in particular the first magnetisable element 191A, to move closer to one or more first bearing segments 33A of the four first bearing segments 33A, while moving away from one or more other first bearing segments 33A of the four first bearing segments 33A. In particular, a change in the relative distances between the first magnetisable element 191A and any of the first bearing segments 33A causes a change in the capacitance between the first magnetisable element 191A and the respective first bearing segment 33A. In other words, each of the magnetic yokes 37A and the first magnetisable element 191A form a variable capacitor CV. Therefore, by measuring the capacitance across each of the variable capacitor CV, it is possible to determine the distance and/or a change in distance between each of the first bearing segments 33A and the first magnetisable element 191A. Based on the determined distance and/or the determined change in distance between each of the first bearing segments 33A and the first magnetisable element 191A, it is therefore possible to accurately derive the radial position of the first magnetisable element 191A relative to the first radial magnetic bearing 31A.

[0178] FIG. 8 shows a cross-sectional view of a ventricular assist device 1, wherein the drive unit 20 has been removed from said ventricular assist device 1. With respect to components already discussed above, reference is made to the corresponding description sections.

[0179] The first axial magnetic bearing 32A comprises a first axial magnetic coil 32A1. The first axial magnetic coil 32A1 is arranged adjacent the first magnetisable disk 16. The first axial magnetic coil 32A1 is wound around the longitudinal axis and/or the central axis in the operational state, wherein the first axial magnetic coil 32A1 is fixedly connected to the first active magnetic bearing 30A. In particular, the first axial magnetic coil 32A1 is configured such that the rotor shaft 10, and in particular the non-magnetisable section 190 is rotatable with respect to the first axial magnetic coil 32A1. The control unit, preferentially at least one of the control sub-units 35A, may be configured to control a current to the first axial magnetic coil 32A1 to adjustably generate a magnetic force on the rotor shaft 10 via the first magnetisable disk 16 to adjust the axial position of the rotor shaft 10 along the longitudinal axis and/or the central axis, preferentially based on the determined axial position of the rotor shaft 10.

[0180] The first axial magnetic bearing 32A further comprises a first magnetic pot 32A2. The first magnetic pot 32A2 may be formed from any magnetisable material. The first magnetic pot 32A2 is configured to contain and/or surround the first axial magnetic coil 32A1, wherein the first magnetic pot 32A2 is configured to be open along a surface of the first axial magnetic coil 32A1 adjacent the first magnetisable disk 16. In other words, the first axial magnetic coil 32A1 is arranged in the first magnetic pot 32A2, wherein the first magnetic pot 32A2 is configured to be open along a surface of the first axial magnetic coil 32A1 adjacent the first magnetisable disk 16. In particular, it is therefore possible to direct and/or orient a magnetic field generated by the first axial magnetic coil 32A1, thereby improving the performance of the first axial magnetic bearing 32A.

[0181] The second axial magnetic bearing 32B comprises a second axial magnetic coil 32B1. The second axial magnetic coil 32B1 is arranged adjacent the second magnetisable disk 17. The second axial magnetic coil 32B1 is wound around the longitudinal axis and/or the central axis in the operational state, wherein the second axial magnetic coil 32B1 is fixedly connected to the second active magnetic bearing 30B. In particular, the second axial magnetic coil 32B1 is configured such that the rotor shaft 10, and in particular the non-magnetisable section 190 is rotatable with respect to the second axial magnetic coil 32B1. The control unit, preferentially at least one of the control sub-units 35B, may be configured to control a current to the second axial magnetic coil 32B1 to adjustably generate a magnetic force on the rotor shaft 10 via the second magnetisable disk 17 to adjust the axial position of the rotor shaft 10 along the longitudinal axis and/or the central axis, preferentially based on the determined axial position of the rotor shaft 10.

[0182] The second axial magnetic bearing 32B further comprises a second magnetic pot 32B2. The second magnetic pot 32B2 may be formed from any magnetisable material. The second magnetic pot 32B2 is configured to contain and/or surround the second axial magnetic coil 32B1, wherein the second magnetic pot 32B2 is configured to be open along a surface of the second axial magnetic coil 32B1 adjacent the second magnetisable disk 17. In other words, the second axial magnetic coil 3261 is arranged in the second magnetic pot 3262, wherein the second magnetic pot 3262 is configured to be open along a surface of the second axial magnetic coil 3261 adjacent the second magnetisable disk 17. In particular, it is therefore possible to direct and/or orient a magnetic field generated by the second axial magnetic coil 32B1, thereby improving the performance of the second axial magnetic bearing 32B.

[0183] FIG. 9 shows a cross-sectional view of a ventricular assist device 1, as shown in FIG. 8, wherein said ventricular assist device further comprises the drive unit 20. With respect to components already discussed above, reference is made to the corresponding description sections. In particular, for reasons of clarity, reference signs are provided for some features not included in FIG. 8.

[0184] The ventricular assist device 1 comprises an axial sensor arrangement 23 (not marked in FIG. 9) configured to determine an axial position of the rotor shaft 10 along the longitudinal axis and/or the central axis in the operational state.

[0185] In particular, the axial sensor arrangement 23 comprises a ring-shaped permanent magnet 15 fixed relative to the rotor shaft 10 in a circumferential direction around the rotor shaft 10. Specifically, in the shown embodiment, the ring-shaped permanent magnet 15 is fixed to the mounting body 12, and therewith fixed to the rotor shaft 10. Furthermore, the ring-shaped permanent magnet 15 may be formed from any possible magnetic material. The ring-shaped permanent magnet 15 may be arranged along the rotor shaft 10 at a location in between the impeller 11 and the plurality of permanent drive magnets 13.

[0186] The axial sensor arrangement 23 further comprises an axial Hall sensor 23A arranged adjacent the ring-shaped permanent magnet 15 in a direction parallel to the longitudinal axis, wherein the axial Hall sensor 23A is configured to determine the axial position of the rotor shaft 10.

[0187] In particular, the axial Hall sensor 23A is fixedly connected to the drive unit 20, wherein the ventricular assist device 1 is configured such that during rotation of the impeller 11 in the operational state the ring-shaped permanent magnet 15 rotates adjacent to the axial Hall sensor 23A. Therefore, an axial movement of the rotor shaft 10 along the longitudinal axis and/or the central axis may cause a distance between the axial Hall sensor 23A and the ring-shaped permanent magnet 15 to change, which causes a change in the magnetic field measured by the axial Hall sensor 23A. Based on such a measured changed magnetic field and/or change of the magnetic field, the axial Hall sensor 23A is configured to determine the axial position of the rotor shaft 10.

[0188] The drive unit 20 comprises the magnetic motor, wherein the magnetic motor is configured to cause rotation of the impeller 11 around the longitudinal axis. In particular, the magnetic motor of the drive unit 20 comprises a plurality of magnetic coils 24, preferably six magnetic coils 24, arranged in a circumferential direction around the rotor shaft 10 in the operational state. In particular, the plurality of magnetic coils 24 are configured to produce a magnetic field to interact with the plurality of permanent drive magnets 13 to cause the rotation of the impeller 11 relative to the longitudinal axis along the rotor shaft 10. Thereby the magnetic motor is able to adjustably generate a magnetic force on the rotor shaft 10 to control a rotational speed of the impeller 11. Each of the plurality of magnetic coils may be provided in a recess in the outer body 21 of the drive unit 20, wherein each of the plurality of magnetic coils 24 is covered in the operational state by a respective access cover 22 of the drive unit. Each access cover 22 may be removably attached to the outer body 21 of the drive unit 20 to substantially seal off the respective recess.

[0189] The ventricular assist device 1 further comprises a diffusor 70 arranged adjacent the impeller 11. The diffusor 70 is in particular configured to at least partially reduce and/or remove any swirl produced in a fluid flow caused by the rotation of the impeller 11. Furthermore, the diffusor as described herein may be further configured aid in the orientation and straightening of the flow generated by the impeller.

[0190] FIG. 10 shows a FEMM (Finite Element Method Magnetics) simulation result of a magnetic field produced by an exemplary first magnetic bearing segment 33A, having a first axial magnetic coil 36A (both the upper cross-section and the lower cross-section of the first axial magnetic coil have been labelled with 36A) wound around a first magnetic yoke 37A, on a first magnetisable element 191A. For the purposes of the simulation, the first magnetic yoke 37A and the first magnetisable element 191A are simulated as being formed from magnetisable stainless steel type 1.4016. Furthermore, for the purposes of the simulation, the first axial magnetic coil 36A comprises 450 windings of copper wire having a wire thickness of 0.5 mm, wherein the first axial magnetic coil 36A has a depth of 15 mm, and wherein a current of 1 A is passed through the first axial magnetic coil 36A. Specifically, the simulation determined a net force on the first magnetisable element 191A of 22.1574 Newton along the y-direction of the coordinate system shown in FIG. 10. Furthermore, the simulation determined a net force on the first magnetic element 191A of −0.005048 Newton along the x-direction of the coordinate system shown in FIG. 10. Therefore, the exemplary first magnetic bearing segment 33A is shown to be able to generate a sufficient magnetic force on the rotor shaft 10 and/or the first magnetisable element 191A to adjust a radial position of the first magnetisable element 191A and/or the rotor shaft 10 relative to the first active magnetic bearing 30A. In particular, the exemplary first magnetic bearing segment 33A can generate said sufficient magnetic force in the y-direction, while substantially not generating a perpendicular force on the first magnetisable element 191A.

[0191] FIG. 11 shows a cross-sectional view of a fluid flow 1000 through a ventricular assist device 1, wherein only the rotor shaft 10 and the drive unit 20 are shown for simplicity. In particular, the fluid flow 1000 is herein represented by the black flow field, while inflow 1001 is schematically represented by two arrows on the left-hand side of FIG. 11 and outflow 1002 is schematically represented by two arrows on the right-hand side of FIG. 11.

[0192] Specifically, the geometry of the ventricular assist device 1 is configured such that the flow field 1000 of a fluid pumped by the ventricular assist device 1 through the ventricular assist device 1 in the operational state does not comprise any dead water zones. In particular, said dead water zones are specifically prevented in the ventricular assist device 1 due to the ventricular assist device 1 being configured to have a geometry such that the fluid pumped by the ventricular assist device 1 does not flow over any sharp edges of the ventricular assist device 1. Thereby, a shear strain on the fluid to be pumped is further significantly reduced, thus causing less damage to live particles in said fluid.

[0193] FIG. 12 shows the fluid field 1000 of FIG. 11 as a perspective, cross-sectional 3D flow body. Specifically, the consistently smooth shape of the flow field 1000 can easily be observed.

[0194] FIG. 13 shows a cross-sectional view of an exemplary ventricular assist device 1 after implantation into a lumen L of a blood vessel, such as a vein or artery. In particular, the blood vessel may for example be an aorta or pulmonary artery of a user.

[0195] In particular, the ventricular assist device 1 has been fully implanted into the lumen L of the blood vessel. Specifically, the ventricular assist device 1 has been implanted into the lumen L of the blood vessel, such that the ventricular assist device 1 is fully enclosed in said lumen L. Furthermore, the ventricular assist device 1 is configured to wirelessly and transcutaneously receive power and/or transmission signals from outside the lumen L of the blood vessel. In particular, the ventricular assist device 1 does not comprise a physical connection, such as a wire connection, through the walls W of the blood vessel.

[0196] The ventricular assist device 1 furthermore comprises two exemplary attachment grooves 41 on an outer surface of the ventricular assist device 1. Each of the two attachment grooves 41 extends fully around the ventricular assist device 1 in a circumferential direction relative to the central axis. However, the invention is not to be restricted to such a number of possible attachment grooves 41. In particular, the ventricular assist device 1 may comprise one, two, or more attachment grooves 41, wherein the number of attachment grooves 41 may be adapted to specific requirements for the ventricular assist device 1, such as a shape and/or wall thickness of the lumen in which the ventricular assist device 1 is to be implanted.

[0197] FIG. 13 further shows two fixing elements 40, wherein said fixing elements 40 may each be a wire or tie. In particular, the two fixing elements 40 are configured to at least partially compress the wall W of the blood vessel between the ventricular assist device 1 and the respective fixing element 40. Specifically, each of the two fixing elements 40 is arranged adjacent to one of the two attachment grooves 41, such that the two fixing elements 40 are configured to at least partially compress the wall W of the blood vessel in the respective attachment groove 41 of the ventricular assist device 1, thereby preventing the ventricular assist device 1 from moving along the lumen L of the blood vessel.

[0198] FIG. 14 shows a perspective view of an exemplary impeller 11 of the ventricular assist device 1 having an exemplary impeller geometry. Specifically, for illustrative purposes, the impeller 11 of FIG. 14 is shown separate from the rotor shaft 10.

[0199] In particular, the impeller 11 may be formed on or connected to the rotor shaft 10. The impeller 11 may comprise a plurality of first impeller vanes 11A at a first end of the impeller 11. The plurality of first impeller vanes 11A may in particular be configured such that during rotation of the impeller 11 (in the shown example in the clockwise direction when viewed from the first end of the impeller 11) a fluid, in which the impeller 11 is placed, is pumped from the first end of the impeller 11 towards a second end of the impeller 11.

[0200] Furthermore, FIG. 14 shows a perspective view of an exemplary diffusor 70 having an exemplary diffusor geometry, wherein the diffusor 70 may be arranged adjacent the impeller 11. In particular, the diffusor 70 may be formed around the rotor shaft 10, wherein the diffusor 70 may be configured to be static with respect to the rotor shaft 10 and the impeller 11. In particular, the diffusor 10 may be fixedly connected to the drive unit 20 and/or one or more components of the drive unit 20. In other words, the diffusor 70 may be configured to be static relative to the impeller 11 even during rotation of the impeller 11. Therefore, in particular, the exemplary diffusor 70 may be physically separate from the exemplary impeller 11. Furthermore, the diffusor 70 may be formed around the rotor shaft 10, wherein the diffusor 70 may comprise a base body 72, wherein the base body 72 may be configured to have a substantially hollow cylindrical shape. In particular, in an operational state of the ventricular assist device 1 the rotor shaft 10 may be at least partially arranged within the base body 72. In particular, the base body 72 may further be configured such that a fluid pumped by the impeller 11 is prevented from coming into direct, physical contact with the rotor shaft 10 at least while flowing through the diffusor 70.

[0201] The exemplary diffusor 70 may comprise one or more stator vanes 71. The exemplary geometry of the diffusor 70 and/or a geometry of the stator vanes 71 may in particular be configured to at least partially reduce and/or minimize swirl and/or turbulent flow produced in a fluid flow caused by the rotation of the impeller 11. Furthermore, the exemplary geometry of the diffusor 70 and/or a geometry of the stator vanes 71 may be configured to cause a lowest possible total pressure loss and/or a highest possible static pressure gain of a fluid pumped by the ventricular assist device 1. The one or more stator vanes 71 may be fixedly connected to the base body 72.

[0202] Furthermore, in the shown embodiment, a number of stator vanes 71 is different from a number of impeller vanes 11A. Specifically, in the shown example, the number of stator vanes 71 is seven and the number of impeller vanes 11A is six. However, the invention is not to be restricted to such a ratio. In particular, the number of stator vanes 71 may be larger or smaller than the number of impeller vanes 11A.

[0203] Furthermore, the number of stator vanes 71 may be identical to the number of impeller vanes 11A.

[0204] The shown impeller geometry and the shown diffusor geometry is to be understood as exemplary. Specifically, a plurality of different impeller and diffusor geometries may be implemented.

[0205] FIG. 15 shows a coordinate system highlighting a difference between an ideal permanent magnet and a commonly produced permanent magnet.

[0206] In particular, for the shown example, both the ideal permanent magnet and the commonly produced permanent magnet are cylindrically shaped. However, for clarity of the figure, neither one of the magnets is shown in FIG. 15. Furthermore, both the ideal permanent magnet and the commonly produced permanent magnet are centred on the origin of the shown coordinate system, such that an axis of both the ideal permanent magnet and the commonly produced permanent magnet is perpendicular to the coordinate axes shown.

[0207] In particular, the ideal permanent magnet produces a magnetic field that is circular symmetric around the axis of the shown ideal permanent magnet, as represented by the dashed circular trace T1. However, commonly produced permanent magnets often contain one or more defects, which cause a distortion of a magnetic field generated by the commonly produced permanent magnet, as represented by the solid trace T2, when compared to the magnetic field generated by the ideal permanent magnet.

[0208] When such a commonly produced permanent magnet is used as a sensor magnet, for example in combination with a Hall sensor, such distortions may result in errors in the measurement signal of the respective sensor. However, this may be addressed by using calibration data, as discussed above, wherein the calibration data may comprise a shape and/or strength of the magnetic field of the commonly produced permanent magnet. The respective sensor may in particular be configured to use the calibration data to account for and thereby compensate possible distortions of the magnetic field.

[0209] The embodiments described herein and/or shown in the appended Figures are not to be interpreted as limiting the scope of the invention. Therefore, for example, a ventricular assist device may comprise any combination of features described herein and/or shown in the appended Figures.

LIST OF REFERENCE NUMERALS

[0210] 1 Ventricular assist device [0211] 10 Rotor shaft [0212] 11 Impeller [0213] 11A Impeller vanes [0214] 12 Mounting body [0215] 13 Permanent drive magnet [0216] 14 Bracket [0217] 15 Ring-shaped permanent magnet [0218] 16 First magnetisable disk [0219] 17 Second magnetisable disk [0220] 19A First end section [0221] 19B Second end section [0222] 190 Non-magnetisable section [0223] 191A First magnetisable element [0224] 191B Second magnetisable element [0225] 192A First non-magnetisable element [0226] 192B Second non-magnetisable element [0227] 193A First permanent magnet [0228] 193B Second permanent magnet [0229] 20 Drive unit [0230] 21 Outer body [0231] 22 Access cover [0232] 23 Axial sensor arrangement [0233] 23A Axial Hall sensor [0234] 24 Plurality of magnetic coils [0235] 30A First active magnetic bearing [0236] 30B Second active magnetic bearing [0237] 31A First radial magnetic bearing [0238] 31B Second radial magnetic bearing [0239] 32A First axial magnetic bearing [0240] 32B Second axial magnetic bearing [0241] 32A1 First axial magnetic coil [0242] 32B1 Second axial magnetic coil [0243] 32A2 First magnetic pot [0244] 32B2 Second magnetic pot [0245] 33A First bearing segment [0246] 33B Second bearing segment [0247] 34A, 34B Control unit cover [0248] 35A Control sub-unit [0249] 36A First radial magnetic coil [0250] 36B Second radial magnetic coil [0251] 37A, 37B Magnetic yoke [0252] 38A First radial Hall sensor [0253] 38B Second radial Hall sensor [0254] 40 Fixing elements [0255] 41 Attachment grooves [0256] 50 Organ of balance [0257] 51 Hair-like receptor [0258] 52 Central cavity [0259] 53 Receptor cell [0260] 54 Otolith [0261] 55 Neural pathway [0262] 60 Structural segment ring [0263] 70 Diffusor [0264] 71 Stator vanes [0265] 72 Hollow cylindrical base body [0266] 1000 Fluid flow [0267] 1001 Inflow [0268] 1002 Outflow [0269] C1, C2 Measuring point [0270] CN, CN1, CN2 Non-variable capacitor [0271] CV Variable capacitor [0272] L Lumen [0273] T1, T2 Trace [0274] W Wall