Blood pump for reducing thrombosis

Abstract

A bearing assembly configured to retain a distal end of an impeller of a blood pump, where the impeller includes a drive shaft. The bearing assembly includes a pivot member coupled to a distal end of the drive shaft, a distal bearing cup having a proximally facing surface configured to engage at least a portion of a distal section of the pivot member, and a sleeve bearing coupled to the distal end of the drive shaft. The sleeve bearing is disposed about at least a portion of a proximal section of the pivot member.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims priority to Provisional Application No. 62 / 910,108 filed on October 3, 2019, which is incorporated herein by reference in its entirety. Background Art

[0002] Circulatory support is provided by circulatory support devices, such as blood pumps. Areas of stagnant blood in and around the bearings, particularly due to gaps between components of the blood pumps, are susceptible to thrombosis. Summary of the invention

[0003] In Example 1, a bearing assembly is provided, the bearing assembly being configured to hold the distal end of an impeller of a blood pump, the impeller having a drive shaft, and the bearing assembly comprising: a pivot member, a distal bearing cup, and a sleeve bearing, the pivot member being coupled to the distal end of the drive shaft, the distal bearing cup having a proximally facing surface configured to engage at least a portion of a distal segment of the pivot member, the sleeve bearing being disposed around at least a portion of a proximal segment of the pivot member.

[0004] In Example 2, according to the bearing assembly of Example 1, the sleeve bearing is disposed between an outer side surface of the proximal section of the pivot member and an inner side surface of the impeller.

[0005] In Example 3, according to Example 1 or 2, the bearing assembly, wherein the impeller is fixed to the drive shaft and is configured to rotate with the drive shaft about the sleeve bearing.

[0006] In Example 4, the bearing assembly of any of Examples 1 to 3 further includes a silicone damper disposed around a further portion of the proximal segment of the pivot member.

[0007] In Example 5, a bearing assembly is provided according to Example 4, wherein the proximal segment of the pivot member includes a cylindrical surface extending from the proximal end of the pivot member to the distal end of the proximal segment of the pivot member, and wherein the distal segment of the pivot member includes a first surface and a second surface, the first surface facing in a proximal direction and oriented to be at least approximately perpendicular to the cylindrical surface, and the second surface at least partially facing in a distal direction and curved to correspond to the curvature of the distal bearing cup.

[0008] In Example 6, a bearing assembly is provided according to Example 5, wherein the silicone damper includes: a proximal segment having a cylindrical inner surface configured to engage a portion of the cylindrical surface of the pivot member; and a distal segment having a distally-facing inner surface configured to engage the first surface of the distal segment of the pivot member.

[0009] In Example 7, according to Example 6, the bearing assembly, the distal section of the silicone damper includes a proximally facing outer surface, the proximally facing outer surface is configured to engage a distal edge of the impeller.

[0010] In Example 8, a bearing assembly according to any one of Examples 1 to 7, wherein the portion of the distal segment of the pivot member that is configured to engage with the proximal-facing surface of the distal bearing cup is configured to engage with the entire proximal-facing surface of the distal bearing cup.

[0011] In Example 9, a blood pump includes: an impeller, a drive shaft, a motor and a distal bearing assembly; the drive shaft is at least partially disposed in the impeller; the motor is configured to drive the impeller; the distal bearing assembly is disposed adjacent to the motor and configured to receive the distal end of the impeller, the distal bearing assembly includes: a pivot member, a distal bearing cup and a sleeve bearing, the pivot member is connected to the distal end of the drive shaft, the distal bearing cup has a proximally facing surface configured to engage at least a portion of the distal section of the pivot member, and the sleeve bearing is disposed around at least a portion of the proximal section of the pivot member.

[0012] In Example 10, the blood pump according to Example 9 further includes: a proximal bearing assembly, an impeller bearing surface and a rotor; the proximal bearing assembly is configured to hold the proximal end of the impeller of the blood pump; the proximal bearing assembly includes: a thrust plate having a distally facing surface; the impeller bearing surface is configured to engage the entire distally facing surface; the rotor is fixed to the proximal end of the impeller; wherein the motor is configured to magnetically drive the rotor, the rotor includes a cylindrical magnetic rotor having an outer surface, the outer surface is located at a first radial distance from the central axis of the drive shaft, and wherein the impeller bearing surface extends away from the central axis to a second radial distance, wherein the second radial distance is greater than or equal to the first radial distance.

[0013] In Example 11, a blood pump according to Example 9 or 10, wherein the sleeve bearing is disposed between the outer surface of the proximal section of the pivot member and the inner surface of the impeller, and wherein the impeller is fixed to the drive shaft and is configured to rotate around the sleeve bearing together with the drive shaft.

[0014] In Example 12, according to the blood pump of any of Examples 9 to 11, the distal bearing assembly further includes a silicone damper disposed around a further portion of the proximal segment of the pivot member.

[0015] In Example 13, a blood pump is provided according to Example 12, wherein the proximal segment of the pivot member includes a cylindrical surface extending from the proximal end of the pivot member to the distal end of the proximal segment of the pivot member, and wherein the distal segment of the pivot member includes a first surface and a second surface, the first surface facing in a proximal direction and oriented to be at least approximately perpendicular to the cylindrical surface, and the second surface at least partially facing in a distal direction and curved to correspond to the curvature of the distal bearing cup.

[0016] In Example 14, a blood pump according to Example 13 is provided, wherein the silicone damper comprises: a proximal segment having a cylindrical inner surface configured to engage a portion of the cylindrical surface of the pivot member; and a distal segment having a distally facing inner surface configured to engage the first surface of the distal segment of the pivot member and a proximally facing outer surface configured to engage a distal edge of the impeller.

[0017] In Example 15, a blood pump according to any one of Examples 9 to 14, wherein the portion of the distal segment of the pivot member that is configured to engage with the proximally facing surface of the distal bearing cup is configured to engage with the entire proximally facing surface of the distal bearing cup.

[0018] In Example 16, a bearing assembly is provided, the bearing assembly being configured to hold the distal end of an impeller of a blood pump, the impeller having a drive shaft, and the bearing assembly comprising: a pivot member, a distal bearing cup, and a sleeve bearing, the pivot member being connected to the distal end of the drive shaft, the distal bearing cup having a proximally facing surface configured to engage at least a portion of a distal segment of the pivot member, and the sleeve bearing being disposed around at least a portion of a proximal segment of the pivot member.

[0019] In Example 17, according to Example 16, the bearing assembly, wherein the sleeve bearing is disposed between an outer side surface of the proximal section of the pivot member and an inner side surface of the impeller.

[0020] In Example 18, according to Example 16, the bearing assembly, wherein the impeller is fixed to the drive shaft and is configured to rotate with the drive shaft about the sleeve bearing.

[0021] In Example 19, the bearing assembly of Example 16 further includes a silicone damper disposed around a further portion of the proximal segment of the pivot member.

[0022] In Example 20, a bearing assembly is provided according to Example 19, wherein the proximal segment of the pivot member includes a cylindrical surface extending from the proximal end of the pivot member to the distal end of the proximal segment of the pivot member, and wherein the distal segment of the pivot member includes a first surface and a second surface, the first surface facing in a proximal direction and oriented to be at least approximately perpendicular to the cylindrical surface, and the second surface at least partially facing in a distal direction and curved to correspond to the curvature of the distal bearing cup.

[0023] In Example 21, a bearing assembly is provided according to Example 20, wherein the silicone damper includes: a proximal segment having a cylindrical inner surface configured to engage a portion of the cylindrical surface of the pivot member; and a distal segment having a distally-facing inner surface configured to engage the first surface of the distal segment of the pivot member.

[0024] In Example 22, the bearing assembly of Example 21, wherein the distal segment of the silicone damper includes a proximally facing outer surface, the proximally facing outer surface being configured to engage a distal edge of the impeller.

[0025] In Example 23, a bearing assembly is described in accordance with Example 16, wherein the portion of the distal segment of the pivot member that is configured to engage with the proximally facing surface of the distal bearing cup is configured to engage with the entire proximally facing surface of the distal bearing cup.

[0026] In Example 24, a blood pump comprises: an impeller, a drive shaft, a motor and a distal bearing assembly; the drive shaft is at least partially disposed in the impeller; the motor is configured to drive the impeller; the distal bearing assembly is disposed adjacent to the motor and configured to receive the distal end of the impeller, the distal bearing assembly comprising: a pivot member, a distal bearing cup and a sleeve bearing, the pivot member is connected to the distal end of the drive shaft, the distal bearing cup has a proximally facing surface configured to engage at least a portion of the distal section of the pivot member, and the sleeve bearing is disposed around at least a portion of the proximal section of the pivot member.

[0027] In Example 25, the blood pump according to Example 24 further includes: a proximal bearing assembly, an impeller bearing surface and a rotor; the proximal bearing assembly is configured to hold the proximal end of the impeller of the blood pump; the proximal bearing assembly includes: a thrust plate having a distally facing surface; the impeller bearing surface is configured to engage the entire distally facing surface; the rotor is fixed to the proximal end of the impeller; wherein the motor is configured to magnetically drive the rotor, the rotor includes a cylindrical magnetic rotor having an outer surface, the outer surface is located at a first radial distance from the central axis of the drive shaft, and wherein the impeller bearing surface extends away from the central axis to a second radial distance, wherein the second radial distance is greater than or equal to the first radial distance.

[0028] In Example 26, the blood pump of Example 24, wherein the sleeve bearing is disposed between an outer side surface of the proximal section of the pivot member and an inner side surface of the impeller.

[0029] In Example 27, according to Example 24, the blood pump, wherein the impeller is fixed to the drive shaft and is configured to rotate with the drive shaft about the sleeve bearing.

[0030] In Example 28, according to the blood pump of Example 24, the distal bearing assembly further includes a silicone damper disposed around a further portion of the proximal segment of the pivot member.

[0031] In Example 29, a blood pump is provided according to Example 28, wherein the proximal segment of the pivot member includes a cylindrical surface extending from the proximal end of the pivot member to the distal end of the proximal segment of the pivot member, and wherein the distal segment of the pivot member includes a first surface and a second surface, the first surface facing in a proximal direction and oriented at least approximately perpendicular to the cylindrical surface, and the second surface at least partially facing in a distal direction and curved to correspond to the curvature of the distal bearing cup.

[0032] In Example 30, a blood pump is provided according to Example 29, wherein the silicone damper comprises: a proximal segment having a cylindrical inner surface configured to engage a portion of the cylindrical surface of the pivot member; and a distal segment having a distal-facing inner surface configured to engage the first surface of the distal segment of the pivot member.

[0033] In Example 31, the blood pump of Example 30, wherein the distal section of the silicone damper includes a proximally facing outer surface, the proximally facing outer surface being configured to engage a distal edge of the impeller.

[0034] In Example 32, a blood pump according to Example 24, wherein the portion of the distal segment of the pivot member that is configured to engage with the proximally facing surface of the distal bearing cup is configured to engage with the entire proximally facing surface of the distal bearing cup.

[0035] In Example 33, a blood pump includes: an impeller; a drive shaft, the drive shaft being at least partially disposed within the impeller; a rotor, the rotor being fixed to the proximal end of the impeller, the rotor including a cylindrical magnetic rotor having an outer surface, the outer surface being located at a first radial distance from the central axis of the drive shaft; a motor, the motor being configured to drive the impeller, wherein the motor includes a stator configured to magnetically drive the rotor; a distal bearing assembly, the distal bearing assembly being disposed adjacent to the motor and configured to receive the distal end of the impeller, the distal bearing assembly including: a pivot member coupled to the distal end of the drive shaft; a distal bearing cup, The distal bearing cup has a proximally facing surface configured to engage at least a portion of the distal section of the pivot member; and a sleeve bearing, which is arranged around at least a portion of the proximal section of the pivot member; and a proximal bearing assembly, which is configured to hold the proximal end of the impeller of the blood pump, the proximal bearing assembly comprising: a thrust plate having a distally facing surface; and an impeller bearing surface, which is configured to engage the entire distally facing surface; wherein the impeller bearing surface extends away from the central axis of the drive shaft to a second radial distance, wherein the second radial distance is greater than or equal to the first radial distance.

[0036] In Example 34, the blood pump of Example 33 further includes a silicone damper disposed around a further portion of the proximal segment of the pivot member.

[0037] In Example 35, a blood pump according to Example 33, wherein the portion of the distal segment of the pivot member that is configured to engage with the proximally facing surface of the distal bearing cup is configured to engage with the entire proximally facing surface of the distal bearing cup.

[0038] Although multiple embodiments are disclosed, other embodiments of the presently disclosed subject matter will be apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosed subject matter. Accordingly, the drawings and detailed description are to be regarded as illustrative rather than restrictive. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1A partially transparent side view of a portion of an illustrative mechanical circulatory support device (also interchangeably referred to herein as a "blood pump") is shown in accordance with an embodiment of the subject matter disclosed herein;

[0040] Figure 2 According to the embodiments of the subject matter disclosed herein, Figure 1 A side cross-sectional view of a circulatory support device is shown;

[0041] Figure 3 and Figure 4 According to the embodiments of the subject matter disclosed herein, Figure 2 An enlarged view of a portion of a side cross-sectional view of a circulatory support device is shown.

[0042] Although the disclosed subject matter is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and described in detail below. However, the goal is not to limit the subject matter disclosed herein to the specific embodiments described. On the contrary, the disclosure is intended to cover all modifications, equivalents, and alternative forms that fall within the scope of the subject matter disclosed herein, and as defined by the appended claims.

[0043] As used herein with respect to numerical values ​​(e.g., terms of magnitude, measurement, and / or other degrees of qualitative and / or quantitative observation used herein with respect to characteristics (e.g., dimensions, measurements, attributes, components, etc.) of tangible things (e.g., products, inventory, etc.) and / or ranges thereof), "about" and "substantially" are used interchangeably to refer to numerical values, configurations, orientations, and / or other characteristics that are equal to (or the same as) or are reasonably close to (or the same as) the stated numerical values, configurations, orientations, and / or other characteristics; however, there may be reasonable minor differences, such as One of ordinary skill in the relevant art will understand and readily determine errors attributable to measurement errors; differences in calibration of measurement and / or manufacturing equipment; human errors in reading and / or setting measurements; adjustments made to optimize performance and / or structural parameters based on other measurements (e.g., measurements associated with other things); specific implementation scenarios; inaccurate adjustment or manipulation of things, settings and / or measurements by people, computing devices and / or machines; system tolerances; control loops; machine learning; foreseeable variations (e.g., statistically insignificant variations, chaotic variations, system and / or model instabilities, etc.); preferences, etc. DETAILED DESCRIPTION

[0044] Stagnant blood areas in and around the bearing, particularly due to gaps between components of the blood pump, are susceptible to thrombosis. Embodiments of the subject matter disclosed herein facilitate minimizing and / or completely eliminating these gaps and stagnant areas to minimize the likelihood of thrombosis. Existing bearing designs are intended to minimize part size and complexity and utilize more standard bearing geometries and sizes. The increased size of the bearing components fills these gaps / areas, eliminates blood stagnant areas, and promotes streamlined flow through the pump. The use of high temperature materials in the bearing design allows for larger geometries and increased heat generation. In an embodiment, a first distal bearing sleeve keeps the bearing shaft aligned with the pump component, and a second distal bearing sleeve made of silicone is used as both a damper and a sealing mechanism to prevent blood from entering the bearing chamber. As the terms "proximal" and "distal" are used herein, "proximal" refers to the general direction opposite to the insertion direction (i.e., the direction in which the device will travel along to leave the subject's body); however, distal refers to the general implantation direction (i.e., the direction in which the device will travel along to reach the end of the device, which is configured to be advanced into the subject's body).

[0045] According to an embodiment of the subject matter disclosed herein, Figure 1 A partial transparent view of a portion of an exemplary percutaneous mechanical circulatory support device 100 (also interchangeably referred to herein as a "blood pump") is shown, with the impeller assembly housing 108 shown as transparent; Figure 2 Shows Figure 1 A side cross-sectional view of circulatory support device 100 is shown; and Figure 3 for Figure 2 FIG. 1 is an enlarged view of a portion of a side cross-sectional view of a circulatory support device 100. Figure 1 and Figure 2 As shown, circulatory support device 100 includes a motor 102 disposed within a motor housing 104. Motor 102 is configured to drive an impeller assembly 106 to provide blood flow through device 100. Impeller assembly 106 is disposed within an impeller assembly housing 108, which includes a plurality of outlet holes 110 defined therein. According to embodiments, motor housing 104 and impeller assembly housing 108 may be integral with each other. In other embodiments, motor housing 104 and impeller assembly housing 108 may be separate components that are configured to be removably or permanently coupled together.

[0046] A controller (not shown) is operatively coupled to the motor 102 and configured to control the motor 102. In embodiments, the controller may be disposed within the motor housing 104; or in other embodiments, may be disposed outside the housing 104 (e.g., disposed in a catheter handle, a separate housing, etc.). In embodiments, the controller may include a plurality of components, one or more of which may be disposed within the housing 104. According to embodiments, the controller may be, may include, or may include one or more field programmable gate arrays (FPGAs), one or more programmable logic devices (PLDs), one or more complex PLDs (CPLDs), one or more custom application specific integrated circuits (ASICs), one or more dedicated processors (e.g., microprocessors), one or more central processing units (CPUs), software, hardware, firmware, or any combination of these and / or other components. Although the controller is referred to herein in the singular, the controller may be implemented in multiple instances, distributed across multiple computing devices, instantiated within multiple virtual machines, etc.

[0047] like Figure 2 As shown, the impeller assembly 106 includes a drive shaft 112 and an impeller 114 coupled to the drive shaft 112, wherein the drive shaft 112 is configured to rotate with the impeller 114. As shown, the drive shaft 112 is at least partially disposed within the impeller 114. In embodiments, the drive shaft 112 may be made of any number of different rigid materials, such as, for example, steel, titanium alloy, cobalt-chromium alloy, nitinol, high-strength ceramic, and the like. The impeller assembly 106 also includes an impeller rotor 116, which is fixed to a proximal end 118 of the impeller 114. The impeller rotor 116 may be additionally or alternatively coupled to the drive shaft 112. The impeller rotor 116 may be any type of magnetic rotor that can be driven by a stator 118 as part of the motor 102. In this manner, as a magnetic field is applied to the impeller rotor 116 by the stator 118 in the motor 102, the rotor 116 rotates, thereby causing the impeller 114 to rotate.

[0048] like Figure 1 and Figure 2 As shown, the impeller assembly 106 maintains its orientation by being held at the first proximal end 120 by a first (proximal) bearing assembly 122 and at the second distal end 124 by a second (distal) bearing assembly 126. According to embodiments, the proximal bearing assembly 122 and the distal bearing assembly 126 may include different types of bearings. According to embodiments, the proximal bearing assembly 122 and / or the distal bearing assembly 126 may include lubrication, while in other embodiments, one and / or the other may not include lubrication.

[0049] According to an embodiment, the proximal bearing assembly 122 may include a thrust plate 128 having a distal facing surface 130. The thrust plate 128 may be made of a mineral, such as, for example, sapphire. The design described herein may be configured such that a gap is not formed between the distal facing surface 130 and an impeller bearing surface 132 of the impeller assembly 106. The impeller bearing surface 132 of the impeller assembly 106 may be dome-shaped and curved to correspond to the distal facing surface 130. The impeller bearing surface 132 may be configured to engage the entire distal facing surface 130. In an embodiment, the impeller bearing surface 132 may be coupled to the proximal end 134 of the drive shaft 112. In an embodiment, the impeller bearing surface 132 may include a proximal surface of a magnet cover configured to be disposed at least on a proximal surface of the rotor 116. In other embodiments (e.g., in a direct drive embodiment), the impeller bearing surface 132 may include a proximal surface of the impeller 114, the rotor 116, etc.

[0050] As shown, the impeller bearing surface 132 is configured such that there is no gap between the proximal end 118 of the impeller assembly 106 and the thrust plate 128. That is, for example, the rotor may include a cylindrical magnetic rotor having an outer surface 136, the outer surface 136 being located at a first radial distance 138 from the central axis 140 of the drive shaft 112, and the impeller bearing surface 132 may extend away from the central axis 140 of the drive shaft 112 to a second radial distance 142, wherein the second radial distance 142 is greater than or equal to the first radial distance 138. Similarly, the thrust plate 128 may be configured such that the curved distally facing surface 130 extends away from the central axis 140 of the drive shaft 112 to a third radial distance 144, wherein the third radial distance 144 is greater than or equal to the second radial distance 142.

[0051] like Figure 3As shown, the distal bearing assembly 126 includes a pivot member 146, a distal bearing cup 150, the pivot member 146 is coupled to the distal end 148 of the drive shaft 112, and the distal bearing cup 150 has a proximally facing surface 152 configured to engage at least a portion of a distal segment 154 of the pivot member 146. In an embodiment, the pivot member 146 can be ceramic and the distal bearing cup can be made of a mineral, such as sapphire. A sleeve bearing 156 can be disposed around at least a portion of the proximal segment 158 ​​of the pivot member 146. As shown, for example, the proximal segment 158 ​​of the pivot member 146 can be cylindrical in shape, can be coupled to the distal end 148 of the drive shaft 112 at a proximal end 160, and terminate at the distal segment 154 at a distal end 162. The distal segment 154 of the pivot member 146 can be dome-shaped having a first proximally facing surface 164 that extends radially relative to the central axis 140 and is oriented at least approximately perpendicular to an outer cylindrical surface 166 of the proximal segment 158. A second curved surface 168 extends from an outer edge 170 of the first surface 164. The second surface 168 includes a curvature that is configured to correspond to the curvature of the proximally facing surface 152 of the distal bearing cup 150.

[0052] As shown, the sleeve bearing 156 is disposed between the outer side surface 166 of the proximal section 158 of the pivot member 146 and the inner side surface 172 of the impeller 114. The impeller 114 can be fixed to the drive shaft 112 and configured to rotate with the drive shaft 112 about the sleeve bearing 156. Figure 3 and Figure 4 As shown, the distal bearing assembly 126 also includes a silicone damper 174 disposed around an additional portion of the proximal segment 158 ​​of the pivot member 146. According to an embodiment, the silicone damper 174 includes a proximal segment 176 having a cylindrical inner surface 178 configured to engage a portion of the outer side surface 166 of the proximal segment 158 ​​of the pivot member 146. The silicone damper 174 also includes a distal segment 180 having a distally facing inner surface 182 configured to engage the first surface 164 of the distal segment 154 of the pivot member 146 and a proximally facing outer surface 184 configured to engage the distal edge 188 of the impeller 114.

[0053] According to an embodiment, silicone damper 174 is at least partially compressible to allow some compression to maintain appropriate axial loading of impeller assembly 106. In an embodiment, silicone damper 174 may also be configured to function as a seal between impeller 114 and proximal bearing 126. In an embodiment, silicone damper 174 is configured to be maintained in place using an interference fit, which may also facilitate ensuring that pivot member 146 rotates with impeller 114 while distal bearing cup 150 remains stationary.

[0054] Figures 1 to 4 The illustrated exemplary circulatory support device 100 is not intended to suggest any limitation on the scope of use and functionality of the disclosed embodiments. The exemplary circulatory support device 100 should also not be interpreted as having any dependency or requirement related to any single component or combination of components shown herein. Furthermore, in the embodiments, Figures 1 to 4 The various components shown may be integrated with each of the other components shown herein (and / or components not shown), all of which are considered to be within the scope of the present disclosure.

[0055] Various modifications and additions may be made to the discussed exemplary embodiments without departing from the scope of the present disclosure. For example, while the embodiments described above refer to specific features, the scope of the present disclosure also includes embodiments with different combinations of features and embodiments that do not include all of the described features. Therefore, the scope of the present disclosure is intended to cover all such alternatives, modifications and variations that fall within the scope of the claims, as well as all equivalents thereof.

Claims

1. A blood pump comprising: an impeller housing including a plurality of outlet openings; An impeller assembly, wherein the impeller assembly is disposed in the impeller housing, and the impeller assembly comprises: impeller; a drive shaft disposed at least partially within the impeller; and a rotor secured to a proximal end of the impeller; a motor housing coupled to the impeller housing; a motor disposed within the motor housing and configured to rotate the impeller, the motor including a stator configured to magnetically drive the rotor; A distal bearing assembly, the distal bearing assembly is located at the distal end of the impeller assembly, the distal bearing assembly comprising: a silicone member disposed at least partially within the impeller, and Bearings.

2. The blood pump of claim 1 further comprising a proximal bearing assembly located at a proximal end of the impeller assembly.

3. The blood pump according to claim 2, wherein: The proximal bearing assembly includes a thrust plate, wherein an impeller bearing surface engages a distally facing surface of the thrust plate.

4. The blood pump according to claim 3, wherein: The thrust plate is made of sapphire.

5. The blood pump according to claim 3, wherein: The impeller bearing surface is dome-shaped to correspond to the distally facing surface of the thrust plate.

6. The blood pump according to claim 1, wherein: The bearing is disposed on a distal side of the silicone member.

7. The blood pump according to claim 6, wherein: The bearing is at least partially disposed within the impeller.

8. The blood pump according to claim 1, wherein: The bearing is a sleeve bearing.

9. The blood pump according to claim 8, wherein: The impeller is fixed to the drive shaft and is configured to rotate with the drive shaft about the sleeve bearing.

10. A blood pump comprising: impeller; a drive shaft disposed at least partially within the impeller; a rotor secured to a proximal end of the impeller; an electric motor configured to rotate the impeller, the electric motor including a stator configured to magnetically drive the rotor; A distal bearing assembly, the distal bearing assembly being disposed distally relative to the impeller, the bearing assembly comprising: a silicone member disposed at least partially within the impeller, and Sapphire bearings.

11. The blood pump according to claim 10, wherein: The silicone member is axially compressible.

12. The blood pump according to claim 10, wherein: The sapphire bearing is arranged at the far side of the impeller.

13. A blood pump comprising: impeller; a drive shaft disposed at least partially within the impeller; a motor configured to drive the drive shaft and the impeller; A bearing assembly, the bearing assembly being disposed distally relative to the impeller, the bearing assembly comprising: a silicone member disposed at least partially within the impeller; Sapphire bearings; and A pivot member is disposed between the silicone member and the sapphire bearing.

14. The blood pump according to claim 13, wherein: The sapphire bearing is arranged at the far side of the impeller.

15. The blood pump according to claim 13, wherein: The silicone member is disposed between the pivot member and the drive shaft.

16. The blood pump according to claim 13, wherein: The pivot member is at least partially disposed within the impeller.

17. The blood pump according to claim 13, wherein: The silicone member is at least partially compressible.

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