Patent Description:
<CIT> discloses a blood pump comprising a mechanical bearing with a spherical segment which consists of a hard material, preferably produced by means of a chemical deposition process.

In an Example <NUM> (as claimed), a bearing assembly configured to retain a distal end of an impeller of a blood pump, the impeller having a drive shaft, and the bearing assembly comprising: 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 disposed around at least a portion of a proximal section of the pivot member.

In an Example <NUM>, the bearing assembly of Example <NUM>, wherein the sleeve bearing is disposed between an outside surface of the proximal section of the pivot member and an inside surface of the impeller.

In an Example <NUM>, the bearing assembly of either of Examples <NUM> or <NUM>, wherein the impeller is fixed to the drive shaft and configured to rotate with the drive shaft around the sleeve bearing.

In an Example <NUM>, the bearing assembly of any of Examples <NUM>-<NUM>, further comprising a silicone dampener disposed around an additional portion of the proximal section of the pivot member. In an Example <NUM>, the bearing assembly of Example <NUM>, wherein the proximal section of the pivot member comprises a cylindrical surface extending from a proximal end of the pivot member to a distal end of the proximal section of the pivot member, and wherein the distal section of the pivot member comprises a first surface facing in a
proximal direction and oriented at least approximately perpendicular to the cylindrical surface and a second surface facing at least partially in a distal direction and curved to correspond to a curvature of the distal bearing cup.

In an Example <NUM>, the bearing assembly of Example <NUM>, wherein the silicone dampener comprises: a proximal section having a cylindrical inner surface configured to engage a portion of the cylindrical surface of the pivot member; and a distal section having a distally-facing inner surface configured to engage the first surface of the distal section of the pivot member.

In an Example <NUM>, the bearing assembly of Example <NUM>, wherein the distal section of the silicone dampener comprises a proximally-facing outer surface configured to engage a distal edge of the impeller.

In an Example <NUM>, the bearing assembly of any of Examples <NUM>-<NUM>, wherein the portion of the distal section of the pivot member configured to be engaged by the proximally-facing surface of the distal bearing cup is configured to engage the entire proximally-facing surface of the distal bearing cup.

In an Example <NUM> (as claimed), a blood pump, comprising: an impeller; a drive shaft disposed at least partially within the impeller; a motor configured to drive the impeller; and a distal bearing assembly disposed adjacent the motor and configured to receive a distal end of the impeller, the distal bearing assembly comprising: 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 disposed around at least a portion of a proximal section of the pivot member.

In an Example <NUM>, the blood pump of Example <NUM>, further comprising: a proximal bearing assembly configured to retain a proximal end of the impeller of the blood pump, the proximal bearing assembly comprising: a thrust plate having a distal-facing surface; and an impeller bearing surface configured to engage the entire distal-facing surface; and a rotor fixed to the proximal end of the impeller, wherein the motor is configured to magnetically drive the rotor, the rotor comprising a cylindrical magnetic rotor having an outer surface that is located a first radial distance from a central axis of the drive shaft, and wherein the impeller bearing surface extends to a second radial distance away from the central axis, wherein the second radial distance is greater than or equal to the first radial distance.

In an Example <NUM>, the blood pump of either of Examples <NUM> or <NUM>, wherein the sleeve bearing is disposed between an outside surface of the proximal section of the pivot member and an inside surface of the impeller, and wherein the impeller is fixed to the drive shaft and configured to rotate with the drive shaft around the sleeve bearing.

In an Example <NUM>, the blood pump of any of Examples <NUM>-<NUM>, the distal bearing assembly further comprising a silicone dampener disposed around an additional portion of the proximal section of the pivot member.

In an Example <NUM>, the blood pump of Example <NUM>, wherein the proximal section of the pivot member comprises a cylindrical surface extending from a proximal end of the pivot member to a distal end of the proximal section of the pivot member, and wherein the distal section of the pivot member comprises a first surface facing in a proximal direction and oriented at least approximately perpendicular to the cylindrical surface and a second surface facing at least partially in a distal direction and curved to correspond to a curvature of the distal bearing cup.

In an Example <NUM>, the blood pump of Example <NUM>, wherein the silicone dampener comprises: a proximal section having a cylindrical inner surface configured to engage a portion of the cylindrical surface of the pivot member; and a distal section having a distally-facing inner surface configured to engage the first surface of the distal section of the pivot member and a proximally-facing outer surface configured to engage a distal edge of the impeller.

In an Example <NUM>, the blood pump of any of Examples <NUM>-<NUM>, wherein the portion of the distal section of the pivot member configured to be engaged by the proximally-facing surface of the distal bearing cup is configured to engage the entire proximally-facing surface of the distal bearing cup.

In an Example <NUM>, a bearing assembly configured to retain a distal end of an impeller of a blood pump, the impeller having a drive shaft, and the bearing assembly comprising: 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 disposed around at least a portion of a proximal section of the pivot member.

In an Example <NUM>, the bearing assembly of Example <NUM>, wherein the impeller is fixed to the drive shaft and configured to rotate with the drive shaft around the sleeve bearing.

In an Example <NUM>, the bearing assembly of Example <NUM>, further comprising a silicone dampener disposed around an additional portion of the proximal section of the pivot member.

In an Example <NUM>, the bearing assembly of Example <NUM>, wherein the proximal section of the pivot member comprises a cylindrical surface extending from a proximal end of the pivot member to a distal end of the proximal section of the pivot member, and wherein the distal section of the pivot member comprises a first surface facing in a proximal direction and oriented at least approximately perpendicular to the cylindrical surface and a second surface facing at least partially in a distal direction and curved to correspond to a curvature of the distal bearing cup.

In an Example <NUM>, the bearing assembly of Example <NUM>, wherein the portion of the distal section of the pivot member configured to be engaged by the proximally-facing surface of the distal bearing cup is configured to engage the entire proximally-facing surface of the distal bearing cup.

In an Example <NUM>, a blood pump, comprising: an impeller; a drive shaft disposed at least partially within the impeller; a motor configured to drive the impeller; and a distal bearing assembly disposed adjacent the motor and configured to receive a distal end of the impeller, the distal bearing assembly comprising: 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 disposed around at least a portion of a proximal section of the pivot member.

In an Example <NUM>, the blood pump of Example <NUM>, wherein the sleeve bearing is disposed between an outside surface of the proximal section of the pivot member and an inside surface of the impeller.

In an Example <NUM>, the blood pump of Example <NUM>, wherein the impeller is fixed to the drive shaft and configured to rotate with the drive shaft around the sleeve bearing.

In an Example <NUM>, the blood pump of Example <NUM>, the distal bearing assembly further comprising a silicone dampener disposed around an additional portion of the proximal section of the pivot member.

In an Example <NUM>, the blood pump of Example <NUM>, wherein the silicone dampener comprises: a proximal section having a cylindrical inner surface configured to engage a portion of the cylindrical surface of the pivot member; and a distal section having a distally-facing inner surface configured to engage the first surface of the distal section of the pivot member.

In an Example <NUM>, the blood pump of Example <NUM>, wherein the distal section of the silicone dampener comprises a proximally-facing outer surface configured to engage a distal edge of the impeller.

In an Example <NUM>, the blood pump of Example <NUM>, wherein the portion of the distal section of the pivot member configured to be engaged by the proximally-facing surface of the distal bearing cup is configured to engage the entire proximally-facing surface of the distal bearing cup.

In an Example <NUM>, a blood pump, comprising: an impeller; a drive shaft disposed at least partially within the impeller; a rotor fixed to a proximal end of the impeller, the rotor comprising a cylindrical magnetic rotor having an outer surface that is located a first radial distance from a central axis of the drive shaft; a motor configured to drive the impeller, wherein the motor comprises a stator configured to magnetically drive the rotor; a distal bearing assembly disposed adjacent the motor and configured to receive a distal end of the impeller, the distal bearing assembly comprising: 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 disposed around at least a portion of a proximal section of the pivot member; and a proximal bearing assembly configured to retain a 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 configured to engage the entire distally-facing surface, wherein the impeller bearing surface extends to a second radial distance away from the central axis of the drive shaft, wherein the second radial distance is greater than or equal to the first radial distance.

In an Example <NUM>, the blood pump of Example <NUM>, further comprising a silicone dampener disposed around an additional portion of the proximal section of the pivot member.

While multiple embodiments are disclosed, still other embodiments of the presently disclosed subject matter will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosed subject matter.

While 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 are described in detail below. The intention, however, is not to limit the subject matter disclosed herein to the particular embodiments described.

As used herein in association with values (e.g., terms of magnitude, measurement, and/or other degrees of qualitative and/or quantitative observations that are used herein with respect to characteristics (e.g., dimensions, measurements, attributes, components, etc.) and/or ranges thereof, of tangible things (e.g., products, inventory, etc.), "about" and "approximately" may be used, interchangeably, to refer to a value, configuration, orientation, and/or other characteristic that is equal to (or the same as) the stated value, configuration, orientation, and/or other characteristic or equal to (or the same as) a value, configuration, orientation, and/or other characteristic that is reasonably close to the stated value, configuration, orientation, and/or other characteristic, but that may differ by a reasonably small amount such as will be understood, and readily ascertained, by individuals having ordinary skill in the relevant arts to be attributable to measurement error; differences in measurement and/or manufacturing equipment calibration; human error in reading and/or setting measurements; adjustments made to optimize performance and/or structural parameters in view of other measurements (e.g., measurements associated with other things); particular implementation scenarios; imprecise adjustment and/or manipulation of things, settings, and/or measurements by a person, a computing device, and/or a machine; system tolerances; control loops; machine-learning; foreseeable variations (e.g., statistically insignificant variations, chaotic variations, system and/or model instabilities, etc.); preferences; and/or the like.

Stagnant blood areas in and around bearings, particularly due to gaps between components of the blood pump, are prone to thrombus formation. Embodiments of the subject matter disclosed herein facilitate minimizing and/or eliminating these gaps and stagnant areas altogether so as to minimize the potential of thrombus formation. Existing bearing designs aim to minimize part size and complexity and utilize a more standard bearing geometry and size. Increasing the size of bearing components fills these gaps/areas and eliminates areas of blood stagnation and promotes streamlined flow through the pump. Use of high temperature materials in the bearing design can tolerate larger geometry and increased heat generation. In embodiments, a first distal bearing sleeve keeps the bearing shaft aligned with the pump components, while a second distal bearing sleeve made of silicone acts as both a dampener 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 that of insertion - that is, the direction in which one would travel along the device to exit the subject's body; whereas distal refers to the general direction of implantation - that is, the direction in which one would travel along the device to reach the end of the device that is configured to advance into the subject's body.

<FIG> depicts a partially transparent view of a portion of an illustrative percutaneous mechanical circulatory support device <NUM> (also referred to herein, interchangeably, as a "blood pump"), in which the impeller assembly housing <NUM> is shown as transparent; <FIG> depicts a cross-sectional side view of the circulatory support device <NUM> depicted in <FIG>; and <FIG> is an enlarged view of a portion of the cross-sectional side view of the circulatory support device <NUM> depicted in <FIG>, in accordance with embodiments of the subject matter disclosed herein. As shown in <FIG> and <FIG>, the circulatory support device <NUM> includes a motor <NUM> disposed within a motor housing <NUM>. The motor <NUM> is configured to drive an impeller assembly <NUM> to provide a flow of blood through the device <NUM>. The impeller assembly <NUM> is disposed within an impeller assembly housing <NUM>, which includes a number of outlet apertures <NUM> defined therein. According to embodiments, the motor housing <NUM> and the impeller assembly housing <NUM> may be integrated with one another. In other embodiments, the motor housing <NUM> and the impeller assembly housing <NUM> may be separate components configured to be coupled together, either removeably or permanently.

A controller (not shown) is operably coupled to the motor <NUM> and is configured to control the motor <NUM>. The controller may be disposed within the motor housing <NUM> in embodiments, or, in other embodiments, may be disposed outside the housing <NUM> (e.g., in a catheter handle, independent housing, etc.). In embodiments, the controller may include multiple components, one or more of which may be disposed within the housing <NUM>. According to embodiments, the controller may be, include, or be included in 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, and/or the like.

As shown in <FIG>, the impeller assembly <NUM> includes a drive shaft <NUM> and an impeller <NUM> coupled thereto, where the drive shaft <NUM> is configured to rotate with the impeller <NUM>. As shown, the drive shaft <NUM> is at least partially disposed within the impeller <NUM>. In embodiments, the drive shaft <NUM> may be made of any number of different rigid materials such as, for example, steel, titanium alloys, cobalt chromium alloys, nitinol, high-strength ceramics, and/or the like. The impeller assembly <NUM> further includes an impeller rotor <NUM> fixed to the proximal end <NUM> of the impeller <NUM>. The impeller rotor <NUM> may additionally, or alternatively, be coupled to the drive shaft <NUM>. The impeller rotor <NUM> may be any type of magnetic rotor capable of being driven by a stator <NUM> that is part of the motor <NUM>. In this manner, as a magnetic field is applied to the impeller rotor <NUM> by the stator <NUM> in the motor <NUM>, the rotor <NUM> rotates, causing the impeller <NUM> to rotate.

As shown in <FIG> and <FIG>, the impeller assembly <NUM> is maintained in its orientation by being retained, at a first, proximal end <NUM>, by a first (proximal) bearing assembly <NUM> and, at a second, distal end <NUM>, by a second (distal) bearing assembly <NUM>. According to embodiments, the proximal bearing assembly <NUM> and the distal bearing assembly <NUM> may include different types of bearings. According to embodiments, the proximal bearing assembly <NUM> and/or the distal bearing assembly <NUM> may include lubrication, while, in other embodiments, one and/or the other may not include lubrication.

According to embodiments, the proximal bearing assembly <NUM> may include a thrust plate <NUM> having a distal-facing surface <NUM>. The thrust plate <NUM> may be made of a mineral such as, for example, sapphire. The design described herein may be configured such that no gap is formed between the distal-facing surface <NUM> and an impeller bearing surface <NUM> of the impeller assembly <NUM>. The impeller-bearing surface <NUM> of the impeller assembly <NUM> may be dome-shaped and curved to correspond to the distally-facing surface <NUM>. The impeller-bearing surface <NUM> may be configured to engage the entire distally-facing surface <NUM>. In embodiments, the impeller-bearing surface <NUM> may be coupled to a proximal end <NUM> of the drive shaft <NUM>. In embodiments, the impeller-bearing surface <NUM> may include a proximal surface of a magnet cover that is configured to be disposed over at least a proximal surface of the rotor <NUM>. In other embodiments (e.g., in direct-drive implementations), the impeller bearing surface <NUM> may include a proximal surface of the impeller <NUM>, of the rotor <NUM>, and/or the like.

As shown, the impeller bearing surface <NUM> is configured such that there is no gap between the proximal end <NUM> of the impeller assembly <NUM> and the thrust plate <NUM>. That is, for example, the rotor may include a cylindrical magnetic rotor having an outer surface <NUM> that is located a first radial distance <NUM> from a central axis <NUM> of the drive shaft <NUM>, and the impeller bearing surface <NUM> may extend to a second radial distance <NUM> away from the central axis <NUM> of the drive shaft <NUM>, where the second radial distance <NUM> is greater than or equal to the first radial distance <NUM>. Similarly, the thrust plate <NUM> may be configured such that the curved, distally-facing surface <NUM> extends to a third radial distance <NUM> away from the central axis <NUM> of the drive shaft <NUM>, where the third radial distance <NUM> is greater than or equal to the second radial distance <NUM>.

As shown in <FIG>, the distal bearing assembly <NUM> includes a pivot member <NUM> coupled to a distal end <NUM> of the drive shaft <NUM>, a distal bearing cup <NUM> having a proximally-facing surface <NUM> configured to engage at least a portion of a distal section <NUM> of the pivot member <NUM>. The pivot member <NUM> may be, in embodiments, ceramic, and the distal bearing cup may be made of a mineral such as sapphire. A sleeve bearing <NUM> is disposed around at least a portion of the proximal section <NUM> of the pivot member <NUM>. As shown, for example, the proximal section <NUM> of the pivot member <NUM> may be cylindrical in shape, coupled, at a proximal end <NUM> to the distal end <NUM> of the drive shaft <NUM> and terminating, at a distal end <NUM> in the distal section <NUM>. The distal section <NUM> of the pivot member <NUM> may be dome-shaped, having a first, proximally-facing surface <NUM> that extends radially with respect to the central axis <NUM> and is oriented at least approximately perpendicularly to an outside cylindrical surface <NUM> of the proximal section <NUM>. A second, curved, surface <NUM> extends from an outer edge <NUM> of the first surface <NUM>. The second surface <NUM> includes a curvature that is configured to correspond to a curvature of the proximally-facing surface <NUM> of the distal bearing cup <NUM>.

As shown, the sleeve bearing <NUM> is disposed between the outside surface <NUM> of the proximal section <NUM> of the pivot member <NUM> and an inside surface <NUM> of the impeller <NUM>. The impeller <NUM> may be fixed to the drive shaft <NUM> and configured to rotate with the drive shaft <NUM> around the sleeve bearing <NUM>. As is shown in <FIG> and <FIG>, the distal bearing assembly <NUM> further includes a silicone dampener <NUM> disposed around an additional portion of the proximal section <NUM> of the pivot member <NUM>. According to embodiments, the silicone dampener <NUM> includes a proximal section <NUM> having a cylindrical inner surface <NUM> configured to engage a portion of the outside surface <NUM> of the proximal section <NUM> of the pivot member <NUM>. The silicone dampener <NUM> further includes a distal section <NUM> having a distally-facing inner surface <NUM> configured to engage the first surface <NUM> of the distal section <NUM> of the pivot member <NUM>, and a proximally-facing outer surface <NUM> configured to engage a distal edge <NUM> of the impeller <NUM>.

According to embodiments, the silicone dampener <NUM> is at least partially compressible to allow some compression to maintain appropriate axial loading of the impeller assembly <NUM>. In embodiments, the silicone dampener <NUM> also may be configured to function as a seal between the impeller <NUM> and the proximal bearing <NUM>. In embodiments, the silicone dampener <NUM> is configured to be maintained in place using an interference fit, which also may facilitate ensuring that the pivot member <NUM> turns with the impeller <NUM>, while the distal bearing cup <NUM> remains stationary.

The illustrative circulatory support device <NUM> shown in <FIG> is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the present disclosure. The illustrative circulatory support device <NUM> also should not be interpreted as having any dependency or requirement related to any single component or combination of components illustrated therein. Additionally, various components depicted in <FIG> may be, in embodiments, integrated with various ones of the other components depicted therein (and/or components not illustrated), all of which are considered to be within the ambit of the present disclosure.

Claim 1:
A bearing assembly (<NUM>) configured to retain a distal end (<NUM>) of an impeller (<NUM>) of a blood pump (<NUM>), the impeller having a drive shaft (<NUM>), and the bearing assembly (<NUM>) comprising:
a pivot member (<NUM>) coupled to a distal end (<NUM>) of the drive shaft (<NUM>);
a distal bearing cup (<NUM>) having a proximally-facing surface (<NUM>) configured to engage at least a portion of a distal section (<NUM>) of the pivot member (<NUM>); and characterised by
a sleeve bearing (<NUM>) disposed around at least a portion of a proximal section (<NUM>) of the pivot member (<NUM>).