Pump and method for mixed flow blood pumping

Patent metadata

Field	Value
Publication number	US-2016144089-A1
Application number	US-201514952296-A
Country	US
Kind code	A1
Filing date	Nov 25, 2015
Priority date	Nov 26, 2014
Publication date	May 26, 2016
Grant date	—

Abstract

A blood pump includes a housing and a rotor within the housing configured to rotate along an axis. The rotor may include a hub, the hub having regions with blades and regions without blades. The regions without blades may have a constant outer diameter and may extend along at least one fourth the length of the hub. The regions with blades may have an increasing outer diameter. Blades may be disposed on a downstream end region of the hub and extend downstream of the hub. Blades may begin approximately halfway along the axial length of a motor stator located about a hub and extend downstream of the motor stator. Blades may have portions that produce axial fluid flow and radial fluid flow with improved flow characteristics.

First claim

What is claimed is:

1 . A blood pump comprising:
a housing; and a rotor within the housing configured to rotate along an axis, the rotor including: a hub that has an axial length, the hub having (i) a first region where no blades are located, the first region having a constant outer diameter and extending along at least one fourth of the length of the hub, and (ii) a blade region located downstream of the first region, wherein the outer diameter of the hub increases along the blade region in a downstream direction; and blades disposed on the blade region that are configured to produce axial fluid flow in the direction of the axis and radial fluid flow in a direction radially outward from the axis.

2 . The blood pump of claim 1 , wherein each of the blades extends along between one third and two thirds of the axial length of the hub.

3 . The blood pump of claim 1 , wherein the outer diameter of the hub increases with a linear taper over the blade region.

4 . The blood pump of claim 1 , wherein the outer diameter of the hub increases over the entire blade region.

5 . The blood pump of claim 1 , wherein each of the blades wraps around approximately 170 degrees of the hub about the axis.

6 . The blood pump of claim 1 , wherein the pump includes a motor stator having an upstream region and a downstream region, the upstream region of the motor stator extending around the first region of the hub and the downstream region of the motor stator extending around the blade region of the hub.

7 . The blood pump of claim 6 , wherein the upstream region of the motor stator extends around the first region along at least a third of a length of the motor stator measured along the axis, and the downstream region of the motor stator extends around the blade region along at least a third of the length of the motor stator measured along the axis.

8 . The blood pump of claim 1 , wherein the rotor includes a downstream bearing component and the housing defines an annular volume located about the downstream bearing component, and the axis is located at an offset from the center of the annular volume.

9 . A blood pump comprising:
a hub containing magnetic material and having an axis of rotation and a generally axisymmetric shape; a motor stator located about the hub; a housing defining an inlet, an outlet, and a flow path from the inlet to the outlet; and blades located on the hub beginning approximately halfway along the axial length of the motor stator and extending downstream of the motor stator, each blade including:
an upstream portion that adds energy to fluid having forward flow primarily in the direction along the axis of the hub; and
a downstream portion that adds energy to fluid having forward flow containing a radial or centrifugal flow component.

10 . The blood pump of claim 9 , wherein the outlet is oriented off the axis of rotation of the hub.

11 . The blood pump of claim 9 , further comprising exactly one stator in the flow path, the stator being located upstream from the rotor hub.

12 . The blood pump of claim 9 , further comprising an annular volume disposed around the axis of rotation, the annular volume being located downstream from the blades along the axis of rotation and the annular volume being in fluid communication with the outlet, the annular volume having a shape that is asymmetric about the axis of rotation.

13 . The blood pump of claim 12 , wherein the housing comprises a first wall and a second wall that define the annular volume, the first wall flaring outward from the axis of rotation in a downstream direction along the axis of rotation, the second wall flaring inward toward the axis of rotation in a downstream direction along the axis of rotation.

14 . The blood pump of claim 9 , wherein each of the blades has a leading edge, and the leading edges are oriented substantially normal to a primary direction of fluid flow at the leading edges.

15 . The blood pump of claim 9 , wherein each of the blades has a trailing edge, the trailing edge being oriented substantially normal to a primary direction of fluid flow at the trailing edge.

16 . A blood pump comprising:
a hub having an axis of rotation and a generally cylindrical shape, the hub having an upstream end region, a central region, and a downstream end region, the hub including a magnetic material; and blades located at the downstream end region of the hub, the blades extending downstream of the hub, each blade including
an upstream portion that is located proximate the hub and is configured to add energy to fluid having forward flow along the axis of the hub, and
a downstream portion that is configured to add energy to the fluid having forward flow in a direction radially outward from the hub.

17 . The blood pump of claim 16 , further comprising a housing that includes a wall defining a portion of a flow path, the wall tapering inward toward the axis of rotation along a downstream direction through the flow path.

18 . The blood pump of claim 17 , wherein the wall is axially located along the axis of rotation over an aft end region of the hub and at least portions of the blades.

19 . The blood pump of claim 17 , wherein each of the blades has a leading edge, and the housing has an inner diameter located over the leading edges of the blades, the inner diameter being smaller than any inner diameter of the housing located upstream of the inner diameter along the axis of rotation.

20 . The blood pump of claim 16 , further comprising a housing defining a flow path through the blood pump,
wherein each of the blades has a leading edge, and the leading edges are oriented substantially normal to a primary direction of flow through the flow path at the leading edges.

21 . The blood pump of claim 16 , wherein the hub has a downstream end region having an outer diameter that decreases along a downstream direction of blood flow, and wherein the blades are attached to the hub in the downstream end region.

22 . The blood pump of claim 16 , further comprising a housing defining a volute, the volute having a cross-sectional area that expands in a circumferential direction about the axis of rotation, the volute having a circular or trapezoidal cross-sectional geometry in a region of the maximum cross-sectional area of the volute.

23 . The blood pump of claim 16 , further comprising a housing defining a volute, the volute having a cross-sectional area that expands in a circumferential direction about the axis of rotation,
wherein the volute has curved inner regions that are convex toward the interior of the volute, and the volute has an outer region located between the curved inner regions, the outer region having a concave curvature toward the interior of the volute.

24 . The blood pump of claim 16 , wherein the downstream end region of the hub defines one or more dimples configured to generate additional flow components.

25 . The blood pump of claim 24 , wherein the one or more dimples are configured to aid in washing a surface of the blood pump.

26 . The blood pump of claim 25 , wherein the one or more dimples are configured to aid in washing a surface of a bearing component of the blood pump.

27 . The blood pump of claim 16 , wherein the downstream end region of the hub comprises a concave outer surface that defines a recess in the hub that extends upstream along the ax

Assignees

• Thoratec Corp

Inventors

• Woo Yi-Ren
• Dur Onur
• Reichenbach Steven H

Classifications

• F04D29/2205

  Conventional flow pattern · CPC title

• F04D13/0646 Primary

  the hollow pump or motor shaft being the conduit for the working fluid · CPC title

• F04D29/047

  hydrostatic; hydrodynamic · CPC title

• F04D29/24 Primary

  Vanes · CPC title

• F04D29/588

  cooling or heating the machine (F04D29/5886, F04D29/5893 take precedence) · CPC title