# US 10,765,788 B2 · Axial flow rotor with downstream bearing wash flow > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,765,788 B2 - Document ID: US10765788B2 - Status: Granted - Kind: B2 - Application number: 16/124,277 - Filed: 2018-09-07 - Published: 2019-01-03 - Granted: 2020-09-08 - Earliest claimed: 2015-01-06 - Assignees: HeartWare, Inc. - Applicants: HeartWare, Inc. - Inventors: Mustafa Ertan Taskin; Ellen Keysselitz; Wolfgang Kerkhoffs - Web page: https://patentgrep.com/patent/US10765788B2 ## CPC - A61M 60/824: Hydrodynamic or fluid film bearings - A61M 60/148: in line with a blood vessel using resection or like techniques, e.g. permanent endovascular heart assist devices - A61M 60/178: drawing blood from a ventricle and returning the blood to the arterial system via a cannula external to the ventricle, e.g. left or right ventricular assist devices - A61M 60/221: the blood flow through the rotating member having both radial and axial components, e.g. mixed flow pumps - A61M 60/242: with the outlet substantially perpendicular to the axis of rotation - A61M 60/416: transmitted directly by the motor rotor drive shaft - A61M 60/419: the force acting on the blood contacting member being permanent magnetic, e.g. from a rotating magnetic coupling between driving and driven magnets - A61M 60/422: the force acting on the blood contacting member being electromagnetic, e.g. using canned motor pumps - A61M 60/806: Vanes or blades - A61M 60/81: Pump housings - A61M 60/825: Contact bearings, e.g. ball-and-cup or pivot bearings - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} ## Abstract An implantable blood pump includes an impeller rotatable about a rotational axis, having a body with a bottom surface at a downstream end and a central opening centered about the axis extending at least partially through the body from the bottom surface. A projecting element, e.g., a shaft, extends from below the bottom surface into or through the opening to support the impeller. The body can be configured to drive a primary downstream blood flow along an exterior of the body to beyond a peripheral edge of the bottom surface, and to provide a secondary downstream blood flow through the opening and along the bottom surface to beyond the peripheral edge, the secondary flow improving washing of a bearing surface. ## Claims ### Claim 1 An impeller for a blood pump, comprising: a ferromagnetic body having a bottom surface at a downstream end of the body and a central opening extending at least partially through the body from the bottom surface, the central opening centered about a rotational axis of the body, the rotational axis defining an axial direction; and the body configured to rotate about an element projecting from a surface below the bottom surface into the central opening to drive a primary blood flow along an exterior of the body to beyond a peripheral edge of the bottom surface, and the body configured to drive a secondary blood flow through the central opening toward the bottom surface and then outwardly along the bottom surface to beyond the peripheral edge, the body including a bearing proximate a distal end of the element, the bottom surface undulates in a direction of a circumference of the bottom surface between troughs and respective elevations, the troughs and elevations of the bottom surface are configured to drive the secondary flow of the fluid towards the peripheral edge of the bottom surface. ### Claim 2 (depends on 1) The impeller of claim 1, wherein the undulations of the body define a plurality of ridges protruding in an axial direction below portions of the bottom surface, the ridges defining a plurality of fluid channels for driving the secondary flow between the opening and the peripheral edge. ### Claim 3 (depends on 2) The impeller of claim 2, wherein the ridges are blades elongated in a direction from the opening towards the peripheral edge. ### Claim 4 (depends on 3) The impeller of claim 3, wherein the fluid channels have arcuate shape. ### Claim 5 (depends on 3) The impeller of claim 3, wherein the ridges have straight walls defining the plurality of fluid channels. ### Claim 6 (depends on 5) The impeller of claim 5, wherein the ridges taper in a direction from the peripheral edge towards the opening. ### Claim 7 (depends on 6) The impeller of claim 6, wherein the walls of each fluid channel are parallel. ### Claim 8 (depends on 7) The impeller of claim 7, wherein each fluid channel extends in a radial direction from the opening to the peripheral edge. ### Claim 9 (depends on 1) The impeller of claim 1, wherein the impeller includes blades projecting from the exterior of the body for driving the primary flow. ### Claim 10 An implantable blood pump, comprising: a ferromagnetic impeller body having a bottom surface at a downstream end of the body and a central opening extending at least partially through the body from the bottom surface, the central opening centered about a rotational axis of the body, the rotational axis defining an axial direction; the body being configured to rotate about an element projecting from below the bottom surface into the central opening to drive a primary downstream blood flow along an exterior of the body to beyond a peripheral edge of the bottom surface and axially downstream from the impeller, the body including a bearing proximate a distal end of the element; the body configured to drive a secondary downstream blood flow through the central opening toward the bottom surface and then outwardly along the bottom surface to beyond the peripheral edge, the bottom surface include a plurality of axially protruding ridges defining at least one fluid channel, the plurality of axially protruding ridges being configured to drive the secondary downstream blood flow from the opening towards the peripheral edge; and the pump being configured to rotate the body about the axis and to drive the blood in a generally axial direction downstream from the impeller. ### Claim 11 (depends on 10) The pump of claim 10, wherein each one of the plurality of axially protruding ridges is a blade elongated in a direction from the opening towards the peripheral edge, and the plurality of fluid channels have an arcuate shape. ### Claim 12 (depends on 10) The pump of claim 10, wherein each one of the plurality of axially protruding ridge has straight walls defining the at least one fluid channel, the straight walls extending in a radial direction from the opening to the peripheral edge. ### Claim 13 (depends on 10) The pump of claim 10, wherein the impeller comprises blades projecting from the exterior of the body for driving the primary flow. ### Claim 14 (depends on 10) The pump of claim 10, wherein the body comprises a plurality of magnetic poles proximate the bottom surface, the body being configured to be rotationally driven by and the axial position of the body being secured by an external rotating magnetic field.