Axial flow pump with multi-grooved rotor

• US 9,737,652 B2
• Filed: 05/10/2016
• Issued: 08/22/2017
• Est. Priority Date: 10/05/2005
• Status: Active Grant

• Current Assignee: Heartware,Inc. (Medtronic Plc), R & D Circuits Incorporated
• Original Assignee: Heartware,Inc. (Medtronic Plc)
• Inventors: LaRose, Jeffrey A., Shambaugh, Jr., Charles R., Trichi, Kartikeyan, Marquis, Richard A., White, Daniel G.
• Primary Examiner(s): DIETRICH, JOSEPH M
• Application Number:
  US15/151,058
• Publication Number:
  US 20160271308A1
• Time in Patent Office: 469 Days
• CPC Class Codes: A61M 60/148 in line with a blood vessel using resection or like techniques, e.g. permanent endovascular heart assist devices
• CPC Class Codes: A61M 60/196 replacing the entire heart, e.g. total artificial hearts [TAH]
• CPC Class Codes: A61M 60/237 the blood flow through the rotating member having mainly axial components, e.g. axial flow pumps
• CPC Class Codes: 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
• CPC Class Codes: A61M 60/422 the force acting on the blood contacting member being electromagnetic, e.g. using canned motor pumps
• CPC Class Codes: A61M 60/508 Electronic control means, e.g. for feedback regulation
• CPC Class Codes: A61M 60/806 Vanes or blades
• CPC Class Codes: A61M 60/81 Pump housings
• CPC Class Codes: A61M 60/82 Magnetic bearings
• CPC Class Codes: A61M 60/824 Hydrodynamic or fluid film bearings
• CPC Class Codes: F04D 29/0476 for axial pumps
• CPC Class Codes: F04D 3/02 of screw type

Abstract

An axial-flow blood pump includes a housing having an inlet and an outlet opposite therefrom. An impeller located within the housing is suspended during operation by magnetic forces between magnets or magnetized regions of the impeller and a motor stator surrounding the housing, and hydrodynamic thrust forces generated by a flow of blood between the housing and a plurality of hydrodynamic thrust bearing surfaces located on the impeller. A volute may be in fluid-tight connection with the outlet of the housing for receiving blood in the axial direction and directing blood in a direction normal to the axial direction. The volute has a flow-improving member extending axially from the volute and into the housing in a coaxial direction of the housing.

Claims

1. A blood pump, comprising:

a pump housing;

a rotor for pumping blood positioned in said housing, said rotor having an axis of rotation, a leading edge at a blood upstream end of said rotor and a trailing edge at a blood downstream end of said rotor, said rotor comprising peripheral land surfaces defined by one or more flow channels extending from said leading edge to said trailing edge, said channels being curved to drive blood in an axial direction as the rotor is rotated, a collective width of said flow channels in a circumferential direction of said rotor at each of some axial positions on a radial periphery of the rotor being substantially equal to or less than a collective total width of said peripheral land surfaces in the circumferential direction at said axial positions, said rotor further having one or more of a hydrodynamic bearing surface or a magnetic bearing to enable said rotor to rotate freely suspended within said housing a motor, said rotor including a plurality of magnetic poles; and

a stator including an electrically activated coil configured to magnetically interact with said magnetic poles to cause said rotor to rotate.

2. The blood pump of claim 1 in which the average depth of each flow channel is within the range of from about 1 mm to about 5 mm.

3. The blood pump of claim 2 in which said flow channels are substantially parallel.

4. The blood pump of claim 1 in which the depth of each flow channel is greater at said leading edge of said rotor than at said trailing edge.

5. The blood pump of claim 1 comprising a plurality of rotors within said housing axially aligned and spaced apart in the direction of blood flow within the housing.

6. The blood pump of claim 5 in which said rotors are ganged together of a common shaft to rotate together as one in the same direction.

7. The blood pump of claim 5 in which each rotor is suspended to rotate independently.

8. The blood pump of claim 5 in which each rotor rotates in a different rotational direction from at least one of an immediate upstream adjacent rotor and an immediate downstream adjacent rotor.

9. The blood pump of claim 5 in which each rotor rotates at a different rotational speed from the at least one of an immediate upstream adjacent rotor and an immediate downstream adjacent rotor.

10. The blood pump of claim 1, in which at least one said hydrodynamic bearing surface is positioned in one of said peripheral land surface areas and is configured to provide hydrodynamic control of a radial position of said rotor within said housing in a state of rotation of said rotor.

11. The blood pump of claim 1 in which said peripheral land surface areas of said rotor have substantially equal surface areas collectively defining a cylindrical periphery of the rotor, said cylindrical periphery being such that a gap exists between said cylindrical periphery of the rotor and an interior wall of said housing.

12. The blood pump of claim 11 in which each of said peripheral land surface areas comprises a first tapered hydrodynamic bearing surface extending in a substantially circumferential direction adjacent said blood upstream end of said rotor and a second tapered hydrodynamic bearing surface extending in a substantially circumferential direction adjacent said blood downstream end of said rotor, each of said first and second tapered hydrodynamic bearing surfaces having an entrance portion, said gap being larger at each of said entrance portions of said hydrodynamic bearing surfaces than at other portions of each of said tapered hydrodynamic bearing surfaces for hydrodynamic thrust control of a radial position of said rotor within said housing.

13. The axial flow blood pump of claim 11 in which said peripheral land surface areas comprise the hydrodynamic thrust bearing surfaces for hydrodynamic thrust control of a radial position of said rotor within said gap when said rotor is rotating.

14. The blood pump of claim 10 in which said at least one hydrodynamic bearing surface comprises shroud side walls extending substantially transverse to the rotation axis of the rotor.

15. The blood pump of claim 1 in which said housing comprises a first reduced interior diameter section adjacent one end of said rotor, each of said peripheral land surface areas comprising at least one said hydrodynamic bearing surface adjacent said first reduced interior diameter section for hydrodynamic thrust control of an axial position of said rotor within said housing.

16. The blood pump of claim 15 in which said housing comprises a second reduced interior diameter section at another end of said rotor opposite said one end, each of said peripheral land surface areas comprising a second hydrodynamic bearing surface adjacent said second reduced interior diameter section for hydrodynamic thrust control of the axial position of said rotor within said tubular housing.

17. The blood pump of claim 1 comprising said magnetic bearing, said bearing including a component exterior to said housing magnetically coupled to said rotor to thereby control an axial position of said rotor in said housing when said rotor is rotating.

18. A blood pump, comprising:

a pump housing;

a rotor for pumping blood positioned in said housing, said rotor having an axis of rotation, a leading edge at a blood upstream end of said rotor, and a trailing edge at a blood downstream end of said rotor, said rotor comprising a radially projection-free periphery defined by a plurality of peripheral land surfaces and one or more flow channels extending radially inwardly from said periphery separating said peripheral land surfaces, said one or more flow channels extending from said leading edge to said trailing edge, said channels being curved to drive blood in an axial direction as the rotor is rotated, said rotor further having one or more of a hydrodynamic bearing surface or a magnetic bearing to enable said rotor to rotate freely suspended within said housing, said rotor including a plurality of magnetic poles; and

a stator including an electrically activated coil configured to magnetically interact with said magnetic poles to cause said rotor to rotate.

19. The blood pump of claim 18 in which said housing comprises a first reduced interior diameter section adjacent one end of said rotor, each of said peripheral land surface areas comprising at least one said hydrodynamic bearing surface adjacent said first reduced interior diameter section for hydrodynamic thrust control of an axial position of said rotor within said housing.

20. The blood pump of claim 18, in which at least one said hydrodynamic bearing surface is positioned in one of said peripheral land surface areas and is configured to provide hydrodynamic control of a radial position of said rotor within said housing in a state of rotation of said rotor.

21. The blood pump of claim 18 in which said peripheral land surface areas of said rotor have substantially equal surface areas collectively defining said cylindrical periphery of the rotor, said cylindrical periphery being such that a gap exists between said cylindrical periphery of the rotor and an interior wall of said housing.

22. The blood pump of claim 21 in which each of said peripheral land surface areas comprises a first tapered hydrodynamic bearing surface extending in a substantially circumferential direction adjacent said blood upstream end of said rotor and a second tapered hydrodynamic bearing surface extending in a substantially circumferential direction adjacent said blood downstream end of said rotor, each of said first and second tapered hydrodynamic bearing surfaces having an entrance portion, said gap being larger at each of said entrance portions of said hydrodynamic bearing surfaces than at other portions of each of said tapered hydrodynamic bearing surfaces for hydrodynamic thrust control of a radial position of said rotor within said housing.