Multiple rotor, wide blade, axial flow pump

• US 20060245959A1
• Filed: 04/29/2005
• Published: 11/02/2006
• Est. Priority Date: 04/29/2005
• Status: Active Grant

• Current Assignee: Heartware,Inc. (Medtronic Plc)
• Original Assignee: Heartware,Inc. (Medtronic Plc)
• Inventors: LaRose, Jeffrey A., Shambaugh, Charles R. Jr.
• Granted Patent: US 7,972,122 B2
• Time in Patent Office: Days
• US Class Current: 417/423.500
• 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 60/178 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
• CPC Class Codes: A61M 60/196 replacing the entire heart, e.g. total artificial hearts [TAH]
• CPC Class Codes: A61M 60/232 Centrifugal pumps
• 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 60/804 Impellers
• CPC Class Codes: A61M 60/806 Vanes or blades
• CPC Class Codes: A61M 60/824 Hydrodynamic or fluid film bearings
• CPC Class Codes: A61M 60/825 Contact bearings, e.g. ball-and-cup or pivot bearings
• CPC Class Codes: F04D 13/0633 Details of the bearings
• CPC Class Codes: F04D 13/064 Details of the magnetic circuit
• CPC Class Codes: F04D 13/0646 the hollow pump or motor shaft being the conduit for the working fluid
• CPC Class Codes: F04D 29/181 Axial flow rotors F04D29/185 take precedence
• CPC Class Codes: F04D 29/669 especially adapted for liquid pumps F04D29/18 takes precedence
• CPC Class Codes: F04D 3/02 of screw type

Abstract

A blood pump comprises a pump housing; a plurality of rotors positioned in said housing, each rotor comprising an impeller having a hydrodynamic surface for pumping blood; and a motor including a plurality of magnetic poles carried by each impeller, having motor stators, each including electrically conductive coils located adjacent to or within the housing. At least one of the rotors is adopted to rotate clockwise, and at least one of rotors is adopted to rotate counterclockwise. By this means, stator or stationary blades between the rotors may not be needed.

Claims

1. A blood pump, comprising:

a pump housing;

a plurality of rotors positioned in said housing, each rotor comprising an impeller having a hydrodynamic surface for pumping blood;

a motor including a plurality of magnetic poles carried by each impeller, and motor stators, each including electrically conductive coils, located adjacent to or within said housing;

at least one of said rotors being adapted to rotate clockwise and at least one of said rotors being adapted to rotate counterclockwise.

2. The blood pump of claim 1 in which said rotors are spaced from each other.

3. The blood pump of claim 2 in which said rotors are free of stationary blades positioned between them.

4. The blood pump of claim 1 in which said rotors are free to rotate at different rates from each other.

5. The blood pump of claim 1 in which more than two rotors are present, adjacent rotors rotating in opposite directions from each other.

6. The blood pump of claim 1 in which two rotors are present.

7. The blood pump of claim 1 in which said rotors are spaced from each other and are free of stationary blades positioned between them, said rotors being free to rotate at different rates from each other.

8. The blood pump of claim 7 in which more than two rotors are present, adjacent rotors rotating in opposite directions from each other.

9. The blood pump of claim 8 in which said rotors each comprise radially outwardly extending, blade-like projections that define generally longitudinally extending spaces between said projections, said projections being shaped to form curves in said spaces of a shape tending to drive blood in said spaces in an axial direction when rotated, said spaces collectively having a total width along most of their lengths, at the radial periphery of the rotor, that is substantially equal to or less than the collective total width of said projections along most of their lengths at said radial periphery.

10. The blood pump of claim 1 in which said rotors each comprise radially outwardly extending, blade-like projections that define generally longitudinally extending spaces between said projections, said projections being shaped to form curves in said spaces of a shape tending to drive blood in said spaces in an axial direction when rotated, said spaces collectively having a total width along most of their lengths, at the radial periphery of the rotor, that is substantially equal to or less than the collective total width of said projections along most of their lengths at said radial periphery.

11. The blood pump of claim 10 in which at least one magnetic bearing system is also provided to help to position said rotors.

12. The blood pump of claim 11 in which said at least one magnetic bearing system comprises permanent magnets mounted in said blade-like projections, said motor being of the radial flux gap design, whereby axial, magnetic forces hold the rotor in position.

13. The blood pump of claim 1 in which the motor comprises at least one separate, hermetically sealed unit that slides over said pump housing into position and is secured thereto, said pump housing being tubular.

14. The blood pump of claim 13 in which said housing is cylindrical.

15. The blood pump of claim 1 in which said plurality of rotors positioned in said housing are positioned in series flow, for increased pumping pressure capacity.