Sealless rotary blood pump with passive magnetic radial bearings and blood immersed axial bearings
First Claim
1. A sealless blood pump, comprising:
- a. a pump housing, having an elongated inlet tube on one end and an impeller casing on the other end, said casing including a discharge tube;
b. a rotor mounted for rotation within said housing, said rotor having an elongated shaft portion and an impeller attached to said shaft portion, said impeller being located within said impeller casing;
c. radial magnetic bearings carried by said shaft potion, and radial magnetic bearings carried by said housing for maintaining said shaft portion of said rotor coaxially within said inlet tube of said housing, a primary flow channel for blood being provided by an annular volume between said shaft and said radial magnetic bearings carried by said housing;
d. a thrust bearing for restraining said rotor from translating past a predetermined position along its axis;
e. a motor rotor carried by said impeller; and
f. a motor stator within said housing adjacent said impeller, for producing an electromagnetic field.
4 Assignments
0 Petitions
Accused Products
Abstract
An implantable rotary blood pump without a shaft seal. The pump includes a rotary element, having a pump impeller on one end. The impeller is specially designed with large, thick blades and tall, narrow blood channels, to minimize hemolysis. The rotary element and the impeller are maintained in radial alignment by respective, passive magnetic bearings. Axial restraint of the rotary element is provided by blood immersed thrust bearings, spaced a slight distance from either end of the rotor. Drive for the rotary element is provided by a structurally integrated, brushless electric motor. A plurality of permanent magnets is arranged in circular fashion within the impeller, constituting a rotor for the motor. The motor'"'"'s stator includes circular windings of conductive wire, located within the pump housing and concentric with the rotor. With the stator energized, electromagnetic forces between the stator and the motor rotor cause the rotary element and the impeller to rotate. During operation, the rotary element shuttles back and forth along its axis between the thrust surfaces in response to heart pulsations. This bi-stable operation of the pump, allows fresh blood to flush through the thrust bearings in continuous fashion, minimizing the likelihood of thrombosis developing from operation of the pumps.
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Citations
44 Claims
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1. A sealless blood pump, comprising:
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a. a pump housing, having an elongated inlet tube on one end and an impeller casing on the other end, said casing including a discharge tube; b. a rotor mounted for rotation within said housing, said rotor having an elongated shaft portion and an impeller attached to said shaft portion, said impeller being located within said impeller casing; c. radial magnetic bearings carried by said shaft potion, and radial magnetic bearings carried by said housing for maintaining said shaft portion of said rotor coaxially within said inlet tube of said housing, a primary flow channel for blood being provided by an annular volume between said shaft and said radial magnetic bearings carried by said housing; d. a thrust bearing for restraining said rotor from translating past a predetermined position along its axis; e. a motor rotor carried by said impeller; and f. a motor stator within said housing adjacent said impeller, for producing an electromagnetic field. - View Dependent Claims (2, 4, 5, 6, 7)
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3. A sealless blood pump comprising:
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a pump housing, having an elongated inlet tube on one end and an impeller casing on the other end, said casing including a discharge tube; a rotor mounted for rotation within said housing, said rotor having an elongated shaft portion and including an impeller attached to said shaft portion, said impeller being located within said impeller casing; radial magnetic bearings for maintaining said shaft portion of said rotor coaxially within said inlet tube of said housing, a blood flow path being provided by an annular volume between said shaft and said housing; a thrust bearing for restraining said rotor from translating past a predetermined position along its axis; a motor rotor on a surface of said impeller; and a motor stator within said housing adjacent said surface of said impeller, for producing an electromagnetic field; said thrust bearing restraining said rotor within two predetermined axial positions, between which said rotor may shuttle in response to a varying blood pressure across said inlet tube and said outlet tube.
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8. A sealless blood pump, comprising:
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a. a pump rotor, said rotor having an elongated shaft with an upstream end and a downstream end, said rotor further including an impeller attached to said downstream end of said shaft; b. a pump housing, said housing having an elongated inlet tube on one end, said shaft being enclosed by and concentric with said tube, said housing further including a casing on the other end surrounding said impeller, said casing having an outlet tube; c. radial magnetic bearings carried by said shaft portion and radial magnetic bearings carried by said housing for coaxially maintaining said shaft within said tubular inlet of said housing for rotation about a longitudinal axis, said radial magnetic bearings carried by said shaft and said radial magnetic bearings carried by said housing providing between them an annular volume defining a primary flow channel for blood; d. a first thrust bearing within said casing, said impeller having a bearing surface in contact with said first thrust bearing; e. a permanent magnet motor rotor carried by said impeller; f. an electromagnetic motor stator within said housing adjacent said impeller; g. a power supply having an electrical output in connection with said motor stator. - View Dependent Claims (9, 10, 11, 12, 14, 15, 16)
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13. A sealless blood pump, comprising:
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a pump rotor, said rotor having an elongated shaft with an upstream end and a downstream end, said rotor further including an impeller attached to said downstream end of said shaft; a pump housing, said housing having an elongated inlet tube on one end, said shaft being enclosed by and concentric with said tube, said housing further including a casing on the other end surrounding said impeller, said casing having an outer tube; radial magnetic bearings for coaxially maintaining said shaft within said tubular inlet of said housing for rotation about a longitudinal axis, an annular volume between said shaft and said housing defining a blood flow path; a first thrust bearing within said casing, said impeller having a bearing surface in contact with said first thrust bearing; a permanent magnet motor rotor on a surface of said impeller; an electromagnetic motor stator within said housing adjacent said surface of said impeller; a power supply having an electrical output in connection with said motor stator; further including a second thrust bearing within said inlet tube, said shaft having a bearing surface at said upstream end in contact with said second thrust bearing; said first and second thrust bearings being spaced apart a distance slightly greater than the length of said rotor, wherein blood pressures between said inlet tube and said outlet tube vary to shuttle said rotor between said first and second thrust bearings.
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17. A centrifugaI blood pump having a rotor, an inlet tube and an impeller casing, said inlet tube including a bearing supporting the rotor for rotation about a longitudinal axis, comprising:
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a. said rotor being rotatable within the inlet tube, said rotor having an upstream end and a downstream end; b. a disc-shaped impeller having a central, upper face portion attached to said downstream end of said rotor and located within the casing, said impeller having a plurality of blade sectors, each of said sectors being separated from an adjacent sector by a channel extending continuously from said upper face portion to a lower face portion, each of said channels beginning with a leading edge, adjacent said shaft and ending with a trailing edge at an outer periphery of said impeller, said channel serving as a continuous fluid path through the impeller from said upper face portion to said lower face portion and functioning to increase the effective working area of the impeller; and c. a blood flow path on the outside of said rotor for bringing the blood to said upper face portion for passage through said channels. - View Dependent Claims (18, 19, 20)
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21. A sealless blood pump, comprising:
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a pump housing, having an inlet tube on one end and an impeller casing on the other end, said casing including an outlet; a rotor mounted for rotation within said housing, said rotor having an elongated shaft portion and including an impeller attached to said shaft portion, said impeller being located within said impeller casing; radial magnetic bearings carried by said shaft portion, and radial magnetic bearings carried by said housing for maintaining said shaft portion of said rotor within said inlet tube of said housing, a primary flow channel for blood being provided by an annular volume between said shaft and said radial magnetic bearings carried by said housing; and thrust bearings for restraining said rotor from translating past a predetermined position along its axis, said thrust bearings restraining said rotor within two predetermined axial positions, between which said rotor may shuttle in response to a varying blood pressure across said inlet tube and said outlet.
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22. A sealless blood pump, comprising:
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a pump housing, having an inlet tube on one end and an impeller casing on the other end, said casing including an outlet; a rotor mounted for rotation within said housing, said rotor having an elongated shaft portion and an impeller attached to said shaft portion, said impeller being located within said impeller casing; radial magnetic bearings for maintaining said shaft portion of said rotor within said inlet tube of said housing, a blood flow path being provided by an annular volume between said shaft and said housing; thrust bearings for restraining said rotor from translating past a predetermined position along its axis, said thrust bearings restraining said rotor within two predetermined axial positions, between which said rotor may shuttle in response to a varying blood pressure across said inlet tube and said outlet; said thrust bearings being located at opposed ends of said rotor with the distance between said thrust bearings being greater than the overall length of said rotor. - View Dependent Claims (23)
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24. A sealless centrifugal blood pump having an inlet tube and an impeller casing, said inlet tube including a bearing for supporting a rotor for rotation about a longitudinal axis, comprising:
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a rotor, said rotor comprising a rotatable, elongated support shaft within the inlet tube, said shaft having an upstream end and a downstream end; a disc-shaped impeller having a central, upper face portion attached to said downstream end of said shaft and located within the casing, said impeller having a plurality of blade sectors, each of said sectors being separated from an adjacent sector by a channel extending from said upper face portion to a lower face portion; said channels serving as a fluid path through the impeller and functioning to increase the effective working area of the impeller; and a plurality of permanent magnets unitary with and located within said blade sectors. - View Dependent Claims (25)
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26. A sealless centrifugal blood pap having an inlet tube and an impeller casing, said inlet tube including a bearing for supporting a rotor for rotation about a longitudinal axis, comprising:
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a rotor, said rotor comprising a rotatable, elongated support shaft within the inlet tube, said shaft having an upstream end and a downstream end; a disc-shaped impeller having a central, upper face portion attached to said downstream end of said shaft and located within the casing, said impeller being thick in the axial direction and having a plurality of blade sectors, each of said sectors being separated from an adjacent sector by a channel extending from said upper face portion to a lower face portion; said channels serving as a fluid path through the impeller and functioning to increase the effective working area of the impeller; and said impeller blade sectors defining sealed, individual hollow chambers to reduce the density of the impeller. - View Dependent Claims (27)
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28. A sealless blood pump, comprising:
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a pump housing, having an inlet tube on one end and an impeller casing on the other end, said casing including an outlet; a rotor mounted for rotation within said housing, said rotor having an elongated shaft portion and an impeller attached to said shaft portion, said impeller being located within said impeller casing; radial magnetic bearings carried by said shaft portion, and radial magnetic bearings carried by said housing for maintaining said shaft portion of said rotor within said inlet tube of said housing, a primary flow channel for blood being provided by an annular volume between said shaft and said radial magnetic bearings carried by said housing; and a rotor motor, said motor including a plurality of permanent magnets carried by said impeller, a motor stator including an electrically conductive coil, said motor stator having a ring-shaped configuration and surrounding said rotor. - View Dependent Claims (29, 30, 31)
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32. A sealless blood pump, comprising:
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a pump housing, having an inlet tube on one end and an impeller casing on the other end, said casing including an outlet; a rotor mounted for rotation within said housing, said rotor having an elongated shaft portion with a transverse dimension smaller than an inner dimension of said inlet tube, said rotor further including an impeller attached to said shaft portion, said impeller being located within said impeller casing; radial magnetic bearings for maintaining said shaft portion of said rotor within said inlet tube of said housing, a blood flow path being provided by an annular volume between said shaft and said inner diameter; and a thrust bearing for restraining said rotor from translating past a predetermined position along its axis, said thrust bearing being located outside of the axis of rotation of said rotor. - View Dependent Claims (33, 34, 35, 36, 38)
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37. A sealless blood pump, comprising:
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a pump housing; a rotor mounted for rotation within said housing; radial magnetic bearings for maintaining said rotor within said housing; and thrust bearings for restraining said rotor from translating past a predetermined position along its axis, said thrust bearings restraining said rotor within two axial positions between which said rotor may shuttle in response to a varying blood pressure.
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39. A sealless blood pump, comprising:
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a pump housing, having an inlet tube on one end and an impeller casing on the other end, said casing including an outlet; a rotor mounted for rotation within said housing, said rotor having an elongated shaft portion and including an impeller attached to said shaft portion, said impeller being located within said impeller casing; radial magnetic bearings carried by said shaft portion, and radial magnetic bearings carried by said housing for maintaining said shaft portion of said rotor within said inlet tube of said housing, a primary flow channel for blood being provided by an annular volume between said shaft and said radial magnetic bearings carried by said housing; and a thrust bearing for restraining said rotor from translating past a predetermined position along its axis, said thrust bearing being located outside of the axis of rotation of said rotor. - View Dependent Claims (40, 41, 42, 43)
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44. A sealless blood pump, comprising:
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a pump housing, having an inlet tube on one end and an impeller casing on the other end, said casing including an outlet; a rotor mounted for rotation within said housing, said rotor having an elongated shaft portion and an impeller attached to said shaft portion, said impeller being located within said impeller casing; radial magnetic bearings carried by said shaft portion, and radial magnetic bearings carried by said housing for maintaining said shaft portion of said rotor within said inlet tube of said housing, a primary flow channel for blood being provided by an annular volume between said shaft and said radial magnetic bearings carried by said housing; and a rotor motor, said motor including a plurality of permanent magnets located within said impeller and extending axially;
a motor stator including an electrically conductive coil, said motor stator having a ring-shaped configuration and located within said housing.
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Specification