Blood pump having a magnetically suspended rotor
First Claim
1. A pump for pumping blood, comprising:
- a housing;
a stator disposed within the housing and coupled to the housing;
a rotor disposed within the housing and suspended around the stator;
the rotor and stator defining a primary blood flow path between the rotor and the housing and a secondary blood flow path between the rotor and the stator;
at least two radial magnetic bearings for suspending the rotor between the stator and the housing, said radial magnetic bearings each comprising at least one stator suspension magnet disposed within the stator and at least one rotor suspension magnet disposed within the rotor, the stator and rotor suspension magnets communicating across the secondary flow path; and
a motor for rotating the rotor with respect to the stator, said motor comprising at least one electromagnetic coil within the housing, said electromagnetic coil communicating with at least one rotor motor magnet in the rotor, said communication being across the primary flow path to rotate the rotor with respect to the stator and thereby pump blood through the pump.
5 Assignments
0 Petitions
Accused Products
Abstract
A blood pump preferably has a magnetically suspended rotor that rotates within a housing. The rotor may rotate about a stator disposed within the housing. Radial magnetic bearings may be defined within the stator and the rotor in order to suspend the rotor. The radial magnetic bearings may be passive magnetic bearings that include permanent magnets disposed within the stator and the rotor or active magnetic bearings. The pump may further include an axial magnetic bearing that may be either a passive or an active magnetic bearing. A motor that drives the rotor may be disposed within the housing in order to more easily dissipate heat generated by the motor. A primary flow path is defined between the rotor and the stator, and a secondary flow path is defined between the stator and the rotor. Preferably, a substantial majority of blood passes through the primary flow path. The secondary flow path is large enough so that it provides adequate flushing of the secondary flow path while being small enough to permit efficient operation of the radial magnet bearings across the secondary flow path.
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Citations
25 Claims
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1. A pump for pumping blood, comprising:
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a housing;
a stator disposed within the housing and coupled to the housing;
a rotor disposed within the housing and suspended around the stator;
the rotor and stator defining a primary blood flow path between the rotor and the housing and a secondary blood flow path between the rotor and the stator;
at least two radial magnetic bearings for suspending the rotor between the stator and the housing, said radial magnetic bearings each comprising at least one stator suspension magnet disposed within the stator and at least one rotor suspension magnet disposed within the rotor, the stator and rotor suspension magnets communicating across the secondary flow path; and
a motor for rotating the rotor with respect to the stator, said motor comprising at least one electromagnetic coil within the housing, said electromagnetic coil communicating with at least one rotor motor magnet in the rotor, said communication being across the primary flow path to rotate the rotor with respect to the stator and thereby pump blood through the pump. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A system for pumping blood, comprising:
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(i) a pump, comprising;
a housing that has an inlet and an outlet;
a stator disposed within the housing and having a first end, disposed at the inlet, about which a plurality of stator blades are disposed, a second end, disposed at the outlet, about which a plurality of stator blades are disposed and a stationary hub that connects the first end to the second end;
a rotor, suspended between the stationary hub and the housing;
a first radial magnet bearing defined by a first set of magnets of alternating polarity, disposed within the rotor, that define an outer race and a second set of magnets of alternating polarity, disposed within the stator stationary hub, that define an inner race, the inner race and the outer race communicating across a gap between the stationary hub and the rotor to suspend the rotor about the stationary hub;
a thrust bearing defined by a pair of thrust coils, disposed within the housing, and a pair of magnetic poles, disposed within the rotor, each of the thrust coils interacting with one of the magnetic poles to produce an axial force on the rotor to position the rotor axially within the housing;
a sensing coil, disposed within the stator, that senses the axial position of the rotor; and
(ii) a controller, coupled to the sensing coil of the pump that controls an electrical current flowing through the thrust coils to produce a correcting force that positions the rotor axially in response to the position sensed by the sensing coil. - View Dependent Claims (15, 16, 17, 18)
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19. A pump for pumping blood, comprising:
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a housing that has an inlet and an outlet;
a stator, disposed within the housing, and having a first end, that is coupled to the housing proximate to the inlet and a second end, that is coupled to the housing proximate to the outlet;
a rotor, magnetically suspended between the stator and the housing;
a radial magnetic bearing that includes a rotor magnet, disposed within the rotor, and a stator magnet, disposed within the stator and aligned with the rotor magnet, the interaction of the rotor magnet and the stator magnet suspending the rotor radially between the housing and the stator;
a primary flow path defined between the rotor and the housing;
a secondary flow path defined between the rotor and the stator, the secondary flow path being large enough to provide adequate flushing of the secondary flow path and small enough so that the rotor magnet and the stator magnet can interface to suspend the rotor radially. - View Dependent Claims (20, 21, 22, 23, 24, 25)
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Specification