Blood pump actuator
First Claim
1. A blood pump for use with a ventricle which receives blood, comprising a direct drive actuator for positioning proximate said ventricle, a magnet positioned inside said actuator, a stationary coil means circumferentially surrounding said magnet and spaced therefrom sufficiently so that wear and contact are minimized, a piston means attached to said magnet for pumping said ventricle, a bearing for supporting said piston means, a housing for said actuator filled with hydraulic fluid for providing cooling for said actuator, said piston means having a generally cylindrical surface having two sets of opposed taper means, a first of said sets being separated from a second of said sets by a groove, and communication means for receiving hydraulic fluid in said groove, whereby contact between said piston means and said housing is substantially eliminated.
1 Assignment
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Accused Products
Abstract
An implantable blood pump actuator uses an efficient direct drive voice coil linear motor to power an hydraulic piston. The motor is immersed in oil and has but one moving part, a magnet which is attached to the piston. The piston is supported using a linear double acting hydrodynamic oil bearing that eliminates all wear and will potentially give an infinitely long life. There are no flexing leads, springs to break or parts to fatigue. A total artificial heart embodiment is very light, small, and as efficient as present prosthesis. The motor uses two commutated coils for high efficiency and has inherently low side forces due to the use of coils on both the inside and outside diameters of the magnet. The motor is cooled by forced convection of oil from the piston motion and by direct immersion of the coils in the oil. The highly effective cooling results in a smaller lighter weight motor.
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Citations
16 Claims
- 1. A blood pump for use with a ventricle which receives blood, comprising a direct drive actuator for positioning proximate said ventricle, a magnet positioned inside said actuator, a stationary coil means circumferentially surrounding said magnet and spaced therefrom sufficiently so that wear and contact are minimized, a piston means attached to said magnet for pumping said ventricle, a bearing for supporting said piston means, a housing for said actuator filled with hydraulic fluid for providing cooling for said actuator, said piston means having a generally cylindrical surface having two sets of opposed taper means, a first of said sets being separated from a second of said sets by a groove, and communication means for receiving hydraulic fluid in said groove, whereby contact between said piston means and said housing is substantially eliminated.
- 10. A blood pump for use with a ventricle which receives blood, comprising a direct drive actuator for positioning proximate said ventricle, a magnet positioned inside said actuator, a stationary coil means circumferentially surrounding said magnet and spaced therefrom sufficiently so that wear and contact are minimized, a piston means attached to said magnet for pumping said ventricle, a bearing for supporting said piston means, a housing for said actuator filled with hydraulic fluid for providing cooling for said actuator, said piston means having a generally cylindrical surface having two sets of raised steps, with lands on each side thereof, to function as a bearing.
- 13. A blood pump for use with a ventricle which receives blood, comprising a direct drive actuator for positioning proximate said ventricle, a magnet positioned inside said actuator, a stationary coil means circumferentially surrounding said magnet and spaced therefrom sufficiently so that wear and contact are minimized, a piston means attached to said magnet for pumping said ventricle, a bearing for supporting said piston means, a housing for said actuator filled with hydraulic fluid for providing cooling for said actuator, ventricle sacks for said ventricle, said fluid being displaced by said piston means to alternately compress and expand said sacks, respectively located on each side of said piston means, and valve means for said sacks for controlling inflow and outflow of unidirectionally pumped blood, wherein said piston means defines a hydrodynamic bearing surface and a clearance seal, causing said fluid to be displaced on each side of said piston means.
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16. A blood pump for pumping a ventricle which receives blood through an intake one-way valve and expels blood through an exhaust one-way valve, comprising:
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a piston for cyclically compressing said ventricle; a hydraulic bearing for supporting said piston for reciprocating movement; and a linear electric motor attached to said piston for cyclically driving said piston, said linear electric motor comprising; a radially magnetized ring axially attached to said piston; stationary inner and outer circumferentially wound coils coaxially surrounding said magnetized ring inside and outside so as to produce an axial force on said magnetized ring when electrically energized; a stationary stator providing a path for magnetic flux between a circumferential position radially outside of said magnetized ring and an axial position radially inside of said magnetized ring, said inner and outer coils being positioned between said stator and said magnetized ring; and a housing for said stator, magnetized ring and inner and outer coils, said housing being filled with hydraulic fluid for cooling and lubricating said linear motor.
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Specification