Patents by Inventor John C. Moise

John C. Moise has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4908012
    Abstract: An implantable ventricular assist system uses a small high-speed axial flow blood pump which may be grafted into the patient's circulatory system. The pump includes a blood tube in which the pump rotor and stator are coaxially contained, and a motor stator surrounding the blood duct. A permanent magnet motor rotor is integral with the pump rotor. Purge fluid for the hydrodynamic bearings of the device and power for the motor are preferably percutaneously introduced from extracorporeal sources worn by the patient. The purge fluid is introduced into the pump stator blades. This construction avoids the creation of discontinuities in the blood path wall due to the routing of drive power and/or fluid supply elements through the blood path wall. The described construction greatly reduces the size of the implant needed for a given blood flow rate and enhances its physiological compatibility with the body.
    Type: Grant
    Filed: August 8, 1988
    Date of Patent: March 13, 1990
    Assignee: Nimbus Medical, Inc.
    Inventors: John C. Moise, Richard K. Wampler, Kenneth C. Butler
  • Patent number: 4895557
    Abstract: A disposable, sterilizable cable drive unit for an intravascular blood pump includes a rotor enclosed in a fluid-tight enclosure which can be slipped into the stator of a drive motor. The unit is connectable to a constant-rate purge fluid supply and to a dual-lumen cable sheath. One lumen provides a sterile purge fluid path; the other carries the drive cable to the blood pump and provides a return path for a flushing fluid in which the cable is immersed. The flushing unit is derived from the purge fluid supply at a constant rate, and the rotor may also be immersed in it if desired. The unit is held in the drive motor by a manually operated detent, and the self-centering action of the rotor aligns it with the stator when the motor is energized. The motor is mounted on a gimbal so as to be alignable with the cable sheath at its point of insertion into the patient's vascular system, in order to prevent stresses on the patient and kinks in the cable sheath.
    Type: Grant
    Filed: December 7, 1987
    Date of Patent: January 23, 1990
    Assignee: Nimbus Medical, Inc.
    Inventors: John C. Moise, John W. Carriker, Reginald R. Baxter
  • Patent number: 4846152
    Abstract: A miniature high-speed intravascular blood pump is formed as a single stage with two rows of rotor blades and a single row of stator blades within a tubular housing. The rotor's first row produces a mixed centrifugal and axial flow, while the rotor's second row produces a purely axial flow. The blades of the second row are shaped so as to produce a uniform blood flow along the trailing edges of the blades. For this purpose, the bases of the outer trailing edges of the second row blades have a negative propulsion angle. The pump has a purge-sealed hydrostatic bearing which is spring-loaded for minimum gap. The pump is driven by a cable encased in a dual-lumen, fluid-filled cable sheath formed of a coextrusion of a soft, blood-compatible outer layer and a stiff, abrasion-resistant inner layer. The cable sheath serves both as a purge fluid supply for the bearing, and as a means for flushing abraded debris away from the pump.
    Type: Grant
    Filed: November 24, 1987
    Date of Patent: July 11, 1989
    Assignee: Nimbus Medical, Inc.
    Inventors: Richard K. Wampler, John W. Carriker, Kenneth C. Butler, John C. Moise
  • Patent number: 4779614
    Abstract: An implantable axial flow blood pump maximizes the blood flow while minimizing the dimensions of the pump. By magnetically suspending a rotor of relatively small diameter coaxially in a cylindrical blood conduit of substantially larger inner diameter, an adequate flow area through the pump is provided, and the need for bearings, lubrication and seal purging fluid is eliminated. This is made possible by the use of neodymium-boron-iron rotor magnets which allow a substantial gap between the static motor armature and the rotor. The rotor is simultaneously torqued and maintained in a position coaxial with the blood conduit by individually varying the current in the armature windings while they are being commutated. The position of the rotor axis is accurately sensed by placing magnetically permeable strips into opposite ends of the pump stator blades in such a manner that they transmit to Hall sensors variations in an annular magnetic field surrounding the rotor adjacent the ends of the pump stator blades.
    Type: Grant
    Filed: April 9, 1987
    Date of Patent: October 25, 1988
    Assignee: Nimbus Medical, Inc.
    Inventor: John C. Moise
  • Patent number: 4704121
    Abstract: Thrombus formation in an implantable blood pump is prevented by using a close-tolerance purge seal for the impeller shaft or rotor. A blood-compatible fluid is used for the purge fluid (which is preferably also the bearing fluid), and the purge flow into the blood stream presents to the blood stream a benign interface between the rotating and stationary parts of the pump. The rotating and stationary surfaces adjacent the interface are so configured as to present an essentially continuous smooth surface across the interface which can be swept by the blood stream and presents no cavities in which the blood can stagnate. The close clearances of the purge seal allow a sufficient purge flow rate to be maintained with only a minute amount of purge fluid; and in accordance with one aspect of the invention, the purge fluid can be derived from the blood stream by a protein-filtering membrane system so that no external replenishment of the purge fluid supply is necessary.
    Type: Grant
    Filed: September 28, 1983
    Date of Patent: November 3, 1987
    Assignee: Nimbus, Inc.
    Inventor: John C. Moise