Abstract: An apparatus for use in an artificial heart assembly includes an internal coil adapted to be implanted beneath the skin of a subject and an external coil coupled to transmit electric power to the internal coil through the skin of the subject. The apparatus includes a DC-to-AC converter coupled to the external coil which selectively converts DC power from a DC power source into either a first frequency or a second frequency, the first frequency having a plurality of cycles each of a first duration and the second frequency having a plurality of cycles each of a second duration longer than the first duration. The DC-to-AC converter comprises four switching components each coupled in parallel with a respective one of four passive components and a drive circuit operatively coupled to the switching components.

Abstract: An artificial heart assembly is provided with a blood inlet conduit, a blood outlet conduit, a pump that pumps blood from the blood inlet conduit to the blood outlet conduit, and an internal electromagnetic coupler adapted to be implanted beneath the skin of a subject. A voltage regulator is operatively coupled to the internal electromagnetic coupler to generate an output voltage that is supplied to the pump. The voltage regulator causes the magnitude of the output voltage to be modulated in accordance with a transmit data signal. An external electromagnetic coupler is operatively coupled to generate an electric signal at least in part from the output voltage, and a decoding circuit is coupled to sense a parameter of the electric signal generated by the external electromagnetic coupler. The decoding circuit generates a receive data signal from the sensed electric signal, the receive data signal corresponding to the transmit data signal.

Abstract: A catheter having a first magnet is guided into a pocket of air entrapped in a pumping chamber for an artificial heart using a probe having a second magnet, a Hall-effect sensor an electronic circuit and an indicator disposed thereon. The Hall-effect sensor generates a voltage signal that is related to the distance between the catheter tip and the probe tip and that is measured by the electronic circuit and thereafter used to actuate the indicator. The indicator indicates when the probe is close enough to the catheter such that the catheter tip has been magnetically captured by the probe tip. Once magnetically captured, the probe tip, while remaining outside of the pumping chamber, is used to guide the catheter tip to an elevated portion of the pumping chamber wherein the pocket of entrapped air is located. A vacuum generating device attached to a distal end of the catheter tube is then used to withdraw the air from the pumping chamber.

Abstract: An artificial heart assembly, designed for implantation into a subject, which may be a total artificial heart or a ventricular assist device. The artificial heart assembly has a blood inlet conduit, a blood outlet conduit, a pumping mechanism for pumping blood from the blood inlet conduit to the blood outlet conduit, and a sensorless, DC brushless motor operatively connected to the pumping mechanism. The motor is reversibly driven in a first direction and a second direction, the motor changing between the first and second directions at a rate of at least 30 times per minute. The artificial heart assembly has means for periodically applying electrical signals to a plurality of the motor terminals while leaving at least one of the motor terminals unenergized, means for detecting a voltage at the unenergized motor terminal, and means for determining, based upon the voltage at the unenergized terminal, the angular position of the rotor with respect to the stator.