Abstract: A heart-assist system and a method for operating same are described in which a pump is connected to a ventricle to receive output therefrom. An actuator operates to cause the pump to conduct a fill cycle in which it receives output from the ventricle to which it is connected, and to conduct an eject cycle in which the contents of the pump are expelled. The time of initiation of at least one of the fill cycle and the eject cycle is varied in relation to systole of the ventricle to which the pump is connected to thereby vary the loading of the ventricle. Several techniques for detecting termination of systole are described including a compliant stop on the pump.

Abstract: A biventricular circulatory support system for a human patient is described. A mechanical first pump for assuming at least a part of the pumping load of the patient's left ventricle is implanted in the patient. A second pump for assuming at least a part of the pumping load of the patient's right ventricle is also implanted. The second pump includes a surgically prepared skeletal muscle pedicle with nerves and blood supply substantially intact. The muscle pedicle is applied directly to the right ventrical or is applied to an artificial pump sac. Electrical signals are applied to the first and second pumps as appropriate to cause pumping action in a predetermined relationship.

Abstract: A solenoid closure servo control eliminates impact of the solenoid poles against each other upon closure of the device. A model of the device closure is obtained from a parameter of initial gap. During closure of the device, the rate of closure of the gap of the solenoid and the force in balance between the spring and magnetic force is calculated and compared to the model. Imbalances are corrected by applying a corrective voltage to the solenoid coils.

Abstract: Real time servo control in a nonlinear, cyclical dynamic system adjusts the energy applied to a prime mover from a source of the energy as a linear function of an error between the measured load characteristics and modeled load characteristics. The modeled load characteristics are linearized as a function of the initial conditions of the load at the beginning of each cycle.

Abstract: An infusion system is disclosed for delivering precisely regulated and variable dosages of drugs. The device includes a reservoir for containing the drug, a catheter for delivering drug to the body, and actuating means responsive to a signal applied externally of the body for initiating delivery of a precisely regulated dosage. The actuating means include; a solenoid driven miniature pump which is controlled by an implanted controller and driven by an implanted power source. The implanted controller provides a basal dosage rate which itself may be variable or constant and which may be altered by telemetry signals delivered from outside the body. In addition, the internal device is operable by an external unit which may be set at a different rate from that which the internal or implanted controller is set and which, in addition, provides power for operating the implanted device.

Abstract: Multiple embodiments of an implantable infusion device for delivering precisely regulated dosages of drugs are disclosed, each device including reservoir means for containing the drug, catheter means for delivering the drug to the body and an actuating means which is responsive to a signal applied externally of the body for initiating delivery of a precisely regulated dosage. In one embodiment, the device is implanted subcutaneously to permit actuation by a solenoid driven element responsive to coded telemetry signal applied through the skin. In additional embodiments, the reservoir is pressurized for example, by means of vapor pressure or a mechanical spring, the drug under pressure in the reservoir being released in response to an externally applied signal.

Abstract: A blood pumping device is described for internal use in humans or animals and which is particularly suitable for use as a left ventricular assist device. The device is comprised of a unitary pancake-shaped deformable sac of flexible resilient, blood compatible material. A pair of oppositely acting plates on each side of the pancake-shaped sac are moved toward and away from each other by the action of driving means to deform the sac and provide the pumping action. Inlets and outlets are arranged in the annular side wall of the sac.

Abstract: A compensator designed to be implanted within a living body and connected to an implanted reciprocating blood pump. A housing defines a gas-tight chamber which is separated into front and rear portions by a flexible membrane. A piston attached to the membrane guides the movement of the membrane, and a spring mechanism which links the piston and the housing is designed to maintain substantially constant pressure in the front chamber throughout the discharge and fill strokes of the reciprocating blood pump. Two pivoted, diametrically opposed, compression springs are compressed at rest at the end of the fill stroke and exert a force on the membrane which overcomes the differential pressure acting in the opposite direction when the membrane moves so as to expand the rear chamber volume.

Abstract: A power supply system to operate an implanted electric-powered device such as a blood pump. A secondary coil having a biocompatible covering is implanted to subcutaneously encircle either the abdomen or the thigh at a location close to the exterior skin. The secondary coil is electrically interconnected with an implanted storage battery and the blood pump. A primary coil of overlapping width is worn by the patient at a location radially outward of the secondary coil. An external battery plus an inverter circuit in a pack is attached to a belt having a detachable buckle connector which is conventionally worn about the waist. Efficient magnetic coupling is achieved through the use of two air-core windings of relatively large diameter.

Abstract: An intravenous and intra arterial delivery system is described having a disposable cassette actuated by a pump and control electronics for providing positive but variable delivery rates. The cassette is self-priming and provides protection against the delivery of air by being unable to impel air, and means provide an indication of excessive air in the cassette. The electronics has low power consumption so as to be suitable for battery operation, such as by way of rechargeable batteries. A pressure sensor in the delivery line may be used to sense infiltration. The system further features a provision for predetermining the amount of fluid to be delivered, and a detection system for detecting an empty supply bottle.

Abstract: A method and apparatus for analyzing pulmonary function including diffusing capacity and cardiac output or local pulmonary blood flow while necessarily determining alveolar volume in order to complete the above-noted analysis. In order to provide a rapid response in each of the abovenoted analyses or determinations, appropriate gases are caused to be inhaled and exhaled through a sample cell wherein a percentage of each gas may be constantly monitored during inhalation and exhalation by means of non-dispersive infrared absorption techniques, the sample cell and associated components of the pulmonary function analyzing device including additional features to facilitate the abovenoted analyses and determinations, the combination of gases employed for monitoring the pulmonary functions being selected to permit accurate detection by infrared absorption techniques.