Abstract: A gas transfer apparatus readily adapted for oxygenating blood includes a housing with a hollow internal chamber having a fiber mat consisting of two sets of intermingled hollow fibers with one set of fibers having micropores formed in the walls thereof and the other set having solid liquid impermeable walls. The housing for the apparatus is designed such that the blood being processed passes substantially uniformly across the entire cross section of the fiber mat whereby a treating gas such as oxygen being directed through the microporous fibers can be diffused into the oxygen deficient blood while excess CO.sub.2 in the blood can cross diffuse into the interior of the fiber and be removed from the apparatus. Simultaneously with the cross diffusion of gas between the microporous fibers and the blood, a thermal conducting fluid such as water is passed through the solid walled fibers to maintain or regulate the temperature of the blood in the apparatus.

Abstract: Blood is pumped by a pump, preferably a bi-concave diaphragm pump. When the blood pump is full of blood, this full condition is detected and a batch of blood is emptied completely from the pump for delivery to the patient. A second pump, also preferably a bi-concave diaphragm pump, pumps anti-coagulant into the blood as it is recovered. This second pump ejects its contents every time the blood pump ejects its contents. Particulates in the blood are removed by a filter and air is removed by a defoamer. Fluid and very small matter in the blood may be removed in a tangential flow separator. Blood flows through a narrow passage along one or more membranes, with fluid and small matter passing through the membrane(s). A washing fluid may be added to blood within this separator. A third pump, again preferably a bi-concave diaphragm pump, is used to add this washing fluid. The third pump is emptied whenever the blood pump empties, and thereafter refills with washing fluid.

Abstract: An arterial graft prosthesis comprises a first interior zone of a solid, segmented polyether-polyurethane material surrounded by a second zone of a porous, segmented polyether-polyurethane and a third zone immediately surrounding said second zone and of a solid, segmented polyether-polyurethane. The interior zone may have a lining or blood interface of a microporous zone of segmented polyether-polyurethane, and the exterior, third zone may be surrounded by a tissue interface of a microporous zone of segmented polyether-polyurethane. In some instances the exterior may be confined by a tube of substantially non-stretchable netting fastened in place at chosen, spaced intervals or other forms of reinforcement may be employed. Other materials can be used.

Abstract: An electronic control system for controlling the operation of a cardiac prosthesis is disclosed. The cardiac prosthesis includes dominant and subordinate ventricles which receive blood in response to body requirements and an actuation device coupled to the ventricles for ejecting blood from the ventricles. The electronic control system includes sensing devices to determine the volume of blood in the ventricles as a function of time. A control device, which in the preferred embodiment is a programmed microcomputer, includes a clock controller which first determines the filling flow rates of the ventricles from the volume information from the sensing devices. The ventricle with the greatest filling flow rate is selected as the dominant ventricle. The clock controller then adjusts the heart rate of the cardiac prosthesis as a function of the filling flow rate of the dominant ventricle to allow just enough time for the dominant ventricle to fill completely.

Abstract: An arterial graft prosthesis comprises a first interior zone of a solid, segmented polyether-polyurethane material surrounded by a second zone of a porous, segmented, polyether-polyurethane and a third zone immediately surrounding said second zone and of a solid, segmented polyether-polyurethane. The interior zone may have a lining or blood interface of a microporous zone of segmented polyether-polyurethane, and the exterior, third zone may be surrounded by a tissue interface of a microporous zone of segmented polyether-polyurethane. In some instances the exterior may be confined by a tube of substantially non-stretchable netting fastened in place at chosen, spaced intervals or other forms of reinforcement may be employed. Other materials can be used.

Abstract: An engine has preferably coupled together a reciprocating air compressor discharging through a heat exchanger into a reciprocating cylinder piston combination, the flow into the piston cylinder combination being controlled by a cam-actuated inlet valve which is maintained open for a substantial fraction of the out-stroke of the combustion piston. There is also an exhaust valve from the combustion chamber which releases exhaust gas to the heat exchanger for transfer of thermal energy to the incoming compressed air. A fuel injector supplies fuel to the compressed air entering through the inlet valve into the combustion chamber over a large part of the out-stroke of the power piston.

Abstract: A cardiac prosthesis having an hydraulically actuated compressible blood pump. An actuation chamber adjacent the blood pump receives hydraulic actuation fluid from an actuator pump through a three-way ventricular dump valve to compress the blood pump during systole and eject blood therefrom. During diastole the actuation fluid is permitted to drain from the actuation chamber through the three-way valve into a reservoir.

Abstract: A cardiac prosthesis having a hydraulically actuated compressible blood pump. An actuation chamber adjacent the blood pump receives hydraulic actuation fluid from an actuator pump through a three-way ventricular dump valve to compress the blood pump during systole and eject blood therefrom. During diastole the actuation fluid is permitted to drain from the actuation chamber through the three-way valve into a reservoir. The valve includes inlet and outlet manifolds and synchronously movable valve members within each manifold for controlling the flow of actuation fluid into and out of the actuation chamber.

Abstract: A total cardiac prosthesis having a pair of hydraulically actuated compressible blood pumps. An actuation chamber adjacent each blood pump receives hydraulic actuation fluid from a separate actuator pump to compress the blood pump during systole and eject blood therefrom. During diastole the actuation fluid is permitted to drain from the actuation chamber into a reservoir. One of the actuator pumps delivers actuation fluid to its associated actuation chamber through a three-way ventricular dump valve, which directs fluid directly to the reservoir during diastole. The other actuator pump is a reversible pump which repeatedly reverses its pumping direction to effect systole and diastole in its associated blood pump.

Abstract: A cardiac prosthesis having a hydraulically actuated compressible blood pump. An actuation chamber adjacent the blood pump receives pulses of hydraulic actuation fluid from an actuator pump through a fluid inlet path to compress the blood pump during systole and eject blood therefrom. Between pulses the actuation fluid is permitted to drain from the actuation chamber through an outlet path into a reservoir. Discharge of fluid through the outlet path is controlled by a dump valve which is adapted to close or open the outlet path primarily in response to forces which vary as a function of the flow of actuation fluid through the fluid inlet path.

Abstract: A cardiac prosthesis having a hydraulically actuated compressible blood pump. An actuation chamber adjacent the blood pump receives pulses of hydraulic actuation fluid from an actuator pump through a fluid inlet path to compress the blood pump during systole and eject blood therefrom. Between pulses the actuation fluid is permitted to drain from the actuation chamber through an outlet path into a reservoir. Discharge of fluid through the outlet path is controlled by a dump valve which is adapted to close or open the outlet path primarily in response to forces which vary as a function of the flow of actuation fluid through the fluid inlet path.

Abstract: An intra-aortic balloon includes a flexible catheter having a deformable fitting closing one terminus and a connecting attachment at the other end. Adjacent the fitting, the catheter has a number of perforations all within an elongated balloon surrounding the perforations. One end of the balloon is secured to the fitting and at the other end is secured to the catheter. The connecting attachment is engageable with a removable body to which is secured a manually deformable wire extending through the catheter and into the fitting. The body has a duct open to the interior of the catheter and to the atmosphere. An outwardly opening check valve is in the duct.

Abstract: The engine comprises a base having a spool fastened thereon, the spool including a hub symmetrical about a first axis and having a pair of side plates normal to and having inside faces spaced apart along the first axis. There are plate ports in the inside faces. A cylinder rotor includes a second hub rotatable on the first hub about the first axis and includes a pair of side discs normal to the first axis and having outside faces spaced apart axially between said side plates to establish first and second axial clearances between the side plates and the adjacent side discs. There are cylinders mounted radially on the cylinder rotor with ducts extending from the cylinders to the disc ports in the outside faces radially opposite the plate ports. A driven shaft symmetrical about a second axis is eccentrically journalled in and extends through the hub. A rotor is fast on the driven shaft and carries pivot pins.

Abstract: A blood pumping system has a pair of integral flexible bodies each provided with an inlet and an outlet and disposed in open top cavities in a housing. The cavities have extensions holding inlet valves and outlet valves for opening and closing the inlets and outlets. A flexible diaphragm overlies the cavities and their extensions and is secured by a cover providing separate chambers over the inlet valves, the outlet valves and the bodies. Solenoid air valves are selectively energized to supply and exhaust the chambers to operate the valves and bodies. Switches responsive to the full and empty positions of the bodies govern the energization of the solenoids through control circuitry including a voltage controlled oscillator, a device for changing the frequency of the oscillator in accordance with the time of operation of at least some of the switches, and a device for ensuring at least a minimum rate of operation of the switches.

Abstract: A spirometer has a housing with a wall having an opening therein. A bag made up of a first, stiff sheet and a second, flexible sheet having an exhaust slit therein as well as an inlet tube is supported within the housing with the first sheet lying against the wall and with the inlet tube extending through the opening. A valve flap within the bag overlies the inlet tube and a valve bar in the housing is spring urged with a selected force to press the bag, between the slit and the tube, against the wall. A primary plate is hinged to the housing at its top to lie against the second sheet. A secondary plate is similarly hinged and is power controlled to be spaced from or to press against the primary plate through an intervening cushion. The position of the primary plate is indicated mechanically and also by electrical instrumentation.

Abstract: A volume ventilating respirator, especially for infant and pediatric use, has a pair of different size volume chambers with means for selecting one or the other for specific use. There is a selector affording a choice of several different ventilating modes including deep breaths at chosen periods or events. The operation is generally automatic with response to patient effort, if desired, and has some responses to manual signals; i.e. deep breath and inspiration. The operation is electric with pneumatic and electronic controls and logic and numerous event indicators and alarms.

Abstract: A respiratory humidifier has a base with a thermally controlled heater therein effective to heat a first transfer surface on the top of the base. Removably pressed against the first transfer surface is a second transfer surface forming the bottom of a container into which liquid is admitted, close to the bottom, by a float valve to establish a liquid level. Gas is admitted to the container below the liquid level through an inlet tube and is released from the container above the liquid level through an outlet tube. A porous pad in the container is in the gas flow path between the inlet tube and the outlet tube to provide extended, wettable surface. A float blocks the entrance to the outlet tube when the liquid level rises unduly and a normally closed shunt passage between the inlet tube and the outlet tube opens by differential pressure when the entrance to the outlet tube is blocked.

Abstract: A volume ventilator effective to give a patient successive inhalations and exhalations at timed intervals is responsive to the patient's effort to inhale and at selected times gives the patient a deep breath synchronized with the patient's effort to inhale.