Searle Cardio-pulmonary Systems Inc.

Foxcroft Associates

Thoratec Laboratories Corporation

Other

Davol Inc.

Electromedics, Inc.

Rasor Associates, Inc.

Thomas C Robinson

Sotiris Kitrilakis

Thomas P Sahines

Thomas B Martin, Jr

Robert K Fernandez

Augustus Felix

Gary D Reeder

Craig S Nevers

Keith Evan Buck

Arthur M Bobrove

Timothy Appleby

David John Farrar

Klaus J Cross

A blood processing system is described in which blood pressure readings obtained before and after passage of blood aspirated from an operative site through a membrane separator is used by a programmed controller to determine the hematocrit level of the blood and to add saline solution to adjust the hematocrit level to a desired level. The blood processing system contains a distributor cap to distribute wash solution to the inside of a filter to wash out additional blood cellular material within the filter. A precollector may be used remotely from the site of the blood processing system and later joined with the system to withdraw blood contained in the precollector for processing by the blood processing system.

Blood pumping and processing system

A hypodermic needle assembly is described which automatically covers the pointed end of the needle after the assembly is used in order to prevent accidental punctures. A sheath circumscribes the needle and is held a patient's tissue to allow sliding movement of the sheath over the needle pointed end, and preferably locking of the needle within the sheath, as well, when the needle is withdrawn from the patient.

Automatic sheath protection of hypodermic needle

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. The microporous and solid walled fibers may be woven in layers which are laminated to form a predetermined mat thickness separated by layers with only parallel fibers of a single set in each layer.

Gas transfer apparatus

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.

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.

Arterial graft prosthesis

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. The control device further includes first and second ejection rate controllers which generate control signals to adjust the ejection rates of the dominant and subordinate ventricles in accordance with adjusted heart rate so the dominant and subordinate ventricles can eject all blood in the time allowed by the adjusted heart rate. The control signals are supplied to pump motors to contro the operation of pump motors which in turn drive the actuation device to eject blood from the ventricles.

Electronic control system for a cardiac prosthesis

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.

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.

Engine

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.

Hydraulically actuated cardiac prosthesis with three-way ventricular

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.

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.

Hydraulically actuated total cardiac prosthesis with reversible pump and

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.

Hydraulically actuated cardiac prosthesis

Hydraulically actuated cardiac prosthesis and method of actuation

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.

Intra-aortic balloon

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. There are pistons in the radial cylinders and connecting rods pivoted in the pistons and pivoted on the pivot pins. On the rotor are some spacing pins carrying eccentrics. Eccentric strap bearings extend around the eccentrics and are secured to the spool. There are separate, constant volume oil pumps appropriately driven, each being connected to a respective one of the axial clearances in order to maintain the dimensions and shapes of the clearances such that gas leakage therethrough from the ports toward the atmosphere is maintained at a predetermined minimum value.

Growing community of inventors

Berkeley, CA, United States of America

Thomas C Robinson