Abstract: A mock circulation system is provided including a collapsible housing having a plurality of channels formed therein so as to represent the arteries, veins and organs of a human circulatory system. A pair of artificial ventricles are connected to the housing and pump fluid through the housing so as to develop circulation within the housing. By using a plurality of flow-restricting devices, and by modifying the pumping of the artificial ventricles, a variety of circulatory conditions (both healthy and pathogenic) can be simulated within the system. In accordance with the principles of the invention, cardiac massage may be demonstrated by manually squeezing the artificial ventricles. In accordance with another principle of the invention, Starling's Law Curves may be generated to show that cardiac output is determined by venous pressure.

Abstract: A method for providing ventricular assist to a patient with a weak or nonfunctional heart includes attaching an artificial ventricle to a patient and pumping said artificial ventricle with a muscle powered hydraulic pump. This method is enhanced by supplementing said artificial ventricle as needed with a pneumatic pumping system which is hermetically sealed from the hydraulic fluid. The hydraulic pumping power is amplified by driving a first pumping member of larger dimension against a second pumping member of smaller dimension to thereby supply increased force to overcome existing blood pressure.

Abstract: A total artificial heart for placement inside a living body comprising right and left ventricle enclosures, wherein each ventricle includes an exterior wall formed of (i) contacting wall structure and (ii) noncontacting wall structure which collectively enclose an interior volume comprised of a blood chamber and a pumping chamber. The contacting wall structure of each ventricle enclosure is configured for intercontacting relationship wherein the contacting walls of the respective ventricles form a septum which structurally separates the interior volume of the right ventricle from the interior volume of the left ventricle. The noncontacting wall structure comprises the remaining exterior wall of each ventricle enclosure. A fluid drive motor capable of reversible flow is positioned within and circumscribed by the septum and includes a flow channel therethrough which communicates between the respective pumping chambers of the right and left ventricle enclosures.

Abstract: A ventricle assist device for placement within a living body and including a self contained drive motor for generating pumping action with respect to a hydraulic pumping fluid. The ventricle assist device includes a ventricle having a blood chamber and a pumping chamber and an interconnect means coupled to the pumping chamber of the ventricle for receiving and displacing hydraulic fluid. A separate volume displacement chamber is attached to the interconnect means and provides a reservoir for excess hydraulic fluid for storage during diastole. A fluid pump and drive motor is positioned within the volume displacement chamber and connected at the interconnect means to supply the required pumping action for transfer of hydraulic fluid to and from the pumping chamber. Placement of the fluid pump and drive motor within the volume displacement chamber provides enhanced dissipation of heat from the energy conversion system and improved performance and durability.

Abstract: An artificial ventricle for use as part of a total artificial heart for implantation within a living being as part of its circulatory system. The ventricle includes a soft and flexible blood pumping sac which can be collapsed to the substantially flattened, squeezed or rolled-up structure of much reduced size. The sac includes inlet and outlet ports to permit the flow of blood therethrough and is contained within a semi-rigid and removable enclosure which provides pumping means for driving blood flow through the ventricle. The semi-rigid shell includes open and closed configurations to allow emplacement of the shell around an attached ventricle already sutured in place as part of the circulatory system. Removal of the rigid shell is likewise feasible without disturbing the attached ventricle.

Abstract: A ventricular assist device and a method of manufacturing the ventricular assist device. The device is generally flat in shape and gently curved so that it may be comfortably implanted under the skin or inside the chest of a patient. The device includes a housing comprising an atrial blood chamber, an atrial compliance chamber, a ventricular blood chamber and a ventricular pjmping chamber. Blood is introduced through an inlet port into the atrial blood chamber. An atrial compliance membrane within the housing separates the atrial blood chamber from the atrial compliance chamber and responds to the changing volume of blood. The ventricular blood chamber receives the blood from the atrial blood chamber through a flap valve which is formed as an integral extension of the compliance membrane.

Abstract: The present invention provides an improved method for treating blood to remove foreign substances such as immune complexes and free antigen. This is advantageously accomplished by separating a portion of a patient's blood as plasma, and acidifying the plasma to a pH below about 3.1 in order to cause the immune complexes to dissociate into antigen and antibody. After removing the antigen, the plasma is returned to the patient. Preferably, the patient's blood is substantially diluted prior to plasma separation, thereby substantially increasing the clearance rate of the plasma separator device and also washing off antigens bound to cellular blood components. Also, it is preferred that the plasma fraction is further diluted during the acidification step. Subsequent removal of excess fluid will cause substantial removal of free antigen. In a presently preferred process, the excess fluid volume is reduced by use of an ultrafiltration device capable of passing antigen, but not larger protein constituents of plasma.

Abstract: An artifical heart valve having thin, seamless leaflets which converge to the center of a frame from the frame's inner wall. The leaflets each have a convex outflow surface and a concave inflow surface. The leaflets meet along adjacent edges to form cusps. Sinus valsalvae sections of the valve are formed as rounded recesses defined in the valve frame's inner wall as continuous curved profiles of the respective leaflet concave surfaces. The valve is fabricated by vacuum molding techniques whereby layers of elastomer are vacuum formed to comprise the leaflet and sinus valsalvae portions. In one embodiment, the leaflets are all formed from two or more layers of elastomer which are cut to define the leaflet edges or commissures. One elastomer layer extends along the frame recess to provide continuity for each leaflet and its valsalvae. The resulting structure has no rims or seams in the inflow or outflow paths.

Abstract: An artificial heart valve having thin, seamless leaflets which converge to the center of a frame from the frame's inner wall. The leaflets each have a convex outflow surface and a concave inflow surface. The leaflets meet along adjacent edges to form cusps. Sinus valsalvae sections of the valve are formed as rounded recesses defined in the valve frame's inner wall as continuous curved profiles of the respective leaflet concave surfaces. The valve is fabricated by vacuum molding techniques whereby layers of elastomer are vacuum formed to comprise the leaflet and sinus valsalvae portions. In one embodiment, the leaflets are all formed from two or more layers of elastomer which are cut to define the leaflet edges or commissures. One elastomer layer extends along the frame recess to provide continuity for each leaflet and its sinus valsalvae. The resulting structure has no rims or seams in the inflow or outflow paths.

Abstract: A ventricular assist device and a method of manufacturing the ventricular assist device. The device is generally flat in shape and gently curved so that it may be comfortably implanted under the skin or inside the chest of a patient. The device includes a housing comprising an atrial blood chamber, an atrial compliance chamber, a ventricular blood chamber and a ventricular pumping chamber. Blood is introduced through an inlet port into the atrial blood chamber. An atrial compliance membrane within the housing separates the atrial blood chamber from the atrial compliance chamber and responds to the changing volume of blood. The ventricular blood chamber receives the blood from the atrial blood chamber through a flap valve which is formed as an integral extension of the compliance membrane.

Abstract: An implantable catheter for subcutaneous placement defining a tubular member which carries an enlarged, hollow, needle-pierceable member on one end thereof. The enlarged hollow member is implanted under the skin. The catheter defines a pair of angled turns, each of the angled turns occupying a plane which defines approximately a 90 degree angle to the plane of the other angle. This permits the enlarged portion of the catheter to be horizontally positioned subcutaneously, relative to an erect patient, while the end of the tubular catheter extends to its desired location in the peritoneal cavity.