Abstract: A clinical chemistry analyzer system for blood chemistry analysis is disclosed. Two major parts comprise the system. One part is a discardable sensor cartridge which contains a bank of sensors, calibration fluid containers, conduit means and an external peristallically pumpable tube section. The other part is an analysis machine which interfaces with the discardable cartridge and has means to drive the peristaltic pump as well as means to interface with the sensors of the cartridge to provide a readout therefrom. The system is adapted to be made part of a heart/lung machine sustaining a patient in order to sample and monitor the venous and arterial blood flow thereof.

Abstract: A hollow fiber membrane type artificial lung and a method for the manufacture thereof.

Abstract: A porous polypropylene hollow fiber membrane of a circular cross section 150 to 300 .mu.m in inside diameter and 10 to 150 .mu.m in wall thickness for use in an artificial lung, which hollow fiber membrane is characterized by having an inner surface aperture ratio in the range of 10 to 30%, a porosity in the range of 10 to 60%, and an oxygen flux in the range of 100 to 1,000 liters/min.m.sup.2.atm. and inducing no leakage of blood plasma within 20 hours use in the external circulation of blood therethrough.

Abstract: A cardiopulmonary system is disclosed which is intended for oxygenation of a patient's blood during heart surgery in which the patient's own lungs are used for such oxygenation. The cardiopulmonary system includes use of a blood reservoir which includes at least two chambers, one for venous blood collected from the patient's heart or a major vein and one for arterial blood, and include filters for filtering both the venous and arterial blood as they enter the respective chambers.

Abstract: In a hollow-fiber oxygenator consisting of a container containing a plurality of fibers joined into a bundle and open at their ends to allow the passage into them of a first fluid (blood) and over the outside of which flows a second fluid (oxygen-carrying gas) which diffuses between them, a diffuser for the second fluid is provided which consists of several arms disposed in an array and is introduced between the fibers in positions close to the terminal zone of the fibers themselves.

Abstract: This invention provides a means of measurement tissue pressure in muscle compartments and other regions in humans and other animals. An appropriate length, for example, 6 to 12 inches of thin plastic tubing, typically less than 3 mm outside diameters, is prepared as a working part of the tissue pressure transducer. A portion of the plastic tubing including the thin wall section such as a bubble is inserted into the muscle tissue for which pressure measurement is desired to be made. A fluid is circulated through the tubing at a constant flow rate. When the internal pressure of the tubing is greater than the external pressure, the bubble expands and there is no increase in the flow resistance of the system. When the pressure on the outside exceeds the normal system operating pressure, the thin wall section or bubble contracts, resistance to flow increases, and the system pressure increases. This increase in system pressure is directly proportional to tissue pressure.

Abstract: A removable U.V. light array assembly for use in a photoactivatable agent, patient treatment system wherein photoactivatable agents, in contact with patient blood cells, are irradiated extracorporeally and then returned to the patient.

Abstract: A unitary device for the treatment and collection of blood from two different sources during a surgical procedure comprises a hollow housing made of a rigid, preferably transparent, material, first and second blood inlets in the housing, a first blood treatment element inside the housing comprising a layer of porous defoaming material and a layer of non-woven depth filter material, and a second blood treatment element inside the housing comprising a layer of porous defoaming material and free of any depth filter material. The novel device also includes internal walls for providing two blood flow paths therein, one through the first inlet, the first blood treatment element, a blood collection reservoir defined within the device and a treated blood outlet in the bottom wall of the housing, and the other through the second inlet, the second blood treatment element, the blood collection reservoir and the blood outlet.

Abstract: A heat exchanger (38) is provided which may be used in a mass transfer device (20), such asn an oxygenator or a dialyzer. The heat exchanger comprises a core (40) formed of a corrugated metal having a high thermal conductivity. Each of the corrugations of the core comprises substantially parallel side walls (70, 72). A first fluid, such as blood, is introduced onto the outside of the core. A second fluid, such as water, is introduced into the inside of the core. The first and second fluids will be in heat exchange relationship with each other and the flow of the fluids is substantially uniform resulting from the substantially parallel side walls of the corrugations. The core is formed by providing a flexible metalhose, annealing the flexible metal hose, compressing the annealed hose and expanding the compressed hose to a length that is substantially less than its original length but greater than its length during compression.

Abstract: A liquid-gas bubble separator comrising a container having an inlet for a fluid which includes liquid and gas bubbles, an outlet and upstream and downstream vents. A filter element is provided in the container between the inlet and the outlet. The filter element permits the passage of the liquid and inhibits the passage of the gas bubbles. The filter element is between the upstream and downstream vents so that gas bubbles which do not pass through the filter element can be vented through the upstream vent, and any gas bubbles downstream of the filter element can be vented through the downstream vent. A bypass passage is provided around the filter element. A portion of the filtered fluid is recirculated through the bypass passage to prevent forward flow through the bypass passage when the filter element is clean, and such recirculating flow is terminated when the filter is clogged to a predetermined degree to thereby open the bypass passage for forward flow.

Abstract: A totally or partially implantable fluid delivery system actuated by a valveless piezoelectric drive system. The drive system may actuate an artificial heart by a hydraulic bladder or directly actuate a human heart. The drive system has an output with a frequency and displacement sufficient to directly drive a human or artificial heart and includes a control circuit for recapturing and reusing the power driving the piezoelectric drive system. An artificial heart which includes two check valves having a flexible valve element and supporting tabs on opposite sides.

Abstract: A mass/heat exchange device for use as blood oxygenator, dializer, heat exchanger and the like, includes a rectangular or cylindrical elongated housing with first and second opposite axial ends. The interior of the housing is subdivided into three chambers, including an inlet chamber located at one axial end, an outlet chamber located at the opposite axial end and a central mass/heat transfer chamber located therebetween. A plurality of parallel tubes extend through the central chamber and connect the inlet and outlet chambers to provide passageways for treating medium to flow therebetween. The outer surface of each tube has the shape of a series of spherical lobes, connected end-to-end. Further, adjacent tubes are offset from one another to allow internesting of their lobes in a tight orderly packed manner. The treating medium, for example oxygen, flows through the tubes while a medium to be treated, for example blood, flows through the interstitial spaces between the tubes.

Abstract: A membrane oxygenator includes an upper nested arrangement of a hard shell venous reservoir, a bowl-like defoamer within the reservoir and a heat exchanger coil vertically supported within the defoamer, and includes a membrane oxygenator unit mounted on the bottom of the upper arrangement. The oxygenator unit includes an inlet chamber with a tangential inlet providing swirling blood flow to dislodge air bubbles and centrifuge air to an upper center region of an inlet chamber where gas is exhausted through a vent. A bottom blood outlet chamber of the blood oxygenator unit has a relatively thin vertical cross-sectional area such that priming flow velocity therein discharges all air from the outlet chamber.

Abstract: A method for treating circulatory fluid constituents with an apparatus which includes a first switching device which connects the upstream side of a first circulatory fluid treatment device with a flow of circulatory fluid from a source, and a second switching device which connects the downstream side of the first circulatory fluid treatment device with a destination of the circulatory fluid.

Abstract: An improved structure for directing the flow of blood and blood foam onto a heat exchanger in a bubble blood oxygenator is disclosed. An extended skirt extends from the plate where venous blood and oxygen are mixed to the top of the heat exchanger of the blood oxygenator. Blood and blood foam flow downwardly uniformly over the mixing plate and evenly onto the heat exchanger. Full utilization of the heat exchanger may thereby be more easily achieved.

Abstract: An immunoadsorbent material for removing IgG and IgG-complexes from biological fluids is prepared by covalently binding protein A to a solid-phase silica matrix. It has been found that particularly stable, high-capacity immunoadsorbents are obtained by derivatizing the silica with amino and/or carboxyl groups, and reacting the protein A with a carbodiimide at a pH in the range from 3.5 to 4.5. Binding through free hydroxyl groups may be achieved with cyanogen halides at a pH in the range from 11.0 to 11.5. After acid washing (pH 2.0-2.5) to remove non-covalently bound protein A, the immunoadsorbent may be employed in a column for therapeutic treatment of various cancers and autoimmune disorders where IgG-complexes are implicated as suppressing factors in inhibiting a normal immune response.

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: In a blood reservoir comprising a hollow housing and filtration/defoaming and blood collecting sections therein; the blood collecting section is located below and separated from the filtration/defoaming section receiving bubbled blood and has a sufficient capacity, typically 500 to 2,500 ml, to keep blood collected therein out of contact with the filtration/defoaming section; guide means in the form of a cone-shaped deflector is disposed between the filtration/defoaming section and the base of the housing to lead along its inner surface defoamed blood from the filtration/defoaming section to the collecting section without dripping.

Abstract: A blood oxygenator comprising a housing generally in the form of a box and bundles of hollow fibers of semipermeable membrane set therein for effecting gas exchange therethrough. In this blood oxygenator, each end of each bundle of hollow fibers of semipermeable membrane is secured together by potting material in such a way as to allow their open ends to communicate separately with a gas inlet and a gas outlet; the space around the bundles of hollow fibers of semipermeable membrane communicates with a blood inlet and a blood outlet; the blood-gas contact chamber within the housing is divided into a plurality of compartments with the interposition of blood flow channels narrowed by baffles; and the bundle of hollow fibers of semipermeable membrane is disposed in the contact chamber so as to be substantially parallel to the baffles.

Abstract: A medical device with a heat exchanger portion comprising a coiled, corrugated, flattened tube located in a flowpath provided between coaxial cylindrical walls, the tube having a cross sectional configuration including a length smaller in a first direction perpendicular to the axis of the inner and outer walls than in a second direction perpendicular to the first direction.

Abstract: An apparatus for the autotransfusion of blood or similar body fluid. The apparatus includes a container which is an evacuable, vacuum-stable container having a bottom part and a cover part. The container also includes an inlet opening for the body fluid arranged in the cover part. An outlet opening for the body fluid is arranged in the cover part with a screen covering the outlet opening. An opening is arranged in the bottom part for the production of a gas flow connection to a chamber with a gas pressure different from that of the inside of the container. A membrane deformable by pressure, and through which the body fluid cannot pass is held at the edge between the bottom and the cover parts. The membrane divides the container into a gas-filled bottom chamber and a cover chamber sealed off from the latter to receive the body fluid. A float seals off the outlet opening.

Abstract: An apparatus for extracorporeal lung assist including a pump device having a flexible blood reservoir housed in a rigid housing, which pump device is able to expand and contract the blood reservoir by pumping liquid into and from the housing, thereby repeating cycles of blood feed and blood take-off, a blood take-off circuit connected to the in-flow side of a membrane artificial lung and in which the pump device is disposed, a blood feed circuit connected to the out-flow side of the membrane artificial lung, the two circuits forming an extracorporeal circulation circuit, a liquid circulation circuit connected to the housing of the pump device and having a flexible liquid reservoir disposed therein with a head provided relative to the pump device, and sensors for detecting the expansion and contraction of the liquid reservoirs, whereby blood in-flow and out-flow paths are controlled so that when the blood reservoir is contracted, blood is drawn into the blood reservoir under subpressure in the housing, whereas

Abstract: A venous reservoir is provided in which a blood inlet (42) is located at an inlet end (70) of the container (48) which extends upwardly with a fast rise and for a sufficient distance to allow the blood entering the inlet to enter a large volume and to expand rapidly. The top (74) of the inlet end wall (70) of the container communicates with a vent outlet (46) whereby a sharp decrease in the velocity of the blood flow resulting from its rapid expansion provides buoyancy to air in the blood causing air bubbles to rise to the top of the container and be vented through the vent opening. A top wall (76) of the container extends from the vent opening and toward a blood outlet (44), with the top wall being curved in a manner to prevent the velocity of blood from increasing until the blood is substantially at the blood outlet.

Abstract: A unitary device for the treatment and collection of blood from two different sources during a surgical procedure comprises a hollow housing made of a rigid, preferably transparent, material, first and second blood inlets in the housing, a first blood treatment element inside the housing comprising a layer of porous defoaming material and a layer of non-woven depth filter material, and a second blood treatment element inside the housing comprising a layer of porous defoaming material and free of any depth filter material. The novel device also includes internal walls for providing two blood flow paths therein, one through the first inlet, the first blood treatment element, a blood collection reservoir defined within the device and a treated blood outlet in the bottom wall of the housing, and the other through the second inlet, the second blood treatment element, the blood collection reservoir and the blood outlet.

Abstract: A blood oxygenator of the outside perfusion type using hollow fibers as the gas exchange membrane. In this blood oxygenator, a plurality of contact chambers each containing a bundle or bundles of hollow fibers for gas exchange use and communicating with a blood inlet and a blood outlet are disposed to make blood flow in multiple paths within a housing, and each bundle of hollow fibers is arranged so as to be substantially perpendicular to the direction of blood flow. In spite of its compact construction, this blood oxygenator has high oxygen and carbon dioxide exchange rates per unit of membrane even when used in the gas exchange of blood having high flow rate, exhibits only a small pressure loss, and causes little channeling of the blood and gas. Moreover, it is easy to manufacture because of its relatively simple structure.

Abstract: Method and apparatus for the oxygenation of the blood. The apparatus (14) includes a hollow membrane (16) having a central tubular portion (32) and a plurality of radially outwardly extending diffusion elements (34). The membrane is disposed within a sheath (18) and both are supported by a flexible wire (20), one end of the membrane and sheath being secured to the wire. The other end of the membrane and sheath are secured to a tube (22) through which oxygen may be supplied to the hollow membrane. The sheath and membrane may be twisted upon the wire (20) to facilitate insertion and, once inserted, they may be untwisted to resume their operable position.

Abstract: Full-flow cardiac assist is provided for cardiogenic shock patients without major surgery by a miniature axial-flow pump which can be inserted into the heart through the femoral artery and driven via a flexible cable from an external power source. The cable is contained within the catheter attached to the pump. The catheter also provides a conduit to supply the pump bearings with a blood-compatible purge fluid at a rate and pressure sufficient to prevent thrombus formation and introduction of blood elements between rotating and stationary elements of the pump. Due to the very small diameter of the pump, rotational speeds on the order of 10,000 to 20,000 rpm can be used to produce a blood flow on the order of about four liters per minute without significant hemolysis.

Abstract: A blood oxygenating device having an oxygenating chamber and a heat exchanger chamber. The oxygenating chamber consists of a bubbler chamber and a mixing chamber. Oxygen is introduced into the bubbler chamber through a porous diffusion means situated near the inlet of the bubbler chamber. Bubbles pass from the bubbler chamber into a mixing chamber which is provided with a plurality of secondary flow-producing deflectors to promote secondary flow of blood bubbles passing therethrough. The secondary flow results in a highly efficient oxygen-carbon dioxide transfer. The blood bubbles are then passed through a heat exchange chamber and a defoaming means prior to exiting the oxygenating device.

Abstract: An artificial heart or heart strengthening device to simulate the natural heart pulsation of mammals by electromagnetic means which may operate alone or in conjunction with the natural heart.

Abstract: A method and apparatus are disclosed for treating a patient by removing immunoreactive substances from the patient's blood using microbial ligands such as Staphylococcus Protein A. The method of the present invention comprises removing blood from the patient, separating the removed blood into plasma and cellular components, passing the plasma component through an immunoadsorbent material to produce a treated plasma component, and returning the treated plasma component and the cellular component to the patient. The immunoadsorbent material comprises a microbial ligand such as Staphylococcus Protein A, or components thereof, covalently bonded to an inert and nondegradable support. The removing, separating, passing and returning steps are performed substantially continuously and simultaneously with one another.

Abstract: A method and system are disclosed for externally treating human blood, with the objective of reducing the functioning lymphocyte population in the blood system of a human subject. According to the method, blood is withdrawn from the subject and passed through an ultraviolet radiation field in the presence of a dissolved photoactive agent capable of forming photo-adducts with lymphocytic-DNA, mobile hormonal hormonal receptors or antigen sites to thereby effect covalent bonding between the photoactive agent and the same, thereby inhibiting the metabolic processes of the lymphocytes or complexing them; and thereupon returning the irradiated blood to the subject. The withdrawn blood may be formed into an extracorporeal stream and flowed through a treatment station whereat the irradiation is effected, as for example by exposure to UV radiation; and such flow process may be conducted on a continuous basis.

Abstract: A method and system are disclosed for externally treating human blood, with the objective of reducing the functioning lymphocyte population in the blood system of a human subject. According to the method, blood is withdrawn from the subject and passed through an ultraviolet radiation field in the presence of from about 1 nanogram to 100 micrograms per ml of blood, of a dissolved photoactive agent capable of forming photo-adducts with lymphocytic-DNA, mobile hormonal receptors or antigen sites to thereby effect covalent bonding between the photoactive agent and the same, thereby inhibiting the metabolic processes of the lymphocytes or complexing them; and thereupon returning the irradiated blood to the subject. The withdrawn blood may be formed into an extracorporeal stream and flowed through a treatment station whereat the irradiation is effected, as for example by exposure to UV radiation; and such flow process may be conducted on a continuous basis.

Abstract: A fully portable, semi-automatic mechanical heart-lung substitution system and method. The system includes a venous cannula adapted for insertion into the vena cava of the patient and an arterial cannula adapted for insertion into the right and/or left common carotid artery of the patient. The venous cannula is attached to a roller pump used to pump blood from the patient's right heart to a membrane oxygenator. The speed of the roller pump is automatically controlled by means of a pressure sensor that is attached to the outer wall of the venous cannula so as to sense the internal venous blood pressure inside the patient's vena cava. Blood flows from the oxygenator to a compliance reservoir which expands so as to create increasing pressure within the reservoir as the volume of blood filling the reservoir increases.

Abstract: In combination with a blood reservoir, a blood volume detecting apparatus is used to ensure safe operation of the reservoir which includes a conduit in fluid communication with a lower part of said blood reservoir, a diaphragm associated with the other end of the conduit and movable by a differential hydraulic pressure applied by the blood through the conduit, and means for detecting the swelling and contracting movement of the diaphragm.

Abstract: A rotary piston pump for the displacement of blood has a single-lobe trochoidal surface along the peripheral wall of a housing and an eccentrically displaced rotary piston having a pair of opposite edges confronting this surface. The edges confronting the surface are rounded of circular arc curvature with a radius less than the equidistant between the theoretical epitrochoid of the orbits of these edges and the surface. A gap seal is thus provided which prevents damage to blood vessels when the pump is used for the circulation of blood, e.g. in an artificial heart.

Abstract: A hemocompatible flexible diaphragm and flexible wall pumping chamber positioned in a rigid body and actuated by alternating positive and negative fluid pulses. An inlet valve and an outlet valve are integrally molded in the pumping chamber. The diaphragm and pumping chamber are preferably molded of an elastomer. The pump is atraumatic, inexpensive and the pumping chamber and diaphragm are disposable.

Abstract: A blood filter such as may be used in a cordiopulmonary bypass system includes a housing having upper and lower chambers with a cylindrical filter element disposed in the lower chamber. The inlet to the housing is in the upper chamber, which is upstream of the lower chamber, and the outlet is through the lower chamber and communicates with the interior of the filter element. Thus, blood enters the upper chamber and flows to the lower chamber where it passes through the filter element from the outer side to the interior to remove microemboli such as gas bubbles, fat emboli and agglomerates, the filtered blood exiting through the outlet. In order to remove a substantial amount of the gas in the blood, and particularly gross bubbles, upstream of the filter element, the upper chamber is cylindrical and the inlet directs the blood tangentially to flow around the periphery of the chamber.

Abstract: A cardioplegia system in which cardioplegia medication or a mixture of arterial blood and medication is delivered to the heart of a patient undergoing open heart surgery, which includes a bubble trap in conjunction with the delivery system. The bubble trap separates bubbles from the cardioplegic solution and when formed at least partially of transparent material, provides a visual indication of the air removed from the infusion liquid.

Abstract: A blood defoamer for use in surgical procedures is disclosed comprising a porous defoaming element, a non-porous end piece in contact with a surface of the defoaming element, and a layer of fabric affixed to the end piece adjacent to said surface. Bypass of blood flow around the layer of fabric, which is situated downstream of the defoaming element, and accumulation of bubbles in the defoamed blood reservoir are prevented by bonding a suitably configured retaining ring to the end piece with a portion of the layer of fabric held in a fluid-tight seal between the end piece and the retaining ring.

Abstract: An actuator is described for use in a pump having a pump chamber whose contents are expelled by movement of a pair of pusher plates toward one another. The actuator includes opposed solenoid armatures which are operable for movement between open and closed positions. The armatures are each operatively connected to an associated pusher plate by a main spring which is attached at one end to the back end of the armature, extends through a front-to-back slot in an armature core, and is connected at its opposite end to the pusher plate. A pair of preload springs carried on each armature and disposed on either side of the associated main spring acts to hold the main spring in a prestressed condition prior to solenoid actuation.

Abstract: An autotransfusion apparatus for blood or a similar body fluid, comprising(a) an evacuatable vacuum-resistant container (5) having a bottom part (4) and a cover part (3), with(a1) an inlet opening (20) for the body fluid arranged in the cover part,(a2) an outlet opening (24) for the body fluid having a screen (25) covering the outlet opening, and(a3) an opening (9) for producing a gas-flow connection to a space having a gas pressure which differs from the inside of the container.

Abstract: A chamber structure in a blood pump or the like is described. The structure includes a deformable sac having an annular side wall which is held in a rigid condition, and a pair of opposed circular walls, each joined to the annular side wall through a flexible annular wall portion. A circular pusher plate acting against each circular wall has an initial deflection position at which the associated flexible wall portion in the sac takes the form of a circumferentially uniform roll having an outwardly convex, bulged cross sectional curvature. The rolls in the sac maintain their circumferentially uniform, bulge-like character as the pusher plates are moved toward inwardly moved positions.

Abstract: A system for autotransfusion has an aspirating wand or tube coupled to a vacuum source through a reservoir for receiving aspirated blood. From that reservoir blood flows to a receiving bag in a relatively low position below the elevation of the patient. When there is sufficient blood supply in the bag, the bag is elevated from its lower position to a point higher than the patient. Blood then flows from the elevated bag by gravity through a conducting tube and a needle into the patient. When the bag is then substantially empty, it is again lowered to an elevation lower than the patient for repetition of the operation. If desired, an anticoagulant can be introduced into the aspirated blood.

Abstract: A pump adaptable for use as a human heart includes first and third pump chambers separated from an intermediate second chamber which may house a motor. The chambers are separated by diaphragms which may be alternately driven. A pump is achieved which needs no venting. Each of the first and third chambers can pump blood in operation and can be connected in series or separately to the ventricles of the heart.

Abstract: A circulatory assistance device for implantation in the human body to assist a failing heart. The device comprises a truncated conical structure, made up of rigid pieces connected by volumetric reduction columns which contain electromechanical means for exerting alternating stress and mechanical means for maintaining the stress. On the inside of the structure are positioned sacs belonging to a double, right and left, hydraulic drive unit comprising pumping means. The truncated conical structure further comprises fastenings for securing the structure in implanted relation in a human body. The structure is connected, by a multiconductor cable to an implantable electric power source and to electronic control means which govern the functioning chronology of the alternating stress and of the double hydraulic drive unit.

Abstract: An improved hemodialysis method (which may optionally include a hemoperfusion step) including regional extracorporeal citrate anticoagulation is disclosed which permits complete elimination of conventional heparin treatment and possible consequent medical complications from heparin use. The method preferably comprises removing blood from a patient at a level of at least about 80 milliliters per minute, infusing citrate anticoagulant into the blood at a level of up to about 10 millimoles of citrate anion per liter of blood, treating the blood (e.g., by dialysis and hemoperfusion if desired), thereafter infusing a calcium compound into the blood to restore proper calcium ion level and coagulative properties, and returning the blood to the patient. A calcium-free acetate or bicarbonate dialysate is advantageously employed. A charcoal perfusion filter can optionally be used in conjunction with the dialyzer apparatus.

Abstract: A yoke shaped collapsible blood reservoir having first and second yoke legs joined by a yoke midsection. A filter element is positioned in the yoke midsection and across the blood flow path between an inlet at the base of the first yoke leg and a blood outlet at the base of the second yoke leg. An angular blood inlet and a gradual increase in cross-sectional area from the blood inlet to the yoke midsection decreases turbulence and assists in bubble separation.

Abstract: Novel methods and apparatus are provided for regulating the concentrations of oxygen and carbon dioxide in blood during extracorporeal cardiopulmonary bypass. According to the invention, probes capable of measuring the partial pressures of oxygen and carbon dioxide in blood are provided in the venous and arterial lines, both probes measuring the blood gas levels at the ambient temperature of the blood in the extracorporeal blood circuit. These concentrations are monitored on a real-time basis by a processor unit which compares the values reported by the arterial probe with selected values chosen by the perfusionist. The processor unit then preferably controls the gas flow to the oxygenator portion of the perfusion system so that the treated blood maintains the chosen concentrations of oxygen and carbon dioxide. In other embodiments, the probes are adapted to measure other perfusion variables, including temperature, hematocrit, blood flow rate, and pH, thus allowing further automation by the processor unit.

Abstract: A unitary system incorporates an upper reservoir container having a blood gas separator, a cardiotomy reservoir and a venous reservoir. The upper container is positioned directly above a lower mass transfer container coupled with the venous reservoir by means of a check valve and having a spirally wound flattened tubular transfer membrane. A vacuum is drawn upon an upper portion of the reservoir container which carries a blood gas separator into which aspirated wound site blood is drawn for filtering and collection of blood in the cardiotomy reservoir. The latter is automatically drained via a pressure responsive valve into a venous blood reservoir at the lower portion of the reservoir container and into which venous blood flows for mixing with the filtered cardiotomy blood.

Abstract: A hemodialysis system capable of operation in either a single needle mode or a double needle mode includes an arterial blood pump which is the sole blood pump in the system during the double needle mode. For single needle mode operation a venous blood pump is employed to return blood to the patient. A pump speed control adjusts the speed of the arterial pump in the double needle mode, and the speeds of both blood pumps in the single needle mode. A controller continuously operates the arterial pump in the double needle mode, and alternately activates the two pumps in the single needle mode. A module for modifying a commercially available double needle system for operation in either of the two modes is also described.