Abstract: A small diameter surgical tool implements an agonist-antagonist deflectable joint. The deflectable joint is an actuatable bendable structure that uses push-pull, agonist-antagonist action of a pair of nested tubes to actuate the joint. The tubes are designed to have non-central, offset neutral axes, and they are fixed together at locations distal to the deflectable joint, such as at their distal ends. Axial translations of the tubes relative to each other causes a push-pull, agonist-antagonist action between the tubes, which causes the deflectable joint to bend. In one implementation, a deflectable joint can be created in nested tubes by configuring radial portions of the tube sidewalls extending along the joint to have an axial region of reduced stiffness. As a result, axial agonist-antagonist motion between the tubes can cause bending of the deflectable joint.

Abstract: A peritoneal dialysis system includes a base peritoneal dialysis system and a peritoneal dialysis fluid exchange system that operates independently of the base system. The base system includes a first cassette including a first patient line configured to be connected to a patient, and a PD cycler. The PD cycler receives the first cassette, and includes a pump that cooperates with the first cassette to deliver dialysate to and drain dialysate from a peritoneal cavity of the patient via the first patient line. The peritoneal dialysis fluid exchange system includes a second cassette including a second patient line configured to be connected to the patient and a fluid exchange device that receives the second cassette. The fluid exchange device includes a data exchange interface operable to transfer patient treatment data from the peritoneal dialysis fluid exchange system to the base peritoneal dialysis system.

Abstract: A dual reservoir access port includes a base having proximal and distal fluid reservoirs. The fluid reservoirs each comprise a bottom and a side wall. A dual prong outlet stem projects from a distal end of the base and comprises a first prong and a second prong. A first fluid channel extends through the first prong to the distal reservoir, and a second fluid channel extends through the second prong to the proximal fluid reservoir. A puncture shield is disposed between at least a portion of the second fluid channel and the bottom of the distal fluid reservoir. A needle-penetrable septum is disposed atop of each of the fluid reservoirs. A cap is placed over and around the port base compressing and sealing the septa against the base. A locking collar may be placed over a dual lumen catheter to lock the catheter to the dual prong outlet stem.

Abstract: Illustrative embodiments of diaphragm pumps, and pre-charging systems for use with such pumps, are disclosed. In at least one illustrative embodiment, a diaphragm pump may comprise a first diaphragm that separates a cavity into a motive fluid chamber and a pumped media chamber, a charge chamber having a controlled volume, wherein the controlled volume is adjustable to vary a controlled mass of compressed fluid capable of being stored in the charge chamber, and one or more valves configured to (i) fluidly couple the motive fluid chamber to an exhaust chamber during a first stroke period, (ii) fluidly couple the charge chamber to a compressed fluid inlet during at least a portion of the first stroke period, and (iii) fluidly couple the charge chamber to the motive fluid chamber during a second stroke period.

Abstract: A hydro-pneumatic system has an air powered motor driving a hydraulic pump with a pressure limiting valve that turns off air flow to the air motor when a hydraulic pressure output by the pump at a sense port of the valve reaches a certain limit. A valve element of the valve has spring, hydraulic and pneumatic sections, with an unbalanced area of the hydraulic section in a sealed pressure chamber of a cartridge that is part of the valve housing. The pneumatic section extends out one end of the cartridge to fill a bore between the air inlet and outlet ports when the pneumatic section is extended, and allow air to pass when it is retracted.

Abstract: It is an object to provide a composition in which an anthracene derivative is dissolved and a technique in which a thin film that has a favorable film quality is formed by a wet process using the composition. In addition, it is another object to manufacture a highly reliable light-emitting element using the composition at low cost with high productivity. A composition having a solvent and an anthracene derivative having one anthracene structure and one carbazolyl group which is bonded to the anthracene structure directly or through a phenyl group is formed. A thin film with a favorable film quality can be formed by a wet process using the composition. Accordingly, a highly reliable light-emitting element can be manufactured using such a thin film.

Abstract: A method of supplying air to an air spring biasing one of an intake valve and an exhaust valve of an internal combustion engine to a closed position is disclosed. The method includes: driving an air compressor with a motor prior to starting of the internal combustion engine, the air compressor fluidly communicating with the air spring to supply air to the air spring; determining that a predetermined condition has been reached; starting the engine once the predetermined condition has been reached; and driving the air compressor with a rotating shaft of the engine once the engine has started.

Abstract: A diaphragm vacuum pump has an electrically operated drive unit and a vacuum diaphragm, which separates a pump chamber into a drive-side part and a drive-remote part and which can be deflected by means of a movable part of the drive unit. The drive unit is an electromagnetic drive unit and the vacuum diaphragm is deflected in the direction of a linear movement generated electromagnetically in the drive unit. Preferably, a ventilation valve is also actuated the movable part. The vacuum pump is relatively small and compact and operates quietly. The vacuum pump is suitable in particular for “hands-free” applications of breastpumps.

Abstract: A hydro-pneumatic system has an air powered motor driving a hydraulic pump with a pressure limiting valve that turns off air flow to the air motor when a hydraulic pressure output by the pump at a sense port of the valve reaches a certain limit. A valve element of the valve has spring, hydraulic and pneumatic sections, with an unbalanced area of the hydraulic section in a sealed pressure chamber of a cartridge that is part of the valve housing. The pneumatic section extends out one end of the cartridge to fill a bore between the air inlet and outlet ports when the pneumatic section is extended, and allow air to pass when it is retracted.

Abstract: This invention provides a chemical supply system for supplying chemical solution from a chemical tank. The chemical supply system includes a chemical supply pump, a pressure adjuster configured to suction the chemical solution into the pump chamber by setting the pressure of working gas to a suction pressure, a switching controller configured to switch the suction-side opening-closing valve to the open state for starting to fill the pump chamber with the chemical solution, a pressure detector configured to detect at least one of a gas pressure in a space connected to the working chamber and a gas pressure in the working chamber when the suction-side opening-closing valve is switched to the open state and starts an inflow of the chemical solution to the pump chamber, and a suction controller configured to control the suction pressure applied to the working chamber by the pressure adjuster, based on a detection result of the pressure detector.

Abstract: An air motor includes ceramic valves and valve plates to enhance performance and efficiency of the air motor.

Abstract: An air motor for a pump assembly including a drop tube communicating between an upper chamber port and a top plate port and including a longitudinal axis that is at an angle of between about 0° and 10° with respect to each of the upper chamber longitudinal axis and the top plate port longitudinal axis. The drop tube has a substantially constant internal diameter, a first generally bulbous end, a second generally bulbous end, and first and second slots defined in the respective first and second bulbous ends. First and second seals are positioned in the respective first and second slots, and the first and second seals air-tightly seal an outer surface of the drop tube within the upper chamber port and the top plate port.

Abstract: An internal combustion engine has at least one intake valve and at least one exhaust valve. A first spring biases the at least one intake valve to a closed position. A second spring biases the at least one exhaust valve to a closed position. At least one of the first and second springs is an air spring. An air compressor fluidly communicates with the air spring to supply air to the air spring. The air compressor is operatively connected to a rotating shaft of the engine to be selectively driven thereby. A motor is operatively connected to the air compressor to selectively drive the air compressor. A method of supplying air to the air spring of the above engine is also disclosed. A method of supplying air to an air spring of an engine having both a mechanical and an electrical air compressor is also disclosed.

Abstract: Motorized single-machine multi-pump apparatus and closed-loop methodology interconnected with a gas pipeline at a natural gas production well, using pressurized gas flow and differential pressure to drive a pumping system regulated by pneumatic controls using self-generated clean, low-pressure instrument air. The apparatus is connected to the gas flow line and the outlet is connected back into the gas flow line at lower pressure, creating a differential pressure corresponding to the source of motive power for actuating a piston which is directly connected to a plurality of plungers. This plurality of plungers is alternately pushed into and pulled out of corresponding plunger-cylinders for creating an integral drive and pump system prerequisite for gas well site pumping operations. Instead of venting to the atmosphere, well gas is returned to the flow line whereupon only clean air from the self-generated instrument air circuit is vented into the atmosphere.

Abstract: A pump for boosting pressure of liquid color for injection into plastic resin in molding or extrusion apparatus includes a housing having a first bore extending in a first direction and second and third bores extending through the housing and communicating with the first bore proximate a first end of the first bore with the first end of the first bore being blind. The pump further includes an inlet check valve connectable to the second bore for permitting liquid flow through the second bore into the first bore. Further included is an outlet check valve connective to the third bore for permitting liquid flow out of the first bore through the third bore. A member is reciprocally axially movable within the first bore. A solenoid applies air pulses to the end of the first member facing oppositely from the blind end of the first bore.

Abstract: A fluid driven motor system including a source of pressurized drive fluid and at least one cylinder having a piston therein for reciprocating motion. The cylinder receives the pressurized drive fluid from the source, and a compressor receives drive fluid exhausted from the at least one cylinder. The pressurized drive fluid circulates in a closed loop from the compressor to the cylinder.

Abstract: A pump apparatus comprises a piston, which is provided displaceably along a first chamber formed in a body under the action of a pilot pressure, an indirect medium composed of a non-compressive fluid and which is to be pressed by the piston, and a diaphragm that is flexibly bendable in cooperation with the indirect medium. When the fluid is discharged from a discharge port, a change in volume caused by the displacement of the piston in the axial direction is identical to the change in volume caused by the displacement of the diaphragm in the axial direction.

Abstract: A liquid chemical supply system that performs accurate pressure feedback control and controls the discharge flow rate of liquid chemical with high precision, even when the pressure setting value of the operation pressure differs due to changes in the type of liquid chemical, includes a pump having a pump chamber and an operation chamber separated by a diaphragm comprised of a flexible membrane. The intake and discharge of liquid chemical is performed in accordance with the change in pressure inside the operation chamber. An electro-pneumatic regulator supplies operation gas pressure to the operation chamber. A plurality of pressure sensors having different pressure detection ranges is provided for detecting the operation gas pressure. A controller selectively employs any of the detection results of the plurality of sensors in accordance with the pressure setting value of the operation air that is set for each use, and performs pressure feedback control.

Abstract: A device for supplying ink to a printing press, includes a piston pump and a hydraulic or pneumatic cylinder driving mechanism which drives the piston rod of the piston pump and the cylinder driving mechanism includes several cylinder chambers, which are separated from one another and each of which contains a driving piston, which can be acted upon with pressure.

Abstract: A mechanical pump having a unitary construction such that the fluid being pumped is prevented from leaking without requiring the use of discrete seal elements. The absence of discrete seal elements and integral coupling of various components of the pump substantially reduces the likelihood of failure of potential leak points. This allows the pump to operate continuously for a longer period and with greater reliability than previously utilized pumps. The pump can be utilized in a greater number of applications without requiring special design consideration for the fluid being pumped. The absence of discrete seal elements also reduces the cost and complexity of manufacturing the pump.

Abstract: A pneumatic oscillator for providing pumping force to a pump. The oscillator has a single valve for controlling both the rate of oscillation of the oscillator and the flow of air. The valve includes a shuttle member and a detent mechanism. The detent mechanism controls the air flow in the oscillator and to the pump to which the oscillator is attached and the detent mechanism for regulating oscillation of the shuttle member. The configuration of the shuttle member and the detent mechanism eliminates the need for an additional valve to regulate oscillation of the oscillator. A cycle controller corresponding with the detent mechanism is adapted to change the rate of oscillation of shuttle member such that the need for additional valves or controllers for regulating the rate of oscillation is obviated.

Abstract: A pinch mechanism, which can be used as part of a pump, includes a deformable tube (10) enclosed within a body (11) which has a first chamber (11a). The deformable tube (10) defines a flow passage. A second chamber (19) is coupled via passage (17) to the first chamber (11a). A piston (20) is located within the second chamber (19) and movable between first and second positions. Upon moving to the first position a pressure increase occurs in the first chamber (11a). Upon moving to the second position a negative pressure is created in the first chamber (11a). A vent means (25) is located at a point during movement of the piston (20) between the first and second positions which enables pressure equalisation within the second chamber (19) to occur.

Abstract: A pumping system. The pumping system has a cylinder pump, a first group of switching devices, and a second group of switching devices. The first group of switching devices enable the cylinder pump to pump the liquid by feeding the gas provided by the gas source into the cylinder pump through a first ventilator according to a first enabling signal, and the second group of switching devices enable the cylinder to output the liquid by feeding the gas provided by the gas source into the cylinder pump through a second ventilator according to a second enable signal.

Abstract: A restarting device of a pump including a center rod defining fluid delivering chambers and driving chambers 11b and 12b. The restarting device of the pump further includes: a change-over valve 2 for switching a direction for the center rod to move, and a restarting hydraulic circuit 3 which, when a supply of the driving fluid from the change-over valve 2 to the driving chambers 11b and 12b in both sides is stopped, detects the supply of the driving fluid into the driving chambers 11b and 12b in both sides having been stopped and then causes the driving fluid to flow into the change-over valve, thereby restarting the supply of the driving fluid into the driving chambers 11b and 12b.

Abstract: A system and method for compressing gas uses a hydraulic pump and a hydraulic accumulator to compress gases in gaseous form. The accumulator is divided into a hydraulic chamber and a pneumatic chamber. The pneumatic chamber of the accumulator can be pneumatically connected to a gas supply and a gas receptacle that needs filled. One-way directional flow valves are used to permit the flow of gas from the gas supply to the pneumatic chamber and from the pneumatic chamber to the gas receptacle, but to prevent the flow of gas in the opposite direction. A motor drives the hydraulic pump, which moves pressurized oil into the hydraulic chamber of the accumulator. The pressurized oil within the hydraulic chamber of the accumulator compresses the gas within the pneumatic chamber of the accumulator, forcing the into a tank or other receptacle that needs filled. The invention can be used to compress a variety of gases at different flow rates, volumes, and pressures.

Abstract: A valve arrangement including a valve housing (10) which includes an inlet port (11) and two outlet ports (12, 13) for fluid flowing through the housing. A valve element (15) is accommodated in a first valve space in the valve housing and movable between two end positions. The valve element includes two surfaces (16), each of which is adapted for co-action with a respective outlet port such as to close an associated outlet port in one and the other of the end positions of the valve element (15). A device (20 or 21 and 26, 47) for resetting the valve element between the positions. The valve element (15) is mounted on one end of a pivotal arm (18) and has the form of a valve plate or disc which includes valve-element surfaces (16) for alternate co-action with a respective outlet port (12, 13).

Abstract: A valve housing (10) includes an inlet port (11) and two outlet ports (12, 13) for fluid passing through the housing. A valve element (15) accommodated in the valve housing is moveable freely between two end positions and has two surfaces (16) each adapted to close a respective outlet port in one and the other of the two end positions of the valve element. The valve element further includes members (20, 22: 21, 22: 21, 26, 47; 26, 48; 26, 50; 26, 51-54) for resetting between the positions. A double-action pump includes two spaces or rooms that have valve-controlled inlets and outlets (39, 40; 29, 30) for drive fluid and pump-transported working fluid respectively. The spaces are divided into an operating chamber (28) and a working chamber (27) by partition walls (26, 36, 37) which are pistons or diaphragms (26) and reciprocatingly move between end positions.

Abstract: A pneumatic pump pumps liquids from natural gas wells. First and second pneumatic rams have first and second pistons housed in first and second cylinders with a lifting beam connecting the first and second pistons above the first and second cylinders and connectable to sucker rods for lifting liquids from a well. First and second gas connections are provided beneath the first and second pistons in the first and second cylinders. First valves are connected to the first and second gas connections to introduce compressed gas beneath the first and second pistons for raising the lifting beam during an upstroke of the sucker rods and a first control valve regulates the up-stroke rate of the lifting beam. Second valves are connected to the first and second gas connections to exhaust gas beneath the first and second pistons for lowering the lifting beam during a down-stroke of the sucker rods and a second control valve regulates the down-stroke rate of the lifting beam.

Abstract: A delivery blood storing member-equipped blood reservoir tank has a blood reservoir tank portion, and a delivery blood storing member that communicates with a blood outlet formed in the blood reservoir tank portion. The delivery blood storing member allows blood to flow out of an interior thereof when pressed from outside. The delivery blood storing member reserves amounts of blood in accordance with the height of liquid surface in the blood reservoir tank portion if the amount of blood in the blood reservoir tank portion becomes equal to or less than a predetermined value. The delivery blood storing member includes a body part that is formed from a hard material, and a flexible diaphragm whose peripheral end is fixed to the delivery blood storing member body part. The diaphragm produces substantially no self-restoring force against deformation.

Abstract: A blood reservoir includes a blood tank, a blood accumulator connected in fluid communication with an outlet of the tank for receiving blood from the tank, and a pumping device for driving the accumulator to displace blood out of the accumulator. The accumulator typically in the form of a flexible bag is adapted to store blood in an amount proportional to the volume of blood in the tank when the volume of blood in the tank is reduced below a predetermined value. The pumping device is operated for intermittent blood delivery and can regulate the amount of blood displaced out of the accumulator.

Abstract: A micro-pump is disclosed for pneumatically causing a bulging/retracting motion of a plurality of micro-diaphragms disposed in an array along a channel through which a fluid is being driven. The pump includes channel means (10) including a first port (11), a second port (12) and a flow-through space (13) providing a communication therebetween; a plurality of diaphragms (21a-21e) disposed in an array along the flow-through space (13); diaphragm support means (20) including a plurality of actuating gas spaces (22a-22e) which opposes the rear surfaces of the respective diaphragms; a plurality of reciprocatory motion means for individually imparting an oscillation of pneumatic pressure to the respective actuating gas spaces (22a-22e), and drive means for driving the reciprocatory motion means for driving motion with phase differences therebetween so that the upper dead center shifts in the direction of the array.

Abstract: A non-invasive technique and system is provided for measuring flow of liquid driven by a flexible diaphragm of a membrane pump (18). Flow, pressure and/or temperature of a gas, such as air, used to drive the pump (18) is continuously monitored. Instantaneous volume of liquid being pulled into or out of a chamber of the pump (18) can be calculated from measured values of the gas used to drive the pump (18). Sensors (10, 12 and/or 14) are used to measure values relating to the gas. The sensed parameters are concurrently monitored and continuously determine the amount of gas flowing to and from the diaphragm of the membrane pump (18) utilized to move liquid within a liquid pathway. The measurements may then be used to calculate the instantaneous flow rate of the liquid.

Abstract: An hydraulic liquid system wherein a pump moves liquid from one location to another such as in supplying one or more loads in an underwater environment. The system includes two hydro-pneumatic chambers utilized such that one is filled by liquid from the pump while the other supplies the load, and as one hydro-pneumatic chamber empties, valves reconfigure the system such that the hydro-pneumatic chamber reverse roles. Each hydro-pneumatic chamber includes a liquid side and a gas side separated by a movable barrier with the gas sides of the hydro-pneumatic chambers being connected to one another thereby providing a large acoustic transmission drop across a liquid-gas boundary and subsequent gas-liquid boundary to interrupt the liquid noise path from the pump to the load.

Abstract: An integrated system and method are disclosed for filtering a fluid and for dispensing a desired volume of the fluid. The integrated system includes a feed pump sub-assembly for receiving fluid and for directing the fluid through a filter. A filtration sub-assembly is joined with the feed pump sub-assembly for receiving fluid from the feed pump sub-assembly and for housing the filter. A dispense pump sub-assembly is integrally joined with the filtration sub-assembly and defines a dispense chamber for receiving filtered fluid from the filtration sub-assembly. The dispense pump sub-assembly includes a dispensing means which is moveable from a fill position to a purge position for purging at least a portion of any gas bubbles from the dispense chamber. The gas bubbles are purged through a purge outlet disposed above a fluid inlet and a fluid outlet of the dispense chamber.

Abstract: A fluid pump is provided which comprises a valveless pump chamber, a tube for conveying fluid, a conduit connecting the pump chamber and tube in fluid pressure communication, and at least one valve connected to the tube and adapted to permit a flow of fluid therethrough substantially in a single direction. Preferably at least the tube is removable and replaceable from the pump chamber. Preferably also, the tube is substantially rigid and includes a second valve at an opposite side of the conduit from the first valve.

Abstract: A pump of extremely simple manufacture, requiring no maintenance, is made up of a tubular body (1) closed at each end by end pieces (10a and 10b), orifices (15a and 15b) of which are respectively connected to a pneumatic control circuit (4) and to the circuit of liquid in circulation (3). A piston (2) circulates freely within the tubular body, driven by an overpressure or an underpressure appearing in the upper chamber (17a) and controlled by the pneumatic control circuit. The displacement of the piston brings about the filling and emptying of the lower chamber (17b), thus permitting the pumping of a liquid. This type of pump, of universal use, needs only a connection to a compressor (40) and to a vacuum pump (41) for its running, and these two elements may be common to a great number of such pumps.

Abstract: A manual back-up emergency drive device for air driven artificial hearts, particularly for the "Jarvik-7" heart, is adapted to be instantly connected to the air drive lines for the heart in the event of power and air pressure failures and manually actuated to sustain the life of the heart recipient during the power failure. The device includes a bellows type manually actuated pump with a pressure stroke and a suction stroke, and an air delivery tube emerging from the pump coupled to a pair of air tubes having quick disconnect coupling units on the ends thereof for mating with coupling units on the ends of the air drive tubes to the heart. The device also includes a metering valve in the tube serving the right ventricle of the heart, an instrument reading the metered and pumped air pressures pulsing through the system and a make-up air intake in the pump.

Abstract: A redundant, pneumatic driver for a blood pump in which a pair of pistons are contained in a common cylinder and their stroke rates and lengths are selectively controlled by a controller which non-invasively senses the circulatory system requirements of the patient in which the blood pump is implanted. The controller varies the stroke rates and lengths to meet such requirements and further is able to selectively switch driving functions from one piston to the other to provide a redundant driving capability.

Abstract: An improved dynamic aortic patch is constructed with an elongate semi-rigid shell member having a concave inner surface and a flexible membrane integrally bonded to the outer surface of the shell to define an inflatable and deflatable chamber between the concave inner surface and the membrane. The pumping capacity of the patch is determined by the concavity of the inner surface of the shell member, thus enabling the construction of a patch which may be implanted in the thoracic cavity (small concavity) or in the abdomen (large concavity). A fabric layer bonded to the membrane over the area overlying the outer surface of the shell has a peripheral suture flange projecting freely clear of the membrane, and a temporary shield adapted to overlie the fabric layer may be employed to assure that sutures placed to attach the patch within an opening in the aorta are not inadvertently passed through the membrane.

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: A portable pumping system for administering fluids intravenously to a patient. The system has a tube connected between the fluid source and the patient with one-way valves at each end of the tube to limit the flow to one direction. A middle portion of the tube is positioned within a first chamber that is connected by a hose to a second chamber. The second chamber has a flexible member that is reciprocally moved by an arrangement that includes a housing and a source of compressed gas. The housing has a valved inlet and outlet and the flexible member forms a portion of the boundary of the housing. The valve for the outlet of the housing is attached to the flexible member which is a metallic disc inherently biased in a concave shape in relation to the housing. In operation, the flexible member inverts to a convex shape as pressure increases within the housing emitting a click.

Abstract: A cassette and controller for accurately controlling fluid flow through an administration set while maintaining a closed fluid system. Inlet and outlet conduits are defined in a body of the cassette and inlet and outlet valves control fluid flow through the respective conduits. A rigid internal cavity of predetermined volume is also defined in the cassette body with an impermeable and flexible diaphragm spanning the cavity. A control conduit communicates with the internal cavity on an opposite side of the diaphragm from the fluid to alternately exert negative and positive pressure on the diaphragm. Negative pressure causes the diaphragm to conform to the shape of the internal cavity when the inlet valve is open to fill the cavity-shaped diaphragm with fluid from the inlet conduit. Positive pressure against the diaphragm expels fluid from the cavity through the outlet conduit when the outlet valve is opened.

Abstract: A pump for transferring precise amounts of fluid from a container to a patient. A pump apparatus has a defined volume pump chamber divided by a diaphragm into a pumping fluid portion and a pumped fluid portion. The pumped fluid portion receives and exhausts pumped fluid in response to a decrease or increase in pressure in the pumping fluid portion of the pump chamber. The diaphragm and the defined volume pumping chamber provide accurate per cycle pumping volumes. The pumping fluid pressure is varied by periodically electrically heating a ribbon filament in a pumping fluid chamber thereby increasing the temperature and therefore the pressure and/or volume of the pumping fluid. The pumped fluid enters the pumping chamber through a one-way valve as the pumped fluid portion volume expands and is exhausted through a second one-way valve as the volume of the pumped fluid portion contracts. Control circuitry is provided to allow variations in the pulse repetition rate and pulsewidth.

Abstract: An inflatable/deflatable device for use in a body-implantable heart-assist pump. The device includes an inflatable/deflatable central portion, and a noninflatable, generally planar marginal portion joined thereto. In a preferred construction, the device is formed by the marginal joinder of a pair of flexible fluid-impervious sheets, wherein the central portion has opposite sides, and the marginal portion includes stretches distributed along these sides. The two flexible sheets may have different flexibilities, permitting the device to be inflated preferentially in a desired direction, and different curvatures, permitting the device to conform to adjoining surfaces in the heart-assist pump.

Abstract: Apparatus is disclosed for mechanically assisting circulation of blood in a patient for periods of up to a week or two until the patient's heart strengthens sufficiently to take over the full workload. The circulatory assist device includes a valveless pump with a flexible bladder, a pneumatic driver for applying pressure pulses to the bladder, and a single flexible conduit for conveying blood between the patient and the pump. In use the pump and driver are mounted external to the patient's body and the flexible conduit is connected to the pump and in end-to-side relationship with a major blood vessel on that side of the heart, either right or left, which is in need of support.

Abstract: A blood pump for implant or paracorporeal use having a rigid case with inlet and outlet valves defining a pumping cavity; an integral thin walled flexible sac freely confined within a pumping cavity; and a flexible diaphragm within the cavity conforming to the shape of the adjacent side of the sac. The case includes a control ring projecting into the cavity between the diaphragm and sac. The diaphragm is moved between diastolic and systolic positions to pump blood through the valves. During pumping, the ring distributes flexing of the diaphragm over an increased area while also preventing the interior walls of the sac from contacting each other. The outlet port and the portion of the sac immediately surrounding the outlet port are less flexible than the remainder of the sac away from the port and the portion of the diaphragm overlying the outlet port is less flexible than the remainder of the diaphragm.

Abstract: A parallel aorta passageway is provided with its upper end being connected to the aorta in close proximity to the heart. The opposite ends of the parallel aorta are grafted to the aorta without interrupting the blood flow through the heart and circulatory system. The parallel aorta is received in an outer tube with a balloon being positioned between the inner and outer tubes. An air line extends from the lower end of the balloon through the ribs under the flesh and out of the body through a hole drilled in the iliac crest. The tube is connected to an external control unit synchronized with the heart to provide counter pulsations 180.degree. out of phase with the heart pulsations.

Abstract: A mechanically operable bellows for feeding anesthetic and/or life sustaining gases to a patient during a surgical procedure.

Abstract: A pneumatic pump adapted primarily as a left ventricular heart assist device includes a flexible bladder with a rigid housing. A pneumatic driver applies rhythmical pulses between the bladder and the housing to repetitively collapse the bladder and establish a pumping action through the bladder, in conjunction with check valves in the inlet and outlet to the bladder. Between the driver and the pump there is provided a pneumatic pulse limiter which includes a flexible diaphragm isolating the driver from the pump. Pulses from the driver are transmitted to the pump only through the flexible diaphragm and the diaphragm is constrained to move only within established limits. Regardless of the magnitude of the pulse from the driver, the maximum pulse applied to the pump cannot exceed that corresponding to the maximum displacement of the diaphragm.Between successive pulses, the portion of the system between the driver and the flexible diaphragm is depressurized.

Abstract: Extracorporeal blood pumping apparatus for use, for example in cardiopulmonary bypass procedures, left ventricle assist, hemodialysis and the like. The pulsatile pump apparatus may comprise an elongated driver balloon and a similar blood pumping balloon positioned side by side in a rigid casing or housing having preferably a one-way air valve. The inlet and/or outlets of both balloons are off-set and sloping ballon end portions are provided, inter alia, to minimize folding and/or rubbing during use. The driver balloon is provided with a port for coupling to a pressure-vacuum source and the blood pumping balloon is provided with an inlet port and an outlet port and both balloons are of such a cross sectional size and construction as to provide non-occlusive action by the blood pumping balloon.