Abstract: A magnetotrictive peristaltic pump transfers a fluid from a supply chamber o a receiving chamber. The pump has a housing and a core section mounted within the housing. The core section is fabricated from a magnetostrictive material such as Terfenol-D, which can be made to expand directionally in the presence of a magnetic field. There is a fluid tight seal between the inner surface of the housing and the outer surface of the core section. Wrapped around the outer surface of the housing are a plurality of electrical coils. The positive terminal and the negative terminal of each coil are connected to a signal generator which generates direct current electrical signals to sequentially energize each coil. Energizing any one of the coils creates a magnetic field in the general area of the coil. In the presence of this magnetic field, the core section expands longitudinally resulting in lateral/radial shrinkage of the core section which creates a cavity in the general area of the magnetic field.

Abstract: A flexible tube pump, reference FIG. 2, having an elastic tube 1, compounded with a magnetically responsive material, stretched onto the surface of shaft 2 to provide a seal between the contacting surfaces. A magnetic field is applied concentrically to tube 1 which expands circumferentially away from shaft 2, but only locally to the field, the region outside the influence of the magnetic field however maintains the tube 1 to shaft 2 seal. The expansion of tube 1 forms volume 7. Repetitive movement of said magnetic field in direction of arrow 6 provides moving closed volumes giving pumping action, suitable as a dry, low pressure, pump, e.g. a vacuum pump.

Abstract: A subsurface well system contains well bore fluid and a pumping system which is lowered into the well bore on a conduit. The pumping system is supplied with electrical power through a conductor. The pumping system has a chamber, a discharge valve, and an intake valve for admitting the well bore fluid into the chamber. The chamber contains a reservoir that is filled with a reactive polymer gel that undergoes a significant change in volume in response to environmental changes. The gel expands when it is electrically stimulated, thereby forcibly expelling the fluid within the chamber. The gel contracts when it is not stimulated, thereby drawing fluid into the chamber. When electrical current is oscillated through the gel, the expansions and contractions repeat so that a pumping action of well bore fluid is achieved. The gel may also be formulated to react to an electromagnetic field. The gel of this embodiment contains metallic particles which increase in temperature when exposed to the magnetic field.

Abstract: An oscillating pump (10) includes a housing (11) which carries the components thereof. These components include an electromagnetic coil (24) surrounding an armature (23) carried by an impeller (12) which is positioned longitudinally between an inlet area (16) and an outlet area (17) of the pump (10). The armature (23) moves longitudinally upon activation of the coil (24). The impeller (12) includes a pair of bellows (19, 20) and carries a valve (13). The bellows (19, 20) define an inlet chamber (21) and a discharge chamber (22). Another valve (15) is carried by the housing adjacent to the discharge chamber (22). A cup (25) is formed at the inlet end of the impeller (12) and includes a lip (26) defining shoulders (28, 29). The housing (11) is also provided with areas defining shoulders (32, 33). A spring (34) is floatably positioned between the shoulders (28, 33) and another spring (35) is floatingly positioned between the shoulders (29, 32).

Abstract: A micropump in which a fluid is pumped by the interaction of longitudinal acoustic waves and the fluid in the microchannel. The micropump having an acoustical transducer responsive to a high-frequency input and directing a longitudinal acoustic wave into the channel which induces a pressure gradient. The fluid in the channel flowing in the direction of travel of the acoustic wave in the channel.

Abstract: A backup unit is provided with respect to a nozzle of a print head for printing by injecting ink, and sucks the ink from the nozzle, the backup unit including: a nozzle cap sealing the nozzle by making contiguous contact with the print head; a pump; and an ink path communicating the nozzle cap and the pump; wherein the pump includes: a bellows part having an internal space formed therein; a movable rod fixed to the bellows part and having an ink passage therein; a slide valve provided in the bellows part and slidable with respect to the rod, the slide valve closing and opening a hole provided at one end of the ink passage with respect to the internal space, depending on a position of the movable rod; an ink inlet provided at the other end of the ink passage and communicating with the ink path; and an ink outlet communicating with the internal space depending on a position of the slide valve, the slide valve having a stroke shorter than a stroke of the rod, a volume of the internal space within the bellows par

Abstract: A method for the enhanced accuracy in dispensing from a fluid roller dispensing pump, wherein a keyed one way insertable cassette with pump compressible tubing is utilized with the fluid dispensing pump. The cassette holds and maintains a compressible plastic tube adjacent a roller pump, whereby the rollers of the pump compress the tubing to draw and accurately dispense predetermined exact amounts of liquids into vials, hypodermics and the like for accurate medical and/or laboratory use, and wherein slightly improper placement still provides dispensing but with not always detectable inaccuracies. The cassette is provided with positive proper position indicator elements to ensure both proper orientation and complete locking engagement to ensure accurate pumping and dispensing. In a preferred embodiment the pump embodies current use sensors which determine if the cassette, which causes the pump to use more current, is present. A keyed one-way cassette fitting prevents improper placement.

Abstract: In a micromembrane pump with pump housing top and bottom parts and a membrane structure disposed between the housing top and bottom parts such that pump chambers, valves, flow channels and a cavity system are formed between the membrane structure and the housing parts, heating means are disposed on the membrane structure in the area of the pump housing for operating said pump and the cavity system is filled with a cement for joining the membrane and the housing parts.

Abstract: An aquarium pump comprises an air cylinder provided therein with an air admitting chamber, an air inputting chamber, an air outputting chamber, an air discharging chamber, an air winding chamber, and an air cap. As the air cap is actuated, the atmospheric air is drawn into the air cylinder in which the speed of the atmospheric air is reduced by the winding air ducts and the volute air ducts of the chambers. As the air cap is compressed, the air is forced out of the air cylinder via an air output tube without making noise.

Abstract: A pump system is described which is particularly suited for use as a left ventricular assist device for internal use in humans. The pump system generally includes a pump having a deformable sac formed in a seamless piece of flexible resilient material having (i) a pair of opposite substantially planar walls and of substantially circular shape joined by an annular wall of substantially semicircular cross-section and (ii) inlet and outlet means. The inlet means have an asymmetric tapered section positioned to direct the inlet flow toward the annular wall of the sac to produce a smooth circular flow within the sac and minimize thrombus formation. A pair of pusher plates are disposed on opposite sides of the sac. Each of the pusher plates are engageable with a respective one of the planar walls of the sac for displacing at least one of the planar walls toward the other to deform the sac. The pump system also includes removable inlet and outlet conduit means with valve means for controlling inlet and outlet flow.

Abstract: A diaphragm pump comprised of a shaft, means for rotating the shaft at a speed of less than 3,000 revolutions per minute, a first connecting rod connected to a first diaphragm and operatively connected to the shaft, a second connecting rod connected to a second diaphragm and operatively connected to the shaft, and means for converting rotary motion of the shaft into reciprocating linear motion of both the first connecting rod and the second connecting rod such that, as the first connecting rod is moved in a first direction at a first rate of travel, the second connecting rod is simultaneously moved in a second linear direction at a second rate of travel, which is equal to said first rate of travel, and wherein the second linear direction is the opposite of the first linear direction.

Abstract: A pump and a method for pumping liquid or fluid through a pair of resilient tubes includes a pushing mechanism which partially compresses the tubes in a balanced, alternating, rocking manner. The resilient tubes are held in a parallel relationship. The pushing mechanism alternately compresses the tubes. As one of the two parallel tubes is compressed, fluid is pumped out of the tube and at the same time fluid is drawn into the second tube as the latter tube resumes its original shape. The resilience of both tubes also is used to assist the pumping action in a balanced fashion, thereby providing a pump that has low power consumption and is lightweight.

Abstract: A pump system is described which is particularly suited for use as a left ventricular assist device for internal use in humans. The pump system generally includes a pump having a deformable sac formed in a seamless piece of flexible resilient material having (i) a pair of opposite substantially planar walls and of substantially circular shape joined by an annular wall of substantially semicircular cross-section and (ii) inlet and outlet means. The inlet means have an asymmetric tapered section positioned to direct the inlet flow toward the annular wall of the sac to produce a smooth circular flow within the sac and minimize thrombus formation. A pair of pusher plates are disposed on opposite sides of the sac. Each of the pusher plates are engageable with a respective one of the planar walls of the sac for displacing at least one of the planar walls toward the other to deform the sac. The pump system also includes removable inlet and outlet conduit means with valve means for controlling inlet and outlet flow.

Abstract: A magnetically-driven pump transferring fluid through a conduit is provided, having an electromagnet assembly selectively excited by a power source, and a non-ferromagnetic lever structure extending from the electromagnet assembly to the conduit, the lever structure having a ferro-magnetic portion, which may consist of a plate, at one end movable by the electromagnet assembly between a release position where the ferro-magnetic portion is angularly offset relative to the electromagnet assembly and a compression position where the ferro-magnetic portion is in substantially parallel contact with the electromagnet assembly, the ferro-magnetic portion enabling a striker portion at another end of the lever structure to compress the conduit at a predetermined frequency. The lever structure couples movement of the ferro-magnetic portion at one end with movement of a striker at the other end such that the ferro-magnetic portion moves within a lesser arcuate range and the striker moves within a greater arcuate range.

Abstract: An eddy current coupling with an electrically controllable field current is used to rotatably connect a drive motor to an oil well pumping mechanism where the eddy current drive speed is controlled to a reference speed using a speed feedback control system and operation can be limited in torque output by a torque feedback control system. In a first alternative embodiment, the eddy current coupling output speed is controlled by a stroke modulation unit using a first selected speed for the upward pumping stroke and a second selected speed for the downward pumping stroke. In a second alternative embodiment a controller is used to select torque or speed control for the upward or downward .pumping stroke.

Abstract: A fluid pump includes a housing constituted of a base integrally formed with an annular wall defining a fluid reservoir and carrying an electrical pumping device, and a casing enclosing the pumping device. One side of the casing is open and is attached to the base. The opposite side of the casing is closed but includes an opening snugly receiving the annular wall of the fluid reservoir for rigidifying the housing. The pumping device includes a bellows attached at one end to the annular wall and at the opposite end to a push rod coupled by a crank to an electrical motor.

Abstract: A pump and a method for pumping liquid or fluid through a pair resilient es includes a shuttle block which partially compresses the tubes in a balanced, alternating manner. The resilient tubes are held in a parallel relationship with a predetermined space defined therebetween. Within the predetermined space, a shuttle block is oscillated along the linear axis to partially compress the tubes in an alternating fashion. As one of the two parallel tubes is compressed, fluid is pumped out of the tube and at the same time fluid is drawn into the second tube as the latter tube resumes its original shape. The resilience of both tubes also is used to assist the pumping action in a balanced fashion, thereby providing a pump that has low power consumption and is lightweight.

Abstract: A pump mechanism using a drive motor having an external rotor. In one case, cams are mounted on the external surface of the rotor. Cam followers or peristaltic fingers engage the cams and move linearly in response to the rotational cam motion. The cam surfaces are rotated from adjacent cam surfaces to achieve a peristaltic effect through the peristaltic fingers sequentially pressing against the fluid tubing. In another case, the external surface of the rotor is threaded and elongated. A nut is mounted on the rotor and confined to travel in only a linear direction. A coupling arm is connected between the nut and a syringe plunger to force the plunger into the syringe barrel and thereby move the fluid.

Abstract: This invention describes a cartridge pump and dispensing assembly for applications where cartridges containing liquid reagents are interchanged often. The cartridge pump comprises a reagent reservoir which directly empties into a metering chamber. A valve is at each end of the metering chamber. The two valves are aligned in the same direction so as to allow unidirectional liquid flow. The metering chamber is made of a compressible material, such as flexible tubing, so that when an external compression is applied to the chamber, the liquid contained therein is forcibly expelled. As the compression is removed, the metering chamber resumes its former shape and draws liquid into the chamber from the reagent reservoir. A dispensing assembly with electromechanical actuators for compression of the metering chamber and a means for sensing the amount of liquid contained within the reagent reservoir are also shown.

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 vibrating column pump pumps liquid by making use of liquid vibration generated at the time when the vibrating pipe is vibrated in a longitudinal direction thereof. The vibrating column pump comprises a vibrating pipe for pumping liquid therethrough, flexible pipes for connecting both ends of the vibrating pipe with a stationary suction pipe and a stationary outlet pipe, vibrating means for vibrating the vibrating pipe in a longitudinal direction thereof, and retainer means for removably retaining the vibrating pipe in such a manner that the vibrating pipe is removably connected to the vibrating means. The liquid contacting unit including the vibrating pipe and the flexible pipes is separated from the vibrating means so that the liquid contacting unit is disposable and can be easily replaced with a new one.

Abstract: A medical pumping system has a supply tube (2), an outlet tube (6), a readily sterilizable, disposable cassette (3) connected to the tubes and engaged with the pump, and means (22,24) such as a motor-driven piston, for intermittently applying pressure to the cassette. The pumping system features a display and switch means (9, 10) on a front panel thereof, a pressure sensor (28), an optical fluid presence sensor (19), and a microprocessor (20) metering the volume of fluid pumped through said cassette (3), monitoring output signals from said sensors (18, 28), controlling the motor-driven piston in accordance with settings entered via said switch means (9,10), and directing output data to said display means (8). The microprocessor has a stored program for performing SET RATE, RUN, HOLD, VOLUME FED, and CLEAR VOLUME functions.

Abstract: A soap dispenser apparatus has a housing having a space formed in the housing for holding a soap container of a predetermined shape. The soap container has its own dispenser hose and nozzle formed therein and the dispenser hose fits through a squeeze pump and becomes part of the pump pumping the soap from the container. An electric motor has a gear box for gearing the motor down located in the housing and positioned to actuate a squeeze member to squeeze the dispenser hose against a pressure plate made of a self lubricating polymer. A sensor, such as an infrared sensor, senses a person's hand in line with the output of the soap container and dispenser nozzle and is coupled through a circuit to the electric motor to actuate the squeeze pump to pump the soap onto a person's hand positioned to receive the soap.

Abstract: A micropump comprising a pumping chamber, an inlet channel communicating with the pumping chamber by an inlet valve and an outlet channel communicating with the pumping chamber via an outlet valve, these elements being manufactured by etching a silicon wafer is then sealed to glass wafers, the micropump also comprising a piezoelectric wafer to vary the volume of the pumping chamber by bending a wall forming part of the wall of this pumping chamber. In accordance with the invention the pumping chamber has a stop which determines the amplitude of movement of the flexible wall. The variation in the volume of the chamber caused by the displacement of the flexible wall is precisely defined, thus making it possible to maintain the output of the micropump constant during normal operating conditions.

Abstract: A zero net external displacement implantable pump for the transfer of accumulated body fluids, such as transfer of ascites fluid from the peritoneum to the vasculative system. The pump includes a pair of bellows type displacement chambers which are alternately compressed and expanded by action of a pivoted rocker member. The fluid to be transferred is drawn into the chambers on the expansion strokes and expelled on the compression strokes. The rocker member may be operated manually or power driven. Single action and double action pumps are disclosed.

Abstract: A microprocessor controlled bellows-type pump system for the precise and accurate pumping and dispensing of fluids. The pump comprises a longitudinally contracting bellows which is supported from warping under fluid pressure by a support bushing in contact with the inside folds of the bellows. A stepper motor drives the bellows position via a lead screw. A system of four valves: a dispense valve, shut-off valve, vent valve, and suck-back valve, control fluid routing within a manifold. One or two pressure transducers allow the microprocessor to control valve positions and stepper motor turning for well behaved dispensing operations.

Abstract: A ferromagnetic-fluid pump includes a hollow body having a substantially rigid structure and an internal diaphragm dividing said body in two cavities. Each cavity has an inlet and an outlet opening provided with one-way valve. One edge of said diaphragm is hinged on the body structure while its opposite edge is spaced from the adjacent inner surface of said body. Said cavities are partially filled with a ferromagnetic fluid which seals said diaphragm in respect of the inner surface of said body. At least one electric winding is provided onto both sides of said diaphragm and onto the two inner surfaces of said body facing said diaphragm. Said windings are operative to generate a variable magnetic fluid so that said diaphragm oscillates.

Abstract: A readily sterilizable, disposable cassette (3) can be used in a medical pumping system having a supply tube (2), an outlet tube (6) and means (22,24), such as a motor-driven piston, for intermittently applying pressure to the cassette. The cassette features a hydraulically self-actuating inlet valve (44) communicating with the supply tube (2), a hydraulically self-actuating outlet check valve (42) communicating with, and preventing backflow from, the outlet tube (6), a hollow, resilient compressible member, such as a bellows (34), having an interior communicating with the inlet and outlet valves, and a support structure (30,36,38) securing together the tubes, valves and bellows in operating relation. Preferably, the inlet and outlet valves are a unitary element. An optical sensing system detects fluid exhaustion in the cassette. The cassette has an irregularly-shaped cap (38) which prevents incorrect insertion into a pump.

Abstract: Provided are a pair of pumps, each of which comprises a bellows having an intake inlet and a discharge outlet, a reciprocating drive means for contraction and expansion movements of the bellows, and a couple of electro-magnetic on-off valves disposed respectively in the intake inlet side and discharge outlet side of the bellows, so that, during the contracting motion of the bellows, the electro-magnetic on-off valve in the intake inlet side becomes closed while the electro-magnetic on-off valve in the discharge outlet side becomes open, and during the expanding motion of the bellows, the electro-magnetic on-off valve in the intake inlet side becomes open while the electro-magnetic on-off valve in the discharge outlet side becomes closed. The paired pumps perform the discharge motions alternately. The discharge outlets of the pumps at their ends are fluidly connected via a directional valve with a discharging gun.

Abstract: An improved artificial heart (10) for pumping blood. The artificial heart (10) comprises first and second pump units (12 and 14), each including a pump body (16) defining a collapsible bellows (18) and a fluid passageway (20) therethrough. Further, each pump body (16) has a first end portion (22) defining an outlet opening (30) and a second end portion (26) defining an inlet opening (32). Each of the first and second pump units (12 and 14) further comprises first and second valve units (24 and 28). The first valve unit (24) is secured to the first end portion (22) of the pump body (16) in fluid communication with the outlet opening (32), and includes a first one-way valve (38) for allowing blood to flow out of the pump body (16) and restricting the flow of blood into the pump body (16).

Abstract: A pulse-actuated hydraulic pump includes a hydraulic chamber with a bellows having a volume increased or decreased by the selective application a force in an axial direction thereof by a piezoelectric actuator. Control means control electrically-driven valves to selective discharge fluid from the bellows in precisely controllable volumes through a first pumping port or a second pumping port.

Abstract: A pump with a continuous inflow and a pulsating outflow comprises a first chamber and a second chamber with a passage between them and made at least partly from a flexible material. There is an inlet to the first chamber and an outlet from the second chamber. The passage between the chambers has a one-way valve permitting flow only in a direction from the first to the second chamber. A second one-way valve located at the outlet permits flow only in a direction out of the second chamber. The chambers are movably supported in a pump casing having a first and a second opening. The inlet is connected to and penetrates the first opening, and the outlet is connected to and penetrates the second opening. A drive arrangement reduces the volume of the second chamber to expel the pumped medium while simultaneously enabling the walls of the first chamber to increase the volume and permit the pumped medium to flow through the inlet into the first chamber.

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: An implantable, anti-reflux, fluid displacement peritoneovenous shunt system. The system includes a double chambered multi-micro-orifice ascites collection device, a magnetically driven pump, and an anti-reflux, anti-backdiffusion, non-thrombogenic catheter tip, all connected by flexible tubing. The shunt is used to transfer fluid from the peritoneum to the cardivascular system to prevent accumulation of fluid within the peritoneal cavity. The magnetically operated pump may be of either the reciprocating diaphragm or piston type or it may be a rotary driven bellows displacement pump.

Abstract: A surgically implantable prosthesis system including at least one flexible inflatable member and an imperforate housing. A flexible combination reservoir and pump located within the housing for storing liquid when the inflatable member is deflated and for pumping liquid into the inflatable member and a flexible tube connecting the combination reservoir and pump and the inflatable member for the passage of a liquid between the combination reservoir and pump and the inflatable member. A rechargeable battery operates a reversible electric motor located within the housing operatively connected to the combination reservoir and pump to collapse the combination reservoir and pump to force liquid out of the combination reservoir and pump through the tube into the inflatable member and to expand the combination reservoir and pump to receive liquid from the inflatable member and a battery located within the housing to operate the motor.

Abstract: In an infusion pump or especially a peristaltic infusion pump of the type in which a drug liquid is forced to flow through an infusion tube by peristalsis, the pump mechanism can be readily pulled out of the main body. More specifically, the pump mechanism can be detachably fitted into and held at a predetermined position in a pump mechanism housing recess defined in an infusion pump casing and the pumping mechanism is then drivingly coupled through a suitable power transmission mechanism with a driving means disposed within the casing. And the pump mechanism is separated from the interior of the casing by means of the pump mechanism housing recess.

Abstract: A pump includes a pair of circular metal bellows rigidly secured to the pump housing at the perimeter of their accordion-like ring structures and interconnected at their centers so as to be capable of flexing in phase. An electrical coil is attached to the interconnected bellows and is axially movable with the bellows. The coil is surrounded by a permanent magnet structure secured to the pump housing. Each bellows communicates with an associated fluid chamber which has a valve structure for the inlet and outlet of fluid. The coil is electrically connected to an alternating current power supply, the connection being made through the electrically conductive bellows. The bellows flex in phase in the presence of the alternating current to the coil and thus alternately pull fluid in and force fluid out of the respective fluid chambers. Since the fluid chambers are connected to a common fluid output and since the bellows axially flex in phase, there are two pressure pulses per pump cycle.

Abstract: Inside a flexible shell (10), a deformable pocket (20) is connected to blood circulation via an inlet valve (30) and an outlet valve (40). The pocket is compressed by a floating assembly comprising a drum (50), and a bracket (60) rotatable about the axis thereof. One of the edges (21) of the pocket (20) is fixed to the drum (50); the opposite edge (22) is connected to the bracket (60) by a traction link (70), for example an inextensible sheet. Relative rotation between the drum and the bracket over a fraction of a turn enables the pocket (20) to be wrapped around the drum (50) and the assembly returns to its starting position under the effect of venous pressure. The disposition of the various components provides a self-adapting lever which limits mechanical losses to rolling friction between the drum and the pocket.

Abstract: An air bubble detecting and discriminating circuit arrangement especially suitable for use in a peristaltic infusion pump assembly is disclosed herein. This arrangement not only detects air bubbles in the fluid flowing through the tubing forming part of the assembly, but distinguishes between those bubbles which are sufficiently large to create a problem and smaller, micro bubbles which need not be detected. The arrangement also automatically compensates for changes in the flow rate of the fluid through the pump assemblies tubing without requiring any modifications at the time the flow rate is changed.

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: A fluid pump device for use in conjunction with a tubular pumping chamber which is composed of an elastic material and which has a pair of spaced-apart unidirectional valves through which fluid can be passed with cyclic compression and expansion of the chamber. The pump device is intended for medical or veterinary applications and it comprises spaced-apart clamp elements between which the pumping chamber can be removably located, an electrically actuated solenoid device for effecting cyclic relative movement of the clamp elements whereby cyclic changes in the contained volume of the pumping chamber are induced when the chamber is located between the clamp elements, and electrical circuitry associated with the solenoid for energizing the solenoid at a selectable repetition rate.

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: To decrease hemolysis and reduce the cost of single use disposable tubing used during surgery, valve elements pivotally suspended in the bypass pump compression chamber respond to gravity and variations in fluid pressure within the shunt and act entirely on the exterior of the shunt to cyclically control blood flow therethrough. Interior valves for the shunt tubing are entirely eliminated.

Abstract: A mechanical heart for implantation into the human body is run at a higher frequency which is a harmonic multiple of a normal heart beat frequency, and the pump chamber volume is reduced, proportionately to the increased pumping frequency. The circuit for controlling the frequency includes a phase locked loop for implementing a predictive algorithm which adjusts the frequency dynamically based on heart muscle nerve ending signals to synchronize the circuit output to the biologically determined heart beat. The reduced displacement permits use of a smaller compliance chamber. A novel interconnection between the motor chambers of a plurality of such pumps eliminates the need for venting and compliance chambers in a totally implanted heart system.

Abstract: A peristaltic pump, more specially for enteral nutrition or feeding has an electric motor and a wheel, on which rollers are supported, with axis crossing the axis of the electric motor so that the main dimension of the wheel in its radial direction and the main dimension of the electric motor in its axial direction are parallel to each other or in line with each other so that a specially flat mechanical design of the pump is produced. The shaft of the electric motor has a pinion for meshing with teeth in a radial plane on the outer edge of the wheel and driving it, this producing a high step-down ratio of 1:500 or even more. The wheel with the rollers may have a generally large diameter so that it may be run at a low speed quietly. With such a diameter of the support wheel and when the pump has a flat rectangular housing, empty corners will be present in the housing on the two sides of the electric motor, into which batteries or the like may be placed.

Abstract: A miniature apparatus for compressing gases is disclosed in which an elastomer disposed between two opposing electrostrictive or piezoelectric ceramic blocks, or between a single electrostrictive or piezoelectric ceramic block and a rigid surface, is caused to extrude into or recede from a channel defined adjacent to the elastomer in response to application or removal of an electric field from the blocks. Individual cells of blocks and elastomer are connected to effect a gas compression by peristaltic activation of the individual cells. The apparatus is self-valving in that the first and last cells operate as inlet and outlet valves, respectively. Preferred electrostrictive and piezoelectric ceramic materials are disclosed, and an alternative, non-peristaltic embodiment of the apparatus is described.

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 valve having no friction producing components includes a flexible and resilient tube for carrying a fluid, an electrically energizable coil for producing an electromagnetic force when energized, a magnetically attractable element, and an elongate leaf spring attached near one end to the coil and looped outwardly, upwardly and back toward the coil, with the magnetically attractable element attached to the leaf spring near the other end. The leaf spring normally holds the magnetically attractable element out of contact with the coil, but when the coil is energized, the element is attracted towards the coil. The one end of the leaf spring attached to the coil is also formed to extend upwardly and over the magnetically attractable element to act as an anvil, and the other end of the leaf spring attached to the element extends upwardly towards the anvil to form a pinching tab.

Abstract: A pump is described in which a flexible enclosure defines a pump chamber whose contents are expelled by movement of a pusher plate engaged with the enclosure. The pusher plate is moved by an elongate beam spring interconnecting the pusher plate with a solenoid drive mechanism. Solenoid actuation causes flexing of the beam spring from a relatively less stressed to a relatively more stressed position, the increased stress in the spring being relieved by pusher element movement. A preferred embodiment of the invention includes a symmetrical arrangement of opposed pusher elements and associated beam springs.

Abstract: A method and apparatus of pumping a fluid by means of a piezoelectric pump is provided. All moving parts, including the valves and impeller, are piezoelectrically motivated. The preferred embodiment includes a piezoelectric ceramic tube having conductive bands adhered to the outer surface. The conductive bands and an inner surface electrode define tube regions which serve as valve and reservoir pump regions.