Abstract: Permanent magnets are buried on one side of an impeller, and a rotor having permanent magnets buried opposite thereto is provided to form a passive bearing. On the other side of the impeller, three electromagnet coils and three position sensors are circumferentially provided at equal distances to form an active bearing, the outputs of the three position sensors are operated to produce impeller displacements, which are fed back to drive the coils.

Abstract: An intravascular microaxial pump has an integrated configuration that enables both the drive unit as well as the pumping segment to be advanced through a patient's vasculature. The device includes elements that enhance pumping efficiency and performance while minimizing shear and cavitation. Cost reduction is achieved in the reusability of certain components while a manufacturing method reduces the labor involved in the pump's assembly.

Abstract: An artificial heart comprising a case with inlet and outlet openings for blood which can be implanted in human body instead of an incurable human heart and can provide the normal blood flows in both large (body) and small (lungs) blood circulations for a long period (years). It has a driving arrangement which has a driver armed with magnets and is placed outside the human body. The case is formed with cylindrical wall and two end plates and contains a movable grid consisting of twelve elongated wall elements which are disposed between said plates and which bear slidingly and sealingly on said plates, each wall element being articulately sealingly connected at its end points to at least one further wall element. The grid has nine axles; the central one is connected at least with one of the said plates, the remaining axles are free. The grid is armed with permanent magnets which cause the grid's rotation by their magnet coupling with the driving magnets of the driver.

Abstract: A magnetically-driven centrifugal blood pump includes a housing and an impeller mounted for rotation within. The impeller includes a generally disk-shaped base plate and a plurality of curvilinear vanes extending axially upward therefrom. The vanes project radially outward from the base plate approximately one-third of their curvilinear length. The housing includes a rear wall spaced from the impeller base plate across a constant gap, with a sloped transition wall surrounding the rear wall and joining it to a peripheral wall. A tangential outlet is provided in the peripheral wall. A front wall extends inward from the peripheral wall with a slight conicity to an axial inlet. The vanes each have a front edge which slopes away from the front wall in the radially outward direction to provide a widening gap therebetween. The vanes have inner ends which together define a vane-free inner region below and slightly larger than the inlet.

Abstract: An apparatus for pumping blood includes an elongated housing dimensioned to be at least partially positioned within the heart of a patient, a rotating member supported for rotational movement within the elongated housing and a drive mechanism for imparting rotational movement to the rotating member. The elongated housing includes an outer wall, a first inlet port for permitting blood to enter the elongated housing through a first end of the elongated housing and a second inlet port defined in the outer wall of the elongated housing for permitting blood to enter through the outer wall. The rotating member is rotatable to impart pumping energy to the blood entering through the first and second inlet ports to direct the blood through an outlet opening of the elongated housing. The rotating member preferably includes first and second blood pumping blade arrangements. The first blade arrangement is dimensioned to impart pump energy to the blood entering the elongated housing through the first inlet port.

Abstract: A centrifugal blood pump used for heart-lung machines or the like comprising an impeller provided with pump vanes and a magnet means such as permanent magnets, a casing having an inlet port and an outlet port and rotatably accommodating the impeller, and a magnet drive means disposed outside the casing, wherein the impeller is supported by at least three balls above the bottom plate of the casing, held at the center of the bottom plate and rotated around the center axis of the impeller by the magnet means and the magnet drive means. When the upper and lower ends of the rotation shaft of the impeller are supported by the casing, the upper end of the rotation shaft is supported by a bearing embeddedly disposed at the top section of the conical section of the casing, and the inlet port of the casing is disposed adjacent to and eccentric from the top section.

Abstract: In a pump housing (10), the blood pump comprises an impeller (13) with a flat plate (30) and blades (34) projecting therefrom. The impeller (13) is supported between balls (18,20) forming an axial sliding bearing. The front wall (35) and the back wall (14) of the pump housing extend substantially parallel to the plate (30) of the impeller (13). The height of the blades (34) linearly decreases with increasing radius so that the gap between the front wall (35) and the blades (34) increases outwards. Since the circumferential speed increases as well, the shearing rate remains constant. Between the plate (30) of the impeller and the back wall (14), a gap of constant width is provided, in which secondary flows are produced, thereby avoiding dead water zones.

Abstract: In a magnetically suspended type pump, an operating state of the pump can be obtained without using a pressure gauge and a flowmeter. In addition, in the case where the magnetically suspended type pump is applied to a blood pump, in order to reduce the number of connections in a flow path and to avoid thrombus formation, a correlation between current flowing in a motor and flow or a correlation between current flowing in the motor and pressure is obtained in advance, and the speed of rotation of motor is varied by a speed of rotation control circuit in response to an instruction from a CPU circuit, based on the obtained correlation between current and flow or between current and pressure, whereby flow or pressure is controlled.

Abstract: An axial-flow blood pump has a rotor suspended in ball-and-cup bearings which are blood-cooled but not actively blood-lubricated. The ball-and-cup structures are made of highly heat-conductive material and are in heat-transferring contact with heat-conductive stator blades that serve as heat sinks for the bearings. The ball-and-cup structures are radially much smaller than the stator blades. The ball-and-cup interface has so small a gap that the ball-to-cup structures present an essentially continuous surface to the blood flow.

Abstract: A rotary blood pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial and radial clearances of blades associated with the flow straightener, inducer portion, impeller portion and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with cross-linked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

Abstract: A pump for transferring fragile and aggressive liquids such as human blood and comprising a pumping chamber along with a pair of fluid inlet ports arranged in oppositely disposed relationship on the chamber, and one or more outlet ports arranged transversely and medially of the inlet ports. A rotor is positioned within the pumping chamber having a dual-conical configuration converging toward opposed polar end regions and with an axis of rotation extending between the polar regions. The rotor includes magnets which are arranged at radially spaced locations and with a magnetic drive positioned to deliver rotational driving energy to the rotor. The sole support for the rotor are the hydrodynamic forces acting upon the rotor during its operation, with the rotor body having a relative density of between 10% and 90% of the relative density of the fluid being pumped.

Abstract: A blood pump used for heart-lung machines comprising an impeller, a casing having a suction inlet and a delivery outlet and rotatably encasing the impeller, a magnetic driver disposed outside the casing, and a magnetic attraction force adjuster. The impeller has a rotationally symmetric shape, such as a conical shape, is equipped with vanes having a pumping function on the side surface thereof and is also equipped with magnets, such as permanent magnets. The magnetic driver for rotating the impeller in cooperation with the magnets comprises a magnet assembly magnetically connected to the magnets and a rotation driver for rotating the magnet assembly. The magnetic attraction force adjuster adjusts the magnetic attraction force generated between the magnets and the magnet assembly by adjusting the gap between the magnets and the magnet assembly or by adjusting the exciting current of electromagnets when electromagnets are used for the magnet assembly.

Abstract: Methods are provided for minimizing damage to blood in a blood pump wherein the blood pump comprises a plurality of pump components that may affect blood damage such as clearance between pump blades and housing, number of impeller blades, rounded or flat blade edges, variations in entrance angles of blades, impeller length, and the like. The process comprises selecting a plurality of pump components believed to affect blood damage such as those listed hereinbefore. Construction variations for each of the plurality of pump components are then selected. The pump components and variations are preferably listed in a matrix for easy visual comparison of test results. Blood is circulated through a pump configuration to test each variation of each pump component. After each test, total blood damage is determined for the blood pump. Preferably each pump component variation is tested at least three times to provide statistical results and check consistency of results.

Abstract: A centrifugal blood pump for heart-lung machines or the like. An impeller is provided with pump vanes and a magnet. The impeller is rotatably accommodated in a casing having an inlet and an outlet. A magnet drive means is disposed outside the casing. The impeller is supported by at least three balls above a bottom plate of the casing, held at the center of the bottom plate and rotated around the center axis of the impeller by the magnet means and the magnet drive means. When the upper and lower ends of the rotation shaft of the impeller are supported by the casing, the upper end of the rotation shaft is supported by a bearing embeddedly disposed at the top section of the conical section of the casing, and the inlet of the casing is disposed adjacent to and eccentric from the top section.

Abstract: An implantable electric blood pump has a motor stator defining a cylindrical blood conduit, and a pump rotor in which the motor rotor is embedded. The pump rotor is conical at each of its ends and terminates at each end in a ball-and-cup structure washed directly by the pumped blood stream. Grooves may be formed in the ball-and-cup structure to enhance the heat-removing washing action of the blood stream. The pump rotor is nested in the stator blades to shorten the pump and wash the outlet bearing with a partially circumferential blood flow. Titanium-titanium carbide facing alumina are the preferred materials for the rotary-stationary interface, and the gap of the rotary-stationary interface is kept so small that no significant amount of blood serum can penetrate between the mating surfaces of the interface.

Abstract: The present invention describes a new pump which can be used as a mechanical heart, as a body fluid, as a drug infusion pump, and in similar or related applications for the circulation of body fluids including but not limited to blood and oxygenated air. The pump includes a scroll type pump that has been modified for medical applications. The pump includes two scroll involute spiral elements that are maintained at an angular and radial offset so that both spiral elements interfit to make a plurality of line contacts between their spiral curved surfaces to thereby seal off and define at least one pair of fluid pockets. The relative orbital motion of the two spiral elements shifts the line contact along the spiral curved surfaces thus causing the fluid pockets to change in volume. Since the volume of the fluid pockets increases or decreases, depending on the direction of the orbital motion, the scroll type pump is capable of either compressing, expanding or pumping the body fluids.

Abstract: A blood pump used for heart-lung machines comprising an impeller, a casing having a suction inlet and a delivery outlet and rotatably encasing the impeller, a magnetic driver disposed outside the casing, and a magnetic attraction force adjuster. The impeller has a rotationally symmetric shape, such as a conical shape, is equipped with vanes having a pumping function on the side surface thereof and is also equipped with magnets, such as permanent magnets. The magnetic driver for rotating the impeller in cooperation with the magnets comprises a magnet assembly magnetically connected to the magnets and a rotation driver for rotating the magnet assembly. The magnetic attraction force adjuster adjusts the magnetic attraction force generated between the magnets and the magnet assembly by adjusting the gap between the magnets and the magnet assembly or by adjusting the exciting current of electromagnets when electromagnets are used for the magnet assembly.

Abstract: A rotary blood pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial and radial clearances of blades associated with the flow straightener, inducer portion, impeller portion and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with cross-linked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

Abstract: Highly-miniaturized rotary artificial hearts small enough to be implanted within the natural heart are provided. The entire radial load of a high-speed pump rotor and most of the axial load is carried by a radially stable arrangement of high-energy-product permanent magnets. The rotor is fully suspended and rotated magnetically, with the exception of a single thrust-bearing contact point which utilizes ultra-hard, wear-resistant material, preferentially diamond, located at the axis of rotation in a high-flow region of the pump. No sensors or electromagnets are required for the bearings. One preferred embodiment utilizes dual mirror-image axial or mixed flow impellers mounted on a single axis so as to pump from a central inflow port out both ends of the device.

Abstract: A dynamic blood pump includes a rotating core member and rotating ring portion effective to pre-spin blood before the blood enteres helical pumping channels of the pump. The blood is pumped and further rotated as it moves axially along the helical channels toward a centrifugal section of the pump. At the centrifugal pumping section circumferential velocity differentials are also controlled to diminish damage to the blood. Outwardly of the centrifugal pumping section, a forced-vortex pumping section communicates the pumped blood to an exit port.

Abstract: A centrifugal pump for shear sensitive fluids includes a pump housing defining an interior volume. An impeller comprising at least two vanes is rotatably mounted in the housing. The impeller vanes, which preferably are airfoil-shaped, are spaced from the interior housing of the pump whereby to leave a gap between the vanes and the pump housing so as to permit a portion of the fluid in the spacing to flow smoothly over the top contour of the impeller vanes.

Abstract: A fluid pump with a rotary impeller is disclosed which comprises an electromagnetically-driven, bearing-free, seal-free rotary impeller levitated by localized opposed, magnetic forces and by fluid forces, or by localized opposed magnetic forces only. Levitation by localized opposed magnetic forces alone or by a combination of magnetic and fluid forces of an impeller driven by electromagnetic forces eliminates the need for bearings and seals in the driving mechanism. This avoids the heat build-up and leakage associated with other pumping mechanisms, which can be of importance in pumping of physiological fluids such as blood. The levitating forces of the present invention are applied both axially and radially with respect to the impeller. The magnetic forces are provided by a combination of diamagnets or solenoids, opposed by permanent magnets, solenoids or electromagnets.

Abstract: A centrifugal pump for pumping biological fluids such as blood includes a housing which defines a pumping chamber. The pumping chamber encloses an impeller comprised of a spindle for rotation about a spindle axis and a plurality of blades positioned such that each inner blade end is positioned adjacent to the spindle. The plurality of inner blade ends forms a spin inducer which aids in decreasing hemolysis.

Abstract: A blood pump for circulating blood by a rotor rotating in a space of a casing which is formed substantially in a flat shape and has a suction port and a discharge port, comprises a conical projecting portion provided at the central portion of the rotor, and a blade body formed continuously to a vicinity of the outer periphery of the base portion of the projecting portion, in which upper side recessed passages and lower side passages are alternately and radially formed. Base portions of the upper side recessed passages and the lower side passages are interconnected to each other by communicating passages. With this blood pump, the passages for blood are formed at either of the upper and lower gaps between the rotor and the casing, so that blood is transferred to the outer peripheral portion, thus preventing the solidification of the blood due to the stagnation thereof.

Abstract: An apparatus is provided for separating cellular components of blood (red blood cells, white blood cells and platelets) from waste components (plasma, anticoagulant, toxins, and other relatively small molecules). The presently preferred embodiment is a two stage plasma separator apparatus. The first stage is comprised of a first chamber having inlet means for admitting blood requiring separation of cellular components from waste components, and outlet means for discharging blood processed in said first chamber. A first filter means is associated with the first chamber for separating cellular components from waste components of blood, the first filter means including first waste outlet means for discharging waste components of blood processed in the first chamber.

Abstract: A centrifugal blood pump, used for heart-lung machines or the like, comprises an impeller, a casing having a suction inlet and a delivery outlet and being equipped with a space for rotatably accommodating the impeller, and a magnetic drive means disposed outside the casing. The impeller is of a rotationally symmetric shape and has a rotary vane section and a cylindrical section equipped with a magnet means. The magnet drive means for generating a rotating magnetic field coaxially encloses the magnet means of the above-mentioned cylindrical section and rotates the impeller in cooperation with the magnet means. At least the end section of the impeller's rotation center on the rotary vane section side is supported preferably by a pivot bearing. The pivot and the bearing thereof are preferably made of ceramics.

Abstract: A centrifugal blood pump features a pump assembly including a cylindrical barrel insertable into a motor stator. The barrel contains a motor rotor which is directly coupled to the pump's impeller. The barrel can be oriented and locked in the motor stator in many different angular orientations. Hemolysis is prevented in spite of high speed operation by reducing the clearance between the impeller and the impeller chamber, rounding the edges of the impeller blades, and providing a deflector to prevent blood from being impelled more than once around the impeller chamber periphery. An efficient releasable locking mechanism is also disclosed, as is a preferred method of assembling the pump assembly with close tolerances.

Abstract: A sealless centrifugal blood pump is provided in which a rotatable impeller is supported in a pump housing by fluid bearings during operation. Rotational movement of the impeller is accomplished with an inverted motor for magnetically driving of the impeller and maintenance of the axial running position of the impeller relative to the housing. In an alternative embodiment, the axis of the rotor housing is radially displaced relative to the axes of drive element of the motor and the motor housing.

Abstract: A dynamic blood pump includes a rotating core member and rotating ring portion effective to pre-spin blood before the blood enteres helical pumping channels of the pump. The blood is pumped and further rotated as it moves axially along the helical channels toward a centrifugal section of the pump. At the centrifugal pumping section circumferential velocity differentials are also controlled to diminish damage to the blood. Outwardly of the centrifugal pumping section, a forced-vortex pumping section communicates the pumped blood to an exit port.

Abstract: A centrifugal pump for pumping biological fluids such as blood includes a housing which defines a pumping chamber. The pumping chamber encloses an impeller mounted on a spindle. The impeller carries coupling mechanisms which couple with an external source of rotation to rotate the impeller. The spindle allows the impeller to rotate freely, but both ends of the spindle are constrained in the axial and lateral directions. The housing includes an inlet and an outlet.

Abstract: A sealless centrifugal blood pump is provided in which a rotatable impeller is supported in a pump housing by fluid bearings during operation. Rotational movement of the impeller is accomplished with an inverted motor for magnetically driving of the impeller and maintenance of the axial running position of the impeller relative to the housing. In an alternative embodiment, the axis of the rotor housing is radially displaced relative to the axes of drive element of the motor and the motor housing.

Abstract: In a centrifugal pump for liquids, in particular for blood in extracorporeal circulation, comprising a containment body for an impeller having the shape of a disk and comprising magnets inside it and having, on both faces, blades adapted for making contact with the liquid; the containment body has at least one liquid inflow connection, which is connected to ducts for conveying the liquid proximate to the center of the impeller on both sides thereof, and at least one liquid outflow connection; the containment body is shaped so that it can be removably inserted in a seat defined in a fixed base within which there is at least one magnet arranged so as to face the seat and being connected to means adapted for rotating it so as to rotationally entrain the impeller.

Abstract: Disclosed is a blood pump apparatus for blood components, comprising a housing forming a substantially cylindrical liquid chamber, an inlet port formed at an upper central portion of the housing and communicating with a source of blood component and the chamber, an outlet port formed in a peripheral portion of the housing and communicating with the chamber, a rotator arranged in the chamber and having an upper cover and a lower shroud, a lower surface of the upper cover being inclined such that an angle .theta.

Abstract: An integrated heart-lung machine, which includes a blood pump having a casing of a cup-like shape interiorly defining a pump chamber at an intermediate portion thereof for pumping in and out blood from a blood inlet to a guide flange formed at opposite ends of the casing; a rotor having a rotary member securely fixed to the fore end thereof within the pump chamber and journalled in the guide flange; an artificial lung of a doughnut-like or cylindrical shape connected contiguously to a blood flow passage in the guide flange and concentrically with the rotor; a stator detachably fitted in an intermediate portion between the rotor and the artificial lung; and a pedestal base located at one side of the artificial lung and provided with a blood outlet in communication with the artificial lung.

Abstract: An axial flow blood pump for intracorporeal or extracorporeal use pumps blood axially through a cylindrical conduit disposed in the bloodstream of a patient. The pump further includes a pump stator mounted in the conduit and a motor stator located either externally or internally of the conduit which applies a magnetic flux in the conduit. A rotor located in the conduit carries permanent magnets which interact with the applied magnetic flux to rotate the rotor. The rotor also carries impeller blades which, during rotation, produces an axial flow of blood through the conduit. During rotor rotation, the rotor is radially suspended solely by one or more hydrodynamic bearings formed by blood flowing through the conduit, with the location of at least one hydrodynamic bearing defined by a radial gap between the inside surface of the conduit and the rotor.

Abstract: A fluid pump with rotary impeller is disclosed which comprises an electromagnetically-driven, bearing-free, seal-free rotary impeller levitated by localized opposed, repulsive, permanent magnetic forces and by fluid forces, or by localized opposed repulsive magnetic forces only. Levitation by localized opposed magnetic or magnetic and fluid forces of an impeller driven by electromagnetic forces eliminates the need for bearings and seals in the driving mechanism. This avoids the heat build-up and leakage associated with other pumping mechanisms, which can be of importance in pumping of physiological fluids such as blood. The levitating forces of the present invention are applied repulsively both axially and radially with respect to the impeller and are auto-adjusting, such that any attempted displacement of the impeller will automatically incur a corrective change in levitating forces.

Abstract: Centrifugal pumps (10) are disclosed having nonrotatable membranes (21) to rotate fluid in a pumping chamber having at least a first open passage inlet (71) and an open passage outlet (91). Specifically, the membrane (21) is deflected into a nonconcentric shape to the fluid rotation, with the nonconcentric shape being rotated to function as a centrifugal pump impeller by deformers (41, 42, 43) separated from the pumped fluid by the membrane (21). As the membrane (21) does not rotate, rotary shaft seals, bearings, or small gaps between moving, sliding, and/or rubbing pump surfaces and to which the pumped fluid is accessible are not required in the pumps (10). In preferred forms, the deformers (41, 42) can be located inside the membrane (21) and inside the pumping chamber or the deformer (43) can be located outside the membrane (21) and outside the pumping chamber.

Abstract: A medical pump comprises a casing having side walls, a peripheral wall, and a pump chamber defined thereby, an inlet port formed substantially in the central portion of one of the side walls of the casing, an outlet port formed in the peripheral wall of the casing so as to extend tangent thereto, a rocker substantially concentric with the inner peripheral surface of the casing and disposed in the chamber, and a rocker driving unit for rocking the rocker so as to vary the volume of the space between the rocker and the outlet port with the lapse of time, thereby producing a rotating flow in fluid in the casing.

Abstract: A two stage centrifugal and shear pump is characterized by low turbulence for pumping delicate liquids, as blood. Centrifugal first stage is a hollow shaft on which the shear pump discs are mounted. Offset slots in the shaft and disc hubs direct liquid out of the shaft to the discs.

Abstract: Perfusion pump driver apparatus for coupling motive power from a controller console to the rotator of perfusion pump. The coupler has a console adapter to connect the coupler apparatus to the pump control console. A pump receptacle is provided in the coupler to connect the pump to the driver. A power transfer mechanism consisting of a bushing and flexible shaft is provided in the coupler to adapt the control console characteristics to the pump characteristics.

Abstract: An extracorporeal blood pump which comprises a pump housing having a pump chamber defined therein, and a rotary vane assembly accommodated within the pump chamber and including a substantially conical rotary pedestal having a base surface and a conical surface, a plurality of vanes each having radially inner and outer ends, and a driven shaft connected at one end with the base surface of the pedestal. The vanes are mounted on the conical surface so as to extend radially outwardly from an axis of rotation of the pedestal with the radially inner ends of the respective vanes being spaced a predetermined equal distance from an apex of the conical surface while substantially depicting a circle coaxial with the axis of rotation of the pedestal. Each neighboring members of the vanes are equally spaced from each other in a direction circumferentially of the pedestal.

Abstract: A rotary blood pump includes an impeller in a pump chamber driven by a fluid motor. In a first preferred embodiment, the fluid motor includes a rotary member having a series of cupped fluid reactive surfaces that receive a tangential inlet pressurized fluid flow. The cupped surfaces direct the fluid to opposite sides of the rotary member. Passages extending through the rotary member convey fluid from one side of the rotary member to the other. In a second preferred arrangement, the fluid motor is defined by a positive displacement motor. In a third embodiment, the fluid motor is separated from the pump chamber by a wall. Both biocompatible and non-biocompatible fluids can be used to drive the fluid motor.

Abstract: A blood pump includes a housing an inlet and outlet communicating with a pump chamber. A rotor received in the pump chamber is rotated by a drive motor. A drive shaft extending between the motor and rotor passes through a seal which is purged from the non-blood side by fluid. The fluid side of the seal contains a pumping element to modulate the fluid pressure, thereby controlling the purge fluid flow.

Abstract: A turbo pump is disclosed, having a magnetically supported impeller. The turbo pump includes a casing (31) made of a non-magnetic material, an impeller (32) provided in the casing (31), a triaxial controlled magnetic bearing provided outside of the casing (31) for magnetically supporting the impeller (32), and a rotor (37) magnetically coupled to the impeller (32) for rotating the impeller. The triaxial controlled magnetic bearing includes a magnetic member (35) provided on one plane of the impeller and a plurality of electromagnets (39) provided in the casing in such a way as to be opposed to the magnetic member. Coupling between the impeller (32) and the rotor (37) is effected by a plurality of permanent magnets (33, 38) respectively provided thereon. In another aspect of the invention, a plurality of stator windings for generating the rotating magnetic field may be provided on the side of the stator in place of rotating means utilizing a magnetic coupling.

Abstract: A brushless DC motor has a rotor with impeller blades mounted thereon to pump blood through the central portion of the motor. Over a portion of its length, the rotor has a cylindrical surface that is spaced from a cooperating cylindrical surface on the motor stator. There is a gap between these cylindrical surfaces through which there is a leakage flow of blood. The relative motion between the cylindrical surfaces provides a hydrodynamic bearing that suspends the rotor in the stator.

Abstract: A blood pump includes a housing having an inlet and outlet communicating with a pump chamber. A rotor received in the pump chamber is rotated by a drive motor. A drive shaft extending between the motor and rotor is sealed by a fluid seal. The housing includes an opening defining a clearance with the drive shaft on the order of one or two thousandth (0.002) of an inch. A viscous, biocompatible fluid is utilized as the seal fluid.

Abstract: A fluid pump with rotary impeller is disclosed which comprises an electromagnetically driven rotary impeller levitated by localized opposed fluid forces. Levitation by localized opposed fluid forces of an impeller driven by electromagnetic forces eliminates the need for bearings and seals in the driving mechanism. This avoids the heat build-up and leakage associated with other pumping mechanisms, which can be of importance for pumping of physiological fluids such as blood. The levitating fluid forces of the present invention are auto-adjusting, such that any attempted displacement of the impeller will automatically incur a corrective change in levitating fluid forces. However, fluid force sensors and regulators could be incorporated into the present invention if desired. The invention should be of use in numerous medical and non-medical applications where the benefits of impeller levitation by localized fluid forces are apparent.

Abstract: A sealless centrifugal blood pump is provided in which a rotatable impeller is supported in a pump housing by fluid bearings during operation. Rotational movement of the impeller is accomplished with an inverted motor for magnetic driving of the impeller and maintenance of the axial running position of the impeller relative to the housing.

Abstract: A pump with a tubular housing having a predetermined inlet and outlet, a convoluted stationary member mounted in the tubular housing and a rod extending in a substantially spiral course received within the housing for rotation about the stationary member to move fluid from the inlet through the housing and from the outlet thereof.

Abstract: Perfusion pump driver apparatus for coupling motive power from a controller console to the rotator of perfusion pump. The coupler has a console adaptor to connect the coupler apparatus to the pump control console. A pump receptacle is provided in the coupler to connect the pump to the driver. Power transfer mechanisms are provided in the coupler to adapt the control console characteristics to the pump characteristics.