Abstract:
A blood pumping system to support living organisms based on a spherical multi vane and multi chamber pump with an oscillating motion that delivers pulsatile flow. The blood pumping system includes a number of design elements that address the particular needs and compatibility issues (both biological and hemological) of a blood pumping system.

Description:
TECHNICAL FIELD  
       [0001]     The invention relates generally to artificial heart pumping systems that can be used either externally (non-implantable) or internally (implantable) with respect to the human body for maintaining life-sustaining circulation.  
       BACKGROUND  
       [0002]     The failure of the heart to provide adequate circulation of blood is a serious life-threatening problem. Heart transplants have treated the most serious cases of heart failures. A heart transplants though is a drastic procedure with high risk and the supply of donors is limited when compared to the total need. Considerable research and development has been done therefore into developing artificial hearts that can replace the human heart. Currently most artificial heart blood pumping systems are used more as temporary heart assistants pending the location of a heart donor.  
         [0003]     A variety of functional designs for artificial hearts are in the patent prior art and a number of functional designs now exist and are in use at various heart centers around the world. The AbioCor™ implantable replaceable heart, provided by ABIOMED, Inc. is a self-contained implantable replacement heart. This pump weighs about two pounds and consists of artificial ventricles that contain corresponding valves and a motor driven hydraulic pumping system. The hydraulic pumping system uses pressure to move blood from the artificial right ventricle to the lungs or from the artificial left ventricle to the rest of the body. To create this pressure the pump motor rotates at 4000 to 8000 rpm. Another system, the ABIOMED BVS-5000 is an air driven dual chamber blood pump placed outside the body used primarily for temporary left, right, or biventricular support of patients with heart failure. The pump houses two polyurethane chambers, an atrial chamber that fills with blood through gravitational force and a ventricle chamber that pumps blood by air-driven power. Two trileaflet valves separate the chambers.  
         [0004]     The Thoratec HeartMate® implantable pneumatic left ventricular assist system is based on an air-driven titanium alloy pump that weighs about 570 grams and consists of a blood chamber, an air chamber, a drive line and inflow and outflow conduits. Each conduit is a titanium cage that contains a valve within a Dacron fabric graft. The pump is powered and controlled by an external portable console. The Thoratec HeartMate II® is an implantable left ventricular assist system based on a continuous axial flow in-line pump. There are other artificial blood pumping systems under development and in use.  
         [0005]     The existing solutions have provided utility and prolonged lives. There are still many issues to be addressed however. Many of the prior solutions provide continuous flow whereas a problem free pulsatile flow that provides a more physiologic flow of blood is needed. Pulsatile flow is sometimes provided by flexible-volume chambers (bladders, tubing, bellows) but these are susceptible to wear and prone to thrombosis. Thrombosis as related to medical devices is the formation of blood clots on, or inside of, a medical device, and can lead to serious consequences. Flexible-volume chambers that do not completely or nearly completely expel their contained fluid during each stroke can also be prone to thrombosis. Another issue is simply size. Pumping systems with multiple chambers and the accompanying drive mechanism are typically too large to fit in smaller adults or children. Partially related to size is energy efficiency, with these systems requiring too much energy to operate. In addition to size though, many designs are inherently energy inefficient because of mechanisms that require reversing motion (pistons, bladders) that expends additional energy. Another issue evident from the above discussion of some of the existing systems is the use of valves. Valves not only add to size and complexity (and therefore reliability) but also are prone to calcification, wearing out and to thrombosis. Some of the prior art systems and devices also have problems with hemolysis (breakdown of red blood cells) due to either mechanical forces or shear forces in the motion of the fluid. Finally there is a definite need for easier flow modification of blood pumping systems. Many of the existing systems require separate drive force or shunting to accomplish this. Additionally, none of the prior art devices are known to provide two streams with simultaneous discharge pulsation peaks or simultaneous intake strokes, which simultaneity is physiologically desirable.  
         [0006]     The above needs can be addressed by applying modifications of new pumping technology to the special problems of blood pumping systems.  
         [0007]     Spherical rotary pumping systems have been developed that consist of a spherical housing within which one or more vanes rotate. This is in contrast to those devices that utilize a reciprocating, linearly moving piston. In the case of the spherical rotary pumps the vanes are rotated by a shaft to cause the fluid to flow through the device.  
         [0008]     U.S. Pat. No. 5,199,864 to Stecklein discloses a rotary fluid pump that employs vanes rotating within a spherical housing and includes an interior carrier ring that guides a particular motion of the vanes so that they open and close to draw in and either pump or compress fluids, thereby creating a type of pulsatile flow. This patent also describes an embodiment (the “second embodiment”) that uses an exterior carrier ring to guide the reciprocal motion of the vanes. These devices are highly efficient, and are capable of displacing large quantities of fluid relative to their size, so that the use of a small pump is possible. The flow of fluid is typically controlled by the rate at which the rotary vanes are rotated. By increasing the speed, more fluid is pumped through the device, while decreasing the speed decreases the amount of fluid pumped.  
         [0009]     U.S. Pat. No. 6,241,493 to Turner discloses a particularly useful improvement on this type of spherical fluid machine that is configured to enable adjustments in both fluid capacity and fluid direction without changing the speed or direction of rotation of the vanes in the device by adjusting the orientation of an interior carrier ring. That patent is incorporated by reference into this application.  
         [0010]     Fluid machines such as that described in U.S. Pat. No. 6,241,493 and U.S. Pat. No. 5,199,864 are also already ported, meaning that the manner in which the chambers communicate with the inlet and discharge ports negates the need for valves. They can be especially long running from a maintenance perspective because there is no direct physical contact between either the vanes and the central sphere around which they rotate nor physical contact between the vanes and the exterior housing of the machine. Low leakage between chambers is achieved by maintaining small clearances that minimize slippage or fluid loss across the clearances.  
         [0011]     Further improvements to these types of spherical rotary pumps are disclosed in U.S. patent application Ser. No. 10/784,709 by the inventor of the instant invention and that application is incorporated herein by reference in its entirety. These improvements included adding stability to the design, adding internal cooling, incorporating the ability to pump multiple fluids, and adding critical seals. Some of these improvements were aimed at the dual use of this type of a pump as a fluid pump as well as a compressor and/or motor in industrial applications. It is important to note that none of the prior art references on these spherical rotary pumps recognized their potential value as an artificial heart or as a ventricular assist device nor were the particular issues inherent in adapting this solution for those applications recognized or dealt with in these references. For example, issues related to biocompatibility, hemocompatibility, hemolysis and thrombosis were not addressed. The crux of the instant invention is the recognition of the need and the adaptation of these devices for this application.  
       SUMMARY  
       [0012]     These and other needs are addressed by the present invention, which simultaneously provides a method and apparatus for providing a reliable, adjustable pulsatile blood flow with a very small, efficient spherical blood pump that can be used as an implantable or external device and that can be easily configured to pump either one or two fluids. The instant invention also includes a number of other embodiments that address the particular needs of blood pumping systems that will be connected to a living organism, including improved biocompatibility, improved hemocompatibility and significantly reduced hemolysis and thrombosis.  
         [0013]     For purposes of the description here the solutions will be described with respect to a fluid machine similar to the one described in U.S. Pat. No. 6,241,493. Accordingly that prior art fluid machine will be described first in some detail. It should be recognized however that the instant invention could be potentially applied in any spherical pump such as those described in U.S. Pat. No. 5,199,864 or in U.S. Pat. No. 5,147,193.  
         [0014]     One aspect of the pulsatile blood pumping system of this invention then includes at least a housing having a wall defining a generally spherical interior, the housing having at least one intake port opening in communication with the interior of the housing and at least one discharge port opening in communication with the interior of the housing, and further including at least a first shaft mounted for rotation relative to the housing about a primary axis, where at least a portion of the first shaft extends through the housing wall and where at least one primary vane is disposed within the interior of the housing that rotates about the primary axis of the first shaft; at least one secondary vane disposed within the interior of the housing and mounted to the primary vane on a first pivotal axis, the secondary vane pivotally oscillating between alternating relatively open and closed positions with respect to the primary vane and defining at least a chamber within the housing interior having a volume which varies as the primary vane is rotated about the primary axis; and where the at least one intake port opening and at least one discharge port opening are connected to circulate at least one blood fluid through a living organism.  
         [0015]     The pulsatile blood pumping system of this invention also includes at least a housing having a wall defining a generally spherical interior, the housing having at least one port opening in communication with the interior of the housing; a first shaft mounted for rotation relative to the housing about a primary axis, wherein at least a portion of the first shaft extends through the housing wall; at least one primary vane disposed within the interior of the housing that rotates about the primary axis of the first shaft; at least one secondary vane disposed within the interior of the housing and mounted to the primary vane on a first pivotal axis, the secondary vane pivotally oscillating between alternating relatively open and closed positions with respect to the primary vane and defining at least a chamber within the housing interior having a volume which varies as the primary vane is rotated about the primary axis; the secondary vane being pivotally coupled to a carrier ring, so that the secondary vane is pivotal about a second pivotal axis perpendicular to the axis of rotation of the carrier ring causing the secondary vane to reciprocate between relatively open and closed positions as the secondary vane is rotated about the primary axis by the first shaft; the axis of rotation of the carrier ring being oriented at an oblique angle in relation to the primary axis of the first shaft; a second shaft that extends into the interior of the housing opposite the first shaft, the second shaft having a spherical portion about which the primary vane rotates and wherein the carrier ring is rotatably carried on the spherical portion of the second shaft; and wherein the at least one intake port opening and at least one discharge port opening are connected to circulate at least one blood fluid through a living organism.  
         [0016]     The pulsatile blood pumping system of this invention also includes a housing having a wall defining a generally spherical interior, the housing having at least one intake port opening in communication with the interior of the housing and at least one discharge port opening in communication with the interior of the housing, and including at least a first shaft mounted for rotation relative to the housing about a primary axis, wherein at least a portion of the first shaft extends through the housing wall; at least one primary vane disposed within the interior of the housing that rotates about the primary axis of the first shaft; at least one secondary vane disposed within the interior of the housing and mounted to the primary vane on a first pivotal axis, the secondary vane pivotally oscillating between alternating relatively open and closed positions with respect to the primary vane and defining at least a chamber within the housing interior having a volume which varies as the primary vane is rotated about the primary axis; wherein the at least one intake port opening and the at least one discharge port opening are operated simultaneously to both input and discharge blood fluids.  
         [0017]     Another aspect of the instant invention is a method for simultaneously inputting and discharging at least one blood fluid through a blood pumping system in a pulsatile manner comprising the steps of providing a housing having a wall defining a generally spherical interior, the housing having at least one intake port opening in communication with the interior of the housing and at least one discharge port opening in communication with the interior of the housing through which at least one blood fluid flows connecting at least one intake port opening and at least one discharge port opening to enable the circulation of at least one blood fluid through the living organism, rotating a first shaft mounted for rotation relative to the housing about a primary axis, wherein at least a portion of the first shaft extends through the housing wall; rotating at least one primary vane disposed within the interior of the housing that rotates about the primary axis; providing at least one secondary vane disposed within the interior of the housing and mounted to the primary vane on a first pivotal axis; and rotating the primary vane about the primary axis with the secondary vane pivotally oscillating between alternating relatively open and closed positions with respect to the primary vane; the housing, the primary vane, and the secondary vane defining at least one fluid chamber for containing fluid within the housing interior having a volume that varies as the primary vane is rotated about the primary axis.  
         [0018]     Another aspect of the instant invention is a method for circulating at least one blood fluid through a living organism in a pulsatile manner comprising the steps of: providing a housing having a wall defining a generally spherical interior, the housing having at least one intake port opening in communication with the interior of the housing and at least one discharge port opening in communication with the interior of the housing through which at least one blood fluid flows connecting at least one intake port opening and at least one discharge port opening to enable the circulation of at least one blood fluid through the living organism, rotating a first shaft mounted for rotation relative to the housing about a primary axis, wherein at least a portion of the first shaft extends through the housing wall; rotating at least one primary vane disposed within the interior of the housing that rotates about the primary axis; providing at least one secondary vane disposed within the interior of the housing and mounted to the primary vane on a first pivotal axis; and rotating the primary vane about the primary axis with the secondary vane pivotally oscillating between alternating relatively open and closed positions with respect to the primary vane; the housing, the primary vane, and the secondary vane defining at least one fluid chamber for containing fluid within the housing interior having a volume that varies as the primary vane is rotated about the primary axis.  
         [0019]     The instant invention also includes a method for simultaneously flowing a first fluid and a second fluid through the same pulsatile blood pumping system including at least the steps of: providing a housing having a wall defining a generally spherical interior, the housing having at least one port opening in communication with the interior of the housing through which fluid from a fluid source is allowed to flow; providing a first shaft mounted for rotation relative to the housing about a primary axis, wherein at least a portion of the first shaft extends through the housing wall; providing at least one primary vane disposed within the interior of the housing that rotates about the primary axis; providing at least one secondary vane disposed within the interior of the housing and mounted to the primary vane on a first pivotal axis; rotating the primary vane about the primary axis with the secondary vane pivotally oscillating between alternating relatively open and closed positions with respect to the primary vane, the housing, the primary vane, and the secondary vane defining a fluid chamber for containing fluid within the housing interior having a volume that varies as the primary vane is rotated about the primary axis; and providing a first fluid and a second fluid and connecting the first and second fluids to appropriate port openings to enable separate movement of the first and second fluids through the pulsatile blood pumping system.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]     For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:  
         [0021]      FIG. 1  is a front perspective view of a pulsatile blood pump, shown with the upper half of a housing of the pump exploded away to reveal internal components of the device;  
         [0022]      FIG. 2  is a perspective view of the lower half of the housing of the pump of  FIG. 1  with the internal components removed;  
         [0023]      FIG. 3  is a perspective view of a input shaft and primary vane assembly of the pump of  FIG. 1 , shown with the primary vane assembly exploded into two halves;  
         [0024]      FIG. 4  is a perspective view of a secondary vane assembly of the pump of  FIG. 1 , shown with the secondary vane assembly exploded into two halves;  
         [0025]      FIG. 5  is an exploded perspective view of a fixed second shaft assembly of the pump of  FIG. 1 ;  
         [0026]      FIG. 6  is a perspective view of a flow capacity control lever for rotating the second shaft of  FIG. 5 ;  
         [0027]      FIG. 7  is a cross-sectional view of the lever of  FIG. 6  taken along the lines  7 -- 7 ;  
         [0028]      FIG. 8A  is a detailed cross-sectional view of the pump of  FIG. 1 ;  
         [0029]      FIG. 8B  is a cross-sectional view of the pump of  FIG. 1 , showing various rotational axes of the device;  
         [0030]      FIG. 8C  is a schematical diagram of the pump housing showing the rotation of a control plane with respect to the pump housing;  
         [0031]      FIG. 9A  is a perspective view of the pump of  FIG. 1  shown with the upper half of the housing removed;  
         [0032]      FIG. 9B  is a front elevational view of the pump of  FIG. 9A ;  
         [0033]      FIG. 9C  is a top plan view of the pump of  FIG. 9A ;  
         [0034]      FIG. 9D  is a side elevational view of the pump of  FIG. 9A ;  
         [0035]      FIGS. 10A-10E  are sequenced perspective views of the pump of  FIGS. 9A-9D  with the control lever in the 0 degree position, as the input shaft of the pump is rotated 180 degree during the pump&#39;s operation;  
         [0036]      FIG. 11A  is a perspective view of the pump of  FIG. 1  shown with the upper half of the housing removed and the control lever in a 180-degree position;  
         [0037]      FIG. 11B  is a front elevational view of the pump of  FIG. 11A ;  
         [0038]      FIG. 11C  is a top plan view of the pump of  FIG. 11A ;  
         [0039]      FIG. 11D  is a side elevational view of the pump of  FIG. 11A ;  
         [0040]      FIGS. 12A-12E  are sequenced perspective views of the pump of  FIGS. 11A-11D , with the control lever in the 180 degree position, as the input shaft of the pump is rotated 180 degrees during the pump&#39;s operation;  
         [0041]      FIG. 13A  is a perspective view of the pump of  FIG. 1  shown with the upper half of the housing removed and the control guide in a neutral position.  
         [0042]      FIG. 13B  is a front elevational view of the pump of  FIG. 13A .  
         [0043]      FIG. 13C  is a top plan view of the pump of  FIG. 13A .  
         [0044]      FIG. 13D  is a side elevational view of the pump of  FIG. 13A .  
         [0045]      FIGS. 14A-14E  are sequenced perspective views of the pump of  FIGS. 13A-13D , with the control lever in the 90 degree or neutral position, as the input shaft of the pump is rotated 180 degrees during the pump&#39;s operation.  
         [0046]      FIG. 15  is a detailed cross-sectional view of a spherical pump operating with an exterior carrier guide ring.  
         [0047]      FIG. 16  is a detailed view of the exterior carrier ring of the device of  FIG. 15 .  
         [0048]      FIG. 17  is a detailed cross-sectional view of the pump of  FIG. 1  showing added structure to improve rigidity and the addition of internal coolant-lubricant or flushing lines.  
         [0049]      FIG. 18  is a detailed cross-sectional view of the pump of  FIG. 1  showing a different embodiment of added structure to improve rigidity and the addition of internal coolant-lubricant or flushing lines.  
         [0050]      FIG. 19  is a cross-sectional view of the pump of  FIG. 1 , showing an embodiment providing balanced forces across a secondary vane as the secondary vane approaches the relatively closed position with respect to the primary vane.  
         [0051]      FIGS. 20A-20E  are sequenced perspective views of the pump of  FIGS. 9A-9D  with the control lever in the 0 degree position, as the input shaft of the pump is rotated 180 degree during the pump&#39;s operation, showing the simultaneous flow of two fluids through the pump.  
         [0052]      FIG. 20F  is a view of the port openings only of  FIG. 20A-20E  to show the flow of two different fluids.  
         [0053]      FIG. 21  is a cross-sectional view of the pump of  FIG. 1 , showing the embodiments of simplified mechanism, tight tolerancing and fluid flushing to improve use of the fluid machine as a blood pump.  
         [0054]      FIG. 22  is a front perspective view of a pump similar to  FIG. 1  but showing the embodiment of a port insert.  
         [0055]      FIGS. 23A-23E  are sequenced perspective views of the pump of  FIGS. 9A-9D  with the control lever in the 0 degree position, as the input shaft of the pump is rotated 180 degree during the pump&#39;s operation, showing the simultaneous flow of two fluid streams at two different flow rates through the pump.  
         [0056]      FIG. 24  is a front perspective view of a pump similar to  FIG. 1  but showing the embodiment of an eccentric port insert.  
         [0057]      FIG. 25  is a front perspective view of a fluid pump, shown with the upper and lower halves of the housing of the pump exploded away and divided into quarters, and internal components of the device removed.  
         [0058]      FIGS. 26A-26E  are sequenced perspective views of the pump of  FIGS. 9A-9D  with the control lever in the 0 degree position, as the input shaft of the pump is rotated 180 degree during the pump&#39;s operation, showing only the volumes occupied by the fluid in the fluid chambers and fluid ports.  
         [0059]      FIG. 27  is a perspective view of the secondary vane of the present invention, depicting a first aspect of altering the vane shape to reduce shear forces on the fluid.  
         [0060]      FIG. 28  is a perspective view of the fluid volumes shown in  FIG. 26E , showing the embodiment of the vane shape being altered according to the first aspect depicted in  FIG. 27  to reduce shear forces on the fluid.  
         [0061]      FIG. 29  is a perspective view of the secondary vane of the present invention, depicting a second aspect of altering the vane shape to reduce shear forces on the fluid.  
         [0062]      FIG. 30  is a cross-sectional view of a port of the present invention depicting a third aspect to reduce shear forces on the fluid involving altering of the transitional surface between the housing and a port.  
         [0063]      FIG. 31  is a graphical representation of the variation of the volumes of two fluid chambers as the input shaft is rotated in the pump in an embodiment for assisting or replacing the pumping of a human heart.  
     
    
     DETAILED DESCRIPTION  
       [0064]     Referring to  FIG. 1  of the drawings, the reference numeral  10  generally designates a pulsatile blood pumping system of the type that can apply the improvements of the instant invention. The pump  10  is generally similar in construction to the device described in U.S. Pat. No. 6,241,493.  
         [0065]     The pump  10  includes a housing  12 , which is formed into two halves  14 ,  16 . Each half  14 ,  16  of the housing  12  is generally configured the same as the other and has a hemispherical interior cavity  18  ( FIG. 2 ), which forms a spherical interior of the housing  12  when the two halves  14 ,  16  are joined together. Each housing half or piece  14 ,  16  is provided with a circular flange  20  having a flat facing surface  21  which extends around the perimeter of the cavity  18  and which abuts against and engages the corresponding flange  20  of the other housing piece  14 ,  16 . The flange face  21  lies in a plane that generally divides the spherical housing interior  18  into two equal hemispherical halves when the housing halves  14 ,  16  are joined together.  
         [0066]     A fluid tight seal is formed between the housing halves  14 ,  16  when the halves  14 ,  16  are joined together. Formed in each housing piece  14 ,  16  are rear and front fluid ports  24 ,  26  that communicate between the exterior of the housing and the housing interior  18 . The fluid ports  24 ,  26  are circumferentially spaced apart approximately 90 degrees from the next adjacent port, with the approximate center of each fluid port being contained in a plane oriented perpendicular to the flange faces  21  and that bisects the interior of the housing  12  when the housing halves  14 ,  16  are joined together. The ports  24 ,  26  are positioned about 45 degrees from the flange faces  21  on each housing half  14 ,  16 .  
         [0067]     Formed at the rearward end of each housing half  14 ,  16  adjacent to the rearward port  24  is a recessed area  28  formed in the circular flange  20  for receiving a main input shaft  32  ( FIG. 1 ), which extends for a distance into the housing interior  18 . This shaft will be referred to as either the first or the input shaft. The primary axis or axis of rotation  33  of the input shaft  32  lies generally in the same plane as the flange faces  21 . An input shaft collar  34  extends outwardly from the housing halves  14 ,  16  and is provided with a similarly flanged surface  36  for facilitating joining the housing halves together.  
         [0068]     Located at the forward end of the housing  12  opposite the collar  34  in each housing half  14 , 16  is a recessed area  38  formed in the circular flange  20  to form a shaftway for receiving a second shaft  40  ( FIG. 1 ). A neckpiece  42  extends outwardly from the circular flange  20  and is also provided with a flanged surface  44  to facilitate joining of the housing halves together.  
         [0069]     The housing  12  houses primary and secondary vane assemblies  52 ,  54 , respectively. Referring to  FIG. 3 , the primary vane assembly, designated generally at  52 , is formed into two halves  56 ,  58 . The primary vane halves  56 ,  58  are generally configured the same, each having a generally flat inner surface  59  that abuts against the inner surface of the other half. The primary vane halves  56 ,  58  each have opposite vane members  62 ,  64 , that are joined together at opposite ends by integral hinge portions  66 ,  68  to define a central circular opening  69 . When the primary vane halves  56 ,  58  are joined together, the vane members  62  and  64  form a single opposing vane.  
         [0070]     The vane members  62  are each provided with an input shaft recess  60  formed in the flat surface  59  for receiving and coupling to the input shaft  32  when the vane halves  56 ,  58  are joined together. The primary vane assembly  52  is rigidly coupled to the input shaft  32  so that rotation of the input shaft  32  is imparted to the primary vane assembly  52  to rotate the combined vanes  56 , 58  within the housing interior  18 .  
         [0071]     Similarly, the vane members  64  are provided with a second shaft recess  70  formed in the flat surface  59  for receiving the second shaft  40 . The second shaft recess  70  is configured to allow the primary vane assembly  52  to freely rotate about the second shaft  40 . The outer ends of the vane members  62 ,  64  have a generally convex spherical lune surface configuration corresponding to the spherical interior  18  of the housing  12 .  
         [0072]     The hinge portions  66 ,  68  are each provided with a stub shaft recess  72 . A stub shaft  74  is shown provided with the hinge portion  66  of the vane half  56 . This stub shaft  74  may be integrally formed with one of the vane halves  56 ,  58  or may be a separate member that is fixed in place. As is shown, the stub shaft  74  projects a distance outward beyond the hinge portion  66 . The hinge portions  66 ,  68  are each squared or flat along the outer side edges  73 .  
         [0073]     Referring to  FIG. 4 , the secondary vane assembly  54  is also shown being formed in two halves  76 ,  78 , each half  76 ,  78  being generally similar in construction. The secondary vane halves  76 ,  78  are generally configured the same, each having an inner surface  80 , which is generally flat and which abuts against the inner surface of the other vane half. The secondary vane halves  76 ,  78  each have opposite vane members  82 ,  84 , that are joined together at opposite ends by integral hinge portions  86 ,  88  to define a central circular opening  90 . When the secondary vane halves  76 ,  78  are joined together; the vane members  82  and  84  form a single opposing vane.  
         [0074]     The vane members  82 ,  84  are each provided with pivot post recesses  92  formed in the inner surfaces  80  of each vane half  76 , 78 . The outermost ends of the vane members  82 ,  84  also have a generally convex spherical lune surface configuration corresponding to the spherical interior  18  of the housing  12 .  
         [0075]     The hinge portions  86 ,  88  are each provided with a stub shaft recess  94 . A second stub shaft  96  is shown provided with the hinge portion  88  of the vane half  78 . This stub shaft  96  may be integrally formed with one of the vane halves  76 ,  78  or may be a separate member that is fixed in place. As is shown, the stub shaft  96  projects a distance inward from the hinge portion  88 . Both the hinge portions  86 ,  88  are squared or flat along the inner side edges  89  to correspond to the flat outer side edges  73  of the hinge portions  66 ,  68  of the primary vane halves  56 ,  58 . The shapes of narrow ridges  83  generally complement the shape of the exterior surfaces of hinge portions  66 ,  68 . The exterior of the hinge portions  86 ,  88  are in the form of a convex spherical segment or sector that is contoured smoothly with the curved surface of the outer ends of the vane members  82 ,  84 , and corresponds in shape to the spherical interior  18  of the housing  12 .  
         [0076]     When the primary and secondary vanes  52 ,  54  are coupled together ( FIG. 3 ) and mounted to the main input shaft  32 , the stub shafts  74 ,  96  are generally concentric. The stub shaft  74  of the primary vane assembly  52  is received within the recesses  94  of the hinge portion  86  of the secondary vane assembly  54  to allow relative rotation of the secondary vane assembly  54  about the stub shaft  74 . Likewise, the stub shaft  96  of the secondary vane assembly  54  is received within the recesses  72  of the hinge portion  68  of the primary vane assembly  52  and allows relative rotation of the primary vane assembly  52  about the stub shaft  96 . In this way, the primary and secondary vanes assemblies  52 ,  54  remain interlocked together while the secondary vane assembly  54  is allowed to pivot relative to the primary vane assembly  52  about a first pivotal axis  35  that is perpendicular to the primary axis  33  of the input shaft  32 .  
         [0077]      FIG. 5  shows an exploded view of a fixed second shaft or race assembly  100 . The second shaft assembly  100  is comprised of the cylindrical second shaft  40 , which is received in the recesses  38  of the housing halves  14 ,  16 , as discussed previously. The cylindrical second shaft  40  is coaxial with the primary axis  33  of the input shaft  32  when mounted to the housing  12 . At the inner end of the shaft  40  is a spherical shaft portion  102  in the form of a sphere section. Projecting from the inner side of the spherical shaft portion  102  is a cylindrical carrier ring shaft  104 . The longitudinal axis of the carrier ring shaft  104  is oriented at an oblique angle with respect to the axis of shaft  40 . This angle may vary, but is preferably between about 30 degrees to 60 degrees, with 45 degrees being the preferred angle. A boss  106  projects from the end of the shaft  104  to facilitate mounting of an end cap  108 , which is in the form of a spherical section. The end cap  108  is provided with a recess  110  for receiving the boss  106  of shaft  104 . In the embodiment shown, a pair of threaded fasteners  112 , such as screws or bolts, which are received within eccentrically disposed threaded bolt holes  114  formed in the boss  106 , are used to secure and fix the end cap  108  to the shaft  104 . Two or more fasteners may be used. Because the fasteners are eccentrically located with respect to the axis of the shaft  40 , they prevent relative rotation of the end cap  108  with respect to the shaft  40 .  
         [0078]     The end cap  108  is used to secure a central carrier ring  116 , which is rotatably mounted on the carrier ring shaft  104 . The carrier ring  116  is configured with an outer surface in the form of a spherical segment so that when the carrier ring  116  is mounted on the shaft  104  and the end cap  108  is secured in place, the combination of the spherical portion  102 , carrier ring  116  and end cap  108  generally form a complete sphere that is joined to the end of the shaft  40 . This complete sphere is designated generally as central ball  115 . The diameter of this sphere generally corresponds to the diameter of the central openings  69 ,  90  of the primary and secondary vane assemblies  52 ,  54 , respectively, to allow the vane assemblies  52 ,  54  to rotate about this spherical portion of the second shaft assembly  100 , while being in close engagement thereto. The carrier ring  116  is approximately centered between the spherical portion  102  and the end cap  108 .  
         [0079]     The carrier ring  116  is provided with oppositely projecting pivot posts  118  that project radially outward from the outer surface of the carrier ring  116 . The posts  118  are concentrically oriented along an axis that is perpendicular to the axis of rotation of the carrier ring  116 . The posts  118  are received within the pivot post recesses  92  of the secondary vane halves  76 ,  78  when the vane assembly  50  is mounted over the spherical portion of the second shaft assembly  100  formed by the spherical portion  102 , carrier ring  116  and end cap  108 .  
         [0080]     Coupled to the second shaft  40  opposite the spherical portion  102  is a flow capacity control lever  120  for manually rotating the shaft  40  and spherical portion  102 . The control lever  120 , shown in more detail in  FIGS. 6 and 7 , has a generally circular-shaped body portion  122 . A lever arm  124  extends from the body portion  122 . Formed generally in the center of the body portion  122  is a bolt hole  126  for receiving a bolt  128  for fastening the lever  120  to the shaft  40  by means of a central, threaded bolt hole  130  formed in the outer end of the shaft  40 . Spaced around bolt hole  126  are dowel holes  132  which correspond to dowel holes  134  formed in the shaft. Dowels  136  are received within the dowel holes  132 ,  134  to prevent relative rotation of the control lever  120  with respect to the shaft  40 . Although one particular method of coupling the lever  120  to the shaft  40  is shown, it should be apparent to those skilled in the art that other means may be used as well. Control lever  120  can have smaller profiles as shown by control lever  120 A shown later in  FIGS. 9, 11 , and  13 . The control lever acts as an adjustable vane guide bearing member to oscillate the secondary vane to various opening positions relative to the primary vane.  
         [0081]     An arcuate slot  138  that extends in an arc of about 180 degrees is formed in the body portion  122  of the lever  120  for receiving a setscrew or bolt  140 . The arcuate slot  138  overlays a threaded bolt hole  142  formed in the housing neck piece  42  of the housing half  14 , when the shaft assembly  100  is mounted to the housing  12 . The setscrew  140  is used to fix the position of the lever  120  to prevent rotation of the shaft  40  once it is in the desired position. By loosening the setscrew  140 , the lever  120  can be rotated to various positions to rotate the shaft assembly  100 , with the setscrew  140  sliding within the slot  138 .  
         [0082]      FIG. 8A  is a longitudinal cross-sectional view of the assembled pump  10  shown in more mechanical detail. Although one particular embodiment is shown, it should be apparent to those skilled in the art that a variety of different configurations and components, such as bearings, seals, fasteners, etc., could be used to ensure the proper operation of the pump  10 . The embodiment described is for ease of understanding the invention and should in no way be construed to limit the invention to the particular embodiment shown.  
         [0083]     As can be seen, the input shaft  32  extends through the collar  34  at the rearward end of the housing  12 . The collar  34  defines a cavity  144  that houses a pair of longitudinally spaced input shaft roller bearing assemblies  146 ,  148 . Each of the roller bearing assemblies  146 ,  148  is comprised of an inner race  154  and an outer race  156 , which houses a plurality of circumferentially spaced tapered roller bearings  158  positioned therebetween. Spacers  150 ,  152  maintain the roller bearing assemblies  146 ,  148  in longitudinally spaced apart relationship along the input shaft  32 , with the inner race  154  of the roller bearing assembly  148  abutting against an outwardly projecting annular step  160  of the drive shaft  32 , and the outer race  156  abutting against a inwardly projecting annular shoulder  162  of the collar  34 .  
         [0084]     A bearing nut  164  threaded onto a threaded portion  165  of the input shaft  32  abuts against the inner race  154  of bearing assembly  146  and preloads the inner races  154 . Bolted to the end of the collar  34  is a bearing retainer ring  166 . The bearing retainer ring  166  abuts against the outer race  156  of bearing assembly  146  and preloads the outer bearing races  156 . The retainer ring  166  also serves to close off the cavity  144  of the housing collar  34 . An annular seal  168  seated on the annular lip  170  of the retainer ring  166  bears against the exterior of the bearing nut  164  to prevent leakage of lubricant from the bearing cavity  144 .  
         [0085]     Located within the recessed area  28  and surrounding the input shaft  32  is a washer  172  that abuts against the inner race  154  of the bearing assembly  148 . A compressed coiled spring  174  abuts against the washer  172  and bears against a carbon sleeve  176 . The sleeve  176  is provided with an O-ring seal  178  located within an inner annular groove of the sleeve  176 . The sleeve  176  abuts against a fixed annular ceramic plate  180 , which seats against an annular lip  182  projecting into the recessed area  28 . The low coefficient of friction between the interfacing carbon sleeve  176  and ceramic plate  180  allows the sleeve  176  to rotate with the input shaft  32 , while providing a fluid-tight seal to prevent fluid flow between the pump interior  18  and the collar cavity  144 .  
         [0086]     The input shaft  32  extends into the interior  18  of the housing  12  a short distance and is coupled to the primary vane assembly  52  within the recesses  60  formed in vane halves  56 ,  58 . The end of the shaft  32  is provided with a annular collar  184  received in grooves  186  formed in the recesses  60  of the vane halves  56 ,  58  to prevent relative axial movement of the shaft  32  and vane assembly  52 . Relative rotational movement between the vane assembly  52  and shaft  32  is prevented by key members  188  being received in key slots of the vane assembly  52  and shaft  32 , respectively.  
         [0087]     Surrounding the second shaft portion  40  within the recess  70  of the primary vane assembly  52  are longitudinal roller bearings  206 . Seals  208 ,  210  are provided at either end of the roller bearing assembly  206  to prevent fluid from escaping along the second shaft  40  through recesses  70 . A static O-ring seal  212  surrounds the shaft  40  at the interface of the lever arm  120  with housing neckpiece  42  to prevent fluid loss through shaftway  38 .  
         [0088]     Surrounding the carrier ring shaft  104  are roller bearing assemblies  214 ,  216 . Each roller bearing assembly  214 ,  216  is comprised of an inner race  218  and an outer race  220  with a plurality of tapered roller bearings  222  therebetween. The inner races  218  of assemblies  214 ,  216  are spaced apart by means of a spacer  224 . The inner face of the carrier ring  116  rests against the outer races  220 . An annular web  226  projects radially inward from the inner annular face of the carrier ring  116  and serves as a spacer between the outer races  220  and prevents axial movement of the carrier ring  116  along the shaft  104 . For spherical pump configurations that have the equivalent to carrier ring  116  on the outside of housing  12 , the equivalent ring is preferably manufactured in two or more sections to allow ease of assembly of the pump. These sections may be, for example, two semicircular segments that divide the equivalent ring approximately across the diameter, or two circular segments that join at the center circumferential plane of the equivalent ring. The sections are then joined with fasteners.  
         [0089]     Lip seals  230 ,  232  provided in inner faces of the end cap  108  and spherical portion  102 , respectively, engage the side edges of the carrier ring  116  to prevent fluid from entering the annular space surrounding the carrier ring shaft  104  where the bearing assemblies  214 ,  216  are housed and which contains a suitable lubricant for lubricating the bearing assemblies  214 ,  216 . At lower rates of rotation a lubricant or coolant may not be needed on a continual basis.  
         [0090]     Axially oriented roller bearings  234  surround the pivot posts  118  to allow the secondary vanes  54  to rotate. Fluid seals  236  are provided at the base of posts  118 . Radially oriented thrust bearings  238  located at the terminal ends of posts  118  and are held in place by thrust caps  240 . The thrust caps  240  are held in place within annular grooves  242  formed in the pivot post recesses  92 .  
         [0091]     As can be seen, the outer ends of the primary vanes  52  and secondary vanes  54  are in close proximity or a near touching relationship to provide a clearance with the interior  18  of the housing  12 . There is also a slight clearance between the spherical end portion of the fixed second shaft assembly  100  and the central openings  69 ,  90  of the primary and secondary vanes  52 ,  54 . These clearances should be as small as possible to allow free movement of the vanes  52 ,  54  within the interior  18 , while minimizing slippage or fluid loss across the clearances, and to allow for differences in thermal expansion between the housing  12 , the vanes  52 ,  54  and the spherical portion  102  and end cap  108 .  
         [0092]      FIG. 8B  illustrates the relationship of the various rotational axes of the pump components. As shown, carrier ring  116  rotates about the carrier ring axis  246 . The axis  246  intersects the primary vane axis  33  at an oblique angle and defines a control plane  247 . The secondary vane  54  pivots about the pivot posts  118  about a secondary vane second pivotal axis  245  that remains perpendicular to the carrier ring axis  246 . This second pivotal motion of the secondary vane is simultaneous with the pivotal motion of the secondary vane about the first pivotal axis perpendicular to the primary axis, which was discussed earlier.  
         [0093]      FIG. 8C  shows an end view of the pump  10  as viewed along the primary axis, and showing the various orientations of the timing or control plane  247  that may be achieved by rotating the second shaft assembly  100 , as is described below.  
         [0094]     Referring to  FIGS. 9-14 , the pump  10  is shown with the upper housing  16  removed to reveal the internal components of the pump  10 . The ports  24 ,  26  of the upper housing  16 , however, are shown to indicate their relative position if the upper housing  16  were present. Further, although the input shaft  32  may be rotated in either a clockwise or counterclockwise direction, for purposes of the following description the operation of the pump  10  is described wherein the input shaft  32  is rotated in a clockwise direction, as indicated by the arrow  244  in  FIG. 9A .  
         [0095]     Referring to  FIGS. 9A-9D , the pump  10  is shown with control guide  120 A rotated so that the carrier ring or secondary axis  246  is oriented at a 45 degree angle to the right of the primary axis  33 , as viewed in  FIG. 9C , so that the control plane  247  ( FIGS. 8B  and  8 C) lies in a substantially horizontal plane that is generally the same or parallel to the plane of the flanges  20  which bisect the housing  12 .  
         [0096]      FIGS. 9A-9D  show the primary and secondary vanes  50 ,  98  with the secondary vane  98  at a central intermediate position of its stroke. The forward port  26  of the upper housing  16  and the rearward port  24  of the lower housing  14  serve as discharge ports, while the rearward port  24  of the upper housing  16  and the forward port  26  of the lower housing  14  serve as intake ports. The primary and secondary vanes  50 ,  98  divide the spherical interior  18  of the housing into four chambers, as defined by the spaces between the primary and secondary vanes  50 ,  98  designated at  248 ,  250 . Although not visible, corresponding spaces or chambers would be present in the lower housing half  14 .  
         [0097]      FIGS. 10A-10E  show sequenced views of the pump  10  in operation with the control lever  120  in the 0 degree position as the input shaft  32  is rotated through 180 degrees of revolution. For ease in describing the operation, the opposing secondary vanes are labeled  98 A,  98 B, with the opposing primary vanes being designated  50 A,  50 B. As shown in  FIGS. 9A and 9C , as the input shaft  32  is rotated, the primary and secondary vanes assemblies  52 ,  54  are rotated about the primary axis  33  within the housing interior  18 . Because the secondary vane assembly  54  is pivotally mounted to the carrier ring  116  by means of pivot posts  118 , the secondary vane assembly  54  causes the carrier ring  116  to rotate on the carrier ring shaft  104  (not shown) about the carrier ring axis  246 . Because the carrier ring axis  246  is oriented at an oblique angle with respect to the primary axis  33 , the carrier ring  116  causes each secondary vane  98 A,  98 B to reciprocate or move back and forth between a fully open position and a fully closed position.  
         [0098]      FIG. 10A  shows the pump  10  with the secondary vane  98 A in the fully closed position with respect to primary vane  50 A. In the fully closed position, the secondary vane  98 A abuts against or is in close proximity to the primary vane  50 A, so that the volume therebetween is minimal. In contrast, with respect to the opposing primary vane  50 B, the vane  98 A is in a fully open position so that the space between the vanes  98 A and  50 B is at its maximum. Any fluid within the space between vanes  98 A,  50 A is mostly fully discharged through the port  26  of the upper housing. There is a slight overlap or communication of the interfacing primary and secondary vanes  50 A,  98 A with the port  26  along its edge when in the fully closed position to accomplish this. In one aspect of the invention the primary vanes  50 A,  50 B are sized to completely cover and seal the ports  24 ,  26  so that slight rotation beyond this point causes the primary vanes  50 A,  50 B to close off communication with the chambers  248 ,  250  momentarily during rotation.  
         [0099]      FIG. 10B  illustrates the pump  10  with the shaft  32  rotated approximately 45 degrees from that of  FIG. 10A . Here the secondary vane  98 A begins to move to the open position with respect to the primary vane  50 A. This draws fluid into the opening space through the lower inlet port  26  of the lower housing  14 . The secondary vane  98 B also begins to move to the closed position with respect to the primary vane  50 A. Fluid located in the chamber between the primary vane  50 A and secondary  98  is thus compressed or forced out of the upper discharge port  26  of the upper housing  16 .  
         [0100]     In a like manner, fluid located between the secondary vane  98 A and primary vane  50 B is discharged through the lower port  24  (not shown) of the lower housing  14 , as the secondary vane  98 A begins to move to the closed position with respect to the primary vane  50 B. Fluid is also drawn through the inlet port  24  of the upper housing  16  as the secondary vane  98 B is moved towards an open position with respect to the primary vane  50 B.  
         [0101]      FIGS. 10C and 10D  show further rotation of the shaft  32  in approximately 45-degree increments. When the second shaft assembly  100  is in the 0 degree position, the timing is such that the chambers created by the primary and secondary vanes  50 ,  98  remain in continuous communication with ports  24 ,  26  during generally the entire stroke of the vane  50  between the closed and open positions. In this way fluid continues to be drawn into or discharged from the chambers as the secondary vanes  98  are moved to either the open or closed positions during rotation of the shaft  32 .  
         [0102]      FIG. 10E  shows the pump  10  after the shaft  32  is rotated 180 degrees. The secondary vane  98 B is in the fully closed position with respect to the primary vane  50 A, just as the secondary vane  98 A was when the shaft  32  was at the 0 degree position in  FIG. 10A . By continuing to rotate the shaft  32 , the process is repeated so that the fluid is taken into the pump, pressurized and discharged by the reciprocation of the secondary vane between the open and closed positions, which is caused by the rotation of the carrier ring  116  about its oblique carrier ring axis  246 .  
         [0103]     By rotating the fixed second shaft assembly  100  to different fixed positions, the flow of fluid through the pump  10  can be adjusted and even reversed without changing the direction of rotation of the input shaft  32 .  FIG. 11A  shows the pump  10  with control guide  120 A rotated so that the carrier ring axis  246  is oriented at an approximately 45 degree angle to the left of the primary axis  33 , as viewed in  FIG. 11C , or about 90 degrees from that orientation of the axis  246  as shown in  FIG. 9C . In this position, the control plane  247  lies in a substantially horizontal plane that is generally the same or parallel to the plane of the flanges  20  which bisect the housing  12 .  
         [0104]     In the configuration of  FIGS. 11A-11D , the forward port  26  of the upper housing  16  and the port  24  of the lower housing  14  serve as intake ports, while the port  24  of the upper housing  16  and the port  26  of the lower housing  14  serve as discharge ports.  
         [0105]      FIGS. 12A-12E  show sequenced views of the pump  10 , with the control lever  120  rotated to the 180 degree position, as the input shaft  32  is rotated through 180 degrees of rotation. In  FIG. 12A , the pump  10  is shown with the secondary vane  98 A in the fully closed position against the primary vane  50 A. The vane  98 A is also in a fully open position with respect to primary vane  50 B. Referring to  FIG. 12B , as the input shaft  32  is rotated, as shown by the arrow, the secondary vane  98 A begins to move to the open position with respect to the primary vane  50 A. The space or chamber formed between the secondary vane  98 A and vane  50 A is in continuous communication with the port  26  of the upper housing  16  as it is moved to the open position. The increasing volume of this chamber as the shaft  32  is rotated, as shown in  FIGS. 12C and 12D , draws fluid through the upper forward port  26 . As this is occurring, the secondary vane  98 B moves to the closed position with respect to the primary vane  50 A forcing fluid between these vanes  98 B,  50 A through the forward port  26  of the lower housing  14 .  
         [0106]      FIG. 12E  shows the pump after the shaft  32  is rotated 180 degrees. The secondary vane  98 B is now in the closed position with respect to the primary vane  50 A so that the process can be repeated. With the lever  120  in the 180 degree position, fluid is also discharged through rearward port  24  in the upper housing  16  and introduced through rearward port  24  of the lower housing  14  in the similar manner as that already described with respect to the forward ports  26 . The ports  24 ,  26  remain in generally constant communication with one of the chambers created by the vanes  50 ,  98  during the entire stroke of the vane  98  between the open and closed positions.  
         [0107]      FIGS. 13A-13D  illustrate the pump  10  in an intermediate or neutral mode, with control guide  120 A oriented so that the carrier ring axis  246  lies in a plane perpendicular to the housing flanges  20  and is oriented at an angle of 45 degree below the primary axis  33 , as viewed in  FIG. 13D . In this orientation, the control plane  247  is in the 90 degree or vertical position, as seen in  FIG. 8C . In this mode, the ports  24 ,  26  only communicate approximately 50% of the time with the chambers created by the vanes  50 ,  98 .  
         [0108]      FIG. 14A  shows the secondary vane  98  in a center or intermediate position, with the primary vane  50  oriented so that it covers and seals the ports  24 ,  26 . As the input shaft  32  rotates from this intermediate position, as shown in  FIG. 14B , the port  26  of the upper housing  16  begins to communicate with the chamber between secondary vane  98 B and primary vane  50 A, and the port  26  of the lower housing  14  communicates with the chamber between the secondary vane  98 A and primary vane  50 A. As the secondary vane  98 B is moved towards the open position with respect to the primary vane  50 A, some fluid is drawn through the port  26  of the upper housing  16 . In a similar manner, the secondary vane  98 A is moved to the closed position with respect to the primary vane  50 A so fluid therein is forced out of the lower port  26 .  
         [0109]      FIG. 14C  shows the secondary vane  98 B in the fully open position with respect to the primary vane  50 A. The secondary vane  98 A, which is hidden from view, is in the fully closed position with respect to primary vane  50 A, with the closed space between the primary vane  50 A and secondary vane  98 A being in communication with the lower forward port  26  of the lower housing  14 .  
         [0110]     As the shaft  32  is rotated further, as seen in  FIG. 14D , some fluid is forced out of the upper housing  16  through port  26  as the secondary vane  98 B now moves to the closed position with respect to vane  50 A. Fluid is also drawn in through the lower port  26  as the secondary vane  98 A is moving to the open position in relation to the primary vane  50 A.  
         [0111]      FIG. 14E  shows the pump  10  after rotation of the shaft  32  180 degrees from its original position of  FIG. 14A . The secondary vane  98  is once again in the intermediate position, like that of  FIG. 14A , and the process is repeated. With the control lever  120  in the 90 degree position, as described, the ports  26  of the lower and upper housing  14 ,  16  only communicate with the chambers defined by the primary and secondary vanes  50 ,  98  approximately 50% of the time. This results in equal volumes of fluid being both drawn and discharged through each of the forward ports  26  in the upper and lower housing during this neutral mode. The operation is the same with respect to the fluid flow through the rearward ports  24  in the lower and upper housing  14 ,  16 . The net fluid flow through the pump  10  is therefore essentially zero.  
         [0112]     By rotating the control lever  120  between the 0 degree and 180 degree positions, the fluid flow can be increased or decreased precisely in a smooth and continuous manner, and can be directed in either flow direction. This is due to the increased amount of time that the inlet ports and discharge ports communicate with the chambers  248 ,  250  formed by the vanes  50 ,  98  during the expansion and compression strokes, respectively, of the secondary vane  98 . Thus, for example, as the lever  120  is rotated from the 90 degree or neutral position towards the 0 degree position of  FIG. 10A , the length of time the forward port  26  of the upper housing  16  communicates with the chamber formed by the primary vane  50 A and secondary vanes  98 , as the secondary vanes  98  are moved to the closed position, is lengthened, resulting in more and more fluid flow through this port. As described previously, when the lever is at the full 0 degree position, the port  26  of the upper housing  16  is in communication with the chamber formed by the primary vane  50 A and secondary vanes  98  during almost the entire compression stroke of the secondary vanes  98  with respect to the vane  50 A so that full flow is achieved when the pump  10  is in this mode. Similar results in the reverse-flow direction are achieved by rotating the lever  120  between the 90-degree and the 180-degree position, which is shown in  FIG. 12A .  
         [0113]     Other means could be provided for rotating the second shaft assembly  100 . For instance, the shaft  40  could be coupled to a worm and worm gear to rotate the second shaft to various positions. This in turn could be coupled to a controller that would cause the second shaft assembly to be rotated to automatically control and adjust the fluid flow or capacity of the pump  10 . In this manner the flow capacity and even the direction of flow can be automatically adjusted remotely from the pump. A pump configured with this aspect of control of the second shaft assembly position can be seen in  FIGS. 22, 24 , and  25 , where controller  119  turns worm gear  121  to rotate gear  120 C attached to shaft  40 . It should be recognized that other controller implementations could be used for remote control of the fixed shaft.  
         [0114]     The pump described above is based on an internal carrier ring assembly that guides the reciprocating action of the secondary vane. Alternately, these types of spherical pumps can have the guide carrier ring mounted in an exterior manner. U.S. Pat. No. 5,199,864 discloses a somewhat similar pump to that of U.S. Pat. No. 6,241,493 and also describes an embodiment (the “second embodiment”) that uses an exterior carrier ring to guide the reciprocal motion of the vanes. In one particular alternative embodiment (the “second” embodiment) which is illustrated in  FIGS. 15-16 , a larger diameter collar  312  having inwardly protruding spindles  387  and  388  serves as the means for controlling reciprocation of secondary member  330  relative to rotation of primary member  320 . The inside diameter of collar  312  matches the inside diameter of the spherical interior surface  274  of housing  370  in order to provide a flush spherical surface. The housing  370  is modified to define an angular raceway  400  between two halves of housing  370  for receiving collar  312  therein. Also received within raceway  400  are washer-like bearings  385  and  386  for enabling rotation of collar  312  within raceway  400 . The housing  370  is formed in two halves that are joined by conventional means along raceway  400  for enabling assembly of collar  312  and bearings  385  and  386  within raceway  400 . A central member  333  provides the pivotal engaging surface between primary member  320  and secondary member  330 .  
         [0115]     The other features of the structure and operation of this external carrier ring design are substantially the same as in U.S. Pat. No. 6,241,493 except, of course, changes in the interior surfaces of vanes  321 ,  322 ,  331  and  332  are preferably modified to accommodate central member  133 . Similarly, the housing  370  of the second embodiment is modified to accommodate for raceway  400  therein, to produce the construction shown in  FIG. 15 . Many of the improvement embodiments of the instant invention have application in this type of exterior carrier ring design also.  
         [0116]     The use of the prior art machines as described earlier was limited in its use as a blood pump, in that they either provided an undesirably complex mechanism and/or did not adequately address issues related to blood clotting. One key to avoiding clotting is to eliminate areas where blood flow can become stagnant. The instant invention is quite useful in that all or nearly all of the volume of a fluid chamber is expelled with each relative opening and closing of primary and secondary vanes, insuring that blood flow cannot become stagnant in the fluid chamber. Additionally, the surface of spherical interior  118  of housing  12  is continually being swept by the motion of the exterior portions of vanes  52 ,  54 , and the mutually facing surfaces of vanes  52 ,  54  are repeatedly brought within close proximity to each other with every oscillating motion of secondary vane  54 . In short, there is no blood-contacting surface within the housing  12  of pump  10  whereon flow can become stagnant, which feature greatly aids in the prevention of thrombosis. In a first embodiment for preventing blood clotting,  FIG. 21  shows a simplified rotating mechanism adapted from the embodiment shown in  FIG. 17 . In this embodiment, the rotation of carrier ring  116  about the carrier ring axis is optionally slidingly facilitated by washer-shaped bearings  117 A,  117 B. To prevent the clotting of blood, which clots can migrate to other areas of the blood stream (thromboembolisms), the gap between carrier ring  116  and spherical shaft portion  102  and the gap between carrier ring  116  and end cap  108 A, or optionally the gaps between the carrier ring  116  and bearings  117 A,  117 B and the gap between bearing  117 A and spherical shaft portion  102  and the gap between bearing  117 B and end cap  108 A are preferably less than the approximate diameter of a red blood cell. Additionally, the gap between the cylindrical surfaces of pivot posts  118  and the corresponding recesses  92  of secondary vane halves  76 ,  78  is preferably less than the approximate diameter of a red blood cell. As can be seen, many of the moving parts shown in  FIG. 17  have been removed or replaced in this embodiment, e.g. bearings  222  and fasteners  122 , the latter of which have been replaced by threads  108 B included on carrier ring shaft  104  to receive modified end cap  108 A in a manner taught by Stecklein in U.S. Pat. No. 5,199,864. This simpler mechanism reduces the complexity of the pump design, and is facilitated by the fact that the pump of the instant invention has a relatively low rotation rate of the input shaft  32 , and alternatively may also be employed with the carrier ring on the outside of the housing interior, also as taught by Stecklein in U.S. Pat. No. 5,199,864.  
         [0117]     In a second embodiment for preventing blood clotting,  FIG. 17  shows a mechanism for continuously flushing, cooling and/or lubricating moving interfaces of the instant invention, with a fluid flushing line running through the input shaft, filling the interior sections of the central ball  115 , including one or more of the moving interfaces, and then flowing out through fixed shaft  40 . This is shown as the dark lines beginning at point  137  and exiting shaft  40  at point  139 . Alternatively, this fluid could flow in the opposite direction, feeding in through shaft  40  and out through point  137 . The flushing fluid could be blood, blood plasma, or any of the various fluids known to be compatible with the human biological system, and could be supplied from fluid chambers within pump  10 , from external connections to the vascular system, or from sources external to the body. Being biocompatible with the recipient, the flushing fluid could flow in limited amounts into the bloodstream of the recipient without adverse effects. This flushing mechanism may also be readily implemented in the simplified embodiment depicted in  FIG. 21 .  
         [0118]     The use of the prior art machines as described earlier was also limited in its use as a blood pump, in that they cause excessive shear forces on the fluid as the fluid flows through the pump. One depiction of such excessive shear forces is provided in  FIGS. 26A-26E , which approximately correspond to  FIGS. 10A-10E  of the description of the prior art, showing only the fluid volumes defined by chambers  301 - 304 , as described in greater detail below with reference to  FIGS. 20A-20E , and the upper and lower port fluid volumes  24 A,  26 A are defined by the interior of upper and lower ports  24 ,  26  respectively. As the input shaft  32  (not shown) rotates about its axis in the clockwise direction as shown in  FIG. 20A , the fluid chamber  304  decreases from its maximum volume depicted in  FIG. 26A  near to its minimum volume as depicted in  FIG. 26E . As the volume of fluid chamber  301  approaches its minimum, fluid in chamber  301  near upper port fluid volume  26 A necessarily has a greater velocity (depicted by size of arrow  313 ) than the velocity  311  of the fluid furthest from upper port fluid volume  26 A. This is because of the fact that the cross-sectional area provided perpendicular to the direction of fluid flow  313  near the port is roughly the same as the cross-sectional area provided perpendicular to the direction of fluid flow  311 , while the cumulative flow of all points further from the port than the location of  313  pass through the position near arrow  313 . This greater velocity  313  near the port interacts with the vane walls in a way that creates increased shear forces on the fluid in the vicinity of arrow  313 .  
         [0119]     To reduce the shear forces just mentioned, it is necessary to modify one or more surfaces of the vane from the standard shape taught in the prior art, which will be characterized generally as an “orange section”, with two main planar faces that generally mate with faces on opposing vanes. In the aspects of sheer reduction hereafter mentioned involving alteration of the vanes, said alteration is generally a modification on (or of) at least one of the said vane faces. A first aspect of the instant invention that reduces the above-mentioned shear forces provides vane shapes such that the distance between proximal primary vane and secondary vane at locations nearer the port are greater than the distance between proximal primary vane and secondary vane at locations further from the port. One depiction of this embodiment is shown in  FIG. 27 , where a vane face of secondary vane  98 B is altered according to surface  306 , where the plane of the surface of secondary vane  98 B facing the surface of primary vane  50 A has been rotated slightly about an axis which is coincident with both point  241  and the center point of center ball  115 , with the original surface  305  being represented with dotted lines for comparison. As shown in  FIG. 28 , the fluid near upper port  26 A has a decreased velocity  312 A, and therefore a decreased shear rate in the fluid at that location.  
         [0120]     With reference to  FIG. 29 , a second aspect of the instant invention for reducing shear forces alternatively provides at least one channel  307  in the vane surface  305 , which channel allows fluid at points removed from the port to flow along paths  308 A and  308 B which are relatively perpendicular to and shorter than the more direct paths  309  along the surface  305  to the discharge port. The above two embodiments may be combined by providing channels  307  whose depth is tapered so that the depth of the channel  307  at a point closer to the port is deeper than the depth of the channel  307  at a point further from the port. Likewise, channel  307  can be tapered in its width so that it is larger near the port. As would readily be apparent to those skilled in the art, the same objective of reducing shear forces on blood as described above may be obtained by any of a variety of combinations of modifications in the shape, size or surfaces of primary vanes  50 A,  50 B and secondary vanes  98 A,  98 B.  
         [0121]     With reference to  FIG. 30 , a third aspect of the instant invention for reducing shear forces additionally provides a curvilinear tapered portion  25  of one or more ports  24 ,  26  to reduce shear due to transitions between the housing surface and the interior of the port. Reduction of shear forces on fluid flowing between the housing interior  18  can be provided by a variety of different transitions between the housing interior  18  surface and the interior surface of the ports  24 ,  26  as would be apparent to those skilled in the art.  
         [0122]     The present invention improves greatly over prior art devices in its use as an artificial heart or heart assist device. In one embodiment of the present invention, pump  10  is used as an internally implanted or extracorporeally connected assist or replacement to one or both ventricles of the human heart. In a preferred embodiment, pump  10  is sized to provide flow and pulsation rates that match the typical requirements of the recipient. In one example of this particular embodiment, and with reference to  FIGS. 1, 3 ,  4 ,  21 , a blood pumping system is sized to provide pulsatile flow for a recipient whose normal requirements are approximately five liters of blood flow per minute at a resting heart rate of 70 beats per minute. The pump of this example is formed with housing interior  18  of inside diameter 6.75 cm, center ball  115  of diameter 3.15 cm, an input shaft  32  of diameter 1.0 cm, secondary vane integral hinge portion  86  outside diameter of 3.75 cm and thickness of 0.5 cm in the vicinity of and axial direction of stub shaft  74 , primary vane semicircular hinge portion  66  thickness of 0.675 cm in the radial direction of stub shaft  74 , oblique angle of 45 degrees between longitudinal axis of the carrier ring shaft  104  with respect to the axis of fixed shaft  40 , angle  321  of 44 degrees that the cross-sectional points nearest center ball  115  that the primary vanes  56 ,  58  and secondary vanes  76 ,  78  make with center of ball  115 , and face angle  322  of 7 degrees that the vane faces make with respect to line  323  which intersects the center of ball  115  and the corner of the cross-section of primary vane nearest center ball  115 . With this combination the pulsatile spherical pump of the instant invention can supply the required five liters/minute flow using input shaft rotational speeds of approximately 35 rpm, which rotational speed would also provide approximately 70 pulsatile “beats” per minute. This can be compared to rotational speeds of 4000-8000 for some current heart pumps.  
         [0123]     For this embodiment, the materials of construction for the pump are selected from those known to have a high degree of hemocompatibility and biocompatibility in living systems, such materials including but not limited to titanium, pyrolytic carbon, Dacron, heparin, polyvinyl pyrrolidone- and polyacrylamide-based polymers, polyurethanes, and phosphorylcholines. In addition to these basic materials of construction some coatings can be applied to blood contacting surfaces or materials that can be added to the blood flowing through the system to increase the hemocompatibility of the blood-biomaterial interface. The materials so used include heparin, heparin proteoglycans, polyethylene-glycol-diisocyanate, saratin, clopidogrel (Plavix), triazolopyrimadine, prostaglandins, prostacyclin, prostaglandin E1, acenocoumarol (Sintrom; Novartis Pharma, Vienna, Austria), acetylsalicylic acid (aspirin) and derivatives of any of the foregoing.  
         [0124]     For the case of this embodiment with internal implantation, the pump is implanted into the chest or abdominal cavity of the recipient and anchored in place by attachment via fasteners or tethers to the bones, muscles, sinews, and/or internal organs of the recipient. The surfaces of the pump may be either smooth or optionally porous to provide ingrowth of host cells to further anchor to and provide hemocompatibility and/or biocompatibility within the body. For a case where pump  10  is used as a biventricular assist device (biVAD), two each of ports  24 ,  26  of pump  10  are provided two inlet connections and two outlet connections for a total of four connections, which in turn are connected to the left and/or right ventricle, left and/or right atrium, aorta, pulmonary artery and/or another systemic or pulmonary artery or vein as best suited for the needs of the individual&#39;s case, and based upon whether the device is being used as a partial assist or total replacement for one or both ventricles of the heart. As a total replacement for both ventricles the four chambers of pump  10  provide unique equivalence in many ways to the four chambers of the heart. The flow rate of the device of this embodiment may be controlled by any combination of control of rotation rate of primary vane  52  or by means of flow control  124 . For the latter in the case of internal implantation, the flow control  124  is preferably modified to a smaller profile from that shown in  FIG. 1 . An example of the smaller profile  120 A is shown for example in  FIGS. 9, 11 , and  13 . For the case where an electrical motor turns input shaft  32 , the motor may either be attached locally to pump  10 , or the motor may optionally be located remotely from pump  10 , and connected to input shaft  32  via a rotary coupling or cable. Such remote operation may be desirable when there are space constraints, (e.g., in a small child) or to relocate the heat that may be generated by the motor remotely from pump  10 .  
         [0125]     As an alternative to the use of an external motor, the movement of vanes  52  and/or  54  can be powered electromagnetically. In this aspect, vanes  52  and/or  54  have, for example, permanent magnets imbedded in or on them in a way that does not interfere with the biocompatibility or hemocompatibility of pump  10 . The vanes modified in this way are then moved via, for example, an electromagnetic field that is applied from within or external to the housing. This field is then sequenced in progressive locations in such a way as to maintain motion of vanes  52 ,  54  and therefore the pumping action of pump  10 . In this aspect, input shaft  32  may be passive rather than a transferring member of the motive power, and may penetrate only the interior wall of housing  12  and end prior to penetrating the exterior surface of housing  12 . Such a configuration may be advantageous in terms of compactness, which is desirable from the standpoint of implantation, as well as advantageous in reduction of the number of moving parts and simplification of manufacture, both of which are desirable in terms of reliability and cost. As another variation of this aspect with the carrier ring mounted external to spherical interior  18  in a manner similar to that described above for  FIGS. 15-16 , the carrier ring can be used as a stator to effect movement of secondary vane  54 , which due to the previously described coupling to primary vane  52  via first and second pivotal axes both rotates the primary vane  52  and secondary vane  54  and causes the pivotal oscillation of secondary vane  52  with respect to primary vane  54 , and pumping action with respect to inlet ports  24 ,  26  and discharge ports  24 ,  26  as described previously. With proper placement of said embedded magnets in vanes  52 ,  54  and appropriately configured magnetic fields from within or from outside of housing  12 , rotation of primary vane  52  can be effected about primary axis  33 , without the need for input shaft  32  to penetrate the interior wall of housing  12 , and without the need for a carrier ring within spherical interior  18  or a carrier ring external to spherical interior  18 . With this combination of proper placement of magnets and configuration of magnetic fields, the rotation of primary vane  52  about rotational axis  33  is stably maintained by said combination, and the pivotal oscillation of secondary vane  54  relative to primary vane  52  is also stably maintained by said combination. This has the dual advantages of reducing friction and reducing surface interfaces that may otherwise tend to difficulties in avoiding thrombosis.  
         [0126]     The pulsatile blood pumping system can also be configured in a mode wherein the motor for rotating the first shaft is physically detached from the housing of the pump but either mechanically or electromagnetically linked to the first shaft. In this aspect of the invention the detached motor could be implanted in an abdominal cavity while the pumping system is implanted in the chest cavity of a living organism. Alternately the power required to rotate the first shaft can be supplied from outside the body (transcutaneously) by techniques such as radio frequency power transmitted across a receiving coil or via magnets coupled across a recipient&#39;s skin surface or through the skin (percutaneously) via an electrical line, mechanical cable or pneumatic tubing.  
         [0127]     For the case of this embodiment with external use, the pump is located external to the recipient and mounted on a suitable carrier that is preferably mobile. Blood fluid is circulated with the inventive device to and from the recipient. The surfaces of the pump are preferably temperature controlled. Pump  10  can be configured as a biVAD in a manner similar to that described above for an implanted device, or can be configured to assist or replace one or both ventricles. The motor may either be attached locally to pump  10 , or the motor may optionally be located remotely from pump  10 , and connected to input shaft  32  via a rotary coupling or cable and/or a magnetic coupling. Such remote operation may be desirable to isolate heat generated by the motor away from the pump. Alternatively, thermal isolation may be accomplished using insulating material between the motor and pump. Also, in this case, ports can be relatively conveniently modified using changeable inserts as described for  FIG. 24  below.  
         [0128]     For the case of this embodiment where the vanes  56 ,  58 ,  76 ,  78  are similar in dimensions,  FIG. 31  depicts the variation of the volume (in mL) of fluid chambers  301  (curve  444 ), and  302  (curve  888 ) as primary vane  52  is rotated about the axis of input shaft  32 . As previously explained herein, however, alterations can independently provide differences in flow rates through one or more of the fluid chambers. Returning to the specific case depicted in  FIG. 31 , the volumes of the chambers  301 ,  302  vary sinusoidally with a maximum volume of 36.2 ml as the primary vane  52  is rotated one full revolution (2×π radians) about the axis of input shaft  32  at a rate of 35 rpm. In this embodiment, the output flow of chambers  301 ,  303  have coincident peaks and troughs and are provided with a first common outlet, and the output flow of chambers  302 ,  304  have coincident peaks and troughs and are provided with a second common outlet. Such combined output and input flows may be useful, for example in the case where pump  10  is being used as a left ventricular assist device (LVAD) or as a right ventricular assist device (RVAD). Separating the two inlet flows and two outlet flows would of necessity provide a different transient flow profile, while not detracting from their pulsatile nature. Since the volume variations have offset timings as depicted by distance  390  in  FIG. 31 , the flow rates also vary with offset timings, and the depicted embodiment provides two flow pulses of 72.4 ml, one each from the first and second common outlets, with each revolution of the primary vane  52  about the input shaft  32 , giving an average flow rate of about 5 liters per minute, and approximating a heart beat rate of 70 pulses or “beats” per minute, which matches the normal requirements of the example recipient above. Both flow rate and pulsation rate can be increased to the maximum anticipated need of the recipient by increasing the rate of rotation of input shaft  32 . In the preferred embodiment for the case of the pump being used to assist or replace both ventricles, the output from the four chambers is separated and the ratio of magnitudes of flow through the first and second outlets is adjusted as described in the paragraphs below to better reflect the natural difference between the flow of the right and left ventricles of the heart, which is typically about 20% higher in the left ventricle. In this preferred embodiment for assisting or replacing both ventricles, the present invention can provide the distinction of providing two substantially simultaneous pulse peaks (discharge surges) from the same device, which is highly advantageous from a physiological standpoint. Additionally, the device provides two substantially simultaneous pulse troughs (intake surges), which is also highly advantageous. Furthermore, the device provides at least one pair of simultaneous intake and discharge streams. In an optional embodiment when this device is used as a heart assist device or ventricular assist device, electronic sensors and control circuitry is used to time the pump rotation so that flow pulsations delivered by pump  10  coincide, with or without peak-to-peak offset, flow pulsations of one or both of the heart ventricles of the recipient. Still further, the shape of a transient flow curve corresponding to any chamber of pump  10  may be modified by appropriately placing a flow element with capacitive (e.g., elastic properties) and/or resistive characteristics in communication with said chamber. It is apparent without further explanation, that this embodiment providing a pump capable for being used as an artificial heart or heart assist device may also include any combination of features of the above- and below-mentioned embodiments to reduce shear stresses on the blood being pumped through the machine, vary the ratio of flow rates between chambers, flush components and/or provide tight tolerances between moving parts.  
         [0129]     A significant advantage of this embodiment of the present invention is that it does not require valves in the traditional sense. Valves of prior art artificial hearts are prone to wearing out and to becoming calcified, which are both disadvantageous for a life-sustaining device. Another advantage of the present invention is that it can be sized to match both the normal flow rate and provide the pulsatile flow that mimic the natural characteristics of the recipient&#39;s heart. Another advantage is that the present invention can be operated at relatively low rpm, simplifying motor requirements and reducing the potential for wear of moving parts. Still another advantage is the relatively small size of the pump.  
         [0130]     For use as a blood pump the pulsatile blood pumping systems with internal carrier rings described as part of the instant invention can have alternate designs with respect to the internal sphere. One design is to have is no contact between the vanes and both the internal sphere and the housing of the machine. With no internal contact between those internal components the pulsatile blood pumping system just described has the potential for long life during use. In constant use however instabilities can occur that result in vibration of the internal structures, causing for example unwanted interference between the exterior surfaces of vanes  52 ,  54  and the interior of housing  12  and/or the exterior surfaces of spherical portion  102  and the end cap  108 . Accordingly a second design provides for improved rigidity of the internal structure of the pump.  FIG. 17  shows this second design that significantly improves the rigidity of the internal structure of the pump. At the interior end of rotating shaft  32  a nipple  133  is extended into the end cap  108  and rotatably attached by means of a suitable bearing assembly (not shown). This extended nipple provides significantly improved rigidity to the design without significantly increasing the load on the rotating shaft. The extended nipple also allows the inclusion of a pathway for a lubricating coolant fluid or a flushing fluid to and through the central ball  115 . Alternately the desired rigidity can be supplied by an extension  135  from the central ball  115  attached rotatably to input shaft  32  as shown in  FIG. 18 . It should be recognized that the rigidity desired from this change could also be achieved by related mechanical implementations, such as a sleeve extending from the central ball  115  and encircling the input shaft  32  with appropriate bearing assembly to maintain the shaft as rotatable, or such as a rotatable coupling between the primary vane  50 A and end cap  108 . These latter two versions of the rigidity solution are not shown in the drawings.  
         [0131]     In another embodiment to inhibit fluid leakage between chambers seals are provided between the two vanes and the central ball and seals are also provided between the two vanes and the pump housing. Also to inhibit fluid leakage and with reference to  FIG. 3  and  FIG. 4 , preferably seals are provided (but not shown) between the stub shaft  74  and the recesses  94 ; likewise seals are provided (but not shown) between the stub shaft  96  and the recesses  72 , between the outer side edges  73  of primary vane halves  56 ,  58  and inner side edges  89  of secondary vane halves  76 ,  78 , and between narrow ridges  83  of the secondary vane halves  76 ,  78  and the hinge portions  66 ,  68  of primary vane halves  56 ,  58 . It should be recognized that such seals could be made from high performance plastic or elastomeric materials. Alternatively, the seals of this embodiment may be brush seals or labyrinth seals, both of which are commonly known.  
         [0132]     The use of the prior art machine as described earlier was limited in that it did not provide for balancing forces upon the secondary vane as it neared the relatively closed position with respect to the primary vane. As shown in  FIG. 19 , secondary vane  98 B is approaching the relatively closed position with respect to primary vane  50 B. The pressure of the fluid being pressurized in chamber  301  exerts a force depicted in the general direction  101 , which pressure force was not balanced in prior art machines by the force depicted in the general direction  103  which latter force is due to the slowing of momentum of secondary vane  98 B. In an embodiment of the present invention, the weight or density of secondary vane  98 B is adjusted to balance momentum force  103  with pressure force  101 , which lowers the wear on the interfacing surfaces and bearings between secondary vanes  98 A,  98 B and the carrier ring  116 , and between the carrier ring  116  and the carrier ring shaft  104 . This adjustment of weight or density may be accomplished by any combination of the following means: selection of materials of differing densities or composite combination of materials which combination achieves differing densities, and/or void spaces in the vanes.  
         [0133]     The pulsatile spherical blood pumping system can be configured to flow two different fluids, such as for example oxygen-rich blood and oxygen-poor blood through the same pump as can pump one fluid.  FIGS. 20A-20E  show sequenced views of the pump  10  in operation with the control lever  120  in the 0 degree position as the input shaft  32  is rotated through 180 degrees of revolution and while simultaneously flowing two fluids through its interior. In this configuration, the single pump  10  acts as two pumps simultaneously, and therefore is able to do the work of two pumps while occupying much less space than two pumps. For conceptual convenience, the majority of the lower housing half  14  is not shown. As discussed with  FIGS. 10A-10E , motion of the input shaft  32  causes each secondary vane  98 A,  98 B to reciprocate or move back and forth between a fully open position and a fully closed position with respect to primary vanes  50 A,  50 B. Chamber  301  is defined as the space between primary vane  50 B and secondary vane  98 B, chamber  302  is defined as the space between primary vane  50 B and secondary vane  98 A, chamber  303  is defined as the space between primary vane  50 A and secondary vane  98 A and chamber  304  is defined as the space between primary vane  50 A and secondary vane  98 B.  
         [0134]     In the depicted embodiment, simultaneous flow of two fluids is accomplished by connecting upper port  24  to a first fluid source and lower port  26  to a second fluid source. Lower port  24  acts as an outlet for the first fluid and upper port  26  acts as an outlet for the second fluid.  FIG. 20F  shows that concept by showing the port openings only. First fluid  196  enters upper port opening  24  and exits lower port opening  24 . Second fluid  196  enters lower port opening  26  and exits upper port opening  26 . In the sequences shown in  FIGS. 20A-20E , the first fluid flows from the first fluid source through upper port  24  into chamber  301 , and from chamber  302  out of lower port  24 . Simultaneously, the second fluid flows from the second fluid source through lower port  26  into chamber  303 , and from chamber  304  out of upper port  26 . This separation of flows of the two fluids is facilitated by the previously discussed seals between the vanes and the interior of the housing  12 , between the vanes and the exterior of the central ball  115 , and between the primary vanes  50 A,  50 B and secondary vanes  98 A,  98 B.  
         [0135]     In similar manner as described for  FIGS. 20A-20E , as the input shaft  32  is rotated through another 180 degrees of rotation, first fluid flows from the first fluid source through upper port  24  into chamber  302 , and from chamber  301  out of lower port  24 . Simultaneously, the second fluid flows from the second fluid source through lower port  26  into chamber  304 , and from chamber  303  out of upper port  26 . In the depicted embodiment, chambers  301  and  302  transfer only the first fluid through upper and lower ports  24 , and chambers  303  and  304  transfer only the second fluid through upper and lower ports  26 .  
         [0136]     As an example of an embodiment that is particularly useful, as an alternative to using a motor to drive pump  10 , motive power for rotating input shaft  32  of pump  10  may be provided by flowing a first fluid under pressure from a first fluid source in the above configuration through upper port  24 , which alternatingly powers the expansion of chambers  301  and  302  which in turn rotates primary vane  50  about input shaft  32 . Chambers  303  and  304  then draw in and expel blood fluid from and to the recipient. Advantages of this embodiment include reduced space and elimination of heat that would otherwise be generated by an electric drive motor. This first fluid is preferably a biocompatible liquid, but may also include inert and/or humidified gas.  
         [0137]     The ability to separately control the flow of two different blood fluid streams in the same pulsatile blood pumping systems is an important concept of the instant invention. In another embodiment of the instant invention,  FIGS. 23A-23E  show sequenced views of the pump  10  in operation with the control lever  120  in the 0 degree position as the input shaft  32  is rotated through 180 degrees of revolution and while simultaneously flowing two fluid streams at two different flow rates through its interior. For conceptual convenience, the majority of the lower housing half is not shown. As discussed with  FIGS. 20A-20E , motion of the input shaft  32  causes each secondary vane  98 A,  98 B to reciprocate or move back and forth between a fully open position and a fully closed position with respect to primary vanes  50 A,  50 B, varying the volumes of chambers  301 - 304  as previously defined. Simultaneous flow of multiple fluid streams at different flow rates is accomplished by rotating ports  26  about the axis of input shaft  32  in relationship to ports  24 . In the depicted embodiment, ports  26  are rotated 20 degrees about the axis of input shaft  32 . Upper port  24  is connected to a first fluid source and lower port  26  to a second fluid source. Lower port  24  acts as an outlet for the first fluid and upper port  26  acts as an outlet for the second fluid. In this embodiment, the first and second fluid may be either the same fluid or different fluids. In the sequences shown in  FIGS. 23A-23E , the net flow rate of second fluid from the second fluid source through lower port  26  has been decreased, due to the altering of the position of ports  26  with respect to the opening and closing of the secondary vanes  98 A,  98 B with respect to primary vanes  50 A,  50 B, in a manner similar to that previously described when second shaft assembly  100  is rotated to various fixed positions as described for the sequences in  FIGS. 10A-10E ,  12 A- 12 E,  14 A- 14 E.  
         [0138]     In this embodiment, rotating the position of ports  26  about the axis of the input shaft  32  in relationship to ports  24  may be accomplished through several means. One such means would be to provide eccentric port inserts  27 A as shown in  FIG. 24 . Both upper and lower ports  26  are rotated in this manner to a similar extent, to avoid fluid locking of the pump. The shapes provided for the openings of port inserts  27 A could obviously be selected from a great variety (e.g., oblong) to effect various alterations of flow through said port openings. This insert means may also be alternatively employed with the carrier ring on the outside of the housing interior, as taught by Stecklein in U.S. Pat. No. 5,199,864. As shown in  FIG. 25 , another such means is to divide housing halves  14 ,  16  into quarter sections  14 A,  14 B,  16 A,  16 B along the plane perpendicular to the axis of input shaft  32  and intersecting the center of center ball  115 . Flanges are provided to each quarter section to allow sealing of quarter sections  14 A,  16 A to quarter sections  14 B,  16 B after rotation of ports  24  to a new fixed position (for example, by rotating quarter sections  14 B,  16 B about the axis of input shaft  32 ). Additional means of rotating ports  24  about the axis of input shaft  32  relative to ports  26  may also be employed, as readily apparent to those skilled in the art. This embodiment may be implemented independent of or in combination with any number of the above-mentioned embodiments that provide for flow of multiple fluids, that provide for removal of heat from the interior of the pump, that provide for changeable ports, or that provide for stabilization of the structure.  
         [0139]     Additional embodiments that independently vary the relative flow rates through at least two ports are possible. These include altering the shape or one or more face angles of any of the vanes  50 A,  50 B,  98 A,  98 B, which shape altering may optionally be accomplished by plates driven by hydraulic bladders, providing corresponding adjustments to the flow of fluid(s) through chambers  301 - 304 . Another embodiment includes providing a path for relative one-way flow between chambers. The flow path may be through or around a vane, and is tapered or valved to preferentially allow flow in one direction.  
         [0140]     Traditional centrifugal or axial flow pumps used in blood pumping applications are moving blood fluids vigorously through the pump during the entire cycle of pumping. In the pump described and claimed in the instant invention blood fluids are drawn into one of the fluid chambers through an intake port and held temporarily until the fluid chamber approaches a discharge port where the blood fluid is discharged as the chamber closes. In this manner the pulsatile blood pumping system described more closely resembles the action of a human heart, which brings in blood and temporarily holds it before discharging.  
         [0141]     Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Many such variations and modifications may be considered obvious and desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.