JP2000510929A - Hybrid centrifugal pumping apparatus and method suspended and rotated by magnetic force - Google Patents

Abstract

(57) Summary (i) Integrated impellers and rotors (21), which are entirely magnetically supported and rotated by electromagnets (52, 54), (ii) Pumps for fluid flow and enclosure Housing and arcuate passages (32, 34, 36); (iii) a brushless drive motor (40) embedded and integrated in the pump housing; (iv) a power supply; (v) unique electronic sensing and control. Algorithms for centrifugal pumps (10) for pumping sensitive biological fluids, including algorithms, all of which are tightly combined to provide efficient, long-lasting, low maintenance operation. Apparatus and method. A specially designed impeller and pump housing provide a mechanism for transporting and delivering fluid through the fluid pump to the pump output port with low fluid turbulence.

Description

DETAILED DESCRIPTION OF THE INVENTION Hybrid centrifugal pumping apparatus and method suspended and rotated by magnetic force Background of the Invention Field of the invention The present invention relates to a rotor supported and rotated by magnetic force, more specifically, a disk-shaped impeller is suspended and rotated by magnetic force in a non-contact state, and the rotation speed of the impeller is controlled by a fluid pressure and an impeller positioning algorithm. Centrifugal pumping apparatus and method that is controlled and varied in a controlled manner. 2. Background art Historically, fluid pumps are of many and varied types and forms, all of which serve essentially the same end purpose, i.e., move fluid from one point to another. Fulfills the function of causing All pumps have similar features in that the negative pressure created by the operation of the pump draws fluid into the pump through a container or tube. In addition to the main negative pressure, secondary forces such as gravity, impeller inertia, or existing pipe / vessel fluid pressure also affect the fluid flow. Activating the pumping mechanism creates fluid pressure and / or fluid velocity, which then creates a negative pressure that draws fluid through the inlet port of the pump into the pump. Fluid from the inlet port is conveyed across the pump by a pump mechanism, which then directs the fluid to the pump outlet port. The configuration of the fluid pump mainly depends on the adaptation to the function. For example, suction pumps and push-up pumps use reciprocating motion to move fluid, while vacuum pumps generate a negative pressure used to move fluid. Rotating axial pumps utilize a propeller-like blade mounted on a rotating shaft to achieve fluid transfer. Jet pumps utilize jet flow ejectors. The jet flow ejector enters a narrow chamber within the pump to create a low pressure region that correspondingly generates a suction that draws fluid from the inlet port into the chamber. Other types of pumps can also be identified, but the following is for fluid pumps for sensitive fluids such as blood, where the dimensions and geometry of the pump are more easily adaptable to critical environments. This will be described with particular reference. Rotary centrifugal pumps are inherently more rigid and easily adaptable to pump sensitive fluids. Blood flow pumps have relatively low flow performance characteristics compared to many conventional industrial uses, but require significant pressure build-up. Centrifugal pumps are better suited for such applications than axial pumps or other designs. This results in the use of a centrifugal pump design for the preferred embodiment of the present invention. The pump has a number of ribs or vanes attached to the impeller, and the rotational force of the vanes drives the fluid out of the rotor by centrifugal force. Centrifugal pumps conventionally include an impeller mounted on a shaft immersed in a fluid, where the shaft extends through a seal and bearing device to a drive mechanism. The rotating blades of the impeller create a partial negative pressure near the center of the axis of rotation, which correspondingly draws fluid through the blow opening of the pump. A smooth pump volute is located within the stationary components of the pump to ensure a smooth flow of the pumped fluid from the impeller outlet to the pump outlet passage. The volute serves to build up the flow of the pump from the pump impeller and increase the fluid pressure (head) by converting the kinetic energy (velocity) of the fluid into potential energy (pressure or head pressure). Centrifugal pumps do not require a valve to move the fluid, but the fluid aspirated through the inlet opening continues to flow in the pump mechanism, and without internal fluid leakage or loss of efficiency. The pump geometry must be such that it continues to flow to the outlet port. These prior art pumps are known to have problems. For example, shaft seals configured in conventional centrifugal pumps have the disadvantage that they are subject to wear, fatigue, and are more susceptible to shock by certain fluids, resulting in leakage problems. It is described in. It is also well known that pumps for certain fluids require more careful design considerations and require unique pumping techniques to avoid fluid damage, contamination and other undesirable conditions. . For example, fluids such as corrosive fluids (acids or caustic) or sensitive fluids such as blood require special considerations to prevent the seal from leaking and thereby losing fluid integrity. And The pumping of sensitive fluids, such as blood, by a steady-flow pump requires extremely reliable and non-damaging bearings to support the rotating impeller. Prior art pumps have very significant problems with the bearings required to support the impeller as it rotates. Ball bearings and other rolling element bearings can be employed only if they are isolated from sensitive fluids (blood) by a shaft seal and are lubricated other than body fluids. In this situation, all the sealing problems mentioned above apply. If a conventional ball bearing or other rolling element bearing employs a sensitive fluid as the lubricating fluid, the sensitive fluid, such as red blood cells in the blood, will be crushed between the rolling components in the bearing, and so Biological features are destroyed in a short time. Some prior art pumps employ thrust and radial fluid film bearings lubricated by sensitive fluids. These bearings may fail, form thrombi (clots), and form sensitive fluids due to clotting action (high shear forces) due to poor performance and / or rotating components sticking to stationary components. Causes damage and other problems. Also, fluid film bearings do not provide any information about the instantaneous pump pressure and flow that can be employed to control the speed of the motor to meet the physiological needs for future pump performance. Conventional ball bearings and fluid film thrust bearings and radial bearings require the long-term reliability required in pumps, such as blood pumps, which must avoid fluid static and fluid high shear stresses. I do not have. Further, when ball bearings are employed for pumping sensitive fluids, they have a short life and often must be lubricated by an external lubricating fluid, which is used to hold the lubricating fluid. Need a seal. Transporting and retaining the lubricating fluid for the bearings increases the overall size of the pump housing and increases the complexity of operation due to the use of extra vessels and mechanisms for lubricating fluid supply and cooling. Therefore, when used to replace the original heart function, the pump device cannot be implanted. Because of this, the relatively short life of a fluid pump having a shaft and conventional bearings renders the pump unsuitable for implantation in a body cavity for an extended period of time to replace its natural heart function. . In addition, pumping of blood involves certain known risks typically associated with shaft seals for impeller-type blood pumps because the fluid cavity is susceptible to stagnation and excessive heat. In addition, pumping sensitive fluids such as blood requires careful consideration of the impeller blade and pump housing geometry. Excessive physical action and heating of the blood will destroy blood components by coagulation and protein denaturation, which will cause blood to clot and clot. Avoiding the damaging effects of pumping blood is best achieved by intrinsic heart function. The natural heart has two basic functions, each side of which performs a different pumping function. The right side of the natural heart receives blood from the body and pumps it to the lungs, while the left side of the natural heart collects blood from the lungs and pumps the blood to the body. The natural heart beat, in combination with a heart valve, provides a pumping action of blood in a beating, extremely smooth and flowing manner. The natural heart blood flow (cardiac output) is otherwise regulated primarily by venous return flow, known as pump preload. However, some or all of the original heart function may be lost due to illness or accident. Mechanical devices that have been developed to replace the original heart function have historically functioned in the size range from the earliest cardiopulmonary or pump oxygen generators to more recent devices. The dimensions and function of modern devices are more closely analogous to those of the natural heart. In addition to whole heart replacement, the development of other mechanical devices will replace some of the functions of the original heart, such as ventricular assist devices that support the left ventricle weakened by illness or other damage. The emphasis is on The primary consideration for replacing the function of the heart, whether part or all of the heart, is to gently, non-heated and non-destructively circulate the blood throughout the device. It must be pumped at For example, if a pump impeller supported by a mechanical bearing comes into contact with blood, the relative movement of the parts of the bearing will result in excessive mechanical action of the blood, which may cause blood cells to divide. Will cause blood clots. Another mechanical effect that can damage blood is that it forms a region where blood substantially stagnates or does not exchange enough blood, causing blood to swirl, and thus To create a state corresponding to the stagnation. The blood often clots as a result of the stagnant blood (thrombus), and correspondingly the blood does not flow at all. Another effect that can damage the blood is that it overheats as the blood flows through the pump due to the frictional forces of the side walls of the pump or other pumping mechanism. Specifically, the frictional forces on the side walls due to the sharp change in the internal geometry of the pump require that the blood flow change direction significantly, which means that the blood cells , I.e., activate the platelets of the blood, causing a corresponding clotting and thrombus. Another effect that can damage the blood is due to the inefficient operation of the pump, whereby most of the energy supplied to the pump device is pumped into the blood, Appears as heat that damages the blood due to overheating and clotting. Importantly, the inefficiency of the pump operation, which overheats the blood as the albumin of the blood begins to denature at 42 ° C., can be very serious and life-threatening. The stagnation described above, the rapid geometry of the pump, turbulence and / or heating can damage the red blood cell cells that activate blood platelets and / or carry oxygen. When blood is damaged, it causes a chain reaction that forms blood clots that can clog blood vessels, causing the tissues that are nourished by those blood vessels to become undernourished, causing serious, life-threatening conditions. Become. Many attempts to circumvent the above problems associated with pumping blood have been made by using flexible diaphragms and compressible tubing in roller pumps. However, the constant flexing of the diaphragm and / or tubing material alters the nature of the material in contact with the blood, causing the material to fatigue, causing the inner wall of flexible material to fall off, and It is known that emboli will be pushed into the vascular stream. In addition to the above requirements for pumping blood, the rotational speed of the impeller has a significant effect on the stability and structure of sensitive blood vessels. Rotation of the impeller, which is not regulated by the preload pressure of the pump, creates an atrial suction in the sensitive blood vessel just before the inlet port of the pump, and when the rotation speed of the impeller exceeds the strength of the vessel wall, Blood vessels collapse. Prior art pumping devices do not integrate the controller to a sufficient degree to ensure that rapid adjustment to the rotational speed of the impeller does not have an undesirable effect. Kletschka '005 (U.S. Pat. No. 5,055,005) discloses a fluid pump suspended by an opposing fluid. Just stabilizing the impeller with the opposing fluid is not enough to keep the impeller in the correct position in the pump housing, and the high pressure fluid jet causes the blood to dislodge the aforementioned blood due to the mechanical action of the blood. Solidification will occur. Klechakka '877 (U.S. Pat. No. 5,195,877) includes a magnetically suspended impeller utilizing a rigidly mounted shaft surrounded by a magnetically suspended rotor that acts as an impeller for the fluid. A fluid pump comprising: The shaft of the present invention requires the use of hydraulic bearings and seals at the connection between the shaft and the rotating impeller, which allows blood or other sensitive fluids to become heated and stagnant in the bearing area. Flow conditions will occur. For over 25 years, those skilled in the art have provided pumps for use as completed artificial hearts and have experimentally implanted them in animals. These studies provide useful feedback information on the relative effectiveness of the blood pump. These pumps can be categorized as types that produce pulsatile or non-pulsatile flow. A pump (constant volume) that produces pulsatile fluid motion is more exactly analogous to the fluid motion provided by the natural heart. Whether pulsatile fluid movement is necessary to obtain the required physiological benefit, or whether the pulsatile fluid movement is primarily due to the non-rotating nature of the myocardium Is not disclosed in information to date. Most pulsatile pumps commonly require valves (mechanical or tissue) with inherent mechanical problems and limitations. While no valve arrangement is required in prior art non-pulsating pumps, non-pulsating pumps require a rotating shaft through various bearings and seals. These shafts create a problem with the nature of blood stagnation, contamination and undesirable heating conditions, which makes the use of the pump prolonged to replace the function of the heart proper. Make it unfeasible. Most early prior art rotary non-pulsatile devices have been installed outside the body to assist the heart for a short period of time and have had limited success. One blood pumping device is a completed artificial heart. This completed artificial heart has also been used in five patients as a permanent replacement for a physiologically incurable ventricle and as a temporary bridge for heart transplantation in 300 patients. I have. The longest period supported by a completed artificial heart is 795 days. For example, other blood pumping devices, such as ventricular assist devices, have been used for patients who cannot stay away from cardiopulmonary bypass during cardiac surgery, or for patients whose only ventricle has failed. I have. The most common mechanical replacement of intrinsic heart function is to use the ventricular assist device as a temporary tie for heart transplantation, and this temporary ventricular assist device applies to more than 1250 patients. Have been. Historically, blood pumps have a number of problems. For example, the pumping mechanism (diaphragm) of a completed reciprocating artificial heart is operated by gas (pneumatic device), fluid (hydraulic device), electricity (motor, solenoid, etc.) and skeletal muscle. The energy source and the associated transport device comprise additional components that increase the overall complexity of the device and thus make it unreliable as a whole. Also, the size of the prior art device relative to the completed prosthesis is very limited with respect to patient movement and does not improve the patient's quality of life. Another limiting factor that has not been completely solved by prior art devices is the oversize and complexity of the energy conversion device and the overall design of the pump is greater than the available body part space. is there. In addition, most of these prior art reciprocating devices have an abnormally large (i) noise characteristic, (ii) vibration, and (iii) reaction force (thrust force). Many of the problems of the prior art rotary pumps are solved by those skilled in the art by adapting the pump to provide the ability to pump sensitive fluids (such as blood) to meet the above requirements. ing. The application of these pumps can be realized by supporting the impeller through an electromagnet disposed on the impeller and the housing such that the impeller can rotate without a shaft seal or a lubricating device. Some types of permanent magnets that do not use an additional support cannot completely suspend one object, such as an impeller, and have additional adjustments in some axes to achieve stable suspension. Requires possible support or force. This is based on Earnshaw's theory showing that suspensions consisting solely of permanent magnets are not stable. However, actively controlled electromagnets can be used to stabilize and support the object for all degrees of freedom of movement. Accordingly, the electromagnet can stably suspend an object (that is, an impeller in the case of a centrifugal fluid pump) by the calculated positioning. The only energy dissipated in a magnetically supported impeller is the electromagnetic energy used to stabilize and rotate the impeller. The electromagnet for suspending and rotating the impeller produces a stable and efficient operation of the pump. Prior art patents within the last decade have disclosed magnetically suspended and rotating rotors with only limited success. These prior art forms utilize partial magnetic suspension to reduce the risk to blood. While magnetically suspended prior art devices successfully mitigate some of the risks of rotary shaft friction, prior art devices still have size, complexity and sub-optimal impeller positioning, position detection and speed. In terms of control, it is not practical to implant for whole heart replacement. The over-dimensions of these prior art inventions, and the difficulty in maintaining the exact position and speed of the impeller, are largely due to the impeller geometry of cylindrical, spherical, or other mostly three-dimensional nature. It is. In view of the above, an improved centrifugal pumping device that is suspended and rotated by magnetic force can be improved, thereby reducing the size of the impeller, increasing the accuracy of positioning the impeller, and improving the speed control. Then would be a significant advance in the art. It also provides a centrifugal pumping device that is free of shafts, rolling elements or fluid film bearings, mechanical seals or physical proximity sensors, thereby providing mechanical contact, wear, failure due to fluid bearing sticking, thrombus. Or, a completely integrated pump design that would not cause shear damage would be an advance in the art. A centrifugal pump with an impeller and pump housing geometry to efficiently and low turbulently transport fluid throughout a pump mechanism, including an output port of the pump. If obtained, it would be a further advance in the art. Further, it would be an advance in the art to provide a multifunctional centrifugal pumping device that operates in either a pulsating or non-pulsating mode. OBJECTS AND SUMMARY OF THE INVENTION The main object of the present invention is to improve a rotary centrifugal fluid pump for sensitive fluids. It is another object of the present invention to improve a fluid pump using an efficient non-contact electromagnetic bearing and an efficient motor. It is an object of the present invention to provide a centrifugal pump of relatively compact dimensions that allows it to be implanted in a body part. It is yet another object of the present invention to provide a centrifugal pumping apparatus and method that has a long product life and requires minimal maintenance. Yet another object of the present invention is to improve centrifugal fluid pumps used to replace partial or total cardiac function. It is a further object of the present invention to provide efficient and low turbulence, including low turbulence output slightly beyond the outlet port throughout the pump due to the geometry of the pump design. It is an object of the present invention to provide a centrifugal pumping device and method that enables transport of a state and provides a sensitive fluid output. It is yet another object of the present invention to provide a centrifugal pumping apparatus and method wherein the fluid pressure and output fluid volume are controlled and electronically changed via a specific fluid pressure and positioning algorithm. . It is yet another object of the present invention to provide a centrifugal pumping apparatus and method operable in either a pulsating or non-pulsating mode. It is yet another object of the present invention to provide a centrifugal pumping device and method applicable as either a ventricular assist device or a twin device for total heart replacement. The above objectives, and other objectives not specifically set forth, are achieved by a centrifugal fluid pump apparatus and method for pumping a sharp biological fluid. The apparatus comprises: (i) an integral impeller and rotor fully supported by an integral electromagnetic bearing and rotated by an integral motor; and (ii) an arcuate passage for flowing and retaining the pump housing and fluid. (Iii) a brushless drive motor embedded and integral with the pump housing; (iv) a power supply; and (v) motor speed and pump performance based on input from electromagnetic bearing current and motor back emf. Electronically detecting the position, velocity or acceleration of the impeller using self-sensing methods and physiological control algorithms. All of these are securely connected together so that efficient, long life, low maintenance pump operation can be achieved. Specially designed impellers and pump housings provide a mechanism for transporting and supplying fluid with low turbulence from the pump to the pump outlet port. The above and other objects and features of the present invention will be readily apparent from the following description of preferred and other embodiments of the present invention, along with the accompanying drawings and claims. Would. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will become apparent from a review of the following detailed description, taken in conjunction with the accompanying drawings. In the accompanying drawings, FIG. 1 is a perspective view of a pumping device of the present invention supported and rotated by magnetic force. FIG. 2 is an exploded side view of a pumping device completely supported by one electromagnetic bearing and rotated by the electric motor of the present invention. FIG. 3 is a cross-sectional view of FIG. 1 along line 3-3. FIG. 4A is a plan view of FIG. 3 along line A. FIG. 4B is a cross-sectional view of FIG. FIG. 5A is a plan view of FIG. 3 along line B. FIG. 5B is a cross-sectional view of FIG. FIG. 6A is a plan view of the preferred embodiment of FIG. FIG. 6B is a cross-sectional view taken along line C of FIG. FIG. 7A is a plan view along the line D in FIG. FIG. 7B is a sectional view taken along line D in FIG. FIG. 8 is an enlarged partial sectional view of the pump impeller and the housing of FIG. FIG. 9 is a perspective view of the pump impeller of the present invention shown in semi-transparent mode for clarity. FIG. 10 is a cross-sectional view of the pump impeller along the line AA in FIG. FIG. 11 is a front view of the pump impeller along line BB of FIG. 9 with the shroud assembly removed. FIG. 12A is a partial cross-sectional view of a magnetic component of a magnetically suspended impeller of a pump according to the present invention. FIG. 12B is a cross-sectional view of both the magnetic components of the pump and the magnetically suspended impeller according to the present invention, showing the cross-sectional dimensions of the pump. FIG. 12D is a partial cross-sectional view of a magnetically suspended impeller of the pump described in the present invention. FIG. 13 is a diagram showing a coordinate system and symbols indicating six electromagnetic operation directions for the pump of the present invention. FIG. 14 is a plan view of a circular row of eight horseshoe magnets used to form a thrust / moment bearing shape on the face of the impeller. FIG. 15A is a plan view of a circular row of four horseshoe magnets used to form a radial / thrust bearing configuration on a pump stator. FIG. 15B is a cross-sectional view of a circular row of four horseshoe magnets used to form the radial / thrust bearing shape of the pump. FIG. 16A is an electronic circuit diagram that provides electronic feedback to control the position of the impeller within the clearance region of the stator. FIG. 16B is a diagram illustrating further details of the electronic circuit of FIG. 16B that provides electronic feedback for controlling the position of the impeller within the stator clearance region. FIG. 17 shows a filter that captures fluid gap dimension information while removing the effects of power supply voltage, switch frequency, duty cycle changes, and electronic or magnetic noise, from the self-sensing portion of the present invention. FIG. 3 is a diagram showing an electronic filter of FIG. FIG. 18 is a table of a graph of a signal when the signal passes through the filter of FIG. FIG. 19 is a schematic diagram of an integrator circuit controlled by an analog multiplier whose gain is an indicator of the evaluated gap. FIG. 20 is a schematic diagram of a physiological electronic feedback control circuit based on motor current and speed. FIG. 21 is a schematic diagram of a physiological electronic feedback control circuit based on bearing current. FIG. 22 is a diagram of a physiological electronic feedback control circuit that controls motor speed in response to pre-load and post-load signals. DETAILED DESCRIPTION Reference will now be made to the drawings, in which case elements of the present invention will be designated by certain reference numbers, and the present invention will be deemed to enable those skilled in the art to make and use the invention. explain. It is to be understood that the following description is only illustrative of the principles of the present invention, and should not be construed as limiting the scope of the claims. Overall description The background objectives for rotary centrifugal pumps with impellers fully supported by a combination of permanent magnets and electromagnetic bearings and rotated by an electric motor are: (1) excessive heat, (2) stagnant flow, (3) blood clotting. (Thrombus), or (4) high shear forces on fluid or blood components (coagulation) due to fluid instability caused by turbulence or mechanical action of the fluid due to sudden pumping mechanisms or geometries. ) To prevent blood or other sensitive fluids from being damaged. Further, the dimensions of the device of the present invention can be mounted within the available body part space when used to support a natural whole heart replacement or ventricle. To be suitable as a blood pump, the pump must be sufficiently adaptable to the physiological return needs of a ventricular or biventricular assist device for total heart replacement. As a whole heart replacement device, the pump must be small in size and mass small enough to be implanted in the space of the available body part, and some inconvenience may occur in the surrounding organs due to excessive device weight. It must not be profitable. Moreover, the disk shape of the impeller of the present invention significantly reduces the size and complexity of the pumping device. The pumping device of the present invention can be used alone as a ventricular assist device that supports the function of the heart or replaces a portion of the function of the heart, or forms a mechanical whole heart replacement by combining a pair of devices. can do. In a total heart replacement, the combined dimensions of the two devices are approximately equal to the dimensions of the original heart, which allows it to be implanted in the space of an existing body part. The impeller of the present invention is completely suspended and wrapped within its pump housing so that it operates in a non-contact manner between the pump impeller and any other part of the pump. The pump impeller is suspended in an electromagnetic bearing. An electric motor rotates the pump impeller, performs the pumping function of the fluid, and provides for adjusting the positioning of the impeller with respect to the pump housing. The apparent absence of shafts, ball bearings, shaft seals or other sources of contamination significantly increases the product life of the pumping device of the present invention, thereby providing a long-term natural heart replacement. enable. Although the pump impeller rotates about an axis, the term "axial" is used herein to indicate a direction parallel to the axis of rotation of the pump impeller. In this specification, the term "radial" is used to indicate a direction perpendicular to the axial direction. The present invention consists of electromagnetic bearings made of magnetic and other materials, which are actuated by current in a coil wound around the magnetic components of the bearing. This current produces both axial and radial forces. A plurality of appropriately configured magnetic bearings disposed around the impeller are required to center the impeller during pump operation and prevent contact between rotating and stationary components. . You have to control the impeller's six degrees of freedom, three translations and three rotations. Operating in this non-contact state allows the bearing to operate without loss due to wear or friction. The position and rotational speed of the impeller of the present invention is controlled by a specific algorithm that detects and responds to the fluid pressure and the six axial positions of the pump impeller in the pump housing. To adjust the rotational speed and / or the position of the impeller to provide a fully integrated physiological control controller. The rotational speed of the impeller corresponds to the pressure of the fluid at the preload pressure (inlet pressure) and / or the outlet pressure of the pump and is adjusted to meet the need for bodily fluids to increase or decrease the pump flow or increase the pressure. . The geometric design of the pumping system of the present invention moves fluid in a smooth, non-turbulent and non-heated state throughout the pump mechanism. The rotation of the impeller causes the fluid to move by centrifugal force by means of a special curved impeller blade. The blades of the curved impeller extend from the center of the disk-shaped impeller and extend toward the outside of the impeller, and at the same time, generate a partial negative pressure in a region near the rotation axis of the impeller. This partial vacuum draws additional fluid into the inlet port. Blood or other sensitive fluid will not stagnate anywhere in the pumping device as the return fluid will flow along the side of the impeller, and the side of the impeller will have a stagnant cavity, The fluid returns to the center of the impeller without flow interruption by bearings or seals. Importantly, the pump housing, impeller vanes, outlet ports and all other features of the pumping device of the present invention are due to stagnant flow, excessive heat, turbulence, and excessive mechanical action of the fluid. To protect sensitive fluids from damage. Fluid is transported throughout the pumping device at steep angles without a change in direction of flow. The configuration of the pump housing is designed with a helical volute curve, so that the same curvature gradient throughout the pump housing means that the direction angle can change any sharply and the corresponding thermal friction And allows fluid to be transported within the pump housing without increasing energy and losing energy due to friction with the side walls of the pump. Another important feature of the pumping device of the present invention is that it can operate in either a pulsating or non-pulsating mode. The pump operates in a pulsatile mode by periodically changing the rotation speed of the impeller, which more accurately resembles the original heart pumping action, while the uniform rotation speed of the impeller causes Operate in non-pulsatile mode. Changing the operating mode from pulsatile to non-pulsatile or vice versa is accomplished through changing the operating settings of the pump, thereby changing from either pulsatile or non-pulsatile. Avoids the trauma associated with replacing the entire pumping device when it is determined that this is the preferred mode of operation. Preferred embodiment Referring to FIG. 1, a magnetically suspended and rotated centrifugal pump device according to the present invention is shown generally as a structure 10. The structure 10 is formed by a first pump housing half 12 and a second pump housing half 14 and forms an area for an enclosure of other pump components, which will be described in detail below. A hermetic seal 28 is provided. The electronic controller required for operation and the battery or other power source for operation are not shown. The structure 10 is provided with one or more pump inlet vessels as shown in FIG. 1 and comprises one inlet vessel 19 as a preferred embodiment. The pump inlet vessel 19 includes an inlet through hole 20 formed seamlessly and integrally with the first pump housing half 12 and providing an enclosure for the fluid entering the pump structure 10. In. Fluid enters the pump structure 10 via a pump inlet container 19 which provides an enclosure and supply for the fluid by the inlet inflow through hole 20 and reaches a region proximate the central axis of the pump structure 10. . An outlet container 15 is disposed tangentially from the outer diameter of the structure 10, the outlet container being formed by the combination of the first pump housing half 12 and the second pump housing half 14. And an enclosing wall provided with a pump outlet through hole 16 and sealed by a hermetic seal 28. FIG. 2 is an exploded side view of the magnetically supported and rotated pump device of the present invention. This exploded view shows the pump inlet 19, the first pump half 12, the bearing plate 100, the impeller shroud 104, the impeller hub 108, the impeller inlet 112, the impeller vanes 116, the rotor 120 of the motor, the outlet vessel 15 and the pump outlet through hole. 16 is shown. FIG. 2 also shows a combined axial and axial thrust bearing housing 124 and a combined radial and axial thrust bearing housing 126. Referring to FIG. 3, a spiral volute outlet 18 is formed by the combination of the first pump housing half 12 and the second pump housing half 14 and is sealed by a hermetic seal 28. Importantly, the shape of the logarithmically changing spiral volute outlet 18 of the present invention utilizes the curvilinear form of the spiral volute and the sudden and violent direction during travel from the impeller to the outlet vessel 15. To avoid damaging the sensing fluid as described above. The combination of the first pump housing half 12 and the second pump housing half 14 together with the hermetic seal 28 provides an enclosure for the inner impeller 21 and the impeller chambers 27A, 27B, 27D and 27d, which will be described in detail below. (See FIG. 9). Fluid flows all around the impeller 21 via the first return flow chamber 32 and the second return flow chamber 34. FIG. 4A is a plan view of part A of FIG. Part A is a part of the housing half 14 of the second pump (or structure) 10. FIG. 4B shows a cross section of the second pump housing half 14 part A. The winding 54 in this configuration is clearly visible and allows for the fabrication of this part of the pump 10. 4A and 4B, conical pole faces 51 are also shown. 5A and 5B similarly show a portion of the pump 10, but FIG. 5A is a plan view of portion B (see FIG. 3) of the first pump housing half 12, and FIG. It is sectional drawing of the part B of No. 3. Again, windings (ie, control coils) 52 and bias coils 53 are shown to enable one skilled in the art to make the pump 10. FIG. 6A also shows part C of FIG. 3 in plan view to show stator 80 of motor 40. FIG. 6B shows section C in cross-section to show winding 84. Motor 40 is described in further detail below. FIG. 7A shows part D of FIG. 3 in plan view to show the rotor or impeller 21 of the motor 40 and to show the arrangement of the permanent magnets 92 on the rotor. The magnets 92 are alternately arranged correctly like the north pole 91, the south pole 93, the north pole 91, and the south pole 93 until the circular arrangement shown in FIG. 7A is completed. FIG. 7B shows section D in cross section to show rotor 21. The rotor 21 will be described in more detail below. FIG. 8 is an enlarged cutaway sectional view of the pump impeller and the housing of FIG. FIG. 8 focuses on a portion of the cross-sectional view shown in FIG. 3 and may be referenced during the above description of FIG. 3 to provide more clarity to the disclosure made with respect to FIG. it can. The pump impeller 21 includes two or more impeller blades 26a, 26b, 26c, 26d shown in FIG. 9, and in a preferred embodiment four impeller blades 26a, 26b, 26c, 26d and 26a, 26b, 26c, 26db. And 26a, 26b, 26c, 26dc and 26a, 26b, 26c, 26dd. Each of the impeller blades 26a, 26b, 26c, 26d is mounted between the impeller enclosure plate 22 and the impeller hub 24 so that the impeller chambers 27a, 27b, 27c, 27d are formed. Each of the impeller blades 26a, 26b, 26c, 26d and 26a, 26b, 26c, 26db and 26a, 26b, 26c, 26dc and 26a, 26b, 26c, 26dd is respectively connected to the impeller chambers 27a, 27b, 27c, 27d. Yes, it is. Referring to FIGS. 9, 10 and 11, the impeller blades 26a, 26b, 26c, 26d are formed by spiral curves, and the rotation of the impeller 21 causes the impeller blades 26a, 26b, 26c, 26d to be pressure-fed. The fluid is brought into contact with the fluid so that the fluid moves radially toward the helical volute outlet 18 (see FIG. 3). The centrifugal rotation of the impeller 21 causes fluid to be carried from the region of the central axis of the structure 10 toward the helical volute outlet 18 and correspondingly the region of the impeller inlet opening 30. , A partial vacuum is created and further fluid is drawn through the inflow vessel 19 (FIG. 1). In particular, as shown in FIG. 11, the impeller is designed to allow a smooth transition of the flow vector from the inlet to the outlet. This is achieved in one particular embodiment employing a blade angle of 17 ° at the base of the blade at inlet A. The blade angle gradually decreases to an angle of 11 ° at the top of the blade at inlet B. Thus, the blade is not axially straight near the inlet. The blade is gradually transitioning near its midpoint D at an angle of 37 ° until it is axially straight. This 37 ° angle is maintained up to exit point D. All blade angles are angles inside the blade relative to a tangent to a circle centered on the center of the impeller. Referring to FIG. 2, to provide a smooth flow of fluid pumped from the impeller outlet at a relatively high speed to the pump outlet passage where the fluid is slowed down before exiting the pump. The pump volute is located within the fixed part of the pump. Volutes increase fluid pressure (head pressure) by converting the kinetic energy (velocity) of the fluid into potential energy (pressure or head pressure). In one particular embodiment, the clearance around impeller 21 is maintained at 0.030 inches to allow for good cleaning of the surface. Any change in the direction of flow in the clearance passage is made by maximizing the radius of curvature to maintain laminar flow. Referring again to FIGS. 3 and 8, in one embodiment, a portion of the fluid pumped by the impeller 21 is removed from the high pressure region near the spiral volute 18 along both sides of the impeller 21 by a first pressure. It returns as a backflow through the impeller return chamber 32 and the second impeller return chamber 34 to a low pressure region near the impeller inlet opening 30. Fluid returning along the second impeller return chamber 34 also passes through the impeller return opening 36, thereby serving to equalize the internal pressure. The width of the return chambers 32 and 34 of the impeller balances the initial fluid flow and the countercurrent flow accurately so that the fluid does not stay in the pump and has unnecessary inefficiencies. Is calculated by: The pump impeller 21 is suspended within the pump housing by electromagnetic bearing sets 52,54. The preferred embodiment of the electromagnetic bearing set controls the combination of the axial thrust and angular moment of the impeller 21 with the axial position and angular displacement of the impeller 21, while the electromagnetic bearing set 54 In cooperation with the set 52, the axial thrust of the impeller 21 controls the combination of the axial position and the radial force and position. The impeller 21 is completely electromagnetically suspended and rotated by an electric motor to provide contactless operation, which increases the overall product life and reliability and damages sensitive fluids as described above. Avoid. The set of electromagnetic bearings 52, 54 are designed to resist axial and radial forces and moments imparted by fluid motor forces, the effects of impeller gyroscope dynamics, gravitational loads, acceleration forces and other attendant forces. Provides the required axial, radial and moment controlled forces. 6A and 6B are a plan view and a cross-sectional view of the stator 80 of the motor 40, as described above. Motor 40 is a three-phase brushless motor and provides electromagnetic force to start and rotate pump impeller or rotor 21. As shown in FIGS. 7A and 7B, the motor 40 consists of a permanent magnet rotor 21 with a permanent magnet 92 embedded in the hub of a centrifugal or mixed flow pump. The magnets 92 are arranged in a wedge shape so as to form a circular rotor. The magnets 92 are arranged so that the magnetization of the permanent magnet alternates between the north pole and the south pole along the periphery of the rotor 21. Referring to FIGS. 6A and 6B, the motor stator 80 has a winding 84 that is energized by current from an electronic controller. The magnetic field interacts with the permanent magnet 92 to generate a torque in the rotor 21. Although the motor stator 80 can be suspended in at least three shapes depending on torque, speed and bearing requirements, the shapes of FIGS. 6A and 6B show a shape that does not include iron parts for the motor stator. Thus, the stator 80 has no saturable magnetic material, thus minimizing the thrust force created by the motor. As shown in FIG. 6A, wire 84 is wound on a separate securing member and secured in place on rotor 80 using epoxy or a similar material. The above configuration meets the specific critical conditions for a flow pump for a medical device for the required centrifugation or mixing, as explained in the background. By using permanent magnets in the rotor, there is no mechanical contact between the rotor and the stator of the motor. The set of electromagnetic bearings 52, 54 allows the rotor / impeller 21 to rotate without any contact with the stator 80. The geometry of the motor meets the requirements of allowing the motor to drive the pump in an efficient manner while providing laminar flow within the flow gap with minimal stagnation of blood. This is achieved by keeping the radius of curvature large. 12A, 12B, 12C show the layout of one embodiment of a magnetically suspended impeller. Each figure shows a different part of the same embodiment. FIG. 12A shows only the magnetic components of the pump. The electromagnets 52 and 54 are mounted on a stator (a component that does not rotate), and the magnetic plate 92 is disposed on an impeller (a component that rotates). Only the impeller 21 surrounded by the pump housing or stator is shown to emphasize the flow paths 32, 34, 36. There is no clear shaft, and the impeller is directly supported and driven by a motor, thereby reducing the length and complexity of the impeller recirculation path and making the device extremely compact. FIG. 12B is a more detailed cross-sectional view of the pump. To facilitate understanding of the size of the pump, the lines 120, 121 of the graph are shown. In one embodiment, the line 120 of the graph is approximately 3 inches long. The line 121 of the graph is sized in proportion to the line 120 of the graph. Although other lengths are possible for the lines 120 and 121 of the graph, the present invention will typically be in a patient's thorax with a pump device incorporated inside the chest to assist in heart function. It is sized to fit. If the pump is used for other applications, it may be sized differently than the preferred embodiment. FIG. 13 shows a coordinate system for defining the magnetic operation of the impeller 21 in the necessary six directions, ie, three translation directions (x, y, z) and three rotation directions (φ, ψ, θ). ing. All three translational displacements (x, y, z) and two rotational directions (pitching about two axes) (φ, ψ) are held in space relative to the stator by magnetic forces. It has been almost fixed. The final rotation (θ) about the z-axis is achieved by the motor. In a preferred embodiment, the magnetic bearing is formed in two parts: 1) a thrust / moment configuration and 2) a radial / thrust configuration. First, as shown in FIG. 14, the thrust / moment bearing shape is a circular array of eight horseshoe electromagnets oriented on the impeller inlet face. In this embodiment, although many structures are used to form a four quadrant actuator, eight coils are used with the actuation coil and there are four control quadrants. It is wound in pairs. This provides a combination of axial actuation (z) and pitching moment (φ, ψ). The thrust force (z) is generated by applying equal coil currents to all coils such that each pole in the electromagnetic bearing applies the same force on the bearing plate. The angular pitching actuation force (moment) is also measured by opposing coils for actuation above and below the center line of the impeller (φ angular displacement) and actuation of the impeller to the left and right (ψ angular displacement). To different coil currents. The function of the electronic controller is to determine what combination of currents must be employed to control these axes. Second, like FIGS. 4A and 5A, FIG. 15A is a plan view of a radial / thrust and thrust / moment bearing shape. The radial / thrust bearing includes four horseshoe shapes, including eight pole faces 301-308. The eight pole faces of the thrust / moment bearing are shown at 309-316. FIG. 15B is a side view of the impeller 21 showing the plate 208 being a radial / thrust bearing plate with a beveled magnetic surface (shown in detail in FIG. 7B at 208). FIG. 15B also shows another plate 100 that is a thrust / moment bearing plate. This magnetic bearing shape can provide controlled forces in axial (z), radial (x, y) and angular displacement (φ, ψ). These two magnetic bearing shapes, thrust / moment shapes and radial / thrust shapes, create the necessary electromagnetic forces and moments needed to hold the impeller in a centered position and keep it under control 8. Provides two independent electromagnetic coil currents. The horseshoe-like operation of the electromagnet in this embodiment is simplified and increased by employing a bias current. This bias current is employed in all coils, but may be different for each bearing shape. The bias current is enabled by the control coil current where the bearing is linear near the static bias current. This bias current also provides a near kinematic force generation capability in the form of a magnetic bearing. In this application, a large bias current will result in high heat generation. This high exotherm is undesirable for use in human sensitive fluids such as blood. Therefore, a low bias current is used to reduce heat generation. In the present invention, an electronic controller is provided for automatically adjusting the working bearing coil current in the set of electromagnetic bearings 52 and 54, the working bearing coil current then being provided with the applied forces and moments. , The control force and the moment exerted on the rotary impeller 21 by the magnetic bearing are adjusted. Such an electronic controller, during operation, has a continuous electronic signal relating to the position or velocity or acceleration or a combination of position, velocity and acceleration of the rotating impeller in the clearance space provided inside the frame of the pump. Supplied. The present invention also provides the switching or DC power amplifier and power supply required to operate the electromagnetic actuator in the magnetic bearing. 16A and 16B show an embodiment of an electronic circuit for electronic feedback control of the position of the impeller within the clearance region of the stator. Electronic circuits formed by resistors, capacitors, amplifiers, etc. use proportional-integral-differential control methods or nonlinear control algorithms such as state space, mu synthesis, linear parameter variation control and sliding mode control. And combined to control the kinematics of the impeller. Gyroscope of rigid body of impeller Special control algorithm to take into account inertial properties where mechanical force, fluid stiffness, damping and size depend on impeller position, rotation speed, pressure rise and flow velocity Is used. In one embodiment, the physical circuit is miniaturized using surface mount technology, very large scale integrated circuit (VLSI) design, and other means. In the embodiment shown, the control algorithm forms eight coil currents that control three displacements (x, y, z) and two angular displacements (φ, ψ). The controller algorithm design is robust to take into account the uncertainties in the forces acting on the impeller, such as fluid stiffness, damping and inertia, gyroscope dynamics, magnetic forces, and the like. The control algorithm can perform an implementation of adjustable parameter variables to take into account different physical needs for different uses for humans of different sizes, from children to large adults. Given for a dedicated microprocessor. In the present invention, a power amplifier is employed to generate the desired coil current for the electromagnetic bearing as determined by the control output voltage. One embodiment of a switching amplifier that operates with a voltage that is turned on or off at a frequency much higher than the rotational frequency of the pump impeller, because power amplifiers with efficiencies in the range of 85-95% are very efficient. Are used in this device. The electronic power circuit comprises a magnetic coil with resistance and inductance, a resistor, a capacitor, and semiconductor components. The coil is made using a wire having a low resistance. These power circuits are designed to be regenerative. That is, the power-enabled magnetic bearing moves back and forth between the magnetic coil inductors to the capacitor, and the only loss is caused only by the low coil resistance (ohmic loss). The high power present in the magnetic coil circuit is only a small part of the nominal power supply capacity, which is defined as the switching average current in the coil multiplied by the supply voltage. With these low power switching amplifiers and regenerative coil power circuits, unwanted heating of the blood is kept at a minimum. The present invention is designed to generate an electronic signal related to the position, speed or acceleration of the rotating impeller via one of the following: One of: (i) a physical element such as eddy current, induction, optical, capacitance or other approach; or (ii) a combination of current and voltage provided to a working coil within a magnetic bearing. It is designed to generate an electronic signal through one. In the case of a physical sensor located on the frame of the pump near the clearance gap between the frame and the rotating impeller, the electronic position, speed or acceleration signal is the signal conditioning electronics and electronic signals for the magnetic bearing. It is obtained from wiring provided for inputting signals into the controller. In the case of a self-sensing signal, signal conditioning is provided to determine the position, speed or acceleration of the rotating impeller without any physical elements, thereby providing a signal path in the wiring path between the electromagnetic actuator and the electronic controller. The required number of wires is reduced to a minimum. A preferred embodiment of the sensing function of the present invention is a self-sensing feature. The self-sensing configuration avoids the use of physical sensors in the stator, minimizes the size of the pump, and minimizes the number of wires required for operation. In one embodiment shown in FIGS. 16A and 16B, position sensing is a voltage and current switching waveform for some of the electromagnetic coils (as employed by the switching power amplifier described above). Is achieved by examining Each coil is driven by a switching power amplifier with a high carrier frequency (of the order of kHz). The resulting current waveform (one embodiment is shown in FIG. 18) has a relatively low frequency commanded waveform (to generate the control force needed to position the impeller) and This is a combination with a high-frequency triangular waveform by high-frequency carrier. The amplitude (magnitude) of the commanded waveform is determined by the inductance of the circuit (inductance of the magnetic material characteristics of the magnetic bearing and the inductance due to the fluid gap), the switching frequency, and the duty ratio of the switching amplifier (the desired control force). (The ratio of the on-voltage to the off-voltage employed in the amplifier to generate). FIG. 17 is provided in the self-sensing portion of the present invention to retrieve fluid gap size information while eliminating the effects of power supply voltage, switching frequency, duty cycle changes and electronic or magnetic noise. 1 shows an embodiment of an electronic filter. Parameter estimation methods have been employed to demodulate the signal and determine the size of the fluid gap. One embodiment of a filter enclosure is employed, which includes a high-pass filter to remove bias currents, a precision rectifier to make the waveform exactly positive, and removes residual signal fluctuations. A low-pass filter. The embodiment shown in FIG. 17 provides a high-bandwidth low-noise sensor suitable for determining the size of the fluid gap by a self-detection signal. FIG. 18 shows a series of signal configurations as they pass through the filter, the graph showing the supply coil voltage at 180, the typical actual coil current waveform at 182, and 184. 19 shows a current signal output from an integrator (shown in detail in FIG. 19) for removing a change in coil current due to control of an externally applied force and moment, and 186 shows a rectification mode of 184. 188 showing the 186 time averages retrieved using the low pass electronic filter at 188. FIG. 19 shows a circuit for extracting a change in coil current due to control of an externally applied force and moment. This is shown in the preferred embodiment of a negative feedback circuit that includes an integrator controlled by an analog multiplier whose gain is indicative of the estimated gap. The feedback circuit includes a proportional integrator, in which the estimated displacement and the integral of the estimated displacement are combined to form a negative feedback signal, and then the original voltage Compared to the waveform, it provides a desired current waveform that is proportional to the impeller displacement. The use of pumps for sensitive applications often requires regulation of flow rates and pressure rises, such as artificial hearts, where physiological conditions change significantly. For example, a human body may require a higher flow rate and pressure increase when performing a movement such as walking, but may require a lower flow rate and pressure increase when the body is at rest or sleeping. unknown. In the present invention, the main way to adjust the flow rate and pressure rise is by changing the motor speed. In physiologic applications, the pump inlet pressure is referred to as preload and the pump outlet pressure is referred to as afterload. A second embodiment of the physiologic controller provides a pressure rise (ie, P P) from the pump inlet to the pump outlet. _out −P _in ) Uses indirect measurements. At a given flow rate, a change in pressure across the pump is an indication of a change in system resistance in the patient's circulatory system. Changes in system resistance are known as one indicator of high human physical activity. Therefore, the measurement of the pressure difference from the outlet to the inlet is used as a reference for the physiological controller. The measurement of the pressure difference from the inlet to the outlet should be indirectly measured by two methods: (1) measuring the current of the motor and the speed of the pump, or (2) measuring the bearing current or some combination of these. Can be. In physiological applications, the pressure at the pump inlet is called preload, while the pressure at the pump outlet is called afterload. The first way to measure pressure is to use the measurement of motor current and pump speed indirectly. These measurements are used in an electronic controller to derive pressure based on equations and / or tables electronically stored in the controller. The relationship between current, speed and pressure rise is characterized and calibrated before actuation to provide a reference for the controller. A block diagram for the execution of the controller is shown in FIG. A second method for measuring pressure rise uses magnetic bearing currents indirectly. It is well known that the current in an active magnetic bearing is directly proportional to the force acting on the rotor. The pressure difference between the outlet and the inlet of the pump can be directly derived from the sum of the forces acting on the impeller by the pressure difference. Thus, the bearing current can be used in an electronic controller to derive a pressure differential from the outlet to the inlet of the pump. A block diagram of the execution of this controller is shown in FIG. FIG. 22 shows another embodiment of the physiological electronic feedback control circuit, which in the present invention adjusts the motor speed for the preload and afterload signals to properly control the motor speed. It is provided in. Physiological control circuits are provided for adjusting the pump flow rate and pressure rise to meet biological requirements. Reference numeral 220 indicates the interface between the physiological controller and the commutator of the motor such that the desired speed signal is sent to the commutator of the motor and the actual speed signal is sent to the physiological controller. Thus, the embodiment shown in FIG. 22 illustrates motor control based on physiological parameters. In addition to the electronic signals relating to the pre-load and post-load forces applied to the interior of the pump, the electronic signals from the actuation coil currents in the electromagnetic bearings are used to control the load due to gravity and the acceleration effects associated with starting and stopping operation. Related to other forces. Also, the electronic signal relating to the acceleration is obtained by sensing the acceleration in one, two or three orthogonal directions at a location known to the pump in the pump housing or elsewhere. This acceleration electronic signal is then employed in the present invention to subtract that signal from the pre-load and post-load signals described above. The resulting difference signal is then used for the physiological controller described above. Motor speed is related to the physiological performance of the pump. The motor feedback emf (electromotive force) is used to detect the rotation speed of the motor rotating about the pump impeller shaft and to generate an electronic signal proportional to the rotation speed of the impeller. This impeller rotational speed signal is provided to the electronic physiological feedback controller described above. The rotational speed of the motor is combined with the pre-load and post-load signals described above to regulate future motor speeds and to meet the need for pressure increases based on physiological pump flow rates and human body requirements. used. Method The components of the structure 10 can operate in a single mode as a ventricular assist device or in pairs for the entire artificial heart. In the case of a completed artificial heart using two structures 10, each of the structures 10 functions completely independent of the other structure, thereby eliminating complex controllers and eliminating both structures. It eliminates the circuitry required when the bodies are combined. A physiologic controller (not shown) senses the fluid pressure inside the uptake vessel 19 and an electrical signal for modifying the rotational speed of the motor 40 according to a particular algorithm determined by an electronic controller (not shown). Occurs. The physiologic controller can signal a change in the rotational speed of the motor 40 to compensate for changes in fluid pressure inside the uptake container 19 while avoiding excessive motor rotational speeds that could collapse the container. . In addition to controlling the rotational speed of the motor 40, a physiological controller (not shown) may control the position, speed and / or acceleration of the impeller 21 via eddy currents, induction, optical, capacitance or other self-sensing electronic signals. Detect information and generate electrical signals. This electrical signal is sent to an electronic controller (not shown) and correspondingly provides an adjustment to the current in the electromagnetic bearing set 52, 54, thereby providing an adjustment to the control force. Adjustments to the set of electromagnetic bearings 52, 54 compensate for the forces exerted by the fluid, motor forces, gravitational loads, acceleration forces and other attendant forces. Rotation of the impeller 21 places the impeller blades 26a, 26b, 26c, 26d in contact with the fluid being pumped, thereby moving the fluid toward the spiral volute outlet 18. In response to the centrifugal movement of the fluid from the region at the axis center of the structure 10 towards the outlet of the helical volute, a partial vacuum is formed in the region of the impeller intake opening 30 via the intake container 19. One additional fluid phrase is included. This unique logarithmic helical shape of the helical volute outlet 18 then allows the sensitive fluid to flow in a smooth, undisturbed, cooler form and along the area near the outer periphery of the structure 10 to the outlet vessel 15. Carry up to. The outlet vessel 15 is connected to an anatomical vessel or other mechanism. A portion of the fluid pumped by the impeller 21 is reversed from the high pressure region near the helical volute 18 along both sides of the impeller 21 via the first impeller return chamber 32 and the second impeller return chamber 34. Back in the form of directional fluid flow to a low pressure region near the impeller intake opening 30. The fluid returning along the second impeller return chamber 34 also passes through the return opening 36 of the impeller, thereby serving to equalize the internal fluid pressure and cause the flow in the clearance passage to cause a stagnation of sensitive fluid. To prevent When the structure 10 is operated in the pulsating mode, the rotational speed of the impeller 21 is changed and controlled by an electronic controller (not shown) that regulates the current in the motor 40, thereby controlling the impeller 21. The rotation is accelerated or decelerated, and the fluid is pumped in a pulsating form. The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The embodiments described above are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes included in the meaning and equivalent scope of each claim are to be included in the scope of these claims.

────────────────────────────────────────────────── ─── Continuation of front page    (81) Designated countries EP (AT, BE, CH, DE, DK, ES, FI, FR, GB, GR, IE, IT, L U, MC, NL, PT, SE), OA (BF, BJ, CF) , CG, CI, CM, GA, GN, ML, MR, NE, SN, TD, TG), AP (GH, KE, LS, MW, S D, SZ, UG), EA (AM, AZ, BY, KG, KZ , MD, RU, TJ, TM), AL, AM, AT, AU , AZ, BA, BB, BG, BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, G B, GE, GH, HU, IL, IS, JP, KE, KG , KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, N O, NZ, PL, PT, RO, RU, SD, SE, SG , SI, SK, TJ, TM, TR, TT, UA, UG, UZ, VN, YU (72) Inventors Bernson and Jill Brent             Salt Re, 84106, Utah, United States             Ike City, East Jasper             Vehicle 982 (72) Olsen, Don Bee             Salt Re, 84121, Utah, United States             Ike City, Blue Jay Lane             8832 (72) Inventor Maslen, Eric H             22903 Virginia, United States             -Reeseville, Rias Ford Law             De 748 (72) Inventor Long, James W.             Salt Re, 84124, Utah, United States             Ike City, South Parkview             Live 4461

Claims (1)

[Claims]   1. An apparatus for pumping a sensitive biological fluid, comprising:   A structure having an outside, a hollow inside having a wall inside, and an axis center;   A fluid is formed from the outside of the structure, through which fluid passes through the interior of the structure. An entrance for passing to the side,   A fluid is formed from the outside of the structure, and fluid is passed from inside the hollow of the structure Through which are arranged radially from the axial center of the structure. Exit and   Entering through the entrance, disposed inside the structure without contacting the structure. B) to control the flow of fluid through the hollow interior of the structure and out of said outlet; Impeller means having an arcuate blade and an arcuate passage, whereby Fluid flow through the structure is gradually directed from the inlet to the outlet Impeller means,   Suspending the impeller means without contacting the hollow interior of the structure Magnetic means for   The impeller means is selectively rotated, whereby the flow of fluid through the device is increased. Motor means for controlling the   Equipment including.   5. The apparatus according to claim 1, wherein   An impeller for fluid flow through the structure; Controlled by motor means whereby said motor means is said impeller means And a rotor that enables the rotation of the rotor to be controlled. Thus, the inside of each of the first return flow chamber and the second return flow chamber Integrated to form and allow fluid flow around the suspended impeller means Device, including a combination.   6. The apparatus according to claim 5, wherein   The interior of the impeller forming the first return flow chamber has the structure An apparatus comprising a first member having a curvature corresponding to a curvature of a hollow inner wall of a body.   7. The device according to claim 6, wherein   A first electromagnetic magnetic material for the impeller to interact with a first set of electromagnetic bearings Including fees,   The first set of electromagnetic bearings stabilizes the impeller means and provides The axial position of the step and the external thrust forces and motors acting on the impeller means Control measures, measures.   8. The device according to claim 6, wherein   A first electromagnetic magnetic material for the impeller to interact with a first set of electromagnetic bearings Including fees,   The first set of electromagnetic bearings stabilizes the impeller means and provides The axial position of the step, angular displacement in two degrees of freedom, and outward thrust force And a combination of an external moment acting on the impeller means, Measure.   9. The apparatus according to claim 5, wherein   The inside of the rotor forming the second return flow chamber is of the structure A second member having a curvature corresponding to the curvature of the hollow inner wall; Is connected to the first member by the arcuate blade of the impeller means, The chamber of the propeller comprises (i) an arcuate blade, (ii) a first member, and (iii) a second part. And the fluid from the inlet to the outlet is gradually directed again. A device forming an arcuate passageway through which to pass.   10. An apparatus according to claim 9, wherein   A second member for interacting with a second set of electromagnetic thrust bearings; Containing a magnetic material of   The second set of electromagnetic bearings has two degrees of freedom in radial position and the impeller hand. A device that controls the outer radial force acting on a step.   11. An apparatus according to claim 9, wherein   A second member for interacting with a second set of electromagnetic thrust bearings; Containing a magnetic material of   The second set of electromagnetic bearings has two degrees of freedom in radial position, axial position, A combination of an outer radial force and an outer thrust force acting on said impeller means; A device that controls mating.   12. An apparatus according to claim 10, wherein   The second magnetic material is such that the second set of electromagnetic bearings has two radial positions. Degrees of freedom, axial position, angular position, outer radial force, Combination of the last direction force and the outer moment acting on the impeller means To control the device.   13. An apparatus according to claim 9, wherein   The second member includes a rotor integrally formed therein; The motor has a plurality of permanent magnets arranged to interact with the motor means. And the rotor is rotated by the motor means, whereby A device for rotating impeller means.   14． The apparatus according to claim 1, wherein   The magnetic means,   A first set of electromagnetic bearings provided on a hollow inner wall of said structure;   A second set of electromagnetic bearings provided on another wall inside the hollow of the structure;   A magnet provided on the impeller means and corresponding to the first set of electromagnetic bearings; A first bar of material;   A magnet provided on the impeller means and corresponding to the second set of electromagnetic bearings; A second bar of material;   The structure provides control over five degrees of freedom of the impeller means,   The impeller means comprises: (i) a set of the first electromagnetic bearing and the first magnetic material (Ii) the second set of electromagnetic bearings and the second magnetic material Magnetic field between the bars prevents contact with the hollow interior of the structure Equipment made to be done.   15. An apparatus according to claim 14, wherein   The magnetic means for controlling current in the first and second sets of electromagnetic bearings; An apparatus, including an electronic controller.   16. The apparatus according to claim 15, wherein   The electronic controller controls the rotation speed of the impeller to control the device of the present invention. Physiological use to make the rotation speed correspond to human physiological condition An apparatus, including a controller.   17． An apparatus according to claim 14, wherein   The structure is such that the set of electromagnetic bearings controls two degrees of freedom of the impeller. Positioned at an angle from the first magnetic material so that it can be used for An apparatus comprising said first set of electromagnetic bearings.   22. A continuous flow pump for pumping a sensitive biological fluid, comprising:   A structure, comprising a first pump housing half and a first pump housing A second pump housing hermetically sealed to the halves to form the same structure And a structure having a hollow inside and an axis center,   The first pump housing half is formed from which fluid passes therethrough. Pump having an inlet through-hole for a passage for passing into the hollow interior of the structure An inlet container,   The first and second housings are arranged radially from the center of the axis of the structure, and Formed from the halves, through which the fluid passes from inside the hollow of the structure A pump outlet container having an outlet through hole for a passage for   With impeller means arranged inside the hollow of the structure without contacting the same structure The impeller intake opening, the impeller chamber, and the impeller chamber Impeller vanes having a helical curve to form the pump inlet Fluid flow into the vessel, fluid flow through the hollow interior of the cavity and Impeller means for controlling the flow of fluid from the pump outlet vessel,   The impeller means is suspended without contact with the hollow interior of the structure and Selectively rotating the impeller means, thereby passing through the continuous flow pump. Magnetic means for controlling the flow of the fluid,   Motor means for controlling the rotation speed of the impeller means,   Including a continuous flow pump.   22. A method for pumping a sensitive biological fluid using a pump, comprising:   A pump device having a magnetically suspended impeller in a pump housing. Thus, the impeller reduces the impact on sensitive fluid moving in the pump. Select a pump device with a bow-shaped blade for   The impeller received from magnetic means being used to suspend magnetically Positioning the impeller in the housing according to the signal   The rotation speed of the impeller depends on the signals received from the input and output of the pump. That is, a method of adjusting the flow velocity of the fluid.