A position-controlled suspension centrifugal blood pump

Abstract

The embodiment of this specification relates to a position-controlled suspension centrifugal blood pump, which is a "pump-motor integrated" device. The blood pump includes: a pump housing, a rotor, an impeller, a servo motor, an inner magnetic core group, an outer magnetic ring group, and a position-control bearing; the rotor and the impeller are seamlessly connected. The rotor is arranged in the inner tube of the blood pump and is driven by the servo motor to drive the impeller to do work; the inner magnetic core group is composed of multiple round magnetic pieces and is built in the top end inside the rotor. The outer magnetic ring group is composed of multiple magnetic rings and is sleeved on the outer wall of the inner tube; the position-control bearing is composed of ceramic balls and ceramic sockets. The top end of the impeller blade has an inclined surface, which can generate hydrodynamic pressure when the pump is working. According to the technical solution of the present invention, the rotor and the impeller can be position-controlled and suspended in all directions, overcoming the friction effect of mechanical bearings. The internal structure of the pump is simple and smooth, which can greatly reduce hemolysis and thrombus complications; the blood pump is small in size and light in weight, with less surgical invasiveness, and can improve safety and practicability.

Description

Technical Field

[0001] The embodiments of this specification relate to the field of medical device technology, and specifically to a position-controlled suspended centrifugal blood pump. Background Art

[0002] Cardiovascular diseases seriously threaten human health. Millions of people die of heart failure every year. There is still no simple and efficient way to treat terminal heart failure for patients with advanced heart failure. Artificial hearts are considered the last straw for many patients with advanced heart failure.

[0003] The ventricular assist device is an auxiliary artificial heart, also known as a "blood pump". In recent years, it has been widely used in clinical practice, with a total of nearly 10,000 cases of clinical application each year. At present, the four most widely used products in the international market are from the United States, two of which are second-generation blood pumps and two are third-generation blood pumps. The second-generation blood pump is a bearing-type structure, and its main disadvantages are: the bearing is very easy to wear, which seriously restricts the life of the blood pump; due to bearing friction, the hemolysis caused is relatively serious; the third-generation blood pump is a magnetic suspension structure, although it has a long service life, but there are also new problems. The main problems are: first, the magnetic suspension structure is complex, which increases the volume of the blood pump and increases the invasiveness of the operation. For example, the volume and weight of the third-generation magnetic suspension blood pump HeartMate III are more than three times that of the second-generation blood pump Jarvik2000; second, the structure is complex, there are blood flow dead angles or even dead cavities, and complications such as thrombosis are prone to occur.

[0004] It can be seen that reducing the volume and weight of the suspended blood pump, simplifying the structure inside the pump, and reducing complications such as hemolysis and thrombosis are difficult problems that the blood pump needs to solve. Summary of the invention

[0005] The technical problem to be solved by the embodiments of this specification is to overcome the deficiencies of the prior art and provide a position-controlled suspended centrifugal blood pump with small size, light weight and simple structure.

[0006] To achieve the above objectives, the embodiments of this specification adopt the following technical solutions:

[0007] A position-controlled suspension centrifugal blood pump, comprising: a pump housing, a rotor, an impeller, a servo motor, an inner magnetic core group, an outer magnetic ring group and a position-controlled bearing; the rotor and the impeller are seamlessly connected, the rotor is arranged in an inner tube of the blood pump, the rotor is driven by the servo motor, and drives the impeller to do work;

[0008] The inner magnetic core group is composed of a plurality of circular magnetic sheets and is built into the top of the rotor. The outer magnetic ring group is composed of a plurality of magnetic rings and is sleeved on the outer wall of the inner tube.

[0009] The position control bearing consists of a ceramic ball and a ceramic socket. The ceramic ball is embedded in the lower end of the rotor impeller and exposes the rotor, and the ceramic socket is arranged below the ceramic ball.

[0010] Optionally, the inner magnetic core group consists of three circular magnetic sheets, and the outer magnetic ring group consists of two magnetic rings; or

[0011] the inner magnetic core group consists of four circular magnetic sheets, and the outer magnetic ring group consists of three magnetic rings; or

[0012] the inner magnetic core group consists of five circular magnetic sheets, and the outer magnetic ring group consists of four magnetic rings.

[0013] Optionally, the magnetic materials of the inner magnetic core group and the outer magnetic ring group are strong magnetic neodymium iron boron.

[0014] Optionally, the inclined surface at the middle part of the top of the impeller is a hydrodynamic pressure structure.

[0015] Optionally, the inclination angle of the inclined surface is 1-20°.

[0016] Optionally, the impeller is sheet-shaped and includes a plurality of blades, and the roots of the blades are connected to the rotor.

[0017] Optionally, the impeller includes 3-5 blades.

[0018] Optionally, the pump housing further includes: an inlet pipe, a pump chamber cover, and a lower pump chamber housing;

[0019] The inlet pipe includes an inlet bracket, an outer heat insulation sleeve, a middle sleeve, and an inner pipe;

[0020] The outer heat insulation sleeve, the middle sleeve, and the inner pipe are coaxially structured, and one end of the three is connected to the inlet bracket, and the other end is embedded in the pump chamber cover;

[0021] The pump chamber cover is circular and is concentrically connected to the inner pipe, and the outer circle is connected to the lower pump chamber housing;

[0022] The inner bottom of the lower pump chamber housing has a convex round platform, and there is a pump outlet on the side.

[0023] Optionally, the servo motor includes a rotor magnet, a stator iron core, and a stator winding;

[0024] The rotor magnet is placed inside the rotor, and the stator iron core and the stator winding are placed on the inner wall of the inlet pipe, that is, built-in between the inner pipe and the middle sleeve;

[0025] The rotor magnet is integrated with the rotor, and the stator iron core and the stator winding are integrated with the inlet pipe.

[0026] Optionally, the servo motor further includes a telecommunication transmission line, one end of which is connected to the stator winding and the other end extends outside the body and is connected to a control system.

[0027] The above at least one technical solution adopted in the embodiments of the present specification can achieve the following beneficial effects:

[0028] The magnetic suspension bearing provided by the present invention is a permanent magnet bearing, belonging to passive magnetic suspension, which does not require complex detection, feedback, and control systems, has a relatively simple structure and stable performance, and can greatly improve the technical reliability and use safety of the blood pump; the volume and weight of the blood pump are small, which can reduce the surgical invasiveness of the blood pump and improve its practicability; the internal structure of this fully suspended blood pump is simple and smooth, without dead cavities or blind corners, and can also effectively prevent thrombus formation. Description of the Drawings

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present specification or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present specification. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0030] Figure 1 It is a schematic cross-sectional view of the structure of the position-controlled suspension centrifugal blood pump provided by the embodiments of the present specification;

[0031] Figure 2 It is a schematic view of the structure of the position-controlled suspension centrifugal blood pump when starting provided by the embodiments of the present specification;

[0032] Figure 3 It is a schematic diagram of the force analysis of the rotor impeller provided by the embodiments of the present specification.

[0033] Explanation of the reference numerals in the drawings: Rotor magnet - 1, Stator iron core - 2, Stator winding - 3, Outer magnetic ring group - 4, Inner magnetic core group - 5, Telecommunication transmission line - 6, Inner tube - 7, Middle sleeve - 8, Outer heat insulation sleeve - 9, Inlet bracket - 10, Rotor - 11, Impeller - 12, Inclined surface - 13, Ceramic ball - 14, Ceramic socket - 15, Convex round platform - 16, Wedge-shaped groove - 17, Lower pump chamber shell - 18, Pump chamber cover - 19, Pump outlet - 20, Pump inlet - 21, Suture ring - 22, First backward axial force - F1, Second backward axial force - F2, Third backward axial force - F3, Forward axial force - F4. Detailed Embodiments

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this specification clearer, the technical solutions of the embodiments of this specification will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this specification, rather than all the embodiments. All other implementation manners obtained by those of ordinary skill in the art based on the embodiments in this specification without creative efforts belong to the scope protected by the embodiments of this specification.

[0035] The following further illustrates the specific implementation of the embodiments in conjunction with the accompanying drawings of the embodiments of this specification.

[0036] See Figures 1 to 3 , the embodiments of this specification provide a position-controlled suspension centrifugal blood pump, including: a pump device, a servo motor, and a position control system.

[0037] The pump device includes a pump housing, a rotor 11, and an impeller 12.

[0038] The pump housing includes an inlet pipe, a pump chamber cover 19, and a lower pump chamber housing 18.

[0039] The inlet pipe includes an inlet bracket 10, an outer heat insulation sleeve 9, a middle sleeve 8, and an inner pipe 7.

[0040] The outer heat insulation sleeve 9, the middle sleeve 8, and the inner pipe 7 are coaxially structured. One end of the three is connected to the inlet bracket 10, and the other end is connected to the pump chamber cover 19. The connection part needs to be welded to prevent leakage.

[0041] The inlet bracket 10 is convex, in order to prevent the blood pump from sucking the ventricular septum due to negative pressure during operation, resulting in the failure of the pump operation and embolism.

[0042] There is a cavity between the outer heat insulation sleeve 9 and the middle sleeve 8, which can play a role in heat resistance and temperature reduction, ensuring the safe and effective operation of the blood pump and the motor.

[0043] There is a suture ring 22 at the part of the outer heat insulation sleeve 9 close to the pump chamber cover 19, which is used to fix the blood pump to the cardiac apex.

[0044] The pump chamber cover 19 is circular, the central opening is concentrically connected to the inner pipe 7, and the outer circle is connected to the lower pump chamber housing 18. The connection part needs to be welded to prevent leakage.

[0045] There is a convex round platform 16 at the inner bottom of the lower pump chamber housing 18, and a pump outlet 20 on the side. After the pump chamber cover 19 is buckled on the lower pump chamber housing 18, a seal welding treatment is performed.

[0046] The rotor 11 and the impeller 12 are seamlessly connected as a whole.

[0047] The rotor 11 is driven by the servo motor to drive the impeller 12 to do work, so that blood continuously flows in from the pump inlet 21, and after centrifugation, flows out from the pump outlet 20.

[0048] The impeller 12 is in the shape of a sheet, and generally has four blades, the roots of which are connected to the rotor 11 and are evenly distributed.

[0049] Optionally, the impeller 12 has 3 blades or 5 blades.

[0050] The servo motor mainly includes a rotor magnet 1, a stator core 2, a stator winding 3 and a telecommunication transmission line 6.

[0051] The rotor magnet 1 is placed in the rotor 11; the stator core 2 and the stator winding 3 are placed in the sandwich between the middle sleeve 8 and the inner tube 7.

[0052] The telecommunication transmission line 6 is used to transmit electric energy and electric signals, one end of which is connected to the stator winding 3, and the other end extends outside the body and is connected to the control system.

[0053] Since the servo motor and the pump device are integrated, a "pump-motor integration" is formed.

[0054] The position control system includes a position control magnetic group, a position control bearing and a hydraulic pressure structure.

[0055] The position control magnetic group includes an inner magnetic core group 5 and an outer magnetic ring group 4. The inner magnetic core group 5 is composed of three circular magnetic sheets stacked together coaxially and built into the top of the rotor; the outer magnetic ring group 4 is composed of two magnetic rings stacked together coaxially and sleeved on the outer wall of the inner tube, and its axial installation position is close to the lower edge of the inner magnetic core group 5. The magnetic direction of the circular magnetic sheets and the magnetic rings is axial, and the stacking order is that the same poles are opposite and forcibly bonded together.

[0056] Optionally, the inner magnetic core group 5 can be composed of four circular magnetic sheets, and the outer magnetic ring group 4 can be composed of three magnetic rings; or the inner magnetic core group 5 can be composed of five circular magnetic sheets, and the outer magnetic ring group 4 can be composed of four magnetic rings, and the installation position is close to the bottom edge.

[0057] Preferably, the magnetic material of the position control magnetic group is strong magnetic neodymium iron boron.

[0058] The position-control bearing includes a ceramic ball 14 and a ceramic socket 15. The ceramic ball 14 is embedded in the lower end of the rotor impeller 12, exposing nearly half of it. The ceramic socket 15 is embedded in the top of the convex cone 16, and the edges are flush. Under the axial pressure generated by the position-control magnetic group, the ceramic ball 14 presses against the ceramic socket 15 to form a group of sliding bearings, which can well support the start-up of the position-control blood pump. Figure 2 shown.

[0059] The hydraulic pressure structure is such that the middle part at the top of the impeller 12 is inclined, that is, the middle part of the blade top is inclined from the inlet flow-receiving edge to the backflow edge. This inclined surface 13 forms a wedge-shaped space with the inner surface of the pump chamber cover 19, and there are edges flush with the top surface on both sides of the inclined surface to prevent the overflow of the liquid flow. When the pump is working, under the action of centrifugal force, the liquid flow enters the wedge-shaped groove 17, and hydraulic pressure is generated due to extrusion. The axial force pushes the blade, so that the blade can never contact the pump chamber cover 19.

[0060] Optionally, the inclination angle of the inclined surface 13 is 1-20°.

[0061] After a controllable-position suspension centrifugal blood pump provided in an embodiment of this specification starts smoothly, it is necessary to analyze how the rotor impeller achieves suspended operation as shown in the figure. Suspension can be decomposed into radial suspension and axial suspension. Figure 1 As shown in the figure, to achieve suspended operation, it is necessary to analyze. Suspension can be decomposed into radial suspension and axial suspension.

[0062] Radial suspension is mainly achieved by the controllable-position magnetic group. The inner magnetic core group 5 and the outer magnetic ring group 4 are radially repelled by magnetic force, and the repulsive force is sufficient to overcome and balance various radial forces, so that the rotor impeller is always positioned at the center of the inner tube 7. Coupled with the gyroscopic fixed-axis effect when the rotor impeller rotates, a good radial suspension effect can be obtained.

[0063] To achieve axial suspension, it is necessary to analyze the axial force. When the blood pump is working at high speed, it will be affected by multiple axial forces, which can be divided into weak axial forces and strong axial forces. The weak axial forces mainly include the axial component of the gravity of the rotor impeller and the axial forces of other factors, which are weak influencing factors; the strong axial forces mainly include four axial forces, which can be from Figure 3As shown in the figure, F4 is the forward axial force (pointing to the pump inlet), F1, F2, and F3 are three backward axial forces (backward to the pump inlet), F1 is generated by the position-controlled magnetic group. Because the inner magnetic core group 5 has one more piece than the outer magnetic ring group 4 and is slightly higher, it generates a backward axial pressure on the rotor impeller. This force is small, but the magnitude is basically unchanged, and has nothing to do with the speed of the pump; F2 is the axial component of the impulse generated by the liquid flow momentum on the impeller, and the magnitude of this force is positively correlated with the speed; F3 is the axial component of the pressure exerted by the hydraulic pressure on the inclined surface 13 of the impeller 12, and the magnitude of this force is positively correlated with the speed in geometric series, but negatively correlated with the size of the wedge-shaped space; F4 is due to the pump cavity cover 1 when the pump is working. 9 is generated by the pressure difference between the low hydraulic pressure on the inner surface and the suction port and the high hydraulic pressure on the lower cover surface. After the pump is started, the force increases rapidly with the increase of the pump speed. When the speed reaches a certain height and F4 is greater than the sum of F1, F2, and F3, F4 drives the rotor impeller and the ceramic ball 14 to break away from the ceramic socket 15 and move axially forward. As the top of the blade approaches the pump chamber cover 19, the wedge-shaped space becomes smaller, and the axial component F3 of the generated hydraulic pressure increases exponentially. This force will automatically counteract F4. When the resultant axial force is balanced, the rotor impeller is forced to stop axial displacement, and F3 no longer increases. In other words, within a certain speed range, the axial force on the rotor impeller can be automatically balanced and automatically axially suspended.

[0064] As mentioned above, the radial suspension of the rotor impeller combined with the axial suspension can achieve all-round position-controlled suspension, thereby operating smoothly.

[0065] The technical effects that can be achieved by the embodiments of this specification are as follows:

[0066] Compared with the existing mechanical bearing blood pump, the blood pump of the embodiment of the present specification is in a suspended state during normal operation, and the bearing has no friction, which can reduce hemolysis, extend the life of the blood pump, and reduce thrombotic complications triggered by frictional heat.

[0067] Compared with the existing magnetic levitation blood pump, the suspension bearing of the embodiment of this specification is a permanent magnetic bearing, which belongs to passive magnetic levitation and does not require complex detection, feedback, and control systems. It has a simple structure and stable performance, which can greatly improve the technical reliability and safety of use of the blood pump; the blood pump is small in size and weight, which can reduce the surgical invasiveness of the blood pump and improve its practicality; the internal structure of this fully suspended blood pump is simple and smooth, without dead space or dead corners, and can also effectively prevent thrombosis.

[0068] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc., mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0069] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A position-controlled suspension centrifugal blood pump, characterized in that, Comprising: A pump housing, a rotor, an impeller, a servo motor, an inner magnetic core group, an outer magnetic ring group, and a positioning bearing; the rotor and the impeller are seamlessly connected, the rotor is arranged in the inner tube of the blood pump, and the rotor is driven by the servo motor to drive the impeller to do work; The inner magnetic core group is built in the top end inside the rotor, and the outer magnetic ring group is sleeved on the outer wall of the inner tube; wherein, the inner magnetic core group is composed of three circular magnetic pieces, and the outer magnetic ring group is composed of two magnetic rings; or the inner magnetic core group is composed of four circular magnetic pieces, and the outer magnetic ring group is composed of three magnetic rings; or the inner magnetic core group is composed of five circular magnetic pieces, and the outer magnetic ring group is composed of four magnetic rings; the inner magnetic core group and the outer magnetic ring group are used in cooperation to generate an axial backward pressure on the rotor; The positioning bearing is composed of a ceramic ball and a ceramic socket, the ceramic ball is embedded inside the lower end of the rotor impeller and exposes the rotor, and the ceramic socket is arranged below the ceramic ball; The impeller is sheet-shaped and includes a plurality of blades, and the roots of the blades are connected to the rotor; the inclined surface at the middle part of the top of the impeller is a hydrodynamic pressure structure, that is, the middle part of the top of the blade is inclined from the inlet flow-receiving edge to the back-flow edge, and the inclined surface forms a wedge-shaped space with the inner surface of the pump chamber cover of the pump housing.

2. The blood pump according to claim 1, characterized in that, Both the inner magnetic core group and the outer magnetic ring group are bonded together by the repulsive force of the same polarity of the strong magnetic neodymium iron boron material.

3. The blood pump according to claim 1, characterized in that, The inclination angle of the inclined surface is 1-20°.

4. The blood pump according to claim 1, wherein The impeller includes 3-5 blades.

5. The blood pump according to claim 1, wherein, The pump housing includes: an inlet pipe, a pump chamber cover, and a pump chamber lower housing; The inlet pipe includes an inlet bracket, an outer heat insulation sleeve, a middle sleeve, and an inner tube; The outer heat insulation sleeve, the middle sleeve, and the inner tube are of a coaxial structure, and one end of the three is connected to the inlet bracket, and the other end is embedded in the pump chamber cover; The pump chamber cover is circular and is concentrically connected to the inner tube, and the outer circle is connected to the pump chamber lower housing; There is a convex round platform at the inner bottom of the pump chamber lower housing, and a pump outlet is arranged on the side.

6. The blood pump according to claim 5, wherein, The servo motor includes a rotor magnet, a stator iron core, and a stator winding; The rotor magnet is arranged inside the rotor, and the stator iron core and the stator winding are arranged on the inner wall of the inlet pipe, that is, built between the inner tube and the middle sleeve; The rotor magnet is integrated with the rotor, and the stator iron core and the stator winding are integrated with the inlet pipe.

7. The blood pump according to claim 6, characterized in that, The servo motor further includes a telecommunication transmission line, one end of the telecommunication transmission line is connected to the stator winding, and the other end extends outside the body and is connected to a control system.

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