Shafting eccentricity compensation type extracorporeal control device for micro axial flow blood pump

Abstract

The application discloses a shafting eccentric compensation type extracorporeal control device for a micro axial flow blood pump, which comprises a master control device and a driven device. The master control device comprises a master control shell, a motor and a driving part are arranged in the master control shell, and first and second driving permanent magnets are arranged on the driving part. The driven device comprises a driven shell, a driven cavity and a channel cavity are separated by a partition plate in the driven shell, the channel cavity is connected with the micro axial flow blood pump through a catheter, the channel cavity is connected with a perfusion tube, a driven part is arranged in the driven cavity, first and second driven permanent magnets are arranged on the driven part, and a hard shaft of the driven part is connected with an impeller through a soft shaft after passing through the partition plate and the channel cavity. After the driven device is embedded in a placing groove of the master control device, the first driven permanent magnet is axially opposite to the first driving permanent magnet, and the second driven permanent magnet is radially opposite to the second driving permanent magnet. The application realizes shafting eccentric compensation, solves the problem of difficult shaft centering of a small-diameter shafting, adopts a radial and axial double coupling mode, and ensures the stability of magnetic coupling.

Description

Technical Field

[0001] This invention relates to an external control device for shaft eccentricity compensation in a miniature axial flow blood pump, belonging to the technical field of miniature axial flow blood pump drive equipment. Background Technology

[0002] Miniature axial flow blood pumps have been widely used in the clinical treatment of heart failure due to their advantages such as rapid intervention and small incision. They generate axial thrust through the high-speed rotation of the impeller, which pushes blood to flow along the pump axis, thereby assisting or replacing the heart's pumping function and maintaining the perfusion of tissues throughout the body.

[0003] Currently, miniature axial flow blood pumps are mainly driven by two types of motors: internal and external. External motor drives are more commonly used because they do not have special requirements for the motor. However, in practical applications, external motor drives present some problems: the flexible drive shaft (soft shaft) is positioned and supported by bearings inside the pump and connected to the impeller. When the flexible drive shaft drives the impeller to rotate at high speed under motor drive, friction generates heat between the flexible drive shaft and bearings. Therefore, flushing fluid is usually introduced to reduce temperature and wear. Since the flushing fluid is introduced from outside the body, isolation between the flushing fluid and the external motor is crucial. Existing practices include shaft sealing of the inlet tube connected to the motor output shaft for flushing fluid introduction; however, this approach carries the risk of flushing fluid leakage, which can easily lead to contamination of the flushing fluid, affecting the normal operation of the equipment and the patient's safety.

[0004] To address the aforementioned issues, a magnetic transmission device was introduced. This non-contact transmission device transmits power based on magnetic coupling. It primarily consists of an active end and a driven end, each equipped with a magnet. The active end is driven by a motor, transmitting power to the driven end non-contactly via magnetic coupling. The driven end then drives a flexible drive shaft along an impeller to transmit power. This transmission method, with no direct mechanical contact between the active and driven ends, ensures that the flushing fluid flows only at the driven end, effectively rinsing the flexible drive shaft and preventing the flushing fluid from entering the external motor, thus preventing leakage and contamination. See, for example, the invention patent application "Quick-Connect Magnetic Transmission Device for Medical Interventional Instruments" (Publication No. CN110743051B). However, existing magnetic drive devices still have drawbacks: First, miniature axial flow blood pumps operate at extremely high speeds, typically 30,000-50,000 rpm. Under these conditions, for small-diameter shaft systems (shafts with a diameter of less than 2 mm are considered small-diameter shafts), aligning the drive and driven ends is very difficult. This leads to slight eccentricity during operation, and the rigid structures supporting the magnets on both ends are insufficient to compensate for this eccentricity, easily resulting in decreased magnetic coupling effectiveness or even decoupling. Second, the magnetic coupling between the magnets on the drive and driven ends generally adopts radial or axial coupling modes. This single coupling mode cannot ensure the stability of magnetic coupling under high torque operation.

[0005] Therefore, how to solve the problems of shaft eccentricity and magnetic coupling stability under high-speed rotation of the blood pump is an urgent problem to be solved. Summary of the Invention

[0006] The purpose of this invention is to provide an external control device for shaft eccentricity compensation for a miniature axial flow blood pump. It achieves shaft eccentricity compensation, solves the problem of difficult shaft alignment for small diameter shafts, and adopts a dual coupling mode of radial and axial forces to ensure the stability of magnetic coupling.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: An axial eccentricity-compensated external control device for a miniature axial flow blood pump includes a main control device and a driven device. The main control device includes a main control housing containing a motor and an active component. A first and second active permanent magnet are mounted on the active component. The driven device includes a driven housing containing a driven chamber and a channel chamber separated by a partition. The channel chamber is connected to the miniature axial flow blood pump via a catheter and is also connected to an infusion tube. A driven component is located within the driven chamber, and a first and second driven permanent magnet are mounted on it. The rigid shaft of the driven component passes through the partition and the channel chamber, and then connects to the pump via a flexible shaft. The impeller of the miniature axial flow blood pump is connected, wherein the flushing fluid delivered from the infusion tube enters the catheter and the driven chamber; when the driven device is embedded in the placement slot of the main control device, the first driven permanent magnet is axially opposite to the first active permanent magnet and the second driven permanent magnet is radially opposite to the second active permanent magnet, so that when the active component rotates under the drive of the motor, the driven component is driven to rotate through magnetic coupling by means of the first driven permanent magnet and the first active permanent magnet, so that the driven component drives the impeller to rotate by means of the flexible shaft, and shaft eccentricity compensation is achieved by means of the second driven permanent magnet and the second active permanent magnet.

[0008] The advantages of this invention are: In addition to the advantages of preventing flushing fluid from entering the external motor and causing leakage and contamination, and achieving only flushing and cooling of the flexible shaft to reduce wear, this invention also addresses the problem of difficult shaft alignment for small-diameter shaft systems by using a design of a second active permanent magnet and a second driven permanent magnet on the cantilever to achieve eccentricity compensation, preventing a decrease in magnetic coupling effect and avoiding decoupling. Furthermore, this invention adopts a radial and axial dual coupling mode, ensuring the stability of magnetic coupling under high torque operation and preventing decoupling. The normal operation of the entire device and the patient's life safety are guaranteed. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the composition of the shaft system eccentricity compensation type external control device of the present invention.

[0010] Figure 2 This is a cross-sectional schematic diagram of the shaft system eccentricity compensation type external control device of the present invention.

[0011] Figure 3 This is a cross-sectional schematic diagram of the main control device.

[0012] Figure 4 This is a cross-sectional schematic diagram of the driven device.

[0013] Figure 5 This is a three-dimensional structural diagram of the active component.

[0014] Figure 6 This is a three-dimensional structural diagram of the driven component.

[0015] Figure 7 This is a schematic diagram of the structure of a miniature axial flow blood pump.

[0016] Figure 8 This is an example diagram illustrating the application scenario of the shaft eccentricity compensation type external control device of the present invention. Detailed Implementation

[0017] like Figures 1 to 8 As shown, this invention proposes an axial eccentricity-compensated external control device for a miniature axial flow blood pump, comprising a main control device 10 and a driven device 20. The main control device 10 includes a main control housing 101, within which a motor 93 and an active component 30 are disposed. A first active permanent magnet 31 and a second active permanent magnet 35 are mounted on the active component 30. The driven device 20 includes a driven housing 21, within which a driven cavity 23 and a channel cavity 24 are separated by a partition 22. The channel cavity 24 is connected to the miniature axial flow blood pump 80 via a catheter 60, and an infusion tube 701 is connected to the channel cavity 24. A driven component 50 is disposed within the driven cavity 23, on which a first driven permanent magnet 51 and a second driven permanent magnet 56 are mounted. The hard shaft 54 ​​of the driven component 50... After passing through the partition 22 and the channel cavity 24, it is connected to the impeller 83 of the micro axial flow blood pump 80 via the flexible shaft 61. The flushing fluid (high pressure) delivered from the perfusion tube 701 enters the catheter 60 and the driven cavity 23. When the driven device 20 is installed in the placement slot 15 of the main control device 10, the first driven permanent magnet 51 and the first active permanent magnet 31 are axially opposite each other, and the second driven permanent magnet 56 and the second active permanent magnet 35 are radially opposite each other. When the active member 30 is driven by the motor 93 to rotate by means of the first driven permanent magnet 51 and the first active permanent magnet 31, the driven member 50 is driven to rotate by magnetic coupling. The driven member 50 drives the impeller 83 to rotate by means of the flexible shaft 61, and the shaft eccentricity compensation is achieved by means of the second driven permanent magnet 56 and the second active permanent magnet 35.

[0018] like Figure 3 and Figure 5 The active component 30 includes a circular support disk 32. Multiple first active permanent magnets 31 are evenly distributed along the circumferential direction on one end face of the support disk 32, and multiple sheet-like cantilever arms 34 extend along the circular edge at intervals. The cantilever arms 34 are arranged axially, and each cantilever arm 34 is fitted with a second active permanent magnet 35. A rotating shaft 33 is provided at the center of the other end face of the support disk 32. The rotating shaft 33 is rotatably connected to the support bearing 14 on the support plate 11 provided in the main control housing 101.

[0019] In practical design, preferably, the first active permanent magnet 31 is engaged in the first slot 310 provided on the support disk 32, and the gap between adjacent first active permanent magnets 31 is reasonably designed according to requirements. Figure 5 Preferably, the second active permanent magnet 35 is embedded in the inner wall of the cantilever 34, and there should be a certain distance between adjacent cantilever 34s. The gap between adjacent second active permanent magnets 35 is reasonably designed according to requirements. The support bearing 14 includes an inner ring and an outer ring that are rotatably connected by balls. The outer ring is fixed to the support plate 11, and the inner ring is fixedly connected to the rotating shaft 33.

[0020] In practical design, the cantilever 34 should be made of non-magnetic material and be a thin sheet, usually a curved thin sheet (such as...). Figure 5 Preferably, the cantilever 34 is made of titanium alloy (such as nickel-titanium alloy) with a thickness between 1mm and 3mm. Alternatively, the overall thickness of the second active permanent magnet 35 after being embedded in the cantilever 34 is 1mm-3mm. The thin-sheet design of the cantilever 34 allows it to have a certain degree of flexibility, thus producing micro-deformation under the centrifugal force generated by high-speed rotation, i.e., slight bending in the radial direction.

[0021] Furthermore, the output shaft 930 of the motor 93 is connected to the end of the rotating shaft 33 extending from the support plate 11. The motor 93 is wired to the controller 91 located in the main control housing 101. That is, the active component 30 is radially positioned by the support bearing 14 and axially positioned by the fixed connection with the motor 93, ensuring that the active component 30 does not deviate during rotation.

[0022] In actual design, the output shaft 930 of the motor 93 can be inserted into the fixing hole (not shown) on the rotating shaft 33, which is of course unrestricted.

[0023] In actual design, the main control housing 101 can be divided into a first chamber 121 and a second chamber 122 by a support plate 11. The first chamber 121 is used to house the active component 30, and the second chamber 122 is used to house the motor 93 and the controller 91, etc.

[0024] Better, such as Figure 1 and Figure 2 The main control housing 101 may be provided with a handheld hole 13. Additionally, the main control housing 101 may be provided with heat dissipation holes (not shown), such as... Figure 1 .

[0025] like Figure 2 The main control housing 101 is equipped with a display module 92 (such as a display screen), which is wired to the controller 91. The display module 92 is used to display parameters such as the motor speed and running time of the motor 93.

[0026] like Figure 4 and Figure 6The driven member 50 includes a circular turntable 52. A support shaft 53 is provided at the center of one end face of the turntable 52, and a plurality of first driven permanent magnets 51 are evenly distributed around the support shaft 53 in the circumferential direction. A cylindrical mounting base 55 is provided on the other end face of the turntable 52. A plurality of second driven permanent magnets 56 are provided on the mounting base 55. The second driven permanent magnets 56 are evenly distributed in the circumferential direction. The mounting base 55 is connected to a rigid shaft 54, and the rigid shaft 54 ​​is opposite to the support shaft 53.

[0027] Furthermore, such as Figure 4 The support shaft 53 is rotatably connected to the first bearing 28 on the inner wall of the driven housing 21, and the rigid shaft 54 ​​is rotatably connected to the second bearing 29 on the partition plate 22. That is, the driven member 50 is radially and axially positioned in the driven cavity 23 by means of the first bearing 28 and the second bearing 29, ensuring that the driven member 50 does not deviate during rotation.

[0028] When the driven device 20 is installed in the placement slot 15 of the main control device 10 (a portion of the driven device 20 is placed in the placement slot 15), on the one hand, the first driven permanent magnet 51 and the first active permanent magnet 31 are opposite in the axial direction. More precisely, the polarities of the opposite end faces of the first driven permanent magnet 51 and the first active permanent magnet 31 are opposite (for example, the end face of the first driven permanent magnet 51 facing the first active permanent magnet 31 is the N pole, and the end face of the first active permanent magnet 31 facing the first driven permanent magnet 51 is the S pole). There is only the main control housing 101 and the driven housing 21 between the first driven permanent magnet 51 and the first active permanent magnet 31, so that the first driven permanent magnet 51 can be driven to rotate by the first active permanent magnet 31 through magnetic coupling. On the other hand, the second driven permanent magnet 56 and the second active permanent magnet 35 are opposite in the radial direction. More precisely, the polarities of the opposite end faces of the second driven permanent magnet 56 and the second active permanent magnet 35 are opposite. With opposite polarities (for example, if the end face of the second driven permanent magnet 56 facing the second active permanent magnet 35 is the N pole, then the end face of the second active permanent magnet 35 facing the second driven permanent magnet 56 is the S pole), there should be a certain distance between the second driven permanent magnet 56 and the second active permanent magnet 35 so that a certain magnetic coupling effect can be generated between the second driven permanent magnet 56 and the second active permanent magnet 35. When the driven member 50 is eccentric (caused by assembly or during rotation), the cantilever 34 can generate a slight deformation (radial bending) under the action of centrifugal force according to the change in the distance between the second active permanent magnet 35 and the second driven permanent magnet 56 (i.e., the magnetic force between a certain part of the second driven permanent magnet 56 and the second active permanent magnet 35 changes due to the eccentricity of the driven member 50) to correct the rotational position of the driven member 50. That is, to achieve eccentricity compensation for the driven member 50, so that the driven member 50 and the active member 30 always maintain a good axial alignment state. Meanwhile, the air gap between the second driven permanent magnet 56 and the second active permanent magnet 35 can prevent resonance between the two and ensure rotational stability.

[0029] In actual design, the shape of the placement slot 15 is adapted to the shape of the driven housing 21. For example... Figure 3 and Figure 4 The bottom of the placement groove 15 is flat, and the side of the driven housing 21 that contacts the bottom of the placement groove 15 is a flat plate 210.

[0030] In practical design, preferably, the first driven permanent magnet 51 is engaged in the second slot 510 provided on the turntable 52, and the gap between adjacent first driven permanent magnets 51 is designed reasonably as needed. The second driven permanent magnet 56 is generally embedded in the side wall of the cylindrical mounting base 55, and the gap between adjacent second driven permanent magnets 56 is designed reasonably as needed. The turntable 52, support shaft 53, mounting base 55, and rigid shaft 54 ​​are coaxially arranged. The first bearing 28 includes an inner ring and an outer ring rotatably connected by balls; the outer ring is fixed to the flat plate 210 of the driven housing 21, and the inner ring is fixedly connected to the support shaft 53. The second bearing 29 includes an inner ring and an outer ring rotatably connected by balls; the outer ring is fixed to the partition plate 22, and the inner ring is fixedly connected to the rigid shaft 54. Figure 4 The first bearing 28 is non-penetratingly mounted on the plate 210, while the second bearing 29 can be either penetratingly mounted on the partition plate 22.

[0031] In practical applications, the driven device 20 can be placed in the placement slot 15 without being fixed. The driven device 20 can be stably placed in the placement slot 15 by the magnetic attraction between the first driven permanent magnet 51 and the first active permanent magnet 31. Of course, the driven device 20 can also be placed in the placement slot 15 by means of detachable snap-fit, etc., without restriction.

[0032] In this invention, the number and arrangement (including gaps) of the first driven permanent magnet 51 and the first active permanent magnet 31 should be consistent, and the number and arrangement (including gaps) of the second driven permanent magnet 56 and the second active permanent magnet 35 should be consistent. The first driven permanent magnet 51, the first active permanent magnet 31, the second driven permanent magnet 56, and the second active permanent magnet 35 can be made of hot-pressed neodymium iron boron material, without limitation.

[0033] like Figure 4 The channel cavity 24 is provided with an output channel 25. One end of the output channel 25 is fixed to the partition 22 and the other end is connected to the conduit 60. The rigid shaft 54 ​​of the driven member 50 passes through the partition 22 and the output channel 25 and then extends into the conduit 60. The middle part of the output channel 25 is connected to the infusion pipe 701 via the infusion channel 26. The high-pressure flushing fluid sent by the infusion pipe 701 enters the output channel 25 via the infusion channel 26 and then enters the conduit 60 and the driven cavity 23.

[0034] like Figure 1 and Figure 2 The infusion pipe 701 is connected to the infusion assembly 70, which is used to connect to the flushing fluid supply equipment. The infusion assembly 70 includes an infusion valve. The infusion valve can be independently controlled, either automatically or manually.

[0035] In practical applications, the output channel 25 is located between the partition 22 and the driven housing 21. Preferably, the output channel 25 passes through the driven housing 21. The conduit 60 extends into the output channel 25 and is fixedly connected to the inner wall of the output channel 25. Preferably, the rigid shaft 54 ​​extends out of the output channel 25, enters the conduit 60, and connects to the flexible shaft 61. The rigid shaft 54 ​​and the flexible shaft 61 can be connected by means of bonding, welding, etc.

[0036] In this invention, the shaft diameters of the rotating shaft 33 of the driving member 30 and the support shaft 53 and rigid shaft 54 ​​of the driven member 50 are generally less than 2 mm, forming a small-diameter shaft system. Therefore, during the assembly of the driven member 50 or during the high-speed rotation of the driven member 50, the driven member 50 often experiences eccentricity. To address this problem, this invention effectively compensates for the eccentricity of the driven member 50 during the rotation of the driven member 50 by the magnetic coupling design between the second driven permanent magnet 56 and the second driving permanent magnet 35 mounted on the cantilever 34.

[0037] In this invention, the driving member 30 and the driven member 50 are axisymmetric structures. The axial and radial directions mentioned in this article refer to the axial direction and radial direction of the driving member 30 or the driven member 50, respectively.

[0038] like Figure 7 The miniature axial flow blood pump 80 includes an inlet cage 81, one end of which is open to form an inlet 86 and is equipped with a support frame 82. The other end of the inlet cage 81 is closed by a base 84. An impeller 83 is disposed inside the inlet cage 81 and is connected to a flexible shaft 61 rotatably mounted on the base 84. An outlet (not shown) is provided on the side wall of the inlet cage 81. In practical applications, blood enters through the inlet 86 and is ejected obliquely from the outlet under the action of the high-speed rotating impeller 83 (see...). Figure 7 (See arrow).

[0039] In practical design, the flexible shaft 61 is rotatably mounted on the base 84 via a blood pump bearing 85. The blood pump bearing 85 includes an inner ring and an outer ring rotatably connected by balls. The outer ring is fixed to the base 84, and the inner ring is fixedly connected to the flexible shaft 61. Preferably, the flexible shaft 61 is connected to two blood pump bearings 85 to improve the positioning and rotational stability of the flexible shaft 61.

[0040] In this invention, components that may come into contact with blood, such as the catheter 60, the flexible shaft 61, and components in the driven device 20 other than the first and second driven permanent magnets 51 and 56, must be made of biocompatible materials. The flexible shaft 61 can be made of biocompatible materials such as stainless steel or carbon fiber composites and processed by multi-strand winding. The driven housing 21, output channel 25, infusion channel 26, rigid shaft 54, turntable 52, support shaft 53, and partition 22 can be made of biocompatible materials such as titanium alloys (e.g., nickel-titanium alloys). The first and second driven permanent magnets 51 and 56 need to be wrapped with a biocompatible thin film (0.2mm-0.5mm). Components on the main control housing 101 and the active component 30 other than the first and second active permanent magnets 31 and 35 can also be made of titanium alloys (e.g., nickel-titanium alloys), and are not limited thereto.

[0041] Here, the miniature axial flow blood pump 80 is an existing device in the field, and its structure can vary widely, unaffected by... Figure 7 The structure shown is subject to constraints.

[0042] The purge fluid involved in this invention is a commonly used liquid in the field. It is a liquid used to prevent blood from forming biological contamination in the blood pump and to maintain the cleanliness of mechanical gaps, such as a glucose aqueous solution containing heparin, and is of course not limited to this.

[0043] In use, the miniature axial flow blood pump 80 is placed at the target position in the patient's body, and the driven device 20 is placed in the placement slot 15 of the main control device 10 (the driven device 20 is stably placed due to the magnetic attraction between the first active permanent magnet 31 and the first driven permanent magnet 51). At this time, the first driven permanent magnet 51 and the first active permanent magnet 31 are axially opposite each other, and the second driven permanent magnet 56 and the second active permanent magnet 35 are radially opposite each other. Then, the perfusion assembly 70 is connected to the flushing fluid supply device.

[0044] Then, the controller 91 is started, the motor 93 runs, driving the first active permanent magnet 31 and the second active permanent magnet 35 of the active component 30 to rotate at high speed. Then, the first active permanent magnet 31 of the active component 30 drives the first driven permanent magnet 51 of the driven component 50 to rotate at high speed through magnetic coupling (magnetic attraction). Thus, the rigid shaft 54 ​​of the driven component 50 drives the impeller 83 to rotate through the flexible shaft 61, so that the impeller 83 completes the effect of pushing blood to flow along the pump shaft direction. The micro axial flow blood pump 80 completes the blood pumping function. Simultaneously, magnetic coupling also occurs between the second driven permanent magnet 56 and the second active permanent magnet 35. When the driven member 50 becomes eccentric, the distance between the second active permanent magnet 35 and the second driven permanent magnet 56 changes, meaning the magnetic force between a portion of the second driven permanent magnet 56 and the second active permanent magnet 35 changes. Consequently, the cantilever 34 undergoes slight deformation under centrifugal force, adjusting the magnetic force between the second active permanent magnet 35 and the second driven permanent magnet 56 to correct the rotational position of the driven member 50. This achieves eccentricity compensation for the small-diameter shaft system, ensuring stable rotation of the driven member 50 and preventing a decrease in magnetic coupling effect or even decoupling. Furthermore, the air gap between the second driven permanent magnet 56 and the second active permanent magnet 35 prevents resonance between them. In addition, this invention forms a radial and axial dual coupling mode, ensuring the stability of magnetic coupling under high torque operation and effectively preventing decoupling.

[0045] Here, the rotation of the first driven permanent magnet 51 of the driven member 50 is not directly driven by the motor 93, but is driven by the magnetic coupling effect generated by the first active permanent magnet 31 of the active member 30. This design avoids the risk of leakage of flushing fluid into the external motor 93 and avoids contamination.

[0046] Simultaneously, the infusion valve is opened, and the flushing fluid supplied by the high-pressure flushing fluid supply equipment enters the output channel 25 through the infusion pipe 701 and infusion channel 26. Then, 90% of the flushing fluid enters the conduit 60 and is then sent to the base 84 of the miniature axial flow blood pump 80. This reduces the temperature of the flexible shaft 61 and the blood pump bearing 85 during the high-speed rotation of the impeller 83, preventing frictional heating and high temperatures. It also flushes and cleans the blood entering the gap between the flexible shaft 61 and the blood pump bearing 85, reducing wear between them (lubrication effect). On the other hand, 10% of the flushing fluid enters the driven chamber 23 through the partition 22 and the second bearing 29, cooling the high-speed rotating driven component 50 and reducing wear between the driven component 50 and the first bearing 28 and the second bearing 29 (lubrication effect).

[0047] In practical applications, this invention can be used in scenarios such as renal perfusion, left ventricular assist, and right ventricular assist. For example, when used for renal perfusion, such as... Figure 8The miniature axial flow blood pump 80 is inserted into the descending aorta (DAO) of the patient via the femoral artery (FA). The impeller 83 accelerates the blood flow within the pump to entrain blood flow outside the pump, thereby increasing the overall downward velocity of blood flow and affecting renal artery perfusion. When used for left ventricular assist, this invention can reduce proximal aortic resistance and increase distal aortic flow, thereby reducing left ventricular afterload and improving cardiac output.

[0048] The advantages of this invention are: In addition to its advantages of preventing leakage and contamination of the external motor by flushing fluid, and achieving only flushing, cooling, and reduced wear on the flexible shaft, this invention also addresses the challenge of aligning small-diameter shaft systems by using a design of a second active permanent magnet and a second driven permanent magnet on the cantilever to achieve eccentricity compensation. This prevents a decrease in magnetic coupling effectiveness and avoids decoupling. Furthermore, this invention adopts a dual-coupling mode of radial and axial forces: the first active permanent magnet and the first driven permanent magnet are magnetically coupled axially, while the second active permanent magnet and the second driven permanent magnet are magnetically coupled radially. This fully utilizes space, ensures the stability of magnetic coupling under high-torque operation, and prevents decoupling. The normal operation of the entire device and the patient's safety are thus guaranteed.

[0049] The above description describes the preferred embodiments of the present invention and the technical principles applied thereto. For those skilled in the art, any obvious changes such as equivalent transformations or simple substitutions based on the technical solutions of the present invention, without departing from the spirit and scope of the present invention, shall fall within the protection scope of the present invention.

Claims

1. An external control device for shaft eccentricity compensation in a miniature axial flow blood pump, characterized in that, The device includes a main control unit and a driven unit. The main control unit includes a main control housing, within which a motor and an active component are housed. A first and a second active permanent magnet are mounted on the active component. The driven unit includes a driven housing, within which a driven chamber and a channel chamber are separated by a partition. The channel chamber is connected to a miniature axial flow blood pump via a conduit and is also connected to an infusion tube. A driven component is housed within the driven chamber, and a first and a second driven permanent magnet are mounted on the driven component. The rigid shaft of the driven component passes through the partition and the channel chamber, and is then connected to the impeller of the miniature axial flow blood pump via a flexible shaft. In the process, the flushing fluid delivered from the infusion tube enters the conduit and the driven cavity; when the driven device is embedded in the placement slot of the main control device, the first driven permanent magnet and the first active permanent magnet are axially opposite each other and the second driven permanent magnet and the second active permanent magnet are radially opposite each other, so that when the active component rotates under the drive of the motor by means of the first driven permanent magnet and the first active permanent magnet, the driven component is driven to rotate by magnetic coupling, so that the driven component drives the impeller to rotate by means of the flexible shaft, and shaft eccentricity compensation is achieved by means of the second driven permanent magnet and the second active permanent magnet.

2. The shaft eccentricity-compensated external control device for a miniature axial flow blood pump as described in claim 1, characterized in that, The active component includes a circular support disk. A plurality of first active permanent magnets are evenly distributed along the circumference of one end face of the support disk, and a plurality of sheet-like cantilever arms extend along the circular edge at intervals. Each cantilever arm is fitted with a second active permanent magnet. A rotating shaft is provided at the center of the other end face of the support disk. The rotating shaft is rotatably connected to a support bearing on a support plate provided inside the main control housing.

3. The shaft eccentricity-compensated external control device for a miniature axial flow blood pump as described in claim 2, characterized in that, The cantilever is made of titanium alloy with a thickness between 1mm and 3mm.

4. The shaft eccentricity-compensated external control device for a miniature axial flow blood pump as described in claim 2, characterized in that, The output shaft of the motor is connected to the end of the rotating shaft that extends out of the support plate, and the motor is connected to a controller located inside the main control housing.

5. The shaft eccentricity-compensated external control device for a miniature axial flow blood pump as described in claim 2, characterized in that, The driven component includes a circular turntable. A support shaft is provided at the center of one end face of the turntable, and a plurality of first driven permanent magnets are evenly distributed around the support shaft in the circumferential direction. A mounting base is provided on the other end face of the turntable, and a plurality of second driven permanent magnets are provided on the mounting base. Each second driven permanent magnet is evenly distributed in the circumferential direction. The mounting base is connected to the rigid shaft, and the rigid shaft is opposite to the support shaft.

6. The shaft eccentricity-compensated external control device for a miniature axial flow blood pump as described in claim 5, characterized in that, The support shaft is rotatably connected to the first bearing on the inner wall of the driven housing, and the rigid shaft is rotatably connected to the second bearing on the partition.

7. The shaft eccentricity-compensated external control device for a miniature axial flow blood pump as described in claim 5, characterized in that, The channel cavity is provided with an output channel. One end of the output channel is fixed to the partition and the other end is connected to the conduit. The hard shaft of the driven member passes through the partition and the output channel and extends into the conduit. The output channel is connected to the infusion tube via the infusion channel.

8. The shaft eccentricity-compensated external control device for a miniature axial flow blood pump as described in claim 7, characterized in that, The infusion pipe is connected to the infusion assembly, which is used to connect to the flushing fluid supply device, wherein the infusion assembly includes an infusion valve.

9. The shaft eccentricity-compensated external control device for a miniature axial flow blood pump as described in claim 1, characterized in that, The miniature axial flow blood pump includes an inflow cage, one end of which is open to form an inflow inlet and is provided with a support frame, and the other end of which is provided with a base and is closed. The impeller is provided inside the inflow cage and is rotatably connected to a flexible shaft on the base. An outlet is provided on the side wall of the inflow cage.

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