Magnetic suspension double-center auxiliary device

Abstract

The magnetic suspension double-core auxiliary device comprises a pump body, and the pump body comprises a main pump inlet pipe, a main pump cavity, a communicating hole and an auxiliary pump cavity which are sequentially communicated; the rotor assembly comprises a shaft rod with one end arranged in the inner pipe, a first impeller set arranged in the main pump cavity, a connecting rod and a second impeller set arranged in the auxiliary pump cavity. The supporting assembly comprises a radial supporting structure which is arranged on the inner pipe and the shaft rod and acts on the shaft rod to achieve radial supporting of the rotor assembly and an axial supporting structure which is arranged in the partition cavity and acts on the second impeller set to achieve axial supporting of the rotor assembly; and the driving assembly is used for driving the rotor assembly to rotate and is arranged in the separation cavity. The length of a main pump inlet pipe is reduced, and the operation success rate is increased; mutual interference factors between the magnetic suspension device and the motor are reduced and eliminated; sufficient pump inlet sectional area is provided for high-efficiency design of pump fluid, a channel is kept smooth, and resistance is small.

Description

Technical Field

[0001] The present invention belongs to the technical field of cardiac assist devices, and in particular relates to a magnetically suspended dual-heart assist device. Background Art

[0002] There is currently no effective treatment for patients with advanced heart failure in the medical field. Only heart transplantation and artificial hearts are very effective surgical treatments. However, since heart transplantation has become a symbolic treatment technology due to a severe shortage of donors, artificial hearts have been given high hopes.

[0003] Artificial hearts and heart assist devices can be referred to as "blood pumps". Artificial hearts can be classified into total artificial hearts and auxiliary artificial hearts according to their functions. In recent years, heart assist devices represented by centrifugal or axial flow blood pumps with blades have become the mainstream of artificial heart development, such as HeartMate 2, HeartMate 3, HeartMate, Jarvik 2000 and Jarvik 2015 in the United States, which have been clinically used in tens of thousands of cases. However, these are all left ventricular assist device products. At present, there is no blood pump product with dual heart assist function like the total artificial heart on the market. Although there are foreign news reports of special cases of using two blood pumps to assist the left and right ventricles of patients with failure, this device requires the installation of two sets of blood pumps, which are large and invasive when implanted in the human body, and the external controller and battery also need to be configured with two systems, which will cause poor quality of life for patients. Therefore, there is an urgent need for a blood pump with dual heart assist function and small size in clinical practice.

[0004] The patent with application number 202311849700.3 discloses a "dual-heart assisted centrifugal blood pump", which includes a pump casing assembly, a rotor assembly, a supporting mechanism and a driving mechanism. The pump casing assembly is provided with a pump casing body, a partition arranged on the pump casing body and dividing it into two pump chambers, and two groups of pipe assemblies respectively connected to the two pump chambers; the rotor assembly is provided with a rotor inserted into two pump chambers and an inlet pipe and two impellers sleeved outside the rotor, and the two impellers are respectively placed in the two pump chambers; the supporting mechanism is provided with two groups of radial supporting mechanisms arranged at intervals on the rotor and an axial supporting mechanism arranged between the two impellers, and the radial supporting mechanism and the axial supporting mechanism work together to keep the rotor assembly in a stable suspended state; the driving mechanism can drive the rotor assembly to rotate, so that the two impellers respectively drive the blood circulation in the two pump chambers.

[0005] However, the existing structure has the following problems: 1. The motor and electromagnetic suspension are both set at the entrance of the left heart auxiliary. Since the main pump inlet pipe cannot be too thick, the outer diameter is generally controlled within φ22mm respectively. The drive motor and magnetic suspension mechanism must be placed in such a small space. The design is difficult in itself, and it is contradictory to the flow field design of the pump. From the perspective of pump design, the pump inlet flow channel needs to be unobstructed. Within a certain range, the larger the cross-sectional area of ​​the inlet flow channel, the better the pump efficiency. However, for the design of the motor, the smaller the air gap between the stator and the rotor, the higher the efficiency. The design of the magnetic suspension device is also the smaller the air gap, the better the effect. They all follow the principle of inverse square of the distance. The larger the air gap, the lower the efficiency exponentially. Therefore, the contradiction between the pump, motor and magnetic suspension is a thorny problem in the design.

[0006] 2. The rotor magnet and stator core of the motor must also maintain a sufficient distance from the magnetic suspension mechanism, especially the axial distance must be large enough, otherwise there will be serious interference and affect efficiency and safety. However, the length of the main pump inlet pipe is also limited, and generally must be controlled within 30mm, otherwise the pump port will be too long and will press against the myocardium, which may easily lead to surgical failure. Due to the limited radial and axial space at the pump inlet, the design of the motor and magnetic suspension is difficult. The motor must be small and needs to output a flow of 5L / min at a pressure of 100mmHg. The blood pump has high mechanical power consumption and low efficiency, which will cause the motor to heat up and destroy blood cells. For the magnetic suspension mechanism, the small size has poor rigidity and stability, and the blood pump has the risk of crashing, which will seriously affect the reliability and safety of the pump. Summary of the invention

[0007] In order to solve the problems that the motor and electromagnetic suspension of the existing dual-core auxiliary device are both arranged at the inlet pipe of the main pump, resulting in low smoothness of the pump inlet flow channel, affected motor design performance, and long pump inlet length affecting use, the present invention proposes a magnetic suspension dual-core auxiliary device.

[0008] The objective of the present invention is achieved through the following technical solutions: The present invention discloses a magnetic suspension dual-core auxiliary device, comprising: A pump body, the pump body comprising a main pump inlet pipe, a main pump chamber, a connecting hole and a secondary pump chamber connected in sequence, the main pump inlet pipe comprising an inner pipe and an outer pipe disposed outside the inner pipe, the main pump chamber is connected with a main pump outlet pipe, the secondary pump chamber is connected with an outer inlet pipe and a secondary pump outlet pipe, and the connecting hole is surrounded by a partition chamber and a perfusion hole connected with the connecting hole; A rotor assembly, the rotor assembly comprising a shaft with one end disposed in the inner tube, a first impeller assembly disposed in the main pump chamber, a connecting rod disposed in the communicating hole, and a second impeller assembly disposed in the auxiliary pump chamber, which are connected in sequence; A support assembly, the support assembly comprising a radial support structure disposed on the inner tube and the shaft rod and acting on the shaft rod to achieve radial support of the rotor assembly, and an axial support structure disposed in the compartment and acting on the second impeller assembly to achieve axial support of the rotor assembly; A driving assembly is used to drive the rotor assembly to rotate and is arranged in the compartment.

[0009] The beneficial effects of the present invention are: 1. The present invention arranges the driving assembly between the main pump chamber and the auxiliary pump chamber, and only arranges the radial support structure on the main pump inlet pipe, which not only reduces the length of the main pump inlet pipe and improves the success rate of the operation, but also reduces and eliminates the mutual interference factors between the magnetic suspension device and the motor.

[0010] 2. The main pump inlet pipe of the present invention adopts the structure of inner tube and outer tube to realize double flow channels. The radial support structure is arranged on the inner tube and the shaft rod, that is, it is arranged on both sides of the inner flow channel formed by the inner tube and the shaft rod. The radial air gap between the inner magnet and the outer magnet can be very small, and the gap of the outer flow channel is large, which can provide sufficient pump inlet cross-sectional area for the design needs of high efficiency of pump fluid, keep the channel smooth and the resistance small.

[0011] 3. The compartment of the present invention has a large volume, and the drive component has sufficient space, which further increases the power of the drive component, meets the required mechanical power consumption, and improves efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 It is a structural schematic diagram of the magnetic suspension dual-core auxiliary device of the present invention; Figure 2 It is a schematic diagram of the structure of the pump body; Figure 3 is a schematic diagram of the structure of the rotor assembly; Figure 4 It is a structural schematic diagram of an axially limited sliding bearing; Figure 5 is a structural schematic diagram of an inner sliding head; Figure 6 A schematic diagram of the state of the axial limit sliding bearing realizing the upper movement limit; Figure 7 is a structural schematic diagram of a radial support structure; Figure 8A structural schematic diagram of the main pump chamber; Fig. 9 It is a structural schematic diagram of the axial support structure; Fig.10 This is the force analysis diagram of the rotor assembly; Fig.11 It is a schematic diagram of the magnetic suspension dual-core auxiliary device of the present invention using the dual-core auxiliary function; Fig.12 It is a schematic diagram of the magnetic suspension dual-core auxiliary device of the present invention adopting a single-core auxiliary function.

[0014] Among them, the names of the reference numerals in the figure are: 1- pump body, 111- inner tube; 112, outer tube; 12- main pump chamber; 121- main pump outlet pipe; 13- communicating hole; 131- fixing groove; 14- auxiliary pump chamber; 141- outer inlet pipe; 142- auxiliary pump outlet pipe; 15- compartment chamber; 16- perfusion hole; 17- lead hole; 18- annular plate; 2-rotor assembly, 21-shaft rod; 22-connecting rod; 231-main upper cover; 232-main blade; 241-auxiliary upper cover; 242-auxiliary blade; 3- radial support structure, 31- first permanent magnet segment; 32- second permanent magnet segment; 33- third permanent magnet segment; 34- fourth permanent magnet segment; 35- fifth permanent magnet segment; 36- sixth permanent magnet segment; 4-axial support structure, 41-sensor; 42-iron core; 43-first winding; 44-second winding; 5-axial limit sliding bearing; 51-inner sliding head, 511-section structure; 52-upper limit ring; 521-second section structure; 53-lower limit ring; 531-third section structure; 61- regulating valve; 62- first connecting pipe; 63- second connecting pipe; 64- third connecting pipe; 65- second regulating valve; 7-Electronic control system; 8- Perfusion system. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0016] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0018] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0019] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use, or the positions or positional relationships commonly understood by those skilled in the art, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0020] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] The present invention provides a magnetic suspension double-core auxiliary device, comprising a pump body 1, a rotor assembly 2, a support assembly and a drive assembly.

[0022] Among them, refer to Figure 1 , 2As shown, the pump body 1 includes a main pump inlet pipe, a main pump chamber 12, a connecting hole 13 and an auxiliary pump chamber 14 which are connected in sequence, the main pump inlet pipe includes an inner tube 111 and an outer tube 112 arranged outside the inner tube, the main pump chamber 12 is connected to a main pump outlet pipe 121, the auxiliary pump chamber 14 is connected to an outer inlet pipe 141 and an auxiliary pump outlet pipe 142, and the connecting hole 13 is surrounded by a partition chamber 15 and an infusion hole 16 connected to the connecting hole 13.

[0023] Reference Figure 1 , 3 As shown, the rotor assembly 2 includes a shaft rod 21 with one end placed in the inner tube 111, a first impeller group placed in the main pump chamber 12, a connecting rod 22 placed in the connecting hole 13 and a second impeller group placed in the auxiliary pump chamber 14, which are connected in sequence.

[0024] Reference Figure 1 As shown, the support assembly includes a radial support structure arranged on the inner tube 111 and the shaft 21, acting on the shaft 21 to achieve radial support of the rotor assembly, and an axial support structure arranged in the compartment 15, acting on the second impeller group to achieve axial support of the rotor assembly.

[0025] Reference Figure 1 As shown, the driving assembly is used to drive the rotor assembly 2 to rotate and is disposed in the compartment 15 .

[0026] With the above structure, a set of driving components and rotor components simultaneously drive the blood in the two pump chambers to circulate, thereby realizing the dual-heart assist function and avoiding the disadvantages caused by the existing implantation of two blood pumps.

[0027] With the above structure, the driving assembly is arranged between the main pump chamber and the auxiliary pump chamber, and only the radial support structure is arranged on the main pump inlet pipe, which not only reduces the length of the main pump inlet pipe and improves the success rate of the operation; and the main pump inlet pipe adopts the structure of the inner tube 111 and the outer tube to realize the double flow channel, and the radial support structure is arranged on the inner tube 111 and the shaft rod 21, that is, it is arranged on both sides of the inner flow channel formed by the inner tube 111 and the shaft rod 21. The radial air gap between the inner magnet and the outer magnet can be very small, and the gap of the outer flow channel is large, which can provide sufficient pump inlet cross-sectional area for the design needs of high efficiency of the pump fluid, keep the channel smooth and the resistance small.

[0028] By adopting the above structure, the drive assembly is arranged in the compartment, separated from the radial support structure with sufficient spacing, which not only does not affect the fluid efficiency of the pump, but also eliminates the mutual interference factors between the magnetic levitation device and the motor, which is beneficial to improving the mechanical efficiency, stability and safety of the blood pump.

[0029] With the above structure, the compartment volume is large, and the drive component has sufficient space, which further increases the power of the drive component, meets the required mechanical power consumption, and improves efficiency.

[0030] Specifically, there are many ways to implement the first impeller group and the second impeller group of the rotor assembly 2. For example, the patent with application number 202311849700.3 discloses a structure of a "double-heart auxiliary centrifugal blood pump", that is, the upper and lower ends of the blades are closed and a cover is provided. However, with the above structure, the impeller is subjected to a large passive axial upward hydraulic pressure thrust. For this reason, preferably, the rotor assembly 2 adopts the following Figure 3 The structure shown, that is, the first impeller group includes a main upper cover 231 and a main blade 232, and the second impeller group includes an auxiliary upper cover 241 and an auxiliary blade 242. With this structure, the lower ends of the first impeller group and the second impeller group are open, and no cover is provided, which can reduce the passive axial upward hydraulic pressure thrust of the two impeller groups.

[0031] The above-mentioned rotor assembly 2 structure, i.e., a single-side open design, can be used to generate a single-direction hydraulic pressure in the axial direction. Figure 1 The direction shown is downward, which is used to counteract the strong suction force of the stator core on the rotor magnet. The electromagnet can also determine the axial position of the impeller and the direction and magnitude of the axial force at any time through the detection of the sensor. According to the needs, an axial force in a different direction is generated to balance the axial force, so that the dynamic axial resultant force is zero or approaches zero, thereby achieving a steady-state axial suspension effect.

[0032] The main upper cover 231 and the auxiliary upper cover 241 are coaxially arranged and parallel to each other.

[0033] In the above structure, further, Figure 8 As shown, an annular plate 18 is provided in the main pump chamber 12, and the annular plate 18 is placed between the main blade 232 and the bottom of the main pump chamber 12, and the distance between the annular plate 18 and the bottom of the main pump chamber 12 gradually increases from the outer diameter to the inner diameter. That is, the annular plate 18 is a concave structure as a whole, and forms a backflow channel with the bottom of the main pump chamber 12. The inlet of the backflow channel is the gap between the annular plate 18 and the side wall of the main pump chamber 12, and the outlet of the backflow channel is the gap between the annular plate 18 and the rotor assembly 2. The pressure at the inlet of the backflow channel is greater than the pressure at the outlet of the middle backflow channel. The secondary backflow driven by the pressure difference can have a good flushing effect on the sliding bearing port to avoid thrombosis.

[0034] In the above structure, the outer diameter of the main blade 232 is greater than the outer diameter of the auxiliary blade 242. The outer diameter of the main blade 232 is large to maintain the high fluid efficiency, and the outer diameter of the auxiliary blade 242 is small so that the auxiliary pump pressure is always kept below 30 mmHg, but the auxiliary flow can be ensured to avoid pulmonary hypertension during right heart assistance.

[0035] In the above structure, the driving assembly includes a magnetic steel to establish and maintain a magnetic field, and the main upper cover 231 can be directly used as the magnetic steel of the driving assembly. At this time, the main upper cover 231 adopts a strong permanent magnetic material of 52-58 type in neodymium iron boron.

[0036] In order to increase the weight and energy density of the built-in rotor magnets, thereby improving the efficiency of the motor and increasing the axial downward hydraulic pressure and the axial suspension performance of the rotor impeller, the outer diameter of the main upper cover 231 is smaller than the outer diameter of the auxiliary upper cover 241.

[0037] The axial support structure 4 realizes the axial suspension balance of the rotor assembly 2. Fig. 9 As shown, it includes a sensor 41 for detecting the axial movement of the rotor assembly 2 , a plurality of iron cores 42 evenly arranged around the connecting rod 22 , and a first winding 43 wound on the iron cores 42 .

[0038] The sensor can be implemented as a position sensor, a distance sensor, etc.

[0039] There are six iron cores 42 and one end of the iron cores 42 is in a plate shape.

[0040] In order to achieve stable detection of the rotor assembly 2 at the same time, there are multiple sensors 41 , which are evenly arranged around the connecting rod 22 .

[0041] There are many ways to implement the drive assembly. In order to simplify the structure, the drive assembly shares some components with the axial support structure 4 , that is, the drive assembly includes a second winding 44 wound on the iron core 42 , that is, a shared iron core 42 .

[0042] By adopting the above-mentioned axial support structure 4 and driving structure, when the whole device is working, the main upper cover 231 and the upper cavity surface of the main pump chamber 12 form a main return flow channel, and the auxiliary upper cover 241 and the upper cavity surface of the auxiliary pump chamber 14 form an auxiliary return flow channel. Due to the backflow caused by the pressure difference, both flow channels will generate two hydraulic pressures, namely the main hydraulic pressure F2 and the auxiliary hydraulic pressure F3. The direction of the two forces is axially downward, and the magnitude of the two forces is positively correlated with the rotation speed of the impeller group and the pressure inside the pump. When the whole device is working at high speed, it will be affected by multiple axial forces, which can be divided into weak axial force and strong axial force. The weak axial force mainly includes the axial component of the gravity of the rotor assembly, the liquid impulse of the main pump inlet pipe, the liquid buoyancy of the impeller group, and the axial force caused by the slight offset of the radial magnetic suspension group. These are weak influencing factors and can be ignored in the analysis. Fig.10As shown, the strong axial force mainly includes four axial forces: magnetic attraction force F1, main hydraulic pressure F2, auxiliary hydraulic pressure F3, and active electromagnetic force F4; among them, F1 is the suction force generated by the rotor magnet of the motor on the stator core 42, the direction of the force is axially upward, and the magnitude of the force is positively correlated with the mass and distance between the two. Since the peripheral pressure of the main blade 232 is 5-10 times higher than the peripheral pressure of the auxiliary blade 242, F2 is much larger than F3. Since the axial upward F1 has a large value, and the downward hydraulic pressures F1 and F2 have large value changes due to the uncertain speed, when the rotor assembly is running at a low speed, the combined force of F2 and F3 is not enough to offset F1. When the rotor assembly has a slight axial offset, including upward offset of the impeller at low speed and up / down offset when impacted, the sensor will detect the position of the rotor assembly. After signal amplification, feedback and control, an active electromagnetic force F4 will be generated to pull the rotor impeller back to the equilibrium position. The combined force of F2, F3 and F4 is sufficient to balance F1 and keep the total axial force at 0, so that the rotor assembly is always in an axial suspension state.

[0043] Generally, the components consisting of the iron core 42, the first winding 43, and the second winding 44 are set in 6 groups, and the feeding connection mode can be divided into two groups of 3+3. In normal operation, the active electromagnetic force F4 is an auxiliary force, the value should not be very large, the direction can be downward or upward, and generally intermittent operation is sufficient, and the power consumption and heat generation are both small.

[0044] Under the action of the support assembly, the rotor assembly maintains a suspended equilibrium state. In order to protect the rotor assembly and avoid support and protection during startup, sudden changes and emergency conditions, an axial limit sliding bearing 5 is also included. Figures 4 to 6 As shown, the axial limiting sliding bearing includes an upper limiting ring 52 and a lower limiting ring 53 both fixed on the connecting hole 13 , and an inner sliding head 51 fixed on the connecting rod 22 and placed between the upper limiting ring 52 and the lower limiting ring 53 .

[0045] The inner sliding head 51 is provided with a first section structure 511 at both ends, and the upper limit ring 52 and the lower limit ring 53 are respectively provided with a second section structure 521 and a third section structure 531 parallel to the first section structure 511 at the corresponding positions of the first section structure 511, and the injection hole 16 is arranged between the second section structure 521 and the third section structure 531.

[0046] In order to enhance the stability of the upper limiting ring 52 and the lower limiting ring 53, a fixing groove may be provided on the side wall of the connecting hole to realize the installation and fixation of the limiting ring.

[0047] During normal operation, there are gaps between the first section structure of the inner sliding head 51 and the second section structure 521 and the third section structure 531, and there is no contact. The rotor assembly is in a suspended state and will not wear. The perfusion system 8 can provide anticoagulant fluid for lubrication through the perfusion hole 16.

[0048] When the rotor assembly moves up and down, the amount of up and down movement can be limited to prevent the rotor assembly from hitting or scratching the pump chamber, causing safety accidents, and avoiding the occurrence of thrombosis and hemolysis complications. While achieving upper and lower limits, radial limits can also be achieved to prevent mechanical wear and damage caused by failures and accidents.

[0049] The inner slider 51 can be made of hard materials such as diamond, silicon carbide, silicon nitride, boron carbide, etc.; the upper limit ring 52 and the lower limit ring 53 can be made of aluminum oxide, zirconium oxide, or tri-yttrium zirconium oxide composite ceramic material.

[0050] There are many ways to implement the radial support structure 3, such as using the structure of a "double-heart auxiliary centrifugal blood pump" disclosed in patent application number 202311849700.3. In order to improve the stability of the radial support, it is preferred to use Figure 7 The structure shown, i.e., the radial support structure 3 comprises an outer permanent magnetic ring arranged on the inner tube 111 and an inner permanent magnetic ring arranged on the shaft 21; The outer permanent magnet ring includes a first permanent magnet segment 31, a second permanent magnet segment 32 and a third permanent magnet segment 33 arranged in sequence, wherein the inner diameter and outer diameter of the first permanent magnet segment 31 and the third permanent magnet segment 33 have opposite polarities, and the inner diameter of the first permanent magnet segment 31 and the inner diameter of the third permanent magnet segment 33 have opposite polarities, The inner permanent magnet ring comprises a fourth permanent magnet segment 34, a fifth permanent magnet segment 35 and a sixth permanent magnet segment 36 which are arranged in sequence. The inner diameter and outer diameter polarities of the fourth permanent magnet segment 34 and the sixth permanent magnet segment 36 are opposite. The polarity of the outer diameter of the fourth permanent magnet segment 34 is the same as the polarity of the inner diameter of the first permanent magnet segment 31. The polarity of the outer diameter of the sixth permanent magnet segment 36 is the same as the polarity of the inner diameter of the third permanent magnet segment 33. The polarities of the second permanent magnet segment 32 and the fifth permanent magnet segment 35 are different at two ends, and the polarities of the second permanent magnet segment 32 and the fifth permanent magnet segment 35 are the same at the same end.

[0051] With the above structure, the outer permanent magnet ring includes the first permanent magnet segment 31, the second permanent magnet segment 32 and the third permanent magnet segment 33 arranged in sequence, and the upper and lower permanent magnet ring segments constitute radiation magnetization, with one polarity inside and outside in the radial direction; the second permanent magnet segment 32 is axially magnetized, that is, the polarities at both ends are different; the upper, middle and lower three magnetic rings are stacked together and are seen as the same magnetic poles sticking together on the inside. The inner permanent magnet ring includes the fourth permanent magnet segment 34, the fifth permanent magnet segment 35 and the sixth permanent magnet segment 36 arranged in sequence, and the upper and lower two permanent magnet ring segments constitute radiation magnetization, with one polarity inside and outside in the radial direction; the fifth permanent magnet segment 35 is axially magnetized, and the upper, middle and lower three magnetic rings are stacked together and are seen as the same magnetic poles sticking together on the outside. The radial magnetic fields of the outer permanent magnet ring and the inner permanent magnet ring are both opposite to each other in the same magnetic field, and radial repulsion is generated by repulsion; when the axial alignment is maintained, the inner and outer magnetic groups can achieve radial magnetic suspension.

[0052] With the above structure, in order to further improve the radial stability, there are two groups of radial support structures 3 and the two groups of radial support structures 3 are coaxially arranged.

[0053] When installing the two sets of radial support structures 3 at the inlet pipe of the main pump, they need to be separated as much as possible, firstly to avoid magnetic interference, and secondly to make the radial suspension more stable. Since two points determine a line, if the two sets of radial support structures 3 are too close, the rotor will easily deflect radially. Installing the two sets of radial support structures 3 at a distance can also make the center of gravity of the rotor impeller more stable and the radial suspension effect better. The two sets of radial support structures 3 are coaxially arranged and aligned in the axial direction, so that the rotor assembly can maintain radial magnetic suspension, and coupled with the gyroscopic fixed axis effect during rotation, a good radial suspension effect can be obtained. Taking into account the length of the inlet pipe of the main pump and the radial stability, it is preferred that the distance between the two sets of radial support structures 3 is greater than or equal to 10 mm and less than 15 mm.

[0054] For example, if the axial direction of the shaft is defined as the up and down direction, such as Figure 4 As shown, the polarity of the outer diameter surface of the first permanent magnet segment 31 is S pole, and the polarity of the inner diameter surface is N pole; the polarity of the upper end and the lower end of the second permanent magnet segment 32 are N pole and S pole respectively; the polarity of the outer diameter surface of the third permanent magnet segment 33 is N pole, and the polarity of the inner diameter surface is S pole. The polarity of the outer diameter surface of the fourth permanent magnet segment 34 is N pole, and the polarity of the inner diameter surface is S pole; the polarity of the upper end and the lower end of the fifth permanent magnet segment 35 are N pole and S pole respectively; the polarity of the outer diameter surface of the sixth permanent magnet segment 36 is S pole, and the polarity of the inner diameter surface is N pole. Such an arrangement and combination can be used to make the relative positions of the outer permanent magnet ring and the inner permanent magnet ring produce combined and enhanced N and S, and the radially same magnetic poles are opposite. The outer diameter surface of the outer permanent magnet ring and the center of the inner permanent magnet ring are magnetically short-circuited, making the magnetism extremely weak; such an arrangement can greatly improve the energy density and magnetic suspension effect of permanent magnetic suspension.

[0055] The polarities of the two groups of radial support structures 3 are symmetrically arranged about the vertical line, that is, one group of radial support structures 3 is flipped and inverted by the other group. The two groups of radial support structures 3 have like magnetic poles facing each other and are spaced apart, so the mutual magnetic interference is small.

[0056] The radial support structure 3 adopts 52-58 type strong permanent magnetic material of neodymium iron boron.

[0057] The external perfusion system delivers heparin-like anticoagulant to the cavity of the pump body 1 through the perfusion hole 16. A lead hole can be provided on the pump body 1 for external connection of the delivery pipe of the perfusion system and the axial support structure 4 and the control line of the drive assembly. The heparin-like anticoagulant delivered by the perfusion system can flush the bearing opening of the axial limit sliding bearing through the perfusion hole 16, playing the role of dynamic sealing of the bearing. The anticoagulant can anticoagulate blood and prevent the formation of thrombus; the perfusion liquid can also play a role of lubrication for the bearing.

[0058] The heparin-based anticoagulant is delivered through the external perfusion system 8, which can play an anticoagulant role, especially for dead angles and dead cavities with small gaps, such as the fitting clearance of mechanical bearings, which can effectively prevent thrombosis and even embolism; and through the internal pressure perfusion and flushing of the narrow space of the bearing, it plays a dynamic sealing role for the bearing opening, which can prevent blood from infiltrating, avoiding the formation of thrombosis and hemolysis caused by mechanical grinding; the anticoagulant can lubricate the bearing and increase the mechanical life of the bearing and the blood pump; the perfusion system has an alarm prompt. In addition to requiring the patient to replenish the anticoagulant in time according to the prompt, the patient no longer needs to take oral anticoagulants, and there is no need to worry about the patient forgetting or not taking the anticoagulant on time, which will cause the formation of thrombosis in the blood pump.

[0059] The above-mentioned magnetic suspension dual heart assist device not only has the dual heart assist function, but also only needs to be installed with the main pump, and the main pump chamber 12 can perform left heart assist.

[0060] For patients with double heart failure, refer to Fig.11 , through thoracotomy, the magnetic suspension dual heart assist device is installed in the patient's chest. Among them, the main pump inlet pipe is directly inserted into the left ventricle and fixed by suture ring; the main pump outlet pipe 121 is connected to the first connecting pipe 62 and connected to the aortic opening, and the first connecting pipe is provided with a first regulating valve 61 to achieve flow regulation. The external inlet pipe 141 is connected to the second connecting pipe 63 and inserted into the right ventricle; the auxiliary pump outlet pipe 142 is connected to the third connecting pipe 64 and connected to the pulmonary artery opening, and the third connecting pipe 64 is provided with a second regulating valve 65 to achieve flow regulation. The signal line of the winding coil is led out of the patient's body through the lead hole, and the external electric control system 7 is driven by the motor to drag the rotor assembly to run, and the centrifugal force is used to promote the two groups of blood circulation of the systemic circulation and the pulmonary circulation, so as to play the role of dual heart assist.

[0061] With this structure, a blood pump can be turned off at any time. If the function of one of the ventricles is restored, the doctor decides that its auxiliary flow needs to be adjusted to an extremely low level or even turned off, and only needs to be operated by external electrical control. If the left heart is restored, the first regulating valve 61 is adjusted to reduce the diameter of the main pump outlet pipe to reduce the flow, and the flow is turned off by closing it. If the right heart is restored, the second regulating valve 65 is adjusted to reduce the diameter of the auxiliary pump outlet pipe to reduce the flow, and the flow is turned off by closing it. However, it is generally not recommended to close the valve, and a smaller diameter is still left, and the flow is adjusted to an extremely low level; the motor still rotates and works to maintain the required flow assistance to the other failing ventricle. Because of the effect of the anticoagulant solution, the blood inside the closed auxiliary pump and the connected ventricular inlet will not cause coagulation and thrombosis in the pump; when the patient has heart failure again and needs to restart the auxiliary function of the closed pump, it is only necessary to increase the outlet regulating valve, and the operation is very convenient; because of the regulating valve, the left heart assistance and the right heart assistance work well together, and the flow matching is adjustable.

[0062] When only the main pump is installed, Fig.12 As shown, the installation method of the main pump inlet pipe and the main pump outlet pipe 121 is the same as that of the patient with double heart failure, except that the connecting pipe is directly used to connect the external inlet pipe 141 and the auxiliary pump outlet pipe 142. That is, the auxiliary function of the auxiliary pump chamber is abolished. Although the second impeller group is still rotating, it is only the anticoagulant solution filled in the pump that circulates automatically, and there is no need to worry about complications such as thrombosis.

[0063] With the above structure, the main upper cover 231, i.e., the magnet, is in the auxiliary pump cavity. Since the auxiliary pump cavity has a large enough and spare space, the rotor magnet can be designed to be large enough according to the design requirements of the motor, and the magnetic air gap can be very small, which can not only improve the efficiency of the motor but also does not affect the fluid efficiency of the auxiliary pump. Since the motor has a high power conversion efficiency and generates little heat, the damage to blood cells and complications such as pyrogenic hemolysis are less, thereby improving the safety of the blood pump.

[0064] The structure of this solution can not only realize dual-heart assistance with one pump, but also work with only one blood pump, such as only one left heart assistance, which is convenient for clinical surgical installation and can also reduce the manufacturing cost and sales cost of the blood pump. Its structure is novel, reasonable and simple, which can greatly improve the availability of the blood pump; the blood pump has a small pump volume and light weight, which can reduce the invasiveness of the blood pump implantation.

[0065] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A magnetically suspended dual-core auxiliary device, characterized in that: include: A pump body (1), the pump body (1) comprising a main pump inlet pipe, a main pump chamber (12), a communicating hole (13) and a secondary pump chamber (14) connected in sequence, the main pump inlet pipe comprising an inner pipe (111) and an outer pipe (112) disposed outside the inner pipe, the main pump chamber (12) being connected to a main pump outlet pipe (121), the secondary pump chamber (14) being connected to an outer inlet pipe (141) and a secondary pump outlet pipe (142), the communicating hole (13) being provided with a partition chamber (15) and a perfusion hole (16) connected to the communicating hole (13) around it; A rotor assembly (2), the rotor assembly (2) comprising a shaft (21) with one end disposed in the inner tube (111), a first impeller assembly disposed in the main pump chamber (12), a connecting rod (22) disposed in the communicating hole (13), and a second impeller assembly disposed in the auxiliary pump chamber (14), which are connected in sequence; A support assembly, the support assembly comprising a radial support structure (3) arranged on the inner tube (111) and the shaft (21) and acting on the shaft (21) to achieve radial support of the rotor assembly, and an axial support structure (4) arranged in the compartment (15) and acting on the second impeller assembly to achieve axial support of the rotor assembly; A drive assembly, the drive assembly is used to drive the rotor assembly (2) to rotate and is arranged in the compartment (15).

2. A magnetically suspended dual-core auxiliary device according to claim 1, characterized in that: The first impeller assembly comprises a main upper cover (231) and main blades (232). The second impeller assembly comprises an auxiliary upper cover (241) and auxiliary blades (242).

3. The magnetic suspension dual-core auxiliary device according to claim 2, characterized in that: The outer diameter of the main blade (232) is greater than the outer diameter of the auxiliary blade (242); The main upper cover (231) is a magnetic steel of the driving component, and the outer diameter of the main upper cover (231) is smaller than the outer diameter of the auxiliary upper cover (241).

4. The magnetic suspension dual-core auxiliary device according to claim 2, characterized in that: An annular plate (18) is arranged in the main pump chamber (12); the annular plate (18) is placed between the main blade (232) and the bottom of the main pump chamber (12); the distance between the annular plate (18) and the bottom of the main pump chamber (12) gradually increases from the outer diameter to the inner diameter.

5. The magnetically suspended dual-core auxiliary device according to claim 3, characterized in that: The axial support structure (4) comprises a sensor (41) for detecting the axial movement of the rotor assembly (2), a plurality of iron cores (42) evenly arranged around the connecting rod (22), and a first winding (43) wound on the iron cores (42); The drive assembly includes a second winding (44) wound around the core (42).

6. The magnetically suspended dual-core auxiliary device according to claim 1, characterized in that: It also includes an axial limit sliding bearing (5), which includes an upper limit ring (52) and a lower limit ring (53) both fixed on the connecting hole (13), and an inner sliding head (51) fixed on the connecting rod (22) and disposed between the upper limit ring (52) and the lower limit ring (53).

7. The magnetic suspension dual-core auxiliary device according to claim 6, characterized in that: Both ends of the inner sliding head (51) are provided with a first section structure (511); the upper limit ring (52) and the lower limit ring (53) are provided with a second section structure (521) and a third section structure (531) parallel to the first section structure (511) at positions corresponding to the first section structure (511); and the injection hole (16) is provided between the second section structure (521) and the third section structure (531).

8. The magnetically suspended dual-core auxiliary device according to claim 1, characterized in that: The radial support structure (3) comprises an outer permanent magnetic ring arranged on the inner tube (111) and an inner permanent magnetic ring arranged on the shaft (21); The outer permanent magnetic ring comprises a first permanent magnetic segment (31), a second permanent magnetic segment (32) and a third permanent magnetic segment (33) which are arranged in sequence, the inner diameter and outer diameter of the first permanent magnetic segment (31) and the third permanent magnetic segment (33) having opposite polarities, and the inner diameter of the first permanent magnetic segment (31) and the inner diameter of the third permanent magnetic segment (33) having opposite polarities, The inner permanent magnet ring comprises a fourth permanent magnet segment (34), a fifth permanent magnet segment (35) and a sixth permanent magnet segment (36) which are arranged in sequence, the inner diameter and outer diameter polarities of the fourth permanent magnet segment (34) and the sixth permanent magnet segment (36) being opposite, the polarity of the outer diameter of the fourth permanent magnet segment (34) being the same as the polarity of the inner diameter of the first permanent magnet segment (31), and the polarity of the outer diameter of the sixth permanent magnet segment (36) being the same as the polarity of the inner diameter of the third permanent magnet segment (33); The polarities of the two ends of the second permanent magnet segment (32) and the fifth permanent magnet segment (35) are different, and the polarities of the same ends of the second permanent magnet segment (32) and the fifth permanent magnet segment (35) are the same.

9. The magnetically suspended dual-core auxiliary device according to claim 8, characterized in that: The radial support structures (3) include two groups, and the two groups of radial support structures (3) are coaxially arranged.

10. The magnetically suspended dual-core auxiliary device according to claim 9, characterized in that: The polarities of the two groups of radial support structures (3) are arranged symmetrically about their perpendicular lines.

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