Blood pump

Abstract

The blood pump comprises an impeller and a driving unit which are axially arranged, the near end of the impeller is connected with a magnet, the driving unit and the magnet form an end face magnetic coupling driving structure, the far end of the driving unit is provided with a near-end supporting assembly, and the near-end supporting assembly is connected with the near-end supporting assembly. The near-end supporting assembly comprises a fixed shaft tube and a bearing seat, the fixed shaft tube and the bearing seat are in circumferential limiting and axial sliding fit, the near end of the impeller is rotatably supported in the bearing seat, lubricating oil is arranged in a cavity between the fixed shaft tube and the near end of the bearing seat, and an oil guide hole penetrating through the two ends of the bearing seat is formed in the bearing seat. Lubricating oil is provided for the abutting face of the impeller shaft and the bearing seat, the problem that resistance is large when the blood pump is initially started is solved, and rotation can be effectively assisted. Meanwhile, lubricating oil can be provided only in the working state, leakage and long-term use of the lubricating oil are prevented, the supply amount of the lubricating oil can be automatically adjusted, and the purpose of self-adaptive supply is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a blood pump. BACKGROUND

[0002] The blood pump, also known as a mechanical blood circulation support device or a heart pump assembly, can be introduced into the heart and can be configured to assist or replace the natural heart function by circulating or continuously pumping blood to provide blood flow power support for cardiogenic shock and acute heart failure. For the magnetic coupling driven blood pump, since it is worked in the human body by vascular intervention, the performance of the connecting shaft determines whether the blood pump can normally pump blood, and the debris generated by wear will also cause complications and even endanger life, so the requirements for low wear, stable operation and service life are higher. SUMMARY

[0003] The present application provides a blood pump capable of reducing wear and having self-adaptive function.

[0004] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows: a blood pump comprising an impeller and a driving unit arranged axially, a magnet connected to the proximal end of the impeller, and an end face magnetic coupling driving structure formed by the driving unit and the magnet, a proximal end support assembly provided at the distal end of the driving unit, the proximal end support assembly comprising a fixed shaft tube and a bearing seat and being in circumferential limiting and axial sliding fit, the proximal end of the impeller being rotatably supported in the bearing seat, a lubricating oil being provided in the chamber between the fixed shaft tube and the proximal end of the bearing seat, and an oil guide hole being provided in the bearing seat and penetrating through both ends thereof.

[0005] Further, the bearing seat comprises a small-diameter proximal section and a large-diameter distal section, the inner diameter of the small-diameter proximal section matches the inner diameter of the fixed shaft tube and forms a sealing fit, and a groove is provided on the distal end face of the large-diameter distal section, the proximal end of the impeller shaft being placed in the groove to form axial limiting, radial limiting and circumferential rotating fit.

[0006] Further, the driving unit comprises a housing, a plurality of magnetic columns are provided in the housing at intervals, the proximal ends of the plurality of magnetic columns are inserted into the mounting holes of the stator seat to form fixed connection, the plurality of magnetic columns are uniformly and interval arranged circumferentially and located on the circumferential surface of the same cylinder, the center line of the cylinder is collinear with the rotation axis of the impeller, the coil winding is wound on the outer periphery of the magnetic column to form an electromagnet structure, when the coil winding is energized, the magnetic attraction force between the magnetic column and the magnet drives the proximal end of the impeller, and the rotating magnetic field generated by the electromagnet structure drives the impeller to rotate.

[0007] Further, the fixed shaft tube is located at the center of the distal end of the shell, and includes a distal end extension protruding towards the distal end and a proximal end extension protruding towards the inner cavity of the shell, the lubricating oil is arranged in the inner cavity of the proximal end extension, the inner cavity of the distal end extension is provided with a guide groove, and the guide ribs arranged on the outer periphery of the small diameter proximal section are in axial guide cooperation with the guide groove.

[0008] Further, the hole core of the oil guide hole coincides with the shaft core of the bearing seat, the distal end of the oil guide hole is located at the groove bottom of the groove, the oil guide hole is provided with only one, and the inner diameter of the oil guide hole is 0.15-0.5 mm.

[0009] Further, the chamber between the fixed shaft tube and the proximal end of the bearing seat is provided with an elastic element, and the lubricating oil is soaked in the elastic element.

[0010] Further, the proximal end of the impeller shaft is a hemispherical head, the groove is also a shape matched with the hemispherical head, and the depth L of the groove is greater than the radius R of the hemispherical head.

[0011] Further, the impeller includes a hub and blades arranged on the outer periphery thereof, the impeller shaft passes through and is fixed in the through hole axially opened in the hub, the proximal end of the impeller shaft extends into the inner cavity of the magnet and abuts against the distal end of the bearing seat to form axial limiting, radial limiting and circumferential rotating cooperation.

[0012] Further, the outer periphery of the impeller is provided with a blood cage, the proximal end of the blood cage is welded and fixed with the distal end of the shell, the blood cage is in the shape of a circular tube as a whole, the distal end of the circular tube forms a blood inlet, a plurality of blood outlets are arranged on the proximal side outer peripheral wall of the blood cage along the circumferential direction thereof, a limiting ring for supporting the distal end of the impeller shaft is arranged at the tube opening of the circular tube, and the two form radial limiting, axial sliding and circumferential rotating cooperation.

[0013] Further, the lubricating oil is medical silicon oil.

[0014] In the above scheme, by providing lubricating oil to the abutting surface of the impeller shaft and the bearing seat, the problem of large resistance during initial start of the blood pump is solved, and rotation can be effectively assisted. In addition to being able to provide lubricating oil only in the working state, prevent leakage of lubricating oil and long-term use, the amount of lubricating oil can also be automatically adjusted to achieve the purpose of self-adaptive supply. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 FIG. 1 is a structural schematic diagram of the blood pump; Figure 2 FIG. 2 is a partial cross-sectional view of the blood pump; Figure 1 FIG. 3 is a full cross-sectional view of the blood pump; Figure 3 Figure 1 Figure 4 Figure 3 ​​​partly enlarged schematic view of the blood pump; Figure 5 is a cross-sectional view of the housing and proximal support assembly; Figure 6 is a perspective view of the housing and proximal support assembly.

[0016] In the figure: 10 - impeller, 11 - hub, 12 - blade, 13 - impeller shaft, 131 - half ball head, 20 - drive unit, 21 - fixed shaft tube, 211 - proximal extension, 212 - distal extension, 213 - guide groove, 22 - bearing seat, 221 - oil guide hole, 222 - small-diameter proximal section, 223 - large-diameter distal section, 224 - groove, 225 - guide rib, 23 - housing, 24 - magnetic column, 25 - stator seat, 26 - winding coil, 30 - magnet, 40 - blood cage, 41 - blood outlet, 42 - limiting ring, A - lubricating oil. DETAILED DESCRIPTION

[0017] For ease of understanding, first we define the position: "proximal", "proximal" refers to the side close to the operator / doctor, "distal", "distal" refers to the side away from the operator / doctor, i.e. the side close to the heart, and the following will be combined with the accompanying Figures 1-6 The application is further described in detail.

[0018] Referring to Figures 1-4 As shown in the figure, a blood pump comprises an axially arranged impeller 10 and a drive unit 20, the proximal end of the impeller 10 is connected with a magnet 30, the drive unit 20 and the magnet 30 form an end face magnetic coupling driving structure, the distal end of the drive unit 20 is provided with a proximal support assembly, the proximal support assembly comprises a fixed shaft tube 21 and a bearing seat 22 and the two form a circumferential limiting and axial sliding fit, the proximal end of the impeller 10 is rotatably supported in the bearing seat 22, the chamber between the fixed shaft tube 21 and the proximal end of the bearing seat 22 is provided with lubricating oil A, the bearing seat 22 is provided with an oil guide hole 221 penetrating through both ends thereof.

[0019] The end face magnetic coupling driving structure is a non-contact transmission structure for realizing power transmission through magnetic field, the core of which is that the active end and the driven end are respectively provided with permanent magnets or electromagnets, through the principle of opposite poles attracting or same poles repelling, a magnetic force coupling is formed between the end faces, so as to realize the transmission of torque or force. This non-contact transmission avoids friction and wear problems, prolongs the service life of the blood pump; at the same time, the non-contact structure also makes the rotating shaft of the impeller 10 not inserted into the inside of the drive unit 20, so that the drive unit 20 can be provided in a sealed structure form to prevent blood from entering and reduce the formation of thrombus, thereby improving the safety performance of the entire blood pump. In addition, the entire structure is compact, the intervention trauma is small, and the safety performance is high, which is particularly suitable for long-term auxiliary (even up to one year) demand of the interventional blood pump.

[0020] Specific to the present application, the magnetic attraction between the drive unit 20 and the magnet 10 makes the proximal end of the impeller 10 tightly pressed in the bearing seat 22, when the drive unit 20 drives the impeller 10 to rotate, the bearing seat 22 has a tendency to move towards the proximal end due to the pressure, that is, the bearing seat 22 moves towards the proximal end, therefore the pressure in the chamber between the fixed shaft tube 21 and the proximal end of the bearing seat 22 increases, the internal lubricating oil A will enter the end face of the bearing seat 22 and the proximal end of the impeller 10 through the oil guide hole 221, thereby lubricating the end face and reducing wear. This way of providing lubricating oil A slowly and gradually prevents too much lubricating oil A from affecting blood components, and a small amount of lubricating oil A can provide long-term lubrication for the friction surface, which is suitable for such a year-long auxiliary blood pump.

[0021] Further, referring to Figure 5 、 Figure 6 The bearing seat 22 includes a small-diameter proximal section 222 and a large-diameter distal section 223, the inner diameter of the small-diameter proximal section 222 matches the inner diameter of the fixed shaft tube 21 and forms a sealing fit, ensuring that the lubricating oil A can only overflow from the middle oil guide hole 221 and cannot flow out from the gap between the small-diameter proximal section 222 and the fixed shaft tube 21. The distal end face of the large-diameter distal section 223 is provided with a groove 224, and the proximal end of the impeller shaft 13 is placed in the groove 224 to form an axial limiting, radial limiting and circumferential rotating fit. In addition, a sealing structure such as a rubber ring + wear-resistant ring (such as PTFE) combined sealing can be provided between the small-diameter proximal section 222 and the inner cavity of the fixed shaft tube 21, which can provide sufficient sealing to prevent leakage of lubricating oil A, and can reduce friction through the wear-resistant ring, which is suitable for such high-pressure and low-speed sliding requirements.

[0022] As a preferred scheme of the present application, the driving unit 20 comprises a shell 23, a plurality of magnetic columns 24 are arranged in the shell 23, the proximal ends of the plurality of magnetic columns 24 are inserted into the mounting holes 251 of the stator base 25 to form fixed connection, the plurality of magnetic columns 24 are uniformly and spaced arranged in the circumferential surface of a cylinder, the center line of the cylinder is collinear with the rotation axis of the impeller 10, the coil winding 26 is wound on the outer periphery of the magnetic column 24 to form an electromagnet structure, when the coil winding 26 is electrified, the magnetic attraction force between the magnetic column 24 and the magnet 30 drives the impeller 10 to move towards the proximal end, and the rotating magnetic field generated by the electromagnet structure drives the impeller 10 to rotate. The electromagnet is a device for generating magnetic force by magnetizing the iron core by the magnetic effect of electric current, in the present application, when the coil winding 26 is electrified, the magnetic column 24 generates magnetic attraction to the magnet 30 to move towards the proximal end, when the electric current is cut off, the magnetic force of the magnetic column 24 disappears, the magnetic column 24 no longer has magnetism and cannot generate magnetic attraction to the magnet 30. That is to say, the impeller shaft 13 is not always pressed against the bearing seat 22, and the bearing seat 22 is also not always pressed against the lubricating oil A, only when the blood pump is in working state (the impeller 10 rotates to pump blood), the lubricating oil A slowly overflows through the oil guide hole 221. In the non-working state, including storage, transportation and vascular intervention / retraction process, there is no lubricating oil A overflow, which prevents the leakage of the lubricating oil A and effectively ensures the long-term lubrication of the lubricating oil A.

[0023] Generally speaking, the greater the rotation speed, the less the amount of lubricating oil A required at the friction surface, and correspondingly, the greater the rotation speed, the greater the amount of lubricating oil A required at the friction surface. In the blood pump, the rotation speed of the impeller 10 is controlled by the strength of the magnetic coupling, the greater the strength of the magnetic coupling, the greater the rotation speed of the impeller 10, and the smaller the strength of the magnetic coupling, the smaller the rotation speed of the impeller 10, and the strength of the magnetic coupling is adjusted by the electrified current of the coil winding 26. Therefore, when the rotation speed of the impeller 10 is high, the strength of the magnetic coupling is high, the magnetic attraction force is large, the pressure of the impeller shaft 13 to the bearing seat 22 is large, the extrusion force of the bearing seat 22 to the lubricating oil A is strong, and the amount of escape of the lubricating oil A is large; on the contrary, the amount of extrusion of the lubricating oil A is small, thereby realizing the self-adaptive supply of the lubricating oil A. That is to say, the technical scheme of the present application can not only realize the provision of the lubricating oil A only in the working state, prevent the leakage of the lubricating oil A and long-term use, but also automatically adjust the amount of lubricating oil A provided to realize the self-adaptive supply purpose.

[0024] In the blood pump, the stability of the impeller shaft 13 axis is particularly important, because the gap between the impeller 13 and the inner wall of the blood cage 40 at its periphery is small, if the impeller shaft 13 is deflected, the blade 13 and the inner wall of the blood cage 40 will rub, thrombosis is aggravated, and the rotation of the impeller 10 is blocked. The fixed shaft tube 21 is located at the center of the distal end of the shell 23, including the distal end extension 211 protruding towards the distal end and the proximal end extension 212 protruding towards the inner cavity of the shell 23, further improving the structural strength of the fixed shaft tube 21, preventing the fixed shaft tube 21 from deforming. The lubricating oil A is arranged in the inner cavity of the proximal end extension 212, and the inner cavity of the distal end extension 211 is provided with a guide groove 213 to prevent the lubricating oil A from leaking. The guide ribs 225 arranged on the outer periphery of the small-diameter proximal section 222 and the guide groove 213 constitute an axial guide fit, ensuring that the bearing seat 22 can only slide axially and cannot rotate.

[0025] Further, the hole core of the oil guide hole 221 coincides with the shaft core of the bearing seat 22, and the distal end of the oil guide hole 221 is located at the groove bottom position of the groove 224. The bottom of the groove 224 is the position with the largest friction and the most serious wear. Therefore, the lubricating oil A overflows from this position and spreads evenly around, effectively reducing wear.

[0026] In order to ensure that the lubricating oil A can slowly overflow, only one oil guide hole 221 is provided, and the inner diameter of the oil guide hole 221 is 0.15-0.5mm. The design of the inner diameter of the oil guide hole 221 directly affects whether the lubricating oil A can overflow, the amount of overflow, and whether it is suitable for long-term supporting auxiliary equipment.

[0027] In order to further prevent the lubricating oil A from leaking in the non-working state of the blood pump, an elastic element is arranged in the chamber between the proximal end of the fixed shaft tube 21 and the bearing seat 22, and the lubricating oil A is soaked in the elastic element. That is, the lubricating oil A is soaked in the elastic element (similar to a sponge-like substance). When it is not extruded, the lubricating oil A cannot come out of the elastic element; when the chamber is compressed, the elastic element is extruded, and the lubricating oil A inside is extruded out, and then enters the friction surface position from the oil guide hole 221.

[0028] The proximal end of the impeller shaft 13 is a hemispherical head 131, and the groove 224 is also shaped to fit the hemispherical head 131. The depth L of the groove 224 is greater than the radius R of the hemispherical head 131. That is, the part of the groove 224 beyond the hemispherical head 131 prevents the impeller shaft 13 from falling out of the groove 224, enhances the stability of rotation, and reduces the abnormal sound of rotation. The part of the groove 224 beyond the hemispherical head 131 should not be too short or too long. If it is too short, the limiting and anti-falling effect is not obvious, and if it is too long, it is not easy to assemble.

[0029] Further, the impeller 10 comprises a hub 11 and blades 12 arranged at the outer periphery of the hub 11, and an impeller shaft 13 passes through and is fixed in a through hole axially formed in the hub 11, the proximal end of the impeller shaft 13 extends into the inner cavity of the magnet 30 and abuts against the distal end of the bearing seat 22 to form axial positioning, radial positioning and circumferential rotation cooperation. The magnet 30 and the impeller 10 can be two separate components, and the magnet 30 is fixed at the proximal end of the impeller 10. In this arrangement, the volume and end face of the magnet 30 can be as large as possible to enhance the magnetic force. The magnet 30 and the impeller 10 can also be provided in an integrated structure, i.e. the magnet 30 is embedded in the inner cavity of the tail of the impeller 10. This structure can prevent the magnet 30 from directly contacting the blood and effectively protect the magnet from corrosion, thereby ensuring the stability of the performance. The bearing seat 22 is arranged in the inner cavity of the magnet 30, which effectively shortens the axial length of the rigid section of the blood pump and is beneficial to the over-bending performance of the blood pump when it is inserted or withdrawn through the blood vessel.

[0030] In order to form a blood flow channel, the outer periphery of the impeller 10 is provided with a blood cage 40, the proximal end of the blood cage 40 is welded and fixed with the distal end of the shell 23, the blood cage 40 is in the shape of a circular tube as a whole, the distal end of the circular tube forms a blood inlet, a plurality of blood outlets 41 are formed on the proximal side outer peripheral wall of the blood cage 40 along the circumferential direction, and a limiting ring 42 for supporting the distal end of the impeller shaft 13 is arranged at the circular tube opening and forms radial positioning, axial sliding and circumferential rotation cooperation. As mentioned above, the magnetic column 24 and the coil winding 26 in the driving unit 20 form an electromagnet, and only when the coil winding 26 is energized, the magnetic column 24 will generate a magnetic attraction force. When the power is off, the magnetic force on the magnetic column 24 disappears. In order to ensure the stability of the position of the impeller 10, the distal end of the impeller 10 is supported on the limiting ring 42. The limiting ring 42 not only can ensure that the distal end of the impeller shaft 131 is supported and improve the stability of the rotation of the impeller 10, but also can prevent the impeller 10 from moving when the power is off. The distal end of the impeller shaft 13 and the limiting ring 42 form radial positioning, axial sliding and circumferential rotation cooperation, which can ensure that the proximal end of the impeller shaft 13 is always pressed against the bearing seat 22. At the same time, due to the existence of the magnetic attraction force, the impeller 10 will not randomly move axially during blood pumping.

[0031] Considering the use environment and performance requirements of the blood pump, the lubricating oil A is medical silicone oil. Medical silicone oil has good biocompatibility, it will not cause adverse reactions such as blood coagulation, hemolysis or platelet aggregation, and can ensure the normal flow of blood in the blood pump; at the same time, medical silicone oil has low surface tension and good lubricating performance, and can form a uniform and stable lubricating film on the bearing surface. This layer of lubricating film separates the friction pair surfaces of the bearing, so that the original material direct contact is changed to the relative sliding between the lubricant molecules, thereby significantly reducing the friction coefficient. In addition, medical silicone oil has good chemical inertness and will not chemically react with various components in the blood and the bearing material, thereby ensuring the normal operation of the blood pump.

[0032] Of course, the present application is not limited to the details of the above-described exemplary embodiments but encompasses rather similar or equivalent structures which can be realized in other concrete forms without departing from the spirit or essential characteristics of the present application. Thus, the embodiments should be considered in all respects as illustrative and not restrictive, the scope of the application being defined by the appended claims rather than the above description, and it is intended that all changes which come within the meaning and range of equivalency of the claims are embraced therein. No reference signs in the claims should be construed as limiting the scope of the claims to the features

[0033] Furthermore, it should be understood that although the present specification has been described in language specific to structural features, material or methodological acts, the present application is not necessarily limited to the specific details or the manner in which the various embodiments are described. Rather, the specific features, material or acts are disclosed as exemplary forms of implementing the embodiments.

Claims

1. A blood pump comprising an axially arranged impeller (10) and a drive unit (20), a proximal end of the impeller (10) being connected with a magnet (30), the drive unit (20) and the magnet (30) constituting an end face magnetic coupling driving structure, a proximal end support assembly being arranged at a distal end of the drive unit (20), characterized in that: The proximal end supporting assembly comprises a fixed shaft tube (21) and a bearing seat (22), and the two are in circumferential limiting and axial sliding fit; the proximal end of the impeller (10) is rotatably supported in the bearing seat (22); the chamber between the fixed shaft tube (21) and the proximal end of the bearing seat (22) is provided with lubricating oil (A); and the bearing seat (22) is provided with oil guide holes (221) penetrating through both ends thereof. ​ 2. The blood pump of claim 1, wherein: The bearing seat (22) comprises a small-diameter proximal section (222) and a large-diameter distal section (223); the inner diameter of the small-diameter proximal section (222) is consistent with the inner diameter of the fixed shaft tube (21) and forms a sealing fit; and the distal end face of the large-diameter distal section (223) is provided with a groove (224); the proximal end of the impeller shaft (13) is arranged in the groove (224) to form axial limiting, radial limiting and circumferential rotating fit.

3. The blood pump of claim 2, wherein: The driving unit (20) comprises a housing (23); a plurality of magnetic columns (24) are arranged in the housing (23) at intervals; the proximal ends of the plurality of magnetic columns (24) are inserted into the mounting holes of the stator seat (25) to form fixed connection; the plurality of magnetic columns (24) are uniformly and interval arranged on the circumferential surface of a same cylinder, and the center line of the cylinder is collinear with the rotation axis of the impeller (10); the coil winding (26) is wound on the outer periphery of the magnetic column (24) to form an electromagnet structure; when the coil winding (26) is electrified, the magnetic attraction force between the magnetic column (24) and the magnet (30) drives the proximal end of the impeller (10); and the rotating magnetic field generated by the electromagnet structure drives the impeller (10) to rotate.

4. The blood pump of claim 3, wherein: The fixed shaft tube (21) is located at the center position of the distal end of the housing (23) and comprises a distal end extension section (211) protruding towards the distal end and a proximal end extension section (212) protruding towards the inner cavity of the housing (23); the lubricating oil (A) is arranged in the inner cavity of the proximal end extension section (212); the inner cavity of the distal end extension section (211) is provided with a guide groove (213); and the guide ribs (225) arranged on the outer periphery of the small-diameter proximal section (222) form axial guide fit with the guide groove (213).

5. The blood pump of claim 4, wherein: The hole core of the oil guide hole (221) coincides with the shaft core of the bearing seat (22); the distal end of the oil guide hole (221) is located at the groove bottom position of the groove (224); and the inner diameter of the oil guide hole (221) is 0.15-0.5mm.

6. The blood pump of claim 1, wherein: The chamber between the fixed shaft tube (21) and the proximal end of the bearing seat (22) is provided with an elastic element; and the lubricating oil (A) is infiltrated in the elastic element.

7. The blood pump of claim 2, wherein: The proximal end of the impeller shaft (13) is a hemispherical head (131); the groove (224) also has a shape consistent with the hemispherical head (131); and the depth L of the groove (224) is greater than the radius R of the hemispherical head.

8. The blood pump of claim 1, wherein: The impeller (10) comprises a hub (11) and blades (12) arranged on the outer periphery thereof; the impeller shaft (13) passes through and is fixed in the through hole axially formed in the hub (11); the proximal end of the impeller shaft (13) extends into the inner cavity of the magnet (30) and abuts against the distal end of the bearing seat (22) to form axial limiting, radial limiting and circumferential rotating fit.

9. The blood pump of claim 8, wherein: The outer periphery cover of the impeller (10) is provided with a blood cage (40), the proximal end of the blood cage (40) is welded and fixed with the distal end of the shell (23), the blood cage (40) is in the form of a whole circular tube, the distal end of the circular tube forms a blood inlet, a plurality of blood outlets (41) are formed on the proximal side outer periphery wall of the blood cage (40) along the circumferential direction, a limiting ring (42) for supporting the distal end of the impeller shaft (13) is further arranged at the circular tube opening, and the two form a radial limiting, axial sliding and circumferential rotating cooperation.

10. The blood pump of claim 1, wherein: The lubricating oil (A) is medical silicone oil.

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