A heart blood pump

Abstract

The application provides a heart blood pump with a sealing structure, the sealing structure comprising a sealing member and a non-flow stagnation area. A streamlined non-flow stagnation area is formed at the connection between the impeller and the power mechanism, so that blood flowing through the area does not stagnate and directly flows through. In combination with the use of the sealing member, further sealing is achieved, so that blood clots are avoided at the connection between the impeller hub and the output shaft, and blood is prevented from seeping from the connection into the power mechanism to cause a shutdown failure.

Description

[0001] This application is a divisional application of the patent application with the application number 202011045446.8 and the application date of September 28, 2020, and the invention name of "a sealing mechanism and a heart blood pump". TECHNICAL FIELD

[0002] The present application relates to the technical field of medical device design, in particular to a heart blood pump. BACKGROUND

[0003] Heart failure refers to the condition that the heart cannot fully discharge the blood volume from the veins to the arteries due to the dysfunction of the systolic and / or diastolic function of the heart, resulting in the accumulation of blood in the venous system and the insufficient perfusion of blood in the arterial system, thereby causing the syndrome of heart circulation disorder.

[0004] The current treatment methods for heart failure include drug therapy, heart transplantation and left ventricular assist device. The left ventricular assist device is to pump blood through a heart blood pump to promote the flow of blood in the heart. This scheme has the advantages of good treatment effect and low cost, but it has problems such as the entry of blood into the blood pump in the heart, causing thrombosis, and the shutdown of the motor of the blood pump in the heart.

[0005] For the current blood pump in the heart, in order to avoid blood entering the motor and causing thrombosis or shutdown failure, a sealing structure (US5911685) or a motor flushing device (US10610626) is usually used. The existing two schemes still have the following problems:

[0006] 1. The motor flushing device (US10610626) type blood pump needs an extra complex motor flushing device (such as a peristaltic pump) to provide flushing liquid for the motor. The pressure of the flushing liquid is greater than the blood pressure, so as to avoid the entry of blood into the motor. If any part of the flushing device fails, the blood pump will also fail, reducing the reliability of the system.

[0007] 2. The sealing structure of the sealing structure type blood pump (US20100041939A1) uses traditional industry sealing elements. There are gaps or obstructions in the forward direction of the fluid, which can easily form a blood flow stagnation area near the sealing element. The blood in the blood flow stagnation area has no forward speed, gradually coagulates to form a thrombus, or forms a biological compatibility problem caused by the wear of the sealing material. SUMMARY

[0008] In view of the problems in the background art, the present application provides a heart blood pump, which is provided with a sealing mechanism, the sealing mechanism comprising a radial seal and a streamlined non-flow stagnation zone formed in the housing near the second opening part, wherein the outer ring surface of the radial seal is in a shape extending in a streamlined manner from the hub to the side of the radial opening, and the streamlined outer ring surface of the radial seal and the housing form a streamlined non-flow stagnation zone, so that the fluid directly flows through the area in a streamlined manner and does not stagnate;

[0009] The outer ring surface of the far end of the base of the heart blood pump away from the impeller is in a streamlined shape of decreasing size, so that the blood flowing out of the radial opening does not swirl and stagnate when flowing through the streamlined outer ring surface of the end;

[0010] The radial seal is coaxially sleeved at one end of the hub and connected to the housing at the opposite end, the radial seal is provided with multiple radial seals, and multiple contacts between the inner ring of the radial seal and the hub or the output shaft form multiple seals, wherein the inner ring of the one end of the radial seal towards the impeller is in interference fit with the hub or the output shaft to form the first seal; the outer ring surface of the hub or the output shaft is circumferentially provided with a first protrusion, the first protrusion is in contact with the inner ring surface of the radial seal to form the second seal; the inner ring surface of the radial seal is provided with a second protrusion, the second protrusion is in contact with the hub or the output shaft to form the third seal;

[0011] The housing is provided with guide vanes between adjacent radial openings, the guide vanes are arranged along the housing between the adjacent radial openings, the guide vanes are connected to the seal or the power mechanism, and the distance between the outer diameter of the blades of the impeller and the inner wall of the housing is 0.1-0.2mm, and the thickness of the blades of the impeller is 0.1-0.8mm.

[0012] In one of the embodiments, the heart blood pump is provided with a sealing mechanism, the sealing mechanism comprising an axial seal and a streamlined non-flow stagnation zone formed in the housing near the second opening part, wherein the hub of the heart blood pump is sleeved on the output shaft of the heart blood pump and fixedly connected, the outer ring surface of the hub at one end near the axial seal is in a streamlined shape along the axial direction, and the streamlined outer ring surface is located at the radial opening, and the streamlined outer ring surface of the hub and the housing form a streamlined non-flow stagnation zone, so that the fluid directly flows through the area in a streamlined manner and does not stagnate,

[0013] The outer ring surface of the far end of the base of the heart blood pump away from the impeller is in a streamlined shape of decreasing size, so that the blood flowing out of the radial opening does not swirl and stagnate when flowing through the streamlined outer ring surface of the end;

[0014] The axial seal is a multi-channel axial seal, and multiple contacts between the end face of the axial seal and the hub end face form multiple seals, wherein the end face edge of the axial seal towards the hub has a sealing plane, and the sealing plane contacts the hub end face to form a first seal; the end face of the hub towards the axial seal is provided with a third protrusion, and the third protrusion contacts the axial seal to form a second seal.

[0015] The guide blades are arranged between the adjacent radial openings in the shell, and the guide blades are connected with the sealing element or the power mechanism, and the distance between the outer diameter of the blade of the impeller and the inner wall of the shell is 0.1-0.2 mm, and the thickness of the blade of the impeller is 0.1-0.8 mm.

[0016] In one of the embodiments, the heart blood pump is combined with the streamlined non-flow stagnation zone and the sealing element, so that blood does not form thrombus at the connection between the hub of the impeller and the output shaft.

[0017] In one of the embodiments, the output shaft drives the impeller to rotate relative to the shell, so that the blood enters the shell from the first opening part, is axially pushed to the streamlined non-flow stagnation zone under the pushing action of the impeller, flows through the connection between the impeller and the power mechanism in a streamlined manner under the action of the streamlined non-flow stagnation zone, and is then directly output from the second opening part; or the output shaft drives the impeller to rotate relative to the shell, so that the blood enters the shell from the second opening part, flows through the connection between the impeller and the power mechanism in a streamlined manner under the action of the streamlined non-flow stagnation zone, and is then axially pushed to the first opening part under the pushing action of the impeller and is output from the first opening part.

[0018] In one of the embodiments, the second opening part is arranged to be inclined relative to the axial direction, and the inclined direction of the second opening part matches the flow direction of the blood.

[0019] In one of the embodiments, the one end of the radial sealing element is sleeved on the outer ring surface of the hub to realize dynamic sealing; the other end of the radial sealing element is sleeved on the second stepped part of the end part of the base, and the outer ring surface at the edge of the other end of the radial sealing element is attached to and fixedly connected with the inner wall surface of the shell, and the other end of the radial sealing element realizes static sealing with the base and the shell.

[0020] In one of the embodiments, the one end of the radial sealing element is sleeved on the outer ring surface of the hub to realize dynamic sealing; the other end of the radial sealing element is sleeved on the second stepped part of the end part of the base, and the outer ring surface at the edge of the other end of the radial sealing element is attached to and fixedly connected with the inner wall surface of the shell, and the other end of the radial sealing element realizes static sealing with the base and the shell.

[0021] In one of the embodiments, the first protrusion is a structure integrally formed around the hub outer ring or a sealing ring arranged on the hub outer ring; and the second protrusion is a structure integrally formed on the inner ring of the radial seal or a structure arranged on the inner ring of the radial seal.

[0022] In one of the embodiments, the first protrusion is a structure integrally formed around the hub outer ring or a sealing ring arranged on the hub outer ring; and the second protrusion is a structure integrally formed on the inner ring of the radial seal or a structure arranged on the inner ring of the radial seal.

[0023] In one of the embodiments, the guide vane can facilitate the flow regulation of the blood at the second opening, reduce the circumferential rotation speed component of the blood, increase the axial linear speed component, and increase the blood flow.

[0024] Compared with the prior art, the present application has the following advantages and positive effects:

[0025] The heart blood pump provided by the present application forms a streamlined non-flow stagnation zone at the connection between the impeller and the power mechanism, so that the blood does not stagnate when flowing through the zone and directly flows through, and further sealing is achieved by cooperating with the use of the seal, thereby avoiding the formation of blood clots at the connection between the hub of the impeller and the output shaft, and avoiding the penetration of blood from the connection into the power mechanism to cause shutdown failure. BRIEF DESCRIPTION OF DRAWINGS

[0026] The above and other features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:

[0027] Figure 1 A cross-sectional view of the sealing mechanism provided for the embodiment 1 of the present application;

[0028] Figure 2 A structural view of the radial seal in the embodiment 1 of the present application;

[0029] Figure 3 A cross-sectional view of the sealing mechanism provided for the embodiment 2 of the present application;

[0030] Figure 4 A partial view of the position A in the embodiment 2 of the present application;

[0031] Figure 5 A structural view of the radial seal in the embodiment 2 of the present application;

[0032] Figure 6 A cross-sectional view of the sealing mechanism provided for the embodiment 3 of the present application;

[0033] Figure 7 A partial view of the position B in the embodiment 3 of the present application;

[0034] Figure 8 Structure diagram of axial seal in embodiment 3 of the present application;

[0035] Figure 9 Sectional diagram of sealing mechanism provided in embodiment 4 of the present application;

[0036] Figure 10 Partial diagram of C in embodiment 4 of the present application. DETAILED DESCRIPTION

[0037] The present application will be described in more detail with reference to the drawings, in which embodiments of the present application are shown. The present application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the application to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions are exaggerated for clarity.

[0038] It should be noted that all directional references (e.g., upper, lower, left, right, front, rear, etc.) are in relation to the exemplary embodiment of the present application as illustrated in the drawings and are used only for the purpose of explanation of the present application. The directional references are not intended to limit the scope of the present application.

[0039] The present application provides a sealing mechanism for sealing the connection between an impeller and a power mechanism. The power mechanism has an output end connected to a housing, and the impeller is located in the housing and connected to the output shaft of the power mechanism. The housing has a first opening and a second opening for fluid flow. The first opening is located at one end of the housing away from the power mechanism, and the second opening is located at one end of the housing near the connection between the power mechanism and the impeller. The sealing mechanism includes a first sealing portion and a second sealing portion. The first sealing portion is a streamlined non-flow stagnation zone formed in the housing near the second opening. Under the action of the impeller, fluid from the first opening or the second opening flows through the streamlined non-flow stagnation zone, and the fluid directly flows in a streamlined manner without stagnation. The second sealing portion is a sealing element provided between the impeller or the output shaft and the power mechanism. The sealing element forms a dynamic seal with the output shaft or the impeller.

[0040] The output shaft of the power mechanism drives the impeller to rotate relative to the casing and the power mechanism, so that the fluid enters the casing from the first opening part, is axially pushed to the streamline non-flow stagnation area under the pushing action of the impeller, is streamlined through the connection part of the impeller and the power mechanism under the action of the streamline non-flow stagnation area, and is then directly output from the second opening part; or the output shaft of the power mechanism drives the impeller to rotate relative to the casing and the power mechanism, so that the fluid enters the casing from the second opening part, is streamlined through the connection part of the impeller and the power mechanism under the action of the streamline non-flow stagnation area, and is then axially pushed to the first opening part under the pushing action of the impeller and is output from the first opening part; the switching of the first opening part and the second opening part as the inlet and outlet can be realized by adjusting the rotation direction of the impeller.

[0041] The streamline non-flow stagnation area adjusts the streamline of the area through which the fluid flows by using the characteristics of the fluid, so that the fluid does not occur turbulence, rotation and other problems in the area, directly flows through the area without stagnation, and the specific shape of the streamline can be adjusted according to specific factors, for example, the flow rate of the fluid, the pipe diameter of the casing, the density of the fluid and other factors, and the area can be adjusted and simulated multiple times according to specific conditions, so that the fluid flowing through the area does not occur stagnation.

[0042] The sealing mechanism provided by the application is suitable for sealing in a heart blood pump, a streamline non-flow stagnation area is formed at the connection part of the impeller and the power mechanism, so that the blood flowing through the area does not occur stagnation, directly flows through, and is further sealed by cooperating with the sealing element, thereby avoiding the formation of blood clots at the connection part of the impeller hub and the output shaft, and avoiding the leakage of blood from the connection part into the power mechanism to cause shutdown failure.

[0043] The application breaks through the inherent thinking of only using a sealing element for sealing in the existing heart blood pump, and initiates the combination of a streamline non-flow stagnation area and a sealing element to solve the problem of blood entering the power mechanism to cause blood clots or shutdown failure, proposes a new sealing concept, and has the advantages of simple structure and low cost.

[0044] The sealing mechanism provided by the application can be applied to a heart blood pump in a left ventricular assist device, in which case the first opening part serves as a blood inlet and the second opening part serves as a blood outlet; or can be applied to a heart blood pump in a right ventricular assist device, in which case the second opening part serves as a blood inlet and the first opening part serves as a blood outlet. The sealing mechanism provided by the application is not limited to the above devices, but can also be applied to other devices, which are not limited here.

[0045] The following will be further described by taking the heart blood pump in a left ventricular assist device as an example:

[0046] Embodiment 1

[0047] Reference Figures 1-2 In the embodiment, the power mechanism comprises a base 4 and a power member, which can be an electric motor 5. The electric motor 5 is coaxially arranged in the base 4, and an output shaft 501 of the electric motor 5 extends out of the base 4.

[0048] In the embodiment, the electric motor 5 is completely arranged in the base 4. Of course, in other embodiments, the electric motor 5 can not be completely arranged in the base 4, as long as the electric motor 5 is arranged on the base 4. In other embodiments, the base 4 can be combined with a housing of the electric motor 5.

[0049] In the embodiment, the shell 1 is a cylindrical hollow thin-walled structure, one end of which is coaxially arranged on a first stepped portion 402 at an end of the base 4 and is fixedly connected to the base 4 by welding or bonding. The transition between the base 4 and the shell 1 avoids scratching the tissue when the heart blood pump is inserted into the heart.

[0050] The impeller 2 is an axial flow impeller, which comprises a hub 201 and blades arranged on the hub. The hub 201 is coaxially and fixedly connected to the output shaft 501. In the embodiment, the hub 201 is arranged on the output shaft 501 to achieve fixed connection. Of course, in other embodiments, the output shaft 501 can be arranged on the hub 201.

[0051] In the embodiment, an end face of the shell 1 away from the electric motor 5 is open to form an axial opening 101. A plurality of radial openings 102 are uniformly distributed on an outer ring face of the shell 1 towards the electric motor 5, and are arranged close to a connection between the hub 201 and the output shaft 501. The electric motor 5 drives the impeller 2 to rotate, so that the blood enters the shell 1 from the axial opening 101, and flows to the side of the radial opening under the pushing action of the impeller 2 and is discharged from the radial opening 102.

[0052] In the embodiment, the radial openings 102 are arranged obliquely relative to the axial direction. Since the blood in the shell 1 flows in a spiral manner under the pushing action of the impeller 2, the oblique direction of the radial openings 102 matches the flow direction of the blood, so as to ensure that the blood can flow out of the radial openings 102 smoothly and quickly.

[0053] In the embodiment, the distance between the outer diameter of the blades 202 of the impeller 2 and the inner wall of the shell 1 is 0-0.3 mm, and is preferably 0.1-0.2 mm. Such a distance can prevent the blades 202 from colliding with the shell 1 during rotation, and the distance cannot be too large to ensure the smooth advancement of the blood in the shell 1 in the axial direction. The distance between the outer diameter of the blades 202 of the impeller 2 and the inner wall of the shell 1 can be selected according to the diameter of the shell, the flow rate and other factors.

[0054] The thickness of the blade 202 of the impeller 2 is 0.1-0.8 mm, which ensures the strength of the blade 202 and maximally ensures the flow of blood circulation. The thickness of the blade 202 can be selected according to the diameter of the shell, the flow rate and other factors, which is not limited here.

[0055] The outer ring surface 401 of the far end of the frame 4 away from the impeller is in a tapered streamline shape, and the blood flowing out of the radial opening 102 flows to the far end of the frame 4 away from the impeller, and flows through the tapered outer ring surface 401, so that the blood does not swirl or stagnate at the end, and the smooth flow of the blood can be ensured.

[0056] In this embodiment, a radial seal 3 is arranged on the end of the hub 201 connected to the output shaft 501; one end of the radial seal 3 is sleeved on the outer ring surface of the hub 201 to realize dynamic sealing. Of course, when the output shaft is sleeved on the hub, the other end of the radial seal 3 is sleeved on the outer ring surface of the output shaft, which is not limited here; the other end of the radial seal 3 is sleeved on the second step portion 403 of the end of the frame 4, and the outer ring surface of the other end edge of the radial seal 3 is attached to and fixedly connected with the inner wall surface of the shell 1, and static sealing is realized between the other end of the radial seal 3 and the frame 4 and the shell 1.

[0057] The outer ring surface 301 of the radial seal 3 towards the radial opening 102 is in a streamlined shape along the axial direction, so that the streamlined outer ring surface 301 of the radial seal 3 and the inner wall of the shell 1 form a streamlined non-flow stagnation area; further, the outer ring surface of the radial seal 3 is in a shape extending in a streamlined manner from the hub 201 to the side of the radial opening 102, so that the blood transported from the blade 202 flows out of the radial opening 102 in a streamlined manner when passing through the radial seal 3, preventing the blood from stagnating at this position.

[0058] The radial seal 3 has radial elasticity and can be elastically deformed to function as a radial buffer.

[0059] In this embodiment, the radial seal 3 is a single radial seal, and the inner ring of the radial seal 3 only contacts the hub 201 or the output shaft 501 at one position to form a single seal. Specifically, the inner ring of the radial seal 3 is in a conical shape, so that only the inner ring 302 of the radial seal towards the impeller is in interference fit with the hub 201 / output shaft 501 to realize dynamic sealing, so as to prevent the blood from seeping in.

[0060] In this embodiment, the material of the radial seal 3 is a biocompatible wear-resistant material, such as biocompatible wear-resistant ceramic or biocompatible wear-resistant plastic or biocompatible wear-resistant rubber, which can reduce the generation of wear particles and avoid the problems of hemolysis and thrombosis near the seal and biocompatibility.

[0061] Other structures in contact with blood in this embodiment also adopt biocompatible materials, such as the impeller, the shell, the base, etc.

[0062] Embodiment 2

[0063] This embodiment is an adjustment based on Embodiment 1. In this embodiment, the radial seal 3 is a multi-channel radial seal, and the inner ring of the radial seal 3 contacts the hub 201 / output shaft 501 at multiple positions to form multiple seals.

[0064] Specifically, referring to Figures 3-5 In this embodiment, the inner ring 302 of the end of the radial seal 3 towards the impeller 2 is in interference fit with the hub 201 or the output shaft 501 to form the first seal.

[0065] Further, the outer ring surface of the hub 201 (or the output shaft 501) is circumferentially provided with a first protrusion 203, and the first protrusion 203 contacts the inner ring surface of the radial seal 3 to form the second seal; wherein the first protrusion 203 can be a structure directly integrally formed on the outer ring of the hub 201, or it can be a sealing ring set on the outer ring of the hub 201, which is not limited here and can be adjusted according to specific conditions.

[0066] Further, the inner ring surface of the radial seal 3 is provided with a second protrusion 303, and the second protrusion 303 contacts the hub 201 (or the output shaft 501) to form the third seal; wherein the second protrusion 303 can be a structure directly integrally formed on the inner ring of the radial seal 3, or it can be a structure set on the inner ring of the radial seal 3, which is not limited here and can be adjusted according to specific conditions.

[0067] In this embodiment, three seals are adopted, thereby greatly improving the sealing effect, and even if the first seal fails, there is a subsequent seal; of course, in other embodiments, there can be only two seals, or more than three seals, which is not limited here as long as it is a labyrinth seal structure.

[0068] In this embodiment, guide vanes 304 are arranged between adjacent radial openings 102 in the shell 1, and the guide vanes 304 are arranged along the shell 1 between the adjacent radial openings 102, wherein the guide vanes 304 can be arranged vertically with the shell or can be arranged inclinedly with respect to the shell, which is not limited here and can be adjusted according to specific conditions; further, in this embodiment, one side of the guide vane 304 is connected to the outer ring surface of the radial seal 3, and the other side extends to the shell between the adjacent radial openings 102, as shown in Figure 5 of course, in other embodiments, the guide vanes can be fixedly connected to the shell 1 or the base 4, which is not limited here.

[0069] The present embodiment is provided with the guide vane 304, which facilitates the rectification of the blood at the radial opening 102, reduces the circumferential rotation speed component of the blood, increases the axial linear speed component, and increases the blood flow.

[0070] In the present embodiment, the other specific structures of the sealing mechanism can be referred to the description in Embodiment 1.

[0071] Embodiment 3

[0072] The present embodiment is an adjustment based on Embodiment 1, and an axial seal is used in the present embodiment.

[0073] Referring to Figures 6-8 In the present embodiment, the axial seal 8 is coaxially arranged with the impeller 2 and the housing 4, and specifically, the axial seal 8 is coaxially sleeved on the second stepped portion at the end of the housing 4. The one end of the axial seal 8 in the axial direction is in contact with the end surface of the hub 201 to achieve dynamic sealing, and the other end is in contact with the housing 4 to achieve static sealing. The outer ring surface of the axial seal 8 is in contact with the inner surface of the housing 1 to achieve static sealing. Further, the axial seal 8 is fixedly connected with the housing 1.

[0074] The axial seal 8 is a single-channel axial seal, and there is only one contact between the end surface of the axial seal 8 and the end surface of the hub 201 to form a seal. Further, the end surface 204 of the one end of the axial seal 8 towards the hub 201 has a sealing plane 801 in contact with the hub, and the sealing plane 801 is located at the edge of the end surface of the axial seal 8, as shown in FIG. 8. Figure 8 In this way, the gap between the hub 201 and the housing 1 is ensured, as shown in FIG. 9, thereby avoiding the stagnation of blood at this position to generate thrombus. Figure 7

[0075] Of course, the axial seal 8 can also be a multi-channel seal structure in other embodiments, which is not limited here.

[0076] The axial seal 8 is an axial elastic seal to ensure a certain buffering effect when the blood axially impacts the impeller 2. Specifically, the outer ring surface of the axial seal 8 is provided with an inner recess 803 along the circumferential direction to realize the axial elasticity. Of course, the inner recess 803 can not be provided in other embodiments, and it is a elastic structure itself, which is not limited here and can be adjusted according to the specific circumstances.

[0077] Further, the axial seal 8 is axially elastic.

[0078] ​In the embodiment, the hub 201 is sleeved on the output shaft 501 and fixedly connected, the outer ring surface of the hub 201 near one end of the axial seal 8 is streamlined along the axial direction, and the streamlined outer ring surface is located at the radial opening 102; the streamlined outer ring surface of the hub 201 and the shell 1 form a streamlined non-flow stagnation zone.

[0079] In the embodiment, other specific structures of the sealing mechanism can be referred to the description in the embodiment 1.

[0080] Embodiment 4

[0081] The embodiment is based on the adjustment of the embodiment 3.

[0082] Referring to Figures 9-10 In the embodiment, the one end of the axial seal 9 extending towards the hub 201 has a structure extending in the axial direction, and the outer ring surface of the axial seal 9 is opposite to the radial opening; and the outer ring surface 901 of the extending section is streamlined, and the streamlined outer ring surface 901 of the extending section and the shell 1 form a streamlined non-flow stagnation zone.

[0083] In the embodiment, the axial seal 9 is a plurality of radial seals; specifically, as shown in Figure 10 The end surface edge of the one end of the axial seal 8 extending towards the hub 201 has a sealing plane 902 in contact with the hub, forming a first seal; and the end surface of the hub 201 is provided with a third protrusion 205 in contact with the axial seal 9, forming a second seal.

[0084] In the embodiment, the guide blade 904 is arranged between the adjacent radial openings 102 in the shell 1 and perpendicular to the shell 1; further, in the embodiment, one side of the guide blade 904 is connected with the outer ring surface of the axial seal 9, and the other side extends to the shell between the adjacent radial openings 102, as shown in Figure 10

[0085] In the embodiment, the guide blade 904 is arranged, which facilitates the rectification of the blood at the radial opening 102, reduces the circumferential rotation speed component of the blood, increases the axial linear speed component, and increases the blood flow.

[0086] In the embodiment, other specific structures of the sealing mechanism can be referred to the description in the embodiment 3.

[0087] Those skilled in the art should understand that the present application can be implemented in many other specific forms without departing from the spirit or scope thereof. Although the embodiments of the present application have been described, it should be understood that the present application should not be limited to these embodiments, and those skilled in the art can make changes and modifications within the spirit and scope of the present application as defined in the appended claims.​

Claims

1. A cardiac blood pump, characterized in that: The cardiac blood pump is equipped with a sealing mechanism, which includes a radial seal and a streamlined non-flow stagnation zone formed in the housing near the radial opening. The outer ring of the radial seal has a streamlined shape extending from the hub to the radial opening. The streamlined outer ring of the radial seal and the housing constitute the streamlined non-flow stagnation zone, allowing fluid to flow directly through the zone and out in a streamlined manner without stagnation. The outer ring surface of the base of the cardiac blood pump away from the impeller is a tapered streamline shape, so that the blood flowing out from the radial opening will not swirl or stagnate as it passes through the streamlined outer ring surface at this end. One end of the radial seal is coaxially fitted onto the hub, and the other end is connected to the housing. The radial seal is a multi-stage radial seal, with multiple contacts between the inner ring of the radial seal and the hub or output shaft to form multiple seals. Specifically, the inner ring of the radial seal facing the impeller is press-fitted with the hub or output shaft to form a first seal. The outer ring surface of the hub or output shaft has a first protrusion circumferentially arranged, and the first protrusion contacts the inner ring surface of the radial seal to form a second seal. The inner ring surface of the radial seal has a second protrusion, and the second protrusion contacts the hub or output shaft to form a third seal. Guide vanes are provided between adjacent radial openings within the housing. The guide vanes are arranged along the housing between adjacent radial openings. The guide vanes are connected to the seal or power mechanism. The distance between the outer diameter of the impeller blade and the inner wall of the housing is 0.1-0.2 mm, and the thickness of the impeller blade is 0.1-0.8 mm.

2. The cardiac blood pump according to claim 1, characterized in that, One end of the radial seal is fitted onto the outer ring surface of the hub to achieve dynamic sealing; the other end of the radial seal is fitted onto the second step portion at the end of the base, and the outer ring surface at the edge of the other end of the radial seal is in contact with and fixedly connected to the inner wall surface of the housing, and the other end of the radial seal achieves static sealing between the base and the housing.

3. The cardiac blood pump according to claim 1, characterized in that, The first protrusion is either integrally formed on the outer circumference of the wheel hub or a set of sealing rings on the outer circumference of the wheel hub; the second protrusion is either integrally formed on the inner ring of the radial seal or a set of sealing rings on the inner ring of the radial seal.

4. A cardiac blood pump, characterized in that: The aforementioned cardiac blood pump is equipped with a sealing mechanism, which includes an axial seal and a streamlined non-flow stagnation zone formed within the housing near the radial opening. The hub of the cardiac blood pump is fitted onto the output shaft of the cardiac blood pump and fixedly connected. The outer ring surface of the hub near the axial seal is streamlined along its axial direction, and the streamlined outer ring surface is located at the radial opening. The streamlined outer ring surface of the hub and the housing constitute the streamlined non-flow stagnation zone, allowing fluid to flow directly through this zone and exit in a streamlined manner without stagnation. The outer ring surface of the base of the cardiac blood pump away from the impeller is a tapered streamline shape, so that the blood flowing out from the radial opening will not swirl or stagnate as it passes through the streamlined outer ring surface at this end. The axial seal is a multi-stage axial seal, with multiple contacts between the end face of the axial seal and the end face of the hub to form multiple seals. Specifically, the edge of the end face of the axial seal facing the hub has a sealing plane, which contacts the end face of the hub to form a first seal. A third protrusion is provided on the end face of the hub facing the axial seal, and this third protrusion contacts the axial seal to form a second seal. Guide vanes are provided between adjacent radial openings within the housing. The guide vanes are arranged along the housing between adjacent radial openings. The guide vanes are connected to the seal or power mechanism. The distance between the outer diameter of the impeller blade and the inner wall of the housing is 0.1-0.2 mm, and the thickness of the impeller blade is 0.1-0.8 mm.

5. The cardiac blood pump according to claim 4, characterized in that, The radial opening is inclined relative to the axial direction, and the inclination direction of the radial opening matches the blood flow direction.

6. The cardiac blood pump according to claim 4, characterized in that, The axial seal is coaxially sleeved on the second step at the end of the base. One end of the axial seal contacts the end face of the hub to achieve dynamic sealing, and the other end contacts the base to achieve static sealing. The outer ring of the axial seal contacts the inner surface of the housing to achieve static sealing.

7. The cardiac blood pump according to claim 1 or 4, characterized in that, The guide vanes facilitate the rectification of blood flow at the radial opening, reduce the circumferential rotational velocity component of the blood, increase the axial linear velocity component, and increase the blood flow rate.

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