Blood pump

Abstract

The invention relates to a blood pump. The blood pump comprises a pump shell and an impeller; the pump shell is provided with a near-side opening; the impeller is arranged in the pump shell in a rotatable mode. Wherein the pump shell comprises an expansion pipe for accommodating the impeller, and the expansion pipe comprises a first shape memory material, so that the expansion pipe has an initial form and an expansion form which expands relative to the initial form; the first shape memory material can deform under the blood temperature condition, so that the expansion tube is expanded from an initial form to an expanded form. According to the blood pump, hemolysis can be reduced, and the safety performance of the blood pump is improved.

Description

Technical Field

[0001] This application relates to the technical field of medical devices, and particularly to a blood pump. Background Art

[0002] Blood pumps are mostly used to push blood from blood vessels to a patient's heart to assist the patient's heart in pumping blood from the ventricles to the arteries, thereby providing support for the patient's blood circulation. A blood pump has an impeller, and driving the impeller to rotate can drive blood flow. When the blood pump is working, during the process of blood flowing through the impeller, hemolysis is likely to occur, resulting in some potential safety hazards in the blood pump. Summary of the Invention

[0003] Based on this, it is necessary to provide a blood pump aimed at reducing hemolysis and improving the safety performance of the blood pump.

[0004] In one embodiment of the blood pump provided by this application, the blood pump includes a pump housing and an impeller; the pump housing is provided with a proximal opening; the impeller is rotatably arranged in the pump housing. Among them, the pump housing includes an expansion tube for accommodating the impeller, and the expansion tube includes a first shape memory material, so that the expansion tube has an initial shape and an expanded shape that expands relative to its initial shape; the first shape memory material can deform under blood temperature conditions, causing the expansion tube to expand from the initial shape to the expanded shape.

[0005] In some of these embodiments, the expansion tube at least further has one of the following characteristics:

[0006] The first shape memory material is a shape memory metal;

[0007] The temperature at which the first shape memory material deforms is 34°C to 39°C;

[0008] The shape of the expansion tube in the initial shape is a circular tube;

[0009] The expansion tube in the initial shape does not require external force to maintain;

[0010] The expansion tube in the expanded shape can be accommodated in the aorta;

[0011] The maximum outer diameter of the expansion tube in the expanded shape allows the expansion tube to pass through the narrowest position on the in-vivo delivery path.

[0012] In some of these embodiments, the impeller includes a second shape memory material, so that the impeller also has an initial shape and an expanded shape that expands relative to its initial shape; the second shape memory material can deform under blood temperature conditions, causing the impeller to expand from the initial shape to the expanded shape.

[0013] In some of these embodiments, the impeller further has at least one of the following features:

[0014] The second shape memory material is a shape memory metal;

[0015] The temperature at which the second shape memory material deforms is 34°C to 39°C;

[0016] The impeller does not require external force to maintain its initial shape.

[0017] In some of these embodiments, when the expansion tube is in its initial shape, its inner diameter is the contracted inner diameter D 1a , and when the impeller is in its initial shape, its diameter is the initial diameter D 5a , and when the impeller is in its expanded shape, its diameter is the working diameter D 5b , where D 5b > D 5a , and D 5b ≥ D 1a .

[0018] In some of these embodiments, when the impeller is in its expanded shape, its diameter is the working diameter D 5b ; the pump housing further includes a proximal tube, the proximal tube is connected to the proximal end of the expansion tube and is provided with the proximal opening, the proximal tube is a non-deformable structure, and the working diameter D 5b is greater than the inner diameter of the proximal tube; and / or,

[0019] The pump housing further includes a distal tube, the distal tube is connected to the distal end of the expansion tube, the distal tube is a non-deformable structure, and the working diameter D 5b is greater than the inner diameter of the distal tube.

[0020] In some of these embodiments, the impeller is a non-expandable rigid impeller; when the expansion tube is in its initial shape, the width of the radial gap between the inner wall surface of the expansion tube and the impeller is 0 mm to 0.06 mm or 0.08 mm to 2 mm.

[0021] In some of these embodiments, when the expansion tube is in its expanded shape, the width of the radial gap between the inner wall surface of the expansion tube and the impeller is 0.1 mm to 0.3 mm.

[0022] In some of these embodiments, the expansion tube is provided with a deformation hole, the deformation hole extends along the axial direction of the pump housing, and a flexible film covering the deformation hole is provided in the deformation hole; when the expansion tube returns from its initial shape to its expanded shape, it can stretch or unfold the flexible film circumferentially along the pump housing.

[0023] In some of these embodiments, the expansion tube is provided with a plurality of the deformation holes, and the plurality of deformation holes are arranged at intervals along the circumferential direction of the expansion tube; a deformation flap extending along the axial direction of the pump housing is formed between two adjacent deformation holes.

[0024] In some of these embodiments, the deformation hole has a first width extending along the circumferential direction of the pump housing, the deformation flap has a second width extending along the circumferential direction of the pump housing, and in the initial form of the expansion tube, the second width is greater than the first width; and / or, the outer diameter of the expansion tube in the initial form is the contracted outer diameter D 2a , and W≥0.25πD 2a .

[0025] In some of these embodiments, the expansion tube further has at least one of the following characteristics:

[0026] The number of the deformation flaps is 2 to 5;

[0027] The periphery of the flexible membrane is fixedly connected to the periphery of the deformation hole;

[0028] In the initial form of the expansion tube, the flexible membrane is folded in the deformation hole.

[0029] In some of these embodiments, the impeller includes a hub and blades provided on the hub, and the blades are located inside the expansion tube; wherein,

[0030] The deformation hole has a first length extending along the axial direction of the pump housing, the blade has a second length extending along the axial direction of the pump housing, the first length is greater than the second length, and both ends of the deformation hole extend beyond both ends of the blade;

[0031] and / or, the blade is completely received inside the expansion tube, and a first distance is provided between the proximal end of the blade and the proximal end of the expansion tube along the axial direction of the pump housing, and a second distance is provided between the distal end of the blade and the distal end of the expansion tube along the axial direction of the pump housing.

[0032] In some of these embodiments, the expansion tube includes a first pipe section, a second pipe section and a main pipe section connected between the first pipe section and the second pipe section; in the expanded form of the expansion tube, the diameter of the first pipe section gradually decreases along the direction from the distal end to the proximal end of the pump housing; the diameter of the second pipe section gradually decreases along the direction from the proximal end to the distal end of the pump housing.

[0033] In some of these embodiments, the blood pump further includes a driving unit, the driving unit includes a housing and a rotating shaft connected to the impeller; the pump housing further includes a proximal pipe connected to the proximal end of the expansion tube, the proximal pipe is fixedly connected to the housing, and the proximal pipe is provided with the proximal opening.

[0034] In some of these embodiments, the pump housing further has at least one of the following features:

[0035] The proximal tube is a non-deformable structure;

[0036] The proximal tube and the expansion tube are of an integral structure;

[0037] When the expansion tube is in its initial form, its outer diameter is the contracted outer diameter D 2a , and the contracted outer diameter D 2a is the same as the outer diameter of the proximal tube;

[0038] When the expansion tube is in its expanded form, its outer diameter is the expanded outer diameter D 2b , and the ratio of the expanded outer diameter D 2b to the outer diameter of the proximal tube is 1.1 to 1.5.

[0039] In some of these embodiments, the pump housing assembly further includes an intubation assembly having a blood flow path; the pump housing further includes a distal tube connected to the distal end of the expansion tube, and the distal tube is fixedly connected to the proximal end of the intubation assembly.

[0040] In some of these embodiments, the pump housing further has at least one of the following features:

[0041] The distal tube is a non-deformable structure;

[0042] The distal tube and the expansion tube are of an integral structure;

[0043] When the expansion tube is in its initial form, its outer diameter is the contracted outer diameter D 2a , and the contracted outer diameter D 2a is the same as the outer diameter D of the distal tube 7 ;

[0044] When the expansion tube is in its expanded form, its outer diameter is the expanded outer diameter D 2b , and the ratio of the expanded outer diameter D 2b to the outer diameter D of the distal tube 7 is 1.1 to 1.5.

[0045] In the above-mentioned blood pump, since the expansion tube of the pump housing includes a first shape memory material, the expansion tube has an initial shape and an expanded shape that expands relative to its initial shape; the first shape memory material can deform under blood temperature conditions, and the expansion tube expands from the initial shape to the expanded shape, thereby increasing the inner diameter of the expansion tube. In this way, the blood pump can appropriately reduce the initial width of the radial gap between the inner wall surface of the expansion tube and the impeller in the initial state, or even not reserve the radial gap, so that the blood pump can use an impeller with a large diameter to replace the traditional impeller with a small diameter. The large-diameter impeller has higher hydraulic performance, so the blood pump can appropriately reduce the rotation speed of the impeller to reduce the degree of collision between the impeller blades and blood cells, thereby reducing blood cell damage and effectively reducing hemolysis.

[0046] Of course, the blood pump can also use a traditional impeller with a small diameter as usual. After the expansion tube expands from the initial shape to the expanded shape, the width of the radial gap between the impeller and the inner wall of the expansion tube becomes larger, so that blood cells can pass smoothly and quickly through the radial gap. This can greatly reduce the damage of the impeller to the blood cells passing through the radial gap and reduce hemolysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a structural diagram of the pump housing of the blood pump in the initial state according to the first embodiment of the present application.

[0048] Figure 2 for Figure 1 Schematic diagram of the structural breakdown of the blood pump provided.

[0049] Figure 3 for Figure 1 A schematic longitudinal section of a blood pump is provided.

[0050] Figure 4 for Figure 1 A cross-sectional schematic diagram of a blood pump is provided.

[0051] Figure 5 for Figure 1 An axonometric view of the pump housing of a blood pump is provided.

[0052] Figure 6 This is a structural diagram of the pump housing of the blood pump according to the first embodiment of the present application in an expanded state.

[0053] Figure 7 for Figure 6 Schematic diagram of the structural breakdown of the blood pump provided.

[0054] Figure 8 for Figure 6 A schematic longitudinal section of a blood pump is provided.

[0055] Figure 9 forFigure 6 Schematic cross-sectional view of the provided blood pump.

[0056] Figure 10 For Figure 6 Axonometric view of the pump housing of the provided blood pump.

[0057] Figure 11 Schematic diagrams of the expansion tubes of the blood pump in the first embodiment of the present application accommodating large-diameter rigid impellers in the initial and expanded forms respectively.

[0058] Figure 12 Schematic diagrams of the expansion tubes of the blood pump in the second embodiment of the present application accommodating small-diameter rigid impellers in the initial and expanded forms respectively.

[0059] Figure 13 Schematic diagrams of the expansion tubes of the blood pump in the third embodiment of the present application accommodating deployable impellers in the initial and expanded forms respectively.

[0060] Figure 14 Structural diagram of the pump housing of the blood pump in the third embodiment of the present application in the initial form.

[0061] Figure 15 For Figure 14 Exploded schematic view of the structure of the provided blood pump.

[0062] Figure 16 For Figure 14 Schematic longitudinal-sectional view of the provided blood pump.

[0063] Figure 17 For Figure 14 Schematic cross-sectional view of the provided blood pump.

[0064] Figure 18 For Figure 14 Axonometric view of the pump housing of the provided blood pump.

[0065] Figure 19 For Figure 18 Front view of the provided pump housing.

[0066] Figure 20 Structural diagram of the pump housing of the blood pump in the third embodiment of the present application in the expanded form.

[0067] Figure 21 For Figure 20 Exploded schematic view of the structure of the provided blood pump.

[0068] Figure 22 For Figure 20 Schematic longitudinal-sectional view of the provided blood pump.

[0069] Figure 23 For Figure 20 Schematic cross-sectional view of the provided blood pump.

[0070] Figure 24 The Figure 20 axonometric view of the pump housing of the provided blood pump.

[0071] Figure 25 The Figure 24 front view of the provided pump housing.

[0072] Figure 26 The Figure 25 front view of the provided pump housing along I-I.

[0073] Figure 27 Schematic diagram of the initial insertion of the blood pump of the present application into the body.

[0074] Figure 28 Schematic diagram of the blood pump of the present application being pushed to the target position in the body.

[0075] Figure 29 Manufacturing process of the pump housing of the blood pump provided by the present application. Detailed implementation manners

[0076] To make the above objects, features, and advantages of the present application more obvious and understandable, the following describes the detailed implementation manners of the present application in conjunction with the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0077] In the description of the present application, it should be understood that if terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or positional relationship indicated by these terms is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present application.

[0078] In addition, if the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "a plurality" appears, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0079] In this application, unless otherwise clearly specified and defined, if terms such as "installed", "connected", "joined", "fixed", etc. appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0080] In this application, unless otherwise clearly specified and defined, if there is a description such as a first feature being "on" or "under" a second feature, the meaning can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher horizontal level than the second feature. The first feature being "under", "beneath" and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower horizontal level than the second feature.

[0081] It should be noted that if an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there can also be an intermediate element. If an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. If so, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in this application are only for the purpose of illustration and do not represent the only implementation.

[0082] It should be noted that the "distal end" and "proximal end" throughout the text are only for indicating the relative position relationship. The "distal end" of a component refers to the end of the component that first enters the patient's body compared to the other end during normal operation and / or the end that is farther from the operator, while the "proximal end" refers to the end that enters the patient's body later compared to the other end and / or the end that is closer to the operator.

[0083] In the related art, an impeller is disposed inside a pump housing of a blood pump. Driving the impeller to rotate can drive the blood to flow. When the blood pump is operating, during the process of blood flowing through the impeller, hemolysis problems are likely to occur, resulting in some potential safety hazards for the blood pump.

[0084] Therefore, this application studies this problem and analyzes its causes. Through research, it is found that a radial gap is usually reserved between the inner wall surface of the pump housing and the impeller. This radial gap allows the impeller to rotate freely and prevents the impeller from contacting the inner wall surface of the pump housing when rotating. On the one hand, if the diameter of the impeller is designed to be relatively large, the reserved radial gap will be relatively small. When blood cells flow through this radial gap, it is not smooth and they are more likely to collide with the blades of the impeller and be damaged, thus causing hemolysis. On the other hand, if the radial gap is designed to be relatively large, then the diameter of the impeller has to be reduced. However, the hydraulic performance of a small-diameter impeller is poor (i.e., the flow rate is small). In this case, if the requirements for the hydraulic performance of the blood pump are to be met, the rotational speed of the impeller must be increased. However, when the rotational speed of the impeller increases, the degree of collision of the impeller with blood cells will intensify, resulting in an increase in hemolysis.

[0085] See Figure 1 、 Figure 27 and Figure 28 In view of the above situation, this application provides a blood pump 10, aiming to be able to reduce the hemolysis rate of the blood pump 10 and improve the safety performance of the blood pump 10. The blood pump 10 is mainly applicable to being pushed into the left ventricle 40 via the aorta 20 to assist the left heart in pumping blood. Of course, in other embodiments, it can also be applied to being pushed into the pulmonary artery via the right ventricle to assist the right heart in pumping blood. The following will introduce each embodiment of the blood pump of this application in detail.

[0086] Figures 1 to 11 Figure 1 shows the first embodiment of the blood pump of this application. See Figures 1 to 3 , the blood pump 10 of the first embodiment includes a pump housing 100 and an impeller 400A. The pump housing 100 is provided with a proximal opening 101; the impeller 400A is rotatably disposed inside the pump housing 100.

[0087] See Figure 3 、 Figure 27 and Figure 28 , when the blood pump 10 is pushed into the left ventricle 40 via the aorta 20, the distal end of the blood pump 10 is located inside the left ventricle 40, and the proximal opening 101 of the blood pump 10 is located inside the aorta 20. When driving the impeller 400A to rotate, the blood in the left ventricle 40 flows into the interior of the pump housing 100 from the distal end of the blood pump 10 and flows out of the proximal opening 101 into the aorta 20 to assist the blood pump in pumping blood.

[0088] See Figures 1 to 3, the impeller 400A includes a hub 410 and blades 420 disposed on the hub 410. The number of the blades 420 can be two, three, or four. When the impeller 400A rotates, a certain radial clearance 102 needs to be reserved between the blades 420 of the impeller 400A and the inner wall surface 103 of the pump housing 100. This radial clearance 102 allows the impeller 400A to rotate within the pump housing 100 without contacting the inner wall surface 103 of the pump housing 100.

[0089] In this embodiment, the impeller 400A is a non-expandable rigid impeller. That is, the impeller 400A has a constant shape, and the shape of the impeller 400A will not deform before the blood pump 10 enters the patient and after it enters the patient's body. Of course, in other embodiments (such as the third embodiment described later), the impeller 400A can be replaced with an expandable impeller 400A.

[0090] See Figure 1 and Figure 2 , Figure 6 and Figure 7 , the pump housing 100 includes an expansion tube 110, and the impeller 400A is received inside the expansion tube 110. The expansion tube 110 includes a first shape memory material, such that the expansion tube 110 has an initial form and an expanded form that expands relative to its initial form. Among them Figure 1 and Figure 2 show the expansion tube 110 in the initial form; Figure 6 and Figure 7 show the expansion tube 110 in the expanded form.

[0091] The first shape memory material can deform under the temperature condition of blood temperature, so that the expansion tube 110 expands from the initial form to the expanded form. After the expansion tube 110 expands from the initial form to the original expanded form at blood temperature, the inner diameter of the expansion tube 110 can become larger.

[0092] It can be understood that after the first shape memory material undergoes plastic deformation through heat treatment, it can automatically return to the form before heat treatment under the stimulation of an expected temperature (such as blood temperature). Therefore, for the expansion tube 110 including the first shape memory material, the expanded form of the expansion tube 110 is the form before heat treatment and is the prefabricated working form; when the expansion tube 110 in the expanded form undergoes heat treatment, it undergoes plastic deformation, and the diameter of the expansion tube 110 shrinks, so that the expansion tube 110 deforms from the expanded form to the initial form. This initial form is the form presented by the expansion tube 110 during the period from after heat treatment to before entering the patient's body. When the expansion tube 110 in the initial form is heated to the expected temperature (such as blood temperature), the expansion tube 110 automatically expands from the initial form to the expanded form (i.e., the working form).

[0093] Among them, the blood temperature refers to the blood temperature of a normal human body, such as 36°C to 37.5°C. However, in order to ensure that the expansion tube 110 can also expand normally in the bodies of some patients with low or high blood temperatures, the temperature at which the first shape memory material deforms is 34°C to 39°C, so that the expansion tube 110 can be set to expand from the initial form to the expanded form in the temperature range of 34°C to 39°C.

[0094] In addition, the first shape memory material can be a shape memory polymer or a shape memory alloy. The shape memory polymer can achieve transformation temperature control by adjusting the molecular structure. The shape memory polymer can be PLC, PU, PLA, etc. The shape memory alloy can achieve transformation temperature control by adjusting the alloy composition. The shape memory alloy can be a nickel-containing alloy, a titanium-containing alloy, etc. It should be noted that the first shape memory material should be selected as a material that is harmless to the human body and can be applied to the human body. Specifically, in this embodiment, the expansion tube 110 is made of a shape memory alloy, such as a nickel-titanium alloy.

[0095] See Figure 4 and Figure 9 After the expansion tube 110 expands from the initial form to the expanded form, the inner diameter of the expansion tube 110 increases, that is, the inner diameter of the expansion tube 110 in the expanded form is greater than the inner diameter of the expansion tube 110 in the initial form. Denote the inner diameter of the expansion tube 110 in the initial form as the contraction inner diameter D 1a , and denote the inner diameter of the expansion tube 110 in the expanded form as the expansion inner diameter D 1b , then D 1b > D 1a .

[0096] When manufacturing the blood pump 10, the expansion tube 110 of the pump housing 100 can be prefabricated into the expected expanded form first; then the pump housing 100 is heat-treated to make the expansion tube 110 undergo plastic deformation and shrink into the initial form; finally, the expansion tube 110 is assembled to the blood pump 10 in the initial form. In other embodiments, the expansion tube 110 can also be assembled to the blood pump 10 in the expanded form first; then the expansion tube 110 is heat-treated to make the expansion tube 110 undergo plastic deformation and shrink into the initial form.

[0097] See Figure 11 When the expansion tube 110 is in the initial form, denote the width of the radial clearance 102 between the inner wall surface 103 of the expansion tube 110 and the impeller 400A as the initial width K 1 ; when the expansion tube 110 is in the expanded form, denote the width of the radial clearance 102 between the inner wall surface 103 of the expansion tube 110 and the impeller 400A as the final width K 2When the expansion tube 110 expands from its initial shape to its expanded shape, the inner diameter of the expansion tube 110 increases; while the diameter of the impeller 400A remains unchanged, the width of the radial clearance 102 will increase, that is, K 2 > K 1 Thus, the initial width K of the radial clearance 102 that the blood pump 10 needs to reserve 1 can be smaller, or even can be equal to 0 mm, so that the blood pump can use an impeller 400A with a large diameter D 3 to replace the traditional impeller 400B with a small diameter D 4 (such as Figure 12 ). And the impeller 400A with a large diameter D 3 has higher hydraulic performance, then the blood pump 10 can appropriately reduce the rotation speed of the impeller 400A to reduce the degree of collision between the blades 420 of the impeller 400A and blood cells, thereby reducing blood cell damage and effectively reducing hemolysis.

[0098] See Figure 27 , when the blood pump 10 is pushed into the body through the wound, the expansion tube 110 enters the patient's body in its initial shape. See Figure 28 , when the blood pump 10 is pushed to the left ventricle 40 via the aorta 20, the distal end of the blood pump 10 is pushed into the left ventricle 40, and the expansion tube 120 and the proximal opening 101 are both received in the aorta 20. After the expansion tube 110 contacts the blood in the body, the heat of the blood gradually heats the expansion tube 110, and the expansion tube 110 gradually expands after reaching the blood temperature, so that the expansion tube 110 automatically returns from its initial shape to its expanded shape, thereby increasing the inner diameter of the expansion tube 110 and the width of the radial clearance 102 from the initial width K 1 increases to the final width K 2 . It can be understood that the initial width K 1 is greater than or equal to 0 mm; the final width K 2 is greater than the initial width K 1 . As for the size of the final width K 2 , as long as the final width K 2 can allow the impeller 400A to rotate without easily contacting the inner wall surface of the expansion tube 110.

[0099] It can be seen from this that in the blood pump 10 of the present application, the expansion tube 110 of the pump housing 100 includes a first shape memory material, so that the expansion tube 110 has an initial shape and an expanded shape that expands relative to its initial shape; and the first shape memory material can deform under blood temperature conditions, so that the expansion tube 110 expands from its initial shape to its expanded shape, thereby increasing the inner diameter of the expansion tube 110. Thus, the initial width K of the radial clearance 102 that the blood pump 10 needs to reserve 1 can be smaller, or even can be equal to 0 mm, so that the blood pump 10 can use an impeller 400A with a large diameter D3 with the impeller 400A to replace the traditional impeller with a small diameter D 4 of the impeller 400B. And the impeller 400A with a large diameter D 3 has higher hydraulic performance, then the blood pump 10 can appropriately reduce the rotational speed of the impeller 400A to reduce the degree of collision between the blades 420 of the impeller 400A and blood cells, thereby reducing blood cell damage and effectively reducing hemolysis.

[0100] As Figure 11 shown in (a) below, in the initial state of the expansion tube 110, the width of the radial gap 102 between the inner wall surface 103 of the expansion tube 110 and the impeller 400A (i.e., the initial width K 1 ) can be set to K 1 < 0.08 mm. At this time, the impeller 400A has not started to work, so although K 1 is small, it does not affect the impeller 400A.

[0101] Optionally, the initial width K 1 is set to 0 ≤ K 1 ≤ 0.06 mm. The initial width K 1 can be but is not limited to 0 mm, 0.01 mm, 0.02 mm, 0.03 mm, 0.05 mm, 0.06 mm, etc. When K 1 = 0 mm, the diameter D 3 of the impeller 400A is the largest; the diameter D 3 of the impeller 400A is equal to the inner diameter of the expansion tube 110 in the initial state (i.e., the contracted inner diameter D 1a ), that is, D 3 = D 1a . Therefore, for the rigid impeller 400A, the maximum value of the diameter D 3 of the impeller 400A can be taken to be the same as the inner diameter of the expansion tube 110 in the initial state (i.e., the contracted inner diameter D 1a ).

[0102] As Figure 11 shown in (a) and (b) below, after the expansion tube 110 expands from the initial state to the expanded state, the width of the radial gap 102 increases from the initial width K 1 to the final width K 2 , obviously K 2 > K 1 . The final width K 2 only needs to satisfy the safe and stable rotation of the impeller 400A. For example, the final width K 2 is set to 0.08 mm to 0.3 mm, that is, 0.08 mm ≤ K 2 ≤ 0.3 mm. Optionally, 0.1 mm ≤ K 2 ≤ 0.3 mm. The final width K2 The value of

[0103] Since the expansion tube 110 includes the first shape memory material, the first shape memory material can deform under the blood temperature condition, so that the expansion tube 110 expands to the expanded form in the initial form. That is to say, the first shape memory material deforms through temperature stimulation. Therefore, when the first shape memory material is not subjected to the corresponding temperature stimulation, the first shape memory material will not deform. Based on this, when the expansion tube 110 in the initial form is not subjected to thermal stimulation (i.e., blood temperature stimulation), the expansion tube 110 can maintain the shape contracted relative to the expanded form without external force, that is, the initial form of the expansion tube does not require external force to maintain. The shape of the expansion tube 110 in the initial form allows the expansion tube 110 to enter the body smoothly. In this way, the expansion tube 110 can maintain the shape contracted relative to the expanded form without applying external force extrusion by means of the sheath. Subsequently, after the expansion tube 110 is stimulated by the blood temperature, the expansion tube 110 gradually expands, and when the expansion tube 110 reaches the target position (such as one end of the aorta 20 adjacent to the aortic valve 30) within the expected time, it can expand to the expanded form.

[0104] It should be noted that under normal circumstances, when the expansion tube 110 has not reached the target position before the expected time, the expansion tube 110 is in the initial form or the incompletely expanded form, and the outer diameter of the expansion tube 110 remains small, which is convenient for the expansion tube 110 to be advanced in the body; until the expansion tube 110 reaches the target position at the expected time, the expansion tube 110 will fully expand to the expanded form, so that the width of the radial gap 102 changes from the initial width K 1 to the final width K 2 .

[0105] However, in some unexpected situations, such as the operator of the blood pump 10 having insufficient experience or the resistance of the pushing path in the patient's body being relatively large, these factors may cause the time for pushing the blood pump 10 into the body to be prolonged. Then, the expansion tube 110 may expand to the expanded form in advance before reaching the target position, and the outer diameter of the expansion tube 110 is relatively large, which may affect the subsequent advancement of the expansion tube 110 towards the target position.

[0106] To reduce the occurrence of the above situation, the maximum outer diameter of the expansion tube 110 in the expanded state can be set to allow the expansion tube 110 to pass through the narrowest position on the in-vivo pushing path. In this way, when an unexpected situation causes the extension of the time for the blood pump 10 to be pushed into the body, if the expansion tube 110 is fully inflated to the expanded state before reaching the aorta 20, then since the maximum outer diameter of the expansion tube 110 in the expanded state allows the expansion tube 110 to pass through the narrowest position on the in-vivo pushing path, the expansion tube 110 can also smoothly pass through the narrowest position on the in-vivo pushing path in the expanded state. Moreover, when the blood pump 10 is withdrawn from the patient's body, the expansion tube 110 can also smoothly pass through the narrowest position on the in-vivo pushing path in the expanded state, so that it is not necessary to push an auxiliary sheath into the body to wrap and squeeze the expansion tube 110 to reduce its outer diameter.

[0107] It can be understood that the narrowest positions on the in-vivo pushing paths of different patients are different, such as the elderly and children, obese patients or emaciated patients. Therefore, the maximum outer diameter of the expansion tube 110 in the expanded state should be reasonably designed according to the narrowest position on the in-vivo pushing path of the actual patient to be applied, which will not be listed in detail here.

[0108] Of course, in other embodiments, to prevent the expansion tube 110 from being prematurely inflated to the expanded state before reaching the target position, an auxiliary sheath can also be used to wrap the expansion tube 110, and the auxiliary sheath and the expansion tube 110 are pushed to the target position together, and then the auxiliary sheath is withdrawn from the body. After the auxiliary sheath is separated from the expansion tube 110, the expansion tube 110 is inflated to the expanded state.

[0109] In addition, it is also worth mentioning that since the expansion tube 110 is received in the aorta 20 in the expanded state, the expansion tube 110 does not cross the aortic valve 30. Thus, when the blood pump 10 enters or is withdrawn from the patient's body, the expanded expansion tube 110 does not need to pass through the aortic valve 30, so that the expansion tube 110 is not likely to squeeze and expand the aortic valve 30, thereby reducing the damage to the aortic valve 30 caused by the blood pump 10.

[0110] Figure 12 The second embodiment of the blood pump of the present application is shown. The difference between this second embodiment and the above first embodiment is that: the blood pump 10 of the second embodiment normally uses a traditional impeller 400B with a small diameter D 4 The diameter D of the impeller 400B 4 is smaller than the diameter D of the impeller 400A 3 , that is, D 4 <D 3 . The impeller 400B is also a non-expandable rigid impeller. That is, the impeller 400B has a constant shape, and the shape of the impeller 400B will not deform before the blood pump enters the patient and after it enters the patient's body.

[0111] Due to the diameter D of the impeller 400B 4 being small (D 4 <D 3 ), in the initial form of the expansion tube 110, the initial width K of the radial gap 102 1 is not 0 mm, that is, K 1 >0 mm. After the expansion tube 110 expands from the initial form to the expanded form, the width of the radial gap 102 increases from the initial width K 1 to the final width K 2 . Obviously, K 2 >K 1 . Since the width of the radial gap 102 becomes larger, when the impeller 400B is subsequently started to rotate and work, blood cells can smoothly pass through the radial gap 102 quickly, and the blood cells will not be congested in the radial gap 102. Furthermore, the blood cells are not easily scratched by the blades 420 of the impeller 400B, and hemolysis can also be reduced.

[0112] Thus, it can be seen that in the blood pump 10 of the present application, the expansion tube 110 of the pump housing 100 includes a first shape memory material, so that the expansion tube 110 has an initial form and an expanded form that expands relative to its initial form; and the first shape memory material can deform under blood temperature conditions, so that the expansion tube 110 expands from the initial form to the expanded form, thereby increasing the inner diameter of the expansion tube 110. In this way, even if the blood pump 10 normally uses a traditional impeller 400B with a small diameter D 4 , after the expansion tube 110 expands from the initial form to the expanded form, the width of the radial gap 102 between the impeller 400B and the inner wall surface 103 of the expansion tube 110 can be increased, so that blood cells can smoothly pass through the radial gap 102 quickly, and the blood cells will not be congested in the radial gap 102. In this way, the damage to the blood cells passing through the radial gap 102 by the impeller 400B can be greatly reduced, and hemolysis can be reduced.

[0113] It can be seen from the first embodiment and the second embodiment that by setting the expansion tube 110 to include a first shape memory material, so that the expansion tube 110 has an initial form and an expanded form that expands relative to its initial form, and the first shape memory material can deform under blood temperature conditions, so that the expansion tube 110 expands from the initial form to the expanded form, the blood pump 10 can reduce the damage to blood cells and reduce hemolysis whether it uses a rigid impeller 400A with a large diameter D 3 or a rigid impeller 400B with a small diameter D 4 .

[0114] As described above, the impeller 400B in the second embodiment is also a non-expandable rigid impeller. That is, the impeller 400B has a constant shape, and the shape of the impeller 400B will not be deformed by the blood temperature before the blood pump 10 enters the patient and after it enters the patient's body. Preferably, the shape of the expansion tube 110 in its initial form is tubular, so that the expansion tube 110 can accommodate the rigid impeller 400B.

[0115] As Figure 12 shown in (a) therein, in this embodiment, the initial width K of the radial clearance 102 between the inner wall surface 103 of the expansion tube 110 and the impeller 400B 1 can be set to at least 0.08 mm. Such as the initial width K 1 can be 0.08 mm to 0.2 mm, that is, 0.08 mm ≤ K 1 ≤ 0.2 mm. The value of the initial width K 1 can be but is not limited to 0.09 mm, 0.1 mm, 0.12 mm, 0.15 mm, 0.18 mm, 0.2 mm.

[0116] Under normal circumstances, when the expansion tube 110 reaches the target position (such as one end of the aorta 20 adjacent to the aortic valve 30), it can be normally expanded to the expanded form, so that the width of the radial clearance 102 changes from the initial width K 1 to the final width K 2 . If an accident occurs when the expansion tube 110 reaches the target position, such as the expansion tube 110 does not expand or the expansion amplitude is small, this will cause the expansion tube 110 not to fully return to the expanded form. At this time, since the impeller 400B is a rigid impeller and the width of the radial clearance 102 is at least 0.08 mm, even if the expansion tube 110 does not return to the expanded form, the initial width K of the radial clearance 102 1 is also sufficient for the impeller 400B to rotate stably in the expansion tube 110 and allow blood to flow through the expansion tube 110, without causing the entire blood pump 10 to become paralyzed and unable to work.

[0117] As Figure 12 shown in (b) therein, in the expanded form of the expansion tube 110, the final width K of the radial clearance 102 between the inner wall surface 103 of the expansion tube 110 and the impeller 400B 2 is greater than 0.08 mm, that is, K 2 > 0.08 mm. In the case of K 2 > K 1 , the final width K 2 can be set to 0.08 mm < K 2 ≤ 0.3 mm. The final width K 2The value of 2 K may be, but is not limited to, 0.09 mm, 0.1 mm, 0.12 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.25 mm, 0.28 mm, 0.3 mm, etc. Preferably, 0.1 mm < K

[0118] Figures 13 to 26 shows the third embodiment of the blood pump of the present application. Refer to Figure 13 , in the third embodiment, the difference between the third embodiment and the first embodiment is that the impeller 400C adopted by the blood pump 10 is a deformable impeller. Specifically, the impeller 400C includes a second shape memory material, so that the impeller 400C has an initial shape and an expanded shape expanded relative to its initial shape. The second shape memory material can be deformed under the blood temperature condition, so that the impeller 400C expands from the initial shape to the expanded shape.

[0119] It can be understood that after the second shape memory material undergoes plastic deformation through heat treatment, it can automatically return to the shape before heat treatment when heated to an expected temperature (such as blood temperature). Therefore, for the impeller 400C including the second shape memory material, the expanded shape of the impeller 400C is the shape before heat treatment and also the prefabricated working shape; the impeller 400C in the expanded shape undergoes plastic deformation after heat treatment, and the blades 420 of the impeller 400C contract or fold, so that the impeller 400C deforms from the expanded shape to the initial shape. This initial shape is also the shape presented by the impeller 400C during the period from after heat treatment to before entering the patient's body. When the impeller 400C in the initial shape is heated to an expected temperature (such as blood temperature), the impeller 400C automatically expands from the initial shape to the expanded shape (i.e., the working shape).

[0120] Among them, the blood temperature generally refers to the blood temperature of a normal human body, such as 36°C to 37.5°C. However, in order to ensure that the impeller 400C can also expand normally in the bodies of some patients with relatively low or high blood temperatures, the temperature at which the second shape memory material deforms is 34°C to 39°C, so that the impeller 400C can expand from the initial shape to the expanded shape at a blood temperature in the range of 34°C to 39°C.

[0121] The second shape memory material may be the same as or different from the first shape memory material. The second shape memory material may be a shape memory polymer or a shape memory alloy. The shape memory polymer can achieve transformation temperature control by adjusting the molecular structure. The shape memory polymer may be PLC, PU, PLA, etc. The shape memory alloy can achieve transformation temperature control by adjusting the alloy composition. The shape memory alloy may be a nickel-containing alloy, a titanium-containing alloy, etc. It should be noted that the first shape memory material should be selected as a material that is harmless to the human body and can be applied to the human body. Specifically, in this embodiment, the impeller 400C is made of a shape memory alloy, such as a nickel-titanium alloy. This can make the impeller 400C have a certain hardness and ensure that the impeller 400C can rotate stably.

[0122] See Figure 14 and Figure 15 , and Figure 20 and Figure 21 , after the impeller 400C expands and recovers from the initial form to the original expanded form, the blades 420 of the impeller 400C unfold, making the diameter of the impeller 400C larger.

[0123] See Figure 13 in (a) or Figure 17 , when the impeller 400C is in the initial form, the diameter is denoted as the initial diameter D 5a . See Figure 13 in (b) or Figure 23 , when the impeller 400C is in the expanded form, the diameter is denoted as the working diameter D 5b , then there is D 5b > D 5a . This can make the impeller 400C obtain a larger diameter, so that the impeller 400C has higher hydraulic performance. In this case, within a certain range, reducing the rotational speed of the impeller 400C can also meet the requirements of the blood pump 10 for hydraulic performance. Since the rotational speed of the impeller 400C decreases, the blades 420 of the impeller 400C will not collide and damage blood cells, effectively reducing hemolysis.

[0124] See Figures 14 to 16 , when the blood pump 10 is pushed into the body through the wound, both the expansion tube 110 and the impeller 400C enter the body in the initial form. See Figures 20 to 22, it is pushed through the aorta 20 into the left ventricle 40, so that the distal end of the blood pump 10 is located within the left ventricle 40, while the expansion tube 120 and the proximal opening 101 are both received within the aorta 20. After the expansion tube 110 and the impeller 400C come into contact with the blood, the heat of the blood gradually heats the impeller 400C and the expansion tube 110. When the impeller 400C and the expansion tube 110 reach the blood temperature, they gradually expand, causing the impeller 400C and the expansion tube 110 to automatically return from the initial form to the expanded form. As a result, the diameter of the impeller 400C increases, and the inner diameter of the expansion tube 110 also increases, enabling the expansion tube 110 to accommodate the impeller 400C after the blades 420 are deployed.

[0125] Since the impeller 400C includes a second shape memory material, the second shape memory material can deform under blood temperature conditions, causing the impeller 400C to expand from the initial form to the expanded form. That is to say, the second shape memory material deforms through temperature stimulation. Therefore, when the second shape memory material is not subjected to the corresponding temperature stimulation, the second shape memory material will not deform. Based on this, when the impeller 400C in the initial form is not subjected to the corresponding temperature (such as blood temperature) stimulation, the impeller 400C can maintain the folded shape relative to the expanded form without external force. That is, the initial form of the impeller 400C does not require external force to maintain. The diameter of the shape of the impeller 400C in the initial form can be smaller, as long as it can be accommodated within the expansion tube 110 in the initial form. In this way, the impeller 400C can maintain the common folded form relative to the expanded form without the need for external force extrusion by means of a sheath. Subsequently, after the impeller 400C is stimulated by the blood temperature, the impeller 400C can gradually expand to the expanded form.

[0126] It can be understood that when the expansion tube 110 and the impeller 400C are both in the initial form, the initial width K of the radial clearance 102 between the inner wall surface 103 of the impeller 400C and the expansion tube 110 1 can be 0 mm or greater than 0 mm, that is, K 1 ≥0 mm. After the expansion tube 110 and the impeller 400C return to the expanded form, the width of the radial clearance 102 increases from the initial width K 1 to the final width K 2 , and the final width K 2 only needs to allow the impeller 400C to rotate stably without contacting the inner wall surface 103 of the expansion tube 110.

[0127] In particular, when the initial width K 1 is 0 mm, then after the expansion tube 110 and the impeller 400C return to the expanded form, the working diameter D of the impeller 400C 5a will be greater than the contracted inner diameter D of the expansion tube 110 in the initial form 1a, so that the impeller 400C can obtain a larger diameter, greatly improving the hydraulic performance of the impeller 400C. Furthermore, when the hydraulic performance requirements of the blood pump 10 are met, the rotational speed of the impeller 400C can be reduced, making the blades 420 of the impeller 400C less likely to collide and damage blood cells, effectively reducing hemolysis. Therefore, optionally, when the expansion tube 110 is in its initial form, it has a contracted inner diameter D 1a , the initial diameter D of the impeller 400C 5a is greater than or equal to the contracted inner diameter D 1a , that is, D 5a ≥D 1a .

[0128] Optionally, when the expansion tube 110 is in its expanded form, the width K of the radial gap 102 between the inner wall surface 103 of the expansion tube 110 and the impeller 400C 2 can be 0.08 mm to 0.3 mm, that is, 0.08 mm ≤ K 2 ≤ 0.3 mm. Alternatively, 0.1 mm ≤ K 2 ≤ 0.3 mm. The value of K 2 can be, but is not limited to, 0.09 mm, 0.1 mm, 0.12 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.25 mm, 0.28 mm, 0.3 mm, etc.

[0129] See Figures 14 to 16 , the pump housing 100 further includes a proximal tube 120. The proximal tube 120 is connected to the proximal end of the expansion tube 110. The proximal tube 120 is provided with a proximal opening 101. The proximal tube 120 is a non-deformable structure. The proximal tube 120 has a certain hardness. That is, after the proximal tube 120 enters the body, it will not be deformed by the blood. This can make the proximal tube 120 have a relatively high hardness, so as to improve the firmness of the connection between the proximal tube 120 and the driving unit 500, making the connection between the two less likely to loosen and fall off.

[0130] Preferably, the working diameter D of the impeller 400C 5a is greater than the inner diameter of the proximal tube 120. This can enable the impeller 400C to obtain a larger diameter, so that the hydraulic performance of the impeller 400C is relatively high. When the hydraulic performance requirements of the blood pump 10 are met, the rotational speed of the impeller 400C can be reduced to a greater extent, thereby reducing the damage to blood cells caused by the rotation of the impeller 400C.

[0131] See Figures 14 to 16, the pump housing 100 further includes a distal tube 130. The distal tube 130 is connected to the distal end of the expansion tube 110 and is a non-deformable structure. That is, the distal tube 130 will not be deformed by blood after entering the body. The distal tube 130 can be connected to an intubation assembly 200 having a distal opening 201. Of course, in other embodiments, the distal opening 201 can also be directly provided on the distal tube 130.

[0132] Preferably, the initial diameter D 5a is greater than the inner diameter of the distal tube 130. This can enable the impeller 400C to obtain a larger diameter, so that the hydraulic performance of the impeller 400C is higher. When the hydraulic performance requirements of the blood pump 10 are met, the rotational speed of the impeller 400C can be greatly reduced, thereby reducing the damage to blood cells caused by the rotation of the impeller 400C.

[0133] In this embodiment, the proximal tube 120 and the distal tube 130 are located on the same cylindrical tube, so the proximal tube 120 and the distal tube 130 have the same inner diameter and the same outer diameter.

[0134] In the first embodiment of the blood pump as shown in Figures 1 to 11 , the second embodiment of the blood pump as shown in Figure 12 , or the third embodiment of the blood pump as shown in Figures 13 to 26 , the blood pump 10 may further include any one of an intubation assembly 200, a catheter 300, and a driving unit 500. The pump housing 100 of the blood pump 10 may further include any one of a proximal tube 120 and a distal tube 130. The expansion tube 110 of the pump housing 100 may be provided with a deformation hole 11a, a deformation flap 11b, and a flexible membrane located at the deformation hole 11a. To avoid repetition, the following mainly takes the blood pump 10 of the embodiment shown in Figures 14 to 26 as an example for introduction; the blood pumps 10 of other embodiments can be implemented accordingly and will not be listed separately here.

[0135] Referring to Figures 14 to 15 and Figure 18 , the expansion tube 110 of the blood pump 10 is provided with a deformation hole 11a. The deformation hole 11a can enable the expansion tube 110 to have higher ductility, making it easier for the expansion tube 110 to be deformed by heat. During the process of the expansion tube 110 shrinking from the expanded form to the initial form through heat treatment, the deformation hole 11a provides a shrinking space for the wall of the expansion tube 110 to shrink. During the process of the expansion tube 110 expanding from the initial form to the expanded form under the influence of blood temperature, the deformation hole 11a can reduce the stress on the wall of the expansion tube 110, making it easier for the expansion tube 110 to expand by heat.

[0136] Referring to Figures 14 to 15 and Figure 18, the deformation hole 11a is elongated. The deformation hole 11a extends along the axial direction of the pump housing 100. Specifically, the deformation hole 11a has a first width W extending along the circumferential direction of the pump housing 100 1 , and a first length L extending along the axial direction of the pump housing 100 1 , the first length L 1 is greater than the first width W 1 . This can make the expansion tube 110 expand more easily along the radial direction to increase the diameter of the expansion tube 110. Of course, in other embodiments, the shape of the deformation hole 11a can also be oval, corrugated or slit-shaped, as long as the length direction of the deformation hole 11a is the same as the axial direction of the pump housing 100.

[0137] See Figures 16 to 18 , the number of the deformation holes 11a can be multiple. The multiple deformation holes 11a are arranged at intervals along the circumferential direction of the expansion tube 110. Of course, in other embodiments, there can be only one deformation hole 11a.

[0138] See Figures 16 to 18 , optionally, the multiple deformation holes 11a are arranged at equal intervals along the circumferential direction of the expansion tube 110. This can make the stress or strength of the tube walls on both sides of the deformation hole 11a of the expansion tube 110 be approximately the same. Thus, when the expansion tube 110 deforms, each position in the circumferential direction of the expansion tube 110 contracts or expands equally along the radial direction, ensuring that it is a circular tube before and after deformation, and further ensuring that there is a uniform radial gap 102 between the inner wall surface 103 of the expansion tube 110 and the impeller 400 along the circumferential direction. The number of the deformation holes 11a can be 2 to 6. Such as the number of the deformation holes 11a can be but not limited to 2, 3 or 4.

[0139] See Figures 16 to 18 , a flexible film covering the deformation hole 11a (not shown in the figure) is further provided in the deformation hole 11a. In the initial form of the expansion tube 110, the flexible film can be contracted or folded in the deformation hole 11a. When the expansion tube 110 returns from the initial form to the expanded form, the flexible film can be stretched or unfolded along the circumferential direction of the pump housing 100. Since the flexible film covers the deformation hole 11a, it can ensure that when the impeller 400C drives the blood to flow through the expansion tube 110 after the expansion tube 110 expands to the expanded form, a higher pressure can be formed in the expansion tube 110, which helps to improve the blood flow rate.

[0140] Preferably, the periphery of the flexible film is fixedly connected to the periphery of the deformation hole 11a, so that the flexible film is not easily detached. For example, the periphery of the flexible film and the periphery of the deformation hole 11a can be adhesively bonded or heat-melted. The periphery of the flexible film and the periphery of the deformation hole 11a are also hermetically connected to hermetically cover the deformation hole 11a, so that blood cannot flow out of the deformation hole 11a. The material of the flexible film can be Teflon material. For example, the flexible film can be selected as a PTFE film.

[0141] See Figures 16 to 18 , a deformation flap 11b extending along the axial direction of the pump housing 100 is formed between two adjacent deformation holes 11a. The deformation flap 11b is a part of the tube wall of the expansion tube 110. The deformation flap 11b has a second width W extending a certain distance along the circumferential direction of the pump housing 100 2 . In this embodiment, in the initial form of the expansion tube 110, the second width W of the deformation flap 11b 2 is greater than the first width W of the deformation hole 11a 1 , that is, W 2 >W 1 . Alternatively, the second width W 2 is greater than the radial thickness of the deformation flap 11b. This can enable the deformation flap 11b to obtain a larger cross-sectional area without occupying the radial space of the expansion tube 110, so that the deformation flap 11b, that is, the expansion tube 110, has a certain hardness. In this way, on the one hand, the expansion tube 110 can better maintain the shape of contracting relative to the expanded shape in the initial form, which is convenient for the expansion tube 110 to enter the body in the initial form and is not easily squeezed and collapsed by the internal tissues. On the other hand, when the expansion tube 110 is stimulated by the blood temperature, the expansion tube 110 slowly expands from the initial form to the expanded form, so as to avoid the expansion tube 110 expanding too quickly from the initial form to the expanded form after being stimulated by the blood temperature.

[0142] In addition, after the expansion tube 110 expands to the expanded form, the second width W of the deformation flap 11b 2 is also larger. Compared with the elastic metal wire in the shape of a silk thread, the deformation flap 11b of the expansion tube 110 in the expanded form has a greater hardness, so that the deformation flap 11b is not easily pressed flat and contacts the impeller 400C.

[0143] Optionally, the cross-section of the deformation flap 11b intercepted by a plane perpendicular to the central axis of the pump housing 100 is arc-shaped and non-circular. In addition, in the initial form of the expansion tube 110, the deformation flap 11b is a part of the tube wall of a cylindrical tube, and the second width W of the deformation flap 11b 2 remains constant along the axial direction of the pump housing 100. In the expanded form of the expansion tube 110, the second width W 2It gradually decreases from its middle part towards both ends in its axial direction, such that the deformable flap 11b presents a shape that is convex outward relative to the central axis of the pump housing 100, such as an arc shape, a boat shape, a crescent shape, etc.

[0144] Optionally, the number of deformable flaps 11b is 2 to 4. The number of deformable flaps 11b is the same as that of the deformation holes 11a. The number of deformable flaps 11b can be, for example, 2, 3, or 4. Since the plurality of deformation holes 11a are evenly spaced along the circumferential direction of the expansion tube 110, the second width W of the plurality of deformable flaps 11b 2 is substantially the same. When the expansion tube 110 deforms, the plurality of deformable flaps 11b contract or expand equally in the radial direction, so that the expansion tube 110 can be a cylindrical tube both before and after deformation, and further ensure that there is a uniform radial gap between the inner wall surface 103 of the expansion tube 110 and the impeller 400 along the circumferential direction.

[0145] See Figure 18 , when the expansion tube 110 is in its initial form, the outer diameter is denoted as the contraction outer diameter D 2a , the second width W of the deformable flap 11b 2 can be W 2 ≥0.25×π×D 2a . With such a setting, it can be ensured that the deformable flap 11b has a relatively large width, so that the tube wall of the expansion tube 110 has better strength, and it is ensured that the expansion tube 110 has high strength both before and after deformation and is not easily deformed by external forces.

[0146] Optionally, 0.25×π×D 2a ≤W 2 ≤0.5×π×D 2a .

[0147] See Figure 16 and Figure 18 , the expansion tube 110 includes a main pipe section 111 and a first pipe section 112, and the first pipe section 112 is connected to the proximal end of the main pipe section 11. See Figures 24 to 26 , when the expansion tube 110 is in the expanded form, the diameter of the first pipe section 112 gradually decreases in the direction from the distal end to the proximal end of the pump housing 100. In this way, the first pipe section 112 has a certain inclination. On the one hand, the inner wall surface 103 of the first pipe section 112 forms a conical guiding surface, which can guide the blood to flow from the main pipe section 111 to the first pipe section 112, so as to facilitate the blood to be discharged from the proximal opening 101 close to the first pipe section 112; on the other hand, the outer wall surface of the first pipe section 112 forms a conical diameter-reducing surface, which is beneficial to reducing the difficulty of the expansion tube 110 moving out of the blood vessel during the process of the blood pump 10 being withdrawn from the human body.

[0148] See Figure 16 and Figure 18, the expansion tube 110 may also include a main pipe section 111 and a second pipe section 113, and the second pipe section 113 is connected to the distal end of the main pipe section 11. See Figures 24 to 26 , in the expanded state of the expansion tube 110, the diameter of the second pipe section 113 gradually decreases in the direction from the proximal end to the distal end of the pump housing 100. In this way, the second pipe section 113 has a certain inclination. On the one hand, the inner wall surface 103 of the second pipe section 113 forms a conical guiding surface, which can guide the blood to enter the main pipe section 111 from the second pipe section 113, which is beneficial to improving the efficiency of the blood flowing to the impeller 400C; on the other hand, the outer wall surface of the second pipe section 113 forms a conical diameter-reducing surface, which is beneficial to moving the expansion tube 110 back and forth to finely adjust the position of the expansion tube 110 in the blood vessel after the blood pump 10 is pushed into the human body.

[0149] Of course, the expansion tube 110 may simultaneously have a main pipe section 111, a first pipe section 112 and a second pipe section 113.

[0150] See Figure 16 , the impeller 400C has a hub 410 and blades 420 arranged on the hub 410. The blades 420 have a second length L extending along the axial direction of the pump housing 100 2 ; the first length L 1 is greater than the second length L 2 (that is, L 1 > L 2 ), so that both ends of the deformation hole 11a extend beyond both ends of the blade 420. In this way, effective deformation can occur on the pipe walls of the expansion tube 110 and the blade 420 that are radially opposite to each other, ensuring that the radial gap 102 between any position on the outer edge of the blade 420 and the inner wall surface 103 of the expanded expansion tube 110 can be increased.

[0151] See Figure 16 , the blade 420 is completely received in the expansion tube 110. The proximal end of the blade 420 and the proximal end of the expansion tube 110 are axially spaced apart by a first distance △L along the pump housing 100 1 . Since the deformation amount of the first pipe section 112 of the expansion tube 110 is slightly smaller than the deformation amount of the main pipe section 111, by axially spacing the proximal end of the blade 420 and the proximal end of the expansion tube 110 by a first distance △L 1 , it is possible to avoid contact and interference between the blade 420 and the proximal end of the expansion tube 110.

[0152] Similarly, the distal end of the blade 420 and the distal end of the expansion tube 110 are axially spaced apart by a second distance △L along the pump housing 100 2 . Since the deformation amount of the second pipe section 113 of the expansion tube 110 is slightly smaller than the deformation amount of the main pipe section 111, by axially spacing the distal end of the blade 420 and the distal end of the expansion tube 110 by a second distance △L2 , it is possible to avoid the interference caused by the contact between the distal ends of the blade 420 and the expansion tube 110.

[0153] See Figures 14 to 16 , a proximal opening 101 is provided at the proximal end of the pump housing 100. A distal opening 201 is provided at the distal end of the blood pump 10. See Figure 28 , when the blood pump 10 is pushed into the left ventricle 40 via the aorta 20, the distal end of the distal opening 201 of the blood pump 10 is located within the left ventricle 40, while the proximal opening 101 is located within the aorta 20. The blood in the left ventricle 40 flows into the blood flow path within the pump housing 100 through the distal opening 201 of the blood pump 10 and flows out of the proximal opening 101 into the aorta 20 to assist the left heart in pumping blood.

[0154] See Figures 14 to 16 , the blood pump 10 further includes an intubation assembly 200. The intubation assembly 200 includes an intubation 210. The proximal end of the intubation 210 is fixedly connected to the distal end of the pump housing 100. The inner cavity of the intubation 210 forms a blood flow path. The intubation assembly 200 may further include a distal tube 220. The distal tube 220 is provided with a distal opening 201. Among them, the intubation 210 is a flexible tube and can be bent and deformed to adapt to the shape of the blood vessel. The intubation 210 can be a straight tube in the natural state or can be pre-shaped into a bent tube with a certain bending angle. After the blood pump 10 is pushed into the body, the intubation 210 extends across the aortic valve 30 through the aorta 20 into the left ventricle 40, so that the distal opening 201 is located within the left ventricle, while the expansion tube 110 and the proximal opening 101 of the pump housing 100 are both located within the aorta 20.

[0155] It can be understood that the distal tube 220 is not necessary. In other embodiments, the distal opening 201 can be directly opened at the distal end of the intubation 210. Of course, the blood pump 10 can also cancel the entire intubation assembly 200. Because after the expansion tube 110 of the pump housing 100 expands to the expanded state, the expansion tube 110 has a larger diameter, so that the expansion tube 110 can be adaptively positioned within the aorta 20. Thus, the blood pump 10 omits the intubation assembly 200 and directly opens the distal opening 201 at the distal end of the pump housing 100. The distal end of the pump housing 100 only needs to slightly extend into the left ventricle 40 so that the distal opening 201 of the pump housing 100 enters the left ventricle 40, and there is no need to insert through the intubation assembly 200 to the bottom of the left ventricle 40 for support and positioning.

[0156] See Figures 14 to 16 , the blood pump 10 further includes a driving unit 500. The driving unit 500 can drive the impeller 400C to rotate and work. The driving unit 500 is fixedly connected to the proximal end of the pump housing 100 and can be inserted into the blood vessel of the patient together with the pump housing 100.

[0157] See Figures 14 to 16, the drive unit 500 includes a housing 510 and a rotating shaft 520. Among them, the housing 510 is connected to the pump housing 100; the rotating shaft 520 is rotatably installed in the housing 510, and the rotating shaft 520 passes through the housing 510 and has a connection end 521 received in the pump housing 100, and the connection end 521 is fixedly connected to the impeller 400C. Specifically, the connection end 521 is fixedly connected to the hub 410 of the impeller 400C. The proximal opening 101 of the pump housing 100 is usually disposed adjacent to the distal end of the housing 510.

[0158] See Figures 14 to 16 , the drive unit 500 may further include a rotor 540 and a stator 530. The rotor 540 and the stator 530 are disposed in the housing 510, and the rotor 540 and the stator 530 are arranged at intervals along the axial direction. The rotating shaft 520 rotatably passes through the stator 530; and the rotating shaft 520 is fixedly connected to the rotor 540. The number of the stators 530 may be one or two or more; the number of the rotors 540 may also be one or two or more. When the stator 530 works, it can generate a rotating magnetic field that causes at least one rotor 540 to rotate, and the rotor 540 drives the rotating shaft 520 to rotate under the rotating magnetic field, and the impeller 400C also rotates accordingly.

[0159] Of course, the drive unit 500 may not include the rotor 540 and the stator 530. In other embodiments, the drive unit 500 may include a coupling and a flexible shaft (not shown in the figure); the coupling is received in the housing 510; the proximal end of the flexible shaft is connected to an external motor, the distal end of the flexible shaft is connected to the coupling, and the coupling is connected to the proximal end of the rotating shaft 520. Thus, the external motor drives the flexible shaft to rotate, so that the flexible shaft drives the rotating shaft 520 to rotate together through the coupling. The coupling may be a magnetic coupling or a conventional coupling. For example, the coupling is a magnetic coupling, which specifically includes a driving magnet and a driven magnet; the driving magnet is fixedly connected to the flexible shaft; the driven magnet is fixedly connected to the proximal end of the rotating shaft 520, and there is a magnetic attraction force that attracts each other between the driving magnet and the driven magnet.

[0160] See Figures 14 to 16 and Figure 18 , the proximal tube 120 of the pump housing 100 is fixedly connected to the housing 510 of the drive unit 500, and the proximal tube 120 is provided with a proximal opening 101. Optionally, the proximal tube 120 and the expansion tube 110 are of an integral structure. The proximal tube 120 may be made of the same material or different materials as the expansion tube 110. For example, both the proximal tube 120 and the expansion tube 110 are made of a shape memory metal material. However, during manufacturing, no plastic deformation treatment is performed on the proximal tube 120, so the proximal tube 120 does not have an initial shape and an expanded shape, so that the proximal tube 120 will not deform when encountering blood, ensuring that the connection between the proximal tube 120 and the drive unit 500 is firm and not easily detached.

[0161] See Figure 16 and Figure 18 At the connection between the first pipe section 112 of the expansion pipe 110 and the proximal pipe 120, a first crease T is formed 1 ; At the connection between the first pipe section 112 and the main pipe section 111, a second crease T is formed 2 See Figure 22 and Figures 24 to 26 When the expansion pipe 110 deforms from the initial shape to the expanded shape, the expansion pipe 110 bends and deforms at the first crease T 1 and the second crease T 2 , so that in the expanded shape of the expansion pipe 110, the diameter of the first pipe section 112 gradually increases from the first crease T 1 to the second crease T 2 .

[0162] See Figure 19 Optionally, the outer diameter of the expansion pipe 110 in the initial shape is denoted as the contracted outer diameter D 2a , and the contracted outer diameter D 2a is the same as the outer diameter D 6 of the proximal pipe 120. That is, D 2a = D 6 . On the one hand, this can make the internal volume of the expansion pipe 110 large enough in the initial shape to ensure that it can accommodate the impeller 400A or impeller 400C with a relatively large diameter. On the other hand, it can make the outer surface of the expansion pipe 110 and the outer surface of the proximal pipe 120 lie on the same cylindrical surface, and the outer surfaces of the two can be smoothly connected

[0163] See Figure 19 and Figure 25 Optionally, the outer diameter of the expansion pipe 110 in the expanded shape is denoted as the expanded outer diameter D 2b , and the ratio of the expanded outer diameter D 2b to the outer diameter D 6 of the proximal pipe 120 is 1.1 - 1.5. That is, 1.1 ≤ D 2b / D 6 ≤ 1.5. This ratio can specifically be, but is not limited to, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.49, etc. This can prevent the outer diameter of the expansion pipe 110 from being too large in the expanded shape

[0164] See Figures 14 to 16 and Figure 18, the distal tube 130 of the pump housing 100 is fixedly connected to the proximal end of the cannula 210. The distal tube 130 is a non-deformable structure. The distal tube 130 has a certain hardness. Optionally, the distal tube 130 and the expansion tube 110 are of an integral structure. The distal tube 130 can be made of the same material as the expansion tube 110 or a different material. For example, both the distal tube 130 and the expansion tube 110 are made of a shape memory metal material. However, during manufacturing, since no plastic deformation treatment is performed on the distal tube 130, the distal tube 130 does not have an initial shape and an expanded shape. Thus, the distal tube 130 will not deform when encountering blood, ensuring that the connection between the distal tube 130 and the cannula 210 is firm and not prone to falling off.

[0165] See Figure 18 and Figures 24 to 26 , a third crease T is formed at the connection between the second tube section 113 of the expansion tube 110 and the distal tube 130 3 ; a fourth crease T is formed at the connection between the second tube section 113 and the main tube section 111 4 . When the expansion tube 110 deforms from the initial shape to the expanded shape, the expansion tube 110 bends and deforms at the third crease T 3 and the fourth crease T 4 , so that in the expanded shape of the expansion tube 110, the diameter of the second tube section 113 gradually increases from the third crease T 3 to the fourth crease T 4 .

[0166] See Figure 19 , when the expansion tube 110 is in the initial shape, the outer diameter is denoted as the contracted outer diameter D 2a , the said contracted outer diameter D 2a is the same as the outer diameter D of the distal tube 130 7 . That is, D 2a = D 6 . On the one hand, this can make the diameter of the expansion tube 110 larger in the initial shape, so that the internal space of the expansion tube 110 is larger and can accommodate an impeller 400C with a larger diameter. On the other hand, it can make the outer surface of the expansion tube 110 and the outer surface of the proximal tube 120 located on the same cylindrical surface, and the outer surfaces of the two can be smoothly connected.

[0167] See Figure 19 and Figure 25 , optionally, when the expansion tube 110 is in the expanded shape, the outer diameter is denoted as the expanded outer diameter D 2b , the said expanded outer diameter D 2b and the outer diameter D of the distal tube 130 7 have a ratio of 1.1 to 1.5. That is, 1.1 ≤ D 2b / D 7≤1.5. This ratio can specifically be, but is not limited to, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.49, etc. This can avoid the outer diameter of the expansion tube 110 being too large in the expanded state.

[0168] It can be understood that the proximal tube 120 is not necessary. The proximal opening 101 can be provided at the proximal end of the expansion tube 110, that is, the proximal opening 101 is provided on the first tube section 111; the proximal end of the first tube section 111 is fixedly connected to the housing 510 of the drive unit 500. The distal tube 130 is also not necessary and can be connected from the distal end of the expansion tube 110 to the cannula 210.

[0169] See Figures 14 to 16 , the blood pump 10 further includes a catheter 300, and the catheter 300 is connected to the proximal end of the drive unit 500. The catheter 300 has a lumen, and the lumen of the catheter 300 can accommodate cables such as a flushing pipeline, a sensor optical fiber, and a wire of the stator 530.

[0170] See Figure 14 and Figure 15 , the blood pump 10 further includes a pressure sensor 600 for detecting blood pressure. In some traditional technologies, the pressure sensor 600 is fixed to the pump housing 100 with adhesive. Here, it is considered that if the pressure sensor 600 is still installed on the pump housing 100 in this embodiment, when the expansion tube 110 of the pump housing 100 expands and deforms, it may pull the pressure sensor 600, and there is a risk of the adhesive of the pressure sensor 600 falling off.

[0171] Therefore, in this embodiment, the pressure sensor 600 is installed on the drive unit 500, so that when the expansion tube 110 of the pump housing 100 expands and deforms, the pressure sensor 600 will not be pulled, and thus the pressure sensor 600 is not easily detached and the installation is more stable.

[0172] Specifically, the pressure sensor 600 includes a probe and an optical fiber connected to the probe; the optical fiber is accommodated inside the catheter 300. The probe is installed inside the housing 510 of the drive unit 500. The side wall of the housing 510 is provided with a detection window; the probe corresponds to the detection window to be able to sense blood pressure.

[0173] See Figure 29 , the present application also provides a manufacturing method for manufacturing the pump housing 100 of the blood pump 10:

[0174] The first step is to take a cylindrical tube M made of a shape memory material as shown in (a) of Figure 29 .

[0175] The second step is as shown in Figure 29As shown in (b) therein, on the cylindrical tube M, the proximolateral tube 120, the distolateral tube 130 arranged axially and the expansion tube 110 located between the proximolateral tube 120 and the distolateral tube 130 are divided as expected.

[0176] Specifically, the expansion tube 110 is further divided into a first part P arranged axially 1 , a second part P 2 and a third part P located between the first part P 1 and the second part P 2 . The first part P 3 is connected to the proximolateral tube 120, and the second part P 1 is connected to the distolateral tube 130. 2

[0177] The third step is that, as shown in (c) therein, the expansion tube 110 of the cylindrical tube M is radially expanded, while the proximolateral tube 120 and the distolateral tube 130 remain unchanged without expansion, so that only the expansion tube 110 obtains an expanded shape. Figure 29

[0178] Specifically, the third part P of the expansion tube 110 3 is radially expanded to form a main pipe section 111; in this process, the diameter of the first part P 1 gradually becomes larger from the distal end of the proximolateral tube 120 towards the direction close to the main pipe section 111, so that the first part P 1 forms a first pipe section 112; the diameter of the second part P 2 gradually becomes larger from the proximal end of the distolateral tube 130 towards the direction close to the main pipe section 111, so that the second part P 2 forms a second pipe section 113 of the expansion tube 110. A first crease T 1 and a second crease T 2 are respectively formed at both ends of the first pipe section 112; a third crease T 3 and a fourth crease T 4 are respectively formed at both ends of the second pipe section 113.

[0179] The fourth step is that, as shown in (d) therein, the pump housing 100 is heat-treated, and the expansion tube 110 of the pump housing 100 is compressed to its initial shape after heat treatment. Since the proximolateral tube 120 and the distolateral tube 130 are not expanded in the third step, the proximolateral tube 120 and the distolateral tube 130 will not be deformed during heat treatment in this fourth step. The expansion tube 110 shrinks to be approximately the same size as the proximolateral tube 120 and the distolateral tube 130, so that the expansion tube 110 of the pump housing 100 obtains its initial shape. In this shape, the proximolateral tube 120, the distolateral tube 130 and the expansion tube 110 are approximately a cylindrical tube. Figure 29

[0180] After the pump housing 100 is processed in the above-mentioned fourth step, the expansion tube 110 can be stably maintained in its initial shape without heating. After the pump housing 100 is pushed into the body with the blood pump 10 in this shape, under the influence of the blood temperature, the expansion tube 110 of the pump housing 100 gradually expands and returns to the expanded shape.

[0181] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0182] The above-described embodiments only represent several implementation manners of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A blood pump, characterized in that: The blood pump comprises: a pump housing having a proximal opening; and An impeller is rotatably disposed in the pump housing; wherein, The pump housing includes an expansion tube for accommodating the impeller, the expansion tube includes a first shape memory material, and the expansion tube has an initial shape and an expanded shape that expands relative to its initial shape; the first shape memory material can be deformed under blood temperature conditions to cause the expansion tube to expand from the initial shape to the expanded shape.

2. The blood pump according to claim 1, characterized in that The expansion tube also has at least one of the following characteristics: The first shape memory material is a shape memory metal; The temperature at which the first shape memory material deforms is 34° C. to 39° C.; The expansion tube is in a circular tube shape in the initial state; The initial shape of the expansion tube does not require external force to maintain; The expansion tube can be received in the aorta in the expanded state; The maximum outer diameter of the expansion tube in the expanded state allows the expansion tube to pass through the narrowest position on the pushing path in the body.

3. The blood pump according to claim 1, characterized in that The impeller includes a second shape memory material, and the impeller also has an initial shape and an expanded shape relative to its initial shape; the second shape memory material can be deformed under blood temperature conditions to enable the impeller to expand from the initial shape to the expanded shape.

4. The blood pump according to claim 3, characterized in that The impeller also has at least one of the following features: The second shape memory material is a shape memory metal; The temperature at which the second shape memory material deforms is 34° C. to 39° C.; The initial shape of the impeller does not require external force to maintain.

5. The blood pump according to claim 3, characterized in that The inner diameter of the expansion tube in the initial state is the contraction inner diameter D 1a The diameter of the impeller in its initial state is the initial diameter D 5a The diameter of the impeller in the expanded state is the working diameter D 5b , where D 5b >D 5a , and D 5b ≥D 1a .

6. The blood pump according to claim 3, characterized in that: The diameter of the impeller in the expanded state is the working diameter D 5b The pump housing also includes a proximal tube, which is connected to the proximal end of the expansion tube and is provided with the proximal opening. The proximal tube is a non-deformable structure, and the working diameter D 5b is larger than the inner diameter of the proximal tube; and / or, The pump housing further comprises a distal tube, which is connected to the distal end of the expansion tube. The distal tube is a non-deformable structure. The working diameter D 5b Larger than the inner diameter of the distal tube.

7. The blood pump according to claim 1, characterized in that The impeller is a non-expandable rigid impeller; when the expansion tube is in an initial state, the width of the radial gap between the inner wall surface of the expansion tube and the impeller is 0 mm to 0.06 mm or 0.08 mm to 2 mm.

8. The blood pump according to claim 1, characterized in that When the expansion tube is in an expanded state, the width of the radial gap between the inner wall surface of the expansion tube and the impeller is 0.1 mm to 0.3 mm.

9. The blood pump according to any one of claims 1 to 8, characterized in that: The expansion tube is provided with a deformation hole, which extends along the axial direction of the pump housing. A flexible membrane covering the deformation hole is provided in the deformation hole. When the expansion tube recovers from an initial shape to an expanded shape, the flexible membrane can be stretched or unfolded along the circumference of the pump housing.

10. The blood pump according to claim 9, characterized in that The expansion tube is provided with a plurality of deformation holes, which are arranged at intervals along the circumference of the expansion tube; a deformation flap extending along the axial direction of the pump housing is formed between two adjacent deformation holes.

11. The blood pump according to claim 10, characterized in that The deformation hole has a first width W1 extending along the circumference of the pump housing, the deformation petal has a second width W2 extending along the circumference of the pump housing, and the outer diameter of the expansion tube in the initial state is the contraction outer diameter D 2a ; Wherein, W2>W1; and / or, W2≥0.25πD 2a .

12. The blood pump according to claim 10, characterized in that The expansion tube also has at least one of the following characteristics: The number of the deformation petals of the expansion tube is 2 to 5; The periphery of the flexible membrane of the expansion tube is fixedly connected to the periphery of the deformation hole; The expansion tube is in an initial state, and the flexible membrane is folded in the deformation hole.

13. The blood pump according to claim 9, characterized in that The impeller includes a hub and blades arranged on the hub, and the blades are located in the expansion tube; wherein, The deformation hole has a first length extending along the axial direction of the pump housing, and the blade has a second length extending along the axial direction of the pump housing, the first length is greater than the second length, and both ends of the deformation hole extend beyond both ends of the blade; And / or, the blade is completely accommodated in the expansion tube, and the proximal end of the blade is spaced apart from the proximal end of the expansion tube by a first distance along the axial direction of the pump casing, and the distal end of the blade is spaced apart from the distal end of the expansion tube by a second distance along the axial direction of the pump casing.

14. The blood pump according to any one of claims 1 to 8, characterized in that: The expansion pipe includes a first pipe section, a second pipe section and a main pipe section connected between the first pipe section and the second pipe section; when the expansion pipe is in an expanded state, the diameter of the first pipe section gradually decreases from the distal end to the proximal end of the pump casing; the diameter of the second pipe section gradually decreases from the proximal end to the distal end of the pump casing.

15. The blood pump according to claim 1, characterized in that The blood pump further includes a driving unit, the driving unit including a housing and a rotating shaft connected to the impeller; the pump housing further includes a proximal tube connected to the proximal end of the expansion tube, the proximal tube is fixedly connected to the housing, and the proximal tube is provided with the proximal opening; wherein the pump housing also has at least one of the following features: The proximal tube is a non-deformable structure; The proximal tube and the expansion tube are an integrated structure; The outer diameter of the expansion tube in the initial state is the contraction outer diameter D 2a , the contraction outer diameter D 2a having the same outer diameter as the proximal tube; The outer diameter of the expansion tube in the expanded state is the expanded outer diameter D 2b , the expanded outer diameter D 2b The ratio of the outer diameter of the proximal tube to the outer diameter of the proximal tube is 1.1 to 1.

5.

16. The blood pump according to any one of claims 1 to 8, characterized in that The pump housing assembly further includes a cannula assembly having a blood flow channel; the pump housing further includes a distal tube connected to the distal end of the expansion tube, the distal tube being fixedly connected to the proximal end of the cannula assembly; wherein the pump housing further has at least one of the following features: The distal tube is a non-deformable structure; The distal tube and the expansion tube are an integrated structure; The outer diameter of the expansion tube in the initial state is the contraction outer diameter D 2a , the contraction outer diameter D 2a The same as the outer diameter D7 of the distal tube; The outer diameter of the expansion tube in the expanded state is the expanded outer diameter D 2b , the expanded outer diameter D 2b The ratio of the outer diameter D7 of the distal tube is 1.1 to 1.5.

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