CN120053873A

CN120053873A - Blood pump

Info

Publication number: CN120053873A
Application number: CN202510327391.6A
Authority: CN
Inventors: 肖振中; 杨羽卓; 余顺周
Original assignee: Shenzhen Core Medical Technology Co Ltd
Current assignee: Shenzhen Core Medical Technology Co Ltd
Priority date: 2025-03-19
Filing date: 2025-03-19
Publication date: 2025-05-30

Abstract

The present application relates to a blood pump. The blood pump comprises a pump shell and an impeller, wherein the pump shell is provided with a proximal opening, and the impeller is rotatably arranged in the pump shell. The pump shell comprises a dilatation tube for accommodating the impeller, the dilatation tube comprises a first shape memory material, so that the dilatation tube has an initial shape and an expanded shape corresponding to the initial shape, and the first shape memory material can deform under the condition of blood temperature to expand the dilatation tube from the initial shape to the expanded shape. The blood pump can reduce hemolysis and improve the safety performance of the blood pump.

Description

Blood pump

Technical Field

The application relates to the technical field of medical equipment, in particular to a blood pump.

Background

Blood pumps are often used to push blood from a blood vessel to a patient's heart to assist the patient's heart in pumping blood from the heart chamber into an artery, enabling support for the patient's blood circulation. The blood pump is provided with an impeller, and the impeller is driven to rotate so as to drive blood to flow. When the blood pump works, the problem of hemolysis is easy to occur in the process that blood flows through the impeller, so that the blood pump has potential safety hazards.

Disclosure of Invention

Based on this, it is necessary to provide a blood pump which aims to reduce hemolysis and improve the safety performance of the blood pump.

In one embodiment of the blood pump provided by the application, the blood pump comprises a pump shell and an impeller, wherein the pump shell is provided with a proximal opening, and the impeller is rotatably arranged in the pump shell. The pump shell comprises a dilatation tube for accommodating the impeller, the dilatation tube comprises a first shape memory material, so that the dilatation tube has an initial shape and an expanded shape corresponding to the initial shape, and the first shape memory material can deform under the condition of blood temperature to expand the dilatation tube from the initial shape to the expanded shape.

In some embodiments, the flash tube further has at least one of the following features:

The first shape memory material is a shape memory metal;

the temperature at which the first shape memory material deforms is 34-39 ℃;

the shape of the dilatation tube in the initial form is a circular tube;

The expansion tube is maintained in an initial form without external force;

The dilatation tube can be accommodated in the aorta in an expanded configuration;

The maximum outer diameter of the dilatation tube in the expanded configuration allows the dilatation tube to pass through the narrowest location on the push path in the body.

In some embodiments, the impeller includes a second shape memory material to provide the impeller with an initial configuration and an expanded configuration that expands relative to the initial configuration, the second shape memory material being capable of deforming under blood temperature conditions to expand the impeller from the initial configuration to the expanded configuration.

In some embodiments, the impeller further 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 34-39 ℃;

The impeller is maintained in an initial configuration without external forces.

In some embodiments, the inner diameter of the dilatation tube in the initial configuration is a contracted inner diameter D _1a, the diameter of the impeller in the initial configuration is an initial diameter D _5a, and the diameter of the impeller in the expanded configuration is a working diameter D _5b, wherein D _5b＞D_5a and D _5b≥D_1a.

In some embodiments, the impeller has a diameter in the expanded configuration of an operating diameter D _5b, the pump housing further comprises a proximal tube connected to the proximal end of the flash tube and provided with the proximal opening, the proximal tube is of non-deformable configuration, the operating diameter D _5b is greater than the inner diameter of the proximal tube, and/or,

The pump housing further includes a distal tube connected to the distal end of the flash tube, the distal tube being of non-deformable configuration, the working diameter D _5b being greater than the inner diameter of the distal tube.

In some embodiments, the impeller is a non-expandable rigid impeller, and the radial gap between the inner wall surface of the expansion tube and the impeller is 0 mm-0.06 mm or 0.08 mm-2 mm when the expansion tube is in an initial state.

In some embodiments, when the dilatation tube is in the expanded state, a radial gap between the inner wall surface of the dilatation tube and the impeller has a width of 0.1 mm-0.3 mm.

In some embodiments, the dilatation tube is provided with a deformation hole, the deformation hole extends along the axial direction of the pump shell, a flexible membrane covering the deformation hole is arranged in the deformation hole, and the dilatation tube can stretch or unfold the flexible membrane along the circumferential direction of the pump shell when returning from an initial state to an expanded state.

In some embodiments, the expansion pipe is provided with a plurality of deformation holes, the deformation holes are arranged at intervals along the circumferential direction of the expansion pipe, and deformation petals extending along the axial direction of the pump shell are formed between two adjacent deformation holes.

In some embodiments, the deformation orifice has a first width extending circumferentially of the pump casing, the deformation flap has a second width extending circumferentially of the pump casing, the second width being greater than the first width in the initial configuration, and/or the expansion tube has a contracted outer diameter D _2a and a W+.gtoreq.0.25 pi D _2a in the initial configuration.

The number of the deformation lobes is 2-5;

The periphery of the flexible film is fixedly connected with the periphery of the deformation hole;

the dilatation tube is in an initial state, and the flexible membrane is folded in the deformation hole.

In some embodiments, the impeller comprises a hub and blades disposed on the hub, the blades being disposed within the expansion tube, wherein,

The deformation hole has a first length extending in an axial direction of the pump case, the blade has a second length extending in the axial direction of the pump case, 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 blades are fully accommodated in the dilatation tube, a first interval is formed between the proximal ends of the blades and the proximal ends of the dilatation tube along the axial direction of the pump shell, and a second interval is formed between the distal ends of the blades and the distal ends of the dilatation tube along the axial direction of the pump shell.

In some embodiments, the expansion tube comprises a first tube section, a second tube section and a main tube section connected between the first tube section and the second tube section, wherein in an expanded configuration, the diameter of the first tube section gradually decreases along the direction from the distal end to the proximal end of the pump shell, and the diameter of the second tube section gradually decreases along the direction from the proximal end to the distal end of the pump shell.

In some embodiments, the blood pump further comprises a driving unit, the driving unit comprises a shell and a rotating shaft connected with the impeller, the pump shell further comprises a proximal tube connected to the proximal end of the dilatation tube, the proximal tube is fixedly connected with the shell, and the proximal tube is provided with the proximal opening.

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

The proximal tube is a non-deformable structure;

the proximal tube and the dilatation tube are of an integrated structure;

The outer diameter of the dilatation tube in the initial state is a contracted outer diameter D _2a, and the contracted outer diameter D _2a is the same as the outer diameter of the proximal tube;

the outer diameter of the dilatation tube in the expanded state is an expanded outer diameter D _2b, and the ratio of the expanded outer diameter D _2b to the outer diameter of the proximal tube is 1.1-1.5.

In some embodiments, the pump housing assembly further comprises a cannula assembly having a blood flow path, and the pump housing further comprises a distal tube coupled to the distal end of the flash tube, the distal tube being fixedly coupled to the proximal end of the cannula assembly.

The distal tube is a non-deformable structure;

The far side pipe and the dilatation pipe are of an integrated structure;

The outer diameter of the dilatation tube in the initial state is a contracted outer diameter D _2a, and the contracted outer diameter D _2a is the same as the outer diameter D ₇ of the distal tube;

The outer diameter of the dilatation tube in the expanded state is an expanded outer diameter D _2b, and the ratio of the expanded outer diameter D _2b to the outer diameter D ₇ of the distal tube is 1.1-1.5.

According to the blood pump, the dilatation tube of the pump shell comprises the first shape memory material, so that the dilatation tube has an initial shape and an expanded shape which is expanded relative to the initial shape, and the first shape memory material can deform under the condition of blood temperature, so that the dilatation tube is expanded from the initial shape to the expanded shape, and the inner diameter of the dilatation tube can be increased. Thus, the blood pump can properly reduce the initial width of the radial gap between the inner wall surface of the expansion tube and the impeller in the initial state, even without reserving the radial gap, so that the blood pump can replace the impeller with a large diameter instead of the conventional impeller with a small diameter. The impeller with large diameter has higher hydraulic performance, so that the blood pump can properly reduce the rotating speed of the impeller so as to reduce the collision degree of the impeller blades and blood cells, further reduce the damage of the blood cells and effectively reduce hemolysis.

Of course, the blood pump may also employ the conventional impeller having a small diameter as usual, and after the expansion tube is expanded from the initial state to the expanded state, the width of the radial gap between the impeller and the inner wall surface of the expansion tube becomes larger, so that blood cells can smoothly pass through the radial gap, and thus damage of the impeller to the blood cells passing through the radial gap can be greatly reduced, and hemolysis can be reduced.

Drawings

Fig. 1 is a block diagram showing a pump casing of a blood pump according to a first embodiment of the present application in an initial state.

Fig. 2 is an exploded schematic view of the blood pump provided in fig. 1.

Fig. 3 is a schematic longitudinal section of the blood pump provided in fig. 1.

Fig. 4 is a schematic cross-sectional view of the blood pump provided in fig. 1.

Fig. 5 is an isometric view of a pump housing of the blood pump provided in fig. 1.

Fig. 6 is a structural view of a pump casing of the blood pump according to the first embodiment of the present application in an expanded configuration.

Fig. 7 is an exploded schematic view of the blood pump provided in fig. 6.

Fig. 8 is a schematic longitudinal section of the blood pump provided in fig. 6.

Fig. 9 is a schematic cross-sectional view of the blood pump provided in fig. 6.

Fig. 10 is an isometric view of a pump housing of the blood pump provided in fig. 6.

Fig. 11 is a schematic view showing a large-diameter rigid impeller accommodated in a dilatation tube of a blood pump according to a first embodiment of the present application in an initial state and an expanded state, respectively.

Fig. 12 is a schematic view of a blood pump according to a second embodiment of the present application, in which a small diameter rigid impeller is accommodated in an initial configuration and an expanded configuration, respectively.

Fig. 13 is a schematic view of a blood pump according to a third embodiment of the present application, in which the expandable impeller is housed in an initial configuration and in an expanded configuration, respectively.

Fig. 14 is a structural view of a pump casing of a blood pump according to a third embodiment of the present application in an initial state.

Fig. 15 is an exploded view of the blood pump provided in fig. 14.

Fig. 16 is a schematic longitudinal section of the blood pump provided in fig. 14.

Fig. 17 is a schematic cross-sectional view of the blood pump provided in fig. 14.

Fig. 18 is an isometric view of a pump housing of the blood pump provided in fig. 14.

Fig. 19 is a front view of the pump housing provided in fig. 18.

Fig. 20 is a structural view of a pump casing of a blood pump according to a third embodiment of the present application in an expanded configuration.

Fig. 21 is an exploded view of the blood pump provided in fig. 20.

Fig. 22 is a schematic longitudinal section of the blood pump provided in fig. 20.

Fig. 23 is a schematic cross-sectional view of the blood pump provided in fig. 20.

Fig. 24 is an isometric view of a pump housing of the blood pump provided in fig. 20.

Fig. 25 is a front view of the pump housing provided in fig. 24.

Fig. 26 is a front view of the pump housing provided in fig. 25, taken along line I-I.

Fig. 27 is a schematic view of the initial push of the blood pump of the present application into the body.

Fig. 28 is a schematic view of a blood pump of the present application being pushed to a target site in a body.

Fig. 29 is a flow chart of the manufacturing process of the pump housing for manufacturing the blood pump according to the present application.

Detailed Description

In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the application, whereby the application is not limited to the specific embodiments disclosed below.

In the description of the present application, it should be understood that, if any, these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., are used herein with respect to the orientation or positional relationship shown in the drawings, these terms refer to the orientation or positional relationship for convenience of description and simplicity of description only, and do not indicate or imply that the apparatus or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the application.

Furthermore, the terms "first," "second," and the like, if any, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the terms "plurality" and "a plurality" if any, mean at least two, such as two, three, etc., unless specifically defined otherwise.

In the present application, unless explicitly stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly. For example, they may be fixedly connected, detachably connected or integrally formed, mechanically connected, electrically connected, directly connected or indirectly connected through an intermediate medium, and communicated between two elements or the interaction relationship between two elements unless clearly defined otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present application, unless expressly stated or limited otherwise, the meaning of a first feature being "on" or "off" a second feature, and the like, is that the first and second features are either in direct contact or in indirect contact through an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that if an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. If an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein, if any, are for descriptive purposes only and do not represent a unique embodiment.

It should be noted that "distal" and "proximal" are used throughout to refer to a relative positional relationship, where "distal" of a component refers to an end of the component that is first introduced into a patient and/or is farther from an operator than the other end during normal operation, and "proximal" refers to an end that is later introduced into the patient and/or is closer to the operator than the other end.

In the related art, an impeller is provided in a pump casing of a blood pump, and the impeller is driven to rotate so as to drive blood to flow. When the blood pump works, the problem of hemolysis is easy to occur in the process that blood flows through the impeller, so that the blood pump has potential safety hazards.

For this reason, the present application has studied the problem and analyzed the cause of its generation. According to research, a radial gap is reserved between the inner wall surface of the pump shell and the impeller, and the impeller can freely rotate through the radial gap, so that the impeller is prevented from contacting the inner wall surface of the pump shell when rotating. On the one hand, if the diameter of the impeller is designed to be larger, the radial clearance reserved by the impeller is smaller, so that blood cells cannot smoothly flow through the radial clearance, and the blood cells are more likely to collide with the blades of the impeller to be damaged, thereby causing hemolysis. On the other hand, if the radial clearance is designed to be large, the diameter of the impeller is reduced, and the hydraulic performance of the small-diameter impeller is poor (i.e., the flow rate is small), in which case, if the requirement of the blood pump on the hydraulic performance is to be satisfied, the rotation speed of the impeller must be increased, but the degree of collision of the impeller on blood cells is increased, and thus hemolysis is increased.

In view of the above, the present application provides a blood pump 10, which is capable of reducing the hemolysis rate of the blood pump 10 and improving the safety performance of the blood pump 10, see fig. 1, 27 and 28. The blood pump 10 is primarily adapted for pushing through the aorta 20 to the left ventricle 40 to assist the left heart in pumping blood. Of course, in other embodiments, it may also be applied to push through the right ventricle to the pulmonary artery to assist the right heart in pumping blood. Various embodiments of the blood pump of the present application are described in detail below.

Fig. 1 to 11 show a first embodiment of the blood pump of the present application. Referring to fig. 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 and an impeller 400A is rotatably disposed within the pump housing 100.

Referring to fig. 3, 27 and 28, when the blood pump 10 is advanced to the left ventricle 40 via the aorta 20, the distal end of the blood pump 10 is positioned within the left ventricle 40 and the proximal opening 101 of the blood pump 10 is positioned within the aorta 20. Upon rotation of the drive impeller 400A, blood from the left ventricle 40 flows into the interior of the pump housing 100 from the distal end of the blood pump 10 and out of the proximal opening 101 to the aorta 20 to assist in blood pumping.

Referring to fig. 1 to 3, the impeller 400A includes a hub 410 and blades 420 disposed on the hub 410. The number of blades 420 may be 2, 3 or 4. During the rotation operation of the impeller 400A, the blades 420 of the impeller 400A and the inner wall surface 103 of the pump casing 100 need to be kept with a certain radial gap 102, and the radial gap 102 allows the impeller 400A to rotate in the pump casing 100 without coming into contact with the inner wall surface 103 of the pump casing 100.

In this embodiment, impeller 400A is a non-deployable rigid impeller. That is, the impeller 400A has a constant shape, and the shape of the impeller 400A is not deformed before and after the blood pump 10 enters the patient. Of course, in other embodiments (such as the third embodiment described below), the impeller 400A may be replaced with a deployable impeller 400A.

Referring to fig. 1 and 2, and fig. 6 and 7, the pump casing 100 includes a capacity-expanding tube 110, and an impeller 400A is accommodated inside the capacity-expanding tube 110. The flash tube 110 includes a first shape memory material such that the flash tube 110 has an initial configuration and an expanded configuration that expands relative to its initial configuration. Wherein fig. 1 and 2 show the dilatation tube 110 in an initial configuration and fig. 6 and 7 show the dilatation tube 110 in an expanded configuration.

The first shape memory material is capable of deforming under temperature conditions at blood temperature conditions to expand the flash tube 110 to an expanded configuration in an initial configuration. After the dilatation tube 110 expands from the initial configuration to the original expanded configuration at the blood temperature, the inner diameter of the dilatation tube 110 can be increased.

It will be appreciated that the first shape memory material is capable of automatically returning to its pre-heat-treated form upon stimulation at a desired temperature (such as blood temperature) after plastic deformation by heat treatment. Thus, for the dilatation tube 110 comprising the first shape memory material, the dilatation tube 110 is in its expanded configuration prior to heat treatment and is in its pre-formed working configuration, and the dilatation tube 110 in its expanded configuration is plastically deformed upon heat treatment, the diameter of the dilatation tube 110 being contracted such that the dilatation tube 110 is deformed from its expanded configuration to its initial configuration. The initial configuration is the configuration that the dilatation tube 110 assumes during the period from after heat treatment to before entering the patient. When the initial configuration of the flash tube 110 is heated to a desired temperature (such as blood temperature), the flash tube 110 automatically reverts from the initial configuration to the expanded configuration (i.e., the working configuration).

Wherein the blood temperature refers to the blood temperature of a normal human body, such as 36 ℃ to 37.5 ℃. However, to ensure that the flash tube 110 can also expand normally in some patients with low or high blood temperatures, the temperature at which the first shape memory material deforms is 34-39 ℃, so that the flash tube 110 can be configured to expand from an initial configuration to an expanded configuration over a temperature range of 34-39 ℃.

Additionally, the first shape memory material may be a shape memory polymer or a shape memory alloy. The shape memory polymer can realize transition temperature control by adjusting molecular structure. The shape memory polymer may be PLC, PU, PLA, or the like. The shape memory alloy can realize transition temperature control by adjusting alloy components. The shape memory alloy may be a nickel-containing alloy, a titanium-containing alloy, or the like. It should be noted that the first shape memory material should be selected to be harmless to the human body and applicable to the human body. In particular, in this embodiment, the flash tube 110 is made of a shape memory alloy, such as nickel-titanium alloy.

Referring to fig. 4 and 9, after the expansion tube 110 is expanded from the initial configuration to the expanded configuration, the inner diameter of the expansion tube 110 increases, i.e., the inner diameter of the expansion tube 110 in the expanded configuration is greater than the inner diameter of the expansion tube 110 in the initial configuration. The inner diameter of the expansion tube 110 in the initial state is referred to as the contracted inner diameter D _1a, and the inner diameter of the expansion tube 110 in the expanded state is referred to as the expanded inner diameter D _1b, D _1b＞D_1a.

In manufacturing the blood pump 10, the dilatation tube 110 of the pump housing 100 may be prefabricated into a desired expanded configuration, then the pump housing 100 is heat treated to plastically deform and contract the dilatation tube 110 into an initial configuration, and finally the dilatation tube 110 is assembled to the blood pump 10 in the initial configuration. In other embodiments, the flash tube 110 may be assembled to the blood pump 10 in an expanded configuration, and then the flash tube 110 may be heat treated to plastically deform and contract the flash tube 110 into an initial configuration.

Referring to fig. 11, the width of the radial gap 102 between the inner wall surface 103 of the expansion tube 110 and the impeller 400A in the initial state of the expansion tube 110 is referred to as an initial width K ₁, and the width of the radial gap 102 between the inner wall surface 103 of the expansion tube 110 and the impeller 400A in the expanded state of the expansion tube 110 is referred to as a final width K ₂. When the dilatation tube 110 expands from the initial configuration to the expanded configuration, the inner diameter of the dilatation tube 110 increases, while the diameter of the impeller 400A remains the same, and the width of the radial gap 102 increases, K ₂＞K₁. Thus, the initial width K ₁ of the radial gap 102 to be reserved for the blood pump 10 may be smaller, or even equal to 0mm, so that the blood pump may use an impeller 400A having a large diameter D ₃ instead of the conventional impeller 400B having a small diameter D ₄ (see fig. 12). The impeller 400A with the large diameter D ₃ has higher hydraulic performance, so that the rotational speed of the impeller 400A can be properly reduced by the blood pump 10, so as to reduce the collision degree between the blades 420 of the impeller 400A and blood cells, further reduce the damage to the blood cells, and effectively reduce hemolysis.

Referring to fig. 27, when the blood pump 10 is pushed into the body through the wound, the dilatation tube 110 is introduced into the patient in its initial configuration. Referring to fig. 28, when the blood pump 10 is advanced to the left ventricle 40 via the aorta 20, the distal end of the blood pump 10 is advanced into the left ventricle 40, and both the dilatation tube 120 and the proximal opening 101 are housed in the aorta 20. After the dilatation tube 110 contacts with blood in the body, the heat of the blood gradually heats the dilatation tube 110, and the dilatation tube 110 gradually expands after reaching the blood temperature, so that the dilatation tube 110 automatically returns to the expanded form from the initial form, the inner diameter of the dilatation tube 110 is increased, and the width of the radial gap 102 is increased from the initial width K ₁ to the final width K ₂. It is understood that initial width K ₁ is greater than or equal to 0mm and final width K ₂ is greater than initial width K ₁. As for the size of the final width K ₂, it is sufficient that the final width K ₂ allows the impeller 400A to be rotated without being easily contacted with the inner wall surface of the dilatant 110.

It can be seen that in the blood pump 10 of the present application, the dilatation tube 110 of the pump housing 100 includes the first shape memory material, so that the dilatation tube 110 has an initial shape and an expanded shape corresponding to the initial shape, and the first shape memory material is capable of being deformed under the condition of blood temperature, so that the dilatation tube 110 is expanded from the initial shape to the expanded shape, thereby increasing the inner diameter of the dilatation tube 110. Thus, the initial width K ₁ of the radial gap 102 to be reserved for the blood pump 10 may be smaller, or even equal to 0mm, so that the blood pump 10 may use the impeller 400A having the large diameter D ₃ instead of the conventional impeller 400B having the small diameter D ₄. The impeller 400A with the large diameter D ₃ has higher hydraulic performance, so that the rotational speed of the impeller 400A can be properly reduced by the blood pump 10, so as to reduce the collision degree between the blades 420 of the impeller 400A and blood cells, further reduce the damage to the blood cells, and effectively reduce hemolysis.

As shown in fig. 11 (a), in the initial configuration of the dilatation tube 110, the width of the radial gap 102 between the inner wall surface 103 of the dilatation tube 110 and the impeller 400A (i.e. the initial width K ₁) may be set to K ₁ <0.08mm. At this time, the impeller 400A is not yet operated, so K ₁ is small but does not affect the impeller 400A.

Optionally, the initial width K ₁ is set to 0.ltoreq.K ₁.ltoreq.0.06 mm. The initial width K ₁ may be, but is not limited to, 0mm, 0.01mm, 0.02mm, 0.03mm, 0.05mm, 0.06mm, etc. When K ₁ =0 mm, the diameter D ₃ of the impeller 400A is maximum, and the diameter D ₃ of the impeller 400A is equal to the inner diameter of the flash tube 110 in the initial form (i.e., the contracted inner diameter D _1a), i.e., D ₃＝D_1a. Therefore, for a rigid impeller 400A, the maximum value of the diameter D ₃ of the impeller 400A can be the same as the inner diameter of the flash tube 110 in the initial configuration (i.e., the contracted inner diameter D _1a).

As shown in fig. 11 (a) and (b), after the dilatation tube 110 expands from the initial configuration to the expanded configuration, the width of the radial gap 102 increases from an initial width K ₁ to a final width K ₂, obviously K ₂＞K₁. The final width K ₂ can satisfy the safe and stable rotation of the impeller 400A. If the final width K ₂ is set to be 0.08-0.3 mm, namely K ₂ is more than or equal to 0.08mm and less than or equal to 0.3mm. Still alternatively, 0.1 mm.ltoreq.K ₂.ltoreq.0.3 mm. The final width K ₂ may take the values of, but is not limited to, 0.09mm, 0.1mm, 0.12mm, 0.15mm, 0.18mm, 0.2mm, 0.25mm, 0.28mm, 0.3mm, etc.

Since the dilatation tube 110 comprises the first shape memory material, the first shape memory material is capable of deforming under temperature conditions at blood temperature conditions such that the dilatation tube 110 expands in an initial configuration to an expanded configuration. That is, the first shape memory material is deformed by temperature stimulation. Thus, the first shape memory material does not deform when the first shape memory material is not subjected to a corresponding temperature stimulus. Accordingly, when the initial shape of the dilatation tube 110 is not thermally stimulated (i.e., blood temperature stimulation), the dilatation tube 110 can maintain the contracted shape relative to the expanded shape without external force, i.e., the initial shape of the dilatation tube is maintained without external force. The shape of the dilatation tube 110 in the initial configuration allows the dilatation tube 110 to enter the body more smoothly. Thus, the dilatation tube 110 can be maintained in a contracted configuration relative to the expanded configuration without the need for external force compression by the sheath. After the subsequent dilatation tube 110 is stimulated by the blood temperature, the dilatation tube 110 gradually expands, and the dilatation tube 110 is capable of expanding to an expanded configuration when reaching a target location (such as an end of the aorta 20 adjacent the aortic valve 30) within a desired time.

It should be noted that, under normal conditions, when the dilatation tube 110 has not reached the target position before the expected time, the dilatation tube 110 is in the initial configuration or in the incompletely expanded configuration, the outer diameter of the dilatation tube 110 is kept small, so that the dilatation tube 110 is pushed in the body, and the dilatation tube 110 is not completely expanded to the expanded configuration until the dilatation tube 110 reaches the target position at the expected time, so that the width of the radial gap 102 is increased from the initial width K ₁ to the final width K ₂.

However, in some unexpected situations, such as insufficient experience of the physician handling the blood pump 10 or high resistance to the delivery path in the patient, which may result in an extended time for the blood pump 10 to be delivered into the patient, the dilatation tube 110 may be inflated to the expanded configuration in advance without reaching the target site, and the larger outer diameter of the dilatation tube 110 may affect the subsequent advancement of the dilatation tube 110 toward the target site.

To reduce this occurrence, the maximum outer diameter of the dilatation tube 110 in the expanded configuration may be set to allow the dilatation tube 110 to pass through the narrowest location on the body's push path. Thus, if the time for which the blood pump 10 is pushed into the body is prolonged due to an unexpected situation, the dilatation tube 110 can smoothly pass through the narrowest position on the body pushing path in the expanded configuration because the maximum outer diameter of the dilatation tube 110 in the expanded configuration allows the dilatation tube 110 to pass through the narrowest position on the body pushing path if the dilatation tube 110 is fully expanded to the expanded configuration before reaching the aorta 20. In addition, when the blood pump 10 is withdrawn from the patient, the dilatation tube 110 can smoothly pass through the narrowest position on the in-vivo pushing path in the expanded form, so that the pushing auxiliary sheath into the body is not required to cover and squeeze the dilatation tube 110 to reduce the outer diameter thereof.

It will be appreciated that the narrowest location on the body delivery path varies from patient to patient. Such as elderly and children, obese patients, or lean patients. Therefore, the maximum outer diameter of the dilatation tube 110 in the expanded configuration should be reasonably designed according to the narrowest position on the body-pushing path of the patient for practical use, and is not specifically described herein.

Of course, in other embodiments, to avoid the dilatation tube 110 expanding to the expanded configuration in advance when the dilatation tube 110 does not reach the target position, the dilatation tube 110 may be wrapped with an auxiliary sheath, the auxiliary sheath and the dilatation tube 110 may be pushed together to the target position, and then the auxiliary sheath may be withdrawn from the body. After the auxiliary sheath is separated from the dilatation tube 110, the dilatation tube 110 expands to an expanded configuration.

It is further worth mentioning that since the dilatation tube 110 is housed in the aorta 20 in the expanded configuration, the dilatation tube 110 does not span the aortic valve 30. Thus, when the blood pump 10 enters or exits the patient, the dilatation tube 110 in the expanded state does not pass through the aortic valve 30, so that the dilatation tube 110 is not easy to squeeze and expand the aortic valve 30, and damage to the aortic valve 30 caused by the blood pump 10 is reduced.

Fig. 12 shows a second embodiment of the blood pump of the present application. This second embodiment differs from the first embodiment described above in that the blood pump 10 of the second embodiment uses a conventional impeller 400B having a small diameter D ₄ as usual. The diameter D ₄ of the impeller 400B is smaller than the diameter D ₃, i.e., D ₄＜D₃, of the impeller 400A. Impeller 400B is also a non-deployable rigid impeller. That is, the impeller 400B has a constant shape, and the shape of the impeller 400B is not deformed before and after the blood pump enters the patient.

Since the diameter D ₄ of the impeller 400B is small (D ₄＜D₃), the initial width K ₁ of the radial gap 102 is not 0mm, i.e., K ₁ >0mm, in the initial configuration of the flash tube 110. After the dilatation tube 110 is expanded from the initial configuration to the expanded configuration, the width of the radial gap 102 increases from the initial width K ₁ to the final width K ₂, as is apparent from K ₂＞K₁. Because the width of the radial gap 102 becomes larger, when the impeller 400B is started to rotate subsequently, blood cells can smoothly pass through the radial gap 102, and the blood cells cannot be jammed in the radial gap 102, so that the blood cells are not easily scratched by the blades 420 of the impeller 400B, and hemolysis can be reduced.

It can be seen that in the blood pump 10 of the present application, the dilatation tube 110 of the pump housing 100 includes a first shape memory material such that the dilatation tube 110 has an initial shape and an expanded shape that expands relative to the initial shape, and the first shape memory material is capable of deforming under blood temperature conditions to expand the dilatation tube 110 from the initial shape to the expanded shape, thereby increasing the inner diameter of the dilatation tube 110. Thus, even though the conventional impeller 400B having the small diameter D ₄ is used as usual in the blood pump 10, after the expansion tube 110 is expanded from the initial state to the expanded state, 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, and blood cells can not be jammed in the radial gap 102, thereby greatly reducing the damage of the impeller 400B to blood cells passing through the radial gap 102 and reducing hemolysis.

As can be seen from the first embodiment and the second embodiment, by providing the dilatation tube 110 with a first shape memory material, which is capable of deforming under blood temperature conditions to expand the dilatation tube 110 from the initial state to the expanded state, the damage of the blood pump 10 to blood cells can be reduced and hemolysis can be reduced by using either the rigid impeller 400A with the large diameter D ₃ or the rigid impeller 400B with the small diameter D ₄ for the blood pump 10, so that the dilatation tube 110 has an initial state and an expanded state relative to its initial state.

As previously described, the impeller 400B in the second embodiment is also a non-deployable rigid impeller. That is, the impeller 400B has a constant shape, and the shape of the impeller 400B is not deformed by the temperature of the blood before and after the blood pump 10 enters the patient. Preferably, the shape of the dilatation tube 110 in the initial configuration is a circular tube, so that the dilatation tube 110 can accommodate the rigid impeller 400B.

As shown in fig. 12 (a), in the present embodiment, the initial width K ₁ of the radial gap 102 between the inner wall surface 103 of the flash tube 110 and the impeller 400B may be set to at least 0.08mm. Such as an initial width K ₁ may be 0.08mm to 0.2mm, i.e., 0.08mm < K ₁ < 0.2mm. The initial width K ₁ may take the values of, but is not limited to, 0.09mm, 0.1mm, 0.12mm, 0.15mm, 0.18mm, 0.2mm.

Normally, the dilatation tube 110 is able to normally expand to an expanded configuration when reaching a target location (such as the end of the aorta 20 adjacent to the aortic valve 30) such that the width of the radial gap 102 increases from an initial width K ₁ to a final width K ₂. If an unexpected situation occurs when the dilatation tube 110 reaches the target position, for example, the dilatation tube 110 is not expanded or the expansion amplitude is small, this may result in that the dilatation tube 110 is not completely restored to the expanded configuration. At this time, since the impeller 400B is a rigid impeller and the width of the radial gap 102 is at least 0.08mm, the initial width K ₁ of the radial gap 102 is sufficient to allow the impeller 400B to stably rotate within the dilatation tube 110 and to allow blood to flow through the dilatation tube 110 without disabling the whole blood pump 10 from being paralyzed even if the dilatation tube 110 is not restored to the expanded configuration.

As shown in fig. 12 (B), in the expanded configuration of the flash tube 110, the final width K ₂ of the radial gap 102 between the inner wall surface 103 of the flash tube 110 and the impeller 400B is greater than 0.08mm, i.e., K ₂ >0.08mm. In the case of K ₂＞K₁, the final width K ₂ may be set to 0.08mm < K ₂.ltoreq.0.3 mm. The final width K ₂ may take the values of, but is not limited to, 0.09mm, 0.1mm, 0.12mm, 0.15mm, 0.18mm, 0.2mm, 0.25mm, 0.28mm, 0.3mm, etc. Preferably, 0.1mm < K ₂.ltoreq.0.3 mm.

Fig. 13 to 26 show a third embodiment of the blood pump of the present application. Referring to fig. 13, in the third embodiment, the third embodiment is different from the first embodiment in that an impeller 400C employed in the blood pump 10 is a deformable impeller. Specifically, the impeller 400C includes a second shape memory material to provide the impeller 400C with an initial configuration and an expanded configuration that expands relative to its initial configuration. The second shape memory material is capable of deforming under blood temperature conditions to cause the impeller 400C to expand from an initial configuration to an expanded configuration.

It will be appreciated that the second shape memory material is capable of automatically returning to its pre-heat-treated shape upon heating to a desired temperature (such as blood temperature) after plastic deformation by heat treatment. Therefore, for the impeller 400C including the second shape memory material, the expanded shape of the impeller 400C is a shape before heat treatment and is also a prefabricated working shape, and the impeller 400C in the expanded shape is subjected to plastic deformation after heat treatment, and the blades 420 of the impeller 400C are contracted or folded, so that the impeller 400C is deformed from the expanded shape to the initial shape. This initial configuration is also the configuration that the impeller 400C assumes during the period from after the heat treatment to before it enters the patient. When the impeller 400C in the initial configuration is heated to a desired temperature (such as blood temperature), the impeller 400C expands from the initial configuration to automatically recover to the expanded configuration (i.e., the operating configuration).

Wherein, the blood temperature generally refers to the blood temperature of a normal human body, such as 36 ℃ to 37.5 ℃. However, to ensure that the impeller 400C can also expand normally in some patients with low or high blood temperatures, the second shape memory material is deformed at a temperature of 34 ℃ to 39 ℃, so that the impeller 400C can expand from the initial configuration to the expanded configuration at a blood temperature in the range of 34 ℃ to 39 ℃.

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 realize transition temperature control by adjusting molecular structure. The shape memory polymer may be PLC, PU, PLA, or the like. The shape memory alloy can realize transition temperature control by adjusting alloy components. The shape memory alloy may be a nickel-containing alloy, a titanium-containing alloy, or the like. It should be noted that the first shape memory material should be selected to be harmless to the human body and applicable to the human body. In particular, in this embodiment, impeller 400C is formed from a shape memory alloy, such as a nickel titanium alloy. This may provide the impeller 400C with a certain hardness, ensuring that the impeller 400C can rotate stably.

Referring to fig. 14 and 15, and fig. 20 and 21, after the impeller 400C is expanded from the initial configuration to the original expanded configuration, the blades 420 of the impeller 400C are unfolded, so that the diameter of the impeller 400C becomes large.

Referring to fig. 13 (a) or 17, the diameter of the impeller 400C in the initial configuration is denoted as the initial diameter D _5a. Referring to fig. 13 (b) or 23, the diameter of the impeller 400C in the expanded configuration is denoted as the working diameter D _5b, and there is D _5b＞D_5a. This may allow the impeller 400C to achieve a larger diameter, thereby allowing the impeller 400C to have higher hydraulic performance. In this case, the rotation speed of the impeller 400C can be reduced within a certain range, and the hydraulic performance of the blood pump 10 can be satisfied. As the rotation speed of the impeller 400C is reduced, the blades 420 of the impeller 400C collide with and damage blood cells, effectively reducing hemolysis.

Referring to fig. 14-16, when the blood pump 10 is pushed into the body through the wound, both the dilatation tube 110 and the impeller 400C enter the body in the initial configuration. Referring to fig. 20-22, the blood pump 10 is advanced through the aorta 20 to the left ventricle 40 such that the distal end of the blood pump 10 is positioned within the left ventricle 40 and the dilatation tube 120 and proximal opening 101 are both housed in the aorta 20. After the flash tube 110 and the impeller 400C are in contact with the blood, the heat of the blood gradually heats the impeller 400C and the flash tube 110, and the impeller 400C and the flash tube 110 gradually expand when reaching the blood temperature, so that the impeller 400C and the flash tube 110 automatically recover from the initial form to the expanded form, the diameter of the impeller 400C is increased, and the inner diameter of the flash tube 110 is also increased, so that the flash tube 110 can accommodate the impeller 400C after the blades 420 are expanded.

Since the impeller 400C includes a second shape memory material, the second shape memory material is capable of deforming under blood temperature conditions, thereby expanding the impeller 400C from an initial configuration to an expanded configuration. That is, the second shape memory material is deformed by temperature stimulation. Thus, the second shape memory material does not deform when the second shape memory material is not subjected to a corresponding temperature stimulus. Based on this, when the impeller 400C is not stimulated by the corresponding temperature (e.g., blood temperature) in the initial configuration, the impeller 400C can maintain the folded shape relative to the expanded configuration without an external force. I.e., the original form of the impeller 400C is maintained without an external force. The impeller 400C may have a small diameter in the initial state and may be accommodated in the expansion tube 110 in the initial state. The impeller 400C may thus be maintained in the collapsed, conventional configuration relative to the expanded configuration without the need for external compression by the sheath. The impeller 400C can then be gradually inflated to an expanded configuration after the impeller 400C is stimulated by the blood temperature.

It is understood that when both the flash tube 110 and the impeller 400C are in the initial configuration, the initial width K ₁ of the radial gap 102 between the impeller 400C and the inner wall surface 103 of the flash tube 110 may be 0mm or greater than 0mm, i.e., K ₁. Gtoreq.0 mm. After the dilatation tube 110 and impeller 400C return to the expanded configuration, the width of the radial gap 102 increases from the initial width K ₁ to the final width K ₂, and the final width K ₂ is sufficient to allow the impeller 400C to rotate stably without contacting the inner wall surface 103 of the dilatation tube 110.

In particular, when the initial width K ₁ is 0mm, after the dilatation tube 110 and the impeller 400C are restored to the expanded configuration, the working diameter D _5a of the impeller 400C will be larger than the contracted inner diameter D _1a of the dilatation tube 110 in the initial configuration, so that the impeller 400C obtains a larger diameter, greatly improves the hydraulic performance of the impeller 400C, and further can reduce the rotation speed of the impeller 400C under the condition of meeting the hydraulic performance requirement of the blood pump 10, so that the blades 420 of the impeller 400C are not easy to collide and damage blood cells, and effectively reduce hemolysis. Optionally, therefore, the flash tube 110 has a contracted inner diameter D _1a when in the initial configuration, and the impeller 400C has an initial diameter D _5a that is greater than or equal to the contracted inner diameter D _1a, D _5a≥D_1a.

Alternatively, in the expanded configuration of the flash tube 110, the width K ₂ of the radial gap 102 between the inner wall surface 103 of the flash tube 110 and the impeller 400C may be 0.08 mm-0.3 mm, i.e., 0.08 mm. Ltoreq.K ₂. Ltoreq.0.3 mm. Still alternatively, the value of 0.1 mm.ltoreq.K ₂≤0.3mm.K₂ may be, but is not limited to, 0.09mm, 0.1mm, 0.12mm, 0.15mm, 0.18mm, 0.2mm, 0.25mm, 0.28mm, 0.3mm, etc.

Referring to fig. 14-16, the pump housing 100 further includes a proximal tube 120, the proximal tube 120 being connected to the proximal end of the flash tube 110, the proximal tube 120 being provided with a proximal opening 101, the proximal tube 120 being of non-deformable construction. The proximal tube 120 has a certain stiffness. I.e., the proximal tube 120 is not deformed by blood after it has entered the body. In this way, the proximal tube 120 has a relatively strong hardness, so as to improve the connection firmness of the proximal tube 120 and the driving unit 500, and the connection position of the two is not easy to loosen and fall off.

Preferably, the working diameter D _5a of the impeller 400C is greater than the inner diameter of the proximal tube 120. This allows the impeller 400C to achieve a larger diameter, and thus the hydraulic performance of the impeller 400C is higher. Under the condition that the requirement of the blood pump 10 on the hydraulic performance is met, the rotating speed of the impeller 400C can be reduced to a large extent, and further the damage to blood cells caused by the rotation of the impeller 400C is reduced.

Referring to fig. 14-16, pump housing 100 further includes a distal tube 130, distal tube 130 being connected to the distal end of dilatation tube 110, distal tube 130 being of non-deformable construction. I.e., the distal tube 130 is not deformed by blood after it has entered the body. The distal tube 130 may be connected to a cannula assembly 200 having a distal opening 201. Of course, in other embodiments, the distal opening 201 may also be provided directly in the distal tube 130.

Preferably, the initial diameter D _5a is greater than the inner diameter of the distal tube 130. This allows the impeller 400C to achieve a larger diameter, and thus the hydraulic performance of the impeller 400C is higher. Under the condition that the requirement of the blood pump 10 on the hydraulic performance is met, the rotating speed of the impeller 400C can be reduced to a large extent, and further the damage to blood cells caused by the rotation of the impeller 400C is reduced.

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.

In a first embodiment of the blood pump such as shown in fig. 1-11, a second embodiment of the blood pump shown in fig. 12, or a third embodiment of the blood pump shown in fig. 13-26, the blood pump 10 may further comprise any of a cannula assembly 200, a catheter 300, and a drive unit 500. The pump housing 100 of the blood pump 10 may further include either of a proximal tube 120 and a distal tube 130. The dilatation tubes 110 of the pump housing 100 may each be provided with a deformation hole 11a, a deformation flap 11b and a flexible membrane located in the deformation hole 11 a. For avoiding redundancy, the following description will mainly take the blood pump 10 of the embodiment shown in fig. 14 to 26 as an example, and the blood pump 10 of other embodiments may be implemented correspondingly, and will not be separately listed here.

Referring to fig. 14 to 15 and 18, the dilatation tube 110 of the blood pump 10 is provided with a deformation hole 11a, and the deformation hole 11a can make the dilatation tube 110 have higher ductility, so that the dilatation tube 110 is easier to deform under heat. The deformation holes 11a provide a contraction space for the wall contraction of the dilatation tube 110 during the heat treatment contraction of the dilatation tube 110 from the expanded configuration to the initial configuration. In the process of expanding the dilatation tube 110 from the initial shape to the expanded shape under the influence of the blood temperature, the deformation holes 11a can reduce the stress of the tube wall of the dilatation tube 110, so that the dilatation tube 110 is easier to be heated and expanded.

Referring to fig. 14 to 15 and 18, the deformation hole 11a is elongated. The deformation hole 11a extends in the axial direction of the pump case 100. Specifically, the deformation hole 11a has a first width W ₁ extending in the circumferential direction of the pump casing 100, and a first length L ₁ extending in the axial direction of the pump casing 100, the first length L ₁ being greater than the first width W ₁. This may allow for easier radial expansion of the flash tube 110 to increase the diameter of the flash tube 110. Of course, in other embodiments, the shape of the deformation hole 11a may be elliptical, corrugated or slit, and the length direction of the deformation hole 11a may be the same as the axial direction of the pump casing 100.

Referring to fig. 16 to 18, the number of the deformation holes 11a may be plural. The plurality of deformation holes 11a are arranged at intervals in the circumferential direction of the dilatation tube 110. Of course, in other embodiments, there may be only one deformation hole 11a.

Referring to fig. 16 to 18, alternatively, a plurality of deformation holes 11a are arranged at equal intervals in the circumferential direction of the dilatation tube 110. In this way, the stress or strength of the pipe walls of the expansion pipe 110 at two sides of the deformation hole 11a is approximately the same, so that when the expansion pipe 110 is deformed, all the positions of the circumference of the expansion pipe 110 shrink or expand in the radial direction equally, the shape of the pipe before and after the deformation is ensured, and further the uniform radial gap 102 is ensured between the inner wall surface 103 of the expansion pipe 110 and the impeller 400 along the circumferential direction. The number of the deformation holes 11a may be 2 to 6. Such as the number of deformation holes 11a may be, but not limited to, 2, 3 or 4.

Referring to fig. 16 to 18, a flexible film (not shown in the drawings) covering the deformation holes 11a is further provided in the deformation holes 11 a. In the initial configuration of the dilatation tube 110, the flexible membrane may be contracted or folded in the deformation holes 11 a. The dilatation tube 110 is capable of stretching or expanding the flexible membrane in the circumferential direction of the pump housing 100 when returning from the initial configuration to the expanded configuration. Since the flexible membrane covers the deformation hole 11a, it is ensured that when the impeller 400C drives blood to flow through the dilatation tube 110 after the dilatation tube 110 is expanded to the expanded state, a higher pressure is formed in the dilatation tube 110, which contributes to an improvement of the blood flow rate.

Preferably, the periphery of the flexible film is fixedly connected with the periphery of the deformation hole 11a, so that the flexible film is not easy to fall off. For example, the peripheral edge of the flexible film and the peripheral edge of the deformation hole 11a may be bonded by adhesive or heat-fused. The peripheral edge of the flexible membrane is also in sealing connection with the peripheral edge of the deformation hole 11a to sealingly cover the deformation hole 11a so that blood cannot flow out of the deformation hole 11 a. The material of the flexible membrane may be a teflon material. Such as the flexible membrane may be selected to be a PTFE membrane.

Referring to fig. 16 to 18, a deformation flap 11b extending in the axial direction of the pump casing 100 is formed between adjacent two deformation holes 11 a. The deformation flap 11b is a part of the wall of the dilatation tube 110. The deformation flap 11b has a second width W ₂ extending a distance in the circumferential direction of the pump casing 100. In the present embodiment, in the initial configuration of the dilatation tube 110, the second width W ₂ of the deformation flap 11b is larger than the first width W ₁ of the deformation hole 11a, i.e. W ₂＞W₁. Or the second width W ₂ is greater than the radial thickness of the deformation flap 11b. This allows the deformation flap 11b to have a larger cross-sectional area without occupying the radial space of the dilatation tube 110, so that the deformation flap 11b, i.e. the dilatation tube 110, has a certain stiffness. On the one hand, the dilatation tube 110 can better maintain the contracted shape relative to the expanded shape in the initial shape, so that the dilatation tube 110 can enter the body in the initial shape and is not easy to be extruded and collapsed by the tissue in the body. On the other hand, when the dilatation tube 110 is stimulated by the blood temperature, the dilatation tube 110 gradually expands from the initial state to the expanded state, so that the dilatation tube 110 can be prevented from expanding from the initial state to the expanded state too quickly after being stimulated by the blood temperature.

In addition, after the dilatation tube 110 is inflated to the expanded configuration, the second width W ₂ of the deformation flap 11b is also larger. The deformed flap 11b of the dilatation tube 110 in the expanded configuration has a hardness that is relatively high compared to a wire-shaped elastic wire, so that the deformed flap 11b is less likely to collapse and contact the impeller 400C.

Alternatively, the cross section of the deformation flap 11b taken by a plane perpendicular to the central axis of the pump housing 100 is arc-shaped, non-circular. In the initial state of the expansion tube 110, the deformation flap 11b is a part of the wall of the cylindrical tube, and the second width W ₂ of the deformation flap 11b is constant in the axial direction of the pump casing 100. In the expanded configuration, the second width W ₂ is gradually reduced from the middle portion thereof toward both ends in the axial direction thereof, so that the deformation flap 11b takes the shape of an arc, a boat, a crescent, or the like protruding outwardly with respect to the central axis of the pump casing 100.

Optionally, the number of deformation flaps 11b is 2 to 4. The number of deformation flaps 11b corresponds to the number of deformation holes 11 a. The number of deformation flaps 11b may be 2, 3 or 4, for example. Since the plurality of deformation holes 11a are uniformly spaced in the circumferential direction of the dilatation tube 110, the second widths W ₂ of the plurality of deformation lobes 11b are substantially the same. When the expansion pipe 110 is deformed, the deformation flaps 11b shrink or expand equally in the radial direction, so that the expansion pipe 110 is a cylindrical pipe before and after deformation, and further, uniform radial clearance between the inner wall surface 103 of the expansion pipe 110 and the impeller 400 in the circumferential direction is ensured.

Referring to fig. 18, the outer diameter of the dilatation tube 110 in the initial configuration is denoted as the contracted outer diameter D _2a and the second width W ₂ of the deformation flap 11b may be W ₂≥0.25×π×D_2a. By the arrangement, the deformation flap 11b can be ensured to have a larger width, so that the pipe wall of the dilatation pipe 110 has better strength, and the dilatation pipe 110 is ensured to have higher strength before and after deformation and is not easy to be extruded and deformed by external force.

Alternatively, 0.25 x pi x D _2a≤W₂≤0.5×π×D_2a.

Referring to fig. 16 and 18, the dilatation tube 110 comprises a main tube section 111 and a first tube section 112, the first tube section 112 being connected to the proximal end of the main tube section 11. Referring to fig. 24-26, in the expanded configuration, the diameter of the first tube segment 112 gradually decreases in the distal-to-proximal direction of the pump housing 100. Thus, the first tube segment 112 has a certain inclination, on one hand, the inner wall surface 103 of the first tube segment 112 forms a conical guide surface, which can guide blood to flow from the main tube segment 111 to the first tube segment 112 so as to facilitate the blood to be discharged from the proximal opening 101 close to the first tube segment 112, and on the other hand, the outer wall surface of the first tube segment 112 forms a conical reducing surface, which is beneficial to reducing the difficulty of removing the dilatation tube 110 from the blood vessel in the process of withdrawing the blood pump 10 from the human body.

Referring to fig. 16 and 18, the dilatation tube 110 may also comprise a main tube section 111 and a second tube section 113, the second tube section 113 being connected to the distal end of the main tube section 11. Referring to fig. 24-26, in the expanded configuration, the diameter of the second tube segment 113 gradually decreases in the proximal-to-distal direction of the pump housing 100. The second tube section 113 has a certain inclination, on the one hand, the inner wall surface 103 of the second tube section 113 forms a conical guide surface, so that blood can be guided from the second tube section 113 to enter the main tube section 111, which is beneficial to improving the efficiency of blood flowing to the impeller 400C, and on the other hand, the outer wall surface of the second tube section 113 forms a conical reducing surface, which is beneficial to moving the dilatation tube 110 back and forth to finely adjust the position of the dilatation tube 110 in a blood vessel after the blood pump 10 is pushed into a human body.

Of course, the expansion pipe 110 may have the main pipe section 111, the first pipe section 112, and the second pipe section 113 at the same time.

Referring to fig. 16, the impeller 400C has a hub 410 and blades 420 disposed on the hub 410. The vane 420 has a second length L ₂ extending in the axial direction of the pump housing 100, and the first length L ₁ is greater than the second length L ₂ (i.e., L ₁＞L₂) such that both ends of the deformation holes 11a extend beyond both ends of the vane 420. This allows the wall of the dilatation tube 110 and the vane 420 to be effectively deformed in the radial direction, and ensures that the radial gap 102 between any one of the outer edges of the vane 420 and the inner wall surface 103 of the dilatation tube 110 after expansion can be increased.

Referring to fig. 16, the vane 420 is fully received within the flash tube 110. The proximal ends of the blades 420 are spaced from the proximal end of the flash tube 110 by a first distance ΔL ₁ in the axial direction of the pump housing 100. Since the deformation of the first tube section 112 of the dilatation tube 110 is slightly smaller than the deformation of the main tube section 111, the contact between the blades 420 and the proximal end of the dilatation tube 110 can be avoided by spacing the proximal ends of the blades 420 and the proximal end of the dilatation tube 110 by the first distance Δl ₁ along the axial direction of the pump housing 100.

Similarly, the distal ends of the blades 420 are spaced from the distal end of the flash tube 110 by a second distance ΔL ₂ along the axial direction of the pump casing 100. Since the deformation of the second tube section 113 of the dilatation tube 110 is slightly smaller than the deformation of the main tube section 111, the distal ends of the blades 420 and the distal ends of the dilatation tube 110 are spaced apart from each other by the second distance Δl ₂ along the axial direction of the pump casing 100, so that the blades 420 and the distal ends of the dilatation tube 110 can be prevented from being interfered by contact.

Referring to fig. 14-16, the proximal end of the pump housing 100 is provided with a proximal opening 101. The distal end of the blood pump 10 is provided with a distal opening 201. Referring to fig. 28, when the blood pump 10 is advanced to the left ventricle 40 via the aorta 20, the distal opening 201 of the blood pump 10 is distally located within the left ventricle 40, while the proximal opening 101 is located within the aorta 20. Blood from the left ventricle 40 flows from the distal opening 201 of the blood pump 10 into the blood flow path within the pump housing 100 and out of the proximal opening 101 to the aorta 20 to assist the left heart in pumping blood.

Referring to fig. 14-16, the blood pump 10 further includes a cannula assembly 200, the cannula assembly 200 including a cannula 210, the proximal end of the cannula 210 being fixedly secured to the distal end of the pump housing 100. The lumen of cannula 210 forms a blood flow path. The cannula assembly 200 may also include a distal tube 220, the distal tube 220 being provided with a distal opening 201. Wherein the cannula 210 is a flexible tube that can be bent to conform to the shape of the blood vessel. The cannula 210 may be a straight tube in its natural state or may be a bent tube having a predetermined bending angle. After the blood pump 10 is pushed into the body, the cannula 210 extends across the aortic valve 30 into the left ventricle 40 through the aorta 20 such that the distal opening 201 is located in the left ventricle and the dilatation tube 110 and the proximal opening 101 of the pump housing 100 are both located in the aorta 20.

It will be appreciated that the distal tube 220 is not required. In other embodiments, the distal opening 201 may be opened directly at the distal end of the cannula 210. Of course, the blood pump 10 may eliminate the entire cannula assembly 200. Because the dilatation tube 110 of the pump housing 100 has a larger diameter after the dilatation tube 110 has been expanded to the expanded configuration, the dilatation tube 110 may be adapted to be positioned in the aorta 20. In this manner, the blood pump 10 omits the cannula assembly 200 and opens the distal opening 201 directly at the distal end of the pump housing 100. The distal end of pump housing 100 need only extend slightly into left ventricle 40 so that distal opening 201 of pump housing 100 enters left ventricle 40 without being inserted into the bottom support position of left ventricle 40 by cannula assembly 200.

Referring to fig. 14 to 16, the blood pump 10 further includes a driving unit 500, and the driving unit 500 can drive the impeller 400C to rotate. The driving unit 500 is fixedly coupled to the proximal end of the pump housing 100 and can be inserted into a blood vessel of a patient together with the pump housing 100.

Referring to fig. 14 to 16, the driving unit 500 includes a housing 510 and a rotation shaft 520. The casing 510 is connected to the pump casing 100, the rotary shaft 520 is rotatably mounted to the casing 510, and the rotary shaft 520 penetrates the casing 510 to have a connection end 521 accommodated in the pump casing 100, and the connection end 521 is fixedly connected to the impeller 400C. Specifically, the connection end 521 is fixedly connected with the hub 410 of the impeller 400C. The proximal opening 101 of the pump housing 100 is typically disposed adjacent the distal end of the housing 510.

Referring to fig. 14 to 16, the driving 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 axially spaced apart. The rotating shaft 520 rotatably penetrates the stator 530, and the rotating shaft 520 is fixedly connected with the rotor 540. The number of stators 530 may be one or two or more, and the number of rotors 540 may be one or two or more. The stator 530 is operable to generate a rotating magnetic field that rotates at least one rotor 540, and the rotor 540 rotates the shaft 520 under the rotating magnetic field, and the impeller 400C rotates accordingly.

Of course, the driving unit 500 may not include the rotor 540 and the stator 530. In other embodiments, the drive unit 500 may include a coupling housed within the housing 510 and a flexible shaft (not shown) having a proximal end connected to the external motor and a distal end connected to the coupling, the coupling connecting to a proximal end of the shaft 520. Thus, the external motor drives the flexible shaft to rotate by driving the flexible shaft, so that the flexible shaft drives the rotating shaft 520 to rotate together by the coupling. The coupling may be a magnetic coupling or a conventional coupling. Such as a magnetic coupling, comprising a driving magnet and a driven magnet, wherein the driving magnet is fixedly connected with the flexible shaft, the driven magnet is fixedly connected with the proximal end of the rotating shaft 520, and the driving magnet and the driven magnet have magnetic attraction force which is mutually attracted.

Referring to fig. 14 to 16 and 18, the proximal tube 120 of the pump housing 100 is fixedly connected with the housing 510 of the drive unit 500, the proximal tube 120 being provided with a proximal opening 101. Optionally, proximal tube 120 is of unitary construction with dilatation tube 110. The proximal tubing 120 may be the same material as the dilatation tube 110 or a different material. For example, both the proximal tube 120 and the dilatation tube 110 are made of memory-shaped metal materials. However, since the proximal tube 120 is not subjected to plastic deformation during manufacturing, the proximal tube 120 does not have an initial shape or an expanded shape, and thus the proximal tube 120 is not deformed when it encounters blood, and the junction between the proximal tube 120 and the drive unit 500 is secured, and is not easily detached.

Referring to fig. 16 and 18, a first fold T ₁ is formed at the junction of the first tube segment 112 and the proximal tube 120 of the dilatation tube 110, and a second fold T ₂ is formed at the junction of the first tube segment 112 and the main tube segment 111. Referring to fig. 22 and fig. 24 to fig. 26, when the dilatation tube 110 is deformed from the initial configuration to the expanded configuration, the dilatation tube 110 is bent and deformed at the first crease T ₁ and the second crease T ₂, so that the diameter of the first tube section 112 gradually increases from the first crease T ₁ to the second crease T ₂ in the expanded configuration of the dilatation tube 110.

Referring to fig. 19, the outer diameter of the flash tube 110 in the initial configuration is optionally noted as a contracted outer diameter D _2a, which contracted outer diameter D _2a is the same as the outer diameter D ₆ of the proximal tube 120. I.e., D _2a＝D₆. This allows the internal volume of the flash tube 110 in its initial configuration to be sufficiently large to ensure that it can accommodate either the impeller 400A or the impeller 400C having a larger diameter. On the other hand, the outer surface of the dilatation tube 110 and the outer surface of the proximal tube 120 may be located on the same cylindrical surface, and the outer surfaces of the two may be joined relatively smoothly.

Referring to fig. 19 and 25, alternatively, the outer diameter of the dilatation tube 110 in the expanded configuration is denoted as an expanded outer diameter D _2b, and the ratio of the expanded outer diameter D _2b to the outer diameter D ₆ of the proximal tube 120 is 1.1-1.5. That is, D _2b/D₆ is 1.1.ltoreq.D 1.5. The ratio may be, but is not limited to, specifically 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.49, etc. This prevents the outer diameter of the dilatation tube 110 from becoming too large in the expanded configuration.

Referring to fig. 14-16 and 18, distal tube 130 of pump housing 100 is fixedly secured to the proximal end of cannula 210. Distal tube 130 is a non-deformable structure. The distal tube 130 has a certain hardness. Optionally, distal tube 130 is of unitary construction with dilatation tube 110. The distal tube 130 may be the same material as the dilatation tube 110 or a different material. For example, the distal tube 130 and the dilatation tube 110 are both made of memory-shaped metal materials. However, during manufacturing, since the distal tube 130 is not subjected to plastic deformation treatment, the distal tube 130 does not have an initial shape and an expanded shape, and thus the distal tube 130 is not deformed when it encounters blood, and the joint between the distal tube 130 and the cannula 210 is secured, and is not easily detached.

Referring to fig. 18 and 24 to 26, a third fold T ₃ is formed at the junction of the second tube section 113 and the distal tube 130 of the dilatation tube 110, and a fourth fold T ₄ is formed at the junction of the second tube section 113 and the main tube section 111. When the dilatation tube 110 is deformed from the initial configuration to the expanded configuration, the dilatation tube 110 is bent and deformed at the third crease T ₃ and the fourth crease T ₄, so that the diameter of the second tube section 113 is gradually increased from the third crease T ₃ to the fourth crease T ₄ in the expanded configuration of the dilatation tube 110.

Referring to fig. 19, the outer diameter of the flash tube 110 in the initial configuration is denoted as a contracted outer diameter D _2a, which contracted outer diameter D _2a is the same as the outer diameter D ₇ of the distal tube 130. I.e., D _2a＝D₆. On the one hand, the diameter of the expansion pipe 110 in the initial state can be made larger, so that the internal space of the expansion pipe 110 is larger, and the impeller 400C with a larger diameter can be accommodated. On the other hand, the outer surface of the dilatation tube 110 and the outer surface of the proximal tube 120 may be located on the same cylindrical surface, and the outer surfaces of the two may be joined relatively smoothly.

Referring to fig. 19 and 25, alternatively, the outer diameter of the dilatation tube 110 in the expanded configuration is denoted as an expanded outer diameter D _2b, and the ratio of the expanded outer diameter D _2b to the outer diameter D ₇ of the distal tube 130 is 1.1-1.5. That is, D _2b/D₇ is 1.1.ltoreq.D 1.5. The ratio may be, but is not limited to, specifically 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.49, etc. This prevents the outer diameter of the dilatation tube 110 from becoming too large in the expanded configuration.

It will be appreciated that the proximal tube 120 is not required. The proximal opening 101 may be provided at the proximal end of the dilatation tube 110, i.e. the proximal opening 101 is provided on the first tube section 111, the proximal end of the first tube section 111 being fixedly connected with the housing 510 of the drive unit 500. The distal tube 130 is also optional and may be connected to the cannula 210 by the distal end of the dilatation tube 110.

Referring to fig. 14-16, the blood pump 10 further includes a catheter 300, the catheter 300 being connected to the proximal end of the drive unit 500. The catheter 300 has an interior lumen, and the interior lumen of the catheter 300 can house flush lines, sensor fibers, wires of the stator 530, and the like.

Referring to fig. 14 and 15, the blood pump 10 further includes a pressure sensor 600, and the pressure sensor 600 is used to detect the blood pressure. In some conventional techniques, the pressure sensor 600 is secured to the pump housing 100 using adhesive. Here, it is considered that if the pressure sensor 600 is still mounted to the pump casing 100 in the present embodiment, the pressure sensor 600 may be pulled when the capacity expansion pipe 110 of the pump casing 100 expands and deforms, and there is a risk of the adhesive of the pressure sensor 600 falling off.

Therefore, in the present embodiment, the pressure sensor 600 is mounted on the driving unit 500, so that the pressure sensor 600 is not pulled when the dilatation tube 110 of the pump casing 100 expands, and the pressure sensor 600 is not easily separated, and the mounting is more stable.

Specifically, the pressure sensor 600 includes a probe and an optical fiber connected to the probe, and the optical fiber is accommodated in the catheter 300. The probe is mounted inside the housing 510 of the drive unit 500. The side wall of the housing 510 is provided with a detection window, and the probe corresponds to the detection window so as to be capable of sensing blood pressure.

Referring to fig. 29, the present application also provides a manufacturing method of the pump housing 100 of the blood pump 10:

In the first step, as shown in fig. 29 (a), a cylindrical tube M made of a shape memory material is taken.

In the second step, as shown in fig. 29 (b), the proximal tube 120, the distal tube 130, and the dilatation tube 110 between the proximal tube 120 and the distal tube 130, which are axially arranged, are divided as desired on the cylindrical tube M.

Specifically, the dilatation tube 110 further divides a first portion P ₁, a second portion P ₂, and a third portion P ₃ disposed between the first portion P ₁ and the second portion P ₂, the first portion P ₁ being connected to the proximal tube 120, and the second portion P ₂ being connected to the distal tube 130.

Third, as shown in fig. 29 (c), the dilatation tube 110 of the cylindrical tube M is radially expanded, and the proximal tube 120 and the distal tube 130 remain unexpanded, so that only the dilatation tube 110 attains an expanded configuration.

Specifically, the third portion P ₃ of the expansion pipe 110 is radially expanded to form the main pipe section 111, in which process the diameter of the first portion P ₁ is gradually increased from the distal end of the proximal pipe 120 toward the main pipe section 111 so that the first portion P ₁ forms the first pipe section 112, and the diameter of the second portion P ₂ is gradually increased from the proximal end of the distal pipe 130 toward the main pipe section 111 so that the second portion P ₂ forms the second pipe section 113 of the expansion pipe 110. A first crease T ₁ and a second crease T ₂ are formed at both ends of the first tube segment 112, respectively, and a third crease T ₃ and a fourth crease T ₄ are formed at both ends of the second tube segment 113, respectively.

Fourth, as shown in fig. 29 (d), the pump casing 100 is heat-treated, and the expansion tube 110 of the pump casing 100 is compressed to the original shape after the heat treatment. Since the proximal tube 120 and the distal tube 130 are not expanded in the third step, the proximal tube 120 and the distal tube 130 are not deformed when heat-treated in this fourth step. The dilatation tube 110 is contracted to approximately the same size as the proximal tube 120, the distal tube 130, so that the dilatation tube 110 of the pump housing 100 attains an initial shape. In this configuration, the three tubes, proximal tube 120 and distal tube 130 and dilatation tube 110, are approximately one cylindrical tube.

After the pump casing 100 is subjected to the above-described fourth step, the dilatation tube 110 can be stably maintained in the original form without heating. After the pump housing 100 is pushed into the body with the blood pump 10 in this configuration, the dilatation tube 110 of the pump housing 100 gradually expands to return to the expanded configuration under the influence of the blood temperature.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the claims. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims

1. A blood pump, the blood pump comprising:

a pump housing provided with a proximal opening, and

An impeller rotatably disposed within the pump housing, wherein,

The pump housing includes a flash tube housing the impeller, the flash tube including a first shape memory material having an initial configuration and an expanded configuration that expands relative to the initial configuration, the first shape memory material being capable of deforming under blood temperature conditions to expand the flash tube from the initial configuration to the expanded configuration.

2. The blood pump of claim 1, wherein the flash tube further 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 34-39 ℃;

the shape of the dilatation tube in the initial form is a circular tube;

The initial shape of the expansion tube is maintained without external force;

3. The blood pump of claim 1, wherein the impeller comprises a second shape memory material, the impeller also having an initial configuration and an expanded configuration that expands relative to its initial configuration, the second shape memory material being capable of deforming under blood temperature conditions to expand the impeller from the initial configuration to the expanded configuration.

4. A blood pump according to claim 3, wherein the impeller further 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 34-39 ℃;

The initial form of the impeller is maintained without external force.

5. A blood pump according to claim 3, wherein the dilatation tube has an inner diameter of a contracted inner diameter D _1a in an initial configuration, the impeller has an initial diameter D _5a in an initial configuration, and the impeller has an operating diameter D _5b in an expanded configuration, wherein D _5b＞D_5a and D _5b≥D_1a.

6. The blood pump of claim 3, wherein the impeller has a diameter in the expanded configuration of an operating diameter D _5b, wherein the pump housing further comprises a proximal tube connected to the proximal end of the flash tube and provided with the proximal opening, wherein the proximal tube is of a non-deformable configuration, wherein the operating diameter D _5b is greater than the inner diameter of the proximal tube, and/or wherein the pump housing further comprises a proximal tube,

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

8. The blood pump of claim 1, wherein a radial gap between an inner wall surface of the flash tube and the impeller is 0.1mm to 0.3mm wide when the flash tube is in an expanded configuration.

9. The blood pump according to any one of claims 1 to 8, wherein the expansion tube is provided with a deformation hole extending in an axial direction of the pump casing, wherein a flexible membrane covering the deformation hole is provided in the deformation hole, and wherein the expansion tube is capable of stretching or expanding the flexible membrane in a circumferential direction of the pump casing when returning from an initial configuration to an expanded configuration.

10. The blood pump according to claim 9, wherein the expansion tube is provided with a plurality of the deformation holes, the plurality of the deformation holes are arranged at intervals along the circumferential direction of the expansion tube, and a deformation flap extending along the axial direction of the pump housing is formed between two adjacent deformation holes.

11. The blood pump of claim 10, wherein the deformation orifice has a first width W ₁ extending circumferentially of the pump housing, the deformation flap has a second width W ₂ extending circumferentially of the pump housing, and the expansion tube has an outer diameter in an initial configuration of a contracted outer diameter D _2a, wherein W ₂＞W₁, and/or W ₂≥0.25πD_2a.

12. The blood pump of claim 10, wherein the flash tube further has at least one of the following characteristics:

The number of the deformation lobes of the dilatation tube is 2-5;

The periphery of the flexible membrane of the dilatation tube is fixedly connected with the periphery of the deformation hole;

13. The blood pump of claim 9, wherein the impeller comprises a hub and blades disposed on the hub, the blades being disposed within the flash tube, wherein,

14. The blood pump of any one of claims 1 to 8, wherein the dilatation tube comprises a first tube section, a second tube section and a main tube section connected between the first tube section and the second tube section, wherein in the dilatation tube in an expanded configuration the diameter of the first tube section gradually decreases in a distal to proximal direction of the pump housing and the diameter of the second tube section gradually decreases in a proximal to distal direction of the pump housing.

15. The blood pump of claim 1, further comprising a drive unit comprising a housing and a shaft coupled to the impeller, the pump housing further comprising a proximal tube coupled to a proximal end of the flash tube, the proximal tube being fixedly coupled to the housing, the proximal tube being provided with the proximal opening, wherein the pump housing further comprises at least one of:

The proximal tube is a non-deformable structure;

the proximal tube and the dilatation tube are of an integrated structure;

16. The blood pump of any one of claims 1-8, wherein the pump housing assembly further comprises a cannula assembly having a blood flow path, wherein the pump housing further comprises a distal tube connected to the distal end of the flash tube, wherein the distal tube is fixedly attached to the proximal end of the cannula assembly, and wherein the pump housing further comprises at least one of the following features:

The distal tube is a non-deformable structure;

The far side pipe and the dilatation pipe are of an integrated structure;