Conduit pump and impeller and pump body thereof

Abstract

Disclosed are a conduit pump and an impeller and a pump body thereof. The impeller can be accommodated in a pump shell of the conduit pump and comprises a hub and blades provided on the hub. The blades have blade roots provided on the hub, blade tips away from the hub, and reverse folding portions between the blade roots and the blade tips. The blade roots extend in a first circumferential direction and tilt towards the reverse folding portions in a radial direction. The reverse folding portions extend in a second circumferential direction opposite to the first circumferential direction and tilt towards the blade tips of the blades in the radial direction.

Description

[0001] This application is a divisional application of application No. "202111436271.8", with a filing date of "November 29, 2021", and with the title of "Catheter pump and impeller and pump body thereof". TECHNICAL FIELD

[0002] The present disclosure relates to the field of medical devices, in particular to a device for cardiac assist use, and more particularly to a catheter pump and impeller and pump body thereof. BACKGROUND

[0003] An interventional catheter pump device (hereinafter referred to as a blood pump) can pump blood. Taking left ventricular assist as an example, the prior art generally places the pump of the interventional catheter pump device in the left ventricle of the subject's body, and drives the impeller of the pump to rotate through a flexible shaft, and drives the flexible shaft through a motor to transmit power to the pump.

[0004] In order to ensure stable contraction and expansion, the existing catheter pump can be inserted into the blood vessels of the patient and can be expanded after insertion. During compression and expansion, the rotor (for example, the impeller) and the shell will deform accordingly, and the stability of the tip clearance size (also known as the pump gap, that is, the interval gap between the radial outer end of the impeller and the inner wall of the pump body shell) is an important factor affecting the stability of the blood pump. Through simulation analysis, the size change of the pump body external support (shell) is small, and the greatest influence on the tip clearance is the change of the outer diameter of the impeller.

[0005] As the rotational speed increases, the outer diameter of the impeller continues to increase, and the continuous increase of the outer diameter of the impeller will rapidly improve the hydraulic performance, and the improvement of the hydraulic performance will in turn promote the increase of the impeller diameter, which leads to a small range of stable and efficient work of the impeller, and has a negative impact on the efficiency of the pump.

[0006] Furthermore, as the rotational speed increases, the continuous increase of the outer diameter of the impeller is likely to exceed the design working point, resulting in scraping between the impeller and the support and failure of the blood pump. SUMMARY

[0007] In view of the above shortcomings, one object of the present disclosure is to provide a catheter pump and impeller and pump body thereof capable of reducing the change in the outer diameter of the impeller during work rotation.

[0008] Another object of the present disclosure is to provide a catheter pump and impeller and pump body thereof capable of stably maintaining the pump gap.

[0009] To achieve at least one of the above objects, the present application adopts the following technical solutions:

[0010] A kind of impeller for conduit pump, the impeller can be contained in the pump shell of the conduit pump rotates, including hub and the blade being arranged on hub.Blade has top, the root being arranged on hub and between root and top the reverse fold portion.Root extends obliquely in the radial direction along the first circumferential direction to the reverse fold portion, and the reverse fold portion extends obliquely in the radial direction along the second circumferential direction opposite to the first circumferential direction to the top of blade.The first circumferential direction is opposite to the direction of rotation of impeller.

[0011] Preferably, the impeller has a natural unfolded state when not rotating and a working state corresponding to maximum working speed when rotating.The outer diameter of the top (the outer diameter of the impeller) changes less than 0.5 mm, preferably less than 0.3 mm, and further preferably less than 0.1 mm when the impeller switches from the natural unfolded state to the working state.Further, the outer diameter of the top changes less than 0.3 mm, and further preferably less than 0.1 mm when the impeller switches from the minimum working speed to the maximum working speed in the working state.

[0012] Preferably, the blade includes a first portion between the root and the reverse fold portion, and a second portion between the reverse fold portion and the top.The radial length La of the first portion is greater than 0.5 times the radial length of the second portion, and preferably the radial length La of the first portion is greater than the radial length of the second portion.

[0013] Preferably, the blade includes a first portion between the root and the reverse fold portion, and a second portion between the reverse fold portion and the top.The blade has an inward concave leading surface and an outward convex trailing surface, and the maximum thickness of the second portion is greater than 0.7 times the maximum thickness of the first portion, and further, the maximum thickness of the second portion is greater than the maximum thickness of the first portion.The thickness direction is the normal direction of the profile line of the inward concave leading surface or the outward convex trailing surface in the cross section.

[0014] Preferably, the blade includes a first portion between the root and the reverse fold portion, and a second portion between the reverse fold portion and the top.The cross-sectional area of the first portion is greater than 0.5 times, and preferably 0.8 times the cross-sectional area of the second portion.

[0015] Preferably, in a cross section of the blade, the blade includes a first portion between the root and the reverse fold portion, and a second portion between the reverse fold portion and the top.The tangent line of the reverse fold portion passes through the center of the hub;The length of the first portion in the direction perpendicular to the tangent line is greater than 0.3 times, and preferably 0.5 times the length of the second portion in the direction perpendicular to the tangent line.

[0016] Preferably, the blade includes a first portion located between the blade root and the inflected portion, and a second portion located between the inflected portion and the blade tip; the blade has an inward concave flow-facing surface and an outward convex flow-receiving surface facing each other; wherein, at any point on the inward concave flow-facing surface or the outward convex flow-receiving surface of the first portion, the tangent line defining the arbitrary point has a tangent vector away from the second portion. The tangent line of any point has a contact point with the outer contour line of the hub, and the center of the hub is defined as a ray vector pointing to the contact point. Tangent vector and ray vector The included angle β therebetween is greater than 90 degrees and less than 180 degrees.

[0017] Preferably, the closer the point on the concave flow-facing surface or the convex flow-facing surface of the first portion is to the inflection portion, the larger the angle β thereof. Preferably, the blade root has an arc transition portion between the concave flow-facing surface and the hub, and / or the blade root has an arc transition portion between the concave flow-facing surface and the hub.

[0018] An impeller for a duct pump, capable of being accommodated and rotated within the pump casing of the duct pump, comprises a hub and blades disposed on the hub. The blades have a blade tip, a blade root disposed on the hub, and a reflex portion located between the blade root and the blade tip. In a cross section of the blade having a maximum outer diameter, the blade root extends radially and obliquely toward the reflex portion in a first circumferential direction opposite to the direction of impeller rotation; the reflex portion extends radially and obliquely toward the blade tip in a second circumferential direction opposite to the first circumferential direction.

[0019] An impeller for a duct pump, capable of being housed and rotated within a pump casing of the duct pump, comprises a hub and blades disposed on the hub. The blade tips have blade roots disposed on the hub. When the impeller is operating, the outer diameter of the blade tips changes by less than 0.3 mm when switching from a minimum operating speed to a maximum operating speed. Furthermore, the outer diameter of the blade tips changes by less than 0.1 mm.

[0020] A catheter pump body comprises a pump housing with a blood outlet and a blood inlet, and an impeller housed within the pump housing and rotatable to pump blood from the blood inlet to the blood outlet. The pump body has a radially collapsed state suitable for intervention with or delivery within a subject's vascular system, a naturally expanded state corresponding to when the impeller is not rotating, and an operating state corresponding to when the impeller is rotating. During the transition of the pump body from the naturally expanded state to the operating state, the impeller is configured to have an outer diameter change of less than 0.5 mm, preferably less than 0.3 mm, and more preferably less than 0.1 mm.

[0021] Preferably, the impeller is configured such that its outer diameter remains unchanged or increases by less than 0.3 mm.

[0022] Preferably, the pump housing comprises a covering membrane defining the blood flow channel and a support frame supporting the covering membrane; the impeller is accommodated in the support frame; during the switching of the pump body from the natural expansion state to the working state, the support frame is configured not to participate in causing elastic deformation and plastic deformation of the covering membrane, or, in the working state of the pump body, the support frame is configured not to participate in causing elastic deformation and plastic deformation of the covering membrane.

[0023] Preferably, during the switching of the pump body from the natural expansion state to the working state, the increase rate of the outer diameter of the support frame is not more than 1%.

[0024] Preferably, during the switching of the pump body from the natural expansion state to the working state, the deformation of the covering membrane does not exceed the elastic deformation limit thereof, or, in the working state of the pump body, the deformation of the covering membrane does not exceed the elastic deformation limit thereof.

[0025] Preferably, the impeller comprises a hub fixedly sleeved on the impeller shaft and blades provided on the hub; the blades have blade roots provided on the hub and blade tips away from the hub; the pump gap is defined between the blade tips and the inner wall of the support frame; the gap width of the pump gap in the radial direction is less than 1.5 mm.

[0026] Preferably, during the switching of the pump body from the natural expansion state to the working state, the change amount of the gap width of the pump gap in the radial direction is less than 0.5 mm.

[0027] Preferably, the pump body of the catheter pump comprises the impeller of any one of the above.

[0028] A catheter pump comprises a motor, a drive shaft penetrating in a catheter and in transmission connection with the output shaft of the motor, and a pump body capable of pumping blood to a desired position of a heart through the catheter. The pump body comprises the impeller of any one of the above and a pump housing accommodating the impeller, or the pump body of any one of the above; the pump housing of the pump body is connected to the distal end of the catheter, and the impeller is connected to the distal end of the drive shaft.

[0029] By adopting the scheme of the embodiment, the first part inside the reverse folding part of the blade of the impeller of the embodiment is used to balance the radial expansion amount of the second part outside the reverse folding part, the parts with different extension directions inside and outside are arranged by arranging the reverse folding part, the radial diameter change generated during rotation is balanced, the transition change of the outer diameter of the impeller due to the increase of the rotation speed is reduced, the hydraulic performance of the impeller can be kept stable, and the impeller can continuously and stably work efficiently when working in the working speed range.

[0030] The outer diameter change amount of the impeller of the embodiment remains unchanged or is located in a smaller change range in the working speed range, has a better stable outer diameter keeping capability, makes the blood pump keep the stability of working in a wider speed range, matches the performance and the speed, and improves the usability of the blood pump. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a three-dimensional schematic diagram of a catheter pump provided by one embodiment of the present disclosure;

[0032] Figure 2 yes Figure 1 Schematic diagram of the pump casing;

[0033] Figure 3 is a schematic diagram of a pump casing provided by another embodiment of the present disclosure;

[0034] Figure 4 yes Figure 3 The main view;

[0035] Figure 5 yes Figure 4 Schematic diagram of the bracket structure;

[0036] Figure 6 yes Figure 5 The main view;

[0037] Figure 7 yes Figure 6 AA cross-section of

[0038] Figure 8 is a three-dimensional diagram of a bracket provided by another embodiment of the present disclosure;

[0039] Figure 9 yes Figure 8 sectional view of

[0040] Figure 10 yes Figure 1 Partial schematic diagram of

[0041] Figure 11 yes Figure 10 Schematic diagram of the bracket and impeller assembly;

[0042] Figure 12 yes Figure 10 Schematic diagram of impeller assembly;

[0043] Figure 13 yes Figure 12 Schematic diagram of the impeller;

[0044] Figure 14 yes Figure 13 Side view of;

[0045] Figure 15 yes Figure 10 Cross-sectional view of the pump body;

[0046] Figure 16 yes Figure 15 AA cross-section diagram.

[0047] Description of reference numerals:

[0048] 1, power assembly; 2, coupling; 3, conduit; 4, pump body; 5, non-invasive support; 6, distal bearing chamber; 106, blood inlet; 320, proximal bearing chamber; 310, drive shaft; 355, impeller shaft;

[0049] 100, covering; 101, conical section; 102, distal end of covering; 103, cylindrical section; 105, blood outlet;

[0050] 200, stent; 201, stent section; 202, proximal end of conical stent; 203, distal end of conical stent; 204, connecting leg; 2041, stem; 2042, leg end; 205, connecting sub-tube; 210, connecting hole; 211, positioning buckle; 300, anti-expansion element;

[0051] 410, impeller; 411, blade; 412, hub; 418, pressure surface; 419, suction surface; A, first portion; B, second portion; D2, outer inflection point; D3, inner inflection point; 450, trajectory circle; 4111, tip; 4112, root; 4113, constant outer diameter section; 4115, transition line; 4116, transition point; 4121, proximal end of hub; 4122, distal end of hub. DETAILED DESCRIPTION

[0052] In order to make the personnel in the technical field better understand the technical solutions in the present disclosure, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in combination with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative labor should belong to the protection scope of the present disclosure.

[0053] It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or there can be a middle element between them. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there can be a middle element between them. The terms "vertical", "horizontal", "left", "right", and similar expressions used herein are for illustrative purposes only and do not represent the only implementation.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used in the description of the disclosure herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0055] The terms "proximal", "distal" and "anterior", "posterior" are relative to the clinician who manipulates the catheter pump. The terms "proximal", "posterior" refer to the parts relatively close to the clinician, and the terms "distal", "anterior" refer to the parts relatively far from the clinician. For example, the extracorporeal part is proximal and posterior, and the intracorporeal part of the intervention is distal and anterior.

[0056] The catheter pump of the embodiments of the present application is used for assisting heart failure, pumping blood to the heart to achieve partial blood pumping function of the heart. In the scenario suitable for left ventricular assistance, the catheter pump pumps blood from the left ventricle into the aorta to provide support for blood circulation, reduce the workload of the subject's heart, or provide additional continuous pumping power support when the heart's pumping capacity is insufficient.

[0057] Of course, the catheter pump can also be inserted into other target positions of the subject, such as the right ventricle, blood vessels, or other organs, according to the intervention of the interventional surgery.

[0058] Please refer to Figure 1 、 Figure 2 The catheter pump of the embodiments of the present disclosure includes a power assembly 1 and a working assembly. The power assembly 1 includes a housing and a motor received in the housing and having an output shaft, and the working assembly includes a catheter 3, a drive shaft 310 arranged in the catheter 3, and a pump body 4.

[0059] The pump body 4 can be delivered through the catheter 3 to the desired position of the heart, such as the left ventricle, to pump blood, including a pump shell having a blood inlet 106 and a blood outlet 105, and an impeller 410 received in the pump shell. The motor is arranged at the proximal end of the catheter 3, connected to the catheter 3 through the coupler 2, and drives the impeller 410 to rotate and pump blood through the drive shaft 310. The pump shell of the pump body 4 is connected to the distal end of the catheter 3, and the impeller 410 is connected to the distal end of the drive shaft 310.

[0060] The pump shell includes a covering film 100 defining a blood flow channel, and further includes a stent 200 for supporting the expansion of the covering film 100, and the proximal end of the stent 200 is connected to the distal end of the catheter 3. The proximal end of the stent 200 is provided with a connecting secondary tube 205, and a connecting hole 210 constituting a female buckle is arranged on the connecting secondary tube 205, forming a buckle type mechanical connection structure with the catheter 3.

[0061] The blade 411 is made of a flexible elastic material, which stores energy when being folded, and releases the stored energy to unfold the blade 411 when the external constraint is removed. The plurality of blades 411 are evenly arranged in the circumferential direction.

[0062] As shown in Figures 12-14 , the blade 411 is arranged closer to the distal end 4122 on the hub 412. The blade 411 has an outer diameter constant section 4113. The blade 411 has a leading edge (first water entry edge) and a trailing edge (second water entry edge) at the two axial ends thereof. The outer diameter constant section 4113 is located between the leading edge and the trailing edge and extends in a curve therebetween. The outer diameter of the outer diameter constant section 4113 is the maximum outer diameter of the blade 411. The outer diameter constant section 4113 and the leading edge and the trailing edge have transition sections 4116 therebetween, which can be rounded structures. The outer diameter constant section 4113 has a length of more than 0.5 times, or even more than 0.8 times the length of the blade 411. The outer diameter constant section has transition lines 4115 at the two ends thereof. The blade tip 4111 has a blade tip edge extending in a curve in the axial direction. The blade tip edge extends between the leading edge (first water entry edge) and the trailing edge (second water entry edge). The blade tip 4111 (blade tip end) forms a circular trajectory (trajectory circle 450) when the blade 411 rotates. The outer diameter of the impeller 410, the outer diameter of the blade tip 4111, or the diameter on which the blade tip 4111 is located is the diameter of the circular trajectory.

[0063] As shown in Figures 10-16 , the impeller 410 can be accommodated in the pump housing of a conduit pump and rotate therein. The impeller 410 includes a hub 412 and a plurality of blades 411 arranged on the hub 412. The blade 411 has a blade root 4112 arranged on the hub 412, a blade tip 4111 away from the hub 412, and a reverse fold D2D3 between the blade root 4112 and the blade tip 4111 (blade tip end). The blade root 4112 of the blade 411 extends in a first circumferential direction in the radial direction and inclines towards the reverse fold D2D3. The reverse fold D2D3 extends in a second circumferential direction opposite to the first circumferential direction in the radial direction and inclines towards the blade tip 4111 of the blade 411. The first circumferential direction is opposite to the rotation direction of the impeller 410. The second circumferential direction is the same as (parallel to) the rotation direction of the impeller 410.

[0064] As shown in Figure 16 , the blade 411 has an inner concave flow face 418 and an outer convex back flow face 419 opposite to each other. The flow face 418 of the blade 411 is concave, and the back flow face 419 is convex. The blade 411 has at least one cross section (cross section perpendicular to the axial direction), which is a C-shaped structure. In the cross section, the blade root 4112 of the blade 411 extends in a first circumferential direction in the radial direction and inclines towards the reverse fold D2D3. The reverse fold D2D3 extends in a second circumferential direction opposite to the first circumferential direction in the radial direction and inclines towards the blade tip 4111 of the blade 411.

[0065] At the cross section where the blade 411 has the maximum outer diameter. The cross section is taken from the outer diameter constant section 4113. Preferably, any cross section of the outer diameter constant section 4113 has a reverse fold D2D3, which forms corresponding reverse fold position points D2, D3 on the inner and outer surfaces (inner and outer profiles). The reverse fold D2D3 forms a continuous outer reverse fold line composed of the outer reverse fold position point D2 at the back flow surface 419, and forms a continuous inner reverse fold line composed of the inner reverse fold position point D3 at the front flow surface 418. The blade root 4112 of the blade 411 extends radially and in a first circumferential direction towards the reverse fold D2D3. The reverse fold D2D3 extends radially and in a second circumferential direction opposite to the first circumferential direction towards the blade tip 4111 of the blade 411.

[0066] The blade 411 includes a first portion A between the blade root 4112 and the reverse fold D2D3, and a second portion B between the reverse fold D2D3 and the blade tip 4111. The first portion A and the second portion B extend radially as a whole, and extend in opposite circumferential directions.

[0067] The inventor has found that, when the impeller 410 rotates, the first portion A and the second portion B are respectively subjected to a rotating centrifugal force, a reaction force from the fluid acting on the blade 411, fluid back pressure, and other forces. Under the combined action of the multiple forces (combined forces), the first portion A and the second portion B extend in opposite circumferential directions, and thus have different effects. The second portion B on the radially outer side of the first portion A expands to some extent in the radial direction under the combined action, so that the impeller 410 has a tendency to increase in diameter. The first portion A on the radially inner side of the second portion B contracts to some extent in the radial direction under the combined action, so that the blade 411 has a tendency to decrease in diameter.

[0068] Among them, the reaction force (resistance) from the fluid acting on the blade 411 is the main force. The first circumferential direction in which the first portion A extends is substantially parallel to the direction of the reaction force. When the reaction force acts on the first portion A, it presses the first portion A downward towards the hub 412, promoting the movement of the first portion A towards the hub 412, and forming a contraction trend. The second circumferential direction in which the second portion B extends is substantially opposite to the direction of the reaction force. When the reaction force acts on the second portion B, it pushes the second portion B outward, promoting the radial expansion of the second portion B, and forming an expansion trend.

[0069] Therefore, the blade 411 of the impeller 410 in the embodiment balances the radial expansion of the second part B outside the reverse fold D2D3 by the first part A inside the reverse fold D2D3, balances the radial diameter change generated during rotation by setting the parts with different extension directions inside and outside the reverse fold D2D3, reduces the transition change of the outer diameter of the impeller 410 due to the increase of the rotation speed, and can keep the hydraulic performance of the impeller 410 stable, so that the impeller 410 can work stably and efficiently in a stable and efficient manner in the working speed range.

[0070] The impeller 410 has a better ability to keep the outer diameter stable, and can keep the stability of the blood pump in a wider speed range, the performance and the linear matching of the speed, and improve the usability of the blood pump.

[0071] In the embodiment, the outer diameter of the impeller 410 changes little during rotation, and the conduit pump can keep the pump gap stable during work. Specifically, the pump gap is defined between the blade top 4111 and the inner wall of the bracket 200. The gap width of the pump gap in the radial direction is less than 1.5 mm.

[0072] The impeller 410 has a natural unfolded state when not rotating and a working state when rotating at a maximum working speed. When the impeller 410 switches from the natural unfolded state to the working state, the diameter change of the blade top 4111 is less than 0.5 mm, that is, the outer diameter change of the impeller 410 is within ±0.5 mm (the outer diameter increase is within 0.5 mm, and the outer diameter decrease is within 0.5 mm). Preferably, the outer diameter change of the impeller 410 is less than 0.3 mm (within ±0.3 mm), and more preferably, the outer diameter change of the impeller 410 is less than 0.1 mm (within ±0.1 mm).

[0073] It is worth noting that the above numerical values include all values from the lower limit value to the upper limit value with an increment of one unit, and there is at least a two-unit interval between any lower value and any higher value.

[0074] For example, the outer diameter change of the impeller 410 is within ±0.5 mm, preferably within ±0.3 mm, and more preferably within ±0.1 mm, which is to illustrate the above-mentioned values such as +0.08, -0.05, and ±0.03, which are not explicitly listed.

[0075] As mentioned above, the example ranges with intervals of 0.1 do not exclude increases in intervals of appropriate units such as 0.01, 0.02, 0.03, 0.04, 0.05, etc. These are merely examples intended to be express, and it is considered that all possible combinations of numerical values ​​between the lowest value and the highest value are expressly stated in this specification in a similar manner.

[0076] Unless otherwise indicated, all ranges include the endpoints and all numbers between the endpoints. When used with a range, "about" or "approximately" applies to both endpoints of the range. Thus, "about 20 to 30" is intended to cover "about 20 to about 30," including at least the specified endpoints.

[0077] For other limitations on the numerical range appearing in this article, please refer to the above description and will not be repeated here.

[0078] like Figure 16 As shown, the radial (projected) length La of the first portion A is greater than 0.5 times the radial (projected) length Lb of the second portion B. In other words, the radial length La of the first portion A is greater than 0.5 times the radial length of the second portion B, La>0.5Lb. Preferably, the radial (projected) length La of the first portion A is greater than the radial (projected) length Lb of the second portion B.

[0079] In some embodiments, the thickness of the blade 411 of the first part A is greater than the thickness of the blade 411 of the second part B. The first part A has a more stable structure than the second part B, thereby improving the structural strength of the blade 411 to ensure fluid pumping efficiency. In this embodiment, the maximum thickness of the second part B is greater than 0.7 times the maximum thickness of the first part A. The thickness direction is the normal direction of the contour line of the concave frontal surface 418 or the convex backflow surface 419 on the cross section. Furthermore, the maximum thickness of the second part B is greater than the maximum thickness of the first part A. In this way, by increasing the thickness of the second part B, the deformation resistance of the second part B is improved, the degree of outward expansion is avoided, and the outer diameter of the impeller 410 is stably maintained.

[0080] To balance the radial variation of the first portion A and the second portion B and maintain the outer diameter of the impeller 410, the cross-sectional area of ​​the first portion A is at least 0.5 times the cross-sectional area of ​​the second portion B. Preferably, the cross-sectional area of ​​the first portion A is at least 0.8 times the cross-sectional area of ​​the second portion B. The cross-sectional area of ​​the first portion A is no more than 1.2 times the cross-sectional area of ​​the second portion B. By increasing the first portion A and decreasing the second portion B, the proportions of the first portion A and the second portion B are balanced, thereby balancing the radial variation of the first portion A and the second portion B.

[0081] Furthermore, if Figure 16As shown, in a cross section of the blade 411, the tangent of the inflected portion D2D3 passes through the center O of the hub 412. The length H1 of the first portion A in the direction perpendicular to the tangent OO2 is greater than or equal to 0.3 times the length H2 of the second portion B in the direction perpendicular to the tangent OO2. Preferably, H1 is greater than or equal to 0.5 times H2.

[0082] On a cross-section of impeller 410, the outward convex backflow surface 419 has a point D2. A tangent line OO2 at this point passes through the center O of hub 412, with the cross-section of blade 411 located circumferentially to one side of this tangent line OO2. Alternatively, a straight line passing through this point and the center of hub 412 is defined, with the cross-section of blade 411 (the entirety) located circumferentially to one side of this straight line. Point D2 is located between blade root 4112 and blade tip 4111 and is the outer inflection point D2 formed by inflection D2D3 on the cross-section profile.

[0083] like Figure 16 As shown, at any point on the concave oncoming surface 418 or the convex oncoming surface 418 of the first portion A, the tangent line defining the arbitrary point has a tangent vector away from the second portion B. The tangent line of the arbitrary point has a contact point with the outer contour line of the hub 412, and the center of the hub 412 is defined as having a ray vector toward the contact point. Tangent vector and ray vector The included angle β therebetween is greater than 90 degrees and less than 180 degrees. The closer the position point on the concave oncoming surface 418 or the convex oncoming surface 418 of the first portion A is to the inflected portion D2D3, the larger the angle β is.

[0084] The blade root 4112 has an arc transition portion between the inner concave flow-onward surface 418 and the hub 412, and / or the blade root 4112 has an arc transition portion between the outer concave flow-onward surface 418 and the hub 412. The curvature radius of the arc transition portion is smaller than the curvature radius of the first portion A.

[0085] Continuing from the above description, the impeller 410 is operable to rotate within the pump housing to pump blood from the blood inlet 106 to the blood outlet 105. The pump body 4 has a radially collapsed state suitable for intervention in or delivery within a subject's vascular system, a naturally expanded state corresponding to when the impeller 410 is not rotating, and an operating state corresponding to when the impeller 410 is rotating.

[0086] In the process of switching the pump body 4 from the natural expanded state to the working state, the impeller 410 is configured to have a change in the outer diameter of less than 0.5 mm. That is, the change in the outer diameter of the impeller 410 is within a range of ±0.5 mm. Preferably, the impeller 410 is configured to have a change in the outer diameter of less than 0.3 mm, and more preferably, the impeller 410 is configured to have a change in the outer diameter of less than 0.1 mm. The impeller 410 is configured to have an unchanged or increased outer diameter of less than 0.3 mm.

[0087] Further, the working state of the impeller 410 can be a working state at the maximum working rotational speed (maximum rotational speed). Thus, in the process of switching the pump body 4 from the natural expanded state (the impeller 410 is static) to the maximum rotational speed working state, the impeller 410 is configured to have a change in the outer diameter of less than 0.5 mm.

[0088] In the present embodiment, the pump housing has a small change in the inner diameter during the working rotation of the impeller 410, and the impeller 410 is configured to have an increased outer diameter of not more than 1% in the process of switching the pump body 4 from the natural expanded state to the working state. Specifically, the deformation of the covering membrane 100 is not more than the elastic deformation limit of the covering membrane 100 in the process of switching the pump body 4 from the natural expanded state to the working state, or the deformation of the covering membrane 100 is not more than the elastic deformation limit of the covering membrane 100 in the working state of the pump body 4.

[0089] As described above, the pump housing includes the covering membrane 100 defining the blood flow channel and the stent 200 for supporting the expanded covering membrane 100. The tip gap is located between the tip 4111 of the impeller 410 and the inner wall of the foldable stent 200. In other embodiments, the covering membrane 100 is integrated with the stent 200, for example, the covering membrane 100 is integrated with a helical support body, and the tip gap (pump gap) is located between the inner wall of the covering membrane 100 and the tip 4111.

[0090] In the process of switching the pump body 4 from the natural expanded state to the working state, the pump gap has a change in the gap width H3 in the radial direction of less than 0.5 mm, and further less than 0.3 mm. Specifically, the impeller 410 has an increased outer diameter of not more than 0.3 mm in the process of rotating from static to the maximum working rotational speed. The impeller 410 has a change in the outer diameter of within 0.3 mm in the working rotational speed range (for example, 10000-30000 rpm). The impeller 410 has a change in the outer diameter of within 0.3 mm, and further within 0.1 mm, in the process of rotating from the minimum working rotational speed (10000 rpm) to the maximum working rotational speed (30000 rpm), so as to stabilize the pump gap.

[0091] In this embodiment, the bracket 200 can be disposed inside the membrane 100 or outside the membrane 100. The impeller is housed in the bracket 200 and is located inside the membrane 100. The bracket 200 is supported at the distal end 102 of the membrane 100, with part of the bracket 200 located outside the distal end 102 of the membrane 100 and the other part of the bracket 200 located inside the membrane 100.

[0092] When the stent 200 applies an expansion force to the membrane 100, the membrane 100 does not undergo elastic or plastic deformation, and thus exhibits excellent deformation resistance. This allows the membrane 100 to better maintain its shape during blood pumping, and in conjunction with the impeller's stable shape, this maintains a constant pump clearance and optimal pump efficiency.

[0093] The membrane 100 comprises a cylindrical section 103 as its main structure and a tapered section 101 located proximal to the cylindrical section 103. The proximal end of the tapered section 101 is sleeved over the catheter 3 and secured to its outer wall. The catheter 3 is connected to the proximal end of the bracket 200 via a proximal bearing chamber at its distal end. This chamber houses a proximal bearing that rotatably supports the drive shaft 310. In one embodiment, the connecting secondary tube 205 directly forms the proximal bearing chamber, and the proximal bearing is positioned and secured by a retaining clip 211.

[0094] The distal end of the bracket 200 is provided with a distal bearing chamber 6, and the distal bearing chamber 6 is provided with a distal bearing for supporting the distal rotation of the drive shaft 310. The bracket 200 maintains the distance between the proximal bearing chamber 320 and the distal bearing chamber 6, thereby providing a space for the drive shaft 310 to rotate.

[0095] Providing stable rotational support. The drive shaft 310 comprises a flexible shaft inserted into the conduit 3 and a rigid shaft 355 (impeller shaft 355) connected to the distal end of the flexible shaft. The hub 412 of the impeller 410 is sleeved on the rigid shaft 355. The proximal and distal ends of the rigid shaft 355 are respectively inserted into the proximal and distal bearings. The rigid shaft 355 and the bearings at both ends provide stable support for the impeller in the pump casing, maintaining its position within the pump casing.

[0096] Coupler 2 connects to the proximal end of catheter 3. A fluid channel exists between catheter 3 and the flexible shaft. Irrigation fluid supplied through the channel lubricates the flexible shaft's rotation and prevents frictional heat generation. Coupler 2 is equipped with an irrigant inlet 20, which communicates with the channel. A retaining sleeve 260, through which catheter 3 passes, is located at the distal end of coupler 2. Retaining sleeve 260 secures catheter 3.

[0097] The distal end of the distal bearing chamber 6 is connected to a non-invasive support member 5, which is a flexible tubular structure, and the performance 5 is a flexible protrusion with an arc shape or a coiled shape at the end, so that the non-invasive support member 5 supports the distal end of the distal bearing chamber 6 in a non-invasive or non-destructive manner.

[0098] On the inner wall of the ventricle, the blood inlet 106 of the pump body 4 is separated from the inner wall of the ventricle to prevent the suction port of the pump body 4 from sticking to the inner wall of the ventricle due to the reaction force of the blood during the operation of the pump body 4, thereby ensuring the effective pumping area.

[0099] The pump housing includes a radially collapsed portion adapted for insertion into or delivery within the vasculature of a subject.

[0100] In the process of switching the pump casing from the radially folded state to the naturally expanded state, or from the naturally expanded state to the working state,

[0101] The deformation of the coating 100 does not exceed its plastic deformation limit.

[0102] As described above, the pump housing includes a membrane 100 that defines a blood flow channel and a support 200 that supports the expanded membrane 100. The impeller 410 is housed in the support 200. When the pump body 4 switches from the natural expanded state to the working state, the impeller 410 is rotated.

[0103] During the process, the bracket 200 is configured not to participate in causing elastic deformation and plastic deformation of the coating. Alternatively, when the pump body 4 is in operation, the bracket 200 is configured not to participate in causing elastic deformation and plastic deformation of the coating 100.

[0104] The pump body 4 has an interventional configuration and a working configuration. In the interventional configuration, the pump housing and impeller are in a radially collapsed state, allowing the pump body 4 to intervene in or deliver blood within the subject's vascular system at a first outer diameter. In the working configuration, the pump housing and impeller are in a radially expanded state, allowing the pump body 4 to pump blood at a desired location at a second outer diameter greater than the first outer diameter.

[0105] The pump body 4 has a radially collapsed state and a radially expanded state, and the pump housing is operable to switch between the radially collapsed state and the radially expanded state. Compared to the unstressed state, the coating 100 does not undergo plastic deformation when the pump housing is in the radially expanded state.

[0106] By providing a foldable pump housing, the pump housing has a smaller folded size and a larger unfolded size, so as to meet the two requirements of alleviating the pain of the subject and facilitating the intervention during the intervention / delivery process, as well as providing a large flow rate.

[0107] The multi-mesh design of stent 200, particularly the diamond-shaped mesh, allows for optimal folding while also enabling expansion thanks to the memory properties of nickel-titanium alloy. The blades, made of a flexible and elastic material, store energy when folded. Once the external constraints are removed, the stored energy is released, allowing the blades to expand.

[0108] The pump housing collapses with the aid of external constraints. Once these constraints are removed, the pump housing automatically expands. This external constraint is achieved via a folding sheath (not shown) that slides over the catheter 3. As the folding sheath moves forward outside the catheter 3, it retracts the entire pump housing, forcing it to collapse. When the folding sheath moves backward, the radial constraints on the pump housing are removed, allowing the pump housing to expand automatically.

[0109] As mentioned above, the pump casing collapses thanks to the radial restraint exerted by the folding sheath, while the impeller contained within the pump casing is housed within the pump casing. Therefore, in essence, the collapse of the pump casing occurs as follows: the folding sheath exerts radial restraint on the pump casing, which, when radially compressed, exerts radial restraint on the impeller.

[0110] In other words, the pump casing is directly folded by the folding sheath, while the impeller is directly folded by the pump casing. As mentioned above, the impeller is elastic. Therefore, even in the folded state, the impeller's folded energy stores a tendency to expand radially, causing the impeller to contact the inner wall of the pump casing and exert a reaction force on the pump casing.

[0111] After the restraint of the folding sheath is removed, the pump housing, under the effect of its own memory property, supports the elastic covering 100 to unfold, and the impeller automatically unfolds under the effect of the released stored energy. In the unfolded state, the outer diameter of the impeller is smaller than the inner diameter of the pump housing.

[0112] In this way, a distance is maintained between the radial outer end of the impeller (i.e., the blade tip) and the inner wall of the pump housing (specifically, the inner wall of the bracket 200), which is the pump clearance. The existence of the pump clearance allows the impeller to rotate unimpeded without hitting the wall.

[0113] Furthermore, for fluid dynamics reasons, it is desirable to maintain a small pump clearance. In this embodiment, the outer diameter of the impeller is slightly smaller than the inner diameter of the support 200, which serves as the support. This minimizes the pump clearance while ensuring that the impeller rotates without hitting the wall. The primary means of maintaining the pump clearance is through the support strength provided by the support 200 and the anti-extension deformation performance of the coating 100. This support strength and the toughness of the coating 100 can resist the effects of blood back pressure without excessive deformation, thereby maintaining the shape of the pump housing and thus the pump clearance.

[0114] To ensure the toughness of membrane 100, provide a more stable pump clearance, and stabilize pump efficiency, the critical stress at which membrane 100 experiences plastic deformation is equal to or greater than the force exerted on membrane 100 by the blood backpressure caused by impeller rotation when the pump is operating at maximum capacity. The maximum operating condition of the pump corresponds to the maximum speed of the impeller at rated power. At this point, the pump flow rate reaches its maximum, and the blood backpressure is also at its maximum.

[0115] In this embodiment, the maximum value of the blood back pressure still does not exceed the critical point stress of the plastic deformation limit of the membrane 100. Therefore, when the impeller rotates, the membrane 100 will still not exceed the plastic deformation limit, thereby reducing the change in the pump gap and stabilizing the pump efficiency.

[0116] Furthermore, during the switching of the pump housing from the radially collapsed state to the naturally expanded state, the deformation of the membrane 100 does not exceed its elastic deformation limit. During the switching of the pump housing from the naturally expanded state to the working state, the deformation of the membrane 100 does not exceed its elastic deformation limit.

[0117] The critical stress at which the membrane 100 experiences elastic deformation is greater than or equal to the force exerted on the membrane 100 by the blood back pressure caused by the rotation of the impeller when the pump body 4 is at maximum operating conditions. This allows the membrane 100 to elastically return to its original state when the impeller stops rotating or the fluid back pressure disappears, ensuring stable pump efficiency and a longer service life.

[0118] It should be noted that the deformation of the coating 100 in the present invention refers to the deformation of the coating 100 in the circumferential direction. This deformation may include the flattening of wrinkles, elastic deformation, or even plastic deformation. When subjected to radial force, the deformation of the coating 100 is manifested as an increase in the circumferential length (circumference).

[0119] During the transition from the naturally expanded state to the operating state, the diameter of the membrane 100 increases by no more than 1 mm, with a diameter increase rate of no more than 5%, and further, no more than 3%. Thus, the membrane 100's expansion deformation under fluid back pressure does not exceed its plastic deformation limit, and it cooperates with the impeller 410 to maintain a stable pump clearance.

[0120] During the transition of the pump housing from its naturally deployed state to its operational state, the bracket is configured to not participate in causing deformation of the membrane 100. Alternatively, when the pump housing is in the operational state, the bracket is configured to not participate in causing deformation of the membrane 100. This deformation includes both elastic and plastic deformation. In other words, during the transition of the pump housing from its naturally deployed state to its operational state, the bracket neither participates in causing plastic nor elastic deformation of the membrane 100.

[0121] In the naturally expanded state, the inner diameter of the coating 100 is equal to or slightly larger than the outer diameter of the stent. For example, the diameter of the coating 100 is 1 to 1.1 times the outer diameter of the stent. In this way, during the entire process from the folded state to the expanded state, the coating 100 expanded by the radial expansion of the stent does not reach or exceed its original shape (original diameter). Therefore, the stent does not cause circumferential stretching of the coating 100. It can be understood that the coating 100 does not undergo elastic deformation or plastic deformation in the naturally expanded state, and the stent is configured not to participate in causing the deformation of the coating 100.

[0122] In this embodiment, the membrane 100 is made of TPU (thermoplastic polyurethane elastomer), PEBAX, or PTFE (polytetrafluoroethylene). Preferably, the membrane 100 is a segmented polyetheramide resin material such as PEBAX. The membrane 100 exhibits no loss of mechanical properties under repeated deformation, is fatigue-resistant, and possesses excellent rebound and elastic recovery properties, as well as precise dimensional stability. Furthermore, deformation under fluid backpressure does not exceed the plastic or elastic deformation limits, thereby maintaining a stable pump clearance.

[0123] The distal end of the bracket 200 is formed with a plurality of legs 204 having a roughly T-shaped structure, and the legs 204 have rods 2041 and leg ends 2042 that are roughly perpendicular to the pump housing. The outer wall of the distal bearing chamber 6 is provided with a receiving groove, which includes a plurality of axial grooves extending roughly axially and a circumferential groove connected to the distal ends of the plurality of axial grooves. The plurality of rods 2041 are respectively embedded in the corresponding axial grooves, and the plurality of leg ends 2042 are embedded in the circumferential grooves. A hoop is also provided on the outside of the distal bearing chamber 6 to tightly wrap and fix the legs 204 to prevent them from popping out of the receiving groove. The hoop can be formed by heating a heat shrink tube to bind the connecting legs 204 to the outer wall of the distal bearing chamber 6, thereby preventing the two from falling off and fixing them.

[0124] The stent 200 has a support portion that contacts and supports the membrane 100. In the naturally deployed state, at least a portion of the support portion contacts the membrane 100. In the operating state, at least a portion of the support portion is separated from the membrane 100.

[0125] Specifically, when the impeller rotates and drives blood flow, the membrane 100, under the action of fluid back pressure, flattens some of its wrinkles or undergoes elastic or plastic deformation, increasing its inner diameter until it separates from the support portion. The membrane's inherent toughness limits the rate of deformation. Even if elastic or plastic deformation causes circumferential elongation of the membrane 100, the change in elongation is less than 3%. Consequently, the gap between the impeller and the membrane 100 is maintained during operation, ensuring consistent and stable pump efficiency.

[0126] Stent 200 comprises a roughly conical proximal end 202 and a distal end 203, as well as a roughly cylindrical stent segment 201 located between the proximal and distal ends 202 and 203. At least a portion of the axial length of stent segment 201 constitutes the support portion. The distal end of membrane 100 is sheathed over stent segment 201, supported by stent segment 201 to form a stable cylindrical pump housing. The distal end surface of membrane 100 does not extend beyond stent segment 201.

[0127] During the transformation of the pump housing from the radially collapsed state to the radially expanded state, the support portion and the membrane 100 are allowed to move relative to each other, and the contact position of the membrane 100 with the support portion such as the stent segment 201 is allowed to change. The relative position of the stent 200 and the membrane 100 is fixed and does not change.

[0128] The support portion and the stent 100 are merely contact supports, with no fixed connection. Consequently, during deployment of the stent 100, the support portion and the stent 100 experience a certain degree of relative motion, thereby achieving the desired deployment. Furthermore, the support portion provides circumferential support to the stent 100 without constraining radial or circumferential relative motion. This allows the stent 100 to move radially or circumferentially relative to the support portion, causing the contact area of ​​the stent 100 with the support portion or stent to change during deployment.

[0129] When the impeller rotates to drive the blood flow, the diameter of the membrane 100 increases mainly due to the back pressure of the blood, causing the membrane 100 to separate from the stent 200 and not contact each other. The stent 200 loses its support for the membrane 100 and does not participate in the deformation of the membrane 100 at this time.

[0130] During the transition of the pump housing from its naturally deployed state to its operational state, the radial increase of the stent 200 is less than the radial increase of the membrane 100. Specifically, the rate of increase in the outer diameter of the stent 200 is less than the rate of increase in the inner diameter of the membrane 100, or the increase in the outer diameter of the stent 200 is less than the increase in the inner diameter of the membrane 100. During the transition of the pump housing from its naturally deployed state to its operational state, the rate of increase in the outer diameter of the stent 200 does not exceed 2%. Furthermore, during the transition of the pump housing from its naturally deployed state to its operational state, the rate of increase in the outer diameter of the stent 200 does not exceed 1%.

[0131] In such Figures 3 to 9 In the illustrated embodiment, to prevent the stent from contributing to elastic or plastic deformation of the membrane 100 and to limit the deformation of the stent 200 within the impeller's operating speed range, the pump casing is further provided with an anti-extension element 300 for limiting radial expansion of the stent 200. In operation, the outer diameter of the stent 200 with the anti-extension element 300 is smaller than that without the anti-extension element 300.

[0132] In this embodiment, the naturally expanded state of stent 200 is limited by anti-extension element 300. That is, radial expansion of stent 200 causes stretching of anti-extension element 300. However, once anti-extension element 300 is stretched to a certain extent, the stent cannot expand further and reaches its maximum diameter.

[0133] Fluid back pressure affects the radial expansion of anti-extension element 300 and stent 200, but the extent of their radial expansion is limited, and their expansion is lower than that of coating 100. In operation, anti-extension element 300 limits the radial expansion of at least a portion of the strut, separating it from coating 100. With anti-extension element 300, the radial expansion of stent 200 is limited by anti-extension element 300 to a value lower than that of coating 100.

[0134] The diameter of the anti-extension element 300 is smaller than the diameter of the coating 100. The anti-extension element 300 can be disposed inside or outside the stent. The anti-extension element 300 is disposed within the coating 100 around the stent 200. Specifically, the anti-extension element 300 is disposed around the stent segment 201.

[0135] The anti-extension element 300 includes a hoop fixedly sleeved on the outside of the stent segment 201. The hoop can be welded or clamped to the outside of the stent segment 201. Figures 3 to 7 In the embodiment shown, a plurality of hoop rings are discretely arranged outside the stent segment 201. Figure 8 、 Figure 9 In the illustrated embodiment, a single hoop (hoop) is centrally positioned over the stent segment 201. The hoop is made of metal or other anti-expansion material, and its circumferential expansion and deformation resistance is greater than that of the stent, and even greater than that of the graft 100. Consequently, in operation, the anti-expansion element 300 acts to minimize the radial expansion rate of the stent, thereby separating the stent from the further radially expanded graft 100, preventing contact between the two.

[0136] It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the appended claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein from the foregoing claims is not intended to be a disclaimer of such subject matter, nor should it be assumed that the inventors did not consider such subject matter to be part of the disclosed inventive subject matter.

Claims

1. An impeller for a catheter pump, the impeller being capable of being housed within a pump casing of the catheter pump, comprising a hub and blades disposed on the hub; the blades having a blade tip, a blade root disposed on the hub, and a reflex portion located between the blade root and the blade tip; the blades being made of a flexible and elastic material; The impeller has a naturally expanded state when not rotating; in the naturally expanded state, on the cross section of the blade having the maximum outer diameter, the blade root extends obliquely along a first circumferential direction in the radial direction toward the inflected portion; the inflected portion extends obliquely along a second circumferential direction in the radial direction opposite to the first circumferential direction toward the blade top.

2. The impeller according to claim 1, wherein: When the impeller switches from a minimum operating speed to a maximum operating speed in a working state, a change in the outer diameter of the impeller tip is less than 0.3 mm.

3. The impeller according to claim 2, wherein: The outer diameter variation of the blade tip is less than 0.1 mm.

4. The impeller according to claim 1, wherein: The blades are arranged on the hub closer to the distal end of the hub.

5. The impeller according to claim 1, wherein: The blade has a leading edge and a trailing edge at both ends of the axial direction, and an outer diameter constant section is located between the leading edge and the trailing edge; the outer diameter of the outer diameter constant section extends in a curve between the leading edge and the trailing edge; the outer diameter of the outer diameter constant section is the maximum outer diameter of the blade.

6. The impeller according to claim 5, wherein: There are transition portions between the outer diameter constant section and the leading edge and the trailing edge respectively; the transition portions are rounded structures.

7. The impeller according to claim 1, wherein: The constant outer diameter section is more than 0.5 times the extension length of the blade.

8. The impeller according to claim 1, wherein: The constant outer diameter section is greater than 0.8 times the extension length of the blade.

9. The impeller according to claim 1, wherein: The blade includes a first portion located between the blade root and the inflected portion, and a second portion located between the inflected portion and the blade tip; a radial length of the first portion is greater than 0.5 times a radial length of the second portion.

10. The impeller according to claim 9, wherein: The radial length of the first portion is greater than the radial length of the second portion.

11. The impeller according to claim 9, wherein: The cross-sectional area of ​​the first portion is greater than or equal to 0.5 times the cross-sectional area of ​​the second portion.

12. The impeller according to claim 9, wherein: A cross-sectional area of ​​the first portion is greater than or equal to 0.8 times a cross-sectional area of ​​the second portion.

13. The impeller according to claim 9, wherein: The maximum thickness of the second part is greater than 0.7 times the maximum thickness of the first part, wherein the blade has an inner concave flow-facing surface and an outer convex flow-receiving surface facing each other; the thickness direction is the normal direction of the contour line of the inner concave flow-facing surface or the outer convex flow-receiving surface in the cross section.

14. The impeller according to claim 13, wherein: The maximum thickness of the second portion is greater than the maximum thickness of the first portion.

15. The impeller of claim 1, wherein: In a cross section of the blade, the tangent of the inflected portion passes through the center of the hub; the blade includes a first portion located between the blade root and the inflected portion, and a second portion located between the inflected portion and the blade tip; the length of the first portion in a direction perpendicular to the tangent is more than 0.3 times the length of the second portion in the direction perpendicular to the tangent.

16. The impeller according to claim 15, wherein: The length of the first portion in a direction perpendicular to the tangential line is greater than or equal to 0.5 times the length of the second portion in a direction perpendicular to the tangential line.

17. The impeller of claim 1, wherein: The blade includes a first portion located between the blade root and the inflected portion, and a second portion located between the inflected portion and the blade tip; the blade has an inner concave flow-facing surface and an outer convex flow-receiving surface facing each other. Wherein, at any point on the concave oncoming surface or the convex oncoming surface of the first part, the tangent line defining the arbitrary point has a tangent vector away from the second part. The tangent line of any point has a contact point with the outer contour line of the hub, and the center of the hub is defined as having a ray vector toward the contact point. ; The tangent vector and the ray vector The included angle β therebetween is greater than 90 degrees and less than 180 degrees.

18. A catheter pump and a pump body thereof, comprising: An impeller as claimed in any one of claims 1 to 17.

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