Catheter pump

Abstract

This application discloses a catheter pump comprising a catheter, a proximal connector, and a pump head. The proximal connector is connected to the distal end of the catheter, and the pump head comprises a stand and an impeller housed within the stand, the impeller being rotationally driven to pump blood. The stand comprises a stand body and proximal connecting legs located at the axial proximal end of the stand body, the number of proximal connecting legs being multiple, and the multiple proximal connecting legs being spaced apart along the circumferential direction of the stand. The proximal connecting legs comprises a proximal connecting rod and a proximal support rod located at the distal end of the proximal connecting rod. The proximal support rod connects to and supports the stand body, and the circumferential width of the proximal support rod is greater than the circumferential width of the proximal connecting rod. The proximal connecting rod is fixedly connected to the proximal connector. The proximal end support rod includes a first connecting portion fixedly connected to the proximal end connection and a first outer portion located outside the distal end of the proximal end connection.

Description

Technical Field

[0006] ,

[0001] (Cross - reference to related applications) This application claims the priority of a patent application filed with the China National Intellectual Property Administration on April 26, 2023, with an application number of 202310459662.4 and an application title of "Catheter Pump".

[0002] This disclosure relates to the field of medical devices, particularly to catheter pumps.

Background Art

[0003] Catheter pumps include non - foldable and foldable ones. Here, foldable catheter pumps have the advantage that during intervention, the wound area is smaller, so they are more convenient and quickly used.

[0004] Since it is necessary to pre - fold to reduce the size of the pump head and then expand and release it after being inserted into a specific position (such as the left ventricle), it is necessary to use a corresponding structure to form the pump housing part. Considering making the process as simple as possible, a single pre - cast pipe is carved or laser - cut to make the stand part of the pump housing, and a connection ring sleeve for realizing the connection and fixation with the catheter is provided at the proximal end of the stand. Thereby, the diameter of the bush - shaped connection ring sleeve part is the same as the diameter of the pipe pre - cast to form the stand part.

[0005] Since it is necessary to finally meet the requirement of a small size for easy placement and intervention, the diameter of the pre - cast pipe is relatively small. Also, since it is necessary to finally meet the relatively large deployment diameter of the stand part, with an increase in the carving amount, the rod width of the stand becomes smaller and the rigidity becomes weaker. Conversely, when the rod width and rigidity of the stand meet the requirements, with a decrease in the amount of carving removed, the deployment diameter of the stand becomes smaller. <0000​Furthermore, the stand may be fabricated by sculpting using precast tubing with a relatively large diameter, and finally, the connecting ring sleeve at the proximal end may be hollowed out. However, this method generates waste, is costly, and complicates the process.

[0007] In practice, according to known embodiments in disclosure number CN114588533A, the prior art employs a distributed support leg structure for the distal end connection of the stand (specifically, there are multiple support legs, spaced apart along the circumferential direction). However, in order to maintain a high-strength fixed connection with the catheter or proximal end bearing chamber, the proximal end connection structure of the stand currently often employs a circumferentially continuous ring sleeve structure. The reasons for this will be explained in detail below, but the circumferentially continuous ring sleeve structure primarily prevents the pump head from floating up due to the lever principle when folded, and also maintains a fixed connection relationship with the catheter at all times. In light of this, the proximal end connection structure of the stand cannot employ the same or similar distributed support leg structure as the distal end connection structure.

[0008] Furthermore, the connection structures at both ends of the stand are connected to fixed components (for example, the proximal and distal end bearing chambers, respectively), and these connection structures at both ends have portions that are structurally connected to or overlap with the fixed components, with the portions extending from the fixed components forming a cantilever structure. The inlet and outlet of the stand require support from this cantilever structure, and the main body portion housing the impeller is further supported by the inlet and outlet. Therefore, how well the cantilever structure in this portion provides support rigidity is extremely important for the overall rigidity of the stand when it is deployed.

[0009] In particular, the proximal end connection structure may, in some cases, be subjected to forced compression and deformation when, for example, the pump head is folded from the proximal end, causing the proximal end cantilever structure to fold the sheath. Such compressive deformation must be recovered by the memory elasticity of the cantilever structure itself (the entire stand is made of memory material) after the sheath is removed, in order to support the deployment of the inlet and main body. Therefore, maintaining good support rigidity of the proximal end cantilever structure is extremely important. [Overview of the project] [Problems that the invention aims to solve]

[0010] In light of the shortcomings of prior art, this disclosure aims to provide a catheter pump that, while satisfying the requirement of being small in size when the stand body is radially folded, has a relatively large unfolded diameter when the stand body is radially unfolded, ensures that the rigidity of the stand body meets requirements, allows the cantilever structure included in the proximal end connecting leg of the stand to have superior support rigidity, and further allows the cantilever structure included in the distal end connecting leg of the stand to have superior support rigidity. [Means for solving the problem]

[0011] To achieve the above objective, this application provides the following embodiments.

[0012] This catheter pump includes a catheter, a proximal end connector connected to the distal end of the catheter, and a pump head. The pump head includes a stand and an impeller housed within the stand, which is used to rotate to pump blood. The stand is operable to switch between a radially folded state and a radially extended state. In the radially extended state, the stand includes a stand body and proximal end connecting legs located at the proximal end of the stand body. There are multiple proximal end connecting legs, which are spaced apart along the circumferential direction of the stand. Each proximal end connecting leg includes a proximal end connecting rod and a proximal end support rod located at the distal end of the proximal end connecting rod. The proximal end support rod connects to and supports the stand body, and the circumferential width of the proximal end support rod is greater than the circumferential width of the proximal end connecting rod. The proximal end connecting rod is fixedly connected to the proximal end connector. The proximal end support rod includes a first connecting portion fixedly connected to the proximal end connection and a first outer portion located outside the distal end of the proximal end connection.

[0013] Preferably, the proximal end connecting leg further includes a proximal end wide portion fixedly connected to the proximal end connecting portion, wherein the circumferential width of the proximal end wide portion is greater than the circumferential width of the proximal end connecting rod.

[0014] Preferably, the proximal end wide portion is located at the proximal end of the proximal end connecting rod.

[0015] Preferably, the axial length of the first connecting portion is greater than the axial length of the proximal end wide portion and less than the axial length of the proximal end connecting rod.

[0016] Preferably, the outer wall of the proximal end connection portion is provided with multiple proximal end support leg grooves for fitting multiple proximal end connection legs in a one-to-one correspondence, and a proximal end collar is fitted outside the proximal end connection portion. The proximal end collar is used to hold the proximal end connection leg within the proximal end support leg groove by fixing the proximal end connection leg along the radial direction of the stand.

[0017] Preferably, the outer wall of the proximal end connection portion forms a proximal end spacing projection between two circumferentially adjacent proximal end support leg grooves, and the proximal end spacing projection includes a first projection located between two adjacent first connection portions and a second projection located between two adjacent proximal end connection rods, wherein the circumferential width of the second projection is greater than the circumferential width of the first projection.

[0018] Preferably, the material used to fabricate the proximal collar is a metallic material.

[0019] Preferably, the circumferential width of the proximal end connecting rod remains unchanged along its extending direction.

[0020] Preferably, the circumferential width of the proximal end support rod remains unchanged along its extending direction.

[0021] Preferably, the circumferential width of the proximal end wide portion remains unchanged along the extending direction of the proximal end connecting rod.

[0022] Preferably, a proximal end transition section is provided between the proximal end support rod and the proximal end connecting rod. In the direction from the proximal end to the distal end of the proximal end transition section, the circumferential width of the proximal end transition section gradually increases from a width equal to that of the proximal end connecting rod to a width equal to that of the proximal end support rod.

[0023] Preferably, the proximal end connection is a proximal end bearing chamber provided at the distal end of the catheter, a proximal end bearing is provided in the proximal end bearing chamber, a drive shaft is drilled into the proximal end bearing, and the drive shaft is connected to an impeller to drive the rotation of the impeller.

[0024] Preferably, the stand further includes distal connection legs located at the distal end of the stand body. The number of distal connection legs is plural, and the plural distal connection legs are arranged at intervals along the circumferential direction of the stand. The distal connection legs include a distal connection rod and a distal support rod located at the proximal end of the distal connection rod. The distal support rod connects and supports the stand body, and the circumferential width of the distal support rod is larger than the circumferential width of the distal connection rod. The distal connection rod is fixedly connected to the distal connection portion. The distal support rod includes a second connection portion fixedly connected to the distal connection portion and a second outer portion located outside the proximal end of the distal connection portion.

[0025] Preferably, the distal connection leg further includes a distal wide-width portion fixedly connected to the distal connection portion, and the circumferential width of the distal wide-width portion is larger than the circumferential width of the distal connection rod.

[0026] Preferably, the distal wide-width portion is located at the distal end of the distal connection rod.

[0027] Preferably, the axial length of the second connection portion is larger than the axial length of the distal wide-width portion and smaller than the axial length of the distal connection rod.

[0028] Preferably, on the outer wall of the distal connection portion, a plurality of distal support leg grooves for fitting the plurality of distal connection legs in a one-to-one correspondence are provided. Outside the distal connection portion, a distal collar is fitted. The distal collar is used to hold the distal connection legs in the distal support leg grooves by fixing the distal connection legs along the radial direction of the stand.

[0029] Preferably, on the outer wall of the distal connection portion, a distal interval protrusion is formed between two circumferentially adjacent distal support leg grooves. The distal interval protrusion includes a fourth protrusion portion located between two adjacent second connection portions and a fifth protrusion portion located between two adjacent distal connection rods. The circumferential width of the fifth protrusion portion is larger than the circumferential width of the fourth protrusion portion.

[0030] Preferably, the material used to fabricate the distal end collar is a metal material.

[0031] Preferably, the circumferential width of the distal end connecting rod remains unchanged along its extending direction.

[0032] Preferably, the circumferential width of the distal end support rod remains unchanged along its extending direction.

[0033] Preferably, the circumferential width of the distal end wide portion remains unchanged along the extending direction of the distal end connecting rod.

[0034] Preferably, a distal end transition section is provided between the distal end support rod and the distal end connecting rod. In the direction from the distal end to the proximal end of the distal end transition section, the circumferential width of the distal end transition section gradually increases from a width equal to that of the distal end connecting rod to a width equal to that of the distal end support rod.

[0035] Preferably, the distal end connection is a distal end bearing chamber connected to the distal end of the stand, a distal end bearing is provided in the distal end bearing chamber, a drive shaft is drilled in the distal end bearing, and the drive shaft is connected to the impeller to drive the rotation of the impeller.

[0036] Preferably, the distal end connector is a protective tip connected to the distal end of the distal end connector leg, and the protective tip is flexible and separates the blood inlet of the pump head from the ventricular wall.

[0037] Preferably, a hydrophobic coating layer is provided on the surface of the stand.

[0038] Preferably, a hydrophobic coating layer is provided on the surface of the stand body.

[0039] Preferably, the hydrophobic coating layer is preferably a superhydrophobic coating layer. [Effects of the Invention]

[0040] The catheter pump according to this embodiment replaces the conventional connecting ring sleeve, which has a circumferentially continuous structure in at least part of it, by providing a plurality of proximal end connecting legs that are spaced apart in the circumferential direction of the stand, that is, by distributing the plurality of proximal end connecting legs. As described above, if a circumferentially continuous connecting ring sleeve structure (where the connecting ring sleeve is the proximal end portion of the precast pipe) is adopted, the diameter of this connecting ring sleeve is the diameter after the stand is folded. In other words, the diameter of the stand when folded is limited by the diameter of the proximal end connecting ring sleeve, that is, limited by the diameter of the precast pipe. If the diameter of the precast pipe is relatively large, it is difficult to satisfy the small diameter when the stand is folded, and furthermore, it is not possible to satisfy the demand for a small interposition size of the pump head. If the diameter of the precast pipe is relatively small, it is possible to satisfy the small folded size and interposition size of the stand, but it is not possible to simultaneously satisfy the large deployed diameter and large deployed support rigidity of the stand. This is because, in order to meet a large unfolded diameter, a relatively large amount of pipe material needs to be cut and removed, and the width of the stand, especially the main body rod, is relatively small, which reduces the support rigidity after unfolding. Conversely, in order to meet a large unfolded support rigidity, the width of the stand, especially the main body rod, needs to be relatively large, and thus the amount of pipe material to be cut and removed should not be too large, but the unfolded diameter of the stand will not be large enough.

[0041] The stand has a technical effect of providing greater support rigidity after deployment, which will be detailed below, but will not be explained further here. The large deployed diameter of the stand increases the diameter of the impeller, and a technical effect of increasing the flow rate for pumping blood is obtained.

[0042] In contrast, the stand of this application does not employ a circumferentially continuous ring sleeve structure as the proximal end, but instead employs multiple dispersed leg-like structures that are not connected to each other. Thus, the diameter of the stand when folded is not limited by the diameter of the precast pipe, meaning that it can be manufactured by laser cutting using a precast pipe with a relatively large diameter. Because the diameter of the selected precast pipe is larger than that of the prior art, the amount of material to be cut and removed to achieve the same unfolded diameter is reduced, the rod width of the stand body is increased, and the support rigidity of the stand is further improved. Alternatively, to achieve the same support rigidity, the amount of material to be cut and removed may be increased, the rod width of the stand body is reduced, and the unfolded diameter of the stand is further increased.

[0043] Notably, the stand in this application is manufactured by laser cutting the entire precast pipe. In other words, compared to the conventional technique in which only the main body and distal end connecting legs of the stand are formed by laser cutting, this application forms the entire structure of the stand, including the main body, proximal end connecting legs, and distal end connecting legs, by laser cutting. Thus, the manufacturing process of the stand is rather simple.

[0044] The stand formed by the above method exhibits a perforated cylindrical structure (without distinguishing between the main body, proximal end connecting leg, and distal end connecting leg), and the outer diameter of each part in the axial direction is equal. Subsequently, this perforated cylindrical structure (abbreviated as the stand before molding) is subjected to a mold-setting process to obtain the final stand structure. Specifically, this stand before molding is fitted onto an internal mold, and then an external mold (refer to the stand shape in Figure 1 for the external contour shape of the internal mold and the internal mold hole shape of the external mold) is fitted outside the internal mold. After that, a heat treatment process is performed on this stand before molding, heating it to the phase transition temperature of the stand material (e.g., nickel-titanium alloy), and after being kept warm for a while, it is cooled and demolded to obtain the final stand.

[0045] Therefore, compared to conventional technology, this application employs a structure of distributed connecting legs at the proximal end, which ensures that the stand body has a relatively large unfolded diameter and support rigidity when radially unfolded, while maintaining the condition that the stand body is small in size when radially folded. Furthermore, by manufacturing the stand with a connecting ring sleeve at the proximal end by engraving a relatively large diameter precast pipe, no waste material is generated, costs are relatively low, and the process is simple.

[0046] Furthermore, a portion of the proximal end support rod (first connection portion) that is wider in the proximal end connecting leg is fixedly connected to the proximal end connection portion, thereby providing support to the first outer portion which exhibits a cantilever structure extending outside the proximal end connection portion. This allows the proximal end cantilever structure of the stand to have better support rigidity (avoiding supporting the cantilever structure with a narrower proximal end connecting rod), thus giving the cantilever structure at the proximal end of the stand better support rigidity. In this way, by supporting the stand body with a cantilever portion that has relatively high support, the stand body can be made to have relatively high support rigidity when extended.

[0047] As described above, the fact that a portion of the proximal end support rod (the first connection portion) is fixedly connected to the proximal end connection and another portion (the first outer portion) extends from the distal end of the proximal end connection means that the proximal end support rod straddles the proximal end connection. Thus, during folding or unfolding, the boundary point between the deformable segment and the non-deformable segment of the stand, with the distal end of the proximal end connection as the boundary, is located on the proximal end support rod. Those skilled in the art should know that the deformation boundary point is where stress concentration and stress fatigue are most likely to occur, and that stress concentration and stress fatigue lead to a decrease in material stiffness. Therefore, by increasing the width of the proximal end support rod and compensating for the stiffness of the proximal end support rod in the positive direction, fracture of the proximal end support rod due to repeated folding or unfolding of the stand can be avoided.

[0048] The relatively narrow proximal end connecting rod primarily serves to position the proximal end connection in the axial direction and to provide a fixed connection, ensuring that the proximal end connecting leg provides a stronger connection with the proximal end connection and preventing poor connection between the proximal end connecting leg and the proximal end connection.

[0049] In other words, the proximal end connecting rod, which has a relatively small circumferential width, can be connected to the proximal end connecting portion flexibly and easily. The proximal end connecting portion is connected to the first connecting portion, which has a relatively large circumferential width, and extends to the outside of the distal end of the proximal end connecting portion. The first outer portion, which exhibits a cantilever structure, provides superior rigid support and ensures that the main body of the stand has superior support rigidity. The superior support rigidity of the main body is very important for the stable operation of the pump head. For example, it prevents inward dents from occurring when the pump head is subjected to a lateral impact in the ventricle (i.e., the stand is subjected to a lateral force), and also prevents the impeller from touching the stand, thus preventing the impeller from being forcibly stopped and blood pumping from failing.

[0050] In another embodiment, a proximal end connecting rod with a relatively small circumferential width has a longer axial length, which increases the length over which the proximal end connecting leg directly connects to the proximal end connecting portion. The proximal end connecting portion can then provide a certain level of strength support to the proximal end connecting rod and further ensure the strength of the connection between the stand and the proximal end connecting portion.

[0051] The relatively wide proximal end section is connected to the proximal end connecting rod. The outer wall of the proximal end connecting section is recessed inward to form a proximal end support leg groove for accommodating the proximal end connecting leg, and the proximal end wide section and the proximal end connecting rod are all fitted into the proximal end support leg groove. In this way, the proximal end wide section, the proximal end connecting rod, and the proximal end connecting section form a locking physical connection structure. This locking connection structure can continuously resist axial pulling between the catheter and the stand. In particular, when folding the pump head from the proximal end of the stand, this continuous resistance to axial pulling helps to maintain a stable connection between the catheter and the stand and prevents the connection from breaking.

[0052] By increasing the length of the narrower proximal end connecting rod, the axial connection length (overlapping length) between the proximal end connecting leg and the proximal end connecting section is increased, thereby ensuring the connection strength between the two. On the other hand, the groove area of ​​the proximal end connecting section is reduced, ensuring that the structural strength of the proximal end connecting section is not excessively lost, and further providing good structural support to the proximal end cantilever structure of the stand.

[0053] In another embodiment, by adopting the same (mirror-symmetric) structural design as the proximal end connecting leg, the distal end cantilever structure of the stand has superior support rigidity. Thus, the stand can obtain relatively strong rigid support from its distal end. Combined with the same structure of the proximal end connecting leg, the stand has superior rigid support at both ends, and as a result, the main body of the stand has higher support rigidity when extended.

[0054] The distal end connecting leg and the proximal end connecting leg can achieve essentially the same technical effect by employing the same or similar structural design. For details, please refer to the description above, and no further explanation will be provided. [Brief explanation of the drawing]

[0055] [Figure 1] A schematic diagram of the structure of a stand according to one embodiment of this disclosure is shown. [Figure 2] A schematic diagram of the structure of a catheter pump according to one embodiment of the present disclosure is shown. [Figure 3] A schematic diagram of the connection point between the proximal end bearing chamber and the proximal end connecting leg according to one embodiment of the present disclosure is shown. [Figure 4] A schematic diagram of the connection point between the distal end bearing chamber and the distal end connecting leg according to one embodiment of the present disclosure is shown. [Figure 5] This diagram shows experimental data of a stand provided with a hydrophobic coating layer according to one embodiment of the present disclosure. [Figure 6] A schematic diagram of the structure of the proximal end bearing chamber in an embodiment of the present disclosure is shown. [Figure 7] A schematic diagram of the structure in which the distal end bearing chamber of an embodiment of this disclosure is assembled with the protective tip is shown. [Figure 8] A schematic diagram of the structure of a catheter and the first connection portion at its distal end according to an embodiment of the present disclosure is shown. [Modes for carrying out the invention]

[0056] The present application will be described in detail below in accordance with the specific embodiments shown in the attached drawings. However, these embodiments are not limiting to this application, and any structural, method, or functional modifications made by those skilled in the art based on these embodiments are all covered by the scope of this disclosure.

[0057] The terms “proximal,” “distal,” “anterior,” and “posterior” used in this disclosure refer to the clinician operating the catheter pump of this embodiment. The terms “proximal” and “posterior” refer to parts relatively close to the clinician, while the terms “distal” and “anterior” refer to parts relatively far from the clinician. For example, the external portion is located at the proximal and posterior ends, and the internally interposed portion is located at the distal and anterior ends.

[0058] It should be understood that the directions "near," "far," "back," and "front" are defined for ease of explanation. However, because the catheter pump can be used in many directions and positions, these terms describing relative positions are limited and not absolute. For example, the above definitions of each direction are for ease of explanation of the technical proposal of this application and do not limit the direction of the catheter pump in other scenarios where tipping or repositioning may occur, such as product testing, transportation, and manufacturing. In this application, the above definitions shall be subject to any specific provisions and limitations where such provisions and limitations are particularly specified.

[0059] In this application, unless otherwise specified and limited, terms such as "connected" and "linked" should be understood in a broad sense. For example, they may be fixedly connected, detachably connected, movably connected, or integrated, directly connected, indirectly connected via an intermediate medium, or be internal communication between two elements or an interaction relationship between two elements. Those skilled in the art will be able to understand the specific meaning of the above terms in this application depending on the specific circumstances.

[0060] The technical features of the different embodiments of this application, as described below, can be combined with each other, provided they do not conflict with each other.

[0061] The catheter pumps of the embodiments of this disclosure are used to achieve a partial blood pumping function of the heart. In scenarios where they are applied to left ventricular assist, the catheter pump pumps blood from the left ventricle to the aorta, supporting blood circulation, reducing the workload on the subject's heart, or providing additional and sustained blood pumping power support when the heart's blood pumping capacity is insufficient. Of course, the catheter pump can be interposed by interventional surgery as desired in other target locations of the subject, such as the right ventricle, blood vessels, or other organs.

[0062] Referring to Figures 1 to 4 and Figures 6 to 8, the catheter pump of the embodiment of the present disclosure includes a catheter 2, a proximal end connector, and a pump head. The proximal end connector is connected to the distal end of the catheter 2. The pump head includes a stand 1 and an impeller housed within the stand 1, the impeller being driven to rotate to pump blood. The stand 1 is operable to switch between a radially folded state and a radially extended state. In the radially extended state, the stand 1 includes a stand body 11 and proximal end connecting legs 131 located at the proximal end of the stand body 11. There are multiple proximal end connecting legs 131, which are spaced apart along the circumferential direction of the stand 1. The proximal end connecting legs 131 and the stand body 11 are integrally constructed.

[0063] Furthermore, the ends of the catheter 2 are its proximal and distal ends, the stand body 11 has two opposing ends, the two opposing ends of the stand body 11 are its proximal and distal ends, and the direction of extension of the central axis surrounded in the circumferential direction of the stand 1 is parallel to or the same as the distribution of the two opposing ends of the stand body 11.

[0064] Specifically, the central axis enclosed in the circumferential direction of stand 1 extends along the axial direction X.

[0065] The proximal end connecting leg 131 includes a proximal end connecting rod 134 and a proximal end support rod 133 located at the distal end of the proximal end connecting rod 134, with the proximal end connecting rod 134 and the proximal end support rod 133 being an integral structure. The proximal end support rod 133 connects to and supports the stand body 11, and the circumferential width of the proximal end support rod 133 is greater than the circumferential width of the proximal end connecting rod 134. The proximal end connecting rod 134 is fixedly connected to the proximal end connection portion, and the proximal end support rod 133 includes a first connecting portion 1301 fixedly connected to the proximal end connection portion and a first outer portion 1302 located outside the distal end of the proximal end connection portion. The first connecting portion 1301 and the first outer portion 1302 are an integral structure, and both are located at the distal end face of the proximal end connection portion, specifically with the dashed line shown in Figure 3 as the boundary line.

[0066] Furthermore, the proximal end connecting rod 134 has a proximal end and a distal end, respectively, and the proximal end connecting section has two opposing ends, the two opposing ends of the proximal end connecting section are its proximal end and distal end, respectively.

[0067] Selectively, the distribution directions of the opposing ends of the proximal end connection are parallel to or the same as the axial direction X.

[0068] In this embodiment, the circumferential width refers to the circumferential size of the stand 1 of the proximal end connecting rod 134, the width L shown by the arrow in Figure 3. The circumferential widths of other structures, such as the edge, distal end connecting leg 121 and components contained therein, are understood similarly and will not be discussed further here.

[0069] Multiple proximal end connecting legs 131 are arranged in parallel, and the spacing between adjacent proximal end connecting legs 131 is equal along the circumferential direction of the stand 1. This ensures that the structure of the proximal end portion of the stand 1 becomes more uniform when subjected to force, thereby ensuring greater stability of the proximal end portion of the stand 1 and simplifying the manufacturing process. The extending direction of the proximal end connecting legs 131 is parallel to the axial direction X, thereby facilitating connection with the proximal end connection portion (e.g., the first connection portion 21 of the catheter 2 or the proximal end bearing chamber 6). The radial thickness of the proximal end connecting legs 131 remains constant in the axial direction X. By thus varying the circumferential width of different parts of the proximal end connecting legs 131 in the axial direction X, it is possible to adjust the rigidity of the corresponding position of the proximal end connecting legs 131, thereby making the adjustment of the rigidity of the proximal end connecting legs 131 simple and flexible.

[0070] Stand 1 has two opposing ends that are installed opposite each other, and these opposing ends of Stand 1 are its proximal end and distal end, respectively. The distribution direction of the opposing ends of Stand 1 is the same as the distribution direction of the opposing ends of the Stand body 11.

[0071] Furthermore, the proximal end connecting leg 131 is equal in diameter to the radial thickness of the stand body 11 and the distal end connecting leg 121. In other words, the thickness of the physical structure at all positions in the axial direction X of the stand 1 is the same and uniform. Therefore, the stand 1 can be fabricated by laser cutting using a precast catheter with a uniform wall thickness, and the fabrication process of the stand 1 is simple. Moreover, the fact that the thickness of the physical structure at all positions of the stand 1 is the same means that the wall thickness is uniform after the stand 1 is folded, and further ensures that the size of the entire pump head is uniform after it is folded.

[0072] The proximal end connecting leg 131 further includes a proximal end wide portion 136 which is fixedly connected to the proximal end connecting portion, and the proximal end wide portion 136 is connected to the proximal end connecting rod 134 and forms an integral structure, preferably the proximal end wide portion 136 is at the proximal end of the proximal end connecting rod 134 Located The proximal end connecting rod 134 extends along the axial direction X, and the proximal end wide portion 136 extends along the circumferential direction of the stand 1. Both are installed substantially vertically, and the circumferential width of the proximal end wide portion 136 is greater than the circumferential width of the proximal end connecting rod 134. As a result, the proximal end wide portion 136 and the proximal end connecting rod 134 form a substantially "T" shape structure. This "T" shape structure can hook onto the corresponding position of the proximal end connection portion (as described later, it is fitted into the proximal end support leg groove 61), enabling a fixed connection between the proximal end connecting leg 131 and the proximal end connection portion in the circumferential direction and axial direction X of the stand 1. The circumferential width of the proximal end connecting rod 134 is smaller than the circumferential width of the proximal end support rod 133 and smaller than the circumferential width of the proximal end wide portion 136. Thus, because the circumferential width of the proximal end connecting leg 131 in the axial direction X is not uniform but varies, positioning and assembly with the proximal end support leg groove 61 can be easily and quickly achieved, and the "T"-shaped structure enables a fixed connection with the proximal end connecting portion along the axial direction X.

[0073] Along the axial direction X, the axial length of the first connecting portion 1301 is greater than the axial length of the proximal end wide portion 136, but less than the axial length of the proximal end connecting rod 134. In other words, in the portion that overlaps with or connects to the proximal end connecting portion, the length of the proximal end connecting rod 134 is the longest, and the length of the proximal end wide portion 136 is the shortest. By increasing the length of the proximal end connecting rod 134, which has a relatively small circumferential width (i.e., maximizing the length of the proximal end connecting rod 134, which has the smallest circumferential width), the axial connection length (overlap length) between the proximal end connecting leg 131 and the proximal end connecting portion can be increased, ensuring the connection strength between the two, while reducing the groove area of ​​the proximal end connecting portion to ensure that the structural strength of the proximal end connecting portion is not excessively lost, and further providing rigid support to the proximal end cantilever structure of the stand 1.

[0074] As shown in Figure 1, the first connecting portion 1301 is linear in shape and extends along the axial direction X, and is installed on the outer wall of the proximal end connecting portion together with the proximal end connecting rod 134. In the radially folded state, the first outer portion 1302 of the stand 1 is linear in shape and extends along the axial direction X. In the radially unfolded state, the first outer portion 1302 of the stand 1 is curved, and the distance from the first outer portion 1302 to the central axis of the stand 1 gradually increases in the direction from the proximal end to the distal end of the proximal end support rod 133. Here, the central axis of the stand 1 is an axis that passes through the center of the stand 1 and extends along the axial direction X. In other words, in the radially unfolded state, the first outer portion 1302 bends from the first connecting portion 1301 toward the distal end of the proximal end support rod 133, extending to the branch structure 1131, which is the proximal end intersection of the edges that form the mesh at the exit portion described later. The first outer portion 1302 can provide rigid support to the main body portion of the stand 1 in the radially unfolded state.

[0075] The proximal end support rod 133 has two ends, which are its proximal end and distal end. Along the distribution direction of both ends of the proximal end support rod 133, the proximal end support rod 133 includes a first connecting portion 1301 and a first outer portion 1302 that are connected to each other. The end of the first connecting portion 1301 that is separated from the first outer portion 1302 is the proximal end of the proximal end support rod 133, and the end of the first outer portion 1302 that is separated from the first connecting portion 1301 is the distal end of the proximal end support rod 133. One of the ends of the edge is its proximal end.

[0076] As shown in Figure 3, the outer wall of the proximal end connection section is provided with multiple proximal end support leg grooves 61 for fitting multiple proximal end connection legs 131 in a one-to-one correspondence, and the shape of the proximal end support leg grooves 61 matches the corresponding shape of the proximal end connection legs 131. A proximal end collar 63 is fitted outside the proximal end connection section, and the proximal end collar 63 is used to fix the proximal end connection legs 131 along the radial direction of the stand 1, thereby keeping the proximal end connection legs 131 in the proximal end support leg grooves 61 at all times. The proximal end support leg grooves 61 are used to accommodate the proximal end wide section 136, the proximal end connection rod 134, and the first connection section 1301.

[0077] When the pump head is folded, the sheath applies a force along the axial direction X to the unfolded stand 1. This axial force, due to the lever principle, causes the ends of stand 1 to tend to spread radially outward. However, this tendency for the proximal end of stand 1 to spread radially outward weakens the fixed connection between the proximal end of stand 1 and the proximal end connection, and further increases the possibility of disconnection of both connections.

[0078] If the stand employs a conventional connecting subcatheter structure, the connecting subcatheter structure is continuous in its circumferential direction. As a result, any part of the catheter-shaped connecting subcatheter in its circumferential direction is intertwined with adjacent parts, and this effectively counteracts and eliminates the radial outward spreading that occurs when the pump head is folded. Therefore, the fixed connection between the stand and the proximal end connection can be maintained well.

[0079] In contrast, the proximal end portion of the stand 1 in this embodiment, which connects to the proximal end connection, employs a support leg structure that is dispersed in the circumferential direction of the stand 1. The dispersed support legs do not form intertwining forces like those of a connecting subcatheter. In this way, when the pump head is folded, the support legs spread outward radially and detach from the proximal end connection (specifically, the "T"-shaped structure of the proximal end of the support legs lifts out of the support leg groove), which greatly improves the possibility of this happening and further affects the fixed connection relationship between the stand 1 and the proximal end connection.

[0080] Therefore, the purpose of fitting the proximal end collar 63 outside the proximal end connection portion in this embodiment is to resist the outward force in the radial direction of the proximal end portion of the proximal end connection leg 131, to prevent the proximal end connection leg 131 from spreading outward in the radial direction and detaching from the proximal end connection portion, to ensure that the "T"-shaped structure formed on the proximal end portion of the proximal end connection leg 131 is always held in the proximal end support leg groove 61, and furthermore, to ensure that a fixed connection between the two is maintained for a long period of time.

[0081] Furthermore, conventional proximal collars often employ heat-shrinkable catheters, primarily due to their simple manufacturing process. However, heat-shrinkable catheters are essentially plastic catheters, possessing relatively low strength and making them less resistant to the outward lifting force of the proximal end connecting leg 131. In practice, it has been found that proximal collars made from heat-shrinkable catheters can penetrate the proximal end of the proximal end connecting leg 131. In light of this, the proximal collar 63 of this embodiment is made from a stronger metal material (e.g., copper or copper-aluminum alloy), thereby avoiding the above problem and further enabling more secure fixation and restraint of the proximal end connecting leg 131 within the proximal end support leg groove 61 in the radial direction of the stand 1.

[0082] Note that one of the two ends of the proximal end connecting leg 131 is its proximal end.

[0083] As shown in Figures 3 and 6, the outer wall of the proximal end connection portion forms a proximal end spacing projection 62 between two circumferentially adjacent proximal end support leg grooves 61. The circumferential width of the second projection 622 of the proximal end spacing projection 62 located between the proximal end connection rods 134 is greater than the circumferential width of the proximal end connection rods 134, the circumferential width of the third projection 623 located between the proximal end wide portions 136 of the proximal end spacing projection 62 is smaller than the circumferential width of the proximal end wide portions 136, and the circumferential width of the first projection 621 located between the first connection portions 1301 of the proximal end spacing projection 62 is smaller than the circumferential width of the first connection portion 1301.

[0084] Specifically, the proximal end spacing projection 62 includes a first projection 621 located between two adjacent first connecting portions 1301, a second projection 622 located between two adjacent proximal end connecting rods 134, and a third projection 623 located between two adjacent proximal end wide portions 136. Essentially, the circumferential width of the second projection 622 is greater than the circumferential width of the first projection 621 and greater than the circumferential width of the third projection 623. The "T"-shaped structure formed by the proximal end wide portion 136 and the proximal end connecting rod 134 engages with the proximal end of the second projection portion 622 of the proximal end spacing projection 62, thereby creating a connection. This ensures that the circumferential width of the second projection portion 622 is relatively large, giving the second projection portion 622 relatively high strength. Furthermore, it provides a highly strong positional restraining effect to the proximal end "T"-shaped structure of the stand 1. When the stand 1 is folded and an axial force toward the distal end is applied to the proximal end connection, the proximal end spacing projection 62 prevents the material from collapsing at the proximal end of the second projection portion 622, ensuring that the engagement connection is stably maintained.

[0085] The second projection 622 has two opposing ends, and one of the two opposing ends of the second projection 622 is its proximal end. When the "T"-shaped structure formed by the proximal end wide portion 136 and the proximal end connecting rod 134 engages with the proximal end of the second projection 622 of the proximal end spacing projection 62 and forms a connection, the distribution direction of the two opposing ends of the second projection 622 is parallel to or the same as the extending direction of the proximal end connecting rod 134.

[0086] The circumferential width of the proximal end connecting rod 134 is uniform, the circumferential width of the proximal end support rod 133 is also uniform, and the circumferential width of the proximal end wide portion 136 is also uniform. In other words, the circumferential width of the proximal end connecting rod does not change along its extending direction, the circumferential width of the proximal end connecting rod 134 does not change in the axial direction X, the circumferential width of the proximal end support rod does not change along its extending direction, the circumferential width of the proximal end support rod 133 does not change in the axial direction X, the circumferential width of the proximal end wide portion does not change along the extending direction of the proximal end connecting rod, and the circumferential width of the proximal end wide portion 136 does not change in the axial direction X. In this way, the structure of the proximal end connecting leg 131 can be simplified as much as possible, and most importantly, the manufacturing process of the proximal end connecting leg 131 and the corresponding proximal end support leg groove 61 can be simplified.

[0087] The reason the above effect is obtained is that the proximal end connecting leg 131 itself already includes multiple parts of different widths (i.e., the proximal end connecting rod 134, the proximal end support rod 133, and the proximal end wide section 136). If the proximal end connecting rod 134 and / or the proximal end support rod 133 and / or the proximal end wide section 136 are designed to have varying circumferential widths, for example, if the proximal end connecting rod 134 and / or the proximal end support rod 133 are designed to gradually widen or narrow along the direction from the proximal end to the distal end, the complexity of the manufacturing process for the proximal end connecting leg 131 is greatly increased. Furthermore, a complex structural design like that of the proximal end connecting leg 131 does not significantly improve the performance of other aspects, such as the connection strength with the proximal end connection part. On the contrary, the width of the proximal end support leg groove 61 also changes accordingly, and the formation of the proximal end support leg groove 61 becomes more complex. The above problem can be avoided if the axial widths of the proximal end connecting rod 134, the proximal end support rod 133, and the proximal end wide portion 136 are uniform.

[0088] A proximal end transition section 135 is provided between the proximal end support rod 133 and the proximal end connecting rod 134. In the direction from the proximal end to the distal end of the proximal end transition section 135, the circumferential width of the proximal end transition section 135 gradually increases from a width equal to that of the proximal end connecting rod 134 to a width equal to that of the proximal end support rod 133. This gradual increase may be linear or exponential, and depending on the structure of the proximal end transition section 135, it may appear as a slope transition or an arc transition, respectively. By installing the proximal end transition section 135, the circumferential width of the connected proximal end support rod 133 and proximal end connecting rod 134 can change gradually rather than abruptly, thereby avoiding stress concentration at the connection point between the proximal end support rod 133 and the proximal end connecting rod 134 due to abrupt changes in circumferential width, and further avoiding fracture at both connection points.

[0089] The proximal end transition section 135 has two opposing ends, which are its proximal and distal ends, respectively. The proximal end of the proximal end transition section 135 is connected to the proximal end connecting rod 134, and the distal end of the proximal end transition section 135 is connected to the proximal end support rod 133.

[0090] As shown in Figure 3, in one embodiment, the proximal end connection is a proximal end bearing chamber 6 provided at the distal end of the catheter 2. A proximal end bearing is provided inside the proximal end bearing chamber 6, and a drive shaft (specifically, a rigid shaft described later) is drilled into the proximal end bearing. The drive shaft is connected to the impeller and drives the rotation of the impeller. The proximal end support leg groove 61 is provided on the outer wall surface of the distal end of the proximal end bearing chamber 6, and the proximal end collar 63 is fitted into the outer wall surface of the proximal end bearing chamber 6 where the proximal end support leg groove 61 is provided.

[0091] As shown in Figure 8, the distal end outer wall of the catheter 2 is reduced in diameter to form a first connection portion 21. Specifically, the thickness of the outer wall surface of the distal end section of the catheter 2 is reduced to form the first connection portion 21. Between the first connection portion 21 and the adjacent distal end portion of the catheter 2, a stopper step 22 is formed to provide stopper positioning restriction for the proximal end bearing chamber 6 and to facilitate positioning and mounting of both.

[0092] As shown in Figure 6, the axial ends of the proximal bearing chamber 6 are its proximal and distal ends, respectively. The proximal bearing chamber 6 has a stepped structure and includes a first portion 67 located at the proximal end and a second portion 68 located at the distal end. The first portion 67 and the second portion 68 have the same inner diameter, but the outer diameter of the first portion 67 is smaller than the outer diameter of the second portion 68. The outer diameter of the second portion 68 is smaller than the outer diameter of the catheter 2. The first portion 67 is fitted outside the first connecting portion 21, and the proximal end support leg groove 61 is provided on the outer wall surface of the second portion 68. The first portion 67 is provided with a through hole 671 that penetrates its inner and outer surfaces along the radial direction of the proximal bearing chamber 6. When assembling the proximal bearing chamber 6 and the catheter 2, first, the heat-shrinkable catheter 20 is fitted outside the first portion 67 of the proximal bearing chamber 6, and then the first portion 67 of the proximal bearing chamber 6 is fitted outside the first connection portion 21 of the catheter 2. After that, a heat-shrinking process is performed on the heat-shrinkable catheter 20, and the material of the heat-shrinkable catheter 20 melts and flows into the through hole 671, adhering to the outer wall of the first connection portion 21 of the catheter 2. In addition, the inner wall material of the heat-shrinkable catheter 20 after heat shrinkage adheres to the outer wall of the first portion 67, thereby fixing the proximal bearing chamber 6 to the catheter 2. Preferably, the material of the heat-shrinkable catheter 20 is the same as the material of the catheter 2. In this case, the heat-shrinkable catheter 20 has the same molecular structure as the catheter 2, further improving the bonding strength between the material of the heat-shrinkable catheter 20 and the material of the catheter 2 after melting, and further improving the fixing connection effect between the proximal bearing chamber 6 and the catheter 2.

[0093] In addition to the relatively small outer diameter of the first portion 67, the first connecting portion 21 is formed by removing material from the outer wall of the distal end of the catheter 2. Therefore, after the first portion 67 of the proximal end bearing chamber 6 is fitted onto the first connecting portion 21, the outer wall of the first portion 67 is not flush with the outer wall of the distal end of the catheter 2; specifically, the outer wall of the first portion 67 is lower than the outer wall of the distal end of the catheter 2.

[0094] The outer diameter of the heat-shrinkable catheter 20 after heat shrinkage is approximately equal to the outer diameter of the catheter 2. Therefore, by fitting the heat-shrinkable catheter 20 outside the first portion 67, not only is a fixed connection between the proximal end bearing chamber 6 and the catheter 2 achieved, but the difference in height between the outer wall of the first portion 67 and the distal end outer wall of the catheter 2 is also filled, making the outer walls of the catheter 2 and the heat-shrinkable catheter 20 flush, thus avoiding problems of hemolysis and thrombosis caused by height irregularities.

[0095] Multiple pits 681 are provided on the outer wall surface of the second section 68, and each pit 681 is located between a pair of adjacent proximal end support leg grooves 61. Specifically, the pits 681 are formed on the second projection 622 of the proximal end spacing projection 62. After engaging the proximal end connecting leg 131 of the stand 1 into the proximal end support leg groove 61, the proximal end collar 63 is fitted in place, and then the proximal end collar 63 is pushed down at the position of the corresponding pit 681, causing the proximal end collar 63 to deform inward and be fitted into the pit 681, thereby fixing the proximal end collar 63 to the outer wall of the proximal end bearing chamber 6. Because the outer diameter of the second portion 68 is smaller than the outer diameter of the catheter 2, as shown in Figure 2, similarly, the outer diameter of the proximal end collar 63 is approximately the same as the outer diameter of the catheter 2 and the outer diameter of the heat-shrinkable catheter 20 after heat shrinkage. This allows the proximal end collar 63 to achieve radial enveloping fixation to the proximal end connecting leg 131 and to be flush with the outer walls of the catheter 2 and the heat-shrinkable catheter 20, thereby avoiding hemolysis and thrombosis problems.

[0096] Alternatively, in another embodiment, the proximal end connection portion may be composed of a first connection portion 21 formed at the distal end of the catheter 2 described above. Similarly, in this embodiment, the thickness of the distal end outer wall of the catheter 2 is reduced to form the first connection portion 21 (proximal end connection portion). The main difference between this embodiment and the previous embodiment is the structure of the proximal end connection portion, while other structures are often the same. For example, a proximal end support leg groove 61 is formed on the outer wall of the first connection portion 21, and after fitting the proximal end connection leg 131 into the proximal end support leg groove 61, the proximal end collar 63 is fitted outside the first connection portion 21 to fix the proximal end connection leg 131 along the radial direction, and it is restrained and held within the proximal end support leg groove 61.

[0097] Furthermore, this embodiment eliminates the need to connect the catheter 2 and the stand 1 by employing a proximal end bearing chamber 6, and instead connects the catheter 2 directly to the stand 1. Another difference between this embodiment and the previous embodiment is that this embodiment only requires the installation of one proximal end collar 63, does not require the provision of a heat-shrinkable catheter 20, and has a relatively simple structure.

[0098] As described above, compared to the previous embodiment, this embodiment eliminates the proximal end bearing chamber 6, so it is necessary to replace the proximal end bearing for supporting the proximal end of the drive shaft with another structure. For example, the proximal end bearing may be provided within the proximal end of the stand 1, that is, it may be clamped and fixed by a plurality of proximal end connecting legs 131.

[0099] The ends of the drive shaft are its proximal and distal ends, respectively.

[0100] Continuing to refer to Figure 1, the stand 1 further includes a distal end connecting leg 121 located at the distal end of the stand body 11. Here, the distal end connecting leg 121 employs the same structure as the proximal end connecting leg 131. Therefore, for a detailed explanation of the specific structure of the distal end connecting leg 121 and its corresponding effects, please refer to the description of the proximal end connecting leg 131 above. No further explanation will be given for the parts that are the same, and the following explanation will mainly focus on the differences between the distal end connecting leg 121 and the proximal end connecting leg 131.

[0101] The ends of the distal end connecting leg 121 are its proximal and distal ends, respectively.

[0102] The distal end connecting legs 121 are numerous, and the numerous distal end connecting legs are spaced apart along the circumferential direction of the stand 1, and include a distal end connecting rod 124 and a distal end support rod 123 located at the proximal end of the distal end connecting rod 124. The distal end support rod 123 connects to and supports the stand body 11, and the circumferential width of the distal end support rod 123 is greater than the circumferential width of the distal end connecting rod 124. The distal end connecting rod is fixedly connected to the distal end connecting portion. The distal end support rod 123 includes a second connecting portion 1201 that is fixedly connected to the distal end connection portion, and a second outer portion 1202 located outside the proximal end of the distal end connection portion.

[0103] Furthermore, the distal end connecting rod 124 has a proximal end and a distal end, respectively, and the distal end connecting portion has two opposing ends, the two opposing ends of the distal end connecting portion are its proximal end and distal end, respectively.

[0104] Selectively, the distribution directions of the opposing ends of the distal end connection are parallel to or the same as the axial direction X.

[0105] Multiple distal end connecting legs 121 are arranged in parallel, and the spacing between adjacent distal end connecting legs 121 is equal along the circumferential direction of the stand 1. This ensures that the structure of the distal end portion of the stand 1 becomes more uniform when subjected to force, thus ensuring greater stability of the distal end portion of the stand 1 and simplifying the manufacturing process. The extension direction of the distal end connecting legs 121 is parallel to the axial direction X, facilitating connection to the distal end connection portion (e.g., distal end bearing chamber 7 and / or protective tip 5) along the axial direction X. The radial thickness of the distal end connecting legs 121 remains constant along the axial direction X. Thus, by varying the circumferential width of different parts of the distal end connecting legs 121 along the axial direction X, it is possible to adjust the rigidity of the corresponding positions of the distal end connecting legs 121, thereby making the rigidity adjustment of the distal end connecting legs 121 simple and flexible.

[0106] The distal end connecting leg 121 further includes a distal end wide portion 126 that is fixedly connected to the distal end connecting portion. The distal end wide portion 126 is connected to the distal end connecting rod 124 and forms an integrated structure. Preferably, the distal end wide portion 126 is formed at the distal end of the distal end connecting rod 124. The distal end wide portion 126 and the distal end connecting rod 124 form a roughly "T" shaped structure. This "T" shaped structure can hook onto the corresponding position of the distal end connecting portion (as described later, it is fitted into the distal end support leg groove 51), thereby achieving a fixed connection between the distal end connecting leg 121 and the distal end connecting portion in the circumferential direction and axial direction X of the stand 1.

[0107] The circumferential width of the distal end connecting rod 124 is smaller than the circumferential width of the distal end support rod 123 and also smaller than the circumferential width of the distal end wide portion 126. In this way, the circumferential width of the distal end connecting leg 121 in the axial direction X is not uniform but varies, which allows for easy and quick positioning and assembly with the distal end support leg groove, and the "T" shaped structure enables a fixed connection with the distal end connecting portion along the axial direction X.

[0108] Along the axial direction X, the axial length of the second connection portion 1201 is greater than the axial length of the distal end wide portion 126, but less than the axial length of the distal end connecting rod 124. In this way, the axial connection length (overlapping length) between the distal end connecting leg 121 and the distal end connection portion is increased to ensure the connection strength between the two, while the groove area of ​​the distal end connection portion is reduced to ensure that the structural strength of the distal end connection portion is not excessively lost, and furthermore, rigid support can be provided to the distal end cantilever structure of the stand 1.

[0109] The outer wall of the distal end connection section is provided with multiple distal end support leg grooves 51 for fitting multiple distal end connection legs 121 in a one-to-one correspondence. Each distal end support leg groove 51 includes an axial groove portion 511 extending substantially along the axial direction X, and a distal end circumferential annular groove 512 located on the far side of the axial groove portion 511 and communicating with the axial groove portion 511. The distal end connection rod 124 and the second connection portion 1201 of the distal end connection leg 121 are fitted into the axial groove portion 511, and the distal end wide portion 126 is fitted into the distal end circumferential annular groove 512.

[0110] Therefore, the difference between the distal end support leg groove 51 and the proximal end support leg groove 61 is that the groove body portion for accommodating the distal end wide portion 126 is continuous in the circumferential direction of the stand 1, forming the distal end circumferential annular groove 512, while the groove body for accommodating the proximal end wide portion 136 is part of the structure of the proximal end support leg groove 61, and does not form an annular groove structure that communicates with each other in the circumferential direction and is continuous in the circumferential direction of the stand 1.

[0111] However, these two structures can be used interchangeably and refer to each other. In other words, the structure that accommodates the distal end wide portion 126 may be part of the structure of the distal end support leg groove 51, and it is not necessary to provide a circumferentially continuous annular groove structure. Similarly, the groove body portion for accommodating the proximal end wide portion 136 may be continuous with the stand 1 in the circumferential direction and may form a proximal end circumferential annular groove.

[0112] Similarly, a distal end collar 73 is fitted outside the distal end connection portion. The distal end collar 73 is used to keep the distal end connection leg 121 within the distal end support leg groove 51 at all times by fixing the distal end connection leg 121 along the radial direction of the stand 1. The distal end collar 73 also has the function of limiting the distal end connection leg 121 from lifting up when the stand 1 is folded, and is preferably made of a metal material with higher strength.

[0113] As shown in Figures 4 and 7, the outer wall of the distal end connection portion forms a distal end spacing projection 72 between two circumferentially adjacent distal end support leg grooves 51 (specifically, axial groove portions 511). The distal end spacing projection 72 includes a fourth projection 723 located between two adjacent second connection portions 1201 and a fifth projection 722 located between two adjacent distal end connection rods 124. As described above, if the distal end wide portion 126 is housed in part of the distal end support leg groove 51 structure and there is no circumferentially continuous annular groove structure of the stand 1, the distal end spacing projection 72 further includes a sixth projection located between two adjacent distal end wide portions 126 (the attached drawing schematically shows the presence of a distal end circumferential annular groove 512, and therefore this sixth projection is absent).

[0114] Since the fifth projection 722 has the largest circumferential width compared to the fourth projection 723 and the sixth projection, the fifth projection 722 has relatively high strength and provides a highly strong positional restraining effect to the distal end "T"-shaped structure of the stand 1, ensuring that the interlocking connection formed between the distal end connecting leg 121 and the distal end connecting portion is stably maintained.

[0115] To simplify the structure of the distal end connecting leg 121 and the manufacturing process of the distal end connecting leg 121 and the distal end support leg groove 51, the circumferential widths of the distal end connecting rod 124, the distal end support rod 123, and the distal end wide section 126 are uniform. That is, the circumferential width of the distal end connecting rod 124 does not change along its extending direction, the circumferential width of the distal end support rod 123 does not change along its extending direction, and the circumferential width of the distal end wide section 126 does not change along the extending direction of the distal end connecting rod 124.

[0116] A distal end transition section 125 is provided between the distal end support rod 123 and the distal end connecting rod 124. In the direction from the proximal end to the distal end of the distal end transition section 125, the circumferential width of the distal end transition section 125 gradually decreases from a width equal to that of the distal end support rod 123 to a width equal to that of the distal end connecting rod 124, thereby avoiding stress concentration and further preventing fracture at both connection points.

[0117] The distal end transition section 125 has two opposing ends, which are its proximal and distal ends, respectively. The proximal end of the distal end transition section 125 is connected to the distal end support rod 123, and the distal end of the distal end transition section 125 is connected to the distal end connecting rod 124.

[0118] In one embodiment, the distal end connection is a distal end bearing chamber 7 connected to the distal end of the stand 1. A distal end bearing is provided inside the distal end bearing chamber 7, and the distal end of the drive shaft (specifically, the rigid shaft described later) is drilled into the distal end bearing. The aforementioned drive shaft is connected to the impeller and drives the rotation of the impeller. The distal end of the distal end bearing chamber 7 is connected to the protective tip 5. Here, the connection method between the distal end bearing chamber 7 and the distal end connecting leg 121 should refer to the connection method between the proximal end bearing chamber 6 and the proximal end connecting leg 131. The connection method between the protective tip 5 and the distal end bearing chamber 7 may be such that the proximal end of the protective tip 5 is inserted into the distal end bearing chamber 7. Specifically, refer to the known embodiment in publication no. CN216908915U, where the same parts are incorporated herein by reference and will not be described further here. In this case, the protective tip 5 is relatively thin, and a conventional "J" shaped pigtail catheter structure can be adopted.

[0119] The axial ends of the distal end bearing chamber 7 are its proximal end and distal end, respectively.

[0120] In another embodiment, the distal end connection may consist of a protective tip 5. In this embodiment, the protective tip 5 is relatively thick, has a substantially straight tip structure, and is fitted to the outside of the distal end of the distal end bearing chamber 7. In this embodiment, the structure and connection relationship between the protective tip 5 and the distal end bearing chamber 7, as well as other related structural features (e.g., hemostatic valves), can be described by reference to known embodiments of disclosure no. CN115154892A, where the same features are incorporated herein by reference and are not described further here.

[0121] Of course, in embodiments employing a straight tip-shaped protective tip 5, the distal end bearing chamber 7 is not a necessary structure and may be omitted, similar to the proximal end bearing chamber 6. Similarly, in this case, the distal end bearing may be provided within the distal end of the stand 1, that is, it may be clamped and fixed by a plurality of distal end connecting legs 121.

[0122] As shown in Figure 1, the structures of the distal end connecting leg 121 and the proximal end connecting leg 131 are exactly the same and are installed symmetrically with respect to the central plane of the stand body 11. This central plane passes through the center of the stand body 11 and is perpendicular to the axial direction X.

[0123] As shown in Figure 1, the stand body 11 has a plurality of meshes 114 distributed therein, and the meshes 114 are defined by at least two pairs of parallel straight edges 115. Specifically, the meshes 114 include two parallel first edges 116 and two parallel second edges 117. The first edges 116 and the second edges 117 are linear as a whole, and the lengths of the first edges 116 and the second edges 117 are equal. The plurality of edges 115 of the mesh 114 enclose a polygonal mesh, and the edges 115 are linear as a whole, and may be straight lines without curves. Alternatively, the edges 115 may be straight edges that allow for some degree of fine curvature and can still be intuitively considered as polygons. In embodiments of this disclosure, the edges 115 may have an overall linear structure.

[0124] Referring to Figure 2, the catheter pump of an embodiment of the present disclosure includes a power assembly (not shown) and an operating assembly. The power assembly includes a case and a motor housed within the case and having an output shaft. The operating assembly includes a catheter 2, a drive shaft inserted into the catheter 2, and a pump head. The pump head can be delivered through the catheter 2 to a desired location in the heart, for example, to pump blood into the left ventricle. The pump head includes a pump housing having a blood inlet and a blood outlet, and an impeller housed within the pump housing. The blood inlet is located at the distal end of the pump housing, and the blood outlet is located at the proximal end of the pump housing. The motor is provided at the proximal end of the catheter 2 and is connected to the catheter 2 via a coupler, and is driven by the drive shaft to rotate the impeller and pump blood.

[0125] The pump housing has two opposing ends, which are the proximal and distal ends of the pump housing.

[0126] Selectively, the distribution direction of the opposing ends of the pump housing is the same as the distribution direction of the opposing ends of stand 1.

[0127] The pump housing is connected to the distal end of the catheter 2, and the impeller is connected to the distal end of the drive shaft. The pump housing includes a casing (not shown) that restricts the flow path of blood, and a foldable stand 1 that supports and unfolds the casing, the proximal end of which is connected to the distal end of the catheter 2. This stand 1 is the stand 1 in any of the embodiments described above, and the proximal end connecting leg 131 of which is connected to the distal end of the catheter 2.

[0128] The coating covers the outside of part of the stand 1, with part of the stand 1 located inside the coating and part of the stand 1 located outside the coating. The impeller is housed within the stand 1 and located within the coating, and the stand 1 is supported by the distal end of the coating, with part of the stand 1 located inside the coating and part of the stand 1 located outside the distal end of the coating. Here, the majority of the impeller is located within the main body of the stand 1, and both ends (mainly the hubs) extend to the inlet and outlet of the stand 1.

[0129] The coating has two opposing ends, one of which is its distal end, and the distribution direction of the two opposing ends of the coating is the same as the distribution direction of the two opposing ends of the stand 1.

[0130] The coating has a cylindrical segment as its main structure and a tapered segment located at the proximal end of the cylindrical segment. One end of the cylindrical segment is its proximal end, and one end of the tapered segment is its proximal end. The proximal end of the tapered segment is located outside the catheter 2 and fixed to the outer wall of the catheter 2. The catheter 2 is connected to the proximal end of the stand 1 by a proximal end bearing chamber 6 located at its distal end, and a proximal end bearing that rotates and supports the drive shaft is provided inside the proximal end bearing chamber 6.

[0131] A distal end bearing chamber 7 is provided at the distal end of stand 1, and a distal end bearing is provided within the distal end bearing chamber 7 to rotatably support the distal end of the drive shaft. The drive shaft includes a flexible shaft inserted into catheter 2 and a rigid shaft connected to the distal end of the flexible shaft. The impeller hub is fitted onto the rigid shaft, and the proximal and distal ends of the rigid shaft are inserted into the proximal end bearing and distal end bearing, respectively. The rigid shaft and the bearings at both ends provide rigid support for the impeller in the pump housing and maintain the stability of the impeller's position in the pump housing.

[0132] Furthermore, one end of the flexible axis is its distal end, while the two ends of the rigid axis are its proximal and distal ends, respectively.

[0133] The axial ends of the proximal end bearing are its proximal and distal ends, respectively, and the axial sides of the impeller are its near and far sides, respectively. The rigid shaft is provided with a stopper member located on the near side of the proximal end bearing, which restricts the movement of the rigid shaft and the impeller toward the far side and prevents the impeller from moving toward the far side due to the reverse action of blood when it rotates and pumps blood. The rigid shaft is further provided with a position restricting member located on the near side of the stopper member, which restricts the movement of the rigid shaft and the stopper member toward the near side of the rigid shaft and prevents the release of fine particles due to the stopper member shifting and wearing down the distal end of catheter 2.

[0134] The coupler is connected to the proximal end of catheter 2, and there is a fluid channel between catheter 2 and the drive shaft. The cleaning fluid flowing through the fluid channel can provide lubrication and cooling for the rotation of the drive shaft. The coupler is provided with a cleaning fluid inlet that communicates with the fluid channel.

[0135] A flexible protective tip 5 is provided at the distal end of the distal end bearing chamber 7. Alternatively, the distal end connection portion is a protective tip connected to the distal end of the distal end connection leg, and the protective tip is flexible. The protective tip 5 is supported on the ventricular wall in a non-invasive or non-damaging manner, separating the blood inlet of the pump head from the ventricular wall, preventing the suction port of the pump head from sticking to the ventricular wall due to the reverse force of blood during pump head operation, and ensuring an effective area for pump suction.

[0136] The pump housing includes a radially folded state suitable for intervening in or transporting through the subject's vascular system, and a naturally unfolded state when the corresponding impeller is not rotating. By providing a foldable pump housing, the pump housing has a relatively small folded size and a relatively large unfolded size, satisfying both the need to reduce the subject's discomfort during intervening and transporting, facilitate intervening, and provide a high flow rate.

[0137] The pump head has an intervening configuration and an operating configuration. When the pump head is in the intervening configuration, the pump housing and impeller are radially folded, making the pump head relatively small in size and facilitating intervening in or transporting blood through the subject's vascular system. When the pump head is in the operating configuration, the pump housing and impeller are radially extended, making the pump head relatively large in size and facilitating pumping blood within the left ventricle.

[0138] The radially unfolded state of the pump housing includes the naturally unfolded state described above and the operational unfolded state when the impeller rotates, and the naturally unfolded state and the operational unfolded state are different states before and after the rotation of the impeller. Stand 1 has a straight tube structure in the radially folded state and a spindle structure in the radially unfolded state, and the axial length of stand 1 in the radially folded state is greater than the axial length in the radially unfolded state.

[0139] The polygonal mesh design of stand 1, particularly the rhomboid mesh, enables optimal folding and unfolding due to the memory properties of the nickel-titanium alloy. Depending on the interposition and operation of the pump head, stand 1 can be operationally switched between a radially folded state and a radially unfolded state.

[0140] In the radially extended state, the stand body 11 includes a substantially cylindrical main body and substantially tapered tapered sections provided at both ends of the main body in the axial direction X. The tapered section provided at the distal end of the main body is an inlet, and the distal end of the inlet is connected to a distal end connecting leg 121, which is connected to the distal end bearing chamber 7 or protective tip 5 via the distal end connecting leg 121. The tapered section provided at the proximal end of the main body is an outlet, and the proximal end of the outlet is connected to a proximal end connecting leg 131, which is connected to the proximal end bearing chamber 6 or catheter 2 via the proximal end connecting leg 131.

[0141] Furthermore, along the axial direction of the main body, both ends of the main body are its distal end and proximal end, one end of the inlet is its distal end, and one end of the outlet is its proximal end.

[0142] Stand 1 employs a laser cutting process, followed by post-processing to remove burrs and improve surface roughness. However, the impeller moves in such a way that blood collides with the surface of Stand 1 during rotation, causing it to be cut, which destroys blood cells and leads to severe hemolysis. To solve this problem, in one embodiment, a hydrophobic coating layer is provided on the surface of at least the main body of Stand 1 to improve the hemolysis situation. Preferably, the surface of the stand body 11 is provided with a hydrophobic coating layer. More preferably, the entire surface of Stand 1 is provided with a hydrophobic coating layer. The hydrophobic coating layer significantly reduces the surface friction coefficient of Stand 1, reducing frictional shear between the blood and the inner wall surface when blood flows through the stand, further reducing damage to blood cells, and thus avoiding serious hemolysis problems. Specifically, in this embodiment, a PTFE hydrophobic coating layer can be used.

[0143] As shown in Figure 5, under all other conditions equal, the normalized MIH (mechanical intravascular hemolysis) values ​​are shown for a stand without a hydrophobic coating layer (baseline) and a stand with a hydrophobic coating layer (optimized configuration) when the impeller rotates at its rated rotational speed and pumps blood. Here, the bar represents the average value of normalized MIH, and the line represents the (upper and lower) extreme values ​​of normalized MIH. Here, the extreme range of normalized MIH for the baseline stand 20511 is between approximately 0.19 and 0.88, and the average value is between approximately 0.54. The extreme range of MIH for the optimized stand is between approximately 0.1 and 0.3, and the average value is between approximately 0.2.

[0144] As can be seen from the above, after applying a hydrophobic coating layer to the stand, the MIH value, which represents the hemolysis index, decreases significantly. Specifically, the lower limit value decreases by 49%, the upper limit value decreases by 65%, and the average value decreases by 62%.

[0145] Each of the technical features of the above embodiments can be combined in any way, and for the sake of brevity, not all possible combinations of each technical feature in the above embodiments have been described. However, these combinations of technical features should be considered to fall within the scope described herein, as long as they do not contradict each other.

[0146] The above embodiments illustrate only a few embodiments of this application, and while the descriptions are more specific and detailed, they should not be understood as limiting the scope of the patent application. Those skilled in the art can make several modifications and improvements without departing from the concept of this application, and these fall within the scope of protection of this application. Therefore, the scope of protection of this patent application shall be in accordance with the claims attached. [Explanation of Symbols]

[0147] 1…Stand, 2…Catheter, 21…First connection part, 22…Stopper step, 20…Heat shrink catheter, 5…Protective tip, 51…Distal end support leg groove, 511…Axial groove portion, 512…Distal end circumferential annular groove, 6…Proximal end bearing chamber, 61…Proximal end support leg groove, 62…Proximal end spacing projection, 621…First projection portion, 622…Second projection portion, 623…Third projection portion, 63…Proximal end collar, 67…First part, 671…Through hole, 68…Second part, 681…Pit, 7…Distal end bearing chamber, 72…Distal end spacing projection, 722…Fifth projection portion, 723…Fourth projection Starting part, 73...Distal end collar, 11...Stand body, 1131...Branching structure, 114...Mesh, 115...Edge, 116...First edge, 117...Second edge, 121...Distal end connecting leg, 123...Distal end support rod, 124...Distal end connecting rod, 125...Distal end transition section, 126...Distal end wide section, 1201...Second connection section, 1202...Second outer section, 131...Proximal end connecting leg, 133...Proximal end support rod, 134...Proximal end connecting rod, 135...Proximal end transition section, 136...Proximal end wide section, 1301...First connection section, 1302...First outer section.

Claims

1. It is a catheter pump, Catheter and, The catheter has a proximal end connector that is connected to the distal end, A pump head comprising a stand and an impeller housed within the stand, wherein the impeller is used to be rotationally driven to pump blood, Here, the stand can be switched between a radially folded state and a radially extended state, and in the radially extended state, the stand includes a stand body and proximal end connecting legs located at the proximal end of the stand body, the number of proximal end connecting legs is multiple, and the multiple proximal end connecting legs are arranged at intervals along the circumferential direction of the stand. The proximal end connecting leg includes a proximal end connecting rod and a proximal end support rod located at the distal end of the proximal end connecting rod, the proximal end support rod connects to and supports the stand body, and the circumferential width of the proximal end support rod is greater than the circumferential width of the proximal end connecting rod. A catheter pump characterized in that the proximal end connecting rod is fixedly connected to the proximal end connecting portion, and the proximal end support rod includes a first connecting portion fixedly connected to the proximal end connecting portion and a first outer portion located outside the distal end of the proximal end connecting portion.

2. The catheter pump according to claim 1, wherein the proximal end connecting leg further includes a proximal end wide portion fixedly connected to the proximal end connecting portion, the circumferential width of the proximal end wide portion is greater than the circumferential width of the proximal end connecting rod, and the proximal end wide portion is located at the proximal end of the proximal end connecting rod.

3. The catheter pump according to claim 2, characterized in that the axial length of the first connecting portion is greater than the axial length of the proximal end wide portion and less than the axial length of the proximal end connecting rod.

4. The catheter pump according to claim 2, characterized in that the outer wall of the proximal end connection portion is provided with a plurality of proximal end support leg grooves for fitting a plurality of proximal end connection legs in a one-to-one correspondence, a proximal end collar is fitted outside the proximal end connection portion, and the proximal end collar is used to hold the proximal end connection legs in the proximal end support leg grooves by fixing the proximal end connection legs along the radial direction of the stand.

5. The outer wall of the proximal end connection portion forms a proximal end spacing projection between two circumferentially adjacent proximal end support leg grooves, and the proximal end spacing projection includes a first projection located between two adjacent first connection portions and a second projection located between two adjacent proximal end connection rods, wherein the circumferential width of the second projection is greater than the circumferential width of the first projection, and / or The catheter pump according to claim 4, characterized in that the material used to manufacture the proximal collar is a metallic material.

6. The circumferential width of the proximal end connecting rod remains unchanged along its extending direction, and / or The circumferential width of the proximal end support rod remains unchanged along its extending direction, and / or The catheter pump according to claim 2, characterized in that the circumferential width of the proximal end wide portion remains unchanged along the extending direction of the proximal end connecting rod.

7. A catheter pump according to claim 1, characterized in that a proximal end transition section is provided between the proximal end support rod and the proximal end connecting rod, and in the direction from the proximal end to the distal end of the proximal end transition section, the circumferential width of the proximal end transition section gradually increases from a width equal to that of the proximal end connecting rod to a width equal to that of the proximal end support rod.

8. The catheter pump according to claim 1, wherein the proximal end connection portion is a proximal end bearing chamber provided at the distal end of the catheter, a proximal end bearing is provided in the proximal end bearing chamber, a drive shaft is drilled in the proximal end bearing, and the drive shaft is connected to the impeller to drive the rotation of the impeller.

9. The stand further includes distal end connecting legs located at the distal end of the stand body, the number of distal end connecting legs being multiple, and the multiple distal end connecting legs are arranged at intervals along the circumferential direction of the stand. The distal end connecting leg includes a distal end connecting rod and a distal end support rod located at the proximal end of the distal end connecting rod, the distal end support rod connects to and supports the stand body, and the circumferential width of the distal end support rod is greater than the circumferential width of the distal end connecting rod. The catheter pump according to claim 1, characterized in that the distal end connecting rod is fixedly connected to the distal end connecting portion, and the distal end support rod includes a second connecting portion fixedly connected to the distal end connecting portion and a second outer portion located outside the proximal end of the distal end connecting portion.

10. The catheter pump according to claim 9, wherein the distal end connecting leg further includes a distal end wide portion fixedly connected to the distal end connecting portion, the circumferential width of the distal end wide portion is greater than the circumferential width of the distal end connecting rod, and the distal end wide portion is located at the distal end of the distal end connecting rod.

11. The catheter pump according to claim 10, characterized in that the axial length of the second connecting portion is greater than the axial length of the distal end wide portion and less than the axial length of the distal end connecting rod.

12. The catheter pump according to claim 10, characterized in that the outer wall of the distal end connection portion is provided with a plurality of distal end support leg grooves for fitting a plurality of distal end connection legs in a one-to-one correspondence, a distal end collar is fitted outside the distal end connection portion, and the distal end collar is used to hold the distal end connection legs in the distal end support leg grooves by fixing the distal end connection legs along the radial direction of the stand.

13. The outer wall of the distal end connection portion forms a distal end spacing projection between two circumferentially adjacent distal end support leg grooves, and the distal end spacing projection includes a fourth projection located between two adjacent second connection portions and a fifth projection located between two adjacent distal end connection rods, wherein the circumferential width of the fifth projection is greater than the circumferential width of the fourth projection, and / or The catheter pump according to claim 12, characterized in that the material used to manufacture the distal end collar is a metal material.

14. The circumferential width of the distal end connecting rod remains unchanged along its extending direction, and / or The circumferential width of the distal end support rod remains unchanged along its extending direction, and / or The catheter pump according to claim 10, characterized in that the circumferential width of the distal end wide portion remains unchanged along the extending direction of the distal end connecting rod.

15. A catheter pump according to claim 9, characterized in that a distal end transition section is provided between the distal end support rod and the distal end connecting rod, and in the direction from the distal end to the proximal end of the distal end transition section, the circumferential width of the distal end transition section gradually increases from a width equal to that of the distal end connecting rod to a width equal to that of the distal end support rod.

16. The catheter pump according to claim 9, wherein the distal end connection portion is a distal end bearing chamber connected to the distal end of the stand, a distal end bearing is provided in the distal end bearing chamber, a drive shaft is drilled in the distal end bearing, and the drive shaft is connected to an impeller to drive the rotation of the impeller.

17. The catheter pump according to claim 9, characterized in that the distal end connection portion is a protective tip connected to the distal end of the distal end connection leg, the protective tip is flexible and separates the blood inlet of the pump head from the ventricular wall.

18. The catheter pump according to claim 1, characterized in that a hydrophobic coating layer is provided on the surface of the stand.

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