CN220110269U - Catheter pump - Google Patents

Abstract

A catheter pump is disclosed that includes a motor, a catheter, and a pump head that can be delivered to a desired location of the heart through the catheter to pump blood, including a pump housing and an impeller. The pump housing has a blood inlet and a blood outlet, comprising: a stent, a covering membrane, attached to the distal end of the catheter. The support includes: a cylindrical main body part, an inlet part arranged at the axial far end of the main body part, and an outlet part arranged at the axial near end of the main body part. The coating film is covered and fixed on the radial outer part of the main body part, the inlet part is positioned on the outer side of the distal end of the coating film to form a blood inlet, the outlet part is positioned in the coating film, and the blood outlet is an opening formed on the coating film. The impeller is accommodated in the main body part and driven by the motor to rotate, so that blood is sucked into the bracket from the blood inlet, flows out from the outlet part into the coating film and finally flows out from the blood outlet, and the outer surface of the bracket is provided with a hydrophobic coating.

Description

Catheter pump

Technical Field

The present disclosure relates to the field of medical devices, and in particular to a catheter pump.

Background

Catheter pumps are classified into non-collapsible and collapsible. Among other things, collapsible catheter pumps have less trauma during intervention and thus have the benefit of more convenient and faster use.

Also, because the pump head is required to be folded in advance to reduce the size thereof and to be expanded and released after being inserted into a specific position, a corresponding structure is required to construct the pump housing portion. In view of the simplicity of the process, a prefabricated tube may be engraved or laser cut to make the carrier portion of the pump housing. After the bracket is manufactured by adopting a laser cutting process, the post-treatment is performed to remove burrs and improve the surface roughness. However, the impeller can drive the blood to collide with the surface of the bracket for cutting in the rotating process, so that blood cells are destroyed, and hemolysis is serious.

Disclosure of Invention

In view of the deficiencies of the prior art, it is an object of the present disclosure to provide a catheter pump that improves hemolysis by providing a hydrophobic coating on the surface of the stent.

In order to achieve the above object, the present utility model provides the following solutions:

a catheter pump comprising: a catheter and a pump head that can be delivered to a desired location of the heart through the catheter to pump blood, including a pump housing and an impeller. The pump housing has a blood inlet and a blood outlet, comprising: a stent, a covering membrane, attached to the distal end of the catheter. The support includes: a cylindrical main body part, an inlet part arranged at the axial far end of the main body part, and an outlet part arranged at the axial near end of the main body part. The coating film is covered and fixed on the radial outer part of the main body part, the inlet part is positioned on the outer side of the distal end of the coating film to form a blood inlet, the outlet part is positioned in the coating film, and the blood outlet is an opening formed on the coating film. The impeller is accommodated in the main body part and driven by the motor to rotate, so that blood is sucked into the bracket from the blood inlet, flows out from the outlet part into the coating film and finally flows out from the blood outlet, and the outer surface of the bracket is provided with a hydrophobic coating.

Preferably, the hydrophobic coating is a superhydrophobic coating.

Preferably, the catheter pump further comprises: a proximal connection to the distal end of the catheter. The bracket also comprises a plurality of near-end connecting legs positioned at the near end of the outlet part, and the near-end connecting legs are distributed at intervals along the circumferential direction. The proximal connecting leg includes a proximal connecting rod and a proximal support rod located distally of the proximal connecting rod. The proximal support rod is connected with and supports the outlet portion, and the circumferential width of the proximal support rod is greater than that of the proximal connecting rod. The proximal connecting rod is fixedly connected with the proximal connecting part. The proximal support rod includes: a first connecting part fixedly connected with the proximal connecting part, and a first outer part positioned at the outer side of the distal end of the proximal connecting part.

Preferably, the proximal connecting leg further comprises: a proximal wide body fixedly connected to the proximal connection portion; the proximal wide body portion is located proximal to the proximal connecting rod, and a circumferential width of the proximal wide body portion is greater than a circumferential width of the proximal connecting rod.

Preferably, the outer wall of the proximal connecting portion is provided with proximal leg grooves in which a plurality of proximal connecting legs are embedded in a one-to-one correspondence manner, and the proximal connecting portion is sleeved with a proximal collar for fixing the proximal connecting legs in the radial direction, so that the proximal connecting legs are always kept in the proximal leg grooves.

Preferably, the proximal collar is made of a metallic material.

Preferably, the catheter pump further comprises: a distal connection to the distal end of the stent. The bracket also comprises a plurality of far-end connecting legs which are positioned at the far end of the inlet part and are distributed at intervals along the circumferential direction. The distal connecting leg comprises a distal connecting rod and a distal supporting rod positioned at the proximal end of the distal connecting rod, and is connected with and supports the inlet part, and the circumferential width of the distal supporting rod is larger than that of the distal connecting rod. The distal connecting rod is fixedly connected with the distal connecting part. The distal support pole includes: a second connecting part fixedly connected with the distal connecting part, and a second outer part positioned outside the proximal end of the distal connecting part.

Preferably, the distal connecting leg further comprises: a distal wide body fixedly connected with the distal connecting part. The distal wide body portion is located distally of the distal connecting rod, and the circumferential width of the distal wide body portion is greater than the circumferential width of the distal connecting rod.

Preferably, the outer wall of the distal connecting portion is provided with distal leg grooves in which a plurality of distal connecting legs are embedded in a one-to-one correspondence manner, and the distal connecting portion is sleeved with a distal collar for radially fixing the distal connecting legs, so that the distal connecting legs are always kept in the distal leg grooves.

Preferably, the distal collar is made of a metallic material.

According to the catheter pump provided by the embodiment, the hydrophobic coating is arranged on the surface of the stent, so that the friction coefficient of the surface of the stent is greatly reduced, the friction shearing between blood and the inner wall surface of the stent when the blood flows in the stent is reduced, the damage to blood cells is further reduced, and the serious hemolysis problem is avoided.

And the connecting ring sleeve with at least partial continuous structure in the circumferential direction in the prior art is replaced by arranging a plurality of proximal connecting legs which are distributed at intervals in the circumferential direction, namely a plurality of proximal connecting legs are distributed in a scattered manner. If a circumferentially continuous connection collar structure is used (the connection collar is the proximal portion of the preformed tube), the diameter of the connection collar is the diameter of the stent after collapsing. That is, the diameter of the stent after collapsing is limited by the diameter of the proximal connecting collar, i.e., by the diameter of the preformed tube. If the diameter of the prefabricated pipe is larger, the small diameter of the folded bracket is difficult to meet, and then the requirement of the small intervention size of the pump head cannot be met. If the diameter of the prefabricated pipe is smaller, the small folding size and the intervention size of the bracket can be met, but the large unfolding diameter and the unfolding support rigidity of the bracket cannot be met at the same time. The reason is that: in order to satisfy a large deployment diameter, the amount of the tube to be cut and removed is large, and the width of the stent, particularly the stem of the main body portion, is small, resulting in a decrease in the support rigidity after deployment. In contrast, to satisfy a large deployment support rigidity, the width of the stent, particularly the stem of the main body portion, is required to be large, so that the amount of cutting removal of the tube is required not to be too large, but this in turn results in an insufficient deployment stent of the stent.

In contrast, the stent of this embodiment no longer employs a circumferentially continuous loop structure at the proximal end, but rather employs a plurality of discrete leg structures that are not connected to one another. Therefore, the diameter of the folded bracket is not limited by the diameter of the prefabricated pipe, namely, the bracket can be manufactured by adopting the prefabricated pipe with relatively larger diameter for laser cutting. Because the diameter of the selected prefabricated pipe is larger than that of the prior art, the cutting removal amount of the material is reduced in order to achieve the same unfolding diameter, the rod width of the main body part of the bracket is increased, and the supporting rigidity of the bracket is further improved. Alternatively, to achieve the same support rigidity, the amount of material cut out may be increased, the stem width of the stent body portion may be reduced, and the stent deployment diameter may be increased.

It is noted that the bracket of this embodiment is manufactured by integrally cutting a prefabricated pipe by laser. That is, in contrast to the prior art, the present embodiment uses laser cutting alone to form the main body portion and the distal connecting leg of the stent, and uses laser cutting to form the entire structure of the stent, including the main body portion, the proximal connecting leg, and the distal connecting leg. Thus, the manufacturing process of the bracket is rather simple.

The bracket manufactured by the method is in a hollow cylindrical structure (at the moment, the main body part, the proximal connecting leg, the distal connecting leg and the like are not distinguished), and the outer diameters of the axial parts are equal. And then shaping the hollow cylindrical structure (the bracket before molding for short) to obtain a final bracket structure. The method comprises the following steps: the support before forming is sleeved on the inner shaping mould, and then the outer shaping mould is sleeved outside the shaping mould (the external outline shape of the inner shaping mould and the inner cavity shape of the outer shaping mould can refer to the support shape as shown in fig. 1 or fig. 2). And then, performing a heat treatment process on the bracket before forming, heating to the phase transition temperature of a bracket material (such as nickel-titanium alloy), preserving heat for a period of time, cooling, and demolding to obtain the final bracket.

Therefore, compared with the prior art, the embodiment adopts the structure of the proximal end scattered connecting legs, and can ensure that the stent main body has larger unfolding diameter and supporting rigidity in the radial unfolding state on the premise of meeting the requirement that the stent main body is in a small size in the radial folding state. And compared with a bracket with the connecting ring sleeve at the proximal end and engraved by adopting a prefabricated pipe with a larger diameter, the bracket has the advantages of no waste, low cost and simple process.

In addition, a part (first connecting part) of the proximal support rod with larger width in the proximal connecting leg is fixedly connected with the proximal connecting part, and the first outer side part which extends to the outer side of the proximal connecting part and is in the cantilever structure can be supported, so that the proximal cantilever structure of the bracket has better supporting rigidity (the cantilever structure is prevented from being supported by the proximal connecting rod with smaller width), and the cantilever structure at the proximal end of the bracket has better supporting rigidity. In this way, the cantilever part with higher support supports the bracket main body part, so that the bracket main body part has higher support rigidity in the unfolded state.

As mentioned above, a portion of the proximal support rod (first connecting portion) is fixedly connected to the proximal connecting portion and another portion (first outer portion) extends distally from the proximal connecting portion, which also means that the proximal support rod spans the proximal connecting portion. Thus, during folding or unfolding, the junction point of the deformed section and the undeformed section of the stent is located on the proximal support rod with the distal end of the proximal connection portion as a boundary. It will be appreciated by those skilled in the art that the deformation interface is where stress concentrations and stress fatigue occur most easily, which can lead to a decrease in material stiffness. Therefore, by increasing the width of the proximal support rod, the stiffness of the proximal support rod is positively compensated, and breakage of the proximal support rod, which may be caused by repeated folding or unfolding of the stent, is avoided.

The proximal connecting rod with a narrow width mainly plays a role in axial positioning and fixed connection with the proximal connecting part, so that the proximal connecting legs are ensured to be connected with the proximal connecting part more firmly, and the connection failure between the proximal connecting legs and the proximal connecting part is prevented.

That is, the proximal connecting rod having a smaller circumferential width can flexibly and conveniently achieve connection with the proximal connecting portion. The proximal connecting part is connected with the first connecting part with larger circumferential width to provide better rigidity support for the first outer part which extends to the outer side of the distal end of the proximal connecting part and is in a cantilever structure, so that the main body part of the bracket is ensured to have better support rigidity. While the preferred support stiffness of the body portion is important for stable operation of the pump head, for example: the pump head can be prevented from being concave when the pump head is impacted laterally in the heart chamber (namely, the support is stressed laterally), so that the impeller is prevented from touching the support, and the impeller is prevented from being stopped by being forced to cause the failure of pump blood.

On the other hand, the axial length of the proximal connecting rod with smaller circumferential width is longer, so that the length of the proximal connecting leg directly connected with the proximal connecting part can be increased. And the proximal connecting part can provide a certain strength support for the proximal connecting rod, so that the connection strength of the bracket and the proximal connecting part is ensured.

In some embodiments, the wider proximal wide body is connected to the proximal connecting rod, and the outer wall of the proximal connecting portion is recessed inwardly to form a proximal leg channel for receiving the proximal connecting leg, with the proximal wide body and proximal connecting rod all embedded in the proximal leg channel. Therefore, the proximal wide body part, the proximal connecting rod and the proximal connecting part form a hook-type physical connection structure, the hook-type physical connection structure can resist axial pulling between the catheter and the bracket continuously, and particularly in the scene of folding the pump head from the proximal end, the connection relationship between the catheter and the bracket can be stably maintained under the action of the sustainable axial pulling resistance, so that disconnection is avoided.

In some embodiments, the strength of the connection between the proximal connecting leg and the proximal connecting portion is ensured by increasing the length of the proximal connecting rod, which is smaller in width, on the one hand, by increasing the axial connection length (overlap length) of the two. On the other hand, the grooving area of the near-end connecting part can be reduced, the structural strength of the near-end connecting part is ensured not to be excessively lost, and further structural support is provided for the near-end cantilever structure.

On the other hand, the distal connecting leg formed at the distal end of the bracket adopts the same (mirror symmetry) structural design as the proximal connecting leg, so that the distal cantilever structure of the bracket also has better supporting rigidity. In this way, the stent is also supported from the distal end with a strong stiffness. The support has better rigidity supporting function at both ends by matching with the same structure of the proximal connecting legs, so that the main body part of the support has better supporting rigidity in the unfolding state.

The distal connecting leg and the proximal connecting leg are designed to have the same or similar structure, so that substantially the same technical effects can be achieved.

Drawings

FIG. 1 is a schematic view of a structure of a stent provided in one embodiment of the present disclosure;

FIG. 2 is a front view of FIG. 1;

FIG. 3 is a schematic diagram of a catheter pump provided in one embodiment of the present disclosure;

FIG. 4 is a schematic view of the structure of the proximal connector shown in FIG. 3;

FIG. 5 is a cross-sectional view of FIG. 4;

FIG. 6 is a schematic illustration of the structure of the junction of the proximal bearing chamber and the proximal connecting leg provided by one embodiment of the present disclosure;

FIG. 7 is a schematic view of the structure of the junction of the distal bearing chamber and the distal connecting leg provided by one embodiment of the present disclosure;

FIG. 8 is a cross-sectional view of FIG. 7;

FIG. 9 is an enlarged view of a portion of FIG. 5;

FIG. 10 is a graph of experimental data for a stent provided with a hydrophobic coating according to one embodiment of the present disclosure;

FIG. 11 is a schematic structural view of a proximal bearing chamber of an embodiment of the present disclosure;

FIG. 12 is a schematic structural view of a distal bearing chamber and protective tip assembly of an embodiment of the present disclosure;

fig. 13 is a schematic structural view of a catheter and a first connection portion at a distal end thereof according to an embodiment of the present disclosure.

Reference numerals illustrate:

1. A bracket; 2. a conduit; 21. a first connection portion; 22. a stop step; 20. a heat shrinkage tube; 3. a drive shaft; 31. a flexible shaft; 32. a hard shaft; 4. an impeller; 5. protecting the tip; 51. a distal leg slot; 511. an axial slot portion; 512. a distal circumferential ring groove; 6. a proximal bearing chamber; 61. a proximal leg channel; 62. the proximal end is spaced apart from the boss; 621. a first convex portion; 622. a second convex portion; 623. a third convex portion; 63. a proximal collar; 64. a proximal bearing; 65. a stopper; 66. a limiting piece; 67. a first portion; 671. a through hole; 68. a second portion; 681. pit; 7. a distal bearing chamber; 72. distal spacing bosses; 722. a fifth convex portion; 723. a fourth convex portion; 73. a distal collar; 74. a distal bearing; 11. a holder main body; 111. a main body portion; 112. an inlet portion; 113. an outlet portion; 1131. a bifurcated structure; 114. a mesh; 115. edge edges; 116. a first edge; 117. a second edge; 121. a distal connecting leg; 123. a distal support rod; 124. a distal connecting rod; 125. a distal transition portion; 126. a distal wide body; 1201. a second connection portion; 1202. a second outer portion; 131. a proximal connecting leg; 133. a proximal support rod; 134. a proximal connecting rod; 135. a proximal transition; 136. a proximal wide body; 1301. a first connection portion; 1302. a first outer portion; x, axial direction.

Detailed Description

The present utility model will be described in detail below with reference to specific embodiments shown in the drawings. These embodiments are not intended to limit the utility model and structural, methodological, or functional modifications of these embodiments by one of ordinary skill in the art are included within the scope of the present disclosure.

The terms "proximal", "distal" and "anterior", "posterior" as used in this disclosure are relative to a clinician manipulating the catheter pump of this embodiment. The terms "proximal", "posterior" and "anterior" refer to portions relatively closer to the clinician, and the terms "distal" and "anterior" refer to portions relatively farther from the clinician. For example, the extracorporeal portion is proximal and posterior and the intervening intracorporeal portion is distal and anterior.

It is to be understood that the terms "near," "far," "back," "front," and these orientations are defined for convenience in the description. However, catheter pumps may be used in many orientations and positions, and thus these terms of expressing relative positional relationships are not limiting and absolute. For example, the above definition of each direction is only for the convenience of illustrating the technical solution of the present utility model, and is not limited to the direction of the catheter pump of the present utility model in other scenarios including, but not limited to, product testing, transportation and manufacturing, etc., which may cause the inversion or position change thereof. In the present utility model, the above definitions should follow the above-mentioned explicit definitions and definitions, if they are defined otherwise.

In the present utility model, the terms "connected," "connected," and the like should be construed broadly unless otherwise specifically indicated and defined. For example, the device can be fixedly connected, detachably connected, movably connected or integrated; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In addition, the technical features of the different embodiments of the present utility model described below may be combined with each other as long as they do not collide with each other.

The catheter pump of the embodiments of the present disclosure is used to achieve a partial pumping function of the heart. In a scenario suitable for left ventricular assist, a catheter pump pumps blood from the left ventricle into the main artery, providing support for blood circulation, reducing the workload of the subject's heart, or providing additional sustained pumping power support when the heart is not sufficiently pumping. Of course, the catheter pump may also be used to intervene as desired in other target locations of the subject, such as the right ventricle, blood vessels, or other organ interiors, depending on the interventional procedure.

Referring to fig. 1 and 2, a catheter pump of an embodiment of the present disclosure includes a catheter 2, a proximal connection, and a pump head. The proximal connection is connected to the distal end of the catheter 2. The pump head comprises a bracket 1 and an impeller 4 accommodated in the bracket 1, and the impeller 4 can be driven to rotate to pump blood. The stent 1 is operable to switch between a radially collapsed state and a radially expanded state. In the radially expanded state, the stent 1 includes a stent body 11, proximal connecting legs 131 at the proximal end of the stent body 11. The proximal connecting legs 131 are plural in number and are circumferentially spaced apart. The proximal connecting leg 131 is of unitary construction with the stent body 11.

The proximal connecting leg 131 includes a proximal connecting rod 134 and a proximal support rod 133 located distally of the proximal connecting rod 134, the proximal connecting rod 134 being integrally constructed with the proximal support rod 133. The proximal support bar 133 connects and supports the stent body 11, and the circumferential width of the proximal support bar 133 is greater than the circumferential width of the proximal connecting bar 134. The proximal connecting rod 134 is fixedly connected to the proximal connecting portion, and the proximal support rod 133 includes a first connecting portion 1301 fixedly connected to the proximal connecting portion and a first outer portion 1302 located distally outwardly of the proximal connecting portion.

The plurality of proximal connecting legs 131 are arranged in parallel and the intervals between the adjacent proximal connecting legs 131 are equal, so that the structure of the proximal portion of the bracket 1 is more uniform when being stressed, the structure of the proximal portion of the bracket 1 is more stable, and the manufacturing process can be simplified. The proximal connecting leg 131 extends in a direction parallel to the axial direction X so as to facilitate connection with a proximal connection (e.g. catheter 2 or proximal bearing housing 6). The radial thickness of the proximal connecting leg 131 is kept constant in the axial direction X, so that the rigidity adjustment of the corresponding position of the proximal connecting leg 131 can be achieved by the circumferential widths of different portions of the proximal connecting leg 131, and the rigidity adjustment of the proximal connecting leg 131 is simple and flexible.

In addition, the radial thickness of the proximal connecting leg 131 is also equal to that of the stent body 11 and the distal connecting leg 121. That is, the thickness of the solid structure of the stent 1 is the same, uniform at all positions in the axial direction. Thus, the bracket 1 can be manufactured by adopting a prefabricated pipe with uniform wall thickness through laser cutting, and the manufacturing process of the bracket 1 is simple. And the thickness of the solid structure at all positions of the bracket 1 is the same, which means that the wall thickness of the bracket 1 after folding is uniform, thereby ensuring the uniform size of the whole pump head after folding.

The proximal connecting leg 131 further includes a proximal wide body 136 fixedly connected to the proximal connecting portion, the proximal wide body 136 being connected to the proximal connecting bar 134 and being integrally constructed, preferably the proximal wide body 136 being formed at a proximal end of the proximal connecting bar 134. The proximal connecting rod 134 extends along the axial direction X, the proximal wide body 136 extends along the circumferential direction, the proximal wide body 136 and the proximal wide body are arranged approximately vertically, and the circumferential width of the proximal wide body 136 is larger than that of the proximal connecting rod 134, so that the proximal wide body 136 and the proximal connecting rod 134 form an approximately T-shaped structure, and the T-shaped structure can be hooked at a corresponding position of a proximal connecting part (embedded in the proximal leg groove 61 as described below) to realize the fixed connection of the proximal connecting leg 131 and the proximal connecting part along the circumferential direction and the axial direction X.

The circumferential width of the proximal connecting rod 134 is smaller than the circumferential width of the proximal support rod 133 and also smaller than the circumferential width of the proximal wide body 136. In this way, the circumferential width of the proximal connecting leg 131 in the axial direction X is varied rather than uniform, so that the positioning and assembly with the proximal leg groove 61 can be conveniently and rapidly achieved, and the fixed connection with the proximal connecting portion in the axial direction X can be achieved by means of the above-described "T" -shaped structure.

The axial length of the first connection portion 1301 is greater than the axial length of the proximal wide body 136, but less than the axial length of the proximal connecting rod 134. That is, the portion overlapping or connecting with the proximal connecting portion, the proximal connecting bar 134 is the longest in length and the proximal wide body 136 is the shortest. By lifting the length of the proximal connecting rod 134 having a smaller width (i.e., the length of the proximal connecting rod 134 having the smallest width is maximized), on the one hand, the axial connection length (overlapping length) of the proximal connecting leg 131 and the proximal connecting portion is lifted to secure the connection strength of the two. On the other hand, the grooving area of the near-end connecting part can be reduced, the structural strength of the near-end connecting part is ensured not to be excessively lost, and further, the rigidity support is provided for the near-end cantilever structure.

As shown in fig. 1, the first connection portion 1301 is linear and extends in the axial direction X, and is disposed on the outer wall of the proximal connection portion together with the proximal connection bar 134. In the radially collapsed state, the first outer portion 1302 is linear and extends in the axial direction X. In the radially expanded state of the stent 1, the first outer section 1302 is curved and the distance from the first outer section 1302 to the central axis of the stent 1 increases gradually from the proximal end to the distal end. Wherein the central axis is an axis passing through the center of the bracket 1 and perpendicular to the axial direction X. That is, in the radially expanded state, the first outer portion 1302 is bent distally from the first connection portion 1301 to a bifurcated structure 1131, the bifurcated structure 1131 being the proximal junction of the ridges forming the mesh in the outlet portion 113 described below. The first outer portion 1302 may provide rigid support to the main body portion of the stent 1 in the radially expanded state.

As shown in fig. 6, the outer wall of the proximal connection part is provided with proximal leg grooves 61 into which a plurality of proximal connection legs 131 are inserted in one-to-one correspondence, and the shape of the proximal leg grooves 61 is matched with the associated shape of the proximal connection legs 131. The proximal connection portion is sleeved with a proximal collar 63, and the proximal collar 63 is used to radially secure the proximal connection leg 131 such that the proximal connection leg 131 is always retained within the proximal leg channel 61. The proximal leg groove 61 is for receiving the proximal wide body 136, the proximal connecting rod 134 and the first connecting portion 1301.

Since the sheath tube applies an axial force to the deployed stent 1 when the pump head is collapsed, the axial force tends to expand the end of the stent 1 radially outward due to the lever principle. The radially outward expansion of the proximal portion of the stent 1 weakens the fixed connection between the proximal and proximal connection portions of the stent 1, further exacerbating the likelihood of disconnection of the two.

If the support adopts the connecting secondary pipe structure in the prior art, as the connecting secondary pipe structure is of a continuous structure in the circumferential direction, any part of the tubular connecting secondary pipe in the circumferential direction and the adjacent part are involved with each other, so that the radial expansion existing in the folding of the pump head can be effectively counteracted and eliminated. Thus, the fixed connection of the stent to the proximal connection may be better maintained.

In contrast, the stent 1 of the present embodiment adopts a circumferentially dispersed leg structure for the proximal portion to be connected to the proximal connection portion, and the dispersed legs do not generate a force that involves each other as in the case of connecting the sub-tubes. Thus, when the pump head is folded, the possibility that the support leg expands radially outwards and is separated from the proximal end connecting part (specifically, the T-shaped structure at the proximal end of the support leg is tilted from the support leg groove) is greatly improved, and the fixed connection relationship between the support 1 and the proximal end connecting part is further affected.

Therefore, the proximal collar 63 is sleeved outside the proximal connecting portion in this embodiment, so as to resist the radially outward expansion force of the proximal portion of the proximal connecting leg 131, avoid the radially outward expansion of the proximal connecting leg 131 and separate from the proximal connecting portion, ensure that the T-shaped structure formed by the proximal portion of the proximal connecting leg 131 is always maintained in the proximal leg groove 61, and further maintain the fixed connection therebetween for a long time.

Further, the conventional proximal collar mostly adopts a heat shrink tube, which is mainly from the viewpoint of simple process. But the heat shrink tubing is inherently a plastic tubing that is weak and difficult to resist the outward tilting force of the proximal connecting leg 131. In practice, the problem has also been found that the proximal collar made with heat shrink tubing is penetrated by the proximal end of the proximal connecting leg 131. In view of this, the proximal collar 63 of the present embodiment is made of a metal material with higher strength, such as copper or copper-aluminum alloy, so as to avoid the above-mentioned problems, and further, the proximal connection leg 131 can be more reliably fixed and restrained in the proximal leg groove 61 in the radial direction.

As shown in fig. 6 and 11, the outer wall of the proximal connection forms a proximal spacing boss 62 between two circumferentially adjacent proximal leg slots 61. The portion 622 of the proximal end spacing protrusion 62 between the proximal end connecting rods 134 has a circumferential width greater than the circumferential width of the proximal end connecting rods 134, the portion 623 between the proximal end wide bodies 136 has a circumferential width less than the circumferential width of the proximal end wide bodies 136, and the portion 621 between the first connection portions 1301 has a circumferential width less than the circumferential width of the first connection portions 1301.

Specifically, the proximal-end spacing protrusion 62 includes a first protrusion portion 621 located between two adjacent first connection portions 1301, a second protrusion portion 622 located between two adjacent proximal connection bars 134, and a third protrusion portion 623 located between two adjacent proximal wide body portions 136. Essentially, the width of the proximal end spacing boss 62 in the axial direction X also varies, except that the circumferential width of the portion at the location corresponding to the proximal connecting rod 134, i.e., the second boss portion 622, is greatest, greater than the circumferential width of the first boss portion 621, and greater than the circumferential width of the third boss portion 623. Because the "T" shaped structure formed by the proximal wide body 136 and the proximal connecting rod 134 forms a hooked connection with the proximal end of the second protruding portion 622 of the proximal end spacing protruding portion 62, the circumferential width of the second protruding portion 622 is maximized, so that the second protruding portion 622 has relatively large strength, thereby providing a high-strength limiting effect for the proximal "T" shaped structure of the stent 1, avoiding the problem that the proximal end spacing protruding portion 62 collapses in material at the proximal end of the second protruding portion 622 when the stent 1 applies a distally directed axial force to the proximal connecting portion during folding, and ensuring stable maintenance of the hooked connection.

The circumferential width of the proximal connecting rod 134 is uniform, the circumferential width of the proximal support rod 133 is also uniform, and the circumferential width of the proximal wide body 136 is also uniform. That is, the circumferential width of the proximal connecting rod 134 remains unchanged in the axial direction X, the circumferential width of the proximal support rod 133 remains unchanged in the axial direction X, and the circumferential width of the proximal wide body 136 remains unchanged in the axial direction X. In this way, the structure of the proximal connecting leg 131 and, above all, the process of making the proximal connecting leg 131 and the proximal leg groove 61 that mates therewith can be simplified as much as possible.

The reason for achieving the above effects is that: the proximal connecting leg 131 itself already includes a plurality of different width portions (i.e., the proximal connecting rod 134, the proximal support rod 133 and the proximal wide body 136), if the respective different portions are designed to be varied in width, for example, the proximal connecting rod 134/the proximal support rod 133 are designed to be gradually wider or narrower along the proximal to distal ends, etc., this greatly increases the complexity of the process for manufacturing the proximal connecting leg 131, and such a complicated structural design of the proximal connecting leg 131 does not significantly increase the performance of other aspects such as the connection strength with the proximal connecting portion, but rather causes the width of the proximal leg groove 61 to be correspondingly varied in cooperation therewith, thereby complicating the formation of the proximal leg groove 61. The proximal connecting rod 134, the proximal support rod 133 and the proximal wide body 136 have uniform widths, which can avoid the above-mentioned problems.

A proximal transition 135 is provided between the proximal support rod 133 and the proximal connecting rod 134, and the circumferential width of the proximal transition 135 gradually increases from equal to the proximal connecting rod 134 to equal to the proximal support rod 133 in the proximal-to-distal direction. The gradual increase may be linear or exponential, and may be represented by a sloped transition and a cambered transition, respectively, in the configuration of the proximal transition 135. Providing the proximal transition 135 may allow the connected proximal support rod 133 and proximal connecting rod 134 to exhibit a gradual width change process, rather than abrupt changes, which may avoid stress concentration at the connection between the proximal support rod 133 and proximal connecting rod 134 due to abrupt width changes, thereby avoiding breakage at the connection therebetween.

In one embodiment, as shown in fig. 6, the proximal connection is a proximal bearing housing 6 provided at the distal end of the catheter 2. As shown in fig. 5, a proximal bearing 64 is provided in the proximal bearing chamber 6, and the drive shaft 3 (specifically, a hard shaft 32 described below) is inserted into the proximal bearing 64. The driving shaft 3 is connected with the impeller 4 for driving the impeller 4 to rotate. The proximal leg groove 61 is provided on the outer wall surface of the distal end of the proximal bearing housing 6, and the proximal collar 63 is fitted over the outer wall surface of the proximal bearing housing 6 where the proximal leg groove 61 is provided.

As shown in fig. 9 and 13, the distal end outer wall of the catheter 2 is reduced in diameter to form the first connection portion 21, and specifically, the outer wall surface of the distal end section of the catheter 2 is reduced in thickness to form the first connection portion 21. A stop step 22 is formed between the first connection portion 21 and the distal portion of the catheter 2 adjacent thereto for providing a stop limit for the proximal bearing housing 6, facilitating positioning and mounting of the two.

As shown in fig. 11, the proximal bearing housing 6 is a stepped structure having a first portion 67 at the proximal end and a second portion 68 at the distal end, the first portion 67 and the second portion 68 having equal inner diameters, but the first portion 67 has a smaller outer diameter than the second portion 68. The outer diameter of the second portion 68 is smaller than that of the catheter 2, the first portion 67 is sleeved outside the first connecting portion 21, and the proximal leg groove 61 is formed in the outer wall surface of the second portion 68.

The first portion 67 is provided with a through hole 671 penetrating the inner and outer surfaces thereof. When the proximal bearing housing 6 and the catheter 2 are assembled, the heat shrink tube 20 is first sleeved outside the first portion 67 of the proximal bearing housing 6, and then the first portion 67 of the proximal bearing housing 6 is sleeved outside the first connecting portion 21 of the catheter 2. Subsequently, a heat shrinkage process is performed on the heat shrinkage tube 20, and the heat shrinkage tube 20 material is melted and flowed into the through hole 671 to be adhered to the outer wall of the first connection portion 21 of the catheter 2. At the same time, the heat-shrunk inner wall material of the heat shrink tubing 20 will bond with the outer wall of the first portion 67, thereby securing the proximal bearing housing 6 to the catheter tube 2. Preferably, the material of the heat shrinkage tube 20 and the material of the catheter 2 are the same, so that the heat shrinkage tube 20 and the catheter 2 have the same molecular structure, and the bonding strength between the melted heat shrinkage tube 20 and the material of the catheter 2 is improved, and the fixing connection effect of the proximal bearing chamber 6 and the catheter 2 is further improved.

The first portion 67 is formed by reducing the thickness of the outer wall of the distal end of the catheter 2, with the addition of the first connecting portion 21, due to the smaller outer diameter. Thus, after the first portion 67 of the proximal bearing housing 6 is sleeved onto the first connector 21, the outer wall of the first portion 67 is not flush with the distal outer wall of the catheter 2, specifically the outer wall of the first portion 67 is lower than the distal outer wall of the catheter 2.

The outer diameter of the heat-shrinkable tube 20 after heat shrinkage is approximately equal to the outer diameter of the catheter tube 2. Therefore, the heat shrinkage tube 20 is sleeved outside the first part 67, so that the fixed connection between the proximal bearing chamber 6 and the catheter 2 is realized, and the height difference between the first part 67 and the outer wall of the distal end of the catheter 2 can be filled, so that the catheter 2 is flush with the outer wall of the heat shrinkage tube 20, and the problems of hemolysis and thrombosis caused by the presence of uneven height are avoided.

The outer wall surface of the second portion 68 is provided with a plurality of recesses 681, and the plurality of recesses 681 are respectively located between the plurality of proximal leg grooves 61. Specifically, the recess 681 is formed on the second convex portion 622 of the proximal-end spacing boss 62. After the proximal connecting leg 131 of the bracket 1 is clamped into the proximal leg groove 61, the proximal sleeve 63 is sleeved, then the proximal sleeve 63 is pressed down at the position corresponding to the concave pit 681, and the proximal sleeve 63 is deformed inwards to be embedded into the concave pit 681, so that the fixation of the proximal sleeve 63 on the outer wall of the proximal bearing chamber 6 is realized. Because the outer diameter of the second portion 68 is smaller than the outer diameter of the catheter 2, as shown in fig. 3, the outer diameter of the proximal collar 63 is also approximately the same as the outer diameter of the catheter 2 and the heat-shrinkable tube 20 after heat shrinkage, so that the proximal collar 63 is flush with the outer walls of the catheter 2 and the heat-shrinkable tube 20 while achieving radial wrap-around fixation of the proximal connection legs 131, avoiding problems of hemolysis and thrombosis.

Alternatively, in another embodiment, the proximal connection may be formed by the first connection 21 formed at the distal end of the catheter 2 as described above. Also in this embodiment, the distal outer wall of the catheter 2 is thinned to form a first connection portion 21 (proximal connection portion). The present embodiment differs from the previous embodiment mainly in that the structure as the proximal connection is different and the other structures are mostly identical. For example, the outer wall of the first connecting portion 21 forms a proximal leg groove 61, the proximal connecting leg 131 is fitted into the proximal leg groove 61, and a proximal collar 63 is fitted around the first connecting portion 21 to radially fix the proximal connecting leg 131 so as to be restrained and held in the proximal leg groove 61.

Furthermore, since the present embodiment eliminates the use of the proximal bearing housing 6 to connect the catheter 2 to the stent 1, the catheter 2 is directly connected to the stent 1. Therefore, another difference between this embodiment and the previous embodiment is that this embodiment only has to provide a proximal collar 63, and the heat shrink tubing 20 is not needed, which is relatively simple in structure.

As mentioned above, the proximal bearing chamber 6 is eliminated as compared to the previous embodiment. Accordingly, the proximal bearing 64 for supporting the proximal end of the drive shaft may need to be alternatively provided by other structures. For example, the proximal bearing 64 may be provided in the proximal end of the stent 1, i.e. held in place by a plurality of proximal connecting legs 131.

With continued reference to fig. 1 and 2, the stent 1 further comprises distal connecting legs 121 at the distal end of the stent body 11. Wherein the distal connecting leg 121 adopts the same structure as the proximal connecting leg 131. Therefore, for the specific structure of the distal connecting leg 121 and the corresponding description of the effect, reference should be made to the description of the proximal connecting leg 131, and the same will not be repeated, and the following mainly focuses on the portion of the distal connecting leg 121 different from the proximal connecting leg 131.

The distal connecting legs 121 are provided in a plurality and are circumferentially spaced apart, and include a distal connecting rod 124 and a distal support rod 123 positioned proximally of the distal connecting rod 124. The distal support bar 123 connects to and supports the stent body 11 with a circumferential width greater than that of the distal connecting bar 124, and includes a second connecting portion 1201 fixedly connected to the distal connecting portion and a second outer portion 1202 located proximally and outwardly of the distal connecting portion.

The plurality of distal connecting legs 121 are arranged in parallel and the intervals between the adjacent distal connecting legs 121 are equal, so that the structure of the distal part of the bracket 1 can be more uniform when being stressed, the structure of the distal part of the bracket 1 is more stable, and the manufacturing process can be simplified. The distal connecting leg 121 extends in a direction parallel to the axial direction X, thereby facilitating connection with a distal connecting portion (e.g., the distal bearing housing 7 or the protective tip 5) along the axial direction X. The radial thickness of the distal connecting leg 121 remains unchanged in the axial direction X, so that the rigidity adjustment of the corresponding position of the distal connecting leg 121 can be realized by the circumferential widths of different parts of the distal connecting leg 121, and the rigidity adjustment of the distal connecting leg 121 is simple and flexible.

Distal connecting leg 121 further includes a distal wide body 126 fixedly attached to the distal connecting portion, distal wide body 126 being attached to and integrally constructed with distal connecting rod 124, preferably distal wide body 126 being formed at the distal end of distal connecting rod 124. The distal wide body 126 and the distal connecting rod 124 form a generally "T" shaped structure that can be hooked in a corresponding location of the distal connecting portion (embedded in the distal leg groove 51 as described below) to achieve a secure connection of the distal connecting leg 121 to the distal connecting portion in the circumferential and axial directions X.

The circumferential width of distal connecting rod 124 is less than the circumferential width of distal support rod 123 and also less than the circumferential width of distal wide body 126. In this way, the circumferential width of the distal connecting leg 121 along the axial direction X is varied rather than uniform, so that the positioning and assembly with the distal leg groove can be conveniently and rapidly realized, and the fixed connection with the distal connecting portion along the axial direction X can be realized by means of the above-mentioned T-shaped structure.

The axial length of the second connecting portion 1201 is greater than the axial length of the distal wide body 126, but less than the axial length of the distal connecting rod 124. In this way, on the one hand, the axial connection length (overlapping length) of the distal connection leg 121 and the distal connection portion is increased, so as to ensure the connection strength of the two. On the other hand, the grooving area of the far-end connecting part can be reduced, the structural strength of the far-end connecting part is ensured not to be excessively lost, and further, the rigidity support is provided for the far-end cantilever structure.

The outer wall of the distal connecting portion is provided with distal leg grooves 51 into which the plurality of distal connecting legs 121 are fitted one by one, and the distal leg grooves 51 include an axial groove portion 511 extending substantially in the axial direction X, and a distal circumferential ring groove 512 located distally of the axial groove portion 511 and communicating with the axial groove portion 511. The distal connecting rod 124 and the second connecting portion 1201 of the distal connecting leg 121 are embedded in the axial groove portion 511, and the distal wide body 126 is embedded in the distal circumferential groove 512.

Thus, the distal leg groove 51 differs from the proximal leg groove 61 in that the groove body portion for accommodating the distal wide body 126 is circumferentially continuous, forming a distal circumferential ring groove 512. The channel housing the proximal wide portion 136 is part of the proximal leg channel 61 structure and does not circumferentially interconnect to form a circumferentially continuous ring channel structure.

However, it should be noted that these two structures can be used interchangeably and interchangeably. That is, the receiving distal wide body 126 may be part of the distal leg groove 51 structure and need not provide a circumferentially continuous ring groove structure. Likewise, the portion of the channel for receiving the proximal wide body 136 may be circumferentially continuous, forming a proximal circumferential groove.

Similarly, the distal connection portion is sleeved with a distal collar 73 for radially securing the distal connection leg 121 such that the distal connection leg 121 is always retained within the distal leg groove 51. The distal collar 73 also has the function of limiting the tilting of the distal connecting legs 121 when the stent 1 is folded, and is preferably made of a metallic material having higher strength.

As shown in fig. 7 and 12, the outer wall of the distal connection forms a distal spacing protrusion 72 between circumferentially adjacent two distal leg grooves 51 (specifically, axial groove portions 511), the distal spacing protrusion 72 including a fourth protrusion 723 between adjacent two second connection portions 1201, a fifth protrusion 722 between adjacent two distal connection bars 124. As described above, when the receiving distal wide body 126 is part of the distal leg groove 51 structure, and there is no continuous groove structure in the circumferential direction, the distal spacing tab 72 further includes a sixth tab portion (the drawing is shown schematically with the distal circumferential groove 512 present, and thus the sixth tab portion is not present) located between adjacent two distal wide body 126.

The circumferential width of the fifth protruding portion 722 is maximized, so that the fifth protruding portion 722 has relatively high strength, thereby providing a high-strength limit function for the distal T-shaped structure of the stent 1, and ensuring stable maintenance of the hook-type connection formed between the distal connecting leg 121 and the distal connecting portion.

The respective circumferential widths of the distal connecting rod 124, the distal support rod 123 and the distal wide body 126 are uniform to simplify the structure of the distal connecting leg 121 and to simplify the manufacturing process of the distal connecting leg 121 and the distal leg groove 51.

A distal transition portion 125 is provided between the distal support rod 123 and the distal connecting rod 124, and in the direction from the proximal end to the distal end, the circumferential width of the distal transition portion 125 gradually decreases from being equal to the distal support rod 123 to being equal to the distal connecting rod 124, so as to avoid stress concentration and further avoid fracture at the connecting portion of the two.

In one embodiment, the distal connection is a distal bearing housing 7 connected to the distal end of the stent 1. As shown in fig. 5, a distal bearing 74 is provided in the distal bearing chamber 7, and the distal end of the drive shaft 3 (specifically, a hard shaft 32 described below) is inserted into the distal bearing 74, and the distal end of the distal bearing chamber 7 is connected to the protection tip 5. The connection between the distal bearing chamber 7 and the distal connecting leg 121 may be referred to as a connection between the proximal bearing chamber 6 and the proximal connecting leg 131. The connection between the protecting tip 5 and the distal bearing chamber 7 may be that the proximal end of the protecting tip 5 is inserted into the distal bearing chamber 7, and the same is referred to in the known embodiment of CN216908915U, and is not repeated herein. The protective tip 5 is now relatively thin and may be constructed using a conventional "J" shaped Pigtail (Pigtail) configuration.

In another embodiment, the distal connection may be constituted by a protective tip 5. In this embodiment, the guard tips 5 are thicker, generally straight-headed Tip-like structures, and fit distally outwardly of the distal bearing chamber 7. Regarding the structure and connection relationship between the protection tip 5 and its distal bearing chamber 7, and other structural features related thereto, such as a scheme of a hemostatic valve, in this embodiment, reference may be made to the known embodiment provided by publication No. CN115154892a, which is incorporated herein by reference, and will not be repeated here.

Of course, in embodiments employing a straight-headed Tip-like structure for the guard Tip 5, the distal bearing chamber 7 is not a necessary structure and may be omitted as with the proximal bearing chamber 6. Then, as before, the distal bearing 74 may be provided within the distal end of the stent 1, i.e., held in place by a plurality of distal connecting legs 121.

As shown in connection with fig. 1 and 2, the distal connecting leg 121 and the proximal connecting leg 131 are identical in structure and are symmetrically disposed about the center plane of the holder body 11. The center plane passes through the center of the holder body 11 and is perpendicular to the axial direction X.

As shown in fig. 1, the stent body 11 is provided with a plurality of meshes 114, and the meshes 114 are defined by at least two pairs of parallel linear edges 115. Specifically, the mesh 114 includes two parallel first edges 116 and two parallel second edges 117. The first edge 116 and the second edge 117 are linear as a whole, and the lengths of the first edge 116 and the second edge 117 are equal. The plurality of edges 115 of the mesh 114 enclose a polygonal mesh, and the edges 115 are entirely linear, which may be linear without bending. Alternatively, the edges 115 may be straight edges that allow some slight curvature and still be intuitively considered as polygons. In the embodiments of the present disclosure, the edges 115 need to be of generally rectilinear configuration.

Referring to fig. 3-5, a catheter pump of an embodiment of the present disclosure includes a power assembly (not shown) and a work assembly. The power assembly includes a housing and a motor received within the housing and having an output shaft. The working assembly comprises a conduit 2, a drive shaft 3 penetrating the conduit 2, and a pump head. The pump head can be delivered to a desired location of the heart, such as the left ventricle for pumping blood through the catheter 2, and includes a pump housing having a blood inlet and a blood outlet, and an impeller 4 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 arranged at the proximal end of the catheter 2, is connected with the catheter 2 through a coupler, and drives the impeller 4 to rotate and pump blood through the driving shaft 3.

The pump housing is connected to the distal end of the catheter 2 and the impeller 4 is connected to the distal end of the drive shaft 3. The pump housing comprises a cover (not shown) defining a blood flow path and a foldable stent 1 supporting the deployed cover, the proximal end of the stent 1 being connected to the distal end of a catheter 2. The stent 1 is the stent 1 of any of the embodiments described above, and the proximal connecting legs 131 of the stent 1 are connected to the distal end of the catheter 2.

The coating is covered outside part of the bracket 1, part of the bracket 1 is arranged in the coating, and the other part is arranged outside the coating. Specifically, the coating is covered and fixed on the radially outer portion of the main body portion 111, the inlet portion 112 is located on the outer side of the distal end of the coating to form a blood inlet, the outlet portion 113 is located inside the coating, and the blood outlet is an opening formed on the coating. When the impeller 4 is driven to pump blood in a rotating manner, the blood is sucked into the stent 1 through the blood inlet, flows out of the stent 1 through the outlet 113 into the coating, and finally flows out of the coating through the blood outlet.

The impeller 4 is accommodated in the bracket 1 and is positioned in the tectorial membrane, the bracket 1 is supported at the distal end of the tectorial membrane, part of the bracket 1 is positioned at the outer side of the distal end of the tectorial membrane, and the other part of the bracket 1 is positioned in the tectorial membrane. Of these, the impeller 4 is mostly located in the main body portion 111 of the stand 1, with both ends (mainly hubs) extending into the inlet portion 112 and the outlet portion 113.

The coating has a cylindrical section as a main body structure and a tapered section at a proximal end of the cylindrical section. The proximal end of the conical section is arranged outside the catheter 2 and is fixed with the outer wall of the catheter 2. The catheter 2 is connected to the proximal end of the stent 1 by a proximal bearing housing 6 at its distal end, the proximal bearing housing 6 being provided with a proximal bearing for rotatably supporting the drive shaft 3.

The distal end of the bracket 1 is provided with a distal end bearing chamber 7, and a distal end bearing for rotatably supporting the distal end of the driving shaft 3 is arranged in the distal end bearing chamber 7. The drive shaft 3 comprises a flexible shaft 31 penetrating the catheter 2 and a hard shaft 32 connected to the distal end of the flexible shaft 31, the hub of the impeller 4 is sleeved on the hard shaft 32, and the proximal end and the distal end of the hard shaft 32 are respectively penetrated in a proximal bearing and a distal bearing. By means of the hard shaft 32 and bearings at both ends, a rigid support is provided for the impeller 4 in the pump housing, keeping the position of the impeller 4 stable in the pump housing.

The hard shaft 32 is provided with a stop 65 located proximal to the proximal bearing 64 for limiting distal movement of the hard shaft 32 and impeller 4 to prevent distal movement of the impeller 4 due to the reverse action of blood during the rotational pumping of blood. The hard shaft 32 is further provided with a limiting member 66 located at the proximal side of the stopping member 65, and the limiting member is used for limiting the movement of the hard shaft 32 and the stopping member 65 in the proximal direction, so as to prevent the stopping member 65 from being biased against the distal end of the catheter 2 to release particulates.

The coupler is connected to the proximal end of the catheter 2, with a fluid flow path between the catheter 2 and the drive shaft 3, in which fluid flow path the flushing fluid can provide lubrication and cooling for the rotation of the drive shaft 3. The coupler is provided with a flushing fluid input interface which is communicated with the liquid runner.

The distal end of the distal end bearing chamber 7 is provided with a flexible protection tip 5, and the protection tip 5 is supported on the inner wall of the ventricle in a non-invasive or non-invasive way, separates the blood inlet of the pump head from the inner wall of the ventricle, avoids the suction inlet of the pump head from being attached to the inner wall of the ventricle due to the reaction force of blood in the working process of the pump head, and ensures the effective area of pumping.

The pump housing comprises a radially collapsed state adapted to be inserted into or transported in the subject's vasculature, corresponding to a natural deployed state when the impeller 4 is not rotated. By arranging the foldable pump shell, the pump shell has smaller folding size and larger unfolding size, so that the requirements of relieving pain of a subject and easy intervention in the intervention/transportation process and providing large flow are met.

The pump head has an interposed configuration and an operating configuration. With the pump head in the access configuration, the pump housing and impeller 4 are in a radially collapsed state so that the pump head is accessed or delivered in the vasculature of the subject with a smaller size. In the operating configuration of the pump head, the pump housing and the impeller 4 are in a radially expanded state so that the pump head pumps blood in the left ventricle in larger dimensions.

The radially expanded state of the pump casing includes the above-described natural expanded state and the operational expanded state when the impeller 4 rotates, and the natural expanded state and the operational expanded state are different states before and after the rotation of the impeller 4. The support 1 is in a straight pipe structure in a radial folding state and in a spindle structure in a radial unfolding state, and the axial length of the support 1 in the radial folding state is larger than that in the radial unfolding state.

The polygonal mesh, in particular diamond mesh, design of the bracket 1 can realize better folding and unfolding by means of the memory property of nickel-titanium alloy. The stent 1 is operable to switch between a radially collapsed state and a radially expanded state, corresponding to the intervention configuration of the pump head and to the working configuration.

In the radially expanded state, the holder body 11 includes a substantially cylindrical body portion 111 and substantially conical cone portions provided at both ends of the body portion 111 in the axial direction X. The taper portion provided at the distal end of the main body portion 111 is an inlet portion 112, and the distal end of the inlet portion 112 is connected to a distal connecting leg 121, and the distal bearing chamber 7 or the protection tip 5 is connected through the distal connecting leg 121. The tapered portion provided at the proximal end of the main body 111 is an outlet portion 113, and the proximal end of the outlet portion 113 is connected to a proximal connecting leg 131, and the proximal bearing chamber 6 or the catheter 2 is connected to the proximal connecting leg 131.

The stent 1 adopts a laser cutting process to carry out post-treatment to remove burrs and improve surface roughness, and the impeller 4 drives blood to collide with the surface of the stent 1 for cutting in the rotating process of the impeller, so that blood cells are damaged, and hemolysis is serious. To solve this problem, in one embodiment, a hydrophobic coating is provided at least on the surface of the main body portion 111 of the stent 1 to improve hemolysis. Preferably, the surface of the stent body 11 is provided with a hydrophobic coating. More preferably, the entire surface of the stent 1 is provided with a hydrophobic coating. The hydrophobic coating can greatly reduce the friction coefficient of the surface of the bracket 1, reduce friction shearing between the blood and the inner wall surface of the bracket when the blood flows in the bracket, further reduce damage to blood cells and avoid serious hemolysis. Specifically, the hydrophobic coating of this example may be a PTFE hydrophobic coating of the brand AD911E supplied by the Asahi Kasei Corp.

As shown in fig. 10, normalized MIH (mechanical intravascular hemolysis) values for an uncoated stent (Baseline) and a stent coated with a hydrophobic coating (optimized) are shown for impeller rotation pumping at nominal operating speeds, all other conditions being equal. Wherein the bars represent the average value of normalized MIH and the lines represent the (upper and lower) extremum of normalized MIH. The range of the extremum of the normalized MIH of the reference frame 20511 is about 0.19 to 0.88, and the average value is about 0.54. The MIH of the optimized cradle 20511 has an extremum ranging from about 0.1 to about 0.3 and an average value of about 0.2.

From this, it can be seen that the MIH value, which characterizes the hemolysis index, is greatly reduced after the stent is coated with the hydrophobic coating. Specifically, the lower extreme value is reduced by 49%, the upper extreme value is reduced by 65%, and the average value is reduced by 62%.

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

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

Claims (10)

1. A catheter pump, comprising:

a motor;

a conduit;

a pump head, which pumps blood through the catheter to a desired location of the heart, including a pump housing and an impeller; wherein,

The pump housing has a blood inlet and a blood outlet, comprising: a stent, a cover attached to the distal end of the catheter; the bracket comprises: a cylindrical main body part, an inlet part arranged at the axial distal end of the main body part, and an outlet part arranged at the axial proximal end of the main body part; the cover film is covered and fixed on the radial outer part of the main body part, the inlet part is positioned on the outer side of the distal end of the cover film to form the blood inlet, the outlet part is positioned in the cover film, and the blood outlet is an opening formed on the cover film;

the impeller is accommodated in the main body part and driven by the motor to rotate so as to suck blood into the bracket from the blood inlet, then flow out from the outlet part into the coating film and finally flow out from the blood outlet;

the outer surface of the bracket is provided with a hydrophobic coating.

2. The catheter pump of claim 1, wherein the hydrophobic coating is a superhydrophobic coating.

3. The catheter pump of claim 1, wherein,

the catheter pump further comprises: a proximal connection to the distal end of the catheter;

the bracket further comprises: a proximal connecting leg connected to a proximal end of the outlet portion; the number of the proximal connecting legs is multiple, and the proximal connecting legs are distributed at intervals along the circumferential direction; the proximal connecting leg includes: a proximal connecting rod, a proximal support rod located distally of the proximal connecting rod; the proximal support rod is connected with and supports the outlet part, and the circumferential width of the proximal support rod is larger than that of the proximal connecting rod;

The proximal connecting rod is fixedly connected with the proximal connecting part; the proximal support rod includes: the first connecting part is fixedly connected with the proximal connecting part, and the first outer side part is positioned on the outer side of the distal end of the proximal connecting part.

4. The catheter pump of claim 3, wherein the proximal connection leg further comprises: a proximal wide body fixedly connected to the proximal connection portion; the proximal wide body is located at the proximal end of the proximal connecting rod, and the circumferential width of the proximal wide body is greater than that of the proximal connecting rod.

5. The catheter pump of claim 3, wherein the outer wall of the proximal connection portion is provided with proximal leg grooves into which a plurality of the proximal connection legs are inserted in one-to-one correspondence, the proximal connection portion is sleeved with a proximal collar, and the proximal collar is used for radially fixing the proximal connection legs so that the proximal connection legs are always kept in the proximal leg grooves.

6. The catheter pump of claim 5, wherein the proximal collar is made of a metallic material.

7. The catheter pump of claim 1, wherein,

the catheter pump further comprises: a distal connection to the distal end of the stent;

The bracket further comprises: a distal connecting leg located distally of the inlet section; the number of the far-end connecting legs is multiple, and the far-end connecting legs are distributed at intervals along the circumferential direction; the distal connecting leg includes: the far-end support rod is positioned at the near end of the far-end connecting rod, the far-end support rod is connected with and supports the inlet part, and the circumferential width of the far-end support rod is larger than that of the far-end connecting rod;

the distal connecting rod is fixedly connected with the distal connecting part; the distal support bar includes: the second connecting part is fixedly connected with the distal connecting part, and the second outer side part is positioned at the outer side of the proximal end of the distal connecting part.

8. The catheter pump of claim 7, wherein the distal connection leg further comprises: a distal wide body fixedly connected to the distal connecting portion; the distal wide body is located at the distal end of the distal connecting rod, and the circumferential width of the distal wide body is greater than the circumferential width of the distal connecting rod.

9. The catheter pump of claim 7, wherein the outer wall of the distal connection portion is provided with distal leg grooves into which a plurality of the distal connection legs are inserted in one-to-one correspondence, the distal connection portion is sleeved with a distal collar for radially fixing the distal connection legs so that the distal connection legs are always held in the distal leg grooves.

10. The catheter pump of claim 9, wherein the distal collar is made of a metallic material.