CN217960999U

CN217960999U - Catheter pump and pump shell thereof

Info

Publication number: CN217960999U
Application number: CN202220416000.XU
Authority: CN
Inventors: 付建新; 曾广智
Original assignee: Magassist Inc
Current assignee: Xinqing Medical Suzhou Co ltd
Priority date: 2021-10-29
Filing date: 2022-02-25
Publication date: 2022-12-06
Anticipated expiration: 2032-02-25
Also published as: WO2023070515A1; CN219251398U; CN114225213A; CN219251391U; CN219251397U; CN114225213B; CN219251396U; CN116059524A; CN217960998U

Abstract

A catheter pump and a pump shell thereof are disclosed, wherein the pump shell comprises a bracket capable of accommodating an impeller and a film for limiting a blood flow channel, and the film covers part of the bracket. The pump housing has a radially collapsed state adapted for intervention or delivery within a subject's vasculature and a naturally expanded state corresponding to when the impeller is not rotating. Under the natural expansion state, the support comprises a main body part which is approximately cylindrical, and conical parts which are approximately conical and are arranged at two ends of the main body part in the axial direction, and a transition part is arranged between the conical parts and the main body part. When the support is switched from the radial folding state to the natural unfolding state, the strain of the transition part is larger than that of the main body part and larger than that of the conical part.

Description

Catheter pump and pump shell thereof

Technical Field

The present disclosure relates to the field of medical devices, in particular to a device for cardiac assist, more particularly to a catheter pump and its pump housing.

Background

An interventional catheter pump device (blood pump for short) can pump blood. Taking left ventricle assistance as an example, in the prior art, a pump of an interventional catheter pump device is generally disposed in a left ventricle of a subject, an impeller of the pump is driven to rotate by a flexible shaft, and the flexible shaft is driven by a motor to transmit power to the pump.

To ensure stable contraction and expansion, existing catheter pumps are capable of being inserted into a patient's blood vessel and expanded after insertion. During compression and expansion, the rotor (e.g., impeller) and the housing are often deformed accordingly, which presents problems: it is desirable to maintain the pump clearance, i.e., the spacing gap between the radially outer end of the impeller and the inner wall of the casing, at a minimum and constant level in order to optimize the pump performance.

The pump body of the catheter pump needs to be folded into the sheath tube before being inserted into a body, and is moved out and unfolded at a desired position in the body, and the sheath tube needs to be retracted again when the pump body is moved out of the body, so that the pump body of the catheter pump needs excellent folding and restoring capabilities, the shape of the pump shell can be stably maintained after the pump body is unfolded, and the pump effect is prevented from being adversely affected due to the fact that the pump shell cannot stably maintain the shape.

Disclosure of Invention

In view of the above problems, it is an object of the present disclosure to provide a catheter pump and a pump housing thereof which facilitate stable maintenance of a pump gap.

It is yet another object of the present disclosure to provide a collapsible catheter pump and pump housing therefor.

In order to achieve at least one of the above purposes, the present disclosure adopts the following technical solutions:

a pump casing for a catheter pump, the pump casing comprising a support capable of receiving an impeller, a membrane defining a blood flow passage, the membrane covering a portion of the support; the pump housing has a radially collapsed state adapted for intervention or delivery within a subject's vasculature and a natural expanded state when the corresponding impeller is not rotating;

in a naturally expanded state, the holder includes a substantially cylindrical main body portion, and substantially tapered portions provided at both axial ends of the main body portion; a transition part is arranged between the conical part and the main body part; wherein, when the stent is switched from the radially collapsed state to the naturally expanded state, the strain of the transition portion is greater than the strain of the main body portion, and the strain of the transition portion is greater than the strain of the tapered portion.

Preferably, the tapered portion at the distal end of the main body portion is an inlet portion, and the tapered portion at the proximal end of the main body portion is an outlet portion; a far-end transition part is arranged between the inlet part and the main body part, and a near-end transition part is arranged between the main body part and the outlet part; the transition portion comprises a plurality of transition ribs which are distributed discontinuously in the circumferential direction.

Preferably, a plurality of polygonal supporting meshes are distributed on the main body part; the strain of the main body part includes the strain of the longest edge of the support mesh; the degree of variation of the length of the edge between the two end points of the longest edge; the strain of the transition portion includes a degree of change in length of the transition rib.

Preferably, the transition portion assumes an arcuate configuration in the naturally deployed state and assumes a substantially linear configuration or a slightly curved configuration having a curvature less than the arcuate configuration in the radially collapsed state.

Preferably, the transition portion has a curvature in the radially collapsed state that is less than a curvature in the naturally expanded state.

Preferably, when the stent is switched from the radially collapsed state to the naturally expanded state, the change degree of the axial length of the stent is greater than the strain of the transition portion.

Preferably, the transition portion includes a smooth transition outer surface extending from the body portion to the tapered portion.

Preferably, the transition part is of a round structure; the curvature radius of the transition part is 0.8mm-1.5mm; the extension length of the transition part is 1mm-2mm, and further the extension length of the transition part is 1.2mm-1.7mm.

Preferably, the main body portion includes a plurality of serrated rings arranged in an axial direction, the serrated rings having front crests directed toward the inlet portion and rear crests directed toward the outlet portion; the front tooth top of one of the two adjacent sawtooth rings is arranged opposite to the rear tooth top of the other sawtooth ring along the axial direction;

the stent has a front stretch rib extending from a forward most crest to a distal end of the stent and a rear stretch rib extending from a rearward most crest to a proximal end of the stent; the front stretching rib forms meshes of the inlet part around the front stretching rib; the rear stretching rib surrounding forms meshes of the outlet part;

wherein portions of the front stretch ribs form transition ribs of the distal transition; portions of the rear stretch riblets form transition riblets of the proximal transition.

A catheter pump in which, in a catheter pump,

a motor;

a conduit;

the driving shaft penetrates through the catheter, and the near end of the driving shaft is in transmission connection with the output shaft of the motor;

a pump body deliverable through the catheter to a desired location of the heart to pump blood, comprising: a pump casing according to any one of claims 1 to 9, an impeller housed in the pump casing; the pump housing is connected to the distal end of the catheter and the impeller is connected to the distal end of the drive shaft.

The pump shell of the present disclosure can smoothly fold the two connected portions (the main body portion and the tapered portion) by forming the maximum strain at the transition portion, thereby ensuring the smoothness of folding the entire support. In addition, the maximum strain occurs at the transition part, not at the inlet part, the outlet part or the main body part, so that the structure of the main functional part of the stent (the main body part is used for surrounding the impeller, an impeller rotating space is formed, and the pump gap, the inlet part and the outlet part are respectively used for ensuring the areas of blood inflow and blood outflow) can be kept stable, and the problems that the undesired structure is unstable due to the excessive strain of the inlet part, the outlet part and the main body part which are the main functional parts of the stent, the pump gap is unstable, the areas of blood inflow or blood outflow are unstable, and the like can be avoided.

Drawings

FIG. 1 is a perspective view of a catheter pump configuration provided by one embodiment of the present disclosure;

FIG. 2 is a schematic cross-sectional view of the pump body of FIG. 1;

FIG. 3 is a cross-sectional profile view of the stent of FIG. 2 in a naturally expanded state;

FIG. 4 is a perspective view of the support structure of FIG. 3;

FIG. 5 is an enlarged view of a portion of FIG. 4;

FIG. 6 is another enlarged view of a portion of FIG. 4;

FIG. 7 is a schematic view of the support mesh of FIG. 4 in a naturally expanded state;

FIG. 8 is a schematic view of FIG. 7 in a radially collapsed state;

FIG. 9 is a schematic diagram comparing different states of the transition portion of FIG. 7;

FIG. 10 is a longitudinal cross-sectional view of the simulated radial collapsed condition of FIG. 4;

fig. 11 is a longitudinal sectional view of the naturally expanded state of fig. 10.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present disclosure, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings in the embodiments of the present disclosure, and it is obvious that the described embodiments are only a part of the embodiments of the present disclosure, and not all the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.

It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

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

The terms "proximal", "distal" and "anterior", "posterior" are used in this disclosure with respect to a clinician operating an interventional catheter pump. The terms "proximal" and "posterior" refer to portions that are relatively close to the clinician, and the terms "distal" and "anterior" refer to portions that are relatively far from the clinician. For example, the extracorporeal portion is proximal and posterior, and the interventional intracorporeal portion is distal and anterior.

The catheter pump disclosed by the embodiment of the disclosure is used for assisting in cardiac failure, and can pump blood to the heart to realize partial blood pumping function of the heart. In a scenario suitable for left ventricular assist, a catheter pump pumps blood from the left ventricle into the aorta, providing support for blood circulation, reducing the workload of the subject's heart, or providing additional continuous pump hemodynamic support when the heart pump capacity is insufficient.

Of course, the catheter pump may also be introduced into other target locations of the subject, such as the right ventricle, blood vessels, or other organs, as desired, by interventional procedures.

Referring to fig. 1 to 11, a catheter pump according to an embodiment of the present disclosure includes a power assembly 1 and a working assembly. The power assembly 1 comprises a shell and a motor which is contained in the shell and provided with an output shaft, and the working assembly comprises a guide pipe 3, a driving shaft 30 which is arranged in the guide pipe 3 in a penetrating mode and a pump body 4. The pump body 4 is deliverable through a catheter 3 to a desired location of the heart, such as the left ventricle for pumping blood, and includes a pump housing having a blood inlet 106 and a blood outlet 105, and an impeller 10 housed within the pump housing. The motor is provided at the proximal end of the catheter 3, is connected to the catheter 3 via the coupler 2, and drives the impeller 10 to pump blood rotationally via the drive shaft 30.

The pump housing is connected to the distal end of the catheter and the impeller 10 is connected to the distal end of the drive shaft 30. The pump housing includes at least a membrane 5 defining a blood flow passage, and further includes a stent 6 for supporting the deployed membrane 5, a proximal end of the stent 6 being connected to a distal end of the catheter 3. As shown in fig. 4, the proximal end of the holder 6 is provided with a secondary connection pipe 43, and the secondary connection pipe 43 is provided with a connection hole (the connection hole is shown in fig. 10 and 11) constituting a female buckle, thereby forming a mechanical connection structure of a snap-fit type with the catheter 3.

The covering film 5 covers part of the stent 6, and the stent 6 is arranged partially in the covering film 5 and partially outside the covering film 5. Specifically, the impeller 10 is housed within the stent 6 and positioned within the stent graft 5, the stent 6 is supported at the distal end of the stent graft 5, a portion of the stent 6 is positioned outside the distal end of the stent graft 5, and another portion of the stent 6 is positioned within the stent graft 5.

The coating film 5 has a cylindrical section as a main structure and a conical section positioned at the proximal end of the cylindrical section, and the proximal end of the conical section is sleeved outside the catheter 3 and fixed with the outer wall of the catheter 3. The catheter 3 is connected to the proximal end of the stent 6 by a proximal bearing chamber at its distal end, in which proximal bearing chamber a proximal bearing is provided for rotatably supporting the drive shaft 30.

The distal end of the bracket 6 is provided with a distal bearing chamber 7, and a distal bearing for rotatably supporting the distal end of the drive shaft 30 is provided in the distal bearing chamber 7. The support 6 maintains the spacing of the proximal and distal bearing chambers 7, thereby providing stable rotational support for the drive shaft 30. The driving shaft 30 includes a flexible shaft penetrating the catheter 3 and a hard shaft connected to a distal end of the flexible shaft, a hub of the impeller 10 is sleeved on the hard shaft, and a proximal end and a distal end of the hard shaft are respectively penetrated in the proximal bearing and the distal bearing. The hard shaft and the bearings at the two ends provide stable strength support for the impeller 10 in the pump shell, and the position of the impeller 10 in the pump shell is kept stable.

The coupler 2 is connected to the proximal end of the catheter 3, and a fluid flow path is provided between the catheter 3 and the drive shaft 30, whereby infusion fluid introduced through the fluid flow path can provide lubrication for the rotation of the drive shaft 30 and avoid frictional heating of the rotation. The coupler 2 is provided with a perfusate input part 20 communicated with the liquid flow channel, and the perfusate input part 20 is communicated with the liquid flow channel. The distal end of the coupler 2 is provided with a retaining sleeve 260 for the catheter 3 to pass through, and the retaining sleeve 260 may serve to fix the catheter 3.

The distal end of distal end bearing room 7 is connected with does not have wound support piece 8, does not have wound support piece 8 and is a flexible pipe body structure, it is circular-arc or the flexible arch of coiling form to represent to the tip, thereby it supports on the heart ventricle inner wall with the mode of not having wound or not damaged to not have wound support piece 8, separate the blood import 106 and the ventricle inner wall of the pump body 4, avoid the pump body 4 make the suction inlet laminating of the pump body 4 on the heart ventricle inner wall because the reaction force of blood in the course of the work, guarantee the effective area of pumping.

The pump housing includes a radially collapsed state adapted for intervention or delivery within a subject's vasculature, corresponding to a naturally expanded state when the impeller 10 is not rotating. The pump shell which can be folded is arranged, so that the pump shell has smaller folded size and larger unfolded size, the pain of a testee is relieved in the process of intervention/delivery, the intervention is easy, and the requirement of large flow is met.

The pump body 4 has an interposed configuration as well as an operating configuration. In the intervention configuration of the pump body 4, the pump housing and the impeller 10 are radially collapsed, so that the pump body 4 is inserted into or delivered in the vascular system of the subject at a first outer diameter dimension. In the corresponding operating configuration of the pump body 4, the pump casing and the impeller 10 are in a radially expanded condition, so that the pump body 4 pumps blood at a desired location with a second outer diameter dimension greater than the first outer diameter dimension. Accordingly, the radially expanded state of the pump casing includes a natural expanded state in which the impeller 10 is stationary and a working expanded state in which the impeller 10 is rotated. And the stent 6 has a first axial length in a radially collapsed state and a second axial length in a naturally expanded state, the first axial length being greater than the second axial length. Wherein the length of the stent 6 varies to a greater extent than the strain of the transition portion 48.

In the naturally expanded state, the holder 6 includes a substantially cylindrical main body portion 40 and substantially tapered portions (41, 42) provided at both ends of the main body portion 40 in the axial direction. Transition portions 48 (48 a, 48 b) are provided between the tapered portions (41, 42) and the main body portion 40. When the stent 6 is switched from the radially collapsed state to the naturally expanded state, the strain of the transition portion 48 is larger than the strain of the main body portion 40 and larger than the strain of the tapered portions (41, 42).

Referring to fig. 10 and fig. 11, the inventors have analyzed through simulation studies that the mechanism of different deformation occurring at different parts may be: as the connection portion connecting the front end inlet portion, the rear end outlet portion 42 and the main body portion 40 at the middle position, two transition portions 48 at both axial sides (the proximal end transition portion 48 and the distal end transition portion 48 may generate multi-compound deformation in at least three directions of radial direction, axial direction and circumferential direction during the folding process, but the inlet portion 41, the outlet portion 42 and the main body portion 40 may generally generate deformation in only two directions of axial direction and radial direction, or the circumferential deformation degree is low, and the main body portion 40, the inlet portion 41 and the outlet portion 42 are used as the core portion of the whole stent 6, the deformation is passive, so the transition portion 48 between the main body portion 40 and the cone portions (41, 42) generates the largest strain.

The transition portion 48 is a transition between the axial extension and the oblique extension, and includes, on the one hand, deformation of the main body portion 40 and, on the other hand, deformation of the tapered portions (41, 42), which corresponds to deformation of the transition portion 48 being substantially composite deformation of the main body portion 40 and the tapered portions (41, 42), and thereby maximum strain is formed at that portion.

In addition, the deformation of the entire structure of the main body portion 40 and the tapered portions (41, 42) is mainly based on a change in which the frame gap of the bracket 6 itself is reduced and increased, and the rate of deformation of the frame edge of the bracket 6 itself is small. However, the transition portion 48 is also crucial in the deformation of the entire structure not only due to the change in the frame gap but also due to its own shape change (self strain), so as to transition the entire deformation between the main body portion 40 and the tapered portions (41, 42) and smoothly complete the folding of the stent 6.

In the above description, the pump casing is folded by means of external constraint, and the pump casing is self-unfolded after the constraint is removed. The application of the external restraint described above is accomplished by a folded sheath (not shown) that is slidably fitted over the catheter 3. When the folding sheath pipe moves forwards outside the catheter 3, the pump shell can be integrally contained in the folding sheath pipe, so that the pump shell is forcibly folded. When the folding sheath pipe moves backwards, the constraint of the folding sheath pipe is removed, the radial constraint on the pump shell disappears, the pump shell automatically expands under the action of the memory characteristic of the bracket 6, and the impeller 10 automatically expands under the action of the released energy storage. In the deployed state, the outer diameter of the impeller 10 is smaller than the inner diameter of the pump casing. Thus, the radially outer end (i.e., the tip) of the impeller 10 is spaced from the inner wall of the pump casing (specifically, the inner wall of the mount), which is the pump clearance. The presence of the pump gap allows the impeller 10 to rotate unimpeded without wall impingement.

Furthermore, it is desirable that the pump gap size be of a small value and maintained for hydrodynamic considerations. In the present embodiment, the outer diameter of the impeller 10 is slightly smaller than the inner diameter of the holder 6 as the holder 6, so that the pump clearance is as small as possible while satisfying that the impeller 10 rotates without hitting the wall. The main means for maintaining the pump gap is the supporting strength provided by the holder 6, which can resist the action of the blood back pressure without excessive deformation, and thus the shape of the pump case is maintained stable, and the pump gap is also maintained stably.

The pump casing according to the present disclosure can smoothly fold the two portions (the main body portion 40 and the tapered portions (41, 42)) connected to the transition portion 48 by forming the maximum strain in the transition portion, thereby ensuring the smoothness of folding the entire support 6. In addition, the maximum strain occurs at the transition portion 48, instead of the inlet portion 41, the outlet portion 42 or the main body portion 40, so that the structure of the main functional portion of the stent 6 (the main body portion 40 forms a rotation space of the impeller 10 to surround the impeller 10 and maintain the pump gap; the inlet portion 41 and the outlet portion 42 respectively ensure the areas of blood intake and bleeding) is kept stable, and the problems that the inlet portion 41, the outlet portion 42 and the main body portion 40 which are the main functional portion of the stent 6 are unstable due to the excessive strain, and the pump gap is unstable, and the areas of blood intake and bleeding are unstable are avoided.

The tapered portions (41, 42) of the holder 6 include: a substantially conical inlet portion 41 at the distal end, and a substantially conical outlet portion 42 at the proximal end. A proximal transition 48b is provided between the body portion 40 and the outlet portion 42 and a distal transition 48a is provided between the body portion 40 and the inlet portion 41. The proximal transition 48b and the distal transition 48a are substantially symmetrically located at the axial ends of the main body portion 40. The axial length (projected length on the central axis) or extension (length extending from one end to the other end in the axial direction) of the transition portion 48 is much smaller than the axial length or extension of the main body portion 40, the inlet portion 41 or the outlet portion 42, wherein the axial length of the main body portion 40 is substantially the same as the extension.

Wherein, under the natural unfolding state, the axial length of the main body part 40 is 30mm-40mm, the outer diameter of the main body is 6.5mm-8.5mm, the axial length of the conical parts (41, 42) is 5.5 mm-7.5 mm, more specifically, the axial length of the conical parts (41, 42) is 6mm-7mm, and the taper is 10 degrees-50 degrees. The thickness (radial width) of the edge of the bracket 6 is 0.1mm-0.3mm.

In the naturally unfolded state, the main body portion 40 is cylindrical, and the transition portion 48 is a curved transition structure without a tip structure, so as to avoid breaking during the forced folding process. Meanwhile, the covering film or human tissue is prevented from being damaged in the rotating process. The stent 6 is self-restored to be unfolded until the natural unfolding state after the external force is removed (the sheath tube is removed).

In this embodiment, the transition portion 48 includes a smooth transition outer surface 4811 extending from the main body portion 40 to the tapered portions (41, 42) for ease of folding and avoiding damage to the covering film and body tissue. Further, the transition portion 48 is of a rounded configuration with a radius of curvature R1 of 0.8mm to 1.5mm, and an arc length (extension of the transition portion 48) of 1mm to 2mm, further between 1.2mm to 1.7mm, and further between 1.411mm to 1.656 mm.

The transition portion 48 has a proximal transition point (transition point with the outlet portion 42) and a distal transition point (transition point with the inlet portion 41). The extension of the transition portion 48 is the extension of the transition portion 48 between the proximal and distal transition points, i.e., the extension of the transition rib 4811 described below.

It is noted that any numerical value in this disclosure includes all values from the lower value to the upper value that are incremented by one unit, and that there may be an interval of at least two units between any lower value and any higher value.

For example, the illustrated radius of curvature R1 of the transition portion 48 is 0.8mm to 1.5mm, preferably 0.9mm to 1.4mm, more preferably 1.0mm to 1.3mm, and even more preferably 1.1mm to 1.2mm, for the purpose of illustrating equivalents such as 0.85mm, 0.95mm, 1.05mm, 1.15mm, 1.25mm, 1.35mm, 1.45mm that are not expressly enumerated above.

As described above, the example range of 0.1 as the interval unit cannot exclude the increase of the interval in an appropriate unit, for example, a numerical unit such as 0.01, 0.02, 0.03, 0.04, 0.05, etc. These are only examples of what is intended to be explicitly recited, and all possible combinations of numerical values between the lowest value and the highest value that are explicitly recited in the specification in a similar manner are to be considered.

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

Other definitions of numerical ranges appearing herein may be found in reference to the above description and are not repeated here.

In keeping with the above description, the transition portion 48 is rounded on both the inside and outside thereof, and accordingly, the transition portion 48 further includes a smooth transition inner surface extending from the main body portion 40 to the tapered portions (41, 42). The transition portion 48 is a circular arc edge (transition rib 4811) with a certain length and arranged at intervals in the circumferential direction. By arranging the rounded structure at the transition part 48, the main body part 40 and the tapered parts (41, 42) are in smooth transition, so that the problem of breakage of the support 6 is avoided when the pump body is forcibly folded by external force, and the smooth folding of the support 6 is ensured.

In the present embodiment, the transition portion 48 is intermittently arranged in the circumferential direction (may also be referred to as an intermittent arrangement), and includes intermittently distributed transition ribs 4811 in the circumferential direction (intermittent distribution). The two adjacent transition ribs 4811 have a circumferential spacing space therebetween to provide a circumferential contraction space when collapsed, the curved configuration thereof is deformed, the curvature is gradually reduced, a substantially linear configuration or a slightly curved configuration is formed, and the stent 6 is formed in a straight tube state as shown in fig. 10.

Wherein the transition ribs 4811 are circumferentially intermittently distributed. The transition portion 48 (transition rib 4811) assumes an arcuate configuration in its naturally expanded state and a generally linear configuration or slightly curved configuration having a curvature less than the arcuate configuration in its radially collapsed state. In the process of switching the stent 6 from the radially collapsed state to the naturally expanded state, the curvature radius R of the transition portion 48 (transition rib 4811) decreases, and the curvature gradually increases. Accordingly, the transition portion 48 has a smaller curvature, a larger radius of curvature R2, in the radially collapsed state than in the naturally expanded state. In a longitudinal section, the transition 48 is curved, as shown in fig. 9. The main body portion 40 and the tapered portions (41, 42) are straight lines on both sides of the transition portion 48.

In the present embodiment, the bracket 6 is an integrally formed structure made of a memory alloy material. More specifically, the bracket 6 is a hot-press integrated structure. The polygonal meshes, particularly the diamond meshes, of the stent 6 can be folded better, and meanwhile, the stent can be unfolded by means of the memory property of the nickel-titanium alloy. The mesh of the stent 6 has mesh edges.

Tapered portions (41, 42) provided at the distal end of the body portion 40 serve as an inlet portion 41, and the distal end of the inlet portion 41 is further provided with a front connecting portion through which the distal end bearing chamber is connected. Tapered portions (41, 42) provided at the proximal end of the body portion 40 serve as an outlet portion 42, and a connection sub-pipe is further provided at the proximal end of the outlet portion 42, and the catheter 2 is connected thereto via a connection sub-pipe 43.

Specifically, the mesh of the main body 40 is a plurality of supporting mesh 50, and the supporting mesh 50 is a closed polygonal hole to form a stable supporting structure and stabilize the pump gap. Further, the supporting mesh 50 is at least two polygonal holes with unequal side lengths, and the polygonal holes may be irregular polygonal holes or polygonal holes with mirror symmetry structures, which is not limited in the present application.

Wherein the strain of the main body portion 40 of the stent 6 comprises the strain of the longest edges (501, 502) of the supporting mesh 50. The longest edge should be the degree of variation in edge length between the two end points of the longest edge. The strain of the transition 48 includes the degree of change in the length of the transition rib 481.

As shown in fig. 7 and 8, in the naturally expanded state, the edge length of the longest edge is L1, the circumferential width is Lk1, and the mesh axial length is Lc1. In the radially folded state, the edge length of the longest edge is L2, the circumferential width is Lk2, and the axial length of the mesh is Lc2. Wherein the axial length variation of the support mesh 50 is mainly due to the variation of the circumferential width Lk of the mesh. The edge length L2 of the longest edge is slightly greater than L1, and is approximately equal. As shown in fig. 9, the length of the transition portion 48 (transition rib 481') in the radially collapsed state is significantly greater than the length of the transition rib 481 in the naturally expanded state. The strain of a single longest edge is low and even if the strains of multiple longest edges in the axial direction are superimposed, the overall strain of the main body portion 40 is lower than that of the transition portion 48.

In this embodiment, the support mesh 50 is a mirror-symmetrical mesh, and the length direction of the smallest edge of the support mesh 50 is parallel to the axial direction. The support mesh 50 includes two parallel first edges 501 and two parallel second edges 502. The second vertex 504 is located at least one end of the second edge 502, and the first vertex 505 is located at least one end of the first edge 501. The first edge 501 and the second edge 502 are equal in length and are arranged in mirror symmetry. First edge 501 and second edge 502 are the longest edges of support mesh 50, and are approximately the same strain, and are symmetrically designed.

The support meshes 50 may be quadrangular holes such as rhombic holes or hexagonal holes. For example, the support mesh 50 may be a diamond mesh having a predominant axial dimension, the diamond mesh 50 having two axial first vertices 505 forming leading and trailing

crests

510a and 510b of a sawtooth structure for the first and

second rims

501 and 502, respectively. Two second apexes 504 are opposite to each other in the circumferential direction, and the first edge 501 and the second edge 502 form a left crest and a right crest of the saw-tooth structure, respectively.

As shown in fig. 4 and 5, the support mesh 50 is a hexagonal hole having mirror symmetry. In particular, the supporting mesh 50 further comprises two third edges 503 parallel to the axial direction. A third edge 503 is connected between a first edge 501 and a second edge 502, and the first edge 501, the second edge 502, and the third edge 503 enclose to form the closed hexagonal supporting mesh 50. The axial length of the support mesh 50 in this embodiment is substantially equal to its radial projection on the axis.

The axial size of the supporting mesh 50 is increased through the third edge 503, so that the axial size of the supporting mesh 50 is the main size, and further, when the supporting mesh is put into the sheath, the supporting mesh can be folded smoothly along the axial direction, and the resistance force during folding is reduced. Further, the length of the second edge 502 is equal to the length of the first edge 501, and the length of the third edge 503 is smaller than the length of the second edge 502. The third edge 503 is the smallest edge that supports the mesh 50, providing the smallest edge length of the mesh.

The two axial end points of the third edge 503 respectively form second vertexes 504, the rear axial end point of the third edge 503 is shared with a first edge 501, the shared end point forms a second vertex 504, the front axial end point of the third edge 503 is shared with a second edge 502, and the shared end point forms another second vertex 504. The circumferential distance between the two third edges 503 is the distance between the two circumferentially opposite second apexes 504. The common end point of the first edge 501 and the second edge 502 forms a first vertex 505. The first vertex 505 is provided with a first rounded configuration and the second vertex 504 is provided with a second rounded configuration. By providing a rounded structure to provide a smooth transition between the edges of the support mesh 50, a stable support structure is constructed.

At least one of the first edge 501, the second edge 502 and the third edge 503 is a linear edge as a whole, a plurality of edges of the mesh form a polygonal mesh, and the edge is a linear edge as a whole, which can be a linear edge without bending as shown in fig. 4 and 5. Alternatively, the edges may be straight edges that allow some slight curvature and still be visually perceived as polygons.

In the embodiment of the present disclosure, the edges of the polygonal mesh may be formed in a linear configuration as a whole.

As shown in fig. 5, the plurality of support meshes 50 are arranged in order in the circumferential direction to form support rings (50 a, 50b, 50 c), and the plurality of support rings are arranged in the axial direction to form the main body 40. As shown in fig. 5, along the circumferential direction, the first edge 501 and the second edge 502 are alternately arranged to form a sawtooth ring 520 in a sawtooth structure, and two axially adjacent sawtooth rings 520 are opposite to each other to form a support annular ring.

The main body section 50 has three

support grommets

50a, 50b, 50c arranged in the axial direction. The serration rings 520 have front tooth tops 510a facing the inlet portion 41 and rear tooth tops 510b facing the outlet portion 42, and a plurality of serration rings 520 are arranged in a circumferential direction, and the front tooth top 510a of one serration ring 520 is axially opposite to the rear tooth top 510b of the other serration ring 520 in two adjacent serration rings 520.

In the present embodiment, the front tooth top 510a of one serration ring 520 is axially connected to the rear tooth top 510b of the other serration ring 520 by a third edge 503 parallel to the axial direction (for example, integrally formed or welded) to form a hexagonal supporting mesh 50. Accordingly, each support ring includes a plurality of hexagonal support mesh openings 50 arranged in a circumferential direction.

In other embodiments, the front tips 510a of one serration ring 520 are directly connected to the rear tips 510b of the other serration ring 520 in the axial direction to form a diamond-shaped support mesh 50. Accordingly, each support ring includes a plurality of diamond-shaped support mesh openings 50 arranged circumferentially.

The cone-shaped part comprises two overflowing mesh holes which are alternately distributed along the circumferential direction and have different shapes. The meshes 52 of the inlet portion 41 comprise first overflowing meshes and second overflowing meshes which are alternately distributed along the circumferential direction, and the meshes 51 of the outlet portion 42 comprise third overflowing meshes and fourth overflowing meshes which are alternately distributed along the circumferential direction. The first overflowing meshes are closed holes, and the second filtering meshes are non-closed holes. The outlet portion 42 is substantially similar to the inlet portion 41, except that the third and fourth flow-through meshes are closed holes.

As shown in fig. 3 and 4, the inlet portion 41 is located at the front side of the main body portion 40 at the distal end of the foldable support 6, and the mesh of the inlet portion 41 extends between both axial ends by a length greater than the axial length of the support mesh 50.

The meshes 52 of the inlet portion 41 are flow-through meshes which can supply the inlet portion of the stent 6 with the medium flowing in. The mesh of the inlet portion 41 has an extension length from the front end to the rear end of the mesh or from the proximal end to the distal end of the mesh, not a radial projection length on the axis.

Specifically, one end of the inlet portion 41, which is far away from the main body portion 40, is further provided with a front connecting portion 44, the front connecting portion 44 includes a plurality of circumferentially distributed connecting legs 440, and the connecting legs 440 are in a T-shaped structure. The distal end of connecting landing leg 440 has the leg end 45 that the circumference size is greater than the landing leg body of rod, connects on landing leg 440 can block into the draw-in groove on the outer wall of distal end bearing room, and the distal end of draw-in groove communicates a ring channel, and the landing leg body of rod card of connecting landing leg 440 is blocked to the draw-in groove, and its leg end 45 card is blocked to the ring channel to fix a plurality of connection landing legs 440 that will disperse on the distal end bearing room through outer hoop.

In the present embodiment, the inlet portion 41 includes a plurality of front tension ribs 528 extending from the front crests 510a to the front connecting portions 44; the ends of two adjacent front tension ribs 528 that are away from the main body portion 40 meet to form a front meeting point. The plurality of front junctions are connected to or extend to the connecting legs 440 in a one-to-one correspondence. The number of front tension ribs 528 is equal to the number of front crests 510a of a serrated ring 520 and is 2 times the number of connecting legs 440.

Looking again at the exit 42, the exit 42 is located at the proximal end of the foldable support 6. The mesh 51 of the outlet portion 42 extends between the axial ends over a length greater than the axial length of the support mesh 50. The end of the outlet part 42, which is far away from the main body part 40, is further provided with a connection secondary tube 43, and the connection secondary tube 43 can be sleeved on the outer wall of the catheter and fixed on the catheter or the proximal bearing chamber in a hot melting or gluing manner, so that the proximal fixation of the foldable support 6 is realized. The secondary connection tube 43 may further have a locking hole for locking the outer wall of the guide tube or the proximal bearing chamber.

Specifically, the outlet portion 42 includes a plurality of rear extension ribs 518 extending from the rear tooth top 510b toward the connection sub-pipe 43. The ends of two adjacent rear tension ribs 518 distal from the main body portion 40 meet to form a rear meeting point. The plurality of rear junctions are connected to or extend to the connection legs 440 in a one-to-one correspondence. The number of rear tension ribs 518 is equal to the number of rear crests 510b of a serration ring 520, and is 2 times the number of connecting legs 440.

In this embodiment, the distal transition 48 is located on the front tension rib. The proximal transition 48 is located at the rear tension rib 518. A rear tension rib 518 extends from the rearmost rear tooth tip towards the proximal end of the stent 6. The front tension rib 528 extends from the forward most tooth top toward the distal end of the bracket 6. As shown in fig. 6 and 9, the partial stretch ribs 482 are located in the main body portion 40, the majority of the stretch ribs 480 are located in the tapered portion, and the transition ribs 481 are engaged between the two

partial stretch ribs

482, 480. The partially stretched ribs 518/528 form transition ribs 481. The partial forward tension rib forms the transition rib 481 of the distal transition 48 a; the partial trailing stretch rib forms the transition rib 481 of the proximal transition 48 b.

It is to be understood that the above description is intended to be illustrative, and not restrictive. Many embodiments and many applications other than the examples provided will be apparent to those of skill in the art upon reading the above description. The scope of the present teachings should, therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are hereby incorporated by reference for all purposes. The omission in the foregoing claims of any aspect of subject matter that is disclosed herein is not intended to forego such subject matter, nor should the inventors be construed as having contemplated such subject matter as being part of the disclosed subject matter.

Claims

1. A pump casing for a catheter pump, the pump casing comprising a support capable of receiving an impeller, a membrane defining a blood flow passage, the membrane covering a portion of the support; the pump housing has a radially collapsed state adapted for intervention or delivery within a subject's vasculature and a natural expanded state when the corresponding impeller is not rotating;

in a naturally expanded state, the bracket includes a substantially cylindrical main body portion, and substantially tapered portions provided at both ends of the main body portion in an axial direction; a transition part is arranged between the conical part and the main body part; wherein, when the stent is switched from the radially collapsed state to the naturally expanded state, the strain of the transition portion is greater than the strain of the main body portion, and the strain of the transition portion is greater than the strain of the cone portion.

2. A pump casing according to claim 1 wherein the tapered portion at the distal end of the body portion is an inlet portion and the tapered portion at the proximal end of the body portion is an outlet portion; a far-end transition part is arranged between the inlet part and the main body part, and a near-end transition part is arranged between the main body part and the outlet part; the transition portion comprises a plurality of transition ribs which are distributed discontinuously in the circumferential direction.

3. The pump casing according to claim 2, wherein the main body portion is distributed with a plurality of support mesh holes of polygonal shape; the strain of the body portion includes the strain of the longest edge of the support mesh; the degree of variation of the length of the edge between the two end points of the longest edge; the strain of the transition portion includes a degree of change in length of the transition rib.

4. The pump casing of claim 1 wherein said transition portion assumes an arcuate configuration in said naturally expanded state and a generally linear configuration or slightly curved configuration having a curvature less than said arcuate configuration in said radially collapsed state.

5. The pump casing of claim 1 wherein the transition portion has a curvature in the radially collapsed state that is less than a curvature in the naturally expanded state.

6. The pump casing of claim 1 wherein the axial length of the stent changes by a greater degree than the strain of the transition portion when the stent is switched from the radially collapsed state to the naturally expanded state.

7. The pump casing of claim 1 wherein the transition portion includes a smooth outer transition surface extending from the body portion to the tapered portion.

8. The pump casing of claim 1 wherein said transition is a rounded configuration; the curvature radius of the transition part is 0.8mm-1.5mm; the extension length of the transition part is 1mm-2mm, and further, the extension length of the transition part is 1.2mm-1.7mm.

9. A pump casing according to claim 2 wherein the body portion comprises a plurality of toothed rings arranged in an axial direction, the toothed rings having a leading crest directed towards the inlet portion and a trailing crest directed towards the outlet portion; the front tooth top of one sawtooth ring in the two adjacent sawtooth rings is arranged opposite to the rear tooth top of the other sawtooth ring along the axial direction;

10. A catheter pump, comprising:

a motor;

a conduit;