Catheter pump

Abstract

A catheter pump, comprising: a catheter and a pump head located at the distal end of the catheter and used for pumping blood. The pump head comprises a pump housing provided with a blood inlet and a blood outlet; the pump housing comprises a stent and a graft that are connected to the distal end of the catheter; the stent is operably switched between a radial folded state and a radial unfolded state; in the radial unfolded state, the stent comprises a body portion covered with the graft, an inlet portion located at the axial distal end of the body portion and an outlet portion located at the axial proximal end of the body portion; the inlet portion and the outlet portion are connected to and support the body portion; a distal end connecting portion is connected to the distal end of the inlet portion; and the graft comprises a first connecting portion and a second connecting portion located at the distal end thereof, the second connecting portion is connected to the distal end of the first connecting portion, at least part of the first connecting portion is located on the outer surface of the inlet portion, the second connecting portion is located on the outer surface of the distal end connecting portion and is fixedly connected to the distal end connecting portion, and the circumferential width of the second connecting portion is greater than that of the first connecting portion.

Description

Catheter pump

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on July 31, 2023, with application number 202322037299.5 and invention name “Catheter Pump”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present disclosure relates to the field of medical devices, and in particular to a catheter pump. Background Art

[0003] Catheter pumps are divided into non-foldable and foldable types. Among them, the foldable catheter pump has the advantage of being more convenient and quick to use due to the smaller incision during intervention.

[0004] The foldable catheter pump has a foldable pump head, which includes a pump casing defined by a membrane and a bracket, and an impeller located in the bracket. The bracket generally includes a pump portion located in the middle and roughly cylindrical, an inlet portion and an outlet portion located at both axial ends of the pump portion and roughly conical. The inlet portion located at the distal end of the bracket is located outside the distal end of the membrane body of the membrane along the axial direction, and the bracket supports and maintains the distal shape of the membrane to unfold the membrane. The membrane can be sleeved on the outside of the bracket and fixedly connected to the bracket by means such as bonding. The bracket applies a constraint to the distal end of the membrane so that it expands or folds with the bracket to prevent the two from separating.

[0005] However, the folding of the distal end of the stent can easily cause the adhesive coating to fall off. Increasing the coverage area of ​​the distal end of the stent can make the connection between the coating and the stent more stable and prevent the coating from falling off. However, too large a coverage area will reduce the blood inlet, thereby affecting the blood pumping function of the catheter pump.

[0006] Summary of the Invention

[0007] In view of the deficiencies in the prior art, an object of the present disclosure is to provide a catheter pump that can prevent the covering from falling off and does not affect the blood inlet.

[0008] A catheter pump comprises: a catheter and a pump head located at the distal end of the catheter for pumping blood; the pump head comprises a pump housing having a blood inlet and a blood outlet; the pump housing comprises a stent and a coating connected to the distal end of the catheter; the stent is operable to switch between a radially collapsed state and a radially expanded state; in the radially expanded state, the stent comprises a main body covered by the coating, an inlet located at the axial distal end of the main body, and an outlet located at the axial proximal end of the main body, the inlet and outlet being connected to and supporting the main body; the distal end of the inlet is connected to a distal connecting part; wherein the coating comprises a first connecting part and a second connecting part located at the distal end, the second connecting part being connected to the distal end of the first connecting part, at least a portion of the first connecting part being located on the outer surface of the inlet part, the second connecting part being located on the outer surface of the distal connecting part and being fixedly connected to the distal connecting part, and the circumferential width of the second connecting part being greater than the circumferential width of the first connecting part.

[0009] In one example, the inlet portion includes a plurality of connecting ribs connected between the main body portion and the distal connecting portion, and the circumferential width of the first connecting portion is less than or equal to the maximum circumferential width of the connecting ribs.

[0010] In one example, when the second connection portion is connected to the distal connection portion, the second connection portion has no overlapping portion.

[0011] In one example, the number of the first connection parts and the number of the second connection parts are equal, and the number of the first connection parts is multiple.

[0012] In one example, the coating includes a cylindrical segment whose distal end is connected to the first connecting portion, and the cylindrical segment covers the outer surface of the main body; and the plurality of first connecting portions are evenly distributed along the circumference of the cylindrical segment.

[0013] In one example, the axial lengths and / or circumferential widths of the plurality of second connecting portions are equal.

[0014] In one example, the multiple first connection parts have equal axial lengths and are all located on the outer surface of the inlet part, and the multiple second connection parts are fixedly connected to the outer surface of the distal connection part in sequence along the circumferential direction.

[0015] In one example, the sum of the circumferential widths of the plurality of second connecting portions is substantially equal to the circumferential width of the distal connecting portion.

[0016] In one example, the axial length of the second connecting portion is equal to the axial length of the distal connecting portion.

[0017] In one example, the axial lengths of the plurality of first connection parts are not equal, some of the first connection parts are located on the outer surface of the distal connection part, and the plurality of second connection parts are fixedly connected to the outer surface of the distal connection part in sequence along the axial direction.

[0018] In one example, the sum of the axial lengths of the plurality of second connecting portions is substantially equal to the axial length of the distal connecting portion.

[0019] In one example, the circumferential width of the second connecting portion is greater than half of the circumferential width of the distal connecting portion and smaller than the circumferential width of the distal connecting portion.

[0020] In one example, the distal connecting part includes a connecting leg, the distal connecting part is connected to the distal bearing chamber, and the outer wall of the distal bearing chamber is provided with a groove for accommodating the connecting leg; the second connecting part is fixedly sleeved on the outer wall of the distal bearing chamber.

[0021] In one example, the second connecting portion is provided with a distal collar for radially fixing the connecting legs, and the distal collar can fix the second connecting portion to the outer surface of the distal connecting portion.

[0022] In one example, the total width of the first connecting portion in the circumferential direction is 1 / 5 to 1 / 20 of the maximum circumference of the entrance portion.

[0023] In one example, the total circumferential width of the first connecting portion is 1 / 5 to 1 / 10 of the maximum circumference of the entrance portion.

[0024] The catheter pump provided in this embodiment provides a first connecting portion and a second connecting portion connected to each other at the distal end of the coating, so that at least a portion of the first connecting portion is located on the outer surface of the inlet portion of the stent, and the second connecting portion is located on the outer surface of the distal connecting portion of the stent and fixedly connected to the distal connecting portion. The second connecting portion can increase the connection strength between the coating and the stent, effectively preventing the coating from falling off when the distal end of the stent is folded; at the same time, the first connecting portion minimizes the area of ​​the coating blocking the inlet portion, thereby not affecting the blood inlet. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG1 is a schematic structural diagram of a coating provided by an embodiment of the present disclosure before installation;

[0026] FIG2 is a schematic structural diagram of the film in FIG1 after installation;

[0027] FIG3 is a schematic structural diagram of a coating before installation provided by another embodiment of the present disclosure;

[0028] FIG4 is a schematic structural diagram of the film in FIG3 after installation;

[0029] FIG5 is a schematic structural diagram of a film installed on a bracket according to an embodiment of the present disclosure;

[0030] FIG6 is a schematic structural diagram of FIG5 from another perspective;

[0031] FIG7 is a schematic structural diagram of a stent in a radially expanded state provided by one embodiment of the present disclosure;

[0032] FIG8 is a schematic structural diagram of a catheter pump provided by another embodiment of the present disclosure;

[0033] FIG. 9 is a partial cross-sectional view of FIG. 8 .

[0034] Description of reference numerals: 1000, catheter pump; 100, power assembly; 101, housing; 200, working assembly; 201, Catheter; 202, drive shaft; 2021, flexible shaft; 2022, hard shaft; 204, drive catheter handle; 205, pump head; 2051, pump housing; 2051a, blood inlet; 2051b, blood outlet; 20511, bracket; 20512, membrane; 2052, impeller; 20521, hub; 206, proximal bearing chamber; 207, distal bearing chamber; 208, proximal bearing; 209, distal bearing; 210, non-invasive support member; 73, distal collar; 11, main body; 12, inlet; 121, connecting rib; 13, outlet; 14, proximal connecting portion; 15, distal connecting portion; 16, first connecting portion; 17, second connecting portion; 18, cylindrical section; X, axial DETAILED DESCRIPTION

[0035] The terms "proximal," "posterior," "distal," and "front" used in this disclosure are relative to the physician operating the catheter pump. The terms "proximal" and "posterior" refer to the portion relatively close to the physician, while the terms "distal" and "front" refer to the portion relatively far from the physician. For example, the portion outside the body is at the proximal or posterior end, and the portion inserted into the body is at the distal or anterior end. The catheter pump of this disclosure defines "axial direction" or "axial extension direction" based on the extension direction of the drive shaft. The terms "inner" and "outer" are relative to the centerline of the axial extension, with the direction relatively close to the centerline being "inner" and the direction relatively far from the centerline being "outer."

[0036] It should be understood that the terms "near," "far," "back," "front," "inside," and "outside" are defined for ease of description. However, catheter pumps can be used in many orientations and positions, so these terms expressing relative positional relationships are not restrictive or absolute. For example, the above definitions of various directions are merely for the convenience of illustrating the technical solutions of the present disclosure and do not limit the orientation of the catheter pump of the present disclosure in scenarios that may cause it to be inverted or repositioned, including but not limited to product testing, transportation, and manufacturing. In this disclosure, if the above definitions are otherwise clearly defined and limited, they shall follow such clear definitions and limitations.

[0037] Referring to Figures 8 and 9, the catheter pump 1000 of one embodiment of the present disclosure can be at least partially inserted into the subject to assist the heart's pumping function and reduce the heart's burden. In a scenario suitable for left ventricular assist, the catheter pump 1000 pumps blood from the left ventricle into the aorta to provide support for blood circulation, reduce the subject's heart workload, or provide additional continuous pumping power support when the heart's pumping capacity is insufficient. Of course, the catheter pump 1000 can also be inserted into other target locations of the subject as desired through interventional surgery, such as the right ventricle, blood vessels, or other organs.

[0038] As shown in Figure 8, the catheter pump 1000 includes a power assembly 100 and a working assembly 200. The power assembly 100 includes a housing 101, a motor (not shown) housed in the housing 101, and an active member (not shown) driven by the motor. In conjunction with Figure 9, the working assembly 200 includes a catheter 201, a drive shaft 202 inserted into the catheter 201, a driven member connected to the proximal end of the drive shaft 202, and a drive catheter handle 204 and a pump head 205 connected to the proximal and distal ends of the catheter 201, respectively. The pump head 205 can be delivered to a desired location in the heart, such as the left ventricle, through the catheter 201 to pump blood. The pump head 205 includes a pump housing 2051 having a blood inlet 2051a and a blood outlet 2051b, and an impeller 2052 housed in the pump housing 2051. The blood inlet 2051a is located at the distal end of the pump housing 2051, and the blood outlet 2051b is located at the proximal end of the pump housing 2051. The motor is located at the proximal end of the catheter 201 and drives the impeller 2052 to rotate and pump blood via the drive shaft 202. The impeller 2052 is connected to the distal end of the drive shaft 202. When the impeller 2052 rotates, blood is drawn into the pump housing 2051 through the blood inlet 2051a and then pumped out of the pump housing 2051 through the blood outlet 2051b.

[0039] The pump housing 2051 is connected to the distal end of the catheter 201, and the impeller 2052 is connected to the distal end of the drive shaft 202. The pump housing 2051 includes a membrane 20512 that defines a blood flow channel and a foldable support 20511 that supports the expansion of the membrane 20512. The proximal end of the support 20511 is connected to the distal end of the catheter 201. In other embodiments, the support may also be another type of expansion mechanism, configured to expand into a fixed shape and cooperate with the membrane to form a corresponding blood inlet.

[0040] The coating 20512 is elastic and covers a portion of the bracket 20511 , while the other portion is uncovered and serves as an inlet and outlet for blood. The impeller 2052 is housed in the bracket 20511 and is located in the coating 20512 .

[0041] A distal bearing chamber 207 is provided at the distal end of bracket 20511. Within distal bearing chamber 207 is a distal bearing 209 that rotationally supports the distal end of drive shaft 202. Drive shaft 202 comprises a flexible shaft 2021 that passes through conduit 201, and a rigid shaft 2022 that extends through the hollow passage of hub 20521 and connects to the distal end of flexible shaft 2021. Hub 20521 of impeller 2052 is sleeved onto rigid shaft 2022, with the proximal and distal ends of rigid shaft 2022 respectively passing through proximal bearing 208 and distal bearing 209. Thus, rigid shaft 2022 is supported at both ends by two bearings. Combined with its high rigidity, rigid shaft 2022 provides rigid support for impeller 2052 within pump housing 2051, effectively retaining impeller 2052 within pump housing 2051 and maintaining its stable position within pump housing 2051.

[0042] The distal end of the distal bearing chamber 207 is provided with a non-invasive support member 210 made of flexible material. The non-invasive support member 210 is supported on the inner wall of the ventricle in a non-invasive or non-destructive manner, separating the blood inlet 2051a of the pump head 205 from the inner wall of the ventricle, preventing the blood inlet 2051a of the pump head 205 from sticking to the inner wall of the ventricle due to the reaction force of the blood during the operation of the pump head 205, thereby ensuring the effective pumping area.

[0043] The drive catheter handle 204 and the power assembly 100 are detachably connected, and the connection method can adopt a locking nut or a snap connection provided by US9421311B2. The driven member and the active member are non-contact coupled to transmit the rotational power of the motor to the drive shaft 202, thereby driving the impeller 2052 to rotate and pump blood. As mentioned above, the driven member and the active member can adopt a magnetic coupling method such as provided by CN103120810B or CN101820933B, or a coupling method such as an eddy current coupling (Eddy Current Coupling) provided by CN216061675U or CN114452527A, which is not limited in this embodiment.

[0044] Referring to FIG. 7 , the stent 20511 of the embodiment of the present disclosure is operable to switch between a radially collapsed state and a radially expanded state. In the radially expanded state, the stent 20511 includes a generally cylindrical main body 11 covered by a coating 20512, and a generally conical inlet 12 and outlet 13 located at the distal and proximal ends of the main body 11 in the axial direction X, respectively. The inlet 12 and the outlet 13 connect and support the main body 11. A blood inlet 2051a is formed at the location of the inlet 12. The proximal end of the outlet 13 is connected to a proximal connecting portion 14, and the distal end of the inlet 12 is connected to a distal connecting portion 15.

[0045] The proximal connection portion 14 and the distal connection portion 15 are used to connect the stent 20511 to other components at the proximal and distal ends, respectively. For example, the proximal connection portion 14 can connect the stent 20511 to the proximal bearing chamber 206 or the catheter 201, and the distal connection portion 15 can connect the stent 20511 to the distal bearing chamber 207 or the non-invasive support member 210.

[0046] Referring to Figures 1 to 4 , in this embodiment, the covering 20512 includes a first connecting portion 16 and a second connecting portion 17 located at the distal end. The second connecting portion 17 is connected to the distal end of the first connecting portion 16, with at least a portion of the first connecting portion 16 located on the outer surface of the inlet portion 12. The second connecting portion 17 is located on the outer surface of the distal connecting portion 15 and is fixedly connected to the distal connecting portion 15. Thus, the second connecting portion 17 increases the connection strength between the covering 20512 and the stent 20511, effectively preventing the covering 20512 from falling off when the distal end of the stent 20511 is folded. Simultaneously, the first connecting portion 16 minimizes the area blocked by the covering 20512 from the inlet portion 12, thereby preventing it from affecting the blood inlet 2051a. Specifically, the second connecting portion has an opening. During installation, the first connecting portion 16 is first attached to the stent. Then, the distal second connecting portion 17 surrounds and covers the outer surface of the distal connecting portion 15 and is fixedly connected to the distal connecting portion 15, thereby achieving a convenient fixed connection.

[0047] Specifically, the coating 20512 further includes a cylindrical segment 18 whose distal end is connected to the first connecting portion 16. This cylindrical segment 18 covers the outer surface of the main body 11. The first connecting portion 16 is connected to the distal end of the cylindrical segment 18. When the stent 20511 is in the radially expanded state, the first connecting portion 16, located on the outer surface of the inlet portion 12, is generally conical. The proximal end of the cylindrical segment 18 is disposed outside the catheter 201 and fixed to the outer wall of the catheter 201.

[0048] In this embodiment, the stent 20511 is supported at the distal end of the coating 20512, with a portion of the stent 20511 located outside the distal end of the coating 20512 and another portion of the stent 20511 located within the coating 20512. The coating 20512 covers the middle and rear ends of the stent 20511. The mesh in the front end of the stent 20511 not covered by the coating 20512 forms the blood inlet 2051a. The rear end of the coating 20512 covers the exterior of the distal end of the catheter 201, and the blood outlet 2051b is an opening formed at the rear end of the coating 20512.

[0049] As shown in Figures 1 and 3 , the circumferential width of the second connecting portion 17 is greater than the circumferential width of the first connecting portion 16. This is because at least a portion of the first connecting portion 16 is located on the outer surface of the inlet portion 12. Reducing the circumferential width of the first connecting portion 16 can reduce the area of ​​the blood inlet 2051a blocked by the membrane 20512, while increasing the circumferential width of the second connecting portion 17 can further increase the connection strength between the membrane 20512 and the stent 20511. Specifically, as shown in Figures 5 and 6 , the inlet portion 12 includes a plurality of connecting ribs 121 connected between the main body 11 and the distal connecting portion 15. The circumferential width of the first connecting portion 16 is less than or equal to the maximum circumferential width of the connecting ribs 121 to minimize obstruction of the blood inlet 2051a by the first connecting portion 16.

[0050] In this embodiment, when the second connecting portion 17 is connected to the distal connecting portion 15, there is no overlap between the second connecting portion 17 and the distal connecting portion 15. That is, the outer surface of the distal connecting portion 15 has at most one layer of the second connecting portion 17. This prevents the second connecting portion 17 from being too thick, thereby helping to reduce the size of the catheter pump 1000 and facilitating miniaturization of the catheter pump 1000. In other embodiments, the second connecting portion may also wrap around the distal connecting portion 15 in an integral number of circles to minimize unnecessary overlap.

[0051] In other embodiments, the outer surface of the distal connection portion 15 is fixedly provided with only two layers of the second connection portion 17 , without increasing the thickness by more than two layers, and can increase the connection strength between the coating 20512 and the bracket 20511 .

[0052] In this embodiment, the number of first connecting portions 16 and second connecting portions 17 is equal, and the distal end of each first connecting portion 16 is connected to a second connecting portion 17. To ensure uniform force across the coating 20512, multiple first connecting portions 16 are provided, such as two, three, or four. In one embodiment, the multiple first connecting portions 16 are evenly distributed along the circumference of the cylindrical segment 18, thereby ensuring that the cylindrical segment 18 is evenly connected to the multiple second connecting portions 17, uniformly increasing the connection strength between the coating 20512 and the stent 20511.

[0053] In one embodiment, the axial X lengths and / or circumferential widths of the plurality of second connecting portions 17 are equal. When the axial X lengths and circumferential widths of the plurality of second connecting portions 17 are equal, the connection strength between the coating 20512 and the stent 20511 increased by each second connecting portion 17 can be equal.

[0054] Specifically, in this embodiment, the first connecting portion 16 is a strip-shaped structure with a constant width, which can maintain a stable connection strength. The total circumferential width of the first connecting portion 16 is 1 / 10 of the maximum circumference of the inlet portion 12. In other embodiments, the width can also be in the range of 1 / 5 to 1 / 20.

[0055] In other embodiments, the width of the first connecting portion 16 may also change synchronously with the change trend of the entrance portion 12 from the proximal end to the distal end, that is, from wide to narrow, but the proportion of the total width of the first connecting portion 16 in the circumferential direction at the circumference of the corresponding entrance portion 12 position remains unchanged, that is, the proportion of the opening of the entrance portion remains unchanged.

[0056] In one embodiment, as shown in Figures 1 and 2, the axial X lengths of the plurality of first connecting portions 16 are equal and are all located on the outer surface of the inlet portion 12, and the plurality of second connecting portions 17 are fixedly connected to the outer surface of the distal connecting portion 15 in sequence along the circumferential direction. This structure is simple, and the first connecting portions 16 do not need to extend to the outer surface of the distal connecting portion 15. While ensuring that the coating 20512 is not easy to fall off and does not affect the blood inlet 2051a, the structure of the coating 20512 can be simplified.

[0057] In one embodiment, the sum of the circumferential widths of the plurality of second connecting portions 17 is approximately equal to the circumferential width of the distal connecting portion 15. The term "approximately equal" includes two situations. In one situation, the sum of the circumferential widths of the plurality of second connecting portions 17 can be equal to the circumferential width of the distal connecting portion 15, so that the plurality of second connecting portions 17 exactly surround the distal connecting portion 15, utilizing the entire circumferential width of the distal connecting portion 15 to increase the connection strength between the coating 20512 and the stent 20511. In another situation, the sum of the circumferential widths of the plurality of second connecting portions 17 can be slightly smaller than the circumferential width of the distal connecting portion 15, and a certain gap can be provided between the second connecting portions 17 in the circumferential direction. This configuration ensures that the second connecting portions 17 do not overlap in the circumferential direction, thereby preventing the size of the catheter pump 1000 from increasing due to excessive thickness of the second connecting portions 17.

[0058] In another embodiment, the axial X length of the second connecting portion 17 is equal to the axial X length of the distal connecting portion 15, so that the second connecting portion 17 can cover the distal connecting portion 15 in the axial X direction, and the entire circumferential length of the distal connecting portion 15 is used to increase the connection strength between the coating 20512 and the bracket 20511.

[0059] In another embodiment, as shown in Figures 3 and 4, the axial X lengths of multiple first connecting parts 16 are not equal, some of the first connecting parts 16 are located on the outer surface of the distal connecting part 15, and multiple second connecting parts 17 are fixedly connected to the outer surface of the distal connecting part 15 in sequence along the axial direction X. Each second connecting part 17 and the first connecting part 16 located on the outer surface of the distal connecting part 15 form a nested structure, which can further increase the connection strength between the coating 20512 and the bracket 20511.

[0060] In one embodiment, the sum of the axial lengths (X) of the plurality of second connecting portions 17 is approximately equal to the axial length (X) of the distal connecting portion 15. "Approximately equal" includes two situations. In one situation, the sum of the axial lengths (X) of the plurality of second connecting portions 17 can be equal to the axial length (X) of the distal connecting portion 15, so that the plurality of second connecting portions 17 completely cover the distal connecting portion 15 in the axial direction (X), utilizing the entire axial length (X) of the distal connecting portion 15 to increase the connection strength between the coating 20512 and the stent 20511. In another situation, the sum of the axial lengths (X) of the plurality of second connecting portions 17 can be slightly less than the axial length (X) of the distal connecting portion 15, and a certain gap can be provided between the second connecting portions 17 in the axial direction (X). This configuration ensures that the second connecting portions 17 do not overlap in the axial direction (X), thereby preventing the size of the catheter pump 1000 from increasing due to excessive thickness of the second connecting portions 17.

[0061] In one embodiment, the circumferential width of the second connecting portion 17 is greater than half the circumferential width of the distal connecting portion 15 and less than the circumferential width of the distal connecting portion 15. When there are two first connecting portions 16, the sum of the circumferential widths of one first connecting portion 16 and one second connecting portion 17 is approximately equal to the circumferential width of the distal connecting portion 15, thereby fully utilizing the entire circumferential width of the distal connecting portion 15 to increase the connection strength between the coating 20512 and the stent 20511.

[0062] In this embodiment, the distal connection portion 15 may include connecting legs (not shown). The distal connection portion 15 is connected to the distal bearing chamber 207. The outer wall of the distal bearing chamber 207 is provided with a groove (not shown) for accommodating the connecting legs, thereby ensuring a reliable and stable connection between the bracket 20511 and the distal bearing chamber 207. The second connection portion 17 is fixedly mounted on the outer wall of the distal bearing chamber 207 and is fixedly connected to the distal bearing chamber 207 along with the distal connection portion 15.

[0063] Specifically, a distal collar 73 is provided on the outer surface of the second connecting portion 17 for radially securing the connecting legs, thereby maintaining the connecting legs within the groove. The distal collar 73 also secures the second connecting portion 17 to the outer surface of the distal connecting portion 15, thereby achieving a fixed connection between the second connecting portion 17 and ensuring that the second connecting portion 17 can increase the connection strength between the coating 20512 and the stent 20511.

[0064] The above embodiments merely illustrate several implementations of the present disclosure, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the disclosed patent. It should be noted that a person of ordinary skill in the art would be able to make numerous variations and improvements without departing from the scope of the present disclosure, all of which fall within the scope of protection of the present disclosure. Therefore, the scope of protection of the disclosed patent shall be determined by the appended claims.

Claims

1. A catheter pump, comprising: A catheter and a pump head located at the distal end of the catheter for pumping blood; the pump head comprises a pump housing having a blood inlet and a blood outlet; the pump housing comprises a bracket and a covering connected to the distal end of the catheter; The stent is operable to switch between a radially collapsed state and a radially expanded state; in the radially expanded state, the stent comprises a main body covered by the coating, an inlet located at the axial distal end of the main body, and an outlet located at the axial proximal end of the main body, wherein the inlet and outlet are connected to and support the main body; the distal end of the inlet is connected to a distal connecting portion; Wherein, the coating includes a first connecting portion and a second connecting portion located at the distal end, the second connecting portion is connected to the distal end of the first connecting portion, at least part of the first connecting portion is located on the outer surface of the entrance portion, the second connecting portion is located on the outer surface of the distal connecting portion and is fixedly connected to the distal connecting portion, and the circumferential width of the second connecting portion is greater than the circumferential width of the first connecting portion. 2 . The catheter pump according to claim 1 , wherein the inlet portion comprises a plurality of connecting ribs connected between the main body portion and the distal connecting portion, and a circumferential width of the first connecting portion is less than or equal to a maximum circumferential width of the connecting ribs. 3 . The catheter pump according to claim 1 , wherein when the second connection portion is connected to the distal connection portion, the second connection portion has no overlapping portion. 4 . The catheter pump according to claim 1 , wherein the number of the first connection parts is equal to the number of the second connection parts, and the number of the first connection parts is plural.

5. The catheter pump according to claim 4, wherein the coating comprises a cylindrical section whose distal end is connected to the first connecting portion, the cylindrical section covers the outer surface of the main body; and a plurality of the first connecting portions are evenly distributed along the circumference of the cylindrical section; Preferably, the axial lengths and / or circumferential widths of the plurality of second connecting portions are equal. 6 . The catheter pump according to claim 4 , wherein the plurality of first connection portions have equal axial lengths and are all located on the outer surface of the inlet portion, and the plurality of second connection portions are fixedly connected to the outer surface of the distal connection portion in sequence along the circumferential direction.

7. The catheter pump according to claim 6, wherein the sum of the circumferential widths of the plurality of second connecting portions is substantially equal to the circumferential width of the distal connecting portion; Preferably, the axial length of the second connecting portion is equal to the axial length of the distal connecting portion.

8. The catheter pump according to claim 4, wherein the axial lengths of the plurality of first connection parts are not equal, a portion of the first connection parts are located on the outer surface of the distal connection part, and the plurality of second connection parts are fixedly connected to the outer surface of the distal connection part in sequence along the axial direction.

9. The catheter pump according to claim 8, wherein the sum of the axial lengths of the plurality of second connecting portions is substantially equal to the axial length of the distal connecting portion; Preferably, the circumferential width of the second connecting portion is greater than half of the circumferential width of the distal connecting portion and is less than or equal to the circumferential width of the distal connecting portion.

10. The catheter pump according to claim 1, wherein the distal connecting portion includes a connecting leg, the distal connecting portion is connected to a distal bearing chamber, and the outer wall surface of the distal bearing chamber is provided with a groove for accommodating the connecting leg; the second connecting portion is fixedly sleeved on the outer wall surface of the distal bearing chamber; the second connecting portion is outerly provided with a distal ring for radially fixing the connecting leg, and the distal ring can fix the second connecting portion to the outer surface of the distal connecting portion.

11. The catheter pump according to claim 1, wherein the total width of the first connecting portion in the circumferential direction is 1 / 5 to 1 / 20 of the maximum circumference of the inlet portion; Preferably, the total width of the first connecting portion in the circumferential direction is 1 / 5 to 1 / 10 of the maximum circumference of the inlet portion.

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