CN219207537U - Propelling structure and catheter with same - Google Patents

Abstract

The utility model relates to the technical field of medical equipment, and provides a propelling structure and a catheter with the same, wherein the propelling structure comprises a hypotube which is provided with a cavity; the pushing piece is formed by being separated from the hypotube, the cross-sectional area of the proximal end of the pushing piece is larger than that of the distal end of the pushing piece, the proximal end of the pushing piece is suitable for extending into the cavity and is fixedly connected with the inner wall surface of the distal cavity of the hypotube, and the distal end of the pushing piece is suitable for extending distally along the axial direction of the cavity. Through setting up the propulsion piece in the distal end of hypotube, through setting up the components of a whole that can function independently between this propulsion piece and the hypotube, the cross-sectional area of the proximal end of propulsion piece is greater than the cross-sectional area of its distal end, makes propulsion structure have good compliance and propulsive nature, then with the proximal end of propulsion piece and the distal end cavity internal wall fixed connection of hypotube to this can provide stable conveying power to the sacculus, and when meetting complicated and crooked blood vessel, the trafficability characteristic is better.

Description

Propelling structure and catheter with same

Technical Field

The utility model relates to the technical field of medical treatment, in particular to a propelling structure and a catheter with the same.

Background

Balloon catheters are used to dilate pathologically stenosed (or occluded) blood vessels. A balloon attached to a vascular catheter is inserted through an artery, such as the femoral artery (or radial artery, etc.), and is applied to a stenosed (or occluded) site of a blood vessel under X-ray control. The balloon is then slowly expanded after being pressurized, and the balloon can be pre-expanded without medicine carrying if serious stenosis is encountered, so as to facilitate the expanding treatment of the medicine carrying balloon, and the high pressure balloon, the scoring balloon, the double guide wire balloon, the cutting balloon and the like can be used according to the size of the stenosis, the blood vessel and the prior diseases.

In the prior art, a balloon catheter is disclosed, which comprises a hypotube, and in order to apply a good pushing force to a distal balloon by using the hypotube in actual use, the overall strength of the hypotube is improved, but when passing through a relatively complex and curved blood vessel, the hypotube is difficult to bend due to poor flexibility, so that the hypotube is difficult to pass through the blood vessel, even damage is caused to the inner wall surface of the blood vessel, and the operation of a doctor is inconvenient.

Disclosure of Invention

Therefore, the technical problem to be solved by the present utility model is to overcome the defects that the balloon catheter disclosed in the prior art comprises a hypotube, and in actual use, in order to apply a good pushing force to a distal balloon by using the hypotube, the strength of the whole hypotube is improved, but when passing through a relatively complex and curved blood vessel, the hypotube is difficult to bend due to poor flexibility, so that the hypotube is difficult to pass through the blood vessel, even causes some damage to the inner wall surface of the blood vessel, and is inconvenient for a doctor to operate, so as to provide a pushing structure and a catheter with the pushing structure.

A propulsion structure comprising: a hypotube having a lumen with at least one end open; the section area of the proximal end of the pushing piece is larger than the section area of the distal end of the pushing piece, the proximal end of the pushing piece is suitable for extending into the cavity and is fixedly connected with the inner wall surface of the distal cavity of the hypotube, and the distal end of the pushing piece is suitable for extending distally along the axial direction of the cavity.

Optionally, in the propulsion structure, laser welding is adopted between the propulsion piece and the hypotube.

Optionally, in the propulsion structure, at least one welding spot is formed between the propulsion member and the hypotube, and all welding spots are alternately arranged between the propulsion member and the hypotube at intervals.

Optionally, in the propulsion structure, a distance between two adjacent welding points is set to be 0.01mm-5mm, and a distance between the most distal welding point and the most distal end of the hypotube is set to be 0.5mm-2mm.

Optionally, in the propulsion structure, an oblique incision is formed at the distal end opening of the hypotube, and an inclination angle of the oblique incision is set to be 40 ° -75 °.

Optionally, in the pushing structure, the oblique incision is circular or elliptical.

Optionally, in the above propulsion structure, the distal end of the hypotube further includes an extension section adapted to extend out of the cavity, the extension section is in smooth transition connection with the oblique incision, and the proximal end of the propulsion member abuts against an inner wall surface of the extension section.

Optionally, in the propulsion structure, a transverse cross section of the extension section is in a U-shaped structure.

Optionally, in the above propulsion structure, the propulsion member includes at least a first uniform diameter section, a variable diameter section, and a second uniform diameter section that are connected in a smooth transition manner along a proximal end to a distal end of the propulsion member, where the first uniform diameter section is fixedly connected with the hypotube, and a radial area of the proximal end of the variable diameter section gradually decreases toward a distal end radial area of the second uniform diameter section.

Optionally, in the propulsion structure, a length ratio of the extension section to the first uniform diameter section is between 1:2 and 1:3.

Optionally, in the propulsion structure, the diameter of the second uniform-diameter section is 0.0508mm-0.1016mm; and/or the ratio of the length of the second uniform diameter section to the length of the variable diameter section is 1: 1.5-1:5.

Optionally, in the propulsion structure, the length of the propulsion member is 100mm-250mm.

Optionally, in the above propulsion structure, the propulsion member is made of stainless steel or nickel-titanium alloy.

Optionally, in the propulsion structure, a plurality of slits are formed around the circumference of the hypotube at least at a distal end portion thereof.

Optionally, in the above pushing structure, a distance between a most proximal end of the pushing member and a projection of a most proximal end of the oblique incision in an axial direction of the cavity is larger than a distance between two adjacent slits.

Optionally, in the pushing structure, a distance between the slit at the most proximal end and the slit at the most distal end of the pushing member is-5 mm-2mm; and/or the slit has a cut gap of 0.01mm-1.0mm.

A catheter, comprising: a propulsion structure, the propulsion structure being as described above.

Optionally, the catheter further includes: an outer tube having a proximal end adapted to be connected to a distal end of the hypotube and a distal end adapted to be connected to a proximal end of a balloon; an inner tube having a proximal end adapted to extend into the lumen of the outer tube, a distal end of the inner tube adapted to extend out of the balloon in an axial direction of the balloon.

The technical scheme of the utility model has the following advantages:

1. the utility model provides a propulsion structure, comprising: a hypotube having a lumen with at least one end open; the section area of the proximal end of the pushing piece is larger than the section area of the distal end of the pushing piece, the proximal end of the pushing piece is suitable for extending into the cavity and is fixedly connected with the inner wall surface of the distal cavity of the hypotube, and the distal end of the pushing piece is suitable for extending distally along the axial direction of the cavity.

In the propulsion structure of the structure, the propulsion piece is arranged at the far end of the hypotube, the propulsion piece and the hypotube are arranged in a split mode, the cross-section area of the near end of the propulsion piece is larger than that of the far end of the propulsion piece, so that the propulsion structure has good flexibility and propulsion performance, then the near end of the propulsion piece is fixedly connected with the inner wall surface of the far end cavity of the hypotube, stable conveying force can be provided for the balloon, and when encountering complex and bent blood vessels, the passing performance is good, stable conveying motion of the propulsion structure in the blood vessels is ensured, the inner wall surface of the blood vessels cannot be damaged, the defect that in the prior art, a balloon catheter disclosed in the prior art comprises the hypotube is overcome, and in order to apply good pushing force to the far end balloon by the hypotube, the overall strength of the hypotube is improved, but when the complex and bent blood vessels pass through, due to the poor flexibility of the hypotube, the flexible hypotube is difficult to bend, and even the inner wall surface of the blood vessels is damaged, and the operation of doctors is inconvenient is overcome.

2. In the propulsion structure provided by the utility model, a slit is formed around the peripheral surface of the hypotube at least at the distal end part thereof. Through setting up the slit, reduced the hardness of hypotube distal end, the hypotube of being convenient for is at the in-process of advancing along the blood vessel, when meetting the great blood vessel of crookedness, can carry out corresponding bending, guarantees the compliance of hypotube, improves the transportation stability.

3. In the propulsion structure provided by the utility model, the distal end of the hypotube further comprises an extension section, the extension section is in smooth transition connection with the oblique incision, and the proximal end of the propulsion piece is at least in abutting connection with the inner wall surface of the extension section. In the propulsion structure of the structure, the extension section is arranged at the far end of the hypotube, and can apply a bearing force to the propulsion piece, so that the connection stability between the propulsion piece and the hypotube is further improved.

4. In the propulsion structure provided by the utility model, at least a first uniform diameter section, a variable diameter section and a second uniform diameter section which are connected in a smooth transition manner are arranged along the proximal end to the distal end of the propulsion piece, wherein the first uniform diameter section is fixedly connected with the hypotube, and the radial area of the proximal end of the variable diameter section gradually decreases towards the radial area of the distal end of the second uniform diameter section. In the propelling structure of the structure, the radial dimension of the propelling piece is integrally set to be a variable diameter, so that the flexibility of the propelling piece can be further improved, and the stability of conveying in a blood vessel can be improved.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present utility model, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic diagram of a connection structure between a base and a pushing structure according to an embodiment of the present utility model;

FIG. 2 is a schematic diagram of the connection structure of the propulsion member and the hypotube;

FIG. 3 is a schematic view of three weld points between the propulsion member and the hypotube;

FIG. 4 is a schematic view of the structure of four welds between the propulsion member and the hypotube;

FIG. 5 is a schematic structural view of a pusher;

FIG. 6 is a schematic cross-sectional view of the constant diameter section B-B of FIG. 5;

FIG. 7 is a schematic cross-sectional view of the variable diameter section C-C of FIG. 5;

FIG. 8 is a schematic cross-sectional view of the connection structure of the inner and outer tubes and the hypotube and the pusher;

reference numerals illustrate:

1. a hypotube; 101. a slit; 102. an extension section;

2. a propulsion member; 201. a first uniform diameter section; 202. a reducing section; 203. a second uniform diameter section;

3. welding spots; 301. a first welding spot; 302. a second welding spot; 303. a third welding spot; 304. a fourth welding spot;

4. an outer tube; 5. an inner tube; 6. a stress dispersing tube; 7. a base body.

Detailed Description

The following description of the embodiments of the present utility model will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the utility model are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the description of the present utility model, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

In the present utility model, the distal end and the proximal end are both the proximal end with respect to the operator's operation end (not shown), and the end far from the operator's operation end is the distal end.

Example 1

This embodiment describes a propulsion structure, see fig. 1-8, comprising a hypotube 1 and a propulsion member 2, wherein the hypotube 1 has a cavity with at least one end open, the propulsion member 2 is formed separately from the hypotube, the propulsion member has a proximal end with a cross-sectional area larger than a distal end, the propulsion member is adapted to extend into the cavity, and is fixedly connected to an inner wall of the distal cavity of the hypotube, and the propulsion member has a distal end adapted to extend distally in an axial direction of the cavity.

After the hypotube 1 receives the effect of external force, it can be through outer tube 4 and inner tube 5 with the focus department transport motion of sacculus to distal end department, in the in-process of transport motion, this propulsion piece 2 can apply propelling movement to sacculus, outer tube 4 and inner tube 5, guarantee the stability of carrying, and set up propulsion piece 2 reducing, can guarantee the compliance of propulsion piece, this propulsion structure has good propulsive nature and compliance, in meetting crooked or complicated blood vessel, can be stable and smooth the passing through, guarantee the transportation motion that propulsion structure is stable in the blood vessel, can not cause the damage to the internal face of blood vessel.

When the device is specifically arranged, the propulsion piece 2 and the hypotube 1 can be subjected to laser welding, after the welding is finished, four welding spots are formed between the propulsion piece 2 and the hypotube 1, all the welding spots are alternately arranged between the propulsion piece 2 and the hypotube 1 at intervals, under the condition that the process is satisfied, the number of the welding spots is correspondingly adjusted so as to ensure the connection strength between the propulsion piece 2 and the hypotube 1, the interval between two adjacent welding spots can be 0.01mm-5mm,

referring to fig. 3, in a specific application, welding may be performed between the bottom surface of the contact between the propelling member 2 and the hypotube 1, and the welding spots 3 are located on the bottom surface of the contact between the propelling member 2 and the hypotube and are disposed near the proximal end of the propelling member 2, and the number of welding spots may be set to three, the three welding spots are uniformly disposed, and the interval is set to 1mm.

Referring to fig. 4, of course, welding may be performed on the side of the contact between the pushing member 2 and the hypotube 1, the number of welding spots 3 being four, specifically defined as first welding spot 301 and second welding spot 302 and third welding spot 303 and fourth welding spot 304, wherein the distance L1 between the first welding spot 301 and the second welding spot 302 and the third welding spot 303 is 0.25mm, the distance L2 between the third welding spot 303 and the fourth welding spot 304 is 0.1mm, the distance L3 from the fourth welding spot 304 to the most distal end of the hypotube 1 may be set to 0.5mm-2mm, and in this embodiment, 0.5mm may be specifically set, and in this specific setting, the four welding spots may be arranged in an S-shaped arrangement.

When the number of welding spots is set to be greater than three, a plurality of welding spots are arranged in an S-shape between the propelling part 2 and the hypotube 1.

Of course, the number of welding points between the propelling member and the hypotube may be one, and stable connection may be performed between the propelling member 2 and the hypotube 1.

In this embodiment, in order to facilitate the connection between the hypotube 1 and the propulsion member 2, the distal end opening of the hypotube 1 may be provided as an oblique incision, and the oblique angle of the oblique incision may be set between 40 ° and 75 °, as shown in fig. 3 and 4, and the 45 ° oblique incision is used to facilitate the connection operation between the hypotube 1 and the propulsion member 2 by way of example of 45 °, and in particular applications, the incision of the oblique incision may be provided in a circular or oval shape.

In this embodiment, in order to improve the ease of connection operation between the hypotube 1 and the propelling member 2, referring to fig. 2 and 8, an extension 102 is further included at the distal end of the hypotube 1, the extension 102 is smoothly connected with the oblique incision, the proximal end of the propelling member 2 is abutted against the inner wall surface of the extension 102, by providing the extension 102, a bearing force can be applied to the propelling member, the connection stability between the propelling member and the hypotube is further improved, and a welding point can be provided between the propelling member 2 and the extension 102.

Referring to fig. 4, the transverse cross section of the extension 102 may be in a U-shaped structure, and the ratio of the length from the most distal end of the extension 102 to the connection transition between the extension and the oblique incision to the length of the whole hypotube is between 1:4 and 1:5.

In this embodiment, in order to further improve the propelling performance and flexibility of the propelling structure, referring to fig. 5-7, at least a first uniform diameter section 201, a variable diameter section 202 and a second uniform diameter section 203 are connected in a smooth transition manner along the proximal end to the distal end of the propelling piece 2, where the first uniform diameter section 201 is fixedly connected with the hypotube 1, the radial area of the proximal end of the variable diameter section 202 gradually decreases towards the radial area of the distal end of the second uniform diameter section 203, for example, the variable diameter section 202 may be configured as a cone structure, the first uniform diameter section 201 is disposed on an end face with a larger area of the cone structure, and the second uniform diameter section 203 is disposed on an end face with a smaller area of the cone structure.

Of course, the variable diameter section 202 may be configured to be a nonlinear variable diameter.

In terms of expansion, the lengths of the first uniform diameter section 201 and the extension section 102 may be set to be the same, or the length of the first uniform diameter section 201 may be set to be greater than the length of the extension section 102, so as to increase the contact area between the first uniform diameter section 201 and the hypotube 1, and the radial area of the propelling member 2 may be set to be of a non-uniform surface structure, so that the flexibility of the propelling member 2 may be further improved while the connection stability with the hypotube 1 is ensured, and the radial section of the propelling member 2 may be set to be circular, i.e., the whole of the propelling member 2 may be set to be a propelling member 2 formed by cylinders with different radial dimensions.

In specific applications, the length ratio of the extension section 102 to the first uniform diameter section 201 may be set between 1:2 and 1:3, the overall length of the pushing member 2 may be set between 100mm and 250mm, the diameter of the first uniform diameter section 201 may be set between 0.0508mm and 0.1016mm, the diameter of the second uniform diameter section 203 may be set between 0.0312mm and 0.0414mm, the overall length of the pushing member 2 may be between 100mm and 250mm, the distance between the nearest end of the proximal end of the pushing member 2 and the farthest end of the distal end of the hypotube 1 may be set at L4, L4 may be 12.5mm, and the length ratio of the second uniform diameter section 203 to the variable diameter section 202 may also be set at 1: 1.5-1:5.

In this embodiment, the pushing member 2 is made of stainless steel or nitinol, and in a specific use, the material between the hypotube 1 and the pushing member 2 may be the same material, or may be different materials, which is specifically set according to the use environment.

Of course, the propelling member 2 may be configured to have a linear variable diameter, and specifically configured according to actual use.

In order to facilitate the hypotube 1 to bend correspondingly when encountering a blood vessel with larger curvature in the process of advancing along the blood vessel, the circumferential surface of the hypotube 1 can be surrounded, at least the distal end part of the hypotube is provided with a slit 101, the strength of the distal end part of the hypotube 1 can be reduced, the hypotube 1 can bend correspondingly when encountering a blood vessel with larger curvature in the process of advancing along the blood vessel, and the conveying stability and flexibility are improved.

In specific applications, the slit 101 may be set to be 0.01mm-1.0mm, and the slit 101 may be correspondingly formed at other positions of the body of the hypotube 12, for example, at a position corresponding to one half of the proximal end of the hypotube 1 or three quarters of the proximal end, where the specific position is set according to the specific use.

In this embodiment, in order to ensure the connection stability between the pushing member 2 and the hypotube 1 after the pushing member extends into the cavity of the hypotube 1, the distance between the projection of the nearest end of the pushing member and the projection of the nearest end of the oblique slit in the axial direction of the cavity may be set to be larger than the distance between two adjacent slits, that is, as shown in fig. 3, the distance between the projection of the nearest end of the pushing member and the projection of the nearest end of the oblique slit in the axial direction of the cavity may be set to be L5, and the distance between the two slits may be set to be L6, where L5 is larger than L6.

The spacing between the proximal and distal slits 101 of the pusher member 2 may also be set at-5 mm-2mm for a particular application.

When the distance is negative, the nearest end of the pushing member 2 can pass through the slit at the far end after the pushing member 2 extends into the cavity, and is located between two adjacent slits, that is, the portion of the pushing member extending into the cavity falls into the projection plane formed by all the slits in the axial direction of the cavity, for example, the distance between the nearest end of the pushing member 2 and the slit 101 at the far end may be set to be 5mm.

When the spacing is positive, it is the most proximal end of the pusher 2 that, after it has been inserted into the cavity, is still at a distance from the most distal slit, i.e. the part of the pusher 2 that has been inserted into the cavity does not fall into the projection plane of all slits in the axial direction of the cavity.

When the distance is zero, i.e. the projection of the most proximal and the most distal slits 101 of the pusher 2 in the axial direction of the cavity is arranged in abutment, i.e. end-to-end connection.

Example 2:

this embodiment describes a catheter, see fig. 1 and 8, comprising an outer tube 4, an inner tube 5, a balloon, a seat 7 and a pushing structure, which pushing structure is the pushing structure described in embodiment 1, which pushing structure comprises a pushing member 2 and a hypotube 1, wherein the proximal end of the hypotube 1 is connected with the seat 7, the proximal end of the outer tube 4 is adapted to be connected with the distal end of the hypotube 1, i.e. the distal end of the hypotube 1 is extended into the cavity of the proximal end of the outer tube 4, the outer wall surface thereof abuts against the inner wall surface of the proximal end of the outer tube 4, the distal end of the outer tube 4 is adapted to be connected with the proximal end of the balloon, the inner tube 5 is arranged at a distance from the outer tube 4, the proximal end of the inner tube 5 extends to the through hole, the distal end thereof is adapted to extend out of the balloon in the axial direction of the balloon, the pushing member 2 is formed separately from the hypotube 1, and the proximal end thereof is adapted to be fixedly connected with the inner wall surface of the extension 102 of the distal end of the hypotube 1, the distal end of the inner tube 2 is adapted to extend in the axial direction 5 of the outer tube 4.

Under the action of external force, the hypotube 1 is suitable for applying propelling force to the outer tube 4, so that the outer tube 4 and the inner tube 5 push the balloon to carry and move to the focus distally, and the propelling structure has good stability and flexibility in the process of carrying and moving, and the catheter can stably carry the balloon to the focus, thereby being convenient for doctors to operate.

In this embodiment, a stress dispersing tube 6 is disposed between the hypotube 1 and the housing 7, one end of the stress dispersing tube 6 is connected to the housing 7, and is connected to the hypotube 1 by a sleeve, i.e., the stress dispersing tube 6 is sleeved on the proximal end of the hypotube 1.

It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the utility model.

Claims (12)

1. A propulsion structure comprising:

a hypotube (1) having a cavity with at least one end open;

the pushing piece (2) is formed by being separated from the hypotube (1), the cross-sectional area of the proximal end of the pushing piece (2) is larger than that of the distal end of the pushing piece, the proximal end of the pushing piece (2) is suitable for extending into the cavity, the pushing piece is fixedly connected with the inner wall surface of the distal cavity of the hypotube (1), and the distal end of the pushing piece (2) is suitable for extending along the distal end of the cavity in the axial direction.

2. Propulsion structure according to claim 1, characterized in that at least one welding spot (3) is formed between the propulsion element (2) and the hypotube (1), all welding spots (3) being arranged between the propulsion element (2) and the hypotube (1) at intersecting intervals.

3. A propulsion structure according to claim 2, characterized in that the distance between two adjacent welding spots (3) is set to 0.01-5 mm and the distance between the most distal welding spot (3) and the most distal end of the hypotube (1) is 0.5-2 mm.

4. A propulsion structure according to any of claims 1-3, characterized in that the distal opening of the hypotube (1) is formed with an oblique cut, the oblique cut being set at an angle of inclination of 40 ° -75 °.

5. The propulsion structure of claim 4, wherein the oblique incision is circular or oval.

6. The propulsion structure according to claim 4, characterized in that the distal end of the hypotube (1) further comprises an extension (102), the extension (102) being in smooth transition with the oblique incision, the proximal end of the propulsion member (2) being in abutment with at least the inner wall surface of the extension (102).

7. The propulsion structure according to claim 6, characterized in that the extension (102) has a U-shaped cross-section.

8. The propulsion structure according to claim 6, characterized in that it comprises at least a first uniform diameter section (201), a variable diameter section (202) and a second uniform diameter section (203) connected in a smooth transition along the proximal end to the distal end of the propulsion member (2), wherein the first uniform diameter section (201) and the hypotube (1) are fixedly connected, and the radial area of the proximal end of the variable diameter section (202) gradually decreases towards the distal radial area of the second uniform diameter section (203).

9. The propulsion structure according to claim 8, characterized in that the length ratio of the extension section (102) to the first uniform diameter section (201) is between 1:2-1:3; and/or the diameter of the second uniform diameter section (203) is 0.0508mm-0.1016mm; and/or the ratio of the length of the second uniform diameter section (203) to the length of the variable diameter section (202) is 1: 1.5-1:5.

10. A propulsion structure according to claim 4, characterized in that a number of slits (101) are provided around the circumference of the hypotube (1) at least in the distal part thereof, the distance between the projection of the nearest end of the propulsion element (2) and the nearest end of the oblique cut in the axial direction of the cavity being larger than the distance between two adjacent slits (101).

11. A pushing structure according to claim 10, characterized in that the distance between the most proximal and the most distal slits (101) of the pushing member (2) is-5 mm-2mm; and/or the slit (101) has a cut gap of 0.01mm-1.0mm.

12. A catheter, comprising:

a propulsion arrangement according to any one of claims 1-11.

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