CN116407382A

CN116407382A - Conveying system

Info

Publication number: CN116407382A
Application number: CN202111678715.9A
Authority: CN
Inventors: 唐江峰; 肖本好
Original assignee: Lifetech Scientific Shenzhen Co Ltd
Current assignee: Lifetech Scientific Shenzhen Co Ltd
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2023-07-11
Also published as: WO2023125010A1

Abstract

The invention discloses a conveying system, which comprises a handle, a sheath tube, a sheath core and a Tip head; the handle comprises a front handle and a rear handle which are axially arranged in a front-back opposite manner, and the rear handle can move back and forth relative to the front handle; the distal end of the sheath core is connected with the Tip head, and the proximal end extends into the handle; the sheath tube is coaxially sleeved outside the sheath core, and the proximal end of the sheath tube extends into the handle and is connected with the rear handle; in a first state that the distal end face of the sheath tube is attached to the Tip head, a reserved gap with the axial length of h1 exists between the front handle and the rear handle; when the back handle moves towards the front handle to reduce the reserved gap, the back handle drives the sheath tube so that the distal end face of the sheath tube is abutted against the Tip to be in a second state, and the sheath tube, the Tip and the back handle are axially and relatively fixed in the second state. The invention aims to solve the problem that the front end of a sheath tube is tilted relative to a Tip head step to scratch a blood vessel.

Description

Conveying system

Technical Field

The invention relates to the technical field of interventional medical instruments, in particular to a conveying system.

Background

The minimally invasive operation of vascular repair of the covered stent has the advantages of small wound, quick recovery and good immediate effect, and is widely applied to the treatment of aortic vascular diseases. During clinical implantation, the covered stent is preloaded into a sheath tube of a conveying system, conveyed to a lesion position through a conveying system through a vascular lumen of a human body, and then released from the sheath tube. The stent isolates the blood flow from the vascular lesion position, thereby achieving the purpose of treatment.

The stent delivery system is a carrier of the stent and is responsible for delivering the stent to the vascular lesion site, which is the key to immediate success of the operation. As shown in fig. 1, the conventional stent delivery system is generally composed of a sheath tube 2, a Tip head 4, a sheath core 3, a handle assembly 1, a screw assembly 5 and the like. The distal end of the sheath 2 is relatively engaged with the Tip 4 after the delivery system has been assembled and before sterilization, and the front and rear handles in the handle assembly 1 are also relatively engaged to form an initial first state. When the conveying system in the state is adopted, the front end of the attached sheath tube can tilt relative to the Tip head step to scratch the blood vessel in the conveying bending process. More seriously, since the sheath tube 2 in the delivery system is generally composed of three layers, as shown in fig. 2, an outer layer tube 2-3, an inner layer tube 2-1 and a middle layer spring tube 2-2 are respectively composed, wherein the outer layer tube 2-3 and the inner layer tube 2-1 are made of high-analysis materials, the middle layer spring tube 2-2 is made of metal materials, and a developing ring structure 2-4 is further arranged at the middle layer of the front end of the sheath tube 2. The middle spring tube 2-2 is a spiral metal spring, has a shrinkage tendency, and simultaneously the inner and outer polymer tubes are easy to expand with heat and contract with cold in the heating and cooling processes. After the conveying system is assembled with the bracket, sterilization treatment is needed, and the temperature of the sterilization process is generally far higher than the room temperature, so that the bracket system needs to be subjected to the processes of heating and cooling in the sterilization and analysis process. The sheath 2 is liable to have a gap W between the step of the Tip head 4 and the front end of the sheath 2 as shown in a partially enlarged portion in FIG. 3. When a gap W appears between the step of the Tip 4 and the front end of the sheath tube 2, the front end opening of the sheath tube 2 is tilted more in the pushing process of the conveying system in the bent blood vessel, the risk of scratching the blood vessel exists, and meanwhile, the gap also influences the attractiveness of the whole conveying system.

Disclosure of Invention

Based on the above, the invention provides a conveying system, which aims to solve the problem that the front end of a sheath tube is tilted relative to a Tip step to scratch a blood vessel.

To achieve the purpose, the invention adopts the following technical scheme:

the invention provides a conveying system, which comprises a handle, a sheath tube, a sheath core and a Tip head; the handle comprises a front handle and a rear handle which are axially arranged in a front-back opposite mode, and the rear handle can move back and forth relative to the front handle; the distal end of the sheath core is connected with the Tip head, and the proximal end of the sheath core extends into the handle; the sheath tube is coaxially sleeved outside the sheath core, and the proximal end of the sheath tube stretches into the handle and is connected with the rear handle; in a first state that the distal end face of the sheath tube is attached to the Tip head, a reserved gap with the axial length of h1 exists between the front handle and the rear handle; when the back handle moves towards the front handle to reduce the reserved gap, the back handle drives the sheath tube to enable the distal end face of the sheath tube to be abutted against the Tip head to be in a second state, and the sheath tube, the Tip head and the back handle are axially and relatively fixed in the second state.

In one embodiment, the Tip head comprises a first portion connected to the distal end of the sheath core and a second portion connected to the distal end of the first portion, the proximal diameter of the second portion being greater than the distal diameter of the first portion such that a step is formed at the connection of the second portion to the first portion, the step having a step face perpendicular to the axis of the sheath core; in the first state, the distal end face of the sheath tube is attached to the step face; in the second state, the distal end face of the sheath tube abuts against the step face.

In one embodiment, a wedge-shaped groove which is inclined relative to the axis of the sheath core is arranged at the connection part of the step surface and the first part, the distal end of the wedge-shaped groove is close to the axis of the sheath core, and the proximal end of the wedge-shaped groove is far away from the axis of the sheath core;

the sheath tube comprises a main body section and a connecting section coaxially connected to the far end of the main body section, wherein the outer periphery of the connecting section is obliquely arranged inwards, so that the outer periphery of the connecting section is wedge-shaped and is matched with the wedge-shaped groove;

the peripheral wedge shape of the connector segment guides the connector segment into the wedge-shaped recess during proximal movement of the sheath with the rear handle.

In one embodiment, the inner circumference of the connecting section is inclined inwards, and the inclination angles of the outer circumference and the inner circumference of the connecting section are equal, so that the caliber of the connecting section is smaller than the inner diameter of the main body section.

In one embodiment, the caliber of the connecting section is greater than or equal to the maximum diameter of the first portion.

In one embodiment, a portion of the outer peripheral surface of the first portion is inclined inwardly with respect to the axis of the sheath core such that the outer diameter thereof tapers from the proximal end to the distal end of the first portion.

In one embodiment, a portion of the outer peripheral surface of the first portion has an inclination angle of 1 ° or more and 5 ° or less with respect to the axis of the sheath core.

In one embodiment, the axial maximum depth of the wedge-shaped groove is greater than or equal to 0.5mm and less than or equal to 2mm.

In one embodiment, the proximal end of the sheath is connected with the rear handle by an axial fixed connection and an axial movable connection; when the proximal end of the sheath tube and the rear handle are axially fixed relatively, h1 is more than or equal to 2mm and less than or equal to 10mm; when the proximal end of the sheath tube is axially movably connected with the rear handle, the axial moving distance of the sheath tube relative to the rear handle is h2, and h1-h2 is more than or equal to 2mm and less than or equal to 10mm.

In one embodiment, a containing cavity is arranged in the handle, a sheath pipe joint is arranged in the containing cavity, the sheath pipe joint comprises an axial connecting part and a radial connecting part connected with the axial connecting part, and the proximal end of the sheath pipe extends into the containing cavity and is fixed relative to the axial connecting part; a clamping groove is formed in the cavity wall of the rear handle, and the radial connecting part extends into the clamping groove to realize that the proximal end of the sheath tube is connected with the rear handle; when the axial distance of the clamping groove is equal to the axial length of the radial connecting part, the proximal end of the sheath tube and the rear handle are axially and relatively fixed; when the axial distance of the clamping groove is larger than the axial length of the radial connecting part, the proximal end of the sheath tube is axially movably connected with the rear handle, and h2 is the maximum gap between the clamping groove and the radial connecting part.

In one embodiment, the clip groove has a hardness greater than the hardness of the sheath.

The conveying system is provided with the reserved gap between the front handle and the rear handle in the first state, the gap is reduced by moving the rear handle, and the sheath tube is driven to move, so that micro-extrusion and tight butting are realized between the distal end of the sheath tube and the tip, and a certain pretightening force is formed between the distal end of the sheath tube and the tip, so that the distal end of the sheath tube is prevented from being tilted by the pretightening force in the pushing process, and the blood vessel is prevented from being scratched. More importantly, the invention can also compensate the shrinkage of the sheath tube caused by heating and cooling through the reserved gap, so that the distal end of the sheath tube of the treated conveying system can still be abutted against the tip head, and the problem that the front end of the sheath tube is tilted to scratch a blood vessel caused by the gap is further avoided. Further, due to the design of the wedge-shaped grooves at the front end necking and the Tip step of the sheath in the conveying system, the front end of the sheath and the Tip step can be provided with larger pretightening force, the Tip step is not wrapped by the front end of the sheath, meanwhile, a reserved gap between the front handle and the rear handle is enlarged, larger sheath shortening deformation amount can be contained, risks caused by the gap are further reduced, and meanwhile, uncomfortable problems caused by differential shortening amount are reduced.

Drawings

FIG. 1 is a schematic cross-sectional structural view of a first state of the art conveyor system;

FIG. 2 is a schematic view of a partial cross-sectional structure of a sheath in a prior art delivery system;

FIG. 3 is a schematic cross-sectional view of a prior art conveyor system after heating and cooling and treatment;

FIG. 4 (a) is a schematic cross-sectional view of the first state of the conveying system of embodiment 1 of the present invention;

FIG. 4 (b) is a partial schematic view of the axially movable connection of the sheath connector to the rear handle;

FIG. 5 is a schematic cross-sectional view of a Tip head in a delivery system according to embodiment 1 of the present invention;

FIG. 6 is a schematic cross-sectional view of a sheath wrapped Tip head in a delivery system according to example 1 of the present invention;

FIG. 7 is a schematic cross-sectional view of the first state of the conveying system according to embodiment 2 of the present invention;

FIG. 8 is a schematic view in partial cross-section of a Tip head in a delivery system according to embodiment 2 of the present invention;

FIG. 9 is a schematic view in partial cross-section of a sheath in a delivery system according to example 2 of the present invention;

FIG. 10 is a schematic view in partial cross-section of a first portion of a Tip head in a delivery system according to embodiment 2 of the present invention;

fig. 11 is a schematic sectional view of the second state of the conveying system of embodiment 2 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only, and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "includes," "including," and "having" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless an order of performance is explicitly stated. It should also be appreciated that additional or alternative steps may be used.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

For ease of description, spatially relative terms, such as "inner," "outer," "lower," "below," "upper," "above," and the like, may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. Thus, the example term "below … …" may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions) and the spatial relative relationship descriptors used herein interpreted accordingly.

In the field of interventional medical devices, the end of a medical device implanted in a human or animal body or a delivery system for delivering the medical device, which is closer to an operator, is generally referred to as a "proximal end", the end farther from the operator is referred to as a "distal end", and the "proximal end" and the "distal end" of any component of the medical device or the delivery system are defined according to this principle. "axial" generally refers to the longitudinal direction of a medical device when delivered, and "radial" generally refers to the direction of the medical device perpendicular to its "axial" direction, and defines the "axial" and "radial" directions of any component of the medical device in accordance with this principle.

The invention provides a conveying system, which comprises a handle, a sheath tube, a sheath core and a Tip head; the handle comprises a front handle and a rear handle which are axially arranged in a front-back opposite manner, and the rear handle can move back and forth relative to the front handle; the distal end of the sheath core is connected with the Tip head, and the proximal end extends into the handle; the sheath tube is coaxially sleeved outside the sheath core, and the proximal end of the sheath tube extends into the handle and is connected with the rear handle, wherein the connection between the proximal end of the sheath tube and the rear handle comprises axial fixed connection or axial movable connection. The connection between the proximal end of the sheath tube and the rear handle in the radial direction is not limited, and the proximal end of the sheath tube and the rear handle can be rotated in the radial direction or fixed in the radial direction.

In the conveying system, in a first state, the distal end face of a sheath tube is attached to a Tip head, and a reserved gap with the axial length of h1 exists between a front handle and a rear handle. The adjacent contact fingers are not extruded. When the rear handle moves towards the front handle to reduce the reserved gap, the rear handle drives the sheath tube to enable the distal end face of the sheath tube to be abutted against the Tip to be in a second state, the distal end face of the sheath tube is pressed against the Tip in the second state, pretightening force exists between the distal end face of the sheath tube and the Tip, the sheath tube is in a micro-compression state, the sheath tube, the Tip and the rear handle are axially and relatively fixed, and the distal end face of the sheath tube is kept in the pressed against state with the Tip. Wherein the axial length h1 is greater than 0. It should be noted that, in the second state, the axial length h1 of the reserved gap between the front handle and the rear handle is greater than or equal to 0, and when h1=0, the distal end face of the sheath tube in the second state abuts against the Tip, meanwhile, no gap exists between the front handle and the rear handle, and the front handle and the rear handle are attached. When h1 is more than 0, the distal end face of the sheath tube in the second state is abutted against the Tip, and meanwhile, a gap still exists between the front handle and the rear handle, and the shrinkage of the sheath tube after the sheath tube is heated and cooled can be further compensated through the gap.

Wherein, when the proximal end of the sheath tube and the rear handle are axially fixed relatively, h1 is more than or equal to 2mm and less than or equal to 10mm; when the proximal end of the sheath tube is axially movably connected with the rear handle, the axial moving distance of the sheath tube relative to the rear handle is h2, and h1-h2 is more than or equal to 2mm and less than or equal to 10mm.

For example, referring to fig. 4 (a) and 4 (b), a receiving cavity is provided in the handle, a sheath tube joint 13 is provided in the receiving cavity, the sheath tube joint 13 includes an axial connecting portion 131 and a radial connecting portion 132 connected with the axial connecting portion 131, and a proximal end of the sheath tube 13 extends into the receiving cavity and is fixed relative to the axial connecting portion 131; a clamping groove 121 is formed in the cavity wall of the rear handle 12, and a radial connecting part 132 extends into the clamping groove 121 to realize connection of the proximal end of the sheath tube and the rear handle; wherein, when the axial distance m1 of the clamping groove 121 is equal to the axial length m2 of the radial connecting part 132, the proximal end of the sheath tube and the rear handle are axially fixed relatively; when the axial distance m1 of the clamping groove 121 is greater than the axial length m2 of the radial connecting portion 132, the proximal end of the sheath tube is axially movably connected with the rear handle, and h2 is the maximum gap between the clamping groove 121 and the radial connecting portion 132. Wherein, it can be understood that, in order to form the extrusion, when setting up the draw-in groove, the intensity and the hardness of draw-in groove are greater than the hardness of sheath pipe far away to guarantee that the sheath pipe is in the state of pretension extrusion.

Example 1

Referring to fig. 4 (a), the present invention illustratively provides a delivery system comprising a handle 10, a sheath 20, a sheath core 30, and a Tip head 40. In the first state of the first state, the distal end face of the sheath 20 is relatively attached to the Tip head 40, a reserved gap with an axial length h1 exists between the front handle 11 and the rear handle 12, wherein the axial length h1 of the reserved gap is greater than 0, so that the sheath can be moved to be in an abutting state when extrusion in the attaching state is called, preferably, the axial length h1 of the reserved gap is greater than or equal to the shrinkage of the sheath 20 after the delivery system is heated and cooled, so that the reserved gap can further compensate the shrinkage of the sheath caused by high-temperature cooling, and further, when the sheath is axially movably connected with the rear handle, the axial length h1 of the reserved gap is greater than or equal to the shrinkage of the sheath and the activity of axial movement of the sheath. So that when a gap exists between the step of the Tip head 40 and the front end of the sheath 20 after the delivery system is heated and cooled, the distal end face of the sheath 20 can be abutted against the Tip head 40 by the forward movement of the rear handle 12, and the reserved gap compensates the shortening amount caused by the heating and cooling of the sheath 20, so that the problem that the front end of the sheath 20 is tilted to scratch a blood vessel due to the gap is avoided.

Specifically, with continued reference to fig. 4 (a), the handle 10 includes a front handle 11 and a rear handle 12 disposed axially opposite to each other, a screw 14 is inserted into the rear handle 12, the front handle 11 is fixed relative to the screw 14, the rear handle 12 is movable on the screw 14 forward and backward relative to the front handle 11, i.e. the front handle 11 is located at a distal end, and the rear handle 12 is located at a proximal end. The handle 10 is provided with a containing cavity, the containing cavity of the rear handle 12 is provided with a sheath pipe joint 13 for connecting the sheath pipe 20, and the sheath pipe joint 13 and the rear handle 12 are axially fixed relatively, so that the sheath pipe 20 connected with the rear handle 12 through the sheath pipe joint 13 can move after the axial movement of the handle 12. Alternatively, the sheath tube 13 may extend partially beyond the rear handle 12 and be rotatable relative to the rear handle 12 so that the sheath tube 20 rotates as the sheath tube 13 rotates. The manner in which the sheath 20 is connected to the rear handle 12 is not limited thereto. In the first state of the conveying system, as shown in fig. 1, the front handle and the rear handle are abutted against each other, and no gap exists between the front handle and the rear handle, while in the conveying system of this embodiment, as shown in fig. 4 (a), a reserved gap with an axial length h1 exists between the front handle 11 and the rear handle 12, and the amount of shrinkage caused by heating and cooling of the sheath 20 is compensated by the reserved gap.

The axial length h1 of the clearance between the front handle 11 and the rear handle 12 is not too long or too short. The reason is that: h1 is too short to completely counteract the amount of shrinkage of the sheath 20 through the sterilization process, so that gaps remain after compensation. h1 is too long, after the rear handle 12 is moved to be closed with the front handle 11, the force applied to the step of the Tip head 40 by the front end of the sheath 20 is larger, and as the front end of the sheath 20 is a thin-wall polymer tube, the continuous force is easy to deform to form a horn mouth, so that the step of the Tip head 40 is completely wrapped, as shown in fig. 6. When Tip head 40 is wrapped by sheath 20, it may cause difficulty in the operation of venting the preoperative stent system, affecting the normal operation. In view of this, in this embodiment, when the proximal end of the sheath tube and the rear handle are axially fixed relatively, 2 mm.ltoreq.h1.ltoreq.5mm; when the proximal end of the sheath tube is axially movably connected with the rear handle, the axial moving distance of the sheath tube relative to the rear handle is h2, and h1-h2 is more than or equal to 2mm and less than or equal to 5mm.

With continued reference to fig. 4 (a), the distal end of the sheath core 30 is connected to the Tip head 40, and the proximal end of the sheath core 30 extends into the handle 10 and out of the handle 10. The sheath 20 is coaxially sleeved outside the sheath core 30, and the proximal end of the sheath 20 extends into the handle 10 and is connected with the rear handle 12 through the sheath connector 13, so that the sheath 20 can axially move along the handle 12; in the first state of the delivery system, when the distal end face of the sheath 20 is in opposition to the Tip head 40, there is a clearance gap of axial length h1 as described above between the front handle 11 and the rear handle 12.

Illustratively, as an embodiment in which the distal end face of the sheath 20 is relatively fitted to the Tip 40, as shown in fig. 4 (a) and 5, the Tip 40 includes a first portion 41 connected to the distal end of the sheath core 30 and a second portion 42 axially connected to the distal end of the first portion 41, the proximal end diameter of the second portion 42 being larger than the distal end diameter of the first portion 41, so that a step is formed at the connection of the second portion 42 to the first portion 41, the step having a stepped face 40a perpendicular to the axis X of the sheath core 30, the distal end of the sheath 20 being fitted around the outer circumference of the first portion 41 after the fitting is completed, and the distal end face of the sheath 20 being relatively fitted to the stepped face 40 a.

Wherein the first portion 41 comprises a connected guiding section 41a and a socket section 41b. The guiding section 41a is located at the proximal end, the sleeving section 41b is located at the distal end, and the peripheral outline of the guiding section 41a is contracted towards the sheath core 30, so that the distal end of the guiding sheath 20 is conveniently sleeved on the sleeving section 41b. Likewise, to facilitate guiding of the Tip 40 into the vessel by the delivery system, the distal end of the distally located second portion 42 is contracted toward the sheath core 30 such that its entry end is approximately tapered. Further, the radial thickness of the step is equal to the wall thickness of the sheath 20, so that the maximum outer peripheral surface of the second portion 42 is flush with the outer peripheral surface of the sheath 20 sleeved on the first portion 41, which is convenient for scratching the wall of the blood vessel during the process of entering the blood vessel by the delivery system.

The conveying system of the embodiment can ensure that the end part of the sheath tube is propped against the Tip head by arranging the reserved gap between the front hand and the rear hand, and can also compensate the shortening amount caused by the temperature rise and the cooling of the sheath tube, so that the sheath tube can be propped against the Tip head before and after treatment, and the problem that the front end of the sheath tube 20 is tilted to scratch the blood vessel is avoided.

Example 2

In the practical design process, it is found that the density consistency of the spring tube of the sheath tube 20 is difficult to ensure, meanwhile, the inner and outer polymer tubes have certain difference, the variation of the shrinkage is larger after the sterilization process, and the axial length h1 of the reserved gap between the front handle 11 and the rear handle 12 is not well determined. If the reservation is too small, as shown in fig. 3, a gap still exists after the front handle 11 and the rear handle 12 are closed, so that the problem of scratching the blood vessel by tilting the front end of the sheath still exists. However, if the reservation is too large, there is a problem that the Tip head 40 is wrapped by the sheath 20 as shown in fig. 6, resulting in difficulty in the exhaust operation, and in view of this, this embodiment is further improved on the basis of embodiment 1.

Referring to fig. 7 and 8, in the present embodiment, on the basis of embodiment 1, a wedge-shaped groove 40a1 inclined with respect to the axis X of the sheath core 30 is provided at the junction of the stepped surface 40a and the first portion 41, the distal end of the wedge-shaped groove 40a1 is close to the axis X of the sheath core 30 and the proximal end thereof is deviated from the axis X of the sheath core 30, and the inclined wedge-shaped groove 40a1 is intended to guide the sheath 20 into the sheath 20 on the one hand and to enable the sheath 20 to be axially inserted into the Tip head 40 to be engaged with the Tip head 40 on the other hand, and the Tip head 40 can restrict the distal end of the sheath 20. Preferably, the wedge-shaped recess 40a1 is connected to the first portion 41. In addition, under the condition that the initial assembly is not processed, the distal end face of the sheath 20 is still relatively attached to the step face 40a of the Tip head 40, so the step comprises two parts in the radial direction, the wedge-shaped groove 40a1 is arranged close to the inner side, the periphery of the wedge-shaped groove 40a1 comprises a circle of abutting face 40a2, the joint of the abutting face 40a2 and the wedge-shaped groove 40a1 can adopt smooth transition, and the distal end of the sheath 20 can smoothly slide into the wedge-shaped groove 40a1 when being pushed axially when being abutted against the abutting face 40a2, so that the Tip head 40 is prevented from being wrapped by a horn mouth. Preferably, since the Tip 40 is injection molded, in order to avoid causing difficulty in demolding the Tip 40, the axial maximum depth S of the wedge-shaped groove 40a1 is 0.5mm or more and 2mm or less as shown in fig. 8.

Referring to fig. 7 and 9, based on the above-described arrangement of the wedge-shaped groove 40a1, the distal end of the sheath 20 is arranged in a wedge shape that mates with the wedge-shaped groove 40a1, thereby facilitating the distal end of the sheath 20 to enter the wedge-shaped groove 40a1. Specifically, the sheath 20 includes a main body section 21 and a connection section 22 coaxially connected to a distal end of the main body section 21, the connection section 22 is located at an end of the main body section 21, and has a relatively small length, and an outer circumference of the connection section 22 is obliquely arranged in an inner direction, so that the outer circumference of the connection section 22 is in a wedge shape matched with the wedge-shaped groove 40a1, during a process of moving the sheath 20 towards a proximal end, the connection section 22 is pressed by the handle 12, and is guided by the connection section 22 to slide into the wedge-shaped groove 40a1 by the outer surface Zhou Xiexing thereof, and a wedge-shaped surface of the wedge-shaped groove 40a1 abuts against an outer circumference wedge-shaped surface of the connection section 22 to form surface contact.

Further, with continued reference to fig. 7 and 9, since the front end of the sheath 20 is a thin-walled polymer tube, the difficulty of setting a wedge shape adapted to the wedge-shaped groove 40a1 on the outer periphery of the thin-walled tube is great, and for this reason, the inner periphery of the connecting section 22 is also inclined inwards in this embodiment, and the inclination angles of the outer periphery and the inner periphery of the connecting section 22 are equal, so that the whole connecting section 22 is inclined with respect to the main section 21, and in the implementation process of the process, the existing connecting section 22 inclined with respect to the main section 21 can be formed by slightly bending and heat setting the front end of the thin-walled sheath 20, so that the process difficulty and cost are greatly reduced. It will be appreciated that, due to the inward bending of the connecting section 22 at the distal end of the sheath 20, the caliber D1 of the connecting section 22 is slightly smaller than the inner diameter of the main section 21, and to ensure that the sheath 20 can be sleeved on the first portion 41 of the Tip head 40, as further shown in fig. 10, it is required that the caliber D1 of the connecting section 22 is greater than or equal to the maximum diameter D2 of the first portion 41. If the diameter D1 of the connecting section 22 is smaller than the maximum diameter D2 of the first portion 41, the assembly is difficult, and the stent releasing force may be increased. It should be noted that when the first portion 41 has the guide section 41a and the socket section 41b, it is required that the caliber D1 of the connection section 22 must be equal to or greater than the maximum diameter D2 of the socket section 41b. The maximum diameter is used here because when the outer surface of the socket section 41b is flush, i.e., the outer peripheral surface is not inclined with respect to the axis X of the sheath core 30, the diameters of the sections on the socket section 41b are all equal, and the maximum diameter is equal to the actual radial length thereof. However, when the outer surface of the socket section 41b is disposed non-flush, i.e., the outer peripheral surface is disposed obliquely with respect to the axis X of the sheath core 30, the radial lengths of the sections on the socket section 41b are not equal, wherein a maximum diameter is necessarily present, and when the caliber D1 of the connection section 22 must be equal to or greater than the maximum diameter of the first portion 41, then the necessary connection section 22 is allowed to pass through the first portion 41 so that the sheath 20 is sleeved on the first portion 41 of the Tip head 40.

As shown in fig. 10 and 11, since the thickness t of the step of the Tip 40 is matched with the wall thickness of the sheath 20, that is, the radial height of the step of the Tip 40 is equal to the wall thickness of the sheath 20, when the connecting section 22 of the sheath 20 is bent inwards, the bent Tip of the connecting section 22 abuts against the first portion 41 when the sheath 20 is sleeved on the first portion 41, the outer diameter of the sheath 20 is higher than the outer diameter of the Tip 40, and the Tip and the sheath are not flush, so that the higher portion can scratch the wall of a blood vessel. Therefore, in order to ensure that the Tip head 40 outer periphery is flush with the sheath 20 outer periphery as much as possible, on the basis of the above, a part of the outer peripheral surface of the first portion 41 is inclined inward with respect to the axis X of the sheath core 30 such that the outer diameter thereof gradually decreases from the proximal end to the distal end of the first portion 41. Preferably, a part of the outer circumferential surface of the socket section 41b in the first portion 41 is inclined inwardly with respect to the axis X of the sheath core 30, and at this time, the side wall of the wedge-shaped groove 40a1 near the axis X of the sheath core 30 is also inclined inwardly with respect to the axis X of the sheath core 30 by an angle α such that the outer diameter thereof gradually decreases from the proximal end to the distal end thereof, thereby smoothly transitionally connecting the side wall of the wedge-shaped groove 40a1 near the axis X of the sheath core 30 with the distal end of the socket section 41b of the first portion 41, thereby increasing the size of the wedge-shaped groove 40a1 at the step of the Tip head 40. After the bent connecting section 22 slides into the wedge-shaped groove 40a1, when the caliber outline of the connecting section 22 is abutted against the side wall of the wedge-shaped groove 40a1, which is close to the axis X of the sheath core 30, the periphery of the Tip head 40 is flush with the periphery of the sheath tube 20, so that the smoothness of the outer surface of the opposite joint of the Tip head 40 and the sheath tube 20 is ensured, the smooth entering of a conveying system into a blood vessel is facilitated, and the scratch of the blood vessel is avoided. In addition, referring to fig. 10, the partial outer peripheral surface of the socket section 41b of the first portion 41 in this embodiment is inclined inwardly with respect to the axis X of the sheath core 30, which means that the partial outer peripheral surface of the socket section 41b near the distal end is positioned in parallel with the axis X of the sheath core 30 while the rest of the outer peripheral surface of the socket section 41b near the proximal end is still positioned in parallel with respect to the axis X of the sheath core 30, that is, the socket section 41b includes an inclined section and a non-inclined section at the proximal end, which is positioned so that the sheath port, which is small in front of being pressed, can be enlarged when the sheath is withdrawn, thereby reducing the resistance of the sheath acting on the stent and reducing the release force of the stent.

Preferably, the inclination angle α of the outer peripheral surface of the first portion 41 with respect to the axis X of the sheath core 30 cannot be too large nor too small; the inclination angle α is too large, and since the Tip 40 is injection molded, it is difficult to mold the Tip 40, and the inclination angle α is too small, so that it is not possible to effectively ensure that the outer diameter of the sheath 20 is flush with the outer diameter of the Tip 40 after the sheath is sleeved, and in this regard, the inclination angle α of the outer peripheral surface of the first portion 41 with respect to the axis X of the sheath core 30 is 1 ° or more and 5 ° or less, which not only satisfies the requirement of flush with the outer periphery, but also does not cause great difficulty in mold release of the Tip 40.

Based on the arrangement of the above-described structure, the axial length h1 of the reserve gap existing between the front handle 11 and the rear handle 12 of the present embodiment can be designed to be larger. In the embodiment, when the proximal end of the sheath tube and the rear handle are axially fixed relatively, h1 is more than or equal to 2mm and less than or equal to 10mm; when the proximal end of the sheath tube is axially movably connected with the rear handle, the axial moving distance of the sheath tube relative to the rear handle is h2, and h1-h2 is more than or equal to 2mm and less than or equal to 10mm. Referring to fig. 11, after the front handle 11 and the rear handle 12 are closed, the sheath 20 is pressed along the direction of the wedge-shaped groove 40a1 of the Tip head 40, and the connection section 22 at the front end of the sheath 20 is contracted inwards into the wedge-shaped groove 40a1, without being expanded outwards to wrap the Tip head 40.

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

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

Claims

1. A conveying system is characterized by comprising a handle, a sheath tube, a sheath core and a Tip head; the handle comprises a front handle and a rear handle which are axially arranged in a front-back opposite mode, and the rear handle can move back and forth relative to the front handle; the distal end of the sheath core is connected with the Tip head, and the proximal end of the sheath core extends into the handle; the sheath tube is coaxially sleeved outside the sheath core, and the proximal end of the sheath tube stretches into the handle and is connected with the rear handle; in a first state that the distal end face of the sheath tube is attached to the Tip head, a reserved gap with the axial length of h1 exists between the front handle and the rear handle; when the back handle moves towards the front handle to reduce the reserved gap, the back handle drives the sheath tube to enable the distal end face of the sheath tube to be abutted against the Tip head to be in a second state, and the sheath tube, the Tip head and the back handle are axially and relatively fixed in the second state.

2. The delivery system of claim 1, wherein the Tip head comprises a first portion connected to the distal end of the sheath core and a second portion connected to the distal end of the first portion, the second portion having a proximal diameter greater than the distal diameter of the first portion such that a step is formed at the connection of the second portion to the first portion, the step having a step surface perpendicular to the axis of the sheath core; in the first state, the distal end face of the sheath tube is attached to the step face in a relative manner; in the second state, the distal end face of the sheath tube abuts against the step face.

3. The delivery system of claim 2, wherein the junction of the stepped surface and the first portion is provided with a wedge-shaped recess inclined relative to the axis of the sheath core, the wedge-shaped recess having a distal end proximal to the axis of the sheath core and a proximal end distal to the axis of the sheath core;

4. A delivery system according to claim 3, wherein the inner circumference of the connecting section is inclined inwardly, and the outer circumference of the connecting section is inclined at an equal angle to the inner circumference such that the bore of the connecting section is smaller than the inner diameter of the main section.

5. The delivery system of claim 4, wherein the connecting section has a caliber greater than or equal to a maximum diameter of the first portion.

6. The delivery system of claim 5, wherein a portion of the outer peripheral surface of the first portion is inclined inwardly relative to the axis of the sheath core such that the outer diameter thereof tapers from the proximal end to the distal end of the first portion.

7. The delivery system of claim 6, wherein a portion of the peripheral surface of the first portion is inclined at an angle of 1 ° or more and 5 ° or less relative to the axis of the sheath core.

8. A conveying system according to claim 3, wherein the axial maximum depth of the wedge-shaped groove is 0.5mm or more and 2mm or less.

9. The delivery system of any one of claims 1-8, wherein the proximal end of the sheath is connected to the rear handle comprises an axially fixed connection or an axially movable connection; when the proximal end of the sheath tube and the rear handle are axially fixed relatively, h1 is more than or equal to 2mm and less than or equal to 10mm; when the proximal end of the sheath tube is axially movably connected with the rear handle, the axial moving distance of the sheath tube relative to the rear handle is h2, and h1-h2 is more than or equal to 2mm and less than or equal to 10mm.

10. The delivery system of claim 9, wherein a receiving cavity is provided in the handle, a sheath connector is provided in the receiving cavity, the sheath connector includes an axial connection portion and a radial connection portion connected to the axial connection portion, and a proximal end of the sheath extends into the receiving cavity and is fixed relative to the axial connection portion; a clamping groove is formed in the cavity wall of the rear handle, and the radial connecting part extends into the clamping groove to realize that the proximal end of the sheath tube is connected with the rear handle; when the axial distance of the clamping groove is equal to the axial length of the radial connecting part, the proximal end of the sheath tube and the rear handle are axially and relatively fixed; when the axial distance of the clamping groove is larger than the axial length of the radial connecting part, the proximal end of the sheath tube is axially movably connected with the rear handle, and h2 is the maximum gap between the clamping groove and the radial connecting part.

11. The delivery system of claim 10, wherein the clip groove has a hardness greater than a hardness of the sheath.