CN110755185A

CN110755185A - Conveying system

Info

Publication number: CN110755185A
Application number: CN201810844970.8A
Authority: CN
Inventors: 张军强; 王刚
Original assignee: Lifetech Scientific Shenzhen Co Ltd
Current assignee: Lifetech Scientific Shenzhen Co Ltd
Priority date: 2018-07-27
Filing date: 2018-07-27
Publication date: 2020-02-07

Abstract

The invention discloses a conveying system, which comprises an inner core pipe, a sheath pipe and an end head, wherein the sheath pipe is sleeved outside the inner core pipe and can axially move relative to the inner core pipe, the end head is connected to the inner core pipe and is communicated with a pipe cavity of the inner core pipe, the end head comprises a guide part and a sleeving part which are smoothly connected, and the sleeving part is connected to the inner core pipe; the outer surface of the sleeve part is a flat surface, and the diameter of a circumcircle of the cross section of the sleeve part is smaller than the inner diameter of the sheath pipe. The invention has the beneficial effects that: because the end includes the guide part and the registrate portion of smooth connection, and the outer peripheral face of registrate portion is for leveling the surface, can effectively avoid appearing the not smooth and easy phenomenon of percutaneous puncture in the clinical operation process and taking place to withdrawing from conveying system external in-process, registrate portion can not produce the scraping to the pipe chamber support, and then improves the accuracy nature of support location.

Description

Conveying system

Technical Field

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

Background

With the continuous development of interventional technology, the advantages of using the lumen stent to treat aortic aneurysm and arterial dissection diseases are prominent day by day. This treatment is specifically as follows: firstly, compressing the lumen stent into a sheath of a delivery system; secondly, puncturing a blood vessel at the femoral artery, the iliac artery or other positions, and establishing a track in the blood vessel by using a guide wire; then, one end of the conveying system enters the human body along the guide wire, and the lumen stent is released to the lesion position; finally, the guide wire and the delivery system are withdrawn, and the interventional treatment of the aneurysm and the arterial dissection is completed.

A conventional lumen stent delivery system is shown in fig. 1, and the delivery system 10 includes an inner core tube 11, a sheath tube 12 covering the inner core tube 11 and used for accommodating the lumen stent, and a tip 13 connected to a distal end of the inner core tube 11. Wherein, the outer peripheral surface of the proximal end of the tip 13 is provided with a step structure 14, and after the lumen stent is compressed into the sheath 12 of the delivery system, the sheath 12 is abutted to the step structure 14.

Because the head 13 of the conveying system with the structure is provided with the stepped structure 14, the height of the stepped structure 14 along the radial direction of the head 13 is generally larger than 1mm, after the lumen stent is completely released, in the process of withdrawing the conveying system out of the body, the stepped structure 14 on the head 13 can scrape the lumen stent, even the stent is displaced, and the accuracy of stent positioning is reduced. Moreover, for the stent with the barb structure, if the stent is displaced, the barb structure can injure the vascular tissue, thereby causing the risk of failure of clinical operation.

In addition, after the luminal stent is compressed into the sheath 12 of the delivery system, if there is a gap between the sheath 12 and the tip 13 in the axial direction, the delivery system is likely to have a phenomenon of unsmooth percutaneous puncture. As shown in fig. 2, if there is an axial gap between the distal end surface of the sheath 12 and the step structure 14, the delivery system may scrape the vascular tissue 20 during the percutaneous puncture procedure, resulting in a non-smooth puncture procedure. However, since the sheath 12 is mostly made of a polymer material, the sheath 12 is shortened to some extent during the high-temperature sterilization, and therefore, even if the distal end surface of the sheath 12 is brought into contact with the stepped structure 14 during the assembly, the sheath 12 is shortened during the high-temperature sterilization of the entire delivery system, the distal end surface of the sheath 12 is separated from the stepped structure 14, and further, the occurrence of the unsmooth percutaneous puncture during the clinical operation is caused. In addition, since the delivery system is subjected to a certain degree of jolt during transportation and storage, the distance between the distal end face of the sheath 12 and the stepped structure 14 may be further increased.

Disclosure of Invention

The present invention is directed to a conveying system, which overcomes the above-mentioned shortcomings in the prior art.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the utility model provides a conveying system, include inner core pipe, cover in the outer just can be relative of inner core pipe axial displacement's sheath pipe, and connect in on the inner core pipe and with the end that the lumen of inner core pipe is linked together, the end includes smooth guide part and the registrate portion of connecting, the registrate portion is connected to the inner core pipe, the outer peripheral face of registrate portion is roughly smooth surface, the circumscribed circle diameter of the biggest cross section of registrate portion is less than the internal diameter of sheath pipe.

In the delivery system of the present invention, a difference between an inner diameter of the sheath and a diameter of a circumscribed circle of a maximum cross-section of the nesting portion is less than or equal to 2 mm.

In the conveying system, the outer diameter of the far end of the nesting part is not smaller than the outer diameter of the near end, and the included angle between the generatrix of the nesting part and the longitudinal central line of the nesting part is not more than 8 degrees.

In the delivery system of the present invention, the engaging portion comprises a fixing cap, and the fixing cap comprises a sleeve and a connecting member connected to a distal end of the sleeve; the connecting piece is of a hollow structure, the diameter of an inner cavity of the connecting piece is larger than the inner diameter of the inner core pipe, and the diameter of a circumscribed circle of the largest surface of the connecting piece is smaller than the outer diameter of the sleeve.

In the conveying system of the invention, the nesting part further comprises a transition part connected with the connecting piece.

In the delivery system according to the invention, the fixing cap is connected to the transition portion or the guide portion by injection molding.

In the delivery system of the present invention, an anchoring device is provided on the connecting member.

In the delivery system of the present invention, the delivery system further comprises a fixing anchor connected to the distal end of the outer core tube, and a push tube located between the outer core tube and the sheath tube; the fixing anchor comprises an inserting part and a supporting part which are connected, and the supporting part is fixedly connected with the outer core pipe; when the fixing anchor is folded with the nesting portion, the inserting portion is inserted into the sleeve, and the abutting portion abuts against the nesting portion.

In the conveying system, at least one positioning groove is arranged on the outer peripheral surface of the fixed anchor, the positioning groove penetrates through the proximal end face of the abutting part, and a first positioning piece for hooking the wave crest of the bare support is arranged in the positioning groove on the inserting part.

In the conveying system of the present invention, the first positioning member includes a first boss and a second boss, and the wave peak is hooked between the first boss and the second boss.

In summary, the conveying system of the invention has the following advantages: because the end of this application includes smooth guide part and the registrate portion of connecting, and the outer peripheral face of registrate portion is roughly smooth surface, in with lumen support compression advance conveying system's sheath intraductal back, make the sheath pipe box establish outside this registrate portion, can not form the clearance along axial direction between registrate portion and the sheath pipe yet, effectively avoid appearing the unsmooth phenomenon of percutaneous puncture in the clinical operation process and take place. And because the end head comprises the smoothly connected guide part and the sleeving part, and the peripheral surface of the sleeving part is a flat surface, when the lumen stent is completely released, the sleeving part cannot scrape the lumen stent in the process of withdrawing the conveying system out of the body, and the accuracy of stent positioning is further improved.

Drawings

The invention will be further described with reference to the accompanying drawings and examples, in which:

FIG. 1 is a schematic view of a prior art delivery system;

FIG. 2 is a schematic view of the delivery system of FIG. 1 scraping vascular tissue during a clinical procedure;

FIG. 3 is a schematic view of a delivery system provided by an embodiment of the present invention;

FIG. 4 is a schematic view of the sheath of the delivery system of FIG. 3 fully covering the hub;

FIG. 5 is a schematic view of a sheath covering portion of the hub of the delivery system of FIG. 3;

FIG. 6 is a schematic view of the delivery system of FIG. 3 releasing a luminal stent;

FIG. 7 is a cross-sectional view of the tip of the delivery system of FIG. 3;

FIG. 8 is a schematic view of the delivery system of FIG. 3 with the anchor inserted into the head;

FIG. 9 is a schematic view of a retaining cap of the delivery system of FIG. 3;

fig. 10 is a schematic view of a tie-down anchor of the delivery system of fig. 3.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather should be construed as broadly as the present invention is capable of modification in various respects, all without departing from the spirit and scope of the present invention.

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

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

In the field of interventional medicine, it is generally defined that the end of the instrument proximal to the operator is the proximal end and the end distal to the operator is the distal end.

Referring to fig. 3, the present invention provides a delivery system 100 for delivering implantable medical devices such as luminal stents, valves, occluders, and the like. The delivery system includes an inner core tube 110, a sheath tube 130 that is sleeved outside the inner core tube 110 and is axially movable relative to the inner core tube 110, and a tip 140 that is connected to a distal end of the inner core tube 110. When the sheath tube 130 is sleeved outside the core tube 110, the compressed or stretched implantation instruments such as the lumen stent, the valve, the occluder, etc. are accommodated between the sheath tube 130 and the core tube 110. The tip 140 is a hollow structure, and the inner cavity of the tip 140 is communicated with the lumen of the inner core tube 110 to serve as a guide wire channel.

The tip 140 includes a smoothly connected guiding portion 141 and a sleeve portion 142, and the sleeve portion 142 is directly and fixedly connected to the distal end of the inner core tube 110. The outer peripheral surface of the fitting portion 142 is substantially a flat surface, and the circumscribed diameter of the maximum cross section of the fitting portion 142 is smaller than the inner diameter of the sheath 130. The phrase "the outer peripheral surface of the engaging portion 142 is substantially flat" means that the outer peripheral surface of the engaging portion 142 may be provided with holes, grooves or protrusions having a small radial height, and the outer peripheral surface of the engaging portion 142 is substantially flat as long as the height difference between the point of the protrusion farthest from the longitudinal central axis and the point of the protrusion closest to the longitudinal central axis is not greater than 0.5 mm.

During assembly, after the implanting device such as a lumen stent, a valve, an occluder, etc. is compressed into the sheath tube 130 of the delivery system, the sheath tube 130 is sleeved outside the sheathing part 142. It is understood that when the sheath 130 is sleeved outside the nesting portion 142, the sheath 130 may cover the nesting portion 142 completely (as shown in fig. 4) or may cover only a part of the nesting portion 142 (as shown in fig. 5). Because the outer peripheral surface of the fitting portion 142 is a flat surface, even if the sheath tube 130 is sleeved outside a part of the fitting portion 142, a gap along the axial direction as shown in fig. 2 is not formed between the fitting portion 142 and the sheath tube 130, thereby effectively avoiding the occurrence of the phenomenon of unsmooth percutaneous puncture in the clinical operation process. Moreover, because the outer peripheral surface of the sheathing part 142 is a flat surface, after the lumen stent is completely released, the sheathing part 142 does not scrape the implantation instrument or the inner wall of the blood vessel in the process of withdrawing the conveying system out of the body, thereby improving the positioning accuracy of the implantation instrument.

Furthermore, the far end of the sheath 130 can be subjected to thermal shrinkage treatment, so that the far end face of the sheath is in smooth transition with the outer wall surface of the sheath, and the sharp cross section of the far end of the sheath 130 is avoided.

Because the sheath 130 is mostly made of a polymer material or a composite material composed of a polymer material and a metal material, the sheath 130 is shortened to a certain extent during the high-temperature sterilization process, and if the overlapping area of the sheath 130 and the sheathing part 142 is small, the sheath 130 is shortened, the sheath 130 and the sheathing part 142 are easily separated, so that a gap along the axial direction is generated between the sheath 130 and the sheathing part 142, and further, the occurrence of a phenomenon of unsmooth percutaneous puncture during the clinical operation process is caused. In addition, the delivery system 100 may experience a degree of jolt during transport and storage, which may further increase the distance between the sheath 130 and the nest 142. Therefore, in the delivery system, the overlapping length of the sheath 130 and the sleeve portion 142 along the axial direction is not less than 1mm, preferably not less than 3mm, during percutaneous puncture.

It will be appreciated that when the sheath 130 is disposed over the sheath portion 142, the smaller the radial gap between the sheath 130 and the sheath portion 142, the less resistance the delivery system 100 experiences during percutaneous penetration. Therefore, the difference between the inner diameter of the sheath tube 130 and the diameter of the circumscribed circle of the cross section of the sleeve portion 142 is 0 to 2mm, preferably 0 to 1 mm.

In the illustrated embodiment, the engaging portion 142 is a hollow cylindrical structure, and it should be understood that in other embodiments, the engaging portion 142 may also be another structure, such as a hollow circular truncated cone structure, as long as the outer peripheral surface of the engaging portion 142 is substantially a flat surface and the inner diameter of the sheath 130 is not smaller than the outer diameter of the maximum cross section of the engaging portion 142.

When the engaging portion 142 is a hollow circular truncated cone structure, the diameter of the proximal end surface of the engaging portion 142 is smaller than the diameter of the distal end surface, so as to facilitate the sheathing of the sheath tube 130 outside the engaging portion 142 during assembly. At this time, if the included angle between the generatrix of the fitting portion 142 and the axis of the fitting portion 142 is not more than 8 °, and if the included angle is more than 8 °, when the sheath 130 covers only a part of the fitting portion 142, the gap between the sheath 130 and the fitting portion 142 in the radial direction is too large, which may affect the puncture.

Further, in order to facilitate the sheath tube 130 to be sleeved outside the sheathing part 142, a rounded corner structure is disposed on a proximal end surface of the sheathing part 142.

The guiding portion 141 is made of a polymer material with good flexibility, has good bending performance, and can pass through a complex bent blood vessel along with a guide wire. Preferably, the outer circumferential surface of the guide portion 141 is also a flat surface to reduce resistance during puncturing.

In the illustrated embodiment, the guide portion 141 is generally frustoconical in configuration with a distal end surface having a diameter less than a diameter of the proximal end surface. It is understood that the smaller the diameter of the proximal end surface of the guide part 141 is, the more convenient the doctor performs the vascular puncture during the clinical procedure, but the too small diameter of the proximal end surface of the guide part 141 is, which easily punctures the vascular tissue during the puncture procedure. Preferably, the diameter of the proximal end surface of the guide part 141 is 1.5mm to 2.5 mm.

Referring again to fig. 3, the delivery system 100 further includes an outer core tube 120 disposed between the inner core tube 110 and the sheath tube 140 and axially movable with respect to the inner core tube 110, a fixed anchor 150 connected to a distal end of the outer core tube 120, and a push tube 160 disposed between the outer core tube 120 and the sheath tube 130. When the sheath tube 130 is sleeved outside the outer core tube 120, an annular cavity is formed between the sheath tube 130 and the outer core tube 120, and the compressed lumen stent is accommodated in the annular cavity. Referring to fig. 6, the luminal stent 200 comprises a covered stent 210 and a bare stent 220 connected to one end of the covered stent 210, the bare stent 220 is hooked on the fixed anchor 150, and the other end of the covered stent 210 abuts against the distal end surface of the push tube 160, so that the luminal stent is axially compressed between the fixed anchor 150 and the push tube 160.

As shown in fig. 7 and 8, the proximal end surface of the engaging portion 142 is provided with a limiting groove 143. During assembly, the fixing anchor 150 connected with the bare bracket 220 is inserted into the limiting groove 143, so that the bare bracket 220 is radially limited between the fixing anchor 150 and the limiting groove 143, and then the sheath 130 is sleeved outside the sheathing part 142. Because the luminal stent 200 is entirely constrained within the sheath 130, the luminal stent 200 and the delivery system 100 can remain relatively stationary until the lesion site is reached. After the delivery system 100 loaded with the luminal stent 200 reaches the lesion, the luminal stent 200 is released. In the releasing process of the stent, the sheath tube 130 is firstly retracted, so that the covered stent 210 is released, the bare stent 200 is still limited between the fixed anchor 150 and the limiting groove 143, after the covered stent 210 is released, the inner core tube 110 is pushed to move forwards, the inner core tube 110 drives the end head 140 to move forwards axially, so that the fixed anchor 150 is separated from the limiting groove 143, the radial constraint of the bare stent 200 is removed, and the bare stent 200 is released.

In the illustrated embodiment, the nesting portion 142 includes a stationary cap 1421 and a transition portion 1422 connected, the transition portion 1422 being located between the guide 141 and the stationary cap 1421. The fixing cap 1421 is made of metal or rigid polymer material, and the limiting groove 143 is disposed at a proximal end of the fixing cap 1421. The transition part 1422 is made of a polymer material with good flexibility, has good bending performance, and can pass through a complex bent blood vessel along with a guide wire. Preferably, the transition part 1422 is made of the same material as the guiding part 141 and is of an integrally molded structure.

Because the outer peripheral surface of the engaging portion 142 is a substantially flat surface, that is, the outer peripheral surfaces of the fixing cap 1421 and the transition portion 1422 are located on the same circumferential surface, and because the materials of the fixing cap 1421 and the transition portion 1422 are different, the fixing cap 1421 and the transition portion 1422 may be fixedly connected by injection molding for the convenience of processing.

Referring to fig. 7, the fixing cap 1421 includes a sleeve 1421a and a connecting member 1421b connected to each other. Wherein, the limiting groove 143 is located at the proximal end of the sleeve 1421a, and the distal end of the inner core tube 110 is fixed at the groove bottom of the limiting groove 143. The connecting member 1421b is a hollow structure, and is connected to the distal end of the sleeve 1421a and is in communication with the sleeve 1421a, and the connecting member 1421b is in communication with the inner core tube 110 to ensure the passage of the guide wire. During processing, the connecting part 1421b is injection molded into the transition part 1422, so that the transition part 1422 is fixedly connected to the fixing cap 1421. Preferably, the diameter of the inner cavity of the connecting part 1421b is larger than the inner diameter of the inner core tube 110, so as to ensure that the connecting part 1421b is connected with the inner core tube 110, and the diameter of the circumscribed circle of the maximum cross section of the connecting part 1421b is smaller than the outer diameter of the sleeve 1421a, so as to ensure that the outer circumferential surface of the sleeve 1421a and the outer circumferential surface of the transition part 1422 in which the connecting part 1421b is accommodated are located on the same circumferential surface.

Referring to fig. 9, in order to increase the connection strength between the fixing cap 1421 and the transition portion 1422 and avoid the separation or detachment of the fixing cap 1421 and the transition portion 1422 during a clinical procedure, an anchoring device 1423 is disposed on the connecting member 1421b for increasing the contact area between the connecting member 1421b and the transition portion 1422. In the illustrated embodiment, the anchoring device 1423 is a circular hole-like open slot. It will be appreciated that the present application is not limited to the specific configuration of the anchoring device 1423, as long as the contact area between the connecting piece 1421b and the transition portion 1422 can be increased, and that the anchoring device 1423 can also be a thread structure, a boss structure, or other open slots disposed on the connecting piece 1421 b.

It is also understood that in other embodiments, the engaging portion 142 may only include the connecting member 1421b, and the guiding portion 141 is directly and smoothly connected to the connecting member 1421 b. During processing, the connecting member 1421b is directly injected into the guide 141, so that the guide 141 and the fixing cap 1421 are fixedly connected.

Referring to fig. 10, the anchor 150 is a hollow structure, the anchor 150 is fixed to the outer core tube 120 as a whole, and an inner cavity of the anchor 150 is communicated with a lumen of the outer core tube 120, so that the anchor 150 and the outer core tube 120 are sleeved outside the inner core tube 110 together and can move axially relative to the inner core tube 110. Referring to fig. 6, the anchor 150 is engaged with the push rod 160 for axially constraining the luminal stent 200, and the anchor 150 is engaged with the limiting groove 143 of the sheathing part 142 for radially constraining the bare stent 220 of the luminal stent.

In the embodiment shown in fig. 10, the anchor 150 includes an insertion portion 151 at the distal end, and an abutting portion 152 at the proximal end and connected to the insertion portion 151, the abutting portion 152 being fixedly connected directly to the outer core tube 120.

The insertion portion 151 is substantially a hollow cylinder, and the outer diameter thereof is slightly smaller than the inner diameter of the limiting groove 143, i.e., the insertion portion 151 can be in clearance fit with the limiting groove 143, so that the insertion portion 143 can be smoothly inserted into the limiting groove 143. The insertion portion 151 cooperates with the stopper groove 143 to radially restrain the bare stent 220 of the lumen stent 200.

The distal end of the abutting portion 152 has a substantially smooth cylindrical profile, and the outer diameter of the distal end of the abutting portion 152 is larger than the inner diameter of the limiting groove 143, so that when the inserting portion 151 is inserted into the limiting groove 143, the distal end surface of the abutting portion 152 abuts against the proximal end surface of the engaging portion 142. Preferably, the outer diameter of the distal end of the abutting portion 152 is substantially equal to the outer diameter of the proximal end of the sleeve portion 142, so as to avoid a step structure between the abutting portion 152 and the sleeve portion 142, and further avoid the unsmooth percutaneous penetration during the clinical operation. The proximal end of the abutting portion 152 has a generally smooth tapered profile, and the proximal end and the distal end of the abutting portion 152 are in smooth transition, so that the abutting portion 152 is prevented from scratching the lumen stent 200 in the process of withdrawing the fixation anchor 150 out of the body, and the safety of the operation is improved. In this embodiment, the insertion portion 151 and the holding portion 152 are integrally formed. It is understood that the insertion portion 151 and the abutting portion 152 can also be fixedly connected by welding, bonding, etc.

Further, the length of the insertion portion 151 along the longitudinal center line of the fixing anchor 150 is not greater than the depth of the limiting groove 142, so as to ensure that the insertion portion 151 and the limiting groove 142 can be completely closed, and avoid a gap along the axial direction between the abutting portion 152 and the nesting portion 142.

Referring to fig. 6 again, the bare stent 220 includes at least one ring of wavy rings, each ring of wavy rings is a closed cylindrical structure including a plurality of peaks 221, a plurality of valleys 222, and a supporting body 223 connecting adjacent peaks 221 and valleys 222. Referring to fig. 10 again, the outer circumferential surface of the anchor 150 is provided with a plurality of positioning grooves 153 arranged at intervals along the circumferential direction, each positioning groove 153 is distributed along the longitudinal center line of the anchor 150 and penetrates through the proximal end surface of the abutting portion 152 and the distal end surface of the insertion portion 151, and the wave crest 221 of the bare bracket 220 and the supporting body 223 are accommodated in the corresponding positioning groove 153.

The first positioning member 154 for hooking the peak 221 is disposed in the positioning groove 153, and the first positioning member 154 is composed of two bosses, namely a first boss 1541 for limiting the forward movement of the bare bracket 220 and a second boss 1542 for limiting the backward movement of the bare bracket 220. Specifically, a clamping groove is formed between the first boss 1541 and the second boss 1542, the diameter of an inscribed circle of the clamping groove is larger than the width of the wave peak 221, and the wave peak 221 is hooked between the two bosses, so that the bare support 220 is axially positioned, and the bare support 220 is prevented from moving under the action of friction force. When the radial constraining force of the bare stent 220 disappears, that is, the insertion part 151 is separated from the limiting groove 143, the bare stent 220 makes the wave crest 221 be separated from the two bosses under the action of the self radial expansion force, thereby completing the release of the bare stent 220. The "width" of a peak herein refers to the length of the peak 221 in the direction of the longitudinal centerline. It can be understood that, when the insertion portion 151 is inserted into the stopper groove 143, a distance between an outer surface of the first positioning member 154 away from the groove bottom of the positioning groove 153 and an inner circumferential surface of the stopper groove 143 is smaller than a thickness of the bare bracket 220 in a radial direction of the anchor 150, and the bare bracket 220 is prevented from falling off between the insertion portion 151 and the stopper groove 143 when moving along with the head 14.

In order to reduce the resistance when the bare stent 220 is released and facilitate the falling of the peak 221 from the second boss 1542, the profile of the second boss 1542 facing the first boss 1541 is a cylindrical surface or a conical surface, that is, the profile of the side of the second boss 1542 contacting the peak 221 is a cylindrical surface or a conical surface.

In the illustrated embodiment, the first boss 1541 has a plate shape and the second boss 1542 has a cylindrical shape. The first boss 1541 and the second boss 1542 are located in the positioning slot 153 of the insertion portion 151, and a line connecting geometric centers of the first boss 1541 and the second boss 1542 is parallel to a longitudinal centerline of the anchor 150. It is understood that in other embodiments, the two bosses may have other structures, such as circular truncated cones; moreover, the proximal end of the second boss 1542 may also extend to the abutting portion, as long as it is ensured that the locking groove between the first boss 1541 and the second boss 1542 is located on the insertion portion 151, that is, it is ensured that the peak 221 of the bare bracket 220 is located on the insertion portion 151, so that the peak 221 of the bare bracket 220 can be inserted into the limiting groove 143 along with the insertion portion 151. It will also be appreciated that the line connecting the geometric centers of first boss 1541 and second boss 1542 may also be disposed obliquely with respect to the longitudinal centerline of anchor 150. That is, the present application does not limit the specific structure and position of the two bosses, as long as the wave crests of the bare metal bracket 220 can be limited within the insertion portion 151, and the bare metal bracket 220 can be limited from moving back and forth.

In the illustrated embodiment, the height of the first positioning member 154 in the radial direction of the anchor 150 is equal to the depth of the positioning groove 153 on the insertion portion 151, i.e., the outer surface of the first positioning member 154 away from the groove bottom of the positioning groove 153 and the outer surface of the insertion portion 151 are located on the same circumferential surface. It will be appreciated that in other embodiments, the height of the first detent 154 in the radial direction of the anchor 150 may also be greater or less than the depth of the detent 153 on the insert 151.

Preferably, the height of the first positioning member 154 in the radial direction of the anchor 150 is not greater than the depth of the positioning groove 153 of the insertion portion 151 so as not to interfere with the engagement between the insertion portion 151 and the stopper groove 143. The ratio of the height of the first positioning member 154 to the thickness of the bare stent 220 in the radial direction of the anchor 150 is 1/2-3/4. If the above ratio is less than 1/2, when the insertion portion 151 is inserted into the limiting groove 143, the distance between the outer surface of the groove bottom of the first positioning member 154 away from the positioning groove 153 and the inner circumferential surface of the limiting groove 143 is easily greater than the thickness of the bare bracket 220 in the radial direction of the anchor 150, and the peak 221 of the bare bracket 220 falls off from the two bosses of the first positioning member 154 when moving along with the tip 14, thereby affecting the axial positioning effect of the first positioning member 154 on the bare bracket 200. If the above ratio is greater than 3/4, when the radial constraining force of the bare bracket 220 disappears, i.e., the insertion portion 151 is separated from the limiting groove 143, the peak 221 of the bare bracket 220 is not easily separated from the two bosses of the first positioning member 154.

Further, a second positioning member 155 is disposed in the positioning groove 153, and the second positioning member 155 is located between the two supporting bodies 223 to separate the adjacent supporting bodies 223 from each other, so as to prevent the adjacent supporting bodies 223 from interfering with each other.

In the illustrated embodiment, the second positioning element 155 is a plate-shaped structure, and is located in the positioning slot 153 of the abutting portion 152, a connection line between the geometric centers of the second positioning element 155 and the second boss 1542 is parallel to the longitudinal center line of the fixing anchor 150, and a surface of the second positioning element 155, which is far away from the bottom of the positioning slot 153, and a surface of the abutting portion 152 are located on the same circumferential surface. It is understood that in other embodiments, the second positioning member 155 may have other structures, such as a column shape, as long as it can separate the adjacent supporting bodies 223 from each other, and the second positioning member 155 may also be located on the insertion portion 151 or across the insertion portion and the abutting portion 152. It can also be understood that the ratio of the height of the second positioning member 155 to the thickness of the bare bracket 220 in the radial direction of the anchor 150 is 1/2-3/4 to facilitate the support body 223 to fall off from the second positioning member 155. If the above ratio is less than 1/2, when the insertion portion 151 is inserted into the stopper groove 143, it is easy to make the distance between the outer surface of the groove bottom of the second positioning member 155 away from the positioning groove 153 and the inner circumferential surface of the stopper groove 143 greater than the thickness of the bare bracket 220 in the radial direction of the anchor 150, which causes the supporting body 223 of the bare bracket 220 to be separated from the second positioning member 155 when moving along with the tip 14, and further causes the adjacent supporting bodies 223 to interfere with each other. If the above ratio is greater than 3/4, when the radial restraining force of the bare bracket 220 disappears, i.e., the insertion portion 151 is separated from the stopper groove 143, the supporting body 223 of the bare bracket 220 is not easily separated from the second positioning member 155.

It is also understood that one detent 153 may contain one peak 221, or may contain multiple peaks 221. When a plurality of wave crests 221 are located in one positioning groove 153, a third positioning member 156 is disposed between two adjacent wave crests 221, and the third positioning member 156 may be in a plate-like or column-like structure, as long as the supporting members 223 connected to two adjacent wave crests 221 can be separated. In the embodiment shown in fig. 8, a plurality of positioning grooves 153 are uniformly distributed along the circumferential direction, one positioning groove 153 accommodates a wave crest 221 and supporting bodies 223 connected to both sides of the wave crest 221, and each positioning groove 153 is provided with a first positioning member 154 and a second positioning member 155.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A conveying system comprises an inner core pipe, a sheath pipe which is sleeved outside the inner core pipe and can move axially relative to the inner core pipe, and an end head which is connected to the inner core pipe and communicated with a pipe cavity of the inner core pipe.

2. The delivery system of claim 1, wherein the difference between the inner diameter of the sheath and the diameter of the circumcircle of the maximum cross-section of the hub is less than or equal to 2 millimeters.

3. The delivery system of claim 1, wherein the outer diameter of the distal end of the nesting portion is no less than the outer diameter of the proximal end, and wherein the included angle between the generatrix of the nesting portion and the longitudinal centerline of the nesting portion is no greater than 8 °.

4. The delivery system of claim 1, wherein the nesting portion comprises a retaining cap comprising a sleeve and a connector attached to a distal end of the sleeve; the connecting piece is of a hollow structure, and the maximum diameter of the circumscribed circle of the cross section of the connecting piece is smaller than the outer diameter of the sleeve.

5. The delivery system of claim 4, wherein the nesting portion further comprises a transition portion connected to the connector.

6. The delivery system of claim 5, wherein the retaining cap is injection molded with the transition portion or the guide portion.

7. A delivery system according to claim 4, wherein an anchoring device is provided on the connector.

8. The delivery system of claim 4, further comprising a fixation anchor attached to a distal end of the outer core tube, and a push tube positioned between the outer core tube and the sheath; the fixing anchor comprises an inserting part and a supporting part which are connected, and the supporting part is fixedly connected with the outer core pipe; when the fixing anchor is folded with the nesting portion, the inserting portion is inserted into the sleeve, and the abutting portion abuts against the nesting portion.

9. The conveying system according to claim 8, wherein the outer circumferential surface of the fixing anchor is provided with at least one positioning groove, the positioning groove penetrates through the proximal end surface of the abutting part, and a first positioning piece for hooking the wave crest of the bare stent is arranged in the positioning groove on the inserting part.

10. The delivery system of claim 9, wherein the first positioning member includes a first boss and a second boss, and the peak is hooked between the first boss and the second boss.