Stent system

Abstract

This invention relates to a support system, including a support and a delivery device. The support includes several connecting rings, and the delivery device includes a sheath and a sheath core movable along the interior of the sheath. A restraining system is disposed outside the sheath core, the restraining system including a restraining section detachably connected to the connecting rings. The restraining section is connected to the connecting rings before the support is completely detached from the sheath on its axis. Compared to conventional delivery systems and supports, this invention can effectively restrict the axial position of the support through the restraining section, thereby reducing and preventing forward sway.

Description

Technical Field

[0001] This invention relates to the field of interventional medical device technology, and more particularly to a stent system. Background Technology

[0002] In recent years, with the improvement of living standards and the aging population in my country, coupled with the low detection and effective control rates of hypertension, the incidence of aortic diseases has been worsening. Common high-risk diseases of the thoracic aorta include aortic aneurysm and aortic dissection. An aortic aneurysm refers to a localized or diffuse abnormal dilation of the aortic wall, compressing surrounding organs and causing symptoms; rupture of the aneurysm is its main risk. Aortic dissection refers to a tear in the intima of the thoracic aorta, destroying the media and allowing blood to enter the vessel wall. Due to the impact of blood flow, once aortic dissection forms, the tear can extend along the direction of blood flow.

[0003] Traditional open surgery for aortic aneurysms and aortic dissections is highly invasive, has a high mortality rate, long operation time, high postoperative complication rate, and is very difficult. Endovascular treatment, on the other hand, is less invasive, has fewer postoperative complications, shorter operation time, and is less difficult, and has gradually become the main method for treating aortic aneurysms and aortic dissections. By implanting a covered stent in the aorta, the vascular lesion is isolated outside the covered stent, restricting blood flow through the stent and thus protecting the blood vessel.

[0004] Most currently available thoracic aortic stent graft products are deployed via a delivery system. The sheath retracts, exposing the stent, which then expands and adheres to the vessel wall, effectively isolating the lesion outside the stent graft. During the procedure, the stent expands and returns to its original shape relatively quickly. As the sheath moves proximally to expose part of the stent, the exposed portion has already begun to expand. This expanded portion pulls the remaining portion distally, causing the stent to jump forward. This forward jump typically leads to the stent deviating from its implantation position. Summary of the Invention

[0005] Therefore, it is necessary to provide an improved stent system to address the potential for forward tripping during stent release, as detailed below:

[0006] A support system is provided, including a support and a delivery device. The support includes a plurality of connecting rings, and the delivery device includes a sheath and a sheath core movable along the interior of the sheath. A restraining system is disposed outside the sheath core, and the restraining system includes a restraining section detachably connected to the connecting rings. The restraining section is connected to the connecting rings before the support is completely detached from the sheath on its axis.

[0007] In one embodiment, the limiting system further includes a connecting segment, which is fixedly connected to or integrally formed with the connecting segment, and the connecting segment is located between the sheath core and the sheath tube.

[0008] In one embodiment, the limiting segment is rod-shaped, and the free end of the limiting segment is angularly deflected relative to the end connected to the connecting segment.

[0009] In one embodiment, the limiting segment passes through the connecting ring from the outside to the inside of the bracket.

[0010] In one embodiment, the limiting segment passes through the connecting ring from the inside to the outside of the bracket.

[0011] In one embodiment, the conveying system includes a limiting ring that receives the free end of a limiting segment from a proximal end to a distal end, such that the free end of the limiting segment is closed after it passes the connecting ring.

[0012] In one embodiment, the receiving member includes a receiving cavity with an opening facing the distal end, the receiving cavity being used to receive the free end of the limiting segment.

[0013] In one embodiment, a ball head is added to the free end of the limiting segment, and the receiving cavity of the receiving component is used to accommodate the ball head.

[0014] In one embodiment, a magnetic baffle is provided at the distal opening of the storage cavity of the storage component, and a magnetic segment is provided at the distal end of the sheath core. When the magnetic segment of the sheath core overlaps with the storage cavity in the axial direction, the magnetic baffle is attracted and extended by the sheath core, preventing the free end of the limiting segment from leaving the storage cavity.

[0015] In one embodiment, the sheath core is provided with a plurality of metal elastic elements with both ends axially disposed on the sheath core. The distance from the outermost point of the metal elastic element to the axis is greater than the inner diameter of the limiting ring. Taking the outermost point of the metal elastic element as the boundary, the axial extension length of the distal side of the metal elastic element is greater than 3 times the axial extension length of the proximal side of the metal elastic element.

[0016] Compared with existing technologies, the present invention provides a support system including a support and a conveying device. The support includes several connecting rings, and the conveying device includes a sheath and a sheath core movable along the interior of the sheath. A limiting system is disposed outside the sheath core, and the limiting system includes a limiting section detachably connected to the connecting rings. The limiting section is connected to the connecting rings before the support is completely detached from the sheath on its axis. Compared with conventional conveying systems and supports, the present invention can effectively limit the axial position of the support through the limiting section, thereby reducing and preventing forward jump. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the stent system in Embodiment 1 of the present invention after release;

[0018] Figure 2 This is a schematic diagram of the structure of the support system in Embodiment 1 of the present invention;

[0019] Figure 3 This is a schematic diagram of the stent system at the end of the release phase in Embodiment 1 of the present invention;

[0020] Figure 4 yes Figure 3 Enlarged view of region A in the middle;

[0021] Figure 5 This is a schematic diagram of the proximal structure of the stent system in Embodiment 1 of the present invention;

[0022] Figure 6 This is a schematic diagram of the proximal structure of the stent system in another embodiment of Embodiment 1 of the present invention;

[0023] Figure 7 This is a schematic diagram of the connection of the limiting section of the support system in Embodiment 1 of the present invention.

[0024] Figure 8 This is a schematic diagram of the structure of the free end of the support system restriction section in another embodiment of Embodiment 1 of the present invention;

[0025] Figure 9 This is a schematic diagram of the support system in the transport state in Embodiment 2 of the present invention;

[0026] Figure 10 This is a schematic diagram of the limiting ring structure of the support system in Embodiment 2 of the present invention;

[0027] Figure 11 This is a partial structural schematic diagram of the support system in another embodiment of Embodiment 2 of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0029] It should be noted that in the field of interventional medical devices, the end of a medical device implanted in the human or animal body that is closer to the operator is generally called the "proximal end," and the end that is farther from the operator is called the "distal end." Based on this principle, the "proximal end" and "distal end" of any component of a medical device are defined. "Axial direction" generally refers to the length direction of the medical device during delivery, and "radial direction" generally refers to the direction of the medical device perpendicular to its "axial direction." Based on this principle, the "axial direction" and "radial direction" of any component of a medical device are defined. The "connection" mentioned in the embodiments includes both direct connection between two components and indirect connection via other components.

[0030] It should be noted that, for implants such as stents, the side closer to the heart is generally referred to as the proximal end, and the side farther from the heart is referred to as the distal end. However, in this invention, to avoid confusion, the end closer to the operator is uniformly referred to as the "proximal end," and the end farther from the operator is referred to as the "distal end," as a reference for describing the direction.

[0031] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0032] Example 1

[0033] Reference Figure 1-2 , Figure 1 This is a schematic diagram of the stent system in Embodiment 1 of the present invention after release. Figure 2 This is a schematic diagram of the structure of the support system in Embodiment 1 of the present invention. The support system in this embodiment provides a support 100 and a corresponding conveying device 200. The conveying device 200 includes a sheath 210 and a sheath core 220 that can slide freely inside the sheath 210. The sheath 210 and the sheath core 220 are used to cooperate in conveying the support 100.

[0034] In the traditional release method, in the initial state, the stent 100 is compressed and placed inside the sheath 210, with the stent 100 and the distal tip 221 of the sheath core 220 connected. After the sheath 210 moves to the predetermined position, that is, in the release state, the position of the sheath core 220 and the stent 100 remain unchanged. Then, the sheath 210 is withdrawn proximally. At this time, the tip 221 located at the distal end of the sheath core 220 tightens the stent 100, restricting the stent 100 from moving with the sheath 210. Thus, the stent 100 is gradually exposed from inside the sheath 210, and the outside of the stent 100 is no longer restricted by the sheath 210. As a result, the stent 100 can expand and return to its original shape. At the same time, the stent 100 is released from the position of the tip 221 of the sheath core 220, thus realizing the implantation process. This implantation process is irreversible. If the position of the sheath 210 is inaccurate, or if the stent 100 is displaced during release, the implantation position of the stent 100 will be deviated, and there is little room for adjustment. Furthermore, it should be noted that the stent 100 expands and returns to its original shape relatively quickly. However, when the sheath 210 gradually moves towards the proximal end and has not yet fully exposed the stent 100, the distal part of the stent 100 has already begun to expand, while the proximal end of the stent 100 is still compressed inside the sheath 210. This causes the stent 100 to tend to move towards the distal end during release. In traditional methods, the stent 100 often moves towards the distal end, i.e., in the direction of release, which is generally referred to as the "forward jump" of the stent 100. The "forward jump" of the stent 100 is an uncontrollable movement, and it is difficult to leave an accurate margin for it to achieve accurate release. The current avoidance method is generally to speed up the release phase of the stent 100, i.e., to release the stent 100 quickly, thereby shortening the release time difference between the distal and proximal ends of the stent 100 and minimizing the risk of the distal end of the stent 100 expanding and causing the proximal end to move towards the distal end when it is not yet expanded.

[0035] Therefore, in this embodiment, a restraint system 230 is added to the sheath core 220. The restraint system 230 includes a connecting section 231 and a restraint section 232. The connecting section 231 extends outside the body along the sheath tube 210 for direct operation by the operator or operation via a handle. The connecting section 231 is located between the inner walls of the sheath core 220 and the sheath tube 210. One end of the restraint section 232 is fixedly connected to the connecting section 231 or integrally formed with the connecting section 231. The other end of the restraint section 232 is detachably connected to the proximal end of the stent 100. Thus, the restraint section 232 can limit the movement of the proximal end of the stent 100 toward the distal end when needed, thereby preventing the stent 100 from "jumping forward" during the release phase.

[0036] Thus, at the start of the release phase, the sheath 210 moves proximally, and the TIP tip 221 at the distal end of the sheath core 220 tightens the stent 100, preventing the stent 100 from moving proximally with the sheath 210. As the sheath 210 gradually moves and continues to expose the distal and middle parts of the stent 100, the distal part of the stent 100 gradually expands and detaches from the TIP tip 221 (at this time, the stent 100 detaches). The distal and middle parts of the stent 100 continue to expand rapidly, showing a tendency to drive the proximal part to move towards the distal part. This tendency is restricted by the limiting segment 232. When the sheath 210 moves to fully expose the stent 100, the proximal part of the stent 100 detaches from the limiting segment 232. At this time, most of the area of ​​the stent 100 has expanded and pressed against the inner wall of the blood vessel, thereby ensuring that the proximal release position of the stent 100 is accurate.

[0037] Reference Figure 3-4 , Figure 3 This is a schematic diagram of the stent system at the end of the release phase in Embodiment 1 of the present invention. Figure 4 yes Figure 3 Enlarged schematic diagram of region A. During the middle stage of release, that is, after the distal and middle parts of stent 100 are released, the imaging point of stent 100 on the distal side expands and approaches or abuts the vessel wall. At this time, the operator can more accurately judge whether its release position is accurate. At this time, the proximal end of stent 100 is still in sheath 210 and is limited by the restricting segment 232. If the release position is inaccurate, sheath 210 can be moved toward the distal end. Under the premise that the restricting segment 232 tightens the proximal end of stent 100, the axial position of stent 100 will not change when sheath 210 moves toward the distal end. At the same time, stent 100 is gradually retracted into sheath 210, thereby detaching from the vessel wall, and then the position can be further adjusted according to the previous positional deviation.

[0038] like Figure 5 The proximal end of the support 100 is provided with a plurality of connecting rings 110, which are used to connect to the limiting section 232. Therefore, in this embodiment, not all supports 100 can be arbitrarily connected to the limiting structure 230. Specifically, the connecting rings 110, as part of the support 100, are generally formed in a ring shape. If there is a film covering structure at the proximal end of the support 100, the connecting rings 110 need to extend beyond the area where the film is located in the axial direction. If there is no film covering structure at the proximal end of the support 100, the connecting rings 110 can be located at the proximal end in the axial direction.

[0039] In another embodiment, reference Figure 6The connecting ring 120 at the proximal end of the stent 100 is not an independent circular ring, but a ring structure formed by twisting the proximal peak of the proximal wave loop of the stent 100 (that is, the closest end of the wave loop). The connecting ring 120 configured in this way is completely part of the stent and can play a role as the margin for proximal expansion of the stent 100 after release.

[0040] In another embodiment, the proximal end of the stent 100 is provided with an even number of connecting rings 110, and for any connecting ring 110, there is a position of the connecting ring 110 that is radially symmetrical with it, so that when the limiting system 230 is connected to the connecting ring 110, the stent 100 can be kept in the middle of the sheath 210, and the proximal end of the stent 100 can be avoided from shifting.

[0041] In another embodiment, the proximal end of the stent 100 is provided with an odd number of connecting rings 110, wherein the multiple connecting rings 110 are symmetrical along the axis, so that when the restraint system 230 is connected to the connecting rings 110, the stent 100 can be kept in the middle of the sheath 210, and the proximal end of the stent 100 can be avoided from shifting.

[0042] In this embodiment, refer to Figure 7 , Figure 7 This is a schematic diagram of the connection of the limiting segment 232 of the support system in Embodiment 1 of the present invention. The limiting segment 232 is rod-shaped, and the free end of the limiting segment 232 is deflected at an angle relative to the end connected to the connecting segment 231, that is, the limiting segment 232 is bent. In this embodiment, the limiting segment 232 passes through the connecting ring 110 from the outside to the inside of the support 100. When the proximal end of the support 100 is compressed, the proximal end of the support 100 adheres tightly to the inner wall of the sheath tube 210, thereby causing the connecting ring 110 to also adhere tightly to the inner wall of the sheath tube 210, which in turn causes the limiting segment 232 to be pressed tightly against the inner wall of the sheath tube 210. Based on this, if forward jump is to be prevented, only a small force needs to be provided by the limiting segment 232.

[0043] Similarly, in another embodiment, the limiting segment 232 passes through the connecting ring 110 from the inside to the outside of the support 100, so that the free end of the limiting segment 232 is pressed between the outside of the support 100 and the inside of the sheath 210. On this basis, it is equivalent to the free end of the limiting segment 232 being locked to the inner wall of the sheath 210 by the expansion force of the support 100. When the support 100 is not fully exposed, the limiting segment 232 can always firmly limit the axial position of the proximal end of the support 100.

[0044] In another embodiment, reference Figure 8 , Figure 8 This is a schematic diagram of the free end structure of the limiting segment in another embodiment of Embodiment 1 of the present invention. The free end of the limiting segment is preferably in the shape of a clamp. The free end of the limiting segment 233 can be connected to and released from the support by opening and closing the clamp.

[0045] In this embodiment, it should be noted that the expansion force of the stent 100 is very strong. The restricting segment 232 is generally made of elastic metal materials such as nickel-iron alloy, which cannot prevent the radial expansion of the stent 100 on its own. That is to say, when the sheath 210 retracts to just expose the restricting segment 232, the proximal end of the stent 100 will rapidly expand and detach from the restricting segment 232. In another embodiment, the restricting segment 232 extends for a relatively long length after passing the stent 100, so that when the sheath 210 retracts to just expose the restricting segment 232, the restricting segment 232 can open at a certain angle, thereby limiting the speed of expansion of the proximal end of the stent 100. This can reduce the impact of the proximal end of the stent 100 on the vessel wall when it is fully opened later. Preferably, the length of the restricting segment 232 after passing the stent 100 is greater than 1 / 4 of the inner diameter of the stent 100 in its natural state.

[0046] It should be noted that, since the limiting system 230 in this embodiment only limits the proximal end of the stent 100, if the limiting section 232 is made of wire, it will be difficult to pull because it is close to the inside of the sheath 210 during the release phase. Since the limiting section 232 is for preventing premature sag and is the last part to be released, it will be released after the last part of the sheath is removed. Similarly, since the expansion force of the stent 100 is very large, it is difficult to restrain it with just the wire. If the proximal end of the stent 100 expands and presses against the blood vessel wall, the limiting section 232 will be pressed between the stent 100 and the blood vessel wall. Since the limiting section 232 is made of wire, pulling the limiting section 232 will inevitably cause damage to the blood vessel wall. Therefore, in the corresponding case of this embodiment, a pull wire cannot be used. It should be specifically noted that in some solutions, the reason why a wire can be used to fix the proximal end of the stent 100 at the TIP head position is that when the distal end of the stent 100 just leaves the sheath 210, most of the area of ​​the stent 100 is still inside the sheath 210. Therefore, the expansion force at the distal end of the stent 100 is not large. At this time, the wire does not need to bear excessive tension, and it is not directly pressed against the blood vessel wall, so the operation can be performed.

[0047] It should be noted that this invention does not involve improvements to the connection method between the TIP head 221 and the far end of the bracket 100. The TIP head 221 can be designed with a hook or a pull wire, which are commonly used, to work with the limiting system 20 to prevent "forward jump".

[0048] Example 2

[0049] This embodiment further improves the restriction system; see details below. Figure 9-10 ,in, Figure 9 This is a schematic diagram of the support system of Embodiment 2 of the present invention in the transport state. Figure 10 This is a schematic diagram of the limiting ring structure of the support system in Embodiment 2 of the present invention.

[0050] When the proximal connecting ring 110 of the stent 100 is limited, that is, after the limiting segment 232 is attached to the proximal end of the stent 100, the effect is mainly due to the expansion properties of the proximal end of the stent 100 and the non-expandable characteristic of the sheath 210. In most working conditions, the limiting segment 232 will not detach from the position of the sheath 210. However, in this embodiment, a limiting ring 240 is added. The limiting ring 240 receives the free end of the limiting segment 232 from the proximal end to the distal end, so that the free end of the limiting segment 232 is closed after passing the proximal connecting ring 110 of the stent 100. Thus, when the limiting segment 232 does not detach from the limiting ring 240, the limiting segment 232 can always limit the proximal end of the stent 100.

[0051] For the limiting ring 240, the limiting ring 240 includes a receiving member 241, a connecting member 242 and a support ring 243. The support ring 243 is sleeved on the outside of the sheath core 220 and can move freely relative to the sheath core 220. One end of the connecting member 242 is connected to the support ring 243, and the other end is on the surface of the receiving member 241. The receiving member 241 includes a receiving cavity 2411 with an opening facing the distal end. The receiving cavity 2411 is used to accommodate the free end of the limiting segment 232.

[0052] The limiting ring 240 extends to the operator's operable position via an elastic or rigid support rod, and the limiting ring 240 and the limiting segment 232 move relatively independently. Thus, the operator can control the limiting ring 240 to remain in place or move further distally, while keeping the limiting segment 232 in place or pulling it proximally. This allows both to maintain good or further enhance the limiting effect. Thus, through the cooperation of the limiting ring, the limiting segment 232 in this embodiment can be exposed from the sheath 210, thereby better limiting the proximal position of the stent 100. When it is necessary to release the proximal end of the stent 100, simply remove the limiting ring 240 or push the limiting segment 232 to separate the limiting ring 240 and the limiting segment 232, thereby allowing the proximal end of the stent 100 to expand.

[0053] Therefore, to better restrict the free end of the restricting segment 232, a ball head can be added to the free end of the restricting segment 232. The receiving cavity 2411 of the receiving member 241 is used to accommodate the ball head structure. Furthermore, in another embodiment, a magnetic baffle is provided at the distal opening of the receiving cavity 2411 of the receiving member 241. At the same time, a magnetic attracting segment and an adjacent repulsion segment are provided on the distal side of the sheath core 220. When the magnetic attracting segment of the sheath core 220 overlaps with the receiving cavity 211 in the axial direction, the magnetic baffle is attracted and extended by the sheath core 220, preventing the free end of the restricting segment 232 from leaving the receiving cavity 2411. When the sheath core 220... When the repulsion section of the sheath 220 overlaps with the receiving cavity 211 in the axial direction, the magnetic baffle is repelled by the sheath core 220 and retracts. However, when the support 100 is entirely inside the sheath tube 210, the magnetic section closes the distal opening of the receiving cavity 2411. When the sheath tube 210 is pulled and the distal end of the support 100 is released, the sheath core 220 can move freely. Thus, the movement of the sheath core 220 can control the opening and closing of the receiving cavity 2411. Since the sheath core 220 needs to be retracted into the sheath tube 210 later, a repulsion section can be set on the farthest side of the sheath core 220 so that the sheath core 220 opens the opening of the receiving cavity 2411 when it is retracted.

[0054] In another embodiment, reference Figure 11 , Figure 11 This is a partial structural diagram of the support system in another embodiment of Embodiment 2 of the present invention. Further, a plurality of metal elastic elements 250 are provided on the sheath core 220 along the axial direction. The two ends of the metal elastic elements 250 are arranged on the sheath core 220 along the axial direction. In particular, the distal end of the metal elastic element 250 gradually and slowly rises from the surface of the sheath core 220, and then rapidly descends after reaching the maximum rising position. The distance from the outermost point of the metal elastic element 250 to the axis is greater than the inner diameter of the support ring 243. Taking the outermost point of the metal elastic element 250 as the boundary, the axial extension length of the distal end 251 of the metal elastic element 250 is more than 3 times the axial extension length of the proximal end 252. This allows the metal elastic element 250 to pass smoothly toward the distal end through the support ring 243. Conversely, when the metal elastic element 250 moves from the distal end to the proximal end, it is difficult to pass through the support ring 243. Therefore, when the sheath core 220 drives the metal elastic element 250 to move towards the proximal end, the metal elastic element 250 will resist the support ring 243, thereby pushing the support ring 243 to move towards the proximal end.

[0055] Since the sheath core 220 in this embodiment is provided with multiple metal elastic elements 250 along the axial direction, in the initial state, the limiting ring 240 is located between two adjacent metal elastic elements 250 in the axial direction. Therefore, when the sheath core 220 is pushed to the distal end, the limiting ring 240 can be pressed and reinforced, causing it to move or be pressed towards the distal end. Thus, the limiting ring 240 can be pressed and reinforced at almost any time, making it better for limiting the limiting segment 232. When the sheath core 220 is pulled to the proximal end, the limiting ring 240 can be pushed to the proximal side, thereby unlocking the limiting segment 232.

[0056] Furthermore, the outermost position of the metal elastic member 250 is located on its own proximal end side, making it easier for the metal elastic member 250 to pass through the support ring 243 from the proximal end to the distal end, and more difficult for it to pass through the support ring 243 from the distal end to the proximal end.

[0057] It should be noted that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] It should also be noted that the above embodiments do not exclude the technical solution of adding anchor spikes. In order to meet specific situations, the above embodiments can be equipped with anchor spikes as needed.

[0059] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A support system, comprising a support and a conveying device, characterized in that: The support includes several connecting rings, and the conveying device includes a sheath, a sheath core movable relative to the sheath along the axial direction of the sheath, and a limiting system disposed outside the sheath core. The limiting system includes a limiting section detachably connected to the connecting rings. The limiting section is connected to the connecting rings before the support is completely detached from the sheath along the axis.

2. The support system according to claim 1, characterized in that, The limiting system further includes a connecting section, which is fixedly connected to the distal end of the connecting section or integrally formed with the connecting section, and the connecting section is located between the sheath core and the sheath tube.

3. The support system according to claim 2, characterized in that, The limiting segment is rod-shaped, and the free end of the limiting segment is angularly deflected relative to the end connected to the connecting segment.

4. The support system according to claim 3, characterized in that, In the transport state, the limiting section passes through the connecting ring from the outside to the inside of the bracket.

5. The support system according to claim 3, characterized in that, In the transport state, the limiting section passes through the connecting ring from the inside to the outside of the bracket.

6. The support system according to claim 1, characterized in that, The conveying system includes a limiting ring that can accommodate the free end of the limiting segment, so that after the limiting segment passes the connecting ring, the free end of the limiting segment can be limited by the limiting ring.

7. The support system according to claim 6, characterized in that, The receiving component includes a receiving cavity with an opening facing the distal end, the receiving cavity being used to accommodate the free end of the restricting segment.

8. The support system according to claim 7, characterized in that, The free end of the restricted section is further provided with a ball head, and the storage cavity of the storage component is used to accommodate the ball head.

9. The support system according to claim 8, characterized in that, The storage component has a magnetic baffle at the far end of the storage cavity and a magnetic segment at the far end of the sheath core. When the magnetic segment of the sheath core overlaps with the storage cavity in the axial direction, the magnetic baffle is attracted by the sheath core and extends out, preventing the free end of the limiting segment from leaving the storage cavity.

10. The support system according to claim 7, characterized in that, The sheath core is provided with a plurality of metal elastic elements with both ends arranged axially on the sheath core. The distance from the outermost point of the metal elastic element to the axis is greater than the inner diameter of the limiting ring. Taking the outermost point of the metal elastic element as the boundary, the axial extension length of the distal side of the metal elastic element is greater than 3 times the axial extension length of the proximal side of the metal elastic element.

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