Loader for assisting sheath entry of stent and manufacturing method thereof

Abstract

The invention relates to a loader for assisting stent sheathing and a manufacturing method thereof, the loader is used for sleeving a sheathing canal, and the loader comprises a first protection section, a second protection section, a third protection section, a fourth protection section, a fifth protection section and a sixth protection section, a pipe cavity of the second protection section is conical, and the large end side of the second protection section is connected with the first protection section; the tube cavity of the loading leading-in section is conical, and the small end side of the loading leading-in section is connected with the small end side of the second protection section through a second step section; the inner diameter D4 of the protection section is larger than the maximum outer diameter D1 of the sheathing canal, and the minimum diameter D5 of the second step section is smaller than the minimum inner diameter D2 of the sheathing canal. The loader can assist the intravascular stent in entering the inner cavity of the sheathing canal, the difficulty of the stent entering the sheathing canal is reduced, the doctor labor is reduced, and the operation success rate is improved.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to a loader for assisting stent sheathing and a manufacturing method thereof. Background Art

[0002] At present, aortic aneurysm and aortic dissection are common vascular diseases. Aortic aneurysm refers to the local or diffuse abnormal expansion of the aortic wall. Aortic aneurysm will compress the surrounding organs and cause symptoms. Aneurysm rupture is the main danger. Arterial dissection refers to the partial damage of the aortic intima, and high-pressure blood flow rushes into the blood vessel wall, causing the complete aortic wall structure to be split into two, and a dissection cavity is formed in the gap between the inner and outer wall parts of the dissection.

[0003] Since the 21st century, intraluminal aortic stent grafting has been gradually and widely used in the treatment of lesions such as aneurysms and dissections of the thoracic and abdominal aorta. It has a precise effect, less trauma, faster recovery and fewer complications, and has become the first-line treatment method.

[0004] Usually, the stent needs to be delivered to the predetermined lesion location through a delivery system and then released. The delivery system generally includes a sheath and a handle. The sheath enters the lesion location through the artery and releases the stent. Since the size of the stent is larger than the inner diameter of the sheath, the stent needs to be compressed before it can enter the lumen of the sheath, so there are certain difficulties in how to load the stent into the sheath. Summary of the invention

[0005] Based on this, it is necessary to provide a loader for assisting stent insertion into the sheath tube to address the problem of certain difficulties in loading the stent into the sheath tube, so as to assist the vascular stent into the inner cavity of the sheath tube, reduce the difficulty of loading the stent into the sheath tube, reduce the labor of doctors, and improve the success rate of the operation. The present invention relates to a loader for assisting the stent into the sheath tube, the loader can be detachably loaded on the sheath tube, including: a first protective segment, whose lumen is cylindrical and has an inner diameter D4 of the protective segment; a second protective segment, whose lumen is conical and the large end side is connected to the first protective segment; a loading introduction segment, whose lumen is conical, and the small end side is connected to the small end side of the second protective segment through a second stage; the inner diameter D4 of the protective segment is greater than the maximum outer diameter D1 of the sheath tube, and the minimum diameter D5 of the second stage is smaller than the minimum inner diameter D2 of the sheath tube.

[0006] Furthermore, a transition section is provided between the second stage and the loading introduction section. The inner cavity of the transition section is cylindrical and its inner diameter is equal to the minimum diameter D5 of the second stage.

[0007] Furthermore, a transition section is provided between the second stage and the loading introduction section. The inner cavity of the transition section is conical, and its minimum inner diameter is equal to the minimum diameter D5 of the second stage, and its maximum inner diameter is smaller than the maximum diameter D6 of the loading introduction section.

[0008] Furthermore, the inner cavity of the second stage is conical.

[0009] Furthermore, the second stage is formed with a cross section along its axial direction, and the inner wall of the second stage is a curved segment in the cross section.

[0010] Furthermore, an anti-slip protrusion is arranged on the inner wall of the second protection section.

[0011] Furthermore, the loader further comprises an introduction section, wherein the introduction section is connected to the first protection section via a first stage, and a minimum inner diameter of the introduction section is greater than an inner diameter of the first protection section.

[0012] Furthermore, the inner diameter D4 of the protection section and the maximum outer diameter D1 of the sheath tube satisfy 1.02D1≤D4≤1.12D1.

[0013] Furthermore, the minimum diameter D5 of the second stage and the minimum inner diameter D2 of the sheath tube satisfy 0.96D2≤D5≤0.98D2.

[0014] The present invention also relates to a method for manufacturing a loader for the auxiliary stent sheathing as claimed in the claim, the method comprising: sleeve a heat shrink tube on the outer periphery of a heat shrink rod assembly, the heat shrink rod assembly constituting a forming mold of the loader; heating the heat shrink tube so that the heat shrink tube shrinks and fits into the heat shrink rod assembly.

[0015] The technical solution of the present invention has the following beneficial effects:

[0016] 1. The loader of the present invention has a simple structure, low cost, and is easy to use. After the sheath tube is sheathed, it can be removed from the sheath tube or directly torn open and removed.

[0017] 2. The loader of the present invention can greatly reduce the difficulty of sheathing the stent and protect the sheath opening. It can protect the sheath opening while assisting the stent to enter the sheath lumen, thereby reducing the difficulty of sheathing and avoiding damage to the stent or sheath due to improper operation during the sheathing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the assembly structure of the loader and the sheath tube in the first embodiment;

[0019] Figure 2 is a schematic structural diagram of a loader in the first embodiment;

[0020] Figure 3 is a schematic diagram of the assembly structure of the loader and the sheath tube in the second embodiment;

[0021] Figure 4is a schematic structural diagram of a loader in a second embodiment;

[0022] Figure 5 This is a schematic diagram of the structure of the stent before it is sheathed;

[0023] Figure 6 It is a schematic diagram of the structure of the stent being inserted into the sheath;

[0024] Figure 7 This is a schematic diagram of the structure of the stent after it has been sheathed;

[0025] Figure 8 is a schematic diagram of the assembly structure of the loader and the sheath tube in the third embodiment;

[0026] Fig. 9 is a schematic structural diagram of a loader in a third embodiment;

[0027] Fig.10 is a schematic diagram of the assembly structure of the loader and the sheath tube in the fourth embodiment;

[0028] Fig.11 is a schematic structural diagram of a loader in a fourth embodiment;

[0029] Fig.12 is a schematic diagram of the assembly structure of the loader and the sheath tube in the fifth embodiment;

[0030] Fig.13 is a schematic structural diagram of a loader in a fifth embodiment;

[0031] Fig.14 is a schematic diagram of the overall structure of the loader manufacturing process in the sixth embodiment;

[0032] Fig.15 is a schematic structural diagram of a first heat shrink rod in a sixth embodiment;

[0033] Fig.16 is a schematic structural diagram of a second heat shrink rod in the sixth embodiment;

[0034] Fig.17 It is a schematic diagram of the structure of the heat shrink tube after cooling and forming in the sixth embodiment. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific implementation disclosed below.

[0036] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. When an element is connected or disposed inside another element, the entire element may be disposed inside the other element, or a portion of the element may be disposed inside the other element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0038] It should be noted that, for vascular stents, the end closer to the heart after implantation in the blood vessel is generally referred to as the "proximal end" of the stent, and the end farther from the heart after implantation in the blood vessel is referred to as the "distal end" of the stent. The "proximal end" and "distal end" of any component of the stent are defined based on this principle. For a conveyor, the end of the conveyor that is relatively close to the operator is generally referred to as the "proximal end", and the end of the conveyor that is relatively far from the operator is referred to as the "distal end". The "proximal end" and "distal end" of any component of the conveying system are defined based on this principle. "Axial" generally refers to the length direction of the stent when it is being transported, and "radial" generally refers to the direction of the stent that is perpendicular to its "axial direction". The "axial" and "radial" of any component of the stent graft are defined based on this principle.

[0039] First embodiment

[0040] See also Figure 1As shown, this embodiment provides a loader 10 for assisting stent sheathing, which is used to cooperate with the sheath tube 100 to realize the sheathing operation of the stent 500. When the stent 500 needs to be loaded into the sheath tube 100, the loader 10 is first sleeved on the distal peripheral part of the sheath tube 100 to realize the assembly of the loader 10 and the sheath tube 100. The loader 10 assists the stent 500 to enter the inner cavity of the sheath tube 100 to reduce the difficulty of stent sheathing. The stent 500 in this embodiment is a vascular stent, such as a coated stent, a bare stent, an aortic stent, a venous stent, etc., and the specific form, application occasions, etc. of the stent are not specifically limited. The sheath tube 100 includes a main body 101 and a distal end portion 102 connected to the main body, and the end of the distal end portion 102 constitutes a sheath tube port. In order to facilitate the sheath tube to enter the blood vessel and reduce the damage of the sheath tube port to the blood vessel wall, the distal end portion 102 is usually set as a tapered tube structure with a diameter gradually decreasing toward the distal end. The outer diameter of the main body 101 is D1, the minimum inner diameter of the distal end 102 is D2, and the cone angle is β.

[0041] See also Figure 2 As shown, the specific structure of the loader 10 in this embodiment is described. The loader 10 has a central axis and is a hollow tubular structure as a whole. Along the direction of the central axis, the loader 10 includes a plurality of connecting sections, and each connecting section is connected in sequence to form the loader 10 in this embodiment. Specifically, the loader 10 includes an introduction section 11, a first stage 15, a first protection section 12, a second protection section 13, a second stage 14, and a loading guide section 16, which are connected in sequence from the proximal end (the left end shown in the figure) to the distal end (the right end shown in the figure), and each connecting section will be described in detail below.

[0042] See also Figure 2 As shown, the introduction section 11 guides the sheath tube 100 into the lumen of the loader 10 during the assembly process of the loader 10 and the sheath tube 100. The inner cavity of the introduction section 11 may be cylindrical, that is, its inner wall is a straight section, extending in a direction parallel to the central axis, and the inner diameter of the introduction section is a constant value. In other embodiments, the inner cavity of the introduction section 11 may also be conical, that is, the inner wall is in a cone shape. In order to facilitate the sheath tube 100 to be loaded into the inner cavity of the loader 10, when its inner wall is in a cone shape, it is preferred that the inner diameter of the introduction section gradually decreases from the proximal end to the distal end. When the inner wall of the introduction section 11 is in a cone shape, the distal end of the introduction section 11 has a minimum inner diameter. In this embodiment, the fixed inner diameter and the minimum inner diameter of the introduction section 11 are collectively referred to as the introduction section inner diameter D3. In order to facilitate the loader 10 to be installed on the outer end of the sheath 100 through the introduction section 11, and also to facilitate the disassembly and assembly of the loader 10 after the bracket 500 enters the sheath 100, the inner diameter D3 of the introduction section 11 should be larger than the outer diameter D1 of the main body of the sheath 100. Specifically, the inner diameter D3 of the introduction section 11 and the outer diameter D1 of the main body should satisfy: D3-D1≥6mm.

[0043] Continue to see Figure 1-2 As shown, the distal end of the introduction section 11 is connected to the proximal end of the first protection section 12 through the first stage 15. The lumen of the first protection section 12 is cylindrical, that is, its inner wall extends in a direction parallel to the central axis, and has a protection section inner diameter D4. Since the inner diameter D3 of the introduction section 11 is larger than the inner diameter D4 of the protection section, a first stage 15 is formed at the connection between the two, and the connection between the introduction section 11 and the first protection section 12 with a size difference is achieved through the first stage 15. During the actual use of the sheath tube 100, the distal end 102 and the adjacent section adjacent to the distal end are both vulnerable parts. In this embodiment, the adjacent section refers to a local section with a certain length (10mm-40mm) connected to the distal end 102 on the main body 101. In order to realize the protection of the adjacent section by the first protection section 12, and to facilitate the installation of the loader 10 on the periphery of the sheath tube 100, the inner diameter D4 of the protection section should be larger than the outer diameter D1 of the main body of the sheath tube 100. When the stent 500 enters the sheath tube 100, it will be compressed, and its elastic restoring force will cause the sheath tube 100 to expand, and at this time the sheath tube 100 is at risk of being damaged. The first protective section 12 sleeved on the outside of the sheath tube 100 will support the outer wall of the adjacent section of the sheath tube 100, limit the expansion degree of the sheath tube 100 to a certain extent, and then realize the protection of the sheath tube 100. In addition, due to the limiting effect of the first protective section 12, the sheath tube 10 will be deformed more uniformly in the axial and circumferential directions, preventing the sheath tube 10 from being damaged due to excessive local deformation. For D4, a suitable value should be taken. If D4 is too large, the limiting effect on the sheath tube 100 will be reduced, which will lead to a weakening of its protective effect. If D4 is too small, the expansion degree of the sheath tube 100 will be excessively limited, and the elastic restoring force of the stent will be increased, resulting in the stent causing damage to the inner wall of the sheath tube during the sheathing process. Therefore, the ratio of the inner diameter D4 of the protective section to the outer diameter D1 of the main body of the sheath tube 100 satisfies 1.02≤D4 / D1≤1.12.

[0044] Continue to see Figure 1-2As shown, the first protection segment 12 is connected to the second protection segment 13. The inner wall shape of the first protection segment 13 matches the outer wall shape of the distal end portion 102 of the sheath 100, so that the second protection segment 13 can be sleeved on the outer periphery of the distal end portion 102 to protect the distal end portion 102. Specifically, the lumen of the second protection segment 13 is conical and its large end side is connected to the first protection segment 13. In other words, the inner wall surface of the second protection segment 13 in the cross section along the axial direction is conical. The cone angle of the second protection segment 13 is substantially equal to the cone angle β of the distal end portion 102, and its length matches the length of the distal end portion 102. Optionally, the length of the distal end portion 102 is slightly greater than the length of the first protection segment 13, that is, the difference in length between the two can be in the range of 0.5-10 mm. When the stent enters the sheath 100, the elastic restoring force of the stent will cause the conical distal end portion 102 to be expanded, which may cause the distal end portion 102 to split and cause the sheath tube port to be damaged. At this time, the second protective segment 12 sleeved on the outside of the sheath 100 will support the outer wall of the distal end 102, limit its expansion to a certain extent, and make the deformation of the distal end in the axial and circumferential directions more uniform, thereby protecting the distal end 102 and preventing the stent from causing the sheath opening to crack during the sheath insertion process. In this embodiment, the second protective segment 13 and the distal segment 102 are in an interference fit manner, and the tapered section of the second protective segment 13 cooperates with the outer wall of the distal segment 102 to achieve the anchoring of the sheath 100 and the loader 10, ensuring that the distal segment 102 of the sheath 100 will not separate from the second protective segment 13 during the stent insertion process. Optionally, the hardness of the first protective segment 12 and the second protective segment 13 is greater than the hardness of the adjacent segment of the sheath 100 and the hardness of the distal end 102, respectively, to better achieve the protective function.

[0045] Continue to see Figure 1-2As shown, the second protection section 13 is connected to the loading guide section 16 through the second stage 14. The lumen of the loading guide section 16 is conical or trumpet-shaped, and its inner diameter gradually increases from the proximal end to the distal end. The loading guide section 16 adopts a conical tubular structure, and its inner diameter gradually increases, so as to facilitate the stent 500 to smoothly enter the inner cavity of the loader 10 along the loading guide section 16. The cone angle θ of the loading guide section 16 is greater than 0 degrees and less than 90 degrees. Optionally, the cone angle θ should satisfy 30°≤θ≤60°. The minimum diameter of the loading guide section 16 is D5, and the maximum diameter is D6. In order to facilitate the stent to enter the loading guide section 16, the maximum diameter D6 is optionally greater than the outer diameter of the stent in the natural state; when the stent enters the loading guide section 16, as it continues to advance, the outer diameter of the stent will gradually decrease, and when it slides to the proximal end of the loading guide section 16, the size of the proximal end of the stent (the end that has entered the loading guide section is the proximal end) reaches the minimum, and at this time, the proximal size is less than or equal to D5. In order to facilitate the stent to enter the sheath 100, the minimum diameter D5 of the loading guide section 16 is made smaller than the minimum inner diameter D2 of the distal end 102. In this way, when the stent reaches the proximal end of the loading guide section 16 and continues to move, the proximal outer diameter of the stent has been compressed to be smaller than the minimum inner diameter D2, so that the stent can smoothly enter the distal end 102 of the sheath 100 and then enter the inside of the sheath, thereby realizing the auxiliary role of the loader 10 in the stent entering the sheath. In this embodiment, the second stage 14 is used to realize the connection between the second protection section 13 and the loading guide section 16. The minimum inner diameter D5 of the second protection section 13 can be further reduced by the second stage 14 to ensure that its D5 is smaller than the minimum inner diameter D2 of the distal end 102, so that the proximal end of the stent is compressed to a suitable size to facilitate entering the sheath 100. Optionally, the minimum diameter D5 of the loading guide section 16 satisfies 0.96D2≤D5≤0.98D2, that is, the ratio of D5 to D2 is [0.96,0.98]. On the one hand, the endpoint values ​​of the interval are all less than 1, which ensures that D5 is less than D2; on the other hand, the endpoint values ​​are all close to 1, so that the value of D5 is close to D2 to prevent the stent from being over-compressed and damaged.

[0046] The inner cavity of the second stage 14 is conical, that is, its inner wall is a straight line segment in the cross section of the tube wall along the axis. Since it is connected to the loading guide section 16, its minimum inner diameter is equal to the minimum inner diameter of the loading guide section 16, which is also D5.

[0047] The outer wall of the loader in this embodiment can remain parallel to the inner wall of the loader, so that the wall thickness of each connecting section of the loader remains unchanged. In other embodiments, only part of the outer wall can remain parallel to the inner wall, or all the outer walls are not parallel to the inner wall, so that the wall thickness of at least part of the connecting section changes; in addition, in the cross section of the loader along the axial direction, the outer wall of the loader can be a straight line segment, a curved segment or other shapes. In this embodiment, as long as the cavity formed by the inner wall of each connecting section of the loader is ensured to be a cylinder or a cone, so as to cooperate with the sheath, protect the sheath, and assist the stent in sheathing, there is no special requirement for the shape of the outer wall of the loader.

[0048] In other embodiments, the loader may only include a first protective segment, a second protective segment, a second stage, and a loading guide segment connected in sequence, but not include an introduction segment and a first stage. In this case, the sheath directly enters the loader lumen through the first protective segment without passing through the introduction segment.

[0049] Second embodiment

[0050] The structure of the loader in this embodiment is basically the same as that of the loader in the first embodiment, and the only difference is that other structures are provided between the second stage and the loading guide section.

[0051] Specifically, the loader 20 in this embodiment also includes, along the axial direction, a sequentially connected introduction section 21, a first stage 25, a first protection section 22, a second protection section 23, a second stage 24, and a loading guide section 27. Compared with the first embodiment, this embodiment further adds a transition section 26 between the second stage 24 and the loading guide section 27, and the other structures are basically the same as those of the first embodiment.

[0052] See also Figure 3-4 As shown, the transition section 26 is a tube section parallel to the central axis of the loader 20, and the inner cavity is cylindrical, one end of which is connected to the second stage 24, and the other end is connected to the loading guide section 27. The inner wall surface of the transition section 26 is parallel to the central axis, and has a constant inner diameter, which is equal to the minimum inner diameter of the second stage 24, both of which are D5. In this embodiment, the inner diameter of the transition section 26 is also equal to the minimum inner diameter of the loading guide section 27. In order to achieve the auxiliary effect of the loader 20 on the sheathing of the stent, optionally, the inner diameter D5 of the transition section satisfies 0.96D2≤D5≤0.98D2.

[0053] In this embodiment, a transition section 26 with a certain length is provided between the second stage 24 and the loading guide section 27, and the inner diameter of the transition section 26 is equal to the minimum inner diameter of the loading guide section 24 and the minimum inner diameter of the second stage 24. In this way, when the proximal end of the stent 500 enters the loading guide section 27, the stent will be gradually compressed, and its compressed size is less than or equal to D5. As the stent continues to advance, it will enter the transition section 26. Since the inner diameter of the transition section 26 is also D5, the stent size with a certain length (less than or equal to the length of the transition section 26) on the proximal side of the stent will also be compressed to be less than the minimum inner diameter D2 of the distal end of the sheath tube 100. As the stent continues to advance, the stent will gradually enter the sheath tube 100 and expand to abut against the inner wall of the sheath tube. In this embodiment, by providing the transition section 26, when the stent enters the distal end of the sheath tube from the loading guide section 27, the local section of the stent with a certain length is first compressed to the compressed size, and then enters the sheath tube, so that the compression deformation of the stent is smoother.

[0054] The following is a description of the process of assisting the stent 500 to enter the inner cavity of the sheath tube 100 through the loader 20. Figure 5 As shown, the stent 500 is passed through the sheath core assembly 600 to prepare for the subsequent stent sheathing. Figure 6 As shown, the proximal end (sheath end) of the stent is radially compressed to reduce its size. For stents with smaller radial forces, radial contraction can be achieved by pinching with hands or the like, and for stents with larger radial forces, radial contraction can be achieved by tying wires. The stent 500 with the contracted proximal end is extended into the loader 20 and the stent 500 is continued to be pushed so that it enters the protective cover. Then the sheath core assembly 600 and the stent 500 are kept stationary, and the sheath tube 100 is pushed toward the distal end (close to the TIP head), so that the stent 500 gradually enters the inner cavity of the sheath tube through the loader 20. During the pushing process, the stent 500 can be radially contracted synchronously to reduce the difficulty of sheathing the stent 500. When the stent is completely entered into the sheath tube and the loader 20 is removed from the sheath tube 100, the TIP head is partially accommodated in the sheath tube to reduce the possibility of obvious faults between the TIP head and the outer sheath tube when the conveyor passes through a curved blood vessel, thereby reducing the chance of damaging the blood vessel, such as Figure 7 shown.

[0055] Third embodiment

[0056] The structure of the loader in this embodiment is basically the same as that of the loader in the second embodiment, and the only difference is the structure of the transition section.

[0057] See also Figure 8-9As shown, similar to the second embodiment, the loader in this embodiment also includes an introduction section 31, a first stage 35, a first protection section 32, a second protection section 33, a second stage 34, a transition section 36 and a loading guide section 37 connected in sequence. Unlike the second embodiment in which the transition section end is a pipe section parallel to the central axis of the loader, the transition section 36 in this embodiment is a tapered tube, and its inner cavity is conical. Specifically, the proximal end of the transition section 36 is connected to the second stage 34 and has a minimum inner diameter D5, and the distal end is connected to the loading guide section 37 and has a maximum inner diameter D7. Among them, D7 is the maximum inner diameter of the transition section 36 on the one hand, and the minimum diameter of the loading guide section 37 on the other hand. Among them, based on the same reasons as above, D5 should be smaller than the minimum inner diameter D2 of the distal end 102. Optionally, D5 should satisfy 0.96D2≤D5≤0.98D2.

[0058] In this embodiment, the outer diameter of the stent in the natural state is D0. The transition section 36 is set to a tapered tubular shape, so that when entering the loader, the size of the stent is first gradually compressed from D0 to D7, and then gradually compressed to D5. On the one hand, for the loading guide section, since D7 is larger than D5, under the premise of the same length, the cone angle of the device guide section 37 can be set smaller, so that the stent is easier to slide in the loading guide section 37; on the other hand, since the size of the stent is first compressed to D7 when it reaches the proximal end of the loading guide section, and is compressed to D5 when it continues to be pushed to the proximal end of the transition section 36, that is, the outer diameter size D0 of the stent is compressed to D5 after passing through the loading guide section and the transition section, and the deformation is relatively mild, which prevents the stent from being damaged or difficult to push in the loader due to the rapid increase of elastic restoring force caused by excessive compression deformation.

[0059] Fourth embodiment

[0060] The structure of the loader in this embodiment is basically the same as that of the loader in the previous embodiment, and the only difference is the structure of the transition section.

[0061] See also Figure 10-11As shown, the loader in this embodiment includes an introduction section 41, a first stage 45, a first protection section 42, a second protection section 43, a second stage 44, a transition section 46 and a loading guide section 47 connected in sequence. The second stage 44 is used to realize the connection between the second protection section 43 and the over-section section 46. It should be noted that the drawings in this embodiment are only exemplary and do not mean that the loader structure in this embodiment is limited to the structure in the drawings. This embodiment is based on the first to third embodiments, and the structure of the second stage 44 is improved. For example, in this embodiment, the loader structure of the first embodiment can be used as a basis, that is, the loader does not have a over-section section at this time, or the loader structure of the second embodiment can be used as a basis, and the loader has a straight over-section section at this time, or the loader structure of the third embodiment can be used as a basis, and the over-section section of the loader is a tapered tube section at this time. Of course, in this embodiment, the introduction section 41 and the first stage 45 can also be omitted, and the loader structure in this embodiment is not exhaustively listed here. In this embodiment, any one of the structures of the first to third embodiments can be used as a basis for improvement.

[0062] Specifically, in this embodiment, the second stage 44 is an arc-shaped pipe segment, that is, the second protection segment 43 realizes the transition with the transition segment 46 through the second stage 44 which is a curved pipe segment. Specifically, in the cross section formed by the second stage 44 along the axial direction, the inner wall of the second stage 44 is curved, and the curve form can be a circular arc or an elliptical arc or other curved shapes. The second stage 44 can be formed separately and then fixedly connected with the second protection segment 43, or the end of the second protection segment 43 can be rounded or bent into other shapes to obtain the second stage 44.

[0063] See also Fig.10 As shown, the sheath tube 100a in this embodiment includes a main body 101a and a distal end 102a disposed at the end of the main body 101a. Unlike the distal end in other embodiments which is a tapered tube, the distal end 102a in this embodiment is curved with the inner diameter gradually decreasing toward the distal end. Therefore, in this embodiment, the second stage 44 is set to a curved shape that matches the shape of the distal end 102, so that the loader 40 can better match the sheath tube 100a. In addition to the loader 40 in this embodiment, Fig.10 In addition to being matched with the sheath tube 100a in the figure, it can also be matched with the sheath tube 100 whose distal end is a tapered straight tube in other embodiments. Therefore, setting the second stage 44 as a curved section can enhance the adaptability of the loader 40 and be used in conjunction with sheath tubes of various shapes. In addition, since the second stage 44 is a curved section, a smooth transition between the second protection section 43 and the transition section 46 can be achieved, reducing the stress concentration of the loader 40 at the second stage.

[0064] Fifth embodiment

[0065] The structure of the loader in this embodiment is basically the same as that of the loader in the previous embodiment, and the only difference is the structure of the second protection section.

[0066] See also Figure 12-13 As shown, the loader in this embodiment is illustrated based on the loader in the second embodiment. Of course, the loader in this embodiment is not limited to the second embodiment, but can also be based on the first to fourth embodiments, as long as there is no technical conflict. The loader 50 includes an introduction section 51, a first stage 55, a first protection section 52, a second protection section 53, a second stage 54, a transition section 56 and a loading guide section 57 connected in sequence. Among them, a plurality of anti-skid protrusions 531 arranged at intervals along the axial direction are arranged on the inner wall of the second protection section. For each anti-skid protrusion 531, it is a closed ring in the circumferential direction. In other embodiments, the anti-skid protrusion 531 may not be arranged as a closed ring in the circumferential direction, that is, the angle of its distribution on the circumference is less than 360 degrees. In addition, in other embodiments, a plurality of anti-skid protrusions 531 may also be arranged at intervals in the circumferential direction, and a plurality of protection protrusions 531 are arranged around the inner wall of the second protection section 53 in the circumferential direction.

[0067] See also Fig.12 As shown, when the loader 50 is matched with the sheath tube 100, the second protection segment 53 is interference-fitted with the distal end portion 102 of the sheath tube 100, and the anti-slip protrusion 531 will abut against the outside of the distal end portion 102 to achieve matching. The existence of the anti-slip protrusion 531 increases the friction between the second protection segment 53 and the distal end portion 102, and can prevent the loader 50 and the sheath tube 100 from sliding relative to each other during the process of the stent passing through the loader and entering the sheath tube, thereby hindering the stent from entering the sheath.

[0068] Sixth embodiment

[0069] In this embodiment, the manufacturing method of the loader structure involved in the second embodiment is used for explanation. In this embodiment, the loader is manufactured by putting a heat shrink tube on the heat shrink rod assembly. Fig.14 As shown, the heat shrink tube 400 is sleeved on the outer circumference of the heat shrink rod assembly 200, and the heat shrink rod assembly 200 constitutes a forming mold of the loader; the heat shrink tube 400 is heated along the axial direction and the circumferential direction by a hot air gun 300, so that the heat shrink tube 400 is heat-shrunk and attached to the heat shrink rod assembly, and the loader for auxiliary stent sheathing is obtained. The heat shrink rod assembly 200 includes a first heat shrink rod 201 and a second heat shrink rod 202, which cooperate to form the heat shrink rod assembly 200.

[0070] See also Fig.15As shown, the first heat shrink rod 201 is rod-shaped as a whole, and includes a first straight section 2011, a first tapered section 2012, a step transition section 2013 and a second straight section 2014 which are connected in sequence. The first straight section 2011 is cylindrical as a whole, and its axis constitutes the axis of the first heat shrink rod 201, and has a free end face. The end of the first straight section 2011 away from the free end face is connected to the tapered section 2012, and the diameter of the tapered section 2012 gradually decreases in the direction away from the free end face until it is reduced to the minimum and then connected to the second straight section 2014 through the step transition section 2013. The outer diameter of the second straight section 2014 is smaller than the minimum outer diameter of the tapered section 2012, and a step transition section 2013 is formed at the connection between the two. A connecting rod 2015 is arranged on the end face of the second straight section 2014 away from the free end face.

[0071] See also Fig.16 As shown, the second heat shrink rod 202 includes a second tapered section 2022 and a third straight section 2021 connected in sequence. The diameter of the second tapered section 2022 gradually increases in a direction close to the third straight section 2021 until it is equal to the third straight section 2021. A connecting groove 2023 that cooperates with the connecting rod 2015 is provided on one side of the second tapered section 2022 away from the third straight section 2021. By inserting the connecting rod 2015 into the connecting groove 2023, the first heat shrink rod 201 and the second heat shrink rod 202 can be combined into a heat shrink rod assembly 200.

[0072] In this embodiment, a heat shrink tube 400 is used as the raw material to manufacture the loader. The heat shrink tube is low in cost and easy to tear. After the stent is sheathed, the loader made of the heat shrink tube can be directly torn and removed. The material of the heat shrink tube can be selected from polymer materials such as FEP, PTFE, PET, PE, PVC, etc. The inner diameter size and heat shrinkage ratio of the heat shrink tube should meet certain requirements. In one embodiment, the outer diameter D1 of the sheath tube 100 is 10F (i.e., 3.28±0.1mm), and the heat shrink tube uses an FEP tube with an inner diameter of 4.0±0.3mm before heat shrinkage, a wall thickness of 0.2±0.05mm, and a shrinkage ratio of 1.3:1.

[0073] The following is a description of the processing method of manufacturing a loader using the heat shrink rod assembly 200 in this embodiment. Fig.14As shown, the first heat shrink rod 201 and the second heat shrink rod 202 are assembled to form a heat shrink rod assembly 200; the heat shrink tube 400 is sleeved on the heat shrink rod assembly 200 so that its two ends are in suitable positions of the heat shrink rod assembly 200, and the specific positions can be determined according to the expected shape and size of the loader. In one embodiment, one end of the heat shrink tube is in the first straight section 2011, and the other end is in the second tapered section 2022. A hot air gun is set at a certain distance from the outer surface of the heat shrink tube 400, and the working temperature of the hot air gun is adjusted to a certain temperature. The distance between the hot air gun 300 and the outer surface of the heat shrink tube 400 and its working temperature can be determined according to the material properties and processing requirements of the heat shrink tube, for example, the above distance can be 3-5mm, and the above temperature can be 150-250 degrees. Then, the heat shrink rod assembly 200 is rotated at a uniform speed to drive the heat shrink tube 400 to rotate, so that the heat shrink tube 400 is heated evenly in the circumferential direction; at the same time, the hot air gun 300 moves along the axial direction of the heat shrink tube 400, so that the heat shrink tube 400 is heated in the entire axial direction.

[0074] See also Fig.17 As shown, the heat shrinkable tube 400 heated in the circumferential and axial directions will shrink and fit on the heat shrinkable rod assembly 200, and the shape of the heat shrinkable tube after shrinkage matches the heat shrinkable rod assembly 400, and its inner wall surface fits with the corresponding outer circumferential surface of the heat shrinkable rod assembly 200, that is, the heat shrinkable rod assembly constitutes a forming mold for the heat shrinkable tube. When the heat shrinkable tube 400 is cooled and shaped, the first heat shrinkable rod 201 is separated from the second heat shrinkable rod 202, and then the heat shrinkable tube is removed from the first heat shrinkable rod 201, and the manufactured loader can be obtained.

[0075] The shape of the loader processed in this embodiment is the same as the structure in the first embodiment, and does not have an introduction section and a first stage. Optionally, a corresponding structure can be set on the first straight section 2011 of the first heat shrink rod 201 to manufacture a loader with an introduction section and a first stage. In other embodiments, the shapes of the first heat shrink rod and the second heat shrink rod and the position of the heat shrink tube on the heat shrink rod assembly can also be changed to manufacture a loader of any shape in embodiments 1-5, and the detailed process will not be repeated here.

[0076] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are 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.

[0077] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A loader for assisting stent insertion into a sheath tube, characterized in that: The loader is detachably loaded on the sheath tube and comprises: The first protection segment has a cylindrical lumen and a protection segment inner diameter D4; A second protection segment, the lumen of which is conical and the large end side of which is connected to the first protection segment; A loading introduction section, the lumen of which is conical, and the small end side is connected to the small end side of the second protection section through a second stage; The inner diameter D4 of the protection section is larger than the maximum outer diameter D1 of the sheath tube, and the minimum diameter D5 of the second stage is smaller than the minimum inner diameter D2 of the sheath tube.

2. The loader for assisting stent sheathing according to claim 1, characterized in that: A transition section is further provided between the second stage and the loading introduction section. The inner cavity of the transition section is cylindrical and its inner diameter is equal to the minimum diameter D5 of the second stage.

3. The loader for assisting stent sheathing according to claim 1, characterized in that: A transition section is provided between the second stage and the loading introduction section. The inner cavity of the transition section is conical, and its minimum inner diameter is equal to the minimum diameter D5 of the second stage, and its maximum inner diameter is smaller than the maximum diameter D6 of the loading introduction section.

4. The auxiliary stent sheathing loader according to any one of claims 1 to 3, characterized in that: The inner cavity of the second stage is conical.

5. The loader for assisting stent sheathing according to any one of claims 1 to 3, characterized in that: The second stage forms a cross section along its axial direction, and the inner wall of the second stage is a curved segment in the cross section.

6. The loader for assisting stent sheathing according to any one of claims 1 to 3, characterized in that: An anti-slip protrusion is arranged on the inner wall of the second protection section.

7. The loader for assisting stent sheathing according to any one of claims 1 to 3, characterized in that: The loader further comprises an introduction section, wherein the introduction section is connected to the first protection section via a first stage, and a minimum inner diameter of the introduction section is greater than an inner diameter of the first protection section.

8. The loader for assisting stent sheathing according to any one of claims 1 to 3, characterized in that: The inner diameter D4 of the protection section and the maximum outer diameter D1 of the sheath tube satisfy 1.02D1≤D4≤1.12D1.

9. The loader for assisting stent sheathing according to any one of claims 1 to 3, characterized in that: The minimum diameter D5 of the second stage and the minimum inner diameter D2 of the sheath tube satisfy 0.96D2≤D5≤0.98D2.

10. A method for manufacturing the loader for assisting stent sheathing according to claims 1 to 9, characterized in that: The method comprises: Sleeve the heat shrink tube on the outer periphery of the heat shrink rod assembly, and the heat shrink rod assembly constitutes the forming mold of the loader; The heat shrinkable tube is heated so that the heat shrinkable tube is shrunk and attached to the heat shrinkable rod assembly.

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