Laser catheter with developing ring anti-falling structure and preparation method of laser catheter

Abstract

The invention relates to a laser catheter with a developing ring anti-falling structure, the laser catheter comprises an outer sheath tube, an optical fiber bundle, a guide wire tube and a developing ring, the guide wire tube is arranged in the outer sheath tube, the optical fiber bundle is arranged between the outer sheath tube and the guide wire tube, and the outer sheath tube, the optical fiber bundle, the guide wire tube and the developing ring at the far end of the laser catheter are fixed through filling glue. The far end of the outer sheath tube is connected with the near end of the developing ring; the developing ring is of a hollow conical structure, and the diameter of the far end is larger than that of the near end. The invention further discloses a preparation method of the laser catheter. The preparation method comprises the steps of S1, prefabricating the developing ring assembly; s2, combining the developing ring assembly with the outer sheath tube assembly; s3, injecting glue; s4, curing is conducted; and S5, grinding. The developing ring is designed to be trumpet-shaped, so that the developing ring is prevented from falling off; in the glue injection process, a silica gel cap is adopted to be matched with a dispensing machine for glue injection, the silica gel cap prevents glue from flowing out to guarantee the clean environment, the dispensing machine accurately controls the glue outlet amount, and then the length of the curing area of the far-end working area and the passability of the guide pipe are guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of laser ablation, and in particular relates to a laser catheter with a developing ring anti-stripping structure and a preparation method thereof. Background Art

[0002] Excimer Laser Coronary Atherectomy (ELCA) is an interventional technique used to treat coronary artery disease. It uses ultraviolet lasers of a specific wavelength to ablate plaques in the coronary arteries, thereby improving the patency of the blood vessels.

[0003] The principles of ELCA technology include photochemical effect, photothermal effect and photomechanical effect. The short wavelength of laser (308nm) can penetrate tissue and act precisely on plaques without damaging surrounding tissues. After the laser energy is absorbed by the plaque, it breaks the molecular bonds through photochemical action, generates steam bubbles through photothermal action, and generates kinetic energy through photomechanical action, breaking the plaque into tiny particles, which can be absorbed by the body, thereby reducing the blockage of blood vessels.

[0004] Compared with the earlier technology, the new generation of ELCA technology has a shorter wavelength, a thinner catheter design and a pulsed cold light source, which significantly improves its effectiveness and safety. It is suitable for the treatment of a variety of coronary artery lesions, including in-stent restenosis, chronic total occlusion lesions, calcified lesions, etc. In some lesions that are difficult to dilate with traditional balloons, ELCA technology can provide an effective treatment plan.

[0005] During the laser ablation procedure, the laser ablation catheter needs to be positioned. The traditional method is to equip the distal end of the laser catheter with a developing ring. The developing ring is a medical material used in interventional therapy. It serves as an X-ray developing mark in the distal working area and is used for positioning. The developing ring development principle is that objects of different densities absorb X-rays to different degrees under X-ray irradiation. This absorption difference leads to different X-ray intensities reaching the imaging plane, thereby forming an image with black and white contrast and layer differences on the X-ray film or fluorescent screen. This developing ring is a disposable medical material and is usually withdrawn from the human body with the catheter after the interventional therapy is completed, so it does not need to stay in the body for a long time. Since interventional therapy is usually minimally invasive, the catheters used are mostly soft plastics with very thin diameters, so the developing ring needs to have a very small size (millimeter or micrometer level), extremely thin thickness (usually tens of micrometers), extremely high dimensional accuracy, and good surface finish and plasticity, which makes the processing of the developing ring quite difficult.

[0006] In addition, this imaging ring structure also has safety risks. Figure 1As shown in FIG. 1 , it is composed of a proximal connector, a mid-end quick exchange port, and a distal working area. The proximal connector is responsible for receiving lasers, the mid-end quick exchange port is responsible for exchanging guidewires, and the distal working area is responsible for emitting lasers. Figure 2 As shown, the traditional developing ring is a thin-walled cylinder that is bonded to the catheter with glue. Once the glue falls off, there is a risk of falling off, which will cause major problems if working in a blood vessel at this time.

[0007] Since traditional laser ablation catheters mainly use glue to fix the imaging ring in the distal working area, there is a certain risk of the imaging ring structure falling off, which may cause the imaging ring to be retained in the blood vessel and cause medical accidents. Therefore, it is necessary to improve the structure of the laser catheter and add the corresponding design of the anti-falling structure. Summary of the invention

[0008] The present invention provides a laser catheter with a developing ring anti-falling structure and a preparation method thereof to solve the technical problems existing in the known technology, thereby reducing the risk of the developing ring falling off.

[0009] The present invention includes the following technical solutions:

[0010] A laser catheter with a developing ring anti-detachment structure comprises an outer sheath tube, an optical fiber bundle, a wire guide tube and a developing ring, wherein the wire guide tube is arranged inside the outer sheath tube, and the optical fiber bundle is arranged between the outer sheath tube and the wire guide tube. The outer sheath tube, the optical fiber bundle, the wire guide tube and the developing ring at the distal end of the laser catheter are fixed by filling glue; the distal end of the outer sheath tube is connected to the proximal end of the developing ring; the developing ring is a hollow conical structure, and the diameter of the distal end is larger than the proximal end. In this way, even if the developing ring and the glue are detached, the diameter of the glue filled in the distal end of the developing ring is larger than the minimum diameter of the developing ring, thereby limiting its displacement and preventing it from falling off.

[0011] Furthermore, a hollow structure is provided on the side wall of the developing ring, and a convex structure of glue is formed in the hollow structure after the glue is injected. The hollow structure further increases the bonding strength between the developing ring and the glue, and the convex structure of the glue is used to constrain the developing ring, thereby further preventing the developing ring from falling off.

[0012] Furthermore, the hollow structure is provided as one or more.

[0013] Furthermore, the shape of the hollow structure can be set to a regular shape or an irregular shape.

[0014] Furthermore, the outer sheath tube and the developing ring are fixed by snap fastening or by the cooperation of a protrusion and a groove.

[0015] A method for preparing a laser catheter having a developing ring anti-slip structure comprises the following steps:

[0016] S1, prefabricate the developing ring assembly, and use a tool to set the developing ring in the heat shrink tube;

[0017] S2, combining the developing ring assembly with the outer sheath assembly, the outer sheath assembly including the outer sheath, the optical fiber bundle and the guide wire tube; aligning the end face of the outer sheath assembly with the narrow end face of the developing ring to constrain the position of the developing ring, and then heating the heat shrink tube to fix the developing ring and the outer sheath to obtain an assembled assembly;

[0018] S3, glue injection, inject glue into the glue dispenser, insert the obtained assembly into the sleeve hole of the silicone cap, and the optical fiber bundle and the wire guide tube extend out of the far end of the developing ring for subsequent grinding; use the mandrel to pass through the silicone cap to block the cavity in the center of the wire guide tube to prevent the glue from flowing into the wire guide tube during glue injection, and use the glue dispenser to inject the glue into the glue injection space of the silicone cap;

[0019] S4, curing, curing at room temperature for 24 hours;

[0020] S5. Grinding. Cut off the excess glue and use a grinder to grind and polish to ensure that the end face of the optical fiber bundle is not damaged or scratched. Finally, remove the heat shrink tube to obtain the laser catheter.

[0021] Furthermore, a catheter hole is provided in the middle of the heat shrink tube in S1, and the diameter of the catheter hole is slightly larger than the outer diameter of the catheter, so as to facilitate the subsequent assembly with the catheter; the heat shrink tube in S1 is heated to fix it to the developing ring.

[0022] Furthermore, the glue in S3 is epoxy resin glue.

[0023] Furthermore, the silicone cap used in S3 is elastic, and the inside of the silicone cap is a glue injection space; the silicone cap is provided with a sleeve hole at one end and a core shaft hole at the other end, and a glue injection hole is provided on the side wall of the silicone cap. Since the silicone is elastic, the catheter hole and the core shaft hole will firmly lock the catheter and the core shaft to ensure that the glue does not flow out of these two holes. The glue injection hole is tilted and connected to the glue injection space. Although the needle of the glue dispenser will be pulled out of the glue injection hole after the glue is injected, the glue injection hole is also small because the needle of the glue dispenser is very small. After the needle is pulled out, the rebound of the silicone itself will further reduce the aperture of the glue injection hole, and the high viscosity of the glue can ensure that the glue will not overflow from the glue injection hole.

[0024] Furthermore, the glue extends from the distal end to the proximal end of the laser catheter, and is distributed over a length of 2-3 mm from the proximal end of the developing ring along the length direction of the laser catheter; the needle size of the glue dispenser is 0.2-0.5 mm in diameter, and the glue injection hole has a diameter of 0.1-0.3 mm.

[0025] The present invention has the advantages and positive effects:

[0026] 1. The present invention prevents the developer ring from falling off by designing it into a trumpet shape; even if the developer ring and the glue are separated, the diameter of the glue filled in the far end of the developer ring is larger than the minimum diameter of the developer ring, which limits its displacement and prevents it from falling off. In addition, the hollow structure on the developer ring can form a bulge after the glue is poured, further preventing it from falling off.

[0027] 2. The present invention uses a silicone cap in conjunction with a glue dispensing machine to perform the glue injection operation during the glue injection process. The silicone cap can prevent the glue from flowing out to ensure a clean environment. The glue dispensing machine can accurately control the amount of glue output, thereby ensuring the length of the curing area in the distal working area, thereby ensuring the passability of the catheter. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the overall structure of a conventional laser ablation catheter;

[0029] Figure 2 This is a schematic diagram of the structure of the distal working area of ​​a conventional laser ablation catheter;

[0030] Figure 3 is a schematic diagram of the remote work area structure of Example 1;

[0031] Figure 4 is a schematic diagram of the cross-sectional structure of the remote working area of ​​Example 1;

[0032] Figure 5 It is a schematic flow chart of the preparation method of the present invention;

[0033] Figure 6 is a schematic diagram of the cross-section of the silicone cap structure;

[0034] Figure 7 is a three-dimensional schematic diagram of the developing ring assembly in Example 1;

[0035] Figure 8 is a schematic cross-sectional structural diagram of the developing ring assembly in Example 1;

[0036] Fig. 9 is a three-dimensional schematic diagram of the glue injection process of Example 1;

[0037] Fig.10 This is a schematic diagram of the cross-sectional structure of the semi-finished product before glue injection in Example 1;

[0038] Fig.11 is a three-dimensional schematic diagram of the developing ring assembly in Example 2;

[0039] In the figure, 1-outer sheath; 2-optical fiber bundle; 3-wire guide tube; 4-glue; 5-core shaft; 6-silicone cap; 601-casing hole; 602-glue injection hole; 603-core shaft hole; 604-glue injection space; 7-developing ring; 701-hollow structure; 8-heat shrink tube; 801-catheter hole. DETAILED DESCRIPTION

[0040] In order to further disclose the content, features and effects of the present invention, the following examples are given and described in detail with reference to the accompanying drawings.

[0041] Example 1: See attached Figure 3-4 A laser catheter with a developing ring anti-detachment structure comprises an outer sheath tube 1, an optical fiber bundle 2, a wire guide tube 3 and a developing ring 7, wherein the wire guide tube 3 is arranged inside the outer sheath tube 1, and the optical fiber bundle 2 is arranged between the outer sheath tube 1 and the wire guide tube 3; the outer sheath tube 1, the optical fiber bundle 2, the wire guide tube 3 and the developing ring 7 at the distal end of the laser catheter are fixed by filling glue 4; the length of the glue 4 distributed from the proximal end of the developing ring 7 along the length direction of the outer sheath tube 1 to the proximal end is 2-3 mm. The distal end of the outer sheath tube 1 is connected to the proximal end of the developing ring 7, and the developing ring 7 is a hollow conical structure, and its distal end diameter is larger than the proximal end diameter. In this way, even if the developing ring 7 and the glue 4 are detached, the diameter of the glue 4 filled in the distal end of the developing ring 7 is larger than the minimum diameter of the developing ring 7, thereby limiting its displacement and preventing it from falling off.

[0042] The following optional schemes are not illustrated in this example. Furthermore, in order to improve the reliability of the connection between the developing ring 7 and the outer sheath tube 1, the developing ring 7 and the outer sheath tube 1 can be connected by means of a protrusion and a groove. Specifically, the proximal end of the developing ring 7 is provided with an annular protrusion, and the distal end of the outer sheath tube 1 is provided with an annular groove; or vice versa, the proximal end of the developing ring 7 is provided with an annular groove, and the distal end of the outer sheath tube 1 is provided with an annular protrusion.

[0043] Alternatively, the developing ring 7 is connected to the outer sheath tube 1 by a snap-fit ​​connection.

[0044] See attached Figure 5-10 A method for preparing a laser catheter having a developing ring anti-detachment structure comprises the following steps:

[0045] S1, prefabricate the developing ring assembly, use a tool to place the developing ring 7 in the heat shrink tube 8, heat the heat shrink tube 8 at a first temperature and a first duration to fix it to the developing ring 7, and obtain the following Figure 7-Figure 8 The structure shown; the heat shrink tube 8 in S1 is provided with a catheter hole 801 in the middle, and the first temperature and the first duration are controlled so that the catheter hole 801 after heating can not only ensure that the developing ring 7 is fixed but also ensure that its diameter is slightly larger than the outer diameter of the outer sheath tube 1, which is convenient for subsequent assembly with the outer sheath tube assembly. The outer sheath tube assembly includes an outer sheath tube 1, an optical fiber bundle 2 and a guide wire tube 3. When assembling the developing ring 7 and the heat shrink tube 8, try to make the wide end of the developing ring 7 flush with the heat shrink tube 8 to facilitate subsequent processing; or after the assembly is completed, cut off the excess part of the heat shrink tube 8 near the wide end.

[0046] S2, combining the developing ring assembly with the outer sheath assembly, inserting the outer sheath assembly from the end of the heat shrink tube close to the narrow opening of the developing ring until the end surface of the outer sheath tube 1 is aligned with the narrow opening end surface of the developing ring 7, thereby constraining the position of the developing ring 7, and further heating the heat shrink tube 8 at a second temperature and a second duration to further reduce the size of the heat shrink tube, so that the developing ring 7 is fixed to the outer sheath tube 1, and an assembly component is obtained;

[0047] S3, glue injection, inject glue 4 into the glue dispenser, insert the assembly with the heat shrink tube 8 on the outside into the sleeve hole 601 of the silicone cap 6, and the optical fiber bundle 2 and the wire guide tube 3 extend out of the far end of the developing ring 7 for subsequent grinding; use the mandrel 5 to pass through the silicone cap 6 and the wire guide tube in turn, use the mandrel 5 to block the cavity in the center of the wire guide tube 3 to prevent the glue 4 from flowing into the wire guide tube 3 during glue injection, and use the glue dispenser to inject the glue 4 into the glue injection space 604 of the silicone cap 6; the glue 4 in S3 is epoxy resin glue. At the same time, it is necessary to pay attention to not inject too much glue during the glue injection process, refer to Fig.10 The glue injection cut-off surface shown is sufficient, because the laser catheter needs to have a certain passability, and the reduced flexibility of the glue injection area will reduce the passability of the catheter 1, so the smaller the glue injection area, the better. Preferably, the cut-off surface is 2-3mm extending from the narrow end of the developing ring 7, that is, the proximal end to the proximal end.

[0048] S4, curing, placing the component after the injection obtained in step S3 at room temperature for curing for 24 hours;

[0049] S5, grinding, cutting off the excess glue 4 and then grinding and polishing with a grinder to ensure that the end face of the optical fiber bundle 2 is free of damage and scratches, and finally removing the heat shrink tube 8 to obtain the laser catheter in the above embodiment. The heat shrink tube 8 can be removed by hand tearing or other methods.

[0050] The silicone cap 6 used in S3 is elastic, and the inside of the silicone cap 6 is a glue injection space 604. The silicone cap 6 is provided with a sleeve hole 601 at one end and a mandrel hole 603 at the other end, and a glue injection hole 602 is provided on the side wall of the silicone cap 6. Since the silicone is elastic, the sleeve hole 601 and the mandrel hole 603 will firmly lock the outer sheath tube 1 and the mandrel 5 wrapped with the heat shrink tube 8 to ensure that the glue 4 does not flow out from these two ports. The glue injection hole 602 is tilted and connected to the glue injection space 604. The diameter of the glue dispenser needle is 0.2-0.5mm, and the diameter of the glue injection hole 602 is 0.1-0.3mm. Although the glue dispenser needle will be pulled out from the glue injection hole 602 after glue injection, the glue dispenser needle is very small, so the glue injection hole 602 is also very small. After the needle is pulled out, the rebound of the silicone itself will further reduce the aperture of the glue injection hole 602, and the high viscosity of the glue 4 can ensure that the glue 4 will not overflow from the glue injection hole 602.

[0051] The above preparation method uses heat shrink tube 8 as an intermediate medium, which can fix the relative position relationship between the developing ring 7 and the outer sheath tube assembly on the one hand, and protect the developing ring 7, the outer sheath tube 1, the optical fiber bundle 2, etc. during the preparation process on the other hand.

[0052] Example 2: See attached Fig.11 , a laser catheter with a developing ring anti-detachment structure, the other structures are basically the same as those in Example 1.

[0053] In this example, a hollow structure 701 is provided on the side wall of the developing ring 7, and a convex structure of glue is formed in the hollow structure 701 after the glue is injected. The bonding strength between the developing ring 7 and the glue 4 is further increased by the hollow structure 701, and the convex structure of the glue 4 is relied on to constrain the developing ring 7, further preventing the developing ring 7 from falling off. In this example, the hollow structure 701 is set to be multiple, and the shape is set to be a regular circle. The shape of the hollow structure 701 can also be set to an irregular shape. The shapes of the multiple hollow structures 701 can be the same or different.

[0054] Although the preferred embodiments of the present invention are described above, the present invention is not limited to the above specific embodiments, which are merely illustrative and not restrictive. Under the guidance of the present invention, a person skilled in the art can make many forms without departing from the scope of the present invention and the claims. All of these belong to the protection scope of the present invention.

Claims

1. A laser catheter with a developing ring anti-detachment structure, comprising an outer sheath tube, an optical fiber bundle, a wire guide tube and a developing ring, wherein the wire guide tube is arranged inside the outer sheath tube, and the optical fiber bundle is arranged between the outer sheath tube and the wire guide tube. The outer sheath tube, the optical fiber bundle, the wire guide tube and the developing ring at the distal end of the laser catheter are fixed by filling glue, characterized in that: The distal end of the outer sheath is connected to the proximal end of the developing ring; the developing ring is a hollow conical structure, and the diameter of the distal end is larger than that of the proximal end.

2. The laser catheter with a developing ring anti-detachment structure according to claim 1, characterized in that: A hollow structure is arranged on the side wall of the developing ring, and a convex structure of glue is formed in the hollow structure after the glue is injected.

3. The laser catheter with a developing ring anti-detachment structure according to claim 2, characterized in that: The hollow structure is provided in one or more forms.

4. The laser catheter with a developing ring anti-detachment structure according to claim 2, characterized in that: The shape of the hollow structure is regular or irregular.

5. The laser catheter with a developing ring anti-detachment structure according to claim 1, characterized in that: The outer sheath tube and the developing ring are also fixed by snap fastening or by the cooperation of a protrusion and a groove.

6. A method for preparing a laser catheter having a developing ring anti-detachment structure, characterized in that: The following steps are involved: S1. Prefabricate the developing ring assembly, and use the tooling to set the developing ring in the heat shrink tube; S2. Combine the developing ring assembly with the outer sheath tube assembly, which includes the outer sheath tube, the optical fiber bundle and the guide wire tube; overlap the end face of the outer sheath tube assembly with the narrow end face of the developing ring, and then heat the heat shrink tube to fix the developing ring and the outer sheath tube to obtain an assembled assembly; S3. Glue injection, inject glue into the glue dispenser, insert the assembly assembly into the sleeve hole of the silicone cap, and the optical fiber bundle and the guide wire tube extend out of the far end of the developing ring; use the mandrel to pass through the silicone cap to block the cavity in the center of the guide wire tube, and use the glue dispenser to inject glue into the glue injection space of the silicone cap; S4, curing, curing at room temperature for 24 hours; S5, grinding, cutting off excess glue and then grinding and polishing with a grinder, and finally removing the heat shrink tube to obtain the laser catheter as described in any one of claims 1-5.

7. The method for preparing a laser catheter having a developing ring anti-detachment structure according to claim 6, characterized in that: The heat shrink tube in S1 is provided with a conduit hole in the middle, and the diameter of the conduit hole is larger than the outer diameter of the conduit; the heat shrink tube in S1 is heated to fix it to the developing ring.

8. The method for preparing a laser catheter having a developing ring anti-detachment structure according to claim 6, characterized in that: The glue in S3 is epoxy resin glue.

9. The method for preparing a laser catheter having a developing ring anti-detachment structure according to claim 6, characterized in that: The silicone cap used in S3 is elastic, and the interior of the silicone cap is a glue injection space. A sleeve hole is provided at one end of the silicone cap and a core shaft hole is provided at the other end. A glue injection hole is provided on the side wall of the silicone cap; the glue injection hole is inclined and connected to the glue injection space.

10. The method for preparing a laser catheter having a developing ring anti-detachment structure according to claim 6, characterized in that: The glue extends from the distal end to the proximal end of the laser catheter, and is distributed over a length of 2-3 mm from the proximal end of the developing ring along the length direction of the laser catheter; the needle size of the glue dispenser is 0.2-0.5 mm in diameter, and the glue injection hole has a diameter of 0.1-0.3 mm.

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