Laser catheter and preparation method thereof

Abstract

The invention relates to a laser catheter which comprises an outer sheath tube, an optical fiber bundle and a guide wire tube, 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 and the guide wire tube at the far end of the laser catheter are fixed through filling glue; metal powder is mixed in the glue, the area filled with the glue is a first developing area, and the glue mixed with the metal powder has the developing effect under X rays. The invention further discloses a preparation method of the laser catheter. The preparation method comprises the steps of S1, glue mixing; s2, injecting glue; s3, curing is conducted; and S4, grinding. A traditional developing ring is replaced by doping the metal powder in the glue at the far end of the laser catheter, and therefore the risk that the developing ring falls off is eradicated. In the glue injection process, the silica gel cap is adopted to be matched with the dispensing machine for glue injection operation, the silica gel cap can prevent glue from flowing out to guarantee the clean environment, the dispensing machine can accurately control the glue outlet amount, then the length of the curing area of the far-end working area is guaranteed, and therefore the passing ability of the catheter is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of laser ablation, and in particular relates to a laser catheter 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 conventional 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 remain in the blood vessel and cause medical accidents. Therefore, it is necessary to improve the structure of the laser catheter. Summary of the invention

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

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

[0010] A laser catheter comprises an outer sheath tube, an optical fiber bundle and a wire guide tube, 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 and the wire guide tube at the distal end of the laser catheter are fixed by filling glue; the glue is mixed with metal powder, and the area filled with glue is a first developing area. The glue mixed with metal powder has the effect of developing under X-rays.

[0011] Furthermore, the metal powder is platinum-iridium alloy powder or platinum alloy powder or tantalum alloy powder, and the powder particle size does not exceed 25um.

[0012] Furthermore, the length of the first developing area is 2-3 mm.

[0013] Furthermore, a developing ring is provided between the guide wire tube and the outer sheath tube as a second developing area, and the developing ring is arranged at a position closer to the proximal end of the laser catheter than the first developing area.

[0014] Furthermore, the developing ring is a circumferentially unclosed structure, allowing deformation within a certain range.

[0015] A method for preparing a laser catheter comprises the following steps:

[0016] S1. Glue mixing: add metal powder into glue at a ratio of 100:1, then put into glue mixer for mixing and vacuum degassing;

[0017] S2, glue injection, inject the mixed glue into the glue dispenser, insert the assembled outer sheath tube assembly into the catheter hole of the silicone cap, and extend the optical fiber bundle and the wire guide tube out of the end of the outer sheath tube 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;

[0018] S3, curing, curing at room temperature for 24 hours;

[0019] S4, grinding, cutting off the excess glue and then grinding and polishing with a grinder to ensure that the end face of the optical fiber bundle is free of damage and scratches, thereby obtaining a first developing area.

[0020] Furthermore, the metal powder in S1 is a platinum-iridium alloy powder or a platinum alloy powder or a tantalum alloy powder with a particle size not exceeding 25 um; and the glue in S1 is an epoxy resin glue.

[0021] Furthermore, the silicone cap used in S2 is elastic, and the inside of the silicone cap is a glue injection space; the silicone cap is provided with a catheter 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 outer sheath and the core shaft, ensuring that the glue does not flow out from these two openings.

[0022] The injection hole is tilted and connected to the injection space. Although the needle of the glue dispenser will be pulled out of the injection hole after the glue is injected, the 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 diameter of the injection hole. In addition, the high viscosity of the glue can ensure that the glue will not overflow from the injection hole.

[0023] Furthermore, the needle of the glue dispensing machine has a diameter of 0.2-0.5 mm, and the glue injection hole has a diameter of 0.1-0.3 mm.

[0024] Further, the outer sheath tube assembly in S2 is composed of an outer sheath tube, an optical fiber bundle and a guide wire tube; or the outer sheath tube assembly in S2 is composed of an outer sheath tube, an optical fiber bundle, a guide wire tube and a developing ring, and the developing ring is located on the proximal side of the first developing area.

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

[0026] 1. The present invention replaces the traditional developing ring by doping metal powder into the glue at the distal end of the laser catheter, thereby eliminating the risk of the developing ring falling off.

[0027] 2. The present invention further improves the visibility of the laser catheter in the angiography by setting two developing areas, namely the first developing area and the second developing area, and has little effect on the passability of the laser catheter.

[0028] 3. 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

[0029] Figure 1 This is a schematic diagram of the overall structure of a conventional laser ablation catheter;

[0030] Figure 2 This is a schematic diagram of the structure of the distal working area of ​​a conventional laser ablation catheter;

[0031] Figure 3 is a schematic diagram of the structure of a remote working area according to Embodiment 1 of the present invention;

[0032] Figure 4 is a schematic diagram of the cross-sectional structure of the remote working area of ​​Example 1 of the present invention;

[0033] Figure 5 It is a schematic flow chart of the preparation method of the present invention;

[0034] Figure 6 It is a three-dimensional schematic diagram of the glue injection process;

[0035] Figure 7 It is a schematic diagram of the cross-sectional structure of the semi-finished product before glue injection;

[0036] Figure 8 is a schematic diagram of the cross-section of the silicone cap structure;

[0037] Fig. 9 is a schematic diagram of the structure of a developing ring according to Embodiment 2 of the present invention;

[0038] Fig.10 2 is a schematic diagram of the structure in which the developing ring of Embodiment 2 of the present invention is located on the outer wall of the wire guide tube;

[0039] Fig.11 is a schematic structural diagram of a developing ring located on the inner wall of an outer sheath tube according to Embodiment 2 of the present invention;

[0040] In the figure, 1-outer sheath; 2-optical fiber bundle; 3-guide wire tube; 4-glue; 5-core shaft; 6-silicone cap; 601-catheter hole; 602-glue injection hole; 603-core shaft hole; 604-glue injection space; 7-developing ring. DETAILED DESCRIPTION

[0041] 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.

[0042] Example 1: See attached Figure 3-4A laser catheter comprises an outer sheath tube 1, an optical fiber bundle 2 and a guide wire tube 3, wherein the guide wire 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 guide wire tube 3. The outer sheath tube 1, the optical fiber bundle 2 and the guide wire tube 3 at the distal end of the laser catheter are fixed by filling glue 4; the glue 4 is mixed with metal powder, and the area filled with glue is the first developing area, and the glue 4 mixed with metal powder has the effect of developing under X-rays. The length of the first developing area is 2-3mm. Preferably, the metal powder is platinum-iridium alloy powder, and the powder particle size does not exceed 25um. Tantalum alloy powder or tantalum alloy powder or other alloys with high density and can be irradiated by X-rays can also be selected.

[0043] See attached Figure 5-8 , a method for preparing a laser catheter, comprising the following steps:

[0044] S1, glue mixing, adding metal powder to glue at a ratio of 100:1, then putting it into a glue mixer for mixing and vacuum degassing to obtain glue 4 mixed with metal powder; the metal powder in S1 is platinum-iridium alloy powder or platinum alloy powder or tantalum alloy powder with a particle size not exceeding 25um. The glue in S1 is epoxy resin glue.

[0045] S2, glue injection, inject the mixed glue 4 into the glue dispensing machine, insert the assembled outer sheath tube assembly into the catheter hole 601 of the silicone cap 6, in this example, the outer sheath tube assembly consists of an outer sheath tube 1, an optical fiber bundle 2 and a guide wire tube 3, wherein the optical fiber bundle 2 and the guide wire tube 3 of the outer sheath tube assembly extend out of the distal end of the outer sheath tube 1 for subsequent grinding; use the mandrel 5 to pass through the silicone cap 6 and the guide wire tube 3 in sequence, use the mandrel 5 to block the cavity in the center of the guide wire tube 3 to prevent the glue 4 from flowing into the guide wire tube 3 during glue injection, and use the glue dispensing machine to inject the glue 4 into the glue injection space 604 of the silicone cap 6;

[0046] S3, curing, placing the outer sheath tube assembly after the injection obtained in step S2 at room temperature and curing for 24 hours;

[0047] S4, 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, thereby obtaining a first developing area.

[0048] The silicone cap 6 used in S2 is elastic, and the inside of the silicone cap 6 is a glue injection space 604. The silicone cap 6 is provided with a catheter hole 601 at one end and a core shaft 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 catheter hole 601 and the core shaft hole 603 will firmly lock the outer sheath 1 and the core shaft 5 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 size of the glue dispenser needle is 0.2-0.5mm in diameter, and the diameter of the glue injection hole 602 is 0.1-0.3mm. Although the glue dispenser needle will be pulled out of the glue injection hole 602 after the glue is injected, since the size of the glue dispenser needle and the glue injection hole 602 is very small, the rebound of the silicone itself after the needle is pulled out 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.

[0049] Example 2: See attached Figure 9-11 , a laser catheter, the other structures are basically the same as those in Example 1. Further, the laser catheter in this example also has a second developing area, which is closer to the proximal end than the first developing area, and the second developing area is a developing ring 7 located outside the guide wire tube 3 and inside the outer sheath tube 1. Preferably, the interval between the first developing area and the second developing area is 5-10 mm.

[0050] The developing ring 7 is located between the optical fiber bundle 2 and the wire guide tube 3, and is sleeved on the wire guide tube 3, that is, the inner wall of the developing ring 7 is close to the outer wall of the wire guide tube 3; or it is located between the optical fiber bundle 2 and the outer sheath tube 1, that is, the outer wall of the developing ring 7 is close to the inner wall of the outer sheath tube 1; or it is located inside the optical fiber bundle 2, that is, a part of the optical fiber is located inside the developing ring 7 and the other part is located outside the developing ring 7.

[0051] Specifically, Fig. 9 As shown, the developing ring 7 is a notched structure, that is, a circumferentially unclosed structure, so a certain range of deformation is allowed; in this example, the outer sheath assembly is composed of an outer sheath 1, an optical fiber bundle 2, a guide wire tube 3 and a developing ring 7, and the developing ring 7 is located on the proximal side of the first developing area. Fig.10 Before manufacturing, the developing ring 7 can be shrunk in advance to be close to the wire guide tube 3, or it can be made as shown in FIG. Fig.11 As shown, the developing ring 7 is expanded to be close to the outer sheath tube 1, and then the laser catheter is made. At this time, the developing ring 7 is outside the guide wire tube 3 or inside the outer sheath tube 1. Even the developing ring 7 without a gap can be used, and the developing ring 7 is placed between the optical fiber bundles 2 before the glue is poured (not shown in the figure).

[0052] The distal working area of ​​the laser catheter uses glue doped with metal powder to achieve the development effect, avoiding the risk of the development ring falling off due to heat in the prior art; further, a second development area is set to cooperate with the first development area, so as to more accurately confirm the actual position of the laser catheter on the angiography image, and the development ring 7 of the second development area is located inside the outer sheath 1, and there is no risk of falling off.

[0053] 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, comprising an outer sheath tube, an optical fiber bundle and a guide wire tube, wherein the guide wire tube is arranged inside the outer sheath tube, and the optical fiber bundle is arranged between the outer sheath tube and the guide wire tube, wherein the outer sheath tube, the optical fiber bundle and the guide wire tube at the distal end of the laser catheter are fixed by filling glue, characterized in that: The glue is mixed with metal powder, and the area filled with the glue is the first developing area.

2. A laser catheter according to claim 1, characterized in that: The metal powder is platinum-iridium alloy powder or platinum alloy powder or tantalum alloy powder, and the powder particle size does not exceed 25um.

3. A laser catheter according to claim 1, characterized in that: The length of the first developing area is 2-3 mm.

4. A laser catheter according to claim 1, characterized in that: A developing ring is provided between the guide wire tube and the outer sheath tube as a second developing area, and the developing ring is arranged at a position closer to the proximal end of the laser catheter than the first developing area.

5. A laser catheter according to claim 4, characterized in that: The developing ring is a circumferentially unclosed structure.

6. A method for preparing a laser catheter, used for preparing the laser catheter as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Glue mixing: add metal powder to the glue at a ratio of 100:1, then put it into a glue mixer for mixing and vacuum degassing; S2. Glue injection: inject the mixed glue into a glue dispenser, insert the assembled outer sheath tube assembly into the catheter hole of the silicone cap, and extend the optical fiber bundle and the guide wire tube out of the far end of the outer sheath tube; use a core shaft to pass through the silicone cap to block the cavity in the center of the guide wire tube, and use a glue dispenser to inject glue into the glue injection space of the silicone cap; S3. Curing: cure at room temperature for 24 hours; S4, grinding, cutting off the excess glue and then grinding and polishing with a grinder to obtain a first developing area.

7. The method for preparing a laser catheter according to claim 6, characterized in that: The metal powder in S1 is platinum-iridium alloy powder or platinum alloy powder or tantalum alloy powder with a particle size not exceeding 25 um; the glue in S1 is epoxy resin glue.

8. The method for preparing a laser catheter according to claim 6, characterized in that: The silicone cap used in S2 is elastic, and the inside of the silicone cap is a glue injection space; a catheter hole is provided at one end of the silicone cap and a core shaft hole is provided at the other end, and 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.

9. The method for preparing a laser catheter according to claim 8, characterized in that: The needle of the glue dispensing machine has a diameter of 0.2-0.5 mm, and the diameter of the glue injection hole is 0.1-0.3 mm.

10. The method for preparing a laser catheter according to claim 6, characterized in that: The outer sheath tube assembly in S2 is composed of an outer sheath tube, an optical fiber bundle and a guide wire tube; or the outer sheath tube assembly in S2 is composed of an outer sheath tube, an optical fiber bundle, a guide wire tube and a developing ring, and the developing ring is located on the proximal side of the first developing area.

Images