Method of making a catheter and catheter

Abstract

A method for manufacturing a catheter includes: a disposing step of disposing a braided body (16) having a first wire and a second wire crossing the first wire on an outer peripheral surface of an inner member; a covering step of covering an outer peripheral side of the braided body (16) with a covering member (34) that allows laser to pass therethrough; a cutting step of irradiating laser (60) from an outer side of the covering member (34) to a portion of one of the first wire (17) and the second wire (18) of the braided body (16) that is on a front end side of a crossing portion (19), and cutting the one wire; and a removing step of removing the covering member (34) from the outer peripheral side of the braided body (16).

Description

Technical Field

[0001] This invention relates to a method for manufacturing a catheter and to a catheter. Background Technology

[0002] Catheters have traditionally been used for inserting into tubular organs such as blood vessels within the body. A catheter typically has the following structure: an inner layer, a braided body disposed on the outer periphery of the inner layer, and an outer layer disposed on the outer periphery of the braided body; alternatively, a braided body may be disposed on the inner periphery of the outer layer instead of an inner layer. The braided body functions as a reinforcing material and is formed by weaving together metal threads made of tungsten or stainless steel. The braided body consists of multiple first threads and multiple second threads intersecting the first threads. After weaving the multiple first and second threads, the excess portions of each thread are cut off and removed, thus forming the two ends of the braided body. Patent Document 1 describes a method for manufacturing a catheter in which the excess portions of the first and second threads are cut off by irradiating them with a laser. Patent Document 1 also describes forming a raised portion by irradiating the sharp remaining portion produced by this cutting with a laser again.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 6080258 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the conduit manufactured by the method described in Patent Document 1, the first and second threads are irradiated with a laser to cut off excess portions. In this process, the first and second threads are actually liquefied due to the heat from the laser, and there is a high probability that the surface tension at this point will cause rounded bulges to form. Furthermore, in the manufacturing method described in Patent Document 1, since the cut portions are further irradiated with a laser to form larger bulges, the thickness of the leading edge of each thread may be greater than the thickness of the intersection adjacent to that leading edge. When the thickness of the leading edge of each thread increases and its radially outer end is radially outer than the intersection, it is necessary to increase the thickness of the outer layer to prevent the braid from protruding from the outer peripheral surface of the outer layer. This causes localized changes in the radial position of the outer peripheral surface of the outer layer, potentially making it radially uneven.

[0008] The object of the present invention is to suppress the increase in thickness of the front end of the braid relative to the thickness of the intersection of each thread in the method of manufacturing the catheter and the catheter, and to suppress radial unevenness of the outer peripheral surface of the outer layer.

[0009] Methods for solving problems

[0010] The method for manufacturing a catheter according to the present invention comprises: a braid having a first thread and a second thread intersecting the first thread; and an outer layer disposed on the outer periphery of the braid; the method comprising: a placement step of placing the braid on the cylindrical outer peripheral surface of an inner component; a covering step of covering the outer peripheral side of the braid with a covering member that allows laser transmission; a cutting step of irradiating a portion of at least one of the first and second threads in the braid, near the front end of the intersection, with a laser from the outside of the covering member to cut the one thread; and a removal step of removing the covering member from the outer peripheral side of the braid.

[0011] According to the above structure, it is possible to prevent the thickness of the leading edge of one thread from becoming greater than the thickness of the intersection of the first and second threads due to laser irradiation during cutting. Therefore, it is not necessary to increase the thickness of the outer layer of the guide tube to prevent the braid from protruding from the outer peripheral surface of the outer layer, and radial unevenness on the outer peripheral surface of the outer layer can be suppressed.

[0012] In the method for manufacturing the catheter of the present invention, it is possible to configure the method such that, in the cutting step, a laser is irradiated from the outside of the covering member onto the portion of at least one of the first and second threads in the braid that is closer to the front end than the intersection, cutting the first thread, and welding the first and second threads.

[0013] According to the above structure, it is possible to prevent the thickness of the leading edge of one wire from becoming greater than the thickness of the intersection of the first and second wires due to laser irradiation during cutting. Furthermore, it is possible to weld the first and second wires simultaneously with cutting one wire. Moreover, it is not necessary to pre-join the first and second wires at the intersection by laser irradiation before cutting them by laser irradiation. Therefore, the number of laser irradiations can be reduced.

[0014] In the method for manufacturing the catheter of the present invention, it is possible to configure the cutting process in which, from the outside of the covering member, a laser is irradiated onto the portion of one of the braids that is closer to the front end of the cross section and the other of the first and second threads, thereby cutting the one of the braids and welding the first and second threads.

[0015] According to the above structure, it is possible to prevent the thickness of the leading edge of one wire from becoming greater than the thickness of the intersection of the first and second wires due to laser irradiation during cutting. Furthermore, after the first and second wires have melted, the solidified portion further enhances the bonding strength between the first and second wires.

[0016] In the method for manufacturing the catheter of the present invention, the covering component can be configured such that the covering component is a combination of an inner covering portion and an outer covering portion that overlap radially and are made of different materials. In the covering process, after the sheet forming the inner covering portion is placed on the outer periphery of the inner component and the braid, a long strip component with a radial cross-section C-shaped forming the outer covering portion is fitted onto the sheet from above, thereby covering the outer periphery of the inner component and the braid with the covering component.

[0017] In the method for manufacturing the catheter of the present invention, the covering component may be configured to include a constricting tube.

[0018] According to the above structure, the covering component is more likely to fit tightly against the outer peripheral side of the braid, thus making it easier to suppress the thickness at the front end of one yarn from increasing due to laser irradiation.

[0019] In the method for manufacturing the catheter of the present invention, the inner component is the inner layer forming the catheter.

[0020] According to the above structure, during manufacturing, the wire, which is arranged inside as a clamp, is stretched by pulling it. When the wire is pulled out of the conduit after the conduit is formed, the wire can be easily pulled out by the presence of the inner layer, so the manufacturing operation of the conduit can be easily carried out.

[0021] In the method for manufacturing the catheter of the present invention, the inner component is the shaft portion of the clamp.

[0022] Based on the above structure, since there is no need to install an inner layer for the catheter, the cost of the catheter can be reduced by reducing the number of components.

[0023] The catheter of the present invention comprises: a braid having a first thread and a second thread intersecting the first thread; and an outer layer disposed on the outer periphery of the braid, wherein the first thread and the second thread are joined radially overlapping at the intersection such that one thread is arranged radially inside the other thread, and the radially outer side of the front end portion of the first thread, which protrudes from the side of the other thread including the portion of the intersection toward the front end, is arranged at the same radial position as or radially inside the radially outer side of the other thread at the intersection.

[0024] According to the above structure, the radially outer surface of the front end of one thread is positioned at the same radially outer surface of the other thread at the intersection, or radially inner. Therefore, the thickness of the front end of one thread is less than or equal to the thickness of the intersection of the first and second threads. As a result, it is not necessary to increase the thickness of the outer layer of the guide tube to prevent the braid from protruding from the outer peripheral surface of the outer layer, and radial unevenness of the outer peripheral surface of the outer layer can be suppressed.

[0025] In the conduit of the present invention, the first wire and the second wire can be configured such that they are formed of metal wires made of the same metal material.

[0026] According to the above structure, when the first line and the second line are joined by welding, their materials melt and mix easily, thus improving the joint strength at the intersection.

[0027] In the conduit of the present invention, it is possible to configure one end of the first line to have a side protrusion extending along the length direction of the other line in a manner that separates it from the intersection.

[0028] Based on the above structure, the contact area between the ends of the braid and the inner component can be increased. Therefore, when the inner component is used as the inner layer, the ends of the braid are less likely to detach from the inner layer.

[0029] In the catheter of the present invention, the front end of the other line can be configured to have a protrusion on the other side that extends out from the intersection along the length direction of the other line.

[0030] Based on the above structure, the contact area between the ends of the braid and the inner component can be increased. Therefore, when the inner component is used as the inner layer, the ends of the braid are less likely to detach from the inner layer.

[0031] The catheter of the present invention comprises: a braid having a first thread and a second thread intersecting the first thread; and an outer layer disposed on the outer periphery of the braid, wherein the first thread and the second thread are joined radially overlapping at the intersection such that one thread is arranged radially inside the other thread, the intersection having a recess on its front end side at least on its radially outer side, and the front end of the first thread not protruding from the side of the front end side of the intersection.

[0032] According to the above structure, since the front end of one line does not protrude from the side of the other line in the width direction towards the front end, it is possible to suppress the thickness of the front end of one line from being greater than the thickness of the intersection of the first and second lines. Therefore, it is not necessary to increase the thickness of the outer layer of the guide tube to prevent the braid from protruding from the outer peripheral surface of the outer layer, and radial unevenness of the outer peripheral surface of the outer layer can be suppressed.

[0033] The effects of the invention

[0034] According to the manufacturing method and the catheter of the present invention, it is possible to suppress the increase in thickness of the front end of the braid relative to the thickness of the intersection of each thread, and to suppress radial unevenness of the outer peripheral surface of the outer layer. Attached Figure Description

[0035] Figure 1This is a diagram showing the usage state of a catheter as an example of an embodiment.

[0036] Figure 2 yes Figure 1 The diagram shows the overall structure of the catheter.

[0037] Figure 3 It is shown in Figure 2 The diagram shows a three-dimensional view of the duct after a portion of the outer layer of the distal shaft has been removed.

[0038] Figure 4 yes Figure 3 A rough AA sectional view.

[0039] Figure 5A This shows the state after the woven material is arranged on the outer periphery of the inner layer and covered from above by a covering component. Figure 4 A comparable sectional view.

[0040] Figure 5B From Figure 5A The diagram is viewed in the direction of arrow A.

[0041] Figure 6 (a) is a diagram showing the cut line when the end of the braid is cut with a laser in the catheter manufacturing method of the embodiment. Figure 6 (b) is a diagram showing the end of the braid after it has been cut in the manufacturing method of the catheter in the embodiment.

[0042] Figure 7 This diagram illustrates the cutting process of irradiating the braid with a laser to cut the first thread, the covering removal process of removing the covering component, and the thread removal process of removing the excess portion of the first thread in the manufacturing method of the catheter according to the embodiment.

[0043] Figure 8 This is an enlarged view of the end of the braided body after the process is removed, viewed from the radial outer side.

[0044] Figure 9 It is an enlarged view of the end of the braided body after the process is removed, viewed from the outside along a direction inclined relative to the radial direction.

[0045] Figure 10 yes Figure 9 CC enlarged sectional view.

[0046] Figure 11 This is a diagram showing the case where the welded portion at the end of the braid in the comparative example of the conduit becomes larger.

[0047] Figure 12 This is a diagram illustrating the coating process in a catheter manufacturing method of another embodiment.

[0048] Figure 13 This is a diagram illustrating the coating process in a catheter manufacturing method of another embodiment.

[0049] Figure 14 Is Figure 13 A radial cross-sectional view of the outer covering portion of the covering component used in the manufacturing method.

[0050] Figure 15 Another example of the implementation method is the conduit with Figure 8 The corresponding diagram.

[0051] Figure 16 It is shown Figure 15 A diagram of the outline of section D1-D2. Detailed Implementation

[0052] Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The embodiment described below is merely an example, and the present invention is not limited to the following embodiment.

[0053] use Figures 1-10 The guide extension catheter 10, which is one example of an embodiment, will be described. Figure 1 As shown, the guiding extension catheter 10 is used, for example, by inserting the outlet portion of the guiding catheter 100 into the coronary artery 102, and then extending the stent delivery catheter 106 from the distal end P of the outlet portion. Figure 1 In the diagram, the guided catheter 100 is indicated by the blackened portion. Hereinafter, the guided extension catheter 10 will be referred to as catheter 10. Because in Figure 1 The catheter 10 is used in the state shown, therefore its distal end P is required to be flexible so that it can be easily inserted into organs such as blood vessels.

[0054] Figure 2 This is an overall view of catheter 10. Catheter 10 is an elongated component, configured to include a cylindrical distal shaft 12 and a proximal shaft 50 made of metal wire connected to the proximal end of the distal shaft 12. The distal end of the proximal shaft 50 is connected to a circumferential portion of the outer peripheral surface of the distal shaft 12. In this embodiment, "proximal end side" refers to the posterior side relative to the direction in which catheter 10 is inserted into the blood vessel. Figure 2 (Right side of the catheter). Additionally, "distal end" refers to the anterior side relative to the direction in which catheter 10 is inserted into the blood vessel. Figure 2 (Left side of the middle).

[0055] Figure 3This is a perspective view showing the state after a portion of the outer layer 30 of the distal shaft 12 has been removed from the catheter 10. Figure 4 yes Figure 3 A schematic AA cross-sectional view. The distal shaft 12 includes an inner layer 14 made of resin, a braid 16 disposed on the outer periphery of the inner layer 14, and an outer layer 30 disposed on the outer periphery of the braid 16 and having resin. The inner layer 14 corresponds to the inner component and forms the conduit 10.

[0056] A lumen 15 for inserting other conduits is formed inside the inner layer 14. The resin material constituting the inner layer 14 is not particularly limited, and polytetrafluoroethylene (PTFE) is used for example. The inner layer 14 is not limited to a single-layer tube, but can also be a multi-layer tube made of the same or different materials.

[0057] The braided body 16 is formed by weaving the first thread 17 and the second thread 18 into a mesh shape. For example, multiple first threads 17 are wound around the outside of the inner layer 14 along a first direction inclined relative to the length direction of the distal axis 12. Additionally, multiple second threads 18 are wound around the outside of the inner layer 14 along a second direction intersecting the first direction, also inclined relative to the length direction of the distal axis 12. The first threads 17 and the second threads 18 are formed of metal wires made of the same metallic material, such as tungsten or stainless steel. Figure 4 The cross-section of the braided body 16 is schematically shown through multiple rectangular sections. The radial cross-sections of the first thread 17 and the second thread 18, each orthogonal to the length direction, are rectangular, but the radial cross-sections of one or both of the first thread 17 and the second thread 18 can also be circular. Figure 4 In the diagram, the overlapping portion of the first thread 17 and the second thread 18 at the intersection is shown as the braid 16.

[0058] The outer layer 30 covers the outer periphery of the inner layer 14 and the braid 16. Thus, the outer layer 30 is disposed on the outer periphery of the braid 16. The resin material constituting the outer layer 30 is not particularly limited, and can be formed, for example, from polyether block amide (PEBA), polyethylene (PE), polypropylene (PP), polyamide (PA), polyimide (PI), polyamide-imide (PAI), polyethylene terephthalate (PET), polyurethane (PU), nylon elastomer, polyester elastomer, ethylene-vinyl acetate resin (EVA), polyvinyl chloride (PVC), etc. For example, Pebax (registered trademark) manufactured by Arkema Corporation can also be used as the resin constituting the outer layer 30. A hydrophilic coating such as hyaluronic acid, polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), polyvinyl alkyl ether, and maleic anhydride copolymer (VEMA) is preferably applied to the outer peripheral surface of the outer layer 30. For example, a hydrophilic coating may be applied only to a portion from the distal end P of the outer layer 30 to a predetermined position in the length direction. The outer layer 30 is not limited to a single-layer tube; it can also be a multi-layer tube made of the same or different materials. Furthermore, the hardness of different portions of the outer layer 30 along its length can vary. For example, when the outer layer 30 is divided into a distal end, a middle portion, and a proximal end, the resin forming the distal end can have the lowest hardness, the resin forming the proximal end can have the highest hardness, and the resin forming the middle portion can have a hardness intermediate between the resins forming the distal and proximal ends.

[0059] Furthermore, a front tip 31 is provided at the distal end of the distal shaft 12. Figure 2 The tip 31 is formed from a portion of the outer layer and contains metal powder that does not allow X-rays to pass through, mixed into the resin. Figure 2 The tip 31 is shown in the diagram using the sand-like part at the front end of the distal shaft 12. For example, bismuth oxide (Bi), tungsten (W), barium sulfate, etc., are used as metal powders. In this way, by incorporating metal powders that do not allow X-rays to pass through into the resin of the outer layer 30 to form the tip 31, the flexibility of the front end of the distal shaft 12 is ensured, and the distal end position of the distal shaft 12 can be easily identified by the surgeon under X-ray fluoroscopy.

[0060] Furthermore, by not positioning the braid 16 within the range from the distal end of the distal shaft 12 to a predetermined length, the distal end of the distal shaft 12 is made more flexible, making it easier to insert the catheter 10 into tubular organs such as blood vessels. To form the braid 16 in this manner, excess portions of the front end of the braid 16 located on the distal end side of the distal shaft 12 are cut off and removed by laser irradiation. Then, the front ends of the first thread 17 and the second thread 18 at the cut portion are welded together, preventing the braid 16 from unraveling from the cut portion. The following description focuses on the front end of the braid 16 located on the distal end side of the distal shaft 12.

[0061] In the braid 16, at the front end located on the distal end side of the distal shaft 12, the first thread 17 and the second thread 18 overlap radially at the intersection 19 in such a way that one thread is arranged radially inside the other thread, and are joined by welding, the front end 22 of one thread ( Figure 7 It protrudes towards the front end from the side of the portion of the other line that includes the intersection. Furthermore, the radially outer side surface 22a of the front end portion 22 of one line... Figure 7 The outer layer 30 is positioned at the same radial position as the outer radial side of the other thread at the intersection 19, or radially inside it. This prevents the thickness of the front end 22 of one thread from exceeding the thickness of the intersection 19. Therefore, it is not necessary to increase the thickness of the outer layer 30 to prevent the braid 16 from protruding from the outer peripheral surface of the outer layer 30, and radial unevenness on the outer peripheral surface of the outer layer 30 can be suppressed.

[0062] Furthermore, since the first wire 17 and the second wire 18 are formed from metal wires of the same metallic material, when the first wire and the second wire are joined by welding as in this example, their materials melt and mix easily. As a result, the joint strength at the intersection 19 of the first wire 17 and the second wire 18 can be improved.

[0063] In addition, as will be discussed later Figure 8 , Figure 9 As shown, the front end 22 of one yarn has a side protrusion 23 extending away from the intersection along the length direction of the other yarn. This increases the contact area between the end of the braid 16 and the inner layer 14, making it less likely for the end of the braid 16 to detach from the inner layer 14.

[0064] Next, use Figures 5A to 10The manufacturing method of the conduit 10 will be described. First, a "configuration process" is performed in which the braid 16 is disposed on the outer peripheral surface of the inner layer 14, i.e., the cylindrical outer peripheral surface. At this time, the inner layer 14 can be extruded into a long cylindrical strip using an extruder or the like for resin materials, either on a metal core wire or on a shaft formed in a clamp. A braiding machine can also be used to configure the braid 16 on the outer periphery of the inner layer 14. The braiding machine winds a plurality of first threads 17 around the cylindrical outer peripheral surface of the inner layer 14 in a first direction inclined relative to the length direction of the inner layer 14, and winds a plurality of second threads 18 around the cylindrical outer peripheral surface of the inner layer 14 in a second direction inclined relative to the length direction of the inner layer 14 and intersecting the first direction. At this time, the braid 16 is configured to extend to approximately the front end of the inner layer 14.

[0065] Next, the "coating process" is carried out. In the coating process, such as... Figure 5A , Figure 5B As shown, in the intermediate component 20 (composed of inner layer 14 and braided body 16) Figure 5A On the outer periphery of the braided body 16, a transparent or semi-transparent covering component 34 that allows laser light to pass through is used. For example, a transparent shrink tube is used as the covering component 34. The shrink tube has the function of shrinking in diameter by heating. The shrink tube is formed, for example, from a resin material such as FEP (a fluoropolymer of tetrafluoroethylene and hexafluoropropylene). With the shrink tube covering the outer periphery of the intermediate component 20, it is heated to the shrinkage temperature of the shrink tube by a heater or high-frequency electromagnetic waves, and then pressed against the outer periphery of the braided body 16. Figure 5A The figure shows the covering component 34 closely attached to the outer peripheral surface of the inner layer 14, but the covering component 34 can also be set to be roughly cylindrical only closely attached to the outermost peripheral surface of the braid 16.

[0066] Next, the "cutting process" is carried out. Figure 6 (a) is a diagram showing the cut line when the end of the braid 16 is cut with a laser. Figure 6 (b) is a diagram showing the cut end of the braid 16. Figure 6 In the middle, laser light is irradiated onto line 17 at the black dotted areas, and onto line 28 at the black corners. Figure 6The illustration of the covering component 34 is omitted. When laser light is irradiated onto the black dots and black corners, the laser-irradiated portions of the first line 17 and the second line 18 melt, and each line 17 and 18 is cut through this melting. Simultaneously with the cutting of each line 17 and 18, the molten portion of the line extending from the intersection 19 on the inner circumference side of the two lines 17 and 18 approaches the intersection 19 and solidifies, thereby joining the first line 17 and the second line 18. The solidified portion forms the front end 22 of the line protruding from the intersection 19 towards the front end side, located on the inner circumference side. Furthermore, the molten portion of the line extending from the intersection 19 on the outer circumference side of the intersection 19 may also approach the intersection 19 and solidify, but... Figure 6 The illustration of the leading edge of the line arranged on the outer periphery, formed by the solidified portion of the molten part, is omitted in (b).

[0067] More specifically, a laser is used to irradiate a portion of at least one of the first thread 17 and the second thread 18 of the braid 16, which is closer to the front end than the cross portion 19, from the outside of the covering member 34. Then, one thread is cut, and the first thread 17 and the second thread 18 are welded together.

[0068] Figure 7 The diagram shows a cutting process (a) and (b) in which the first thread 17 of the braid 16 is cut by irradiating the first thread 17 with a laser 60, a covering removal process (c) in which the covering member 34 is removed, and a thread removal process (d) in which the excess portion of the first thread 17 is removed.

[0069] like Figure 7 As shown in (a), the laser 60 passes through the covering member 34 and irradiates the portion of the first line 17 that is closer to the front end than the intersection 19 of the first line 17 and the second line 18. At this time, the first line 17 passes through the inner periphery of the second line 18 in the intersection 19. Furthermore, a portion of the laser 60 also irradiates the second line 18 in the intersection 19.

[0070] Through laser irradiation, such as Figure 7 As shown in (b), the portion of the first line 17 located at the intersection 19, passing through the inner circumference of the second line 18 and situated on the front end side of the second line 18, is cut off between this portion and a portion further towards the front end. Simultaneously, the portion of the first line 17 that has molten deforms in a manner approaching the intersection 19, increasing its radial thickness and forming a front end portion 22 of the first line 17 protruding from the intersection 19 towards the front end side. The front end portion 22 of the first line 17 is joined to the portion of the second line 18 located at the intersection 19 by welding. Figure 7In (b), the front end portion 22 of the first thread 17 is shown with sand dots. It is also possible that at the front end portion 22 of the first thread 17, the molten portion of the second thread 18 mixes with the molten portion of the first thread 17 and solidifies. In this specification, regarding each thread joined at the crossover 19, the portion located on the extension line of each thread, closer to the front end of the crossover 19, is referred to as the front end portion of the thread, regardless of whether the molten portions of the threads are mixed. Furthermore, the outer periphery of the braid 16 is pressed by the covering member 34.

[0071] And, although in Figure 7 Not shown in the diagram, but during the cutting process, a laser is irradiated onto the second thread 18 of the braided body 16, which extends from the intersection of the second thread 18 and the inner periphery of the first thread 17 towards the front end, cutting the second thread 18, and then welding the first thread 17 and the second thread 18 together. In this case, with... Figure 7 The first thread 17 and the second thread 18 are made to be in opposite states. At this time, the laser 60 shines through the covering member 34 onto the front end of the second thread 18, onto the portion closer to the front end of the intersection of the first thread 17 and the second thread 18. A portion of the laser 60 also shines onto the first thread 17 at the intersection. Thus, in the cutting process, the laser 60 shines from the outside of the covering member 34 onto the portion closer to the front end of one of the first thread 17 and the second thread 18 of the braid 16, and onto the other thread, cutting one thread and welding the first thread 17 and the second thread 18. Alternatively, when shining the laser on the portion closer to the front end of one of the first thread 17 and the second thread 18, the laser may not shine on the other thread, and the first thread 17 and the second thread 18 may be welded at the same time as cutting one thread.

[0072] Next, as Figure 7 As shown in (c), a covering removal process is performed to remove the covering member 34 from the outer periphery of the braid 16 and the inner layer 14. After that, a thread removal process is performed to remove the remaining portion 21 that has been cut off from the braid 16 at the cut portion of the first thread 17. Figure 7 (d)

[0073] Figure 8 This is an enlarged view of the end of the braided body 16 after the removal of the radial lines, viewed from the radial outer side. Figure 9 This is an enlarged view of the end of the braided body 16 after the removal process, viewed from the outside along a direction inclined relative to the radial direction. Figure 10 yes Figure 9 A CC-enlarged sectional view. For example... Figures 8-10As shown, in the state after the online removal process, a front end portion 22 of the first thread 17 protruding from the front end side of the second thread 18 is formed at the end of the braid 16. Furthermore, the first thread 17 and the second thread 18 are joined at multiple intersections 19 via the front end portion 22 of the first thread 17. At this time, as described above, during the cutting process, the outer periphery of the braid 16 is covered by the covering member 34, and therefore the radially outer surface 22a of the front end portion 22 of the first thread is also pressed by the covering member 34. Thus, the radially outer surface 22a of the front end portion 22 of the first thread 17 (one thread) is positioned at the intersection 19 with the radially outer surface 18a of the second thread 18 (the other thread). Figure 10 In the radial direction ( Figure 10 The same position in the vertical direction or the inner side of the radial direction ( Figure 10 (The lower side). Furthermore, the radially outer surface 22a of the front end portion 22 of the first line becomes a flat surface. Additionally, although in Figures 8-10 The illustration is omitted, but in the state after the online removal process, the end of the braid 16 also has a front end of the second line 18 located on the inner periphery that protrudes from the side of the front end of the first line 17 located on the outer periphery, in the same way as the front end 22 of the first line 17 that protrudes from the side of the front end of the second line 18.

[0074] Furthermore, such as Figure 8 , Figure 9 As shown, the front end 22 of one line (first line 17) on the inner periphery has a side protrusion 23 extending away from the intersection 19 along the length direction of the other line (second line 18) on the outer periphery. Figure 8 , Figure 9 The protruding portion 23 on one side is shown in an exaggerated manner. The reason for forming the protruding portion 23 in this way can be considered as follows: when the braid 16 is irradiated with laser 60, the outer periphery of the braid 16 is covered by the covering member 34, and the radially outer surface 22a of the leading end 22 of one thread is pressed by the covering member 34. When the leading end of the first thread 17, which has melted due to laser irradiation, approaches the intersection 19, the portion that does not escape radially outward extends in a circumferential manner. Figure 8 In the example, on the other thread (second thread 18), adjacent to the intersection 19, a protrusion 24 is formed extending from the intersection 19 toward the length of the other thread. The protrusion 23 on one side and the protrusion 24 on the other side increase the contact area between the end of the knitted body 16 and the inner layer 14. Therefore, the end of the knitted body 16 is less likely to detach from the inner layer 14.

[0075] exist Figure 7After the (d) line removal process, a resin-made outer layer 30 is formed on the outer periphery of the intermediate component 20 to form the distal shaft 12. Then, the conduit 10 is formed by combining the proximal shaft 50 with the distal shaft 12.

[0076] According to the above-described method for manufacturing the conduit 10, it is possible to suppress the increase in thickness at the tip of one of the wires due to laser irradiation 60 during cutting. Furthermore, before laser irradiation-based cutting of the first wire 17 and the second wire 18, it is not necessary to pre-join the first wire 17 and the second wire 18 at the intersection 19 by laser irradiation. As a result, the number of laser irradiations can be reduced.

[0077] Furthermore, during the cutting process, laser 60 is applied from the outside of the covering member 34 to the portion of one of the first thread 17 and the second thread 18 of the braid 16 that is closer to the front end of the intersection 19, and to the other thread, cutting one thread and welding the first thread 17 and the second thread 18. Thus, after the first thread 17 and the second thread 18 have melted, the solidified portion further enhances the bonding strength between them. Moreover, when a shrink tube is used as the covering member 34, it is easier for the covering member 34 to adhere tightly to the outer peripheral end of the braid 16, thus more easily suppressing the increase in thickness at the front end of one thread due to laser irradiation. Furthermore, since the inner member disposed on the inner peripheral side of the braid 16 serves as the inner layer 14 forming the guide tube 10, during manufacturing, the wire disposed on the inner side as a clamp is stretched, and when the wire is pulled out of the guide tube 10 after its formation, the presence of the inner layer 14 facilitates easy removal of the wire. Therefore, the manufacturing of the catheter 10 can be carried out easily.

[0078] Furthermore, according to the aforementioned conduit 10, in the braid 16, the first thread 17 and the second thread 18 are joined radially overlapping at the intersection 19, with one thread positioned radially inside the other. The radially outer side 22a of the front end portion 22 of the first thread, which protrudes from the side of the portion of the other thread including the intersection in the width direction towards the front end, is positioned at the same radially outer side as or radially inside the radial side of the other thread at the intersection 19. Thus, the thickness of the front end portion of the first thread is less than or equal to the thickness of the intersection 19. Therefore, it is not necessary to increase the thickness of the outer layer 30 of the conduit 10 to prevent the braid 16 from protruding from the outer peripheral surface of the outer layer 30, and radial unevenness of the outer peripheral surface of the outer layer 30 can be suppressed. Additionally, in the above description, the case where the thickness of the front end portion 22 of the first thread positioned radially inside the intersection 19 is less than or equal to the thickness of the intersection 19 has been explained. On the other hand, in the intersection 19, the thickness of the front end of the other line that protrudes from the intersection 19 and is disposed on the outer side is also less than the thickness of the intersection 19, and the outer side of the front end of the other line is disposed at the same position in the radial direction as the outer side of the other line at the intersection 19 or on the inner side in the radial direction.

[0079] Figure 11 This illustrates a case where the welded portion at the front end of the braid 16a in the comparative example catheter is enlarged. In the comparative example catheter, compared to... Figures 1-10 The structure shown differs in that, when laser irradiation is applied to the braid 16a to cut the first thread 17 and the second thread 18, and when the first thread 17 and the second thread 18 are welded together, the inner layer 14 and the outer periphery of the braid 16a are not pre-covered with a covering component. Figure 11 The diagram illustrates the following: Joints 40a and 40b are formed on the front end side of the second line 18, extending from the inner circumference of the first line 17 through the second line 18. These joints 40a and 40b have bulges that extend radially outward due to laser irradiation. The first line 17 and the second line 18 are welded at these joints 40a and 40b. During the welding of the first line 17 and the second line 18, the joints 40a and 40b bulge radially outward without being restrained by the covering component on their radially outer sides. Furthermore, in… Figure 11In this state, the outermost circumferential surfaces of the joints 40a and 40b, excluding the front ends of the first thread 17 and the second thread 18 of the braid 16a, protrude radially outward, and the radially outer end of the joint 40a is further outward by a radial dimension d (e.g., tens of μm) compared to the aforementioned outermost circumferential surface. In this comparative example of the conduit, the thickness of the joints 40a and 40b, which are the front ends of the first thread 17 and the second thread 18, is greater than the thickness of the intersection adjacent to the joint. Therefore, it is necessary to increase the thickness of the outer layer covering the outer periphery of the braid 16 to prevent the braid 16a from protruding from the outer periphery of the outer layer, and the radial position of the outer periphery of the outer layer may change locally, making the outer periphery of the outer layer radially uneven. Figures 1-10 The implementation shown can prevent such adverse conditions.

[0080] Figure 12 This diagram illustrates the coating process in a method for manufacturing a conduit, representing another embodiment. In the coating process of this example's manufacturing method, a thin sheet 35 of silicone rubber (e.g., approximately 100 μm thick) is used instead of a shrink tubing as the coating component. The sheet 35 is translucent and lacks adhesive strength. In the coating process, the width direction of the sheet 35 (… Figure 14 The middle part of the intermediate component 20, which is composed of an inner layer 14 and a braided body 16, is placed in the left-right direction. Figure 3 The outer periphery of the pre-welded portion of the sheet 35 is then placed. Next, block-shaped magnets 36 are respectively disposed on the upper sides of both ends of the sheet 35 in the width direction. The two ends of the sheet 35 are fixed to the plate 37 using the magnetic force acting between the magnet and the upper surface of a plate 37 made of a magnetic material such as an iron plate disposed on the upper surface of the fixing table. The welding process is performed in this state. For example, in the cutting process, while the intermediate part 20 is rotated little by little, a laser is irradiated from the upper side of the intermediate part 20 towards the vicinity of the pre-cut portion. In the manufacturing method of this example, other structures are similar to... Figures 1-10 The structures are the same.

[0081] Figure 13 This is a diagram illustrating the coating process in a catheter manufacturing method of another embodiment. Figure 14 It is shown in Figure 13 A cross-sectional view of the outer covering portion 43 of the covering member 41 used in the manufacturing method. In the manufacturing method of this example, the covering member 41 uses a combination of an inner covering portion 42 and an outer covering portion 43, which coincide radially and are made of different materials. The outer covering portion 43 is located on the outer periphery of the inner covering portion 42. The inner covering portion 42 is, for example, made of... Figure 12The sheet 35 shown is formed from a thin sheet of silicone rubber of the same thickness. The outer covering 43 is, for example, a long strip member with a C-shaped radial cross-section. The outer covering 43 is formed, for example, by removing a circumferential portion of the heat-shrinkable shrink tube along its entire length after it has been fitted into the axial member of the long strip.

[0082] In the covering process, the covering component 41 covers the woven fabric 16. Figure 3 The outer periphery of the ) . In the coating process, such as Figure 13 As shown in (a), an intermediate member 20, whose length end is gripped by a clamp (not shown), is disposed on the upper surface of a plate 37 made of a magnetic material such as an iron plate placed on a fixed platform. Next, as... Figure 13 As shown in (b), in the intermediate component 20, the inner covering portion 42 is placed on the outer periphery of the portion containing the welding pre-determined portion of the braid 16 in the longitudinal direction. Figure 13 The middle part of (b) and (c) in the vertical direction. Then, as... Figure 13 As shown in (c), in the intermediate member 20, the outer covering portion 43 is fitted into the portion containing the inner covering portion 42 from above the inner covering portion 42. Thus, the inner layer 14 can be covered by the covering member 41. Figure 3 The outer periphery of the braid 16 is pressed with the covering member 41. The cutting process is performed in the following state: using, for example... Figure 12 The magnetic force of the magnet 36 shown fixes the two ends of the inner covering portion 42 extending from the outer covering portion 43 in the longitudinal direction to the plate 37. In the manufacturing method of this example, other structures are similar to... Figures 1-10 structure or Figure 12 The structures are the same.

[0083] Figure 15 Another example of the implementation method is the conduit with Figure 8 The corresponding diagram. Figure 16 It is shown Figure 15 A diagram showing the outline of the D1-D2 section. In this example, the conduit is similar to those described above; in the braided body 16, the first thread 17 and the second thread 18 are joined radially overlapping at the intersection 19, with one thread positioned radially inside the other. Furthermore, a recess 19b is provided at least on the front end side of the radially outer side 18a of the intersection 19, and the front end of one thread does not protrude from the width direction side 19a of the front end side of the intersection 19 (the width direction side of the other thread including the portion of the intersection 19). Additionally, as... Figure 16 As shown, the maximum thickness Lmax of the intersection 19 of line 17 and line 18 is equal to the thickness L of line 17 and line 18 respectively. 17 L 18 The sum of (L) 17+L 18 However, in the portion including the recess 19b, the thickness of the cross portion 19 gradually decreases towards the width direction of the side 19a on the front end side.

[0084] The manufacturing method of the conduit having such a recess 19b is the same as the examples described above, involving the process of placing the braided body 16 on the cylindrical outer peripheral surface 14a of the inner layer 14 and using the covering member 34 ( Figure 5A After the covering process of the inner layer 14 and the outer periphery of the braid 16, a cutting process is performed. In the cutting process, a laser is irradiated from the outside of the covering member 34 onto the following portions of the braid 16: the portion of one of the first threads 17 and the second thread 18 located on the inner periphery of the intersection 19, closer to the front end of the intersection 19; and the front end of the radially outer surface of the other thread located on the outer periphery of the intersection 19. Then, one thread is cut, and the first thread 17 and the second thread 18 are welded. At this time, the laser irradiation position and energy are adjusted so that the laser energy melts and cuts the portion of one thread closer to the front end of the intersection 19, and also melts the front end of the radially outer surface 18a of the intersection 19 to form a recess 19b. At this time, as... Figure 15 As shown, a laser can also be irradiated onto the other line, causing a recess 19b to be formed not only at the intersection 19 but also on a continuous portion along the axial central side from the intersection 19 toward the length of the other line. After the cutting process, similar to the examples described above, a covering removal process to remove the covering member 34 and a line removal process to remove excess portions of the first line 17 are performed. Figure 15 The image shows the joint where the first line 17 is disposed at the intersection 19 on the inner periphery side of the second line 18, but the joint where the second line 18 is disposed at the intersection on the inner periphery side of the first line 17 is also formed in the same way.

[0085] According to the conduit in this example, it is possible to prevent the formation of a thicker front end of the side 19a of the conduit from the width direction of the other side of the outer peripheral side towards the front end side at the intersection 19. Therefore, it is not necessary to increase the thickness of the outer layer of the conduit to prevent the braid 16 from protruding from the outer peripheral surface of the outer layer, and it is possible to suppress radial unevenness on the outer peripheral surface of the outer layer 30. In this example, other structures and functions are the same as those in the example. Figures 1 to 11 The structure is the same. Furthermore, in this example, the recess 19b can also be formed to reach the inner circumferential side of the intersection. Alternatively, it can be configured such that a portion of the braided structure of the conduit... Figure 8 As shown, the front end 22 of a square line forms from the side of the intersection 19, and in other parts such as Figure 15 As shown, a recess 19b is formed on the side of the intersection 19.

[0086] In the examples described above, structures other than shrink tubes, or combinations of inner and outer coverings, can be used as the covering component. For instance, transparent or semi-transparent tape or semi-transparent low-adhesion tape can be wrapped around the outer periphery of the intermediate component to make it adhere tightly to the outer periphery of the braid 16. Alternatively, a cylindrical component made of glass or a long strip component with an arc-shaped cross-section can be used as the covering component.

[0087] Furthermore, in the examples described above, the conduit 10 was described as having an inner layer 14 on the inner circumferential side of the braid 16, but the conduit can also be configured without an inner layer. In this case, the necessary portions of the braid are cut and welded by laser irradiation while the braid is wound around the shaft portion formed on the clamp. At this time, the shaft portion of the clamp acts as the inner component. In addition, after cutting and welding, to facilitate the removal of the braid from the clamp, a resin coating as a lubricating material is applied to the shaft portion of the clamp before winding the braid. After the braid is formed, an outer layer is formed on the outer circumferential side of the braid. In this structure, since it is not necessary to provide an inner layer for the conduit, the cost of the conduit can be reduced by reducing the number of components.

[0088] Furthermore, in the structures described above, the case where one of the first and second wires is cut by laser irradiation during the cutting process of the conduit manufacturing method, and the first and second wires are then welded together, has been explained. However, it is also possible to cut one of the first and second wires by laser irradiation during the cutting process, and then perform the welding process of welding the first and second wires separately from the cutting process. Additionally, in the structures described above, the case where the first wire 17 and the second wire 18 are formed of metal wires of the same metallic material has been explained. However, the first wire 17 and the second wire 18 can also be formed of different metallic materials.

[0089] Furthermore, in the above description, at the front end of the braid 16 located at the distal end of the distal shaft 12, the excess portion is cut off by laser irradiation, and then the front ends of the first thread 17 and the second thread 18 at the cut portion are welded together, thereby preventing the braid 16 from unraveling from the cut portion. Alternatively, the structure of the present invention can also be configured such that at the front end of the braid 16 located at the distal end of the distal shaft 12, the excess portion is removed, and the front ends of the first thread 17 and the second thread 18 at the cut portion are welded together, thereby preventing the braid 16 from unraveling from the cut portion. Additionally, in the examples described above, the catheter manufactured by the manufacturing method of the present invention is a guide extension catheter; however, the catheter manufactured by the manufacturing method of the present invention is not limited to this, and can be any type of catheter with braids on the inner side of the outer layer.

[0090] Label Explanation

[0091] 10: Guiding extension catheter (catheter); 12: Distal axis; 14: Inner layer; 14a: Cylindrical outer peripheral surface; 15: Lumen; 16, 16a: Braid; 17: First line; 18: Second line; 18a: Radial lateral surface; 19: Cross section; 19a: Width direction side; 19b: Recess; 20: Intermediate component; 21: Remaining portion; 22: Anterior end of one line; 22a: Radial lateral surface; 23: One side extension; 24: The other side extension; 30: Outer layer; 31: Anterior tip; 34: Covering component; 35: Sheet; 36: Magnet; 37: Plate; 40a, 40b: Joint; 41: Covering component; 42: Medial cover; 43: Lateral cover; 50: Proximal axis; 60: Laser; 100: Guiding catheter; 102: Coronary artery; 106: Stent delivery catheter.

Claims

1. A method for manufacturing a catheter, the catheter comprising: a braid having a first thread and a second thread intersecting the first thread; and an outer layer disposed on the outer periphery of the braid. The method for manufacturing the catheter includes: In the configuration process, the braided body is configured on the cylindrical outer circumferential surface of the inner component; In the coating process, the outer periphery of the woven body is coated with a coating component that allows laser light to pass through; The cutting process involves irradiating a portion of at least one of the first and second threads in the braid from the outside of the covering component with a laser to cut the first thread near the front end of the crossover point; and The removal process involves removing the covering component from the outer periphery of the woven body.

2. The method for manufacturing a catheter according to claim 1, wherein, In the cutting process, a laser is irradiated from the outside of the covering component onto the portion of at least one of the first and second threads in the braid that is closer to the front end of the intersection to cut the first thread, and the first and second threads are then welded together.

3. The method for manufacturing a catheter according to claim 1, wherein, In the cutting process, a laser is irradiated from the outside of the covering component onto the portion of one of the threads in the braid that is closer to the front end of the cross section and the other thread of the first thread and the second thread to cut the one of the threads and weld the first thread and the second thread.

4. The method for manufacturing a catheter according to any one of claims 1 to 3, wherein, The covering component is a combination of an inner covering part and an outer covering part that overlap radially and are made of different materials. In the covering process, after the sheet forming the inner covering portion is placed on the outer periphery of the inner component and the braid, a long strip member with a radial cross-section of C-shape forming the outer covering portion is fitted onto the sheet from above, thereby covering the outer periphery of the inner component and the braid with the covering member.

5. The method for manufacturing a catheter according to any one of claims 1 to 3, wherein, The covering component includes a shrink tube.

6. The method for manufacturing a catheter according to any one of claims 1 to 3, wherein, The inner component is the inner layer that forms the conduit.

7. The method for manufacturing a catheter according to any one of claims 1 to 3, wherein, The inner component is the shaft of the clamp.

8. A catheter comprising: A braided body having a first thread and a second thread intersecting the first thread; and The outer layer is disposed on the outer periphery of the woven body. In the braid, the first thread and the second thread are joined radially overlapping at the intersection in such a way that one thread is arranged radially inside the other thread, the intersection having a recess on the front end side of at least its radially outer side, and the front end of the first thread not protruding from the side of the front end side of the intersection.

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