Catheter manufacturing method

Abstract

To provide a manufacturing method of a catheter that can easily insert a conductor wire into a lumen of a shaft and improve production efficiency.SOLUTION: A manufacturing method of a catheter includes the steps of: arranging a distal part of a conductor wire insertion tool 30 in a lumen of a distal part of a shaft; inserting a conductor wire into a side hole in a direction from the outside of the shaft toward the lumen of the shaft; arranging an end of the conductor wire to a distal side than the side hole and a proximal side than a distal end of the shaft; and removing the conductor wire insertion tool from a proximal end of the shaft to expose the conductor wire from the proximal end of the shaft. The conductor wire insertion tool includes: three or more wires 31; a distal end fixing part 32 at which multiple wires are fixed one another at distal ends 31d of the wires; and a proximal side fixing part 33 at which multiple wires are fixed one another at proximal ends 31p of the wires. The conductor wire insertion tool includes multiple closed loops 34 formed by one wire 31A and another wire 31B, and the multiple closed loops are not on the same plane.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a catheter having a conducting wire in the lumen of a shaft.

Background Art

[0002] In inspections and treatments, a catheter having an electrode connected to a conducting wire may be used. Specifically, during an inspection of an arrhythmia such as atrial fibrillation, a catheter having an electrode is inserted into the heart cavity, and the intracardiac potential is measured to identify an abnormal site in the heart that is causing the arrhythmia. During the treatment of an arrhythmia, a high-frequency current is passed from the electrode of the catheter to the myocardium that is causing the arrhythmia, and the origin of the arrhythmia is electrically separated from the heart by ablation. Further, when atrial fibrillation naturally occurs during these inspections or treatments, or when atrial fibrillation is induced for identifying an abnormal part of the heart, defibrillation is performed by applying an electrical stimulus from the electrode of the catheter to the heart. In addition to the electrode, a catheter in which a sensor such as a temperature sensor or a pressure sensor is connected to a conducting wire may also be used.

[0003] For example, Patent Document 1 describes a method for manufacturing a catheter having an electrode connected to a conducting wire, including a step of bending a shaft having a distal side, a proximal side, and a lumen, and having a first hole and a second hole through which the lumen communicates with the outside; a step of inserting a first conducting wire into the lumen of the shaft from the first hole and exposing the first conducting wire from the proximal end of the shaft; a step of moving the first conducting wire closer to the inside of the bend of the shaft after the bending step; and a step of inserting a second conducting wire into the lumen of the shaft from the second hole and exposing the second conducting wire from the proximal end of the shaft, wherein the step of inserting the second conducting wire is performed after the step of moving the first conducting wire closer to the inside of the bend of the shaft.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

[0005] In catheters with electrodes, multiple wires are typically arranged within the lumen of the shaft, corresponding to the electrodes. Furthermore, there is a demand for smaller diameter catheter shafts to improve minimally invasiveness. In catheter manufacturing, there was room for improvement in the process of inserting multiple wires into the lumen of a small-diameter shaft, specifically in facilitating wire insertion and improving catheter productivity.

[0006] The present invention has been made in view of the above circumstances, and its purpose is to provide a method for manufacturing a catheter that makes it easier to insert a wire into the lumen of the shaft and improves production efficiency. [Means for solving the problem]

[0007] The method for manufacturing a catheter according to an embodiment of the present invention that has been able to solve the aforementioned problems is as follows. [1] A method for manufacturing a catheter comprising a shaft having a lumen extending in the longitudinal direction and having side holes in its circumferential wall, and a conductor inserted into the lumen of the shaft, The process involves placing the distal end of the wire insertion device into the lumen of the distal end of the shaft, A step of inserting the conductor into the side hole from the outside of the shaft toward the inner lumen of the shaft, The steps include positioning the end of the conductor distal to the side hole and proximal to the distal end of the shaft, The process includes removing the wire insertion tool from the proximal end of the shaft and exposing the wire from the proximal end of the shaft, The wire insertion device comprises three or more wires, a distal fixing portion at the distal end of each wire to which multiple wires are fixed to each other, and a proximal fixing portion at the proximal end of each wire to which multiple wires are fixed to each other. The wire insertion device has multiple closed loops formed by one wire and another wire different from the first wire. A method for manufacturing a catheter in which the multiple closed loops are not on the same plane. [2] The wire insertion device has a distal cylindrical member in the distal fixing portion and a proximal cylindrical member in the proximal fixing portion, Multiple wires are arranged in the lumen of the distal cylindrical member. A method for manufacturing a catheter according to [1], wherein a plurality of the wires are arranged in the lumen of the proximal cylindrical member. [3] The wire insertion device comprises a first wire and a second wire adjacent to the first wire, A method for manufacturing a catheter according to [1] or [2], wherein, in a cross section perpendicular to the longitudinal axis of the wire at the midpoint of the length of the wire in the longitudinal axis direction, the angle formed by a straight line connecting the centers of the inscribed circles of the plurality of wires and the center of the outer shape of the first wire, and a straight line connecting the centers of the inscribed circles of the plurality of wires and the center of the outer shape of the second wire, is 30 degrees or more and 120 degrees or less. [4] The wire is in a corrugated shape. A method for manufacturing a catheter according to any one of [1] to [3]. [5] The shaft has a first side hole located at the distal end and a second side hole located at the proximal end in the longitudinal direction of the shaft. A method for manufacturing a catheter according to any one of [1] to [4], wherein the length from the distal end to the proximal end of the wire in the longitudinal axis direction of the wire insertion device is longer than the length from the first side hole to the second side hole of the shaft. [Effects of the Invention]

[0008] In conventional manufacturing methods, the process of inserting the conductor into the lumen of the shaft tended to be difficult. Therefore, it was common practice to insert the conductor into the lumen of the shaft through a side hole, expose it from the tip of the shaft, pass it through a conductor insertion tool, and then insert the conductor insertion tool into the lumen of the shaft to insert the conductor into the lumen of the shaft. According to the catheter manufacturing method of the present invention, the conductor insertion tool has three or more wires, a distal fixing part at the distal end of the wires where multiple wires are fixed to each other, and a proximal fixing part at the proximal end of the wires where multiple wires are fixed to each other. The conductor insertion tool has multiple closed loops formed by one wire and other wires different from the one wire, and because the multiple closed loops are not on the same plane, it is easier for the conductor to enter the closed loops of the conductor insertion tool. Therefore, even within the lumen of the shaft, the conductor is more likely to catch on the conductor insertion tool, making the process of inserting the conductor into the lumen of the shaft easier and improving the production efficiency of catheters. [Brief explanation of the drawing]

[0009] [Figure 1] This shows an enlarged plan view of the distal portion of a wire insertion device according to one embodiment of the present invention. [Figure 2] Figure 1 shows a cross-sectional view of the wire insertion device at line II-II. [Figure 3] This diagram shows a schematic cross-sectional view of the process of placing a wire insertion device in the lumen of a shaft according to one embodiment of the present invention. [Figure 4] This diagram shows a schematic cross-sectional view of the step of inserting a conductor into a side hole in one embodiment of the present invention. [Figure 5] This diagram shows a schematic cross-sectional view of the process of arranging the conductors in one embodiment of the present invention. [Figure 6] This diagram shows a schematic cross-sectional view of the process of exposing the conductor wire from the proximal end of the shaft in one embodiment of the present invention. [Modes for carrying out the invention]

[0010] Hereinafter, the present invention will be described more specifically based on the following embodiments. However, the present invention is not limited by the following embodiments, and it is of course possible to appropriately modify and implement it within the scope that can conform to the gist of the foregoing and following descriptions, and all of them are included in the technical scope of the present invention. In each drawing, for the sake of convenience, hatching, member numbers, etc. may be omitted, but in such cases, reference shall be made to the specification and other drawings. Also, the dimensions of various members in the drawings may be different from the actual dimensions because priority is given to facilitating the understanding of the features of the present invention.

[0011] FIG. 1 is an enlarged plan view of the distal portion of the wire inserter 30 in one embodiment of the present invention, and FIG. 2 is a cross-sectional view of the wire inserter 30. That is, FIG. 2 is a cross-sectional view of the wire inserter 30 perpendicular to the longitudinal axis of the wire 31 at the midpoint P1 of the length of the wire 31 in the longitudinal axis direction of the wire 31. FIGS. 3 to 6 are schematic cross-sectional views of each step in the manufacturing method of the catheter 1 in one embodiment of the present invention.

[0012] In the present invention, the proximal side refers to the side closer to the user's hand with respect to the extending direction of the shaft 10, and the distal side refers to the opposite side of the proximal side, that is, the treatment target side. Also, the extending direction of the shaft 10 is referred to as the longitudinal axis direction. In FIGS. 1 to 6, the right side of the figure is the proximal side, and the left side of the figure is the distal side.

[0013] [[ID=1该导管1包括具有在其周壁上具有侧孔11的内腔的轴10和插入轴10的内腔中的导线20。

[0014] An electrode 40 may be connected to the wire 20. That is, the catheter 1 may further have an electrode 40 connected to the wire 20. The electrode 40 connected to the wire 20 is, for example, disposed on the outer surface of the shaft 10. Also, although not shown, a sensor may be connected to the wire 20.

[0015] The shaft 10 may have a single lumen structure with one lumen or a multi-lumen structure with multiple lumens. Among them, the shaft 10 preferably has a single lumen structure with one lumen. When the shaft 10 has a single lumen structure, since there is no partition wall or the like inside the shaft 10 that divides the lumen, the internal space of the shaft 10 can be enlarged. Therefore, it becomes easier to insert the conducting wire 20 into the lumen of the shaft 10.

[0016] Examples of the material constituting the shaft 10 include polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon, polyester resins such as PET, aromatic polyether ketone resins such as PEEK, polyether polyamide resins, polyurethane resins, polyimide resins, fluorine resins such as PTFE, PFA, and ETFE, and synthetic resins such as polyvinyl chloride resins. The shaft 10 may have a single-layer structure or a multi-layer structure. When the shaft 10 has a multi-layer structure, for example, a structure using a metal braid such as stainless steel, carbon steel, or nickel-titanium alloy can be adopted as the intermediate layer of the resin tube constituting the shaft 10. The material constituting the shaft 10 is preferably a fluorine resin, and more preferably PTFE. Since the material constituting the shaft 10 is a fluorine resin, the lubricity of the outer surface is improved, and appropriate rigidity can be imparted, so that the catheter 1 having good insertability into the blood vessel can be obtained.

[0017] The length of the shaft 10 in the longitudinal axis direction can be selected to be appropriate for the treatment using the catheter 1. For example, the length of the shaft 10 in the longitudinal axis direction can be 500 mm or more and 2000 mm or less. The length of the shaft 10 in the longitudinal axis direction indicates the length from the distal end 10d of the shaft 10 to the proximal end 10p of the shaft 10.

[0018] The outer diameter of the shaft 10 is preferably 0.5 mm or more, more preferably 0.7 mm or more, and even more preferably 1 mm or more. By setting the lower limit of the outer diameter of the shaft 10 within the above range, the shaft 10 can be given appropriate rigidity, and the pushability of the catheter 1 can be improved. Furthermore, the outer diameter of the shaft 10 is preferably 3 mm or less, more preferably 2.8 mm or less, and even more preferably 2.5 mm or less. By setting the upper limit of the outer diameter of the shaft 10 within the above range, the catheter 1 can be made smaller, improving its ability to be inserted into in vivo lumens such as blood vessels, and improving minimally invasiveness.

[0019] The thickness of the peripheral wall of the shaft 10 is preferably 50 μm or more, more preferably 100 μm or more, and even more preferably 150 μm or more. By setting the lower limit of the thickness of the shaft 10 within the above range, the rigidity of the shaft 10 can be increased, making it possible to create a catheter 1 with good insertion properties. Furthermore, the thickness of the peripheral wall of the shaft 10 is preferably 350 μm or less, more preferably 300 μm or less, and even more preferably 250 μm or less. By setting the upper limit of the thickness of the shaft 10 within the above range, the lumen of the shaft 10 can be widened, making it easier to insert the conductor 20 into the lumen of the shaft 10.

[0020] The side holes 11 are formed in the peripheral wall of the shaft 10. The side holes 11 communicate with the inside of the shaft 10 and the outside of the shaft 10.

[0021] The length of the side hole 11 in the longitudinal axis direction can be set according to the length of the electrode 40 or sensor in the longitudinal axis direction. Preferably, the length of the side hole 11 in the longitudinal axis direction is shorter than the length of the electrode 40 or sensor in the longitudinal axis direction. Preferably, the length of the side hole 11 in the longitudinal axis direction is 100 μm or more, more preferably 125 μm or more, and even more preferably 150 μm or more. By setting the lower limit of the length of the side hole 11 in the longitudinal axis direction within the above range, it is possible to easily insert the lead wire 20 into the side hole 11. Furthermore, preferably, the length of the side hole 11 in the longitudinal axis direction is 300 μm or less, more preferably 250 μm or less, and even more preferably 200 μm or less. By setting the upper limit of the length of the side hole 11 in the longitudinal axis direction within the above range, the gap between the side hole 11 and the lead wire 20 can be reduced. As a result, when using the catheter 1, it is possible to prevent fluids such as blood from entering the lumen of the shaft 10 through the gap between the side hole 11 and the lead wire 20. If the shape of the side hole 11 is circular or polygonal, it is preferable that the outer diameter of the side hole 11 be within the same range as the length in the direction perpendicular to the longitudinal axis of the side hole 11.

[0022] As shown in Figures 3 to 6, it is preferable that the shaft 10 has multiple side holes 11 in its peripheral wall. Having multiple side holes 11 in the shaft 10 allows for a catheter 1 having multiple conductors 20, and it becomes possible to insert a different conductor 20 into each side hole 11. As a result, by connecting electrodes 40, sensors, etc. to each conductor 20, a catheter 1 with multiple electrodes 40 or sensors is created, making the catheter 1 multifunctional.

[0023] If the shaft 10 has multiple side holes 11, the side holes 11 may be arranged in multiple locations in the circumferential direction of the shaft 10, or in multiple locations in the longitudinal direction of the shaft 10. Furthermore, the side holes 11 may be arranged in multiple locations in both the circumferential and longitudinal directions of the shaft 10. In particular, it is preferable that the side holes 11 are arranged in multiple locations in the longitudinal direction of the shaft 10. By arranging multiple side holes 11 in the longitudinal direction of the shaft 10, the multiple wires 20 are less likely to become entangled in the lumen of the shaft 10 when inserting the wires 20, making the process of inserting the wires 20 easier.

[0024] The lead wire 20 electrically connects the electrode 40 and sensor to an external device (not shown), such as a power supply for the catheter 1. By connecting the lead wire 20 to the external device of the catheter 1, the external device of the catheter 1 and the electrode 40 and sensor are electrically connected. Although not shown, the catheter 1 may also have a connector on its proximal side, to which the lead wire 20 is connected, and the external device and the electrode 40 and sensor may be connected by connecting the connector to the external device of the catheter 1.

[0025] The conductor 20 preferably has a core and a covering. The material constituting the core of the conductor 20 may be any conductive material, such as iron, copper, silver, stainless steel, tungsten, nickel, titanium, or alloys thereof. Among these, the material constituting the core of the conductor 20 is preferably stainless steel. Because stainless steel has straightness and rigidity, using stainless steel as the material constituting the core of the conductor 20 makes it easier to insert the conductor 20 into the lumen of the shaft 10 and also reduces the likelihood of the conductor 20 breaking.

[0026] The covering of the conductor 20 can be made of any insulating material, such as polyolefin resins like polyethylene and polypropylene, polyamide resins like nylon, polyester resins like PET, aromatic polyetherketone resins like PEEK, polyetherpolyamide resins, polyurethane resins, polyimide resins, fluororesins like PTFE, PFA, and ETFE, and polyvinyl chloride resins. Among these, the material constituting the covering of the conductor 20 is preferably a fluororesin, and more preferably PFA. By making the covering of the conductor 20 a fluororesin, the insulating properties of the conductor 20 can be improved, and the sliding properties with other objects such as other conductors 20 in the lumen of the shaft 10 can be improved, preventing damage to the covering of the conductor 20 due to contact between the covering and other objects.

[0027] Preferably, the conductor 20 has a coating on parts other than the ends that are connected to other objects such as electrodes 40 or sensors. Specifically, for example, by partially removing the coating on one end of the conductor 20 and welding this portion to the electrode 40 or sensor, one end of the conductor 20 is connected to the electrode 40 or sensor, and by partially removing the coating on the other end of the conductor 20 that is connected to an external device or connector of the catheter 1, the conductor 20 can be configured to have a coating on parts other than the ends.

[0028] The electrode 40 or sensor may be a flat plate shape such as a rectangle or square, or it may be a ring shape. If the electrode 40 or sensor is flat, at least one of the back surface (inner surface) and the front surface (outer surface) of the flat plate may be curved so as to easily conform to the curved surface of the shaft 10. In particular, the electrode 40 or sensor is preferably ring-shaped. By having a ring shape, the area of ​​the electrode 40 or sensor on the circumference of the shaft 10 can be increased, making it easier to bring the electrode 40 or sensor into contact with the target site such as the inner wall of the heart.

[0029] Examples of materials that make up the electrode 40 or sensor include metallic materials such as copper, gold, platinum, aluminum, iron, or alloys thereof. In particular, the material that makes up the electrode 40 or sensor is preferably platinum or an alloy thereof. By making the material that makes up the electrode 40 or sensor platinum or an alloy thereof, the contrast-enhancing properties of the electrode 40 or sensor to X-rays can be improved, and the position of the electrode 40 or sensor can be confirmed by using X-rays when using the catheter 1.

[0030] Methods for connecting the conductor 20 to the electrode 40 or sensor include, for example, welding, soldering, crimping, etc. Among these, welding is preferred for connecting the conductor 20 to the electrode 40 or sensor. By welding the conductor 20 to the electrode 40 or sensor, the connection between the conductor 20 and the electrode 40 or sensor can be easily and firmly established. Although not shown in the figures, the conductor 20 and the electrode 40 or sensor may also be connected via a conductive member.

[0031] To prevent oxidative degradation due to moisture in the atmosphere, etc., at the connection point between the conductor 20 and the electrode 40 or sensor, it is preferable to coat it with a resin or the like. Examples of resins that can be used for this coating include polyurethane resins and epoxy resins.

[0032] If the electrode 40 or sensor is ring-shaped, it is preferable that the conductor 20 is connected to the inside of the ring. By having the electrode 40 or sensor as a ring and the conductor 20 connected to the inside of the ring, the connection portion between the electrode 40 or sensor and the conductor 20 is not exposed to the outside, and it is possible to prevent the conductor 20 from coming off the electrode 40 or sensor due to the connection portion coming into contact with other objects or the like.

[0033] As shown in Figure 3, the distal end of the wire insertion device 30 shown in Figures 1 and 2 is placed in the lumen of the distal end of the shaft 10. This process is sometimes referred to as the wire insertion device placement process.

[0034] The distal portion of shaft 10 refers to the distal half of the length of shaft 10 in the longitudinal direction, and the proximal portion of shaft 10 refers to the proximal half of the length of shaft 10 in the longitudinal direction. The distal portion of wire insertion device 30 refers to the distal half of the length of wire insertion device 30 in the longitudinal direction, and the proximal portion of wire insertion device 30 refers to the proximal half of the length of wire insertion device 30 in the longitudinal direction.

[0035] In the wire insertion device placement process, at least a portion of the distal part of the wire insertion device 30 is placed in at least a portion of the lumen of the distal part of the shaft 10. In the wire insertion device placement process, the distal end 30d of the wire insertion device 30 may be inserted into the proximal end of the shaft 10 to place the wire insertion device 30 in the lumen of the shaft 10, but it is preferable to insert the proximal end of the wire insertion device 30 into the distal end 10d of the shaft 10 to place the wire insertion device 30 in the lumen of the shaft 10. By inserting the proximal end of the wire insertion device 30 into the distal end 10d of the shaft 10 in the wire insertion device placement process, the distal part of the wire insertion device 30 can be placed quickly and smoothly into the lumen of the distal part of the shaft 10, making the wire insertion device placement process easier to perform.

[0036] As shown in Figure 4, the process involves inserting the conductor 20 into the side hole 11 from the outside of the shaft 10 toward the lumen of the shaft 10. In other words, the end 21 of the conductor 20 is inserted into the side hole 11. This process is sometimes referred to as the conductor insertion process.

[0037] As shown in Figure 4, if an electrode 40 or sensor is connected to one end of the conductor 20, in the conductor insertion process, the other end of the conductor 20, which is the end to which the electrode 40 or sensor is not connected, is inserted into the conductor 20 side hole 11.

[0038] The wire insertion process is preferably performed after the wire insertion tool placement process. By performing the wire insertion process after the wire insertion tool placement process, the wire insertion tool 30 does not come into contact with the wire 20 when it is placed in the lumen of the shaft 10, thereby preventing damage to the wire 20 and improving the manufacturing efficiency of the catheter 1.

[0039] Before performing the wire insertion process, the ends of the wires 20 to be inserted into the side holes 11 may be sharpened. Sharpening the ends of the wires 20 means making the ends of the wires 20 pointed. By sharpening the ends of the wires 20, the ends of the wires 20 become pointed, making it easier to insert the ends of the wires 20 into the side holes 11.

[0040] Specific examples of sharpening the end of the conductor wire 20 include cutting the end of the conductor wire 20 at an angle, polishing the end of the conductor wire 20 to make it sharp, flattening the end of the conductor wire 20 by applying pressure, and, if the conductor wire 20 is composed of multiple metal wires, twisting the ends of the multiple metal wires that make up the conductor wire 20 together. Among these, it is preferable to sharpen the end of the conductor wire 20 by cutting the end of the conductor wire 20 at an angle. By sharpening the end of the conductor wire 20 by cutting it at an angle, the end of the conductor wire 20 can be easily made sharp.

[0041] As shown in Figure 5, the end 21 of the conductor 20 is positioned distal to the side hole 11 and proximal to the distal end 10d of the shaft 10. This step is sometimes referred to as the conductor placement step. The conductor placement step is performed after the conductor insertion step.

[0042] In the wire placement process, the end 21 of the wire 20 is positioned distal to the side hole 11 and proximal to the distal end 10d of the shaft 10. In other words, in the wire placement process, the end 21 of the wire 20 is not exposed from the distal end of the shaft 10. To position the end 21 of the wire 20 distal to the side hole 11, for example, in the wire insertion process, the wire 20 is inserted into the side hole 11 of the shaft 10 from outside the shaft 10, toward the inner lumen of the shaft 10 and toward the distal side of the shaft 10, and then the wire placement process is performed.

[0043] In the wire placement process, the end 21 of the wire 20 is positioned distal to the side hole 11 and proximal to the distal end 10d of the shaft 10, so that the distal end of the wire 20 is located at the distal end of the wire insertion device 30 which is positioned in the lumen of the distal part of the shaft 10. Therefore, the wire 20 is more likely to get caught in the wire insertion device 30. Details of the wire insertion device 30 will be described later.

[0044] In the wire arrangement process, it is preferable that the proximal end of the wire 20 is located outside the shaft 10. In other words, in the wire arrangement process, it is preferable that the proximal end of the wire 20 does not pass through the side hole 11 of the shaft 10 and be placed inside the lumen of the shaft 10. By having the proximal end of the wire 20 located outside the shaft 10, the length of the wire 20 inside the lumen of the shaft 10 is less likely to become unnecessarily long, preventing the wire 20 from becoming entangled inside the lumen of the shaft 10, and making it easier to smoothly insert the wire 20 into the lumen of the shaft 10.

[0045] As shown in Figure 6, the wire insertion tool 30 is removed from the proximal end 10p of the shaft 10, and the end of the wire 20 is exposed from the proximal end 10p of the shaft 10. This step is sometimes called the wire exposure step. The wire exposure step is performed after the wire placement step.

[0046] In the wire exposure process, the proximal end of the wire insertion tool 30 is exposed from the proximal end 10p of the shaft 10, and the entire wire insertion tool 30 is withdrawn from the lumen of the shaft 10. In the wire placement process, if the wire 20 is caught in the wire insertion tool 30, when the wire insertion tool 30 is withdrawn from the proximal end 10p of the shaft 10, the distal end of the wire 20 that is caught in the wire insertion tool 30 will also be exposed from the proximal end 10p of the shaft 10. As a result, the wire 20 inserted into the side hole 11 of the shaft 10 can be inserted into the lumen of the shaft 10 from the side hole 11 of the shaft 10 to the proximal end 10p of the shaft 10. Furthermore, by using the wire insertion tool 30 to perform the wire insertion tool placement process, wire insertion process, wire placement process, and wire exposure process, the insertion of the wire 20 into the shaft 10 becomes smoother and easier.

[0047] When manufacturing a catheter 1 having multiple conductors 20, including one conductor 20 and other conductors 20, and a shaft 10 having multiple side holes 11, including one side hole 11 and other side holes 11, it is preferable to perform a conductor insertion tool placement step, then perform a conductor insertion step, a conductor placement step, and a conductor exposure step for one conductor 20 and one side hole 11, and then perform the conductor insertion tool placement step again, and then perform the conductor insertion step, a conductor placement step, and a conductor exposure step for the other conductors 20 and other side holes 11. By performing the conductor insertion tool placement step, a conductor insertion step, a conductor placement step, and a conductor exposure step for one conductor 20 and one side hole 11, and then performing the conductor insertion tool placement step, a conductor insertion step, a conductor placement step, and a conductor exposure step again for the other conductors 20 and other side holes 11, the multiple conductors 20 are less likely to become entangled in the lumen of the shaft 10, and the manufacturing process of the catheter 1 can be carried out smoothly.

[0048] As shown in Figures 1 and 2, the wire insertion tool 30 has three or more wires 31, a distal fixing part 32 at the distal end 31d of the wires 31 to which the multiple wires 31 are fixed to each other, and a proximal fixing part 33 at the proximal end 31p of the wires 31 to which the multiple wires 31 are fixed to each other. The wire insertion tool 30 has multiple closed loops 34 formed by one wire 31A and other wires 31B different from the one wire 31A, and the multiple closed loops 34 are not on the same plane. The fact that the multiple closed loops 34 are not on the same plane means that the surfaces formed by each closed loop 34 are not on the same plane.

[0049] A closed loop 34 is a closed loop-shaped region formed between one wire 31A and another wire 31B that is different from the first wire 31A. The other wire 31B is the wire 31 adjacent to the first wire 31A. In Figures 1 and 2, the closed loop 34 is schematically shown with a dashed line.

[0050] The number of wires 31 in the wire insertion tool 30 is three or more. Because the wire insertion tool 30 has three or more wires 31, there are multiple closed loops 34 formed by two wires 31. Because the wire insertion tool 30 has multiple closed loops 34, and because the multiple closed loops 34 are not on the same plane, the distal part of the wire insertion tool 30 where the multiple closed loops 34 are located has a three-dimensional shape. This makes it easier for the wire 20 to enter the closed loops 34 during the wire insertion process and the wire arrangement process, making it easier for the wire 20 to catch on the wire insertion tool 30, and thus easier to insert the wire 20 into the lumen of the shaft 10.

[0051] The number of wires 31 in the wire insertion tool 30 may be three or more, but it is preferable to have four or more, more preferably five or more, and even more preferably six or more. By setting the lower limit of the number of wires 31 in the wire insertion tool 30 to the above range, the number of closed loops 34 in the wire insertion tool 30 increases, making it easier for the conductor 20 to enter the closed loops 34. Furthermore, the number of wires 31 in the wire insertion tool 30 is preferably 15 or less, more preferably 10 or less, and even more preferably 7 or less. By setting the upper limit of the number of wires 31 in the wire insertion tool 30 to the above range, the outer diameter of the wire insertion tool 30 can be reduced, making it easier to insert the wire insertion tool 30 into the lumen of the shaft 10.

[0052] The materials constituting the wire 31 include metal wires and fibers. Examples of materials constituting metal wires include stainless steel such as SUS304 and SUS316, carbon steel, platinum, nickel, cobalt, chromium, titanium, tungsten, gold, nickel-titanium alloy, cobalt-chromium alloy, and tungsten alloy. The metal wire may be a single wire or a stranded wire. Examples of materials constituting fibers include polyarylate fibers, aramid fibers, ultra-high molecular weight polyethylene fibers, PBO fibers, and carbon fibers. The fibers may be monofilaments or multifilaments.

[0053] In particular, the material constituting the wire 31 is preferably a metal wire, and more preferably a metal wire made of stainless steel. By using a stainless steel metal wire as the material constituting the wire 31, the wire 31 becomes highly elastic, making it easy to insert into the lumen of the shaft 10 and resulting in a highly durable wire insertion tool 30.

[0054] Three or more wires 31 are fixed at their distal ends 31d by distal fixing parts 32 and at their proximal ends 31p by proximal fixing parts 33. It is preferable that the wires 31 positioned between the distal fixing parts 32 and the proximal fixing parts 33 are in a bent state. In other words, it is preferable that the length of the wires 31 positioned between the distal fixing parts 32 and the proximal fixing parts 33 along the extending direction is longer than the shortest distance between the distal fixing parts 32 and the proximal fixing parts 33. By having the wires 31 positioned between the distal fixing parts 32 and the proximal fixing parts 33 in a bent state, the size of the closed loop 34 formed by one wire 31A and the other wires 31B tends to increase, making it easier for the conductor 20 to enter the closed loop 34.

[0055] Preferably, the length of the wire insertion device 30 from its distal end 30d to its proximal end is longer than the length of the shaft 10 from its distal end 10d to its proximal end 10p. When the length of the wire insertion device 30 in the longitudinal axis direction is longer than the length of the shaft 10, the proximal end of the wire insertion device 30 is more easily exposed to the outside of the shaft 10 from the proximal end 10p when the distal end of the wire insertion device 30 is placed in the lumen of the distal end of the shaft 10 during the wire insertion device placement process. As a result, the wire insertion device 30 can be easily removed from the proximal end 10p of the shaft 10 during the wire exposure process that follows the wire insertion device placement process, enabling smooth manufacturing of the catheter 1.

[0056] Preferably, at least a portion of the closed loop 34 of the wire insertion tool 30 is located at the distal end of the wire insertion tool 30, and more preferably, the entire closed loop 34 is located at the distal end of the wire insertion tool 30. In other words, in the wire insertion tool placement process, it is preferable to place at least a portion of the closed loop 34 of the wire insertion tool 30 in the lumen of the distal end of the shaft 10. By placing at least a portion of the closed loop 34 in the lumen of the distal end of the shaft 10, the wire 20 can easily enter the closed loop 34 and be inserted into the lumen of the shaft 10 during the wire insertion process and the wire placement process.

[0057] In the distal fixing portion 32 and the proximal fixing portion 33, the multiple wires 31 may be directly fixed to each other, or they may be fixed via other parts. Methods for directly fixing the multiple wires 31 to each other include welding, brazing with solder, bonding with adhesive, twisting and fixing the multiple wires 31, or a combination thereof. Methods for fixing the multiple wires 31 via other parts include welding, bonding, engagement using cylindrical, polygonal, or C-shaped cross-section members, crimping using crimping fittings, fixing using heat shrink tubing, or a combination thereof.

[0058] As shown in Figure 1, the wire insertion device 30 has a distal cylindrical member 35 in the distal fixing portion 32 and a proximal cylindrical member 36 in the proximal fixing portion 33. Preferably, multiple wires 31 are arranged in the lumen of the distal cylindrical member 35 and multiple wires 31 are arranged in the lumen of the proximal cylindrical member 36. The configuration of the wire insertion device 30, in which multiple wires 31 are arranged in the lumen of the distal cylindrical member 35 in the distal fixing portion 32 and multiple wires 31 are arranged in the lumen of the proximal cylindrical member 36 in the proximal fixing portion 33, makes it easier to firmly fix the multiple wires 31 in the distal fixing portion 32 and the proximal fixing portion 33.

[0059] Preferably, the wire insertion tool 30 has the distal end 31d of the wire 31 positioned in the lumen of the distal cylindrical member 35 and the proximal end 31p of the wire 31 positioned in the lumen of the proximal cylindrical member 36. Because the distal end 31d of the wire 31 is positioned in the lumen of the distal cylindrical member 35 and the proximal end 31p of the wire 31 is positioned in the lumen of the proximal cylindrical member 36, the end of the wire 31 is not exposed. Therefore, when inserting the wire insertion tool 30 into the lumen of the shaft 10, it is less likely that the end of the wire 31 will damage the shaft 10.

[0060] Examples of materials that make up the distal cylindrical member 35 and the proximal cylindrical member 36 include metals such as stainless steel (SUS304, SUS316, etc.), carbon steel, platinum, nickel, cobalt, chromium, titanium, tungsten, gold, nickel-titanium alloy, cobalt-chromium alloy, and tungsten alloy, as well as synthetic resins such as polyolefin resins (PP, polyethylene (PE), polyester resins (PET), polycarbonate resin, ABS resin, and polyurethane resin.

[0061] In particular, the materials constituting the distal cylindrical member 35 and the proximal cylindrical member 36 are preferably metal, and more preferably stainless steel. By using metal as the material constituting the distal cylindrical member 35 and the proximal cylindrical member 36, the strength of the distal cylindrical member 35 and the proximal cylindrical member 36 can be increased.

[0062] Preferably, in the distal fixing portion 32, multiple wires 31 are arranged in the lumen of the distal cylindrical member 35 and fixed to the distal cylindrical member 35 by welding, and in the proximal fixing portion 33, multiple wires 31 are arranged in the lumen of the proximal cylindrical member 36 and fixed to the proximal cylindrical member 36 by welding. By fixing the multiple wires 31 to the distal cylindrical member 35 by welding in the distal fixing portion 32 and the multiple wires 31 to the proximal cylindrical member 36 by welding in the proximal fixing portion 33, the multiple wires 31 can be firmly fixed, and the wires 31 are less likely to come loose in the distal fixing portion 32 and the proximal fixing portion 33.

[0063] As shown in Figures 1 and 2, the wire insertion tool 30 has a first wire 311 and a second wire 312 adjacent to the first wire 311. Preferably, the angle θ1 formed by a straight line L1 connecting the center P2 of the inscribed circle C1 of the multiple wires 31 and the center P3 of the outer shape of the first wire 311, and a straight line L2 connecting the center P2 of the inscribed circle C1 of the multiple wires 31 and the center P4 of the outer shape of the second wire 312, in a cross section perpendicular to the longitudinal axis of the wire 31 at the midpoint P1 of the length of the wire 31 in the longitudinal axis direction, is between 30 degrees and 120 degrees. The inscribed circle C1 of the multiple wires 31 refers to a circle inscribed in at least two wires 31 in a cross section perpendicular to the longitudinal axis of the wires 31, out of the three or more wires 31 that the wire insertion tool 30 has. The angle θ1 between the straight line L1 and the straight line L2 is between 30 degrees and 120 degrees, which makes it easier to ensure a sufficient size for the closed loop 34 formed by the first wire 311 and the second wire 312. As a result, when the wire insertion tool 30 is placed inside the lumen of the shaft 10, the wire 20 can easily enter the closed loop 34, making it easier to insert the wire 20 into the lumen of the shaft 10.

[0064] In a cross-section perpendicular to the longitudinal axis of the wire 31 at the midpoint P1 of the length of the wire 31 in the longitudinal axis direction, the angle θ1 formed by the line L1 connecting the center P2 of the inscribed circle C1 of the multiple wires 31 and the center P3 of the outer shape of the first wire 311, and the line L2 connecting the center P2 of the inscribed circle C1 of the multiple wires 31 and the center P4 of the outer shape of the second wire 312, is preferably 35 degrees or more, more preferably 40 degrees or more, and even more preferably 45 degrees or more. By setting the lower limit of the angle θ1 formed by the line L1 and the line L2 to the above range, the size of the closed loop 34 formed by the first wire 311 and the second wire 312 tends to increase, and the conductor 20 tends to enter the closed loop 34. Furthermore, in a cross-section perpendicular to the longitudinal axis of the wire 31 at the midpoint P1 of the length of the wire 31 in the longitudinal axis direction, the angle θ1 formed by the straight line L1 connecting the center P2 of the inscribed circle C1 of the multiple wires 31 and the center P3 of the outer shape of the first wire 311, and the straight line L2 connecting the center P2 of the inscribed circle C1 of the multiple wires 31 and the center P4 of the outer shape of the second wire 312, is preferably 110 degrees or less, more preferably 100 degrees or less, and even more preferably 95 degrees or less. By setting the upper limit of the angle θ1 formed by the straight line L1 and the straight line L2 within the above range, the wire insertion device 30 will have multiple closed loops 34 of a certain size, making it easier for the wire 20 to enter the closed loops 34 in the lumen of the shaft 10.

[0065] The shape of the wire 31 in a cross-section perpendicular to the longitudinal axis can be circular, elliptical, polygonal, or a combination thereof. Among these, a circular cross-sectional shape of the wire 31 is preferred. A circular cross-sectional shape of the wire 31 results in a smooth outer surface. Therefore, when the wire insertion device 30 is placed in the lumen of the shaft 10, the sliding properties of the wire insertion device 30 are improved, and the inner surface of the shaft 10 is less likely to be damaged by contact with the wire 31.

[0066] The shape of the wire 31 in the longitudinal axis direction can be a straight line, an arc, a corrugated shape, a zigzag shape, or a combination thereof. Among these, a corrugated shape for the wire 31 is preferable. The corrugated shape of the wire 31 makes it easier for the conductor 20 to catch on the wire 31. Therefore, the conductor 20 that has entered the closed loop 34 formed by one wire 31A and the other wire 31B is more likely to catch on the wire 31, making it less likely for the conductor 20 to fall out of the closed loop 34, and making it easier to insert the conductor 20 into the lumen of the shaft 10.

[0067] As shown in Figure 1, the wire insertion tool 30 may have a long member 50 on the proximal side of the wire 31 that is different from the wire 31. In other words, the wire insertion tool 30 may further have a long member 50, and the wire 31 may be positioned at the distal end of the long member 50. The presence of the long member 50 further increases the rigidity of the proximal part of the wire insertion tool 30, making it easier to insert the wire insertion tool 30 into the lumen of the shaft 10.

[0068] Examples of materials that make up the long member 50 include metals such as stainless steel (SUS304, SUS316, etc.), carbon steel, platinum, nickel, cobalt, chromium, titanium, tungsten, gold, nickel-titanium alloy, cobalt-chromium alloy, and tungsten alloy, as well as synthetic resins such as polyolefin resins (PP, polyethylene (PE), polyester resins (PET), polycarbonate resin, ABS resin, and polyurethane resin.

[0069] In particular, the material constituting the elongated member 50 is preferably metal, and more preferably stainless steel. The fact that the elongated member 50 is made of metal gives it strength and elasticity, making it easier to smoothly insert the wire insertion tool 30 into the lumen of the shaft 10.

[0070] The shape of the elongated member 50 in a cross-section perpendicular to the longitudinal axis can be circular, elliptical, polygonal, or a combination thereof. Among these, a circular cross-sectional shape of the elongated member 50 is preferable. A circular cross-sectional shape of the elongated member 50 makes the outer surface of the elongated member 50 smooth, thereby improving sliding properties. As a result, when placing the wire insertion device 30 into the lumen of the shaft 10, it becomes easier to smoothly insert the wire insertion device 30.

[0071] The outer dimensions of the elongated member 50 in the longitudinal axis direction are preferably larger than the outer dimensions of the wire 31. The outer dimensions of the elongated member 50 refer to the diameter of the circumscribed circle of the cross-sectional shape of the elongated member 50. The outer dimensions of the wire 31 refer to the diameter of the circumscribed circle of the cross-sectional shape of the wire 31. By making the outer dimensions of the elongated member 50 larger than the outer dimensions of the wire 31, the rigidity of the proximal part of the wire insertion device 30 is easily increased, and the ease of insertion of the wire insertion device 30 into the lumen of the shaft 10 can be improved.

[0072] Methods for connecting the long member 50 and the wire 31 include welding, brazing with solder or similar, bonding with adhesive, engagement using cylindrical, polygonal, or C-shaped members with notches in the cross-section, crimping, or combinations thereof. "Connection" includes both direct connections between the two elements and indirect connections between the two elements via one or more other elements.

[0073] In particular, it is preferable that the wire insertion tool 30 has a proximal cylindrical member 36 in the proximal fixing portion 33, and that the distal end 50d of the long member 50 is placed in the lumen of the proximal cylindrical member 36, thereby connecting the long member 50 and the wire 31. By connecting the long member 50 and the wire 31 via the proximal cylindrical member 36, the connection strength between the long member 50 and the wire 31 can be easily increased.

[0074] As shown in Figures 3 to 6, the shaft 10 has a first side hole 111 at the distal end and a second side hole 112 at the proximal end in the longitudinal axis direction of the shaft 10. Preferably, the length D1 from the distal end 31d to the proximal end 31p of the wire 31 in the longitudinal axis direction of the wire insertion device 30 is longer than the length D2 from the first side hole 111 to the second side hole 112 of the shaft 10. Note that the length D2 from the first side hole 111 to the second side hole 112 of the shaft 10 refers to the shortest distance from the distal end of the first side hole 111 to the proximal end of the second side hole 112 in the longitudinal axis direction of the shaft 10.

[0075] Because the length D1 from the distal end 31d to the proximal end 31p of the wire 31 is longer than the length D2 from the first side hole 111 to the second side hole 112, when the distal end of the wire insertion device 30 is placed in the lumen of the distal end of the shaft 10 during the wire insertion device placement process, the closed loop 34 of the wire insertion device 30 is more likely to be present at both the position of the first side hole 111 and the position of the second side hole 112. Therefore, during the wire insertion process, the end 21 of the wire 20 inserted into the side hole 11 is more likely to enter the closed loop 34 of the wire insertion device 30, the wire 20 is more likely to catch on the wire insertion device 30, and it is easier to smoothly expose the wire 20 from the shaft 10 by removing the wire insertion device 30 from the shaft 10. In other words, it is possible to increase the manufacturing efficiency of catheter 1 having multiple wires 20.

[0076] The length D1 of the wire insertion tool 30, from the distal end 31d to the proximal end 31p of the wire 31 in the longitudinal axis direction, is preferably 1.1 times or more, more preferably 1.2 times or more, and even more preferably 1.3 times or more, the length D2 of the shaft 10 from the first side hole 111 to the second side hole 112. By setting the lower limit of the ratio of the length D1 of the wire 31 to the length D2 of the first side hole 111 to the second side hole 112 within the above range, the closed loop 34 of the wire insertion tool 30 is more easily positioned at the positions of the first side hole 111 and the second side hole 112, and the end 21 of the conductor 20 inserted into the side hole 11 is more easily entered into the closed loop 34. Furthermore, the length D1 of the wire 31 from the distal end 31d to the proximal end 31p in the longitudinal axis direction of the wire insertion tool 30 is preferably 3 times or less, more preferably 2.5 times or less, and even more preferably 2 times or less, the length D2 of the shaft 10 from the first side hole 111 to the second side hole 112. By setting the upper limit of the ratio of the length D1 of the wire 31 to the length D2 of the shaft 10 from the first side hole 111 to the second side hole 112 within the above range, the length of the wire 31 is less likely to become unnecessarily long. As a result, the rigidity of the distal part of the wire insertion tool 30 is increased, and a wire insertion tool 30 with good insertion into the shaft 10 can be made. [Explanation of Symbols]

[0077] 1: Catheter 10: Shaft 10d: Distal end of the shaft 10p: Proximal end of the shaft 11: Side hole 111: 1st side hole 112:Second side hole 20: Conductor 21: End of the wire 30: Wire insertion tool 30d: Distal end of the wire insertion device 31: Wire rod 31d: Distal end of the wire 31p: Proximal end of the wire 31A: First wire 31B: Other wire materials 311: First wire 312: Second wire 32: Distal fixation part 33: Proximal fixation part 34: Closed Loop 35: Distal cylindrical member 36: Proximal cylindrical member 40: Electrode 50: Long components 50d: Distal end of long member C1: Inscribed circle of a wire P1: Midpoint of the length along the longitudinal axis of the wire. P2: Center of the inscribed circle of the wire P3: Center of the outer shape of the first wire P4: Center of the outer shape of the second wire L1: A straight line connecting center P2 and center P3. L2: A straight line connecting the center P2 and the center P4. θ1: Angle formed by line L1 and line L2 D1: Length from the distal end of the wire to the proximal end of the wire D2: Length from the first side hole to the second side hole

Claims

1. A method for manufacturing a catheter comprising a shaft having a lumen extending in the longitudinal direction and side holes in its circumferential wall, and a conductor inserted into the lumen of the shaft, The process involves placing the distal end of the wire insertion device into the lumen of the distal end of the shaft, A step of inserting the conductor into the side hole from the outside of the shaft toward the inner lumen of the shaft, The steps include positioning the end of the conductor distal to the side hole and proximal to the distal end of the shaft, The process includes removing the wire insertion tool from the proximal end of the shaft and exposing the wire from the proximal end of the shaft, The wire insertion device comprises three or more wires, a distal fixing portion at the distal end of each wire to which multiple wires are fixed to each other, and a proximal fixing portion at the proximal end of each wire to which multiple wires are fixed to each other. The wire insertion device has multiple closed loops formed by one wire and another wire different from the first wire. A method for manufacturing a catheter in which the multiple closed loops are not on the same plane.

2. The wire insertion device has a distal cylindrical member in the distal fixing portion and a proximal cylindrical member in the proximal fixing portion, Multiple wires are arranged in the lumen of the distal cylindrical member. The method for manufacturing a catheter according to claim 1, wherein a plurality of the wires are arranged in the lumen of the proximal cylindrical member.

3. The wire insertion device comprises a first wire and a second wire adjacent to the first wire. A method for manufacturing a catheter according to claim 1 or 2, wherein, in a cross section perpendicular to the longitudinal axis of the wire at the midpoint of the length of the wire in the longitudinal axis direction, the angle formed by a straight line connecting the centers of the inscribed circles of the plurality of wires and the center of the outer shape of the first wire, and a straight line connecting the centers of the inscribed circles of the plurality of wires and the center of the outer shape of the second wire, is 30 degrees or more and 120 degrees or less.

4. The method for manufacturing a catheter according to claim 1 or 2, wherein the wire has a corrugated shape.

5. The shaft has a first side hole located at the distal end and a second side hole located at the proximal end in the longitudinal axis direction of the shaft. A method for manufacturing a catheter according to claim 1 or 2, wherein the length from the distal end to the proximal end of the wire in the longitudinal axis direction of the wire insertion device is longer than the length from the first side hole to the second side hole of the shaft.

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