Electrode catheter and method for manufacturing the electrode catheter

Abstract

To provide an electrode catheter in which a gap is hardly generated between a conductor wire hole formed on a shaft and a conductor wire, and which can be produced easily, and a production method of the electrode catheter.SOLUTION: There is provided a production method of an electrode catheter 1 comprising: a preparing step for preparing, a shaft 10 which extends in a longitudinal axis direction and has a lumen, an electrode 20, and a conductor wire 30; a recess formation step for forming a bottomed recess 11 on a pipe wall of the shaft 10; a hole formation step for piercing a first end of the conductor wire 30 on a bottom part 12 of the recess 11, for forming a hole 13 in which the lumen communicates with an outside, on the shaft 10; a conductor wire connecting step for connecting a second end 32 of the conductor wire 30 to the electrode 20; and an electrode arranging step for arranging the electrode 20 on the outside of the hole 13.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an electrode catheter used for measuring the potential of internal organs, mainly the heart, and for cauterizing internal tissues, and a method for manufacturing the electrode catheter.

Background Art

[0002] Electrode catheters are mainly used as medical devices for diagnosing arrhythmias by measuring the potential of the heart and for cauterizing internal tissues by passing a high-frequency current to treat arrhythmias. Generally, in an electrode catheter, a plurality of ring-shaped electrodes are arranged outside a cylindrical body (shaft) having a lumen. A conducting wire connected to the inside of the ring-shaped electrode extends from a wire hole provided in the shaft through the lumen of the shaft to an electrocardiograph. A connector is used to connect the conducting wire to the electrocardiograph. For example, by inserting the electrode catheter into a patient's heart and connecting the connector to the electrocardiograph, it is possible to accurately grasp the state of the myocardium, which is the cause of arrhythmias, by measuring the electrocardiogram near the ring-shaped electrode portion.

[0003] When a liquid such as blood enters the gap between the electrode and the shaft and flows into the lumen of the shaft through the wire hole, a short circuit may occur between the plurality of conducting wires, or corrosion of the conducting wires or internal structures of the electrode catheter may occur, which may cause the electrode catheter to malfunction. In addition, when a liquid enters the lumen of the shaft, a so-called drift phenomenon occurs, in which the baseline potential of the electrocardiogram measured by the electrode catheter becomes unstable, making it difficult to perform accurate potential measurement and cauterization. In order to prevent the malfunction of the electrode catheter and to perform accurate potential measurement and cauterization with the electrode catheter, it is necessary to prevent the intrusion of liquid into the lumen of the shaft.

[0004] As an electrode catheter in which liquid hardly penetrates into the lumen of a shaft, for example, Patent Document 1 discloses an electrode catheter comprising a catheter body, a control handle, a catheter tip, a plurality of ring-shaped electrodes, and a plurality of lead wires. Side holes extending from the outer peripheral surface to the lumen are formed in the tube wall of the catheter tip corresponding to the fixing positions of the ring-shaped electrodes. Each of the plurality of lead wires is connected to the corresponding ring-shaped electrode by being joined to the inner peripheral surface of the ring-shaped electrode at its tip portion, enters the lumen of the catheter tip from the side holes, extends through the lumen of the catheter tip, the lumen of the catheter body, and the inner hole of the control handle, and an insulating resin thin film is formed on the surface of the metal core wire at least at the tip portion of the lead wire and on the surface of the joint portion with the inner peripheral surface of the ring-shaped electrode.

[0005] Patent Document 2 discloses a catheter including a resin tube and a ring-shaped electrode disposed outside the resin tube. The outer surface of the ring-shaped electrode is located inside the outer surface of the resin tube where the ring-shaped electrode is not disposed. A conducting wire electrically connected to an external power source is attached to the ring-shaped electrode. The conducting wire passes through a hole penetrating the resin tube in the radial direction and is in close contact with the inner surface of the hole. It is described that the long axis direction of the opening surface of the hole is parallel to the length direction of the resin tube, for example, in an elliptical shape.

[0006] Patent Document 3 discloses an electrode catheter having a cylindrical body with an opening formed on its side surface, a ring electrode covering the opening of the cylindrical body from the outside, a conductive member connected to the ring electrode and closing at least a part of the opening, and a conducting wire connected to the conductive member and disposed inside the cylindrical body. The opening area of the opening decreases toward the axis of the cylindrical body, and the conductive member has a tapered portion that tapers toward the axis of the cylindrical body.

[0007] Patent Document 4 discloses a guide wire type electrode catheter having a tube body, a connector, and an electrode group composed of a plurality of electrodes. The tube body is provided with an electrode group formed by connecting and fixing the tip of a lead wire to the side surface on the tip side, and side holes corresponding to the fixed positions of the electrode group. The lead wire extends from the side holes through the inside of the tube body to the connector. The electrode is formed by welding and joining a portion of a metal core wire with the resin coating peeled off at the tip inside by resistance welding or the like to the electrode, and connecting the rear end of the lead wire welded to the electrode through the inside of the tube body from the side holes to the connector. A sealing agent is provided in the gaps between both side surfaces of the tip side and the rear end side of the electrode, between the electrode and the outer peripheral surface of the first tube body, and between the inside of the electrode and the lead wire at the side holes of the first tube body. It is described that the metal core wire of the lead wire is adhesively joined in the sealing agent including the resin coating so as not to be exposed from the sealing agent.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0009] In the electrode catheter of Patent Document 1, an insulating resin thin film is formed on the surface of the metal core wire at the tip portion of the lead wire and on the surface of the joint portion between the inner peripheral surface of the ring-shaped electrode. However, it is highly difficult to form the insulating resin thin film so that no gap is generated between the ring-shaped electrode, the lead wire, and the catheter tube wall, and it has been difficult to improve the manufacturing efficiency.

[0010] In the catheter of Patent Document 2, a ring-shaped electrode and a conducting wire are brought into close contact with a resin tube by thermally expanding the resin tube. However, it may be difficult to precisely adjust the expansion of the resin tube, and there is room for improvement in terms of facilitating manufacturing.

[0011] In the electrode catheter of Patent Document 3, in the manufacture of the electrode catheter, it may be difficult to form an opening in the cylindrical body whose opening area becomes smaller toward the axis of the cylindrical body, or to manufacture a conductive member having a tapered portion that tapers toward the axis of the cylindrical body.

[0012] In the electrode catheter of Patent Document 4, sealing agents are provided on both side surfaces of the front end side and the rear end side of the electrode, in the gap between the electrode and the outer peripheral surface of the first tube body, and in the gap between the inside of the electrode and the lead wire at the side holes of the first tube body. However, it is difficult to provide the sealing agent without gaps, and the manufacturing difficulty is high.

[0013] The present invention has been made in view of the above circumstances, and an object thereof is to provide an electrode catheter in which a gap is less likely to occur between a wire hole formed in a shaft and a conducting wire, and which is easy to manufacture, and a method for manufacturing the electrode catheter.

Means for Solving the Problems

[0014] A method for manufacturing an electrode catheter capable of solving the above problems includes a preparation step of preparing a shaft extending in the longitudinal axis direction and having a lumen, an electrode, and a conducting wire; a recess forming step of forming a bottomed recess in the tube wall of the shaft; a hole forming step of piercing the first end of the conducting wire into the bottom of the recess to form a hole through which the lumen and the outside communicate in the shaft; a conducting wire connecting step of connecting the second end of the conducting wire to the electrode; and an electrode arranging step of arranging the electrode outside the hole.

[0015] In the method for manufacturing an electrode catheter of the present invention, it is preferable that the area of the bottom of the recess is larger than the area of the hole in a cross section perpendicular to the depth direction of the hole.

[0016] In the method for manufacturing the electrode catheter of the present invention, after the recess forming step, it is preferable that the depth of the recess is longer than the shortest distance from the bottom of the recess to the inner surface of the shaft.

[0017] In the method for manufacturing the electrode catheter of the present invention, it is preferable that the length of the bottom of the recess in the longitudinal axis direction of the shaft is shorter than the length of the electrode in the longitudinal axis direction of the shaft.

[0018] In the method for manufacturing the electrode catheter of the present invention, it is preferable that the area of the bottom of the recess is larger than the cross-sectional area perpendicular to the longitudinal axis direction of the conducting wire.

[0019] In the method for manufacturing the electrode catheter of the present invention, after the electrode arrangement step, it is preferable that the second end of the conducting wire is located outside the shaft.

[0020] In the method for manufacturing the electrode catheter of the present invention, it is preferable to have a conducting wire adhesion step of fixing the conducting wire to the hole with an adhesive after the hole forming step.

[0021] The electrode catheter that has solved the above problems has a shaft that extends in the longitudinal axis direction, has a lumen, and has a hole through which the lumen and the outer surface communicate, an electrode disposed outside the hole, and a conducting wire connected to the electrode and extending into the lumen of the shaft through the hole. The shaft has a bottomed recess in the tube wall of the shaft, the hole is provided at the bottom of the recess, the bottom of the recess is circular, and the area of the bottom of the recess is smaller than the area of the inner surface of the electrode.

[0022] In the electrode catheter of the present invention, it is preferable that the area of the bottom of the recess is larger than the area of the hole in a cross-section perpendicular to the depth direction of the hole.

[0023] In the electrode catheter of the present invention, it is preferable that the depth of the recess is longer than the shortest distance from the bottom of the recess to the inner surface of the shaft.

[0024] In the electrode catheter of the present invention, it is preferable that the length of the bottom of the recess in the longitudinal axis direction of the shaft is shorter than the length of the electrode in the longitudinal axis direction of the shaft.

[0025] In the electrode catheter of the present invention, it is preferable that the area of the bottom of the recess is larger than the cross-sectional area perpendicular to the longitudinal axis direction of the conducting wire.

[0026] In the electrode catheter of the present invention, it is preferable that the second end of the conducting wire is located outside the shaft.

[0027] In the electrode catheter of the present invention, in the portion of the hole in the inner cavity of the shaft, it is preferable that the inner wall of the shaft protrudes toward the center side of the longitudinal axis of the shaft.

Advantages of the Invention

[0028] According to the manufacturing method of the electrode catheter of the present invention, by having a recess forming step of forming a bottomed recess in the tube wall of the shaft and a hole forming step of piercing the first end of the conducting wire into the bottom of the recess to form a hole through which the inner cavity and the outside of the shaft communicate, it becomes difficult for a gap to occur between the conducting wire and the hole. Therefore, an electrode catheter in which it is difficult for a liquid such as blood to enter the inner cavity of the shaft can be easily manufactured.

[0029] Also, according to the electrode catheter of the present invention, since the shaft has a bottomed recess in the tube wall of the shaft, the hole is provided at the bottom of the recess, the bottom of the recess is circular, and the area of the bottom of the recess is smaller than the area of the inner surface of the electrode, it becomes difficult for a gap to occur between the conducting wire and the hole. As a result, it is possible to make it difficult for a liquid such as blood to enter the inner cavity of the shaft.

Brief Description of the Drawings

[0030]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0031] 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 range 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 convenience, hatching, reference numerals of members, 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 differ from the actual dimensions because priority is given to facilitating the understanding of the features of the present invention.

[0032] FIG. 1 is an overall view of the electrode catheter 1 in one embodiment of the present invention, and FIG. 2 is a cross-sectional view along the longitudinal axis of the distal end portion of the electrode catheter 1. As shown in FIGS. 1 and 2, the electrode catheter 1 includes a shaft 10 that extends in the longitudinal axis direction and has a lumen, an electrode 20, and a wire 30.

[0033] 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 side opposite to the proximal side, that is, the side of the treatment target. Also, the extending direction of the shaft 10 is referred to as the longitudinal axis direction. The longitudinal axis direction can also be referred to as the proximal-distal direction. The radial direction refers to the radial direction of the shaft 10. In the radial direction, the inner side refers to the direction toward the center of the longitudinal axis of the shaft 10, and the outer side in the radial direction refers to the direction opposite to the inner side. In FIGS. 1 and 2, the right side of the figure is the proximal side, and the left side of the figure is the distal side.

[0034] First, a manufacturing method of the electrode catheter 1 will be described.

[0035] The electrode catheter 1 is, for example, inserted from its distal side through the patient's blood vessel to reach the heart, and is used for examination, treatment, defibrillation, etc. of arrhythmia in the heart.

[0036] The manufacturing method of the electrode catheter 1 includes a preparation step of preparing a shaft 10 extending in the longitudinal axis direction and having a lumen, an electrode 20, and a conducting wire 30; a recess forming step of forming a bottomed recess 11 in the tube wall of the shaft 10; a hole forming step of piercing the first end 31 of the conducting wire 30 into the bottom 12 of the recess 11 to form a hole 13 through which the lumen and the outside communicate with each other in the shaft 10; a conducting wire connection step of connecting the second end 32 of the conducting wire 30 to the electrode 20; and an electrode arrangement step of arranging the electrode 20 outside the hole 13.

[0037] The preparation step prepares a shaft 10 extending in the longitudinal axis direction and having a lumen, an electrode 20, and a conducting wire 30.

[0038] The shaft 10 may have a single lumen structure with one lumen or a multi-lumen structure with a plurality of lumens. If the number of lumens in the shaft 10 is one, since there is no partition wall or the like inside the shaft to divide the lumen, the flexibility of the shaft 10 can be increased, and the insertability of the electrode catheter 1 can be improved. If the number of lumens in the shaft 10 is plural, by arranging the plurality of conducting wires 30 and the like arranged in the lumens in different lumens respectively, it is possible to prevent the conducting wire 30 from contacting another conducting wire 30 or the like, and prevent damage such as disconnection of the conducting wire 30.

[0039] The shaft 10 includes, for example, 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 used as the intermediate layer of the resin tube constituting the shaft 10. The material constituting the shaft 10 is preferably a polyamide resin, and more preferably a polyamide elastomer. Since the material constituting the shaft 10 is a polyamide elastomer, the slidability of the outer surface of the shaft 10 is good, and since the shaft 10 has appropriate rigidity, the electrode catheter 1 with good insertability into blood vessels can be obtained.

[0040] The length of the shaft 10 in the longitudinal axis direction can be selected to be appropriate for the treatment. For example, the length of the shaft 10 in the longitudinal axis direction can be 500 mm or more and 1500 mm or less.

[0041] 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 value of the outer diameter of the shaft 10 within the above range, appropriate rigidity can be imparted to the shaft 10, and the electrode catheter 1 with high insertability into blood vessels can be obtained. Further, 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 value of the outer diameter of the shaft 10 within the above range, it is possible to prevent the outer diameter of the electrode catheter 1 from becoming too large and enhance invasiveness.

[0042] The thickness 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 value of the thickness of the shaft 10 within the above range, the rigidity of the shaft 10 can be enhanced, and the electrode catheter 1 with good insertability into blood vessels can be obtained. Further, the thickness 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 value of the thickness of the shaft 10 within the above range, the lumen of the shaft 10 can be widened, and the electrode 20 of the electrode catheter 1 can be multi-polarized.

[0043] The electrode 20 may be a ring-shaped electrode or a flat electrode having a shape such as a rectangle or a square. When the electrode 20 is a flat electrode, at least one of the back surface (inner surface) and the front surface (outer surface) of the flat electrode may be a curved surface so as to easily follow the curved surface of the surface of the shaft 10. Among them, the electrode 20 is preferably ring-shaped. When the electrode 20 is a ring-shaped electrode, the area of the electrode 20 on the circumference of the shaft 10 can be increased, and it becomes easier to bring the electrode 20 into contact with a target site such as the inner wall of the heart.

[0044] Examples of the material constituting the electrode 20 include metal materials such as copper, gold, platinum, aluminum, iron, or alloys thereof. Among these, the material constituting the electrode 20 is preferably platinum or an alloy thereof. By configuring the electrode 20 in this way, the contrast of the electrode 20 with respect to X-rays can be enhanced, and the position of the electrode 20 can be confirmed by using X-rays when the electrode catheter 1 is used.

[0045] The number of the electrodes 20 is preferably plural. When the number of the electrodes 20 is plural, the sizes of the respective electrodes 20 may be the same or different. The fact that the sizes of the respective electrodes 20 are different means, for example, that the lengths of the electrodes 20 in the longitudinal axis direction of the shaft 10 are different.

[0046] The conducting wire 30 electrically connects the electrode 20 and an external device (not shown) such as a power supply device of the electrode catheter 1, and is disposed in the lumen of the shaft 10. By connecting the conducting wire 30 to the external device of the electrode catheter 1, the electrode 20 and the external device of the electrode catheter 1 are electrically connected. Although not shown, the electrode catheter 1 has a connector on the proximal side, and the conducting wire 30 is connected to the connector, and the electrode 20 and the external device may be connected by connecting the connector to the external device of the electrode catheter 1.

[0047] Although not shown, the conducting wire 30 has a core and a coating. The material constituting the core of the conducting wire 30 may be any conductive material, and examples thereof include metal materials such as iron, copper, silver, stainless steel, tungsten, nickel, titanium, or alloys thereof. Among these, the material constituting the core of the conducting wire 30 is preferably stainless steel. Since stainless steel has straightness and rigidity, when the material constituting the core of the conducting wire 30 is stainless steel, it is easy to pass the conducting wire 30 through the lumen of the shaft 10 in the manufacture of the electrode catheter 1, and disconnection of the conducting wire 30 is less likely to occur at the connection portion of the electrode 20 or the like.

[0048] The coating of the conducting wire 30 preferably exists in portions other than both ends that are connected to other objects such as the electrode 20. Specifically, for example, by partially removing the coating of the second end 32 portion of the conducting wire 30 and welding this portion to the electrode 20, the second end 32 portion of the conducting wire 30 is connected to the electrode 20. By partially removing the coating of the first end 31 portion of the conducting wire 30 that is connected to an external device of the electrode catheter 1 or the connector of the handle 50, the conducting wire 30 can be configured to have a coating in portions other than both ends.

[0049] The coating of the conducting wire 30 may be any insulating material. For example, 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-based resins such as PTFE, PFA, and ETFE, and synthetic resins such as polyvinyl chloride resins can be mentioned. Among them, the material constituting the coating of the conducting wire 30 is preferably a fluorine-based resin, and more preferably PFA. When the coating of the conducting wire 30 is a fluorine-based resin, the insulation of the conducting wire 30 can be enhanced, and in the inner cavity of the shaft 10, the slidability with respect to other objects such as the conducting wire 30 connected to other electrodes 20 can be improved, and damage to the coating due to contact between the coating of the conducting wire 30 and other objects can be prevented.

[0050] FIG. 3 is a cross-sectional view along the longitudinal axis direction of the shaft 10 in the recess forming step. As shown in FIG. 3, a bottomed recess 11 is formed in the tube wall of the shaft 10. By forming the recess 11 in the tube wall of the shaft 10, it becomes easier to pierce the conducting wire 30 into the shaft 10 in the hole forming step, and it becomes easier to form the hole 13.

[0051] The bottom 12 of the recess 11 may be planar as shown in FIG. 3, or may be curved (not shown). Among them, the bottom 12 of the recess 11 is preferably planar. When the bottom 12 is planar, it becomes easier to form the hole 13 in the bottom 12 of the recess 11 in the hole forming step performed after the recess forming step.

[0052] In the recess forming step, it is preferable to form a plurality of recesses 11 in the tube wall of the shaft 10. By forming a plurality of recesses 11 in the shaft 10, the electrode catheter 1 having a plurality of electrodes 20 can be manufactured.

[0053] Examples of the method for forming the recess 11 in the shaft 10 include cutting with a drill or the like, pressing with a rod-shaped object such as a punch, and hot working by pressing a heated rod-shaped object. In addition to these, for example, after forming a through hole in the shaft 10, a thin film-like object may be covered so as to cover the through hole and fixed to the shaft 10 to form a recess 11 having the thin film-like object as the bottom 12. That is, the bottom 12 of the recess 11 may be present on the outer side of the shaft 10 (not shown) in the tube wall of the shaft 10, or may be present on the inner cavity side of the shaft 10 as shown in FIG. 3. Among the methods for forming the recess 11 in the shaft 10, it is preferable to cut the outer surface of the shaft 10 using a drill or the like to form the recess 11. By forming the recess 11 by cutting the outer surface of the shaft 10, it is easy to form a plurality of recesses 11 having substantially the same depth, size, etc., and the recess forming step can be stably performed.

[0054] FIG. 4 is a cross-sectional view along the longitudinal axis direction of the shaft 10 in the hole forming step, and FIG. 5 is a view seen from a direction perpendicular to the bottom 12 of the recess 11 of the shaft 10 in the hole forming step. As shown in FIGS. 4 and 5, in the hole forming step, the first end 31 of the conducting wire 30 is pierced into the bottom 12 of the recess 11 to form a hole 13 through which the inner cavity and the outside of the shaft 10 communicate. The hole forming step is performed after the recess forming step.

[0055] By piercing the first end 31 of the conducting wire 30 into the bottom 12 of the recess 11 to form the hole 13, the size of the hole 13 becomes close to the outer diameter of the conducting wire 30. As a result, it is possible to manufacture the electrode catheter 1 in which a gap hardly occurs between the conducting wire 30 and the hole 13, and it is difficult for a liquid such as blood to enter the inner cavity of the shaft 10 through this gap. Note that the first end 31 of the conducting wire 30 is preferably the proximal end of the conducting wire 30.

[0056] The extending direction of the hole 13 may be perpendicular to the longitudinal axis direction as shown in FIG. 4, or may be oblique to the longitudinal axis direction although not shown.

[0057] As shown in FIG. 5, in the hole forming step, the place where the first end 31 of the conductive wire 30 is pierced is preferably the central portion of the bottom 12 of the recess 11. The central portion of the bottom 12 of the recess 11 refers to the range within a circle centered on the center point of the bottom 12 of the recess 11 and having a radius of 50% of the longest distance from the center of the bottom 12 to the end of the bottom 12. By piercing the first end 31 of the conductive wire 30 into the central portion of the bottom 12 of the recess 11, it is easy to pierce the first end 31 of the conductive wire 30 into the bottom 12, and it is difficult for a gap to occur between the conductive wire 30 and the hole 13.

[0058] The place where the first end 31 of the conductive wire 30 is pierced in the hole forming step is preferably within the range of a circle centered on the center point of the bottom 12 of the recess 11 and having a radius of 50% of the longest distance from the center of the bottom 12 to the end of the bottom 12, more preferably within the range of a circle having a radius of 30% of the longest distance from the center of the bottom 12 to the end of the bottom 12, and even more preferably within the range of a circle having a radius of 10% of the longest distance from the center of the bottom 12 to the end of the bottom 12. By setting the place where the first end 31 of the conductive wire 30 is pierced within the above range, it is easy to pierce the first end 31 of the conductive wire 30 into the bottom 12 of the recess 11, and it is easy to form the hole 13 in the shaft 10.

[0059] After the hole forming step, it is preferably to have a step of exposing the first end 31 of the conductive wire 30 from the proximal end of the shaft 10. By exposing the first end 31 of the conductive wire 30 from the proximal end of the shaft 10, it is possible to easily attach a member for electrically connecting the conductive wire 30 to an external device such as a power supply device of the electrode catheter 1.

[0060] FIG. 6 is a cross-sectional view along the longitudinal axis direction of the shaft 10 in the conductive wire connection step. As shown in FIG. 6, in the conductive wire connection step, the second end 32 of the conductive wire 30 is connected to the electrode 20. Note that the second end 32 of the conductive wire 30 is preferably the distal end of the conductive wire 30.

[0061] As a method for connecting the conducting wire 30 to the electrode 20, for example, connection by welding, brazing such as soldering, caulking, etc. can be used. Among these, the connection method of the conducting wire 30 to the electrode 20 is preferably welding. Since the conducting wire 30 is connected to the electrode 20 by welding, the connection strength between the conducting wire 30 and the electrode 20 can be increased. Also, although not shown, the conducting wire 30 and the electrode 20 may be connected in a state with a conductive member having conductivity interposed therebetween.

[0062] The connection portion between the conducting wire 30 and the electrode 20 may be coated with a resin or the like so as not to cause oxidative degradation due to moisture or the like contained in the atmosphere or the like. Examples of the resin used for this coating include polyurethane-based resins and epoxy-based resins.

[0063] The conducting wire connection step may be performed before the hole forming step or after the hole forming step. By performing the conducting wire connection step before the hole forming step, it becomes easier to connect the conducting wire 30 to the electrode 20 by welding or the like. By performing the conducting wire connection step after the hole forming step, the conducting wire 30 is easy to handle, and it becomes easier to form the hole 13 by piercing the conducting wire 30 into the shaft 10.

[0064] FIG. 7 is a cross-sectional view along the longitudinal axis direction of the shaft 10 in the electrode arrangement step. As shown in FIG. 7, in the electrode arrangement step, the electrode 20 is arranged outside the hole 13. Note that the electrode arrangement step is preferably performed after the conducting wire connection step.

[0065] The electrode 20 is preferably arranged on the outer surface of the shaft 10. Since the electrode 20 is arranged on the shaft 10, it becomes possible to measure the intracardiac potential by bringing the electrode 20 close to or into contact with the inner wall of the heart, identify the abnormal site of the heart that is the cause of arrhythmia, perform defibrillation in the heart cavity, etc.

[0066] As shown in FIGS. 1 and 2, the electrode catheter 1 may have a tip chip 60 at the distal end of the shaft 10. When the electrode catheter 1 has a tip chip 60 at the distal end of the shaft 10, it may have a tip chip placement step of placing the tip chip 60 at the distal end of the shaft 10.

[0067] Examples of the tip chip 60 include a hemispherical electrode, a lid-like member that prevents the opening at the distal end of the shaft 10, and the like. By having the tip chip 60 at the distal end of the shaft 10, it is possible to prevent a liquid such as blood from entering the lumen of the shaft 10 from the distal end of the shaft 10 when the electrode catheter 1 is used. Further, the tip chip 60 serves as a guide at the tip of the electrode catheter 1, and it is also possible to improve the insertability of the electrode catheter 1.

[0068] As the material constituting the tip chip 60, for example, the material constituting the aforementioned shaft 10, the material constituting the electrode 20, or the like can be used. Note that by forming the tip chip 60 of a conductive material such as the material constituting the electrode 20 and connecting the tip chip 60 to the lead wire 30, the tip chip 60 can also serve as the electrode 20.

[0069] As shown in FIG. 2, when the electrode catheter 1 has a tip chip 60 at the distal end of the shaft 10, the tip chip 60 has a tip chip connection member 61 connected to the tip chip 60, and the tip chip connection member 61 is preferably disposed in the lumen of the shaft 10. Examples of the tip chip connection member 61 include a pull wire for bending the distal side of the shaft 10 and a lead wire 30 for the tip chip 60 to function as the electrode 20.

[0070] When the tip chip 60 has the tip chip connection member 61, the connection member connection step of connecting the tip chip connection member 61 to the tip chip 60 may be performed after the tip chip placement step, but it is preferably performed before the tip chip placement step. By performing the connection member connection step before the tip chip placement step, it becomes easier to connect the tip chip connection member 61 to the tip chip 60, and it is easier to securely fix the tip chip connection member 61 to the tip chip 60.

[0071] Although not shown, the electrode catheter 1 may not have the tip chip 60 at the distal end of the shaft 10. When the electrode catheter 1 does not have the tip chip 60, it is preferable to have a step of closing the opening at the distal end of the shaft 10 by heat-sealing or the like the distal end portion of the shaft 10.

[0072] As shown in FIG. 5, it is preferable that the area of the bottom 12 of the recess 11 is larger than the area of the hole 13 in a cross-section perpendicular to the depth direction of the hole 13. By the area of the bottom 12 of the recess 11 being larger than the area of the hole 13, it becomes easier to pierce the first end 31 of the conducting wire 30 into the bottom 12 to form the hole 13.

[0073] The area of the bottom 12 of the recess 11 is preferably more than 1.0 times, more preferably 1.1 times or more, still more preferably 1.3 times or more, and even more preferably 1.5 times or more the area of the hole 13 in a cross-section perpendicular to the depth direction of the hole 13. By setting the lower limit value of the ratio of the area of the bottom 12 of the recess 11 to the area of the hole 13 within the above range, the size of the bottom 12 of the recess 11 can be sufficiently ensured. Therefore, it becomes possible to easily pierce the first end 31 of the conducting wire 30 into the bottom 12 of the recess 11. Also, the area of the bottom 12 of the recess 11 is preferably 10 times or less, more preferably 9 times or less, and still more preferably 8 times or less the area of the hole 13 in a cross-section perpendicular to the depth direction of the hole 13. By setting the upper limit value of the ratio of the area of the bottom 12 of the recess 11 to the area of the hole 13 within the above range, it becomes difficult for the size of the hole 13 to increase. As a result, when the electrode 20 is disposed outside the hole 13, it becomes possible to easily cover the entire hole 13 with the electrode 20.

[0074] As shown in FIG. 3, after the recess forming step, the depth D1 of the recess 11 is preferably longer than the shortest distance D2 from the bottom 12 of the recess 11 to the inner surface of the shaft 10. Since the depth D1 of the recess 11 is longer than the shortest distance D2 from the bottom 12 of the recess 11 to the inner surface of the shaft 10, it becomes easier to pierce the first end 31 of the conducting wire 30 into the bottom 12 of the recess 11, and it becomes easier to form the hole 13.

[0075] After the recess forming step, the depth D1 of the recess 11 is preferably 1.1 times or more, more preferably 1.5 times or more, and even more preferably 2.0 times or more the shortest distance D2 from the bottom 12 of the recess 11 to the inner surface of the shaft 10. By setting the lower limit value of the ratio of the depth D1 of the recess 11 to the shortest distance D2 from the bottom 12 of the recess 11 to the inner surface of the shaft 10 within the above range, the thickness of the bottom 12 of the recess 11 can be made thinner, and it becomes easier to pierce the conductive wire 30 to form the hole 13. Further, the depth D1 of the recess 11 is preferably 7 times or less, more preferably 6 times or less, and even more preferably 5 times or less the shortest distance D2 from the bottom 12 of the recess 11 to the inner surface of the shaft 10. By setting the upper limit value of the ratio of the depth D1 of the recess 11 to the shortest distance D2 from the bottom 12 of the recess 11 to the inner surface of the shaft 10 within the above range, while making it easier to pierce the first end 31 of the conductive wire 30, strength can be imparted to the bottom 12 of the recess 11. As a result, when the conductive wire 30 is inserted into the inner cavity of the shaft 10, even if the conductive wire 30 is pulled and a load is applied to the hole 13, the hole 13 is less likely to tear, and it is possible to prevent a gap from forming between the hole 13 and the conductive wire 30.

[0076] As shown in FIG. 7, the length L1 of the bottom 12 of the recess 11 in the longitudinal axis direction of the shaft 10 is preferably shorter than the length L2 of the electrode 20 in the longitudinal axis direction of the shaft 10. Since the length L1 of the bottom 12 of the recess 11 is shorter than the length L2 of the electrode 20, when the electrode 20 is disposed outside the hole 13, the entire bottom 12 of the recess 11 can be covered by the electrode 20. Therefore, a gap is less likely to occur between the inner surface of the electrode 20 and the bottom 12 of the recess 11, and it is possible to make it difficult for a liquid such as blood to penetrate from this gap.

[0077] The length L1 of the bottom 12 of the recess 11 in the longitudinal axis direction of the shaft 10 is preferably 70% or less, more preferably 50% or less, and even more preferably 30% or less of the length L2 of the electrode 20 in the longitudinal axis direction of the shaft 10. By setting the upper limit value of the ratio of the length L1 of the bottom 12 of the recess 11 to the length L2 of the electrode 20 within the above range, after arranging the electrode 20 outside the hole 13, the bottom 12 of the recess 11 is less likely to be exposed from the electrode 20, and it becomes difficult for a liquid such as blood to enter the bottom 12 of the recess 11. Note that the lower limit value of the ratio of the length L1 of the bottom 12 of the recess 11 to the length L2 of the electrode 20 is not particularly limited, but for example, it can be 1% or more, 2% or more, or 3% or more.

[0078] As shown in FIG. 5, it is preferable that the area of the bottom 12 of the recess 11 is larger than the cross-sectional area perpendicular to the longitudinal axis direction of the conducting wire 30. When the area of the bottom 12 of the recess 11 is larger than the cross-sectional area of the conducting wire 30, it becomes easier to form the hole 13 by piercing the first end 31 of the conducting wire 30 into the bottom 12.

[0079] The area of the bottom 12 of the recess 11 is preferably 1.1 times or more, more preferably 1.3 times or more, and even more preferably 1.5 times or more of the cross-sectional area perpendicular to the longitudinal axis direction of the conducting wire 30. By setting the lower limit value of the ratio of the area of the bottom 12 of the recess 11 to the cross-sectional area of the conducting wire 30 within the above range, it becomes easier to pierce the first end 31 of the conducting wire 30 into the bottom 12 of the recess 11. Also, the area of the bottom 12 of the recess 11 is preferably 10 times or less, more preferably 9 times or less, and even more preferably 8 times or less of the cross-sectional area perpendicular to the longitudinal axis direction of the conducting wire 30. By setting the upper limit value of the ratio of the area of the bottom 12 of the recess 11 to the cross-sectional area of the conducting wire 30 within the above range, the size of the hole 13 formed by piercing the conducting wire 30 into the bottom 12 is less likely to increase, and when the electrode 20 is arranged outside the hole 13, the entire hole 13 can be covered by the electrode 20.

[0080] As shown in FIG. 7, after the electrode arrangement step, it is preferable that the second end 32 of the conducting wire 30 is located outside the shaft 10. That the second end 32 of the conducting wire 30 is located outside the shaft 10 can be paraphrased as that the second end 32 of the conducting wire 30 is not located in the inner cavity of the shaft 10. Since the second end 32 of the conducting wire 30 is located outside the shaft 10, the surface area of the conducting wire 30 inserted through the tube wall of the shaft 10 can be reduced. As a result, the number of holes 13 for inserting the conducting wire 30 into the inner cavity of the shaft 10 can be reduced, or the size of the holes 13 can be reduced, and the path for a liquid such as blood to penetrate into the inner cavity of the shaft 10 can also be reduced. Further, for example, if the connection between the conducting wire 30 and the electrode 20 is made by welding, and when the distance between the welding portion of the conducting wire 30 and the electrode 20 and the second end 32 of the conducting wire 30 is close, since the second end 32 of the conducting wire 30 is located outside the shaft 10, the distance between the welding portion of the conducting wire 30 and the electrode 20 and the hole 13 can be increased, and it can be prevented that the welding portion of the conducting wire 30 and the electrode 20 expands the hole 13 to generate a gap.

[0081] Although not shown, after the hole forming step, it is preferable to have a conducting wire adhesion step of fixing the conducting wire 30 to the hole 13 with an adhesive. By fixing the conducting wire 30 to the hole 13 using an adhesive, an adhesive will exist between the hole 13 and the conducting wire 30, and it becomes more difficult for a gap to further occur between the hole 13 and the conducting wire 30. Further, since the conducting wire 30 is firmly fixed to the hole 13 by the adhesive, for example, when the shaft 10 of the electrode catheter 1 bends and the conducting wire 30 is pulled, or when a load is applied to the conducting wire 30, it is possible to prevent the load from being applied to the hole 13 by the conducting wire 30 and the hole 13 from tearing.

[0082] As the adhesive for adhesively fixing the conducting wire 30 to the hole 13, it is preferable to use a polyurethane-based, epoxy-based, cyano-based, fluorine-based, or silicone-based adhesive.

[0083] Next, the electrode catheter of the present invention will be described. In the following description, parts overlapping with the above description will be omitted from the description.

[0084] As shown in FIGS. 1 and 2, the electrode catheter 1 includes a shaft 10 that extends in the longitudinal axis direction and has a lumen, and has a hole 13 through which the lumen and the outer surface communicate, an electrode 20 disposed outside the hole 13, and a conducting wire 30 connected to the electrode 20 and extending into the lumen of the shaft 10 through the hole 13. The shaft 10 has a bottomed recess 11 in the tube wall of the shaft 10, the hole 13 is provided at the bottom 12 of the recess 11, the bottom 12 of the recess 11 is circular, and the area of the bottom 12 of the recess 11 is smaller than the area of the inner surface of the electrode 20.

[0085] As shown in FIG. 5, the bottom 12 of the recess 11 is circular. That is, the shape of the bottom 12 as viewed from a direction perpendicular to the bottom 12 of the recess 11 is circular. Note that the circular shape includes a perfect circle, an ellipse, an oblong, and an oval.

[0086] Since the shaft 10 has a bottomed recess 11 and the hole 13 is provided at the bottom 12, it is difficult for the outer surface of the shaft 10 to come into contact with the connection portion between the conducting wire 30 inserted through the hole 13 and the electrode 20. As a result, it is possible to prevent a gap from easily occurring between the electrode 20 and the outer surface of the shaft 10 due to the shaft 10 being partially distorted when the connection portion between the conducting wire 30 and the electrode 20 is pressed against the shaft 10. Further, by preventing the distortion of the shaft 10, it is also possible to prevent the lumen of the shaft 10 from collapsing. By preventing the lumen of the shaft 10 from collapsing, when arranging internal structures such as the conducting wire 30 in the lumen of the shaft 10 during the manufacture of the electrode catheter 1, it is possible to secure a space for arranging the internal structures and make it easier to arrange the internal structures, and to exert an effect of making the internal structures arranged in the lumen of the shaft 10 less likely to be damaged.

[0087] Since the bottom 12 of the recess 11 is circular, it is easy to form the bottomed recess 11 in the shaft 10, and without making the size of the bottom 12 too large, it is possible to make it difficult for the connection portion between the conducting wire 30 and the electrode 20 to contact the outer surface of the shaft 10. Specifically, as shown in FIGS. 2 and 7, since the connection portion between the conducting wire 30 and the electrode 20 is accommodated in the recess 11, it becomes difficult for the connection portion between the conducting wire 30 and the electrode 20 to contact the outer surface of the shaft 10. For example, when connecting the conducting wire 30 to the electrode 20 by welding or the like, even if the connection portion between the conducting wire 30 and the electrode 20 deviates from the target position, the connection portion between the conducting wire 30 and the electrode 20 is likely to be accommodated in the recess 11.

[0088] Since the area of the bottom 12 of the recess 11 is smaller than the area of the inner surface of the electrode 20, the electrode 20 can cover the entire bottom 12 of the recess 11. As a result, it becomes difficult for a gap to occur between the inner side surface of the electrode 20 and the bottom 12 of the recess 11, and it is possible to prevent a liquid such as blood from entering through this gap.

[0089] When the electrode 20 is a ring-shaped electrode, it is preferable that the inner diameter of the electrode 20 is smaller than the outer diameter of the shaft 10. Since the inner diameter of the electrode 20 is smaller than the outer diameter of the shaft 10, it becomes difficult for the end portion of the electrode 20 to be caught by other objects, and it is possible to make it difficult to damage the inner wall of a blood vessel or the heart. To make the inner diameter of the electrode 20 smaller than the outer diameter of the shaft 10, for example, a method of forming the inner diameter of the electrode 20 larger than the outer diameter of the shaft 10, passing the electrode 20 through the shaft 10, and caulking the electrode 20 from the outside to reduce the inner diameter of the electrode 20, or a method of forming the shaft 10 having an outer diameter smaller than the inner diameter of the electrode 20 with a heat-expandable resin, passing the electrode 20 through the shaft 10, and heating the shaft 10 to increase the outer diameter of the shaft 10 can be mentioned.

[0090] As shown in FIG. 1, the electrode catheter 1 may have a handle 50 on the proximal side. Since the electrode catheter 1 has the handle 50, the operation of the electrode catheter 1 becomes easier.

[0091] As shown in FIG. 2, in the portion of the hole 13 in the inner cavity of the shaft 10, it is preferable that the inner wall of the shaft 10 protrudes toward the center side of the longitudinal axis of the shaft 10. That is, in the inner cavity of the shaft 10, it is preferable that the inner wall of the shaft 10 in the portion of the hole 13 is convex inward of the shaft 10. When the distal side of the shaft 10 of the electrode catheter 1 is bent or the like and the conducting wire 30 is pulled, the conducting wire 30 contacts this protruding portion and a load is applied prior to the outer side of the shaft 10 of the hole 13 in the portion of the hole 13 in the inner cavity of the shaft 10. As a result, deformation of the hole 13 by the conducting wire 30 hardly occurs on the outer side of the shaft 10, a gap hardly occurs between the hole 13 and the conducting wire 30, and it is possible to make it difficult for a liquid such as blood to enter the inner cavity of the shaft 10. That is, when the conducting wire 30 is pulled, since the conducting wire 30 contacts the protruding portion prior to the hole 13, deformation of the hole 13 hardly occurs and a gap hardly occurs between the hole 13 and the conducting wire 30, and as a result, it becomes difficult for a liquid such as blood to enter the inner cavity of the shaft 10.

[0092] As described above, the method for manufacturing an electrode catheter of the present invention includes a preparation step of preparing a shaft extending in the longitudinal axis direction and having an inner cavity, an electrode, and a conducting wire; a recess forming step of forming a bottomed recess in the tube wall of the shaft; a hole forming step of piercing the first end of the conducting wire into the bottom of the recess to form a hole through which the inner cavity and the outside communicate in the shaft; a conducting wire connecting step of connecting the second end of the conducting wire to the electrode; and an electrode arranging step of arranging the electrode outside the hole. By having such steps in the method for manufacturing an electrode catheter of the present invention, it is possible to easily manufacture an electrode catheter in which a gap hardly occurs between the conducting wire and the hole and it is difficult for a liquid such as blood to enter the inner cavity of the shaft.

[0093] In addition, the electrode catheter of the present invention includes a shaft that extends in the longitudinal axis direction, has a lumen, and has a hole through which the lumen and the outer surface communicate, an electrode disposed outside the hole, and a conducting wire connected to the electrode and extending into the lumen of the shaft through the hole. The shaft has a bottomed recess in the tube wall of the shaft, the hole is provided at the bottom of the recess, the bottom of the recess is circular, and the area of the bottom of the recess is smaller than the area of the inner surface of the electrode. With such a configuration of the electrode catheter of the present invention, a gap is less likely to occur between the conducting wire and the hole, and it is possible to prevent a liquid such as blood from entering the lumen of the shaft.

Explanation of Reference Numerals

[0094] 1: Electrode catheter 10: Shaft 11: Recess 12: Bottom 13: Hole 20: Electrode 30: Conducting wire 31: First end 32: Second end 50: Handle 60: Tip 61: Tip connection member D1: Depth of recess D2: Shortest distance from the bottom of the recess to the inner surface of the shaft L1: Length of the bottom of the recess L2: Length of the electrode

Claims

1. A preparation step of preparing a shaft extending in the longitudinal axis direction and having a lumen, an electrode, and a conducting wire; A recess forming step of forming a bottomed recess in the tube wall of the shaft; A hole forming step of piercing a first end of the conducting wire into the bottom of the recess to form a hole through which the lumen and the outside of the shaft communicate; A conducting wire connection step of connecting a second end of the conducting wire to the electrode; An electrode arrangement step of arranging the electrode outside the hole, the manufacturing method of an electrode catheter having the above steps.

2. The manufacturing method of the electrode catheter according to Claim 1, wherein an area of the bottom of the recess is larger than an area of the hole in a cross section perpendicular to a depth direction of the hole.

3. The manufacturing method of the electrode catheter according to Claim 1 or 2, wherein after the recess forming step, a depth of the recess is longer than a shortest distance from the bottom of the recess to an inner surface of the shaft.

4. The manufacturing method of the electrode catheter according to any one of Claims 1 to 3, wherein a length of the bottom of the recess in a longitudinal axis direction of the shaft is shorter than a length of the electrode in a longitudinal axis direction of the shaft.

5. The manufacturing method of the electrode catheter according to any one of Claims 1 to 4, wherein an area of the bottom of the recess is larger than a cross-sectional area perpendicular to a longitudinal axis direction of the conducting wire.

6. The manufacturing method of the electrode catheter according to any one of Claims 1 to 5, wherein after the electrode arrangement step, the second end of the conducting wire is located outside the shaft.

7. The manufacturing method of the electrode catheter according to any one of Claims 1 to 6, further comprising a conducting wire adhesion step of fixing the conducting wire to the hole with an adhesive after the hole forming step.

8. A shaft extending in the longitudinal axis direction, having a lumen, and having a hole through which the lumen and an outer surface communicate; An electrode arranged outside the hole; A conducting wire connected to the electrode and extending into the lumen of the shaft through the hole, the electrode catheter having the above components, wherein the shaft has a bottomed recess in a tube wall of the shaft, the hole is provided at the bottom of the recess, the bottom of the recess is circular, and an area of the bottom of the recess is smaller than an area of an inner surface of the electrode.

9. The electrode catheter according to Claim 8, wherein an area of the bottom of the recess is larger than an area of the hole in a cross section perpendicular to a depth direction of the hole.

10. The electrode catheter according to claim 8 or 9, wherein the depth of the recess is longer than the shortest distance from the bottom of the recess to the inner surface of the shaft.

11. The electrode catheter according to any one of claims 8 to 10, wherein the length of the bottom of the recess in the longitudinal axis direction of the shaft is shorter than the length of the electrode in the longitudinal axis direction of the shaft.

12. The electrode catheter according to any one of claims 8 to 11, wherein the area of the bottom of the recess is larger than the cross-sectional area perpendicular to the longitudinal axis direction of the wire.

13. The electrode catheter according to any one of claims 8 to 12, wherein the second end of the wire is located outside the shaft.

14. The electrode catheter according to any one of claims 8 to 13, wherein, in the portion of the hole in the lumen of the shaft, the inner wall of the shaft protrudes toward the center of the longitudinal axis of the shaft.

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