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 an electrode catheter 1 comprising: a shaft 10 which extends in a longitudinal axis direction, has a lumen, and has a slit 40 in which a lumen communicates with an external surface; an electrode 20 arranged on outside of the slit 40; and a conductor wire 30 connected to the electrode 20, and extending into the lumen of the shaft 10 through the slit 40. The slit 40 comprises: a conductor wire existence area 41 in which the conductor wire 30 exists; and a conductor wire non-existence area 42 in which no conductor wire 30 exists, and a width W2 of the slit 40 on the conductor wire non-existence area 42 is smaller than a width W1 of the slit 40 on the conductor wire existence area 41 in the electrode catheter.SELECTED DRAWING: Figure 3

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] An electrode catheter is mainly used as a medical device for diagnosing arrhythmia by measuring the potential of the heart and for cauterizing internal tissues by passing a high-frequency current to treat arrhythmia. 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 meter. A connector is used for connecting the conducting wire and the electrocardiograph meter. For example, by inserting the electrode catheter into a patient's heart and connecting the connector to the electrocardiograph meter, it is possible to measure the electrocardiogram near the ring-shaped electrode portion and accurately grasp the state of the myocardium that causes arrhythmia.

[0003] When a liquid such as blood enters the gap between the electrode and the shaft and flows into the lumen of the shaft from the wire hole, a short circuit may occur between the plurality of conducting wires, or corrosion of the conducting wires and the internal structures of the electrode catheter may occur, which may cause the failure of the electrode catheter. 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 failure 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 enters the lumen of a shaft, for example, Patent Document 1 discloses an electrode catheter comprising a catheter body, a control handle, a catheter tip portion, 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 portion 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 portion from the side holes, extends through the lumen of the catheter tip portion, the lumen of the catheter body, and the inner hole of the control handle, and an insulating resin thin film is formed on at least the surface of the metal core wire at the tip portion of the lead wire and 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, wherein the outer surface of the ring-shaped electrode is located inside the outer surface of the resin tube in a portion 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, and 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 major 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 fixing 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, 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 front end 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, the ring-shaped electrode and lead wire are attached to the resin tube by thermally expanding the resin tube, but it can be difficult to precisely adjust the expansion of the resin tube, and there is room for improvement in terms of making manufacturing easier.

[0011] In the electrode catheter of Patent Document 3, when manufacturing the electrode catheter, it can be difficult to form an opening in the cylindrical body whose opening area decreases toward the axis of the cylindrical body, or to manufacture a conductive member having a cone-shaped portion that tapers toward the axis of the cylindrical body.

[0012] The electrode catheter of Patent Document 4 is provided with sealant on both the front and rear side surfaces of the electrode, in the gap between the electrode and the outer surface of the first tube body, and in the gap between the inside of the electrode and the lead wire in the side hole of the first tube body, but it is difficult to provide sealant without leaving any gaps, making it difficult to manufacture.

[0013] The present invention has been made in consideration of the above circumstances, and its object is to provide an electrode catheter in which gaps are less likely to occur between the conductor hole formed in the shaft and the conductor, and which is easy to manufacture, and a method for manufacturing the electrode catheter. [Means for solving the problem]

[0014] The electrode catheter that can solve the above problem comprises a shaft that extends in the longitudinal direction, has an inner lumen, and has a slit that connects the inner lumen to the outer surface, an electrode that is positioned outside the slit, and a conductor that is connected to the electrode and extends into the inner lumen of the shaft through the slit, the slit having a conductor-present region where the conductor is present inside and a conductor-absent region where the conductor is not present inside, and the width of the slit in the conductor-absent region is smaller than the width of the slit in the conductor-present region.

[0015] In the electrode catheter of the present invention, the angle formed by the extending direction of the slit as viewed from the upper surface of the slit and the longitudinal axis direction of the shaft is preferably 10 degrees or less (including 0 degrees).

[0016] In the electrode catheter of the present invention, the slit has a proximal region that is located on the proximal side and is a region that bisects the length of the shaft in the longitudinal axis direction of the shaft, and it is preferable that the conducting wire is arranged in the proximal region.

[0017] In the electrode catheter of the present invention, the slit has a most proximal region that is located on the most proximal side and is a region that trisects the length of the shaft in the longitudinal axis direction of the shaft, and it is preferable that the conducting wire is arranged in the most proximal region.

[0018] In the electrode catheter of the present invention, it is preferable that the second end of the conducting wire is arranged outside the shaft.

[0019] In the electrode catheter of the present invention, it is preferable that the length of the slit in the longitudinal axis direction of the shaft is shorter than the length of the electrode in the longitudinal axis direction of the shaft.

[0020] In the electrode catheter of the present invention, it is preferable that the area of the slit in a cross-section perpendicular to the depth direction of the slit is smaller than the cross-sectional area perpendicular to the longitudinal axis direction of the conducting wire.

[0021] In the electrode catheter of the present invention, it is preferable that the length of the slit in the longitudinal axis direction of the shaft is longer than the length of the slit in the circumferential direction of the shaft.

[0022] A manufacturing method for an electrode catheter that can solve the above problem includes a preparation step of preparing a shaft extending in the longitudinal direction and having an inner lumen, an electrode, and a conductor; a slit forming step of forming a slit in the shaft that connects the inner lumen to the outer surface of the shaft and has a width smaller than the diameter of the conductor; a conductor insertion step of inserting a first end of the conductor into the slit; a conductor connection step of connecting a second end of the conductor to the electrode; and an electrode placement step of placing the electrode outside the slit.

[0023] In the method for manufacturing an electrode catheter of the present invention, it is preferable to have a core material placement step of placing a core material in the lumen of the shaft before the slit formation step.

[0024] In the method for producing an electrode catheter of the present invention, the angle formed between the extending direction of the slit as viewed from above and the longitudinal axis direction of the shaft is preferably 10 degrees or less (including 0 degrees).

[0025] In the method for manufacturing an electrode catheter of the present invention, the slit has a proximal region that is an area that divides the length of the shaft in the longitudinal axis direction into two equal parts and is located on the proximal side, and it is preferable that after the slit forming process, a conductor placement process be included in which a conductor is placed in the proximal region.

[0026] In the manufacturing method of the electrode catheter of the present invention, it is preferable that the slit has a proximal-most region that is located on the most proximal side among regions that divide the length of the shaft in the longitudinal axis direction into three equal parts, and that the slit forming process is followed by a conductor placement process in which a conductor is placed in the proximal-most region.

[0027] In the method for manufacturing an electrode catheter of the present invention, it is preferable that the second end of the conductive wire is located outside the shaft after the electrode placement step.

[0028] In the method for producing an electrode catheter of the present invention, it is preferable to have a lead wire bonding step of fixing a lead wire to the slit with an adhesive after the slit forming step. [Effects of the Invention]

[0029] The electrode catheter of the present invention has a shaft with a slit that connects the inner lumen to the outer surface, and the slit has a conductor-present region where a conductor is present and a conductor-free region where no conductor is present, and the width of the slit in the conductor-free region is smaller than the width of the slit in the conductor-present region, making it less likely for a gap to form between the conductor and the slit, thereby making it more difficult for liquids such as blood to enter the inner lumen of the shaft.

[0030] Furthermore, the method for manufacturing an electrode catheter of the present invention includes a slit forming step for forming a slit in the shaft that connects the inner cavity with the outer surface of the shaft and has a width smaller than the diameter of the conductor wire, thereby making it difficult for a gap to form between the conductor wire and the slit, thereby making it possible to easily manufacture an electrode catheter that is less susceptible to the infiltration of liquids such as blood into the inner cavity of the shaft. [Brief explanation of the drawings]

[0031]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

[0032] 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 differ from the actual dimensions because priority is given to facilitating the understanding of the features of the present invention.

[0033] FIG. 1 is an overall view of the electrode catheter 1 in one embodiment of the present invention, FIG. 2 is a cross-sectional view along the longitudinal axis direction of the distal end portion of the electrode catheter 1, and FIG. 3 is a view seen from above the slit 40 of the electrode catheter 1. In FIG. 3, for the explanation of the slit 40, part of the illustration of the electrode 20 is omitted.

[0034] 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 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 described 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 to 3, the right side of the figure is the proximal side, and the left side of the figure is the distal side.

[0035] First, the electrode catheter 1 will be described.

[0036] The electrode catheter 1 is, for example, inserted from its distal side through the blood vessel of a patient to reach the heart, and is used for the examination, treatment, defibrillation, etc. of arrhythmia in the heart.

[0037] As shown in FIGS. 1 to 3, the electrode catheter 1 includes a shaft 10 that extends in the longitudinal axis direction, has a lumen, and has a slit 40 through which the lumen and the outer surface communicate, an electrode 20 disposed outside the slit 40, and a conducting wire 30 connected to the electrode 20 and extending into the lumen of the shaft 10 through the slit 40.

[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 of the shaft 10 is one, since there is no partition wall or the like inside the shaft 10 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 of the shaft 10 is plural, by arranging a plurality of conducting wires 30 and the like disposed in the lumens in separate lumens respectively, it is possible to prevent the conducting wire 30 from contacting another conducting wire 30 or the like, and to prevent damage such as disconnection of the conducting wire 30.

[0039] Examples of the material of the shaft 10 include synthetic resins such as 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 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 can have good insertability into blood vessels.

[0040] The length of the shaft 10 in the longitudinal axis direction can be selected to be appropriate for 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. Also, 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 increased, and the electrode catheter 1 with good insertability into blood vessels can be obtained. Also, 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 may be a flat-plate electrode having a shape such as a rectangle or a square. When the electrode 20 is a flat-plate electrode, at least one of the back surface (inner surface) and the front surface (outer surface) of the flat-plate electrode may be a curved surface so as to easily follow the curved surface of the surface of the shaft 10. Among them, it is preferable that the electrode 20 is ring-shaped. Since 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 them, the material constituting the electrode 20 is preferably platinum or an alloy thereof. Since the electrode 20 is configured 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 electrode 20 is preferably disposed on the outer surface of the shaft 10. Since the electrode 20 is disposed on the shaft 10, it is possible to measure the intracardiac potential by bringing the electrode 20 close to or into contact with the inner wall of the heart, identify an abnormal site of the heart that causes arrhythmia, perform defibrillation in the heart cavity, and the like.

[0046] 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.

[0047] The lead 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. The lead wire 30 has a first end 31 and a second end 32. By connecting the lead 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 lead wire 30 is connected to the connector. By connecting the connector to the external device of the electrode catheter 1, the electrode 20 and the external device may be connected. It is preferable that the first end 31 of the lead wire 30 is the proximal end of the lead wire 30, and the second end 32 is the distal end of the lead wire 30.

[0048] Although not shown, the lead wire 30 has a core and a coating. The material constituting the core of the lead wire 30 may be any conductive material. For example, metal materials such as iron, copper, silver, stainless steel, tungsten, nickel, titanium, or alloys thereof can be mentioned. Among them, it is preferable that the material constituting the core of the lead wire 30 is stainless steel. Since stainless steel has straightness and rigidity, when the material constituting the core of the lead wire 30 is stainless steel, it is easy to pass the lead wire 30 through the lumen of the shaft 10 during the manufacture of the electrode catheter 1, and it is less likely that the lead wire 30 breaks at the connection part of the electrode 20 or the like.

[0049] The coating of the lead wire 30 preferably exists in the portion other than both ends 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 lead wire 30 and welding this portion to the electrode 20, the second end 32 portion of the lead wire 30 is connected to the electrode 20. By partially removing the coating of the first end 31 portion of the lead wire 30 connected to the external device of the electrode catheter 1 or the connector of the handle 50, the lead wire 30 can be configured to have a coating in the portion other than both ends.

[0050] 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. 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 the slidability with respect to other objects such as the conducting wire 30 connected to the other electrode 20 in the inner cavity of the shaft 10 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.

[0051] As a method for connecting the conducting wire 30 to the electrode 20, for example, welding, brazing such as soldering, and connection by caulking can be used. Among them, the connection method of the conducting wire 30 to the electrode 20 is preferably welding. When 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 enhanced. Further, although not shown, the conducting wire 30 and the electrode 20 may be connected in a state where a conductive member having conductivity is interposed between the conducting wire 30 and the electrode 20.

[0052] The connection portion between the conducting wire 30 and the electrode 20 may be coated with a resin or the like so as to prevent 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 resins and epoxy resins.

[0053] To configure the shaft 10 to have a slit 40 that connects the inner cavity and outer surface of the shaft 10, for example, cutting the tubular wall of the shaft 10 with a bladed tool such as a knife or cutter, or removing a portion of the tubular wall of the shaft 10 with a drill or punch to create an elongated hole in the tubular wall of the shaft 10 whose width is small relative to its length, etc. Among these, it is preferable to form the slit 40 by cutting the shaft 10 with a bladed tool. Forming the slit 40 by cutting the shaft 10 makes it easy to manufacture a shaft 10 with a slit 40.

[0054] As shown in Figure 3, the slit 40 has a conductor presence region 41 where the conductor 30 is present inside and a conductor non-presence region 42 where the conductor 30 is not present inside, and the width W2 of the slit 40 in the conductor non-presence region 42 is smaller than the width W1 of the slit 40 in the conductor presence region 41.

[0055] Because the conductor 30 is present inside the conductor wire present region 41, the width W1 of the slit 40 is close to the diameter (outer diameter) of the conductor wire 30. That is, in the conductor wire present region 41, the width of the slit 40 is widened by the conductor wire 30. On the other hand, in the conductor wire non-presence region 42, the conductor wire 30 is not present inside, and the width W2 of the slit 40 remains the same. As a result, the width W2 of the slit 40 in the conductor wire non-presence region 42 is smaller than the width W1 of the slit 40 in the conductor wire present region 41.

[0056] Since the width W2 of the slit 40 in the conductor-free region 42 is smaller than the width W1 of the slit 40 in the conductor-present region 41, a gap is less likely to occur between the conductor 30 and the slit 40. This makes it possible to provide an electrode catheter 1 that is less susceptible to fluids such as blood penetrating into the lumen of the shaft 10 from between the conductor 30 and the slit 40.

[0057] It is preferable that one slit 40 has one conductor wire presence region 41. In other words, it is preferable that one conductor wire 30 is inserted into one slit 40, and that the conductor wire 30 passes through the slit 40 only once. By having one conductor wire presence region 41 in one slit 40, gaps are less likely to occur between the conductor wire 30 and the slit 40, making it more difficult for liquids such as blood to penetrate into the lumen of the shaft 10. It is to be noted that one slit 40 may have one or more conductor wire absence regions 42.

[0058] It is preferable that there is a portion where the end faces of the slits 40 are in contact with each other in the conductor free region 42. By having the end faces of the slits 40 in contact with each other in the conductor free region 42, it is possible to reduce gaps in the conductor free region 42, making it difficult for liquids such as blood to enter the lumen of the shaft 10.

[0059] In order to form the portion in the conductor-free region 42 where the end faces of the slits 40 are in contact with each other, the slits 40 may be formed by, for example, making cuts in the tube wall of the shaft 10 with a blade.

[0060] The number of slits 40 in the shaft 10 may be one, but preferably multiple. When the shaft 10 has multiple slits 40, the electrode catheter 1 can have multiple electrodes 20. When the shaft 10 has multiple slits 40, the lengths, widths, and extension directions of the slits 40 may be the same or different.

[0061] The extending direction of the slit 40 as viewed from above may be curved, wavy, zigzag, or the like, but is preferably linear as shown in Fig. 3. By having the extending direction of the slit 40 be linear, it becomes easier to form the slit 40 in the shaft 10, and also gaps are less likely to occur between the slit 40 and the conductive wire 30.

[0062] When the electrode 20 is a ring-shaped electrode, the inner diameter of the electrode 20 is preferably 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, the end portion of the electrode 20 is less likely to be caught by other objects, and it is possible to prevent damage to blood vessels, the inner wall of the heart, etc. To make the inner diameter of the electrode 20 smaller than the outer diameter of the shaft 10, for example, the inner diameter of the electrode 20 is formed larger than the outer diameter of the shaft 10, the electrode 20 is passed through the shaft 10, and the electrode 20 is caulked from the outside to reduce the inner diameter of the electrode 20, or a shaft 10 with an outer diameter smaller than the inner diameter of the electrode 20 is formed of a thermally expandable resin, the electrode 20 is passed through the shaft 10, the shaft 10 is heated, and the outer diameter of the shaft 10 is increased, etc.

[0063] 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.

[0064] As shown in FIGS. 1 and 2, the electrode catheter 1 may have a tip 60 at the distal end of the shaft 10.

[0065] Examples of the tip 60 include a hemispherical electrode, a lid-like member that prevents the opening at the distal end of the shaft 10, etc. Since the tip 60 is provided 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 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.

[0066] As the material constituting the tip 60, for example, the material constituting the aforementioned shaft 10, or the material constituting the electrode 20, etc. can be used. In addition, by forming the tip 60 of a conductive material such as the material constituting the electrode 20 and connecting the tip 60 to the lead wire 30, it is also possible for the tip 60 to also serve as the electrode 20.

[0067] As shown in FIG. 2, when the electrode catheter 1 has the tip chip 60 at the distal end of the shaft 10, the tip chip 60 has a tip chip connecting member 61 connected to the tip chip 60, and the tip chip connecting member 61 is preferably disposed in the lumen of the shaft 10. Examples of the tip chip connecting member 61 include a pull wire for bending the distal side of the shaft 10 and a conducting wire 30 for the tip chip 60 to function as the electrode 20.

[0068] 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 that the opening at the distal end of the shaft 10 is closed by heat-sealing or the like at the distal end portion of the shaft 10.

[0069] As shown in FIG. 3, the angle θ1 formed by the extending direction of the slit 40 as viewed from the upper surface of the slit 40 and the longitudinal axis direction of the shaft 10 is preferably 10 degrees or less (including 0 degree). When the angle θ1 formed by the extending direction of the slit 40 and the longitudinal axis direction of the shaft 10 is 10 degrees or less (including 0 degree), when the distal side of the shaft 10 of the electrode catheter 1 is bent, the end faces of the slit 40 are less likely to open. Therefore, even when the shaft 10 is in a bent state, a gap is less likely to occur in the slit 40, and it is possible to make it difficult for a liquid such as blood to enter the lumen of the shaft 10 through the gap of the slit 40.

[0070] The angle θ1 formed by the extending direction of the slit 40 as viewed from the upper surface of the slit 40 and the longitudinal axis direction of the shaft 10 is preferably 10 degrees or less, more preferably 5 degrees or less, even more preferably 3 degrees or less, and still more preferably 0 degrees. That the angle θ1 formed by the extending direction of the slit 40 and the longitudinal axis direction of the shaft 10 is 0 degrees means that the extending direction of the slit 40 is the same as the longitudinal axis direction of the shaft 10. By setting the upper limit value of the angle θ1 formed by the extending direction of the slit 40 and the longitudinal axis direction of the shaft 10 within the above range, it is possible to make it difficult for a gap to occur in the slit 40 when the distal side of the shaft 10 of the electrode catheter 1 is in a bent state.

[0071] As shown in FIG. 3, the slit 40 is a region that bisects the length of the shaft 10 in the longitudinal axis direction and has a proximal region 43 located on the proximal side. The conducting wire 30 is preferably disposed in the proximal region 43. That is, the slit 40 has a proximal region 43 that is the proximal region of the region bisecting the length of the shaft 10 in the longitudinal axis direction and a distal region 44 that is the distal region, and it is preferable that the conducting wire 30 is present in the proximal region 43. By disposing the conducting wire 30 in the proximal region 43, when a load in the proximal direction is applied to the conducting wire 30, such as when the distal side of the shaft 10 of the electrode catheter 1 is in a bent state, it becomes difficult for the conducting wire 30 to move significantly within the slit 40. Therefore, it is less likely that the end faces of the slit 40 will separate from each other and a distance will occur.

[0072] As shown in FIG. 3, the slit 40 is a region that trisects the length of the shaft 10 in the longitudinal axis direction, and has a most proximal region 45 located on the most proximal side. It is preferable that the conducting wire 30 is arranged in the most proximal region 45. That is, the slit 40 includes a most proximal region 45 that is the most proximal region among the regions that trisect the length of the shaft 10 in the longitudinal axis direction, a most distal region 47 that is the most distal region, and a central region 46 that is between the most proximal region 45 and the most distal region 47 and is on the distal side of the most proximal region 45 and on the proximal side of the most distal region 47. It is preferable that the conducting wire 30 is present in the most proximal region 45. When a load in the proximal direction is applied to the conducting wire 30, the fact that the conducting wire 30 is arranged in the most proximal region 45 can further enhance the effect of making it difficult for the conducting wire 30 to move greatly within the slit 40.

[0073] As shown in FIG. 2, 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 equivalently stated as that the second end 32 of the conducting wire 30 is not located in the inner cavity of the shaft 10. When the second end 32 of the conducting wire 30 is located outside the shaft 10, the surface area of the conducting wire 30 passing through the slit 40 can be reduced. As a result, it is less likely that a gap will occur between the slit 40 and the conducting wire 30, and the path for a liquid such as blood to penetrate into the inner cavity of the shaft 10 can be reduced. Further, for example, if the connection between the conducting wire 30 and the electrode 20 is made by welding, and the distance between the welding point of the conducting wire 30 and the electrode 20 and the second end 32 of the conducting wire 30 is close, when the second end 32 of the conducting wire 30 is located outside the shaft 10, the distance between the welding point of the conducting wire 30 and the electrode 20 and the slit 40 can be increased, and it can be prevented that the welding point of the conducting wire 30 and the electrode 20 expands the slit 40 to generate a gap. Note that it is preferable that the first end 31 of the conducting wire 30 is the proximal end of the conducting wire 30, and the second end 32 is the distal end of the conducting wire 30.

[0074] 3, the length L3 of the slit 40 in the longitudinal 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. Because the length L3 of the slit 40 is shorter than the length L2 of the electrode 20, when the electrode 20 is placed outside the slit 40, the electrode 20 can cover the entire slit 40. This makes it less likely that a gap will form between the inner surface of the electrode 20 and the slit 40, making it more difficult for liquids such as blood to seep in through this gap.

[0075] The length L3 of the slit 40 in the longitudinal 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 direction of the shaft 10. By setting the upper limit of the ratio of the length L3 of the slit 40 to the length L2 of the electrode 20 within the above range, the slit 40 is less likely to be exposed from the electrode 20 after the electrode 20 is placed outside the slit 40, and liquids such as blood are less likely to enter the slit 40. The lower limit of the ratio of the length L3 of the slit 40 to the length L2 of the electrode 20 is not particularly limited, and can be, for example, 5% or more, 10% or more, or 15% or more.

[0076] The area of the slit 40 in a cross section perpendicular to the depth direction of the slit 40 is preferably smaller than the cross-sectional area perpendicular to the longitudinal axis direction of the conductor 30. The area of the slit 40 is measured with the conductor 30 removed from the slit 40. Since the area of the slit 40 is larger than the cross-sectional area of the conductor 30, gaps are less likely to occur between the conductor 30 and the end face of the slit 40 when the conductor 30 is inserted through the slit 40.

[0077] The area of the slit 40 in a cross-section perpendicular to the depth direction of the slit 40 is preferably 70% or less, more preferably 50% or less, and even more preferably 30% or less of the cross-sectional area perpendicular to the longitudinal axis direction of the conductive wire 30. By setting the upper limit value of the ratio of the area of the slit 40 to the cross-sectional area of the conductive wire 30 within the above range, it becomes difficult for a gap to occur between the conductive wire 30 and the slit 40, and it becomes difficult for a liquid such as blood to enter the lumen of the shaft 10 from this gap. Note that the lower limit value of the ratio of the area of the slit 40 to the cross-sectional area of the conductive wire 30 is not particularly limited, but for example, it can be 1% or more, 3% or more, or 5% or more.

[0078] As shown in FIG. 3, it is preferable that the length L3 of the slit 40 in the longitudinal axis direction of the shaft 10 is longer than the length L4 of the slit 40 in the circumferential direction of the shaft 10. When the length L3 of the slit 40 in the longitudinal axis direction of the shaft 10 is longer than the length L4 of the slit 40 in the circumferential direction, the slit 40 has a shape along the longitudinal axis direction of the shaft 10. As a result, when the distal side of the shaft 10 of the electrode catheter 1 is bent, the slit 40 is less likely to open, and it becomes difficult for a gap to occur between the end face of the slit 40 and the conductive wire 30.

[0079] The length L3 of the slit 40 in the longitudinal axis direction of the shaft 10 is preferably 5 times or more, more preferably 7 times or more, and even more preferably 10 times or more the length L4 of the slit 40 in the circumferential direction of the shaft 10. By setting the lower limit value of the ratio of the length L3 of the slit 40 in the longitudinal axis direction of the shaft 10 to the length L4 of the slit 40 in the circumferential direction within the above range, the shape of the slit 40 is likely to be along the longitudinal axis direction of the shaft 10, and it becomes possible to make the slit 40 less likely to open when the shaft 10 is in a bent state.

[0080] Next, a method for manufacturing the electrode catheter of the present invention will be described. In the following description, parts overlapping with the above description will be omitted.

[0081] The manufacturing method of the electrode catheter 1 includes a preparation step of preparing a shaft 10 extending in the longitudinal direction and having an inner cavity, an electrode 20, and a conductor 30; a slit forming step of forming a slit 40 in the shaft 10 that connects the inner cavity to the outer surface of the shaft 10 and has a width smaller than the diameter of the conductor 30; a conductor insertion step of inserting a first end 31 of the conductor 30 into the slit 40; a conductor connection step of connecting a second end 32 of the conductor 30 to the electrode 20; and an electrode placement step of placing the electrode 20 outside the slit 40.

[0082] In the preparation step, a shaft 10 extending in the longitudinal direction and having a lumen, an electrode 20, and a lead wire 30 are prepared.

[0083] Fig. 4 is a cross-sectional view taken along the longitudinal axis of the shaft 10 during the slit forming step. As shown in Fig. 4, in the slit forming step, a slit 40 is formed in the shaft 10, which connects the inner cavity with the outer surface of the shaft 10 and has a width smaller than the diameter of the conductor 30. The slit 40 is for inserting the conductor 30 from the outside of the shaft 10 into the inner cavity of the shaft 10. The slit 40 can be formed, for example, by using a cutting tool such as a knife or cutter, or a drill or punch, and by inserting the tool at an angle relative to the thickness direction of the tubular wall of the shaft 10 to make an incision in the tubular wall of the shaft 10.

[0084] Because the width of the slit 40 is smaller than the diameter of the conductor 30, when the conductor 30 is inserted into the slit 40, a gap is less likely to form between the end face of the slit 40 and the conductor 30, making it less likely that a path will be formed for liquids such as blood to penetrate into the inner cavity of the shaft 10.

[0085] 5 is a cross-sectional view taken along the longitudinal axis of the shaft 10 during the conductor insertion step. As shown in FIG. 5, in the conductor insertion step, the first end 31 of the conductor 30 is inserted into the slit 40. It is preferable that the first end 31 of the conductor 30 is the proximal end of the conductor 30.

[0086] After the wire insertion process, it is preferable to have a process of exposing the first end 31 of the wire 30 from the proximal end of the shaft 10. By exposing the first end 31 of the wire 30 from the proximal end of the shaft 10, it becomes easier to attach a member for electrically connecting the wire 30 to an external device such as a power supply device of the electrode catheter 1.

[0087] FIG. 6 is a cross-sectional view along the longitudinal axis direction of the shaft 10 in the wire connection process. As shown in FIG. 6, the wire connection process connects the second end 32 of the wire 30 to the electrode 20. Note that the second end 32 of the wire 30 is preferably the distal end of the wire 30.

[0088] The wire connection process may be performed before the wire insertion process or after the wire insertion process. By performing the wire connection process before the wire insertion process, it becomes easier to connect the wire 30 to the electrode 20 by welding or the like. By performing the wire connection process after the wire insertion process, the wire 30 is easy to handle and it becomes easier to insert the wire 30 into the slit 40.

[0089] FIG. 7 is a cross-sectional view along the longitudinal axis direction of the shaft 10 in the electrode arrangement process. As shown in FIG. 7, the electrode arrangement process arranges the electrode 20 outside the slit 40. Note that the electrode arrangement process is preferably performed after the wire connection process.

[0090] Although not shown, it is preferable to have a core material arrangement process of arranging a core material in the inner cavity of the shaft 10 before the slit formation process. By arranging the core material in the inner cavity of the shaft 10 before the slit formation process, the inner cavity of the shaft 10 is filled with the core material, and it becomes easier to cut the inner wall of the shaft 10 with a cutting tool such as a knife or a cutter, or tools such as a drill or a punch, and it becomes easier to form the slit 40 in the tube wall of the shaft 10.

[0091] When the electrode catheter 1 has the 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. 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 easy to securely fix the tip chip connection member 61 to the tip chip 60.

[0092] 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.

[0093] As shown in FIG. 3, the slit 40 is a region that bisects the length of the shaft 10 in the longitudinal axis direction and has a proximal region 43 located on the proximal side. After the slit formation step, it is preferable to have a wire arrangement step of arranging the wire 30 in the proximal region 43. In the wire arrangement step, by arranging the wire 30 in the proximal region 43, when inserting the wire 30 into the lumen of the shaft 10 or when pulling the wire 30 proximally, the wire 30 is less likely to move significantly within the slit 40, the wire 30 is less likely to bend within the lumen of the shaft 10, and the step of inserting the wire 30 into the shaft 10 becomes easier.

[0094] As shown in FIG. 3, the slit 40 is a region that trisects the length of the shaft 10 in the longitudinal axis direction and has the most proximal region 45 located on the most proximal side. After the slit formation step, it is preferable to have a wire arrangement step of arranging the wire 30 in the most proximal region 45. In the wire arrangement step, by arranging the wire 30 in the most proximal region 45, when a load in the proximal direction is applied to the wire 30, the effect of preventing the wire 30 from moving within the slit 40 can be enhanced.

[0095] 7, after the electrode placement step, the second end 32 of the conductor 30 is preferably located outside the shaft 10. By having the second end 32 of the conductor 30 located outside the shaft 10, the surface area of the conductor 30 passing through the slit 40 can be reduced, making it less likely that a gap will occur between the slit 40 and the conductor 30.

[0096] Although not shown, it is preferable to have a wire adhering step after the slit forming step in which the wire 30 is fixed to the slit 40 with an adhesive. By fixing the wire 30 to the slit 40 with an adhesive, the adhesive is present between the slit 40 and the wire 30, making it even less likely that a gap will occur between the slit 40 and the wire 30.

[0097] The adhesive for adhering and fixing the conductive wire 30 to the slit 40 is preferably a polyurethane-based, epoxy-based, cyano-based, fluorine-based, or silicone-based adhesive.

[0098] As described above, the electrode catheter of the present invention comprises a shaft extending in the longitudinal direction, having an inner lumen, and having a slit connecting the inner lumen to the outer surface, an electrode disposed outside the slit, and a conductor connected to the electrode and extending into the inner lumen of the shaft through the slit, the slit having a conductor-present region where the conductor is present and a conductor-absent region where the conductor is not present, the width of the slit in the conductor-absent region being smaller than the width of the slit in the conductor-present region. This configuration of the electrode catheter of the present invention makes it less likely for a gap to form between the conductor and the slit, and makes it more difficult for liquids such as blood to enter the inner lumen of the shaft.

[0099] In addition, 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 a lumen, an electrode, and a conducting wire; a slit forming step of forming a slit in the shaft, in which the lumen communicates with the outer surface of the shaft and the width of the slit is smaller than the diameter of the conducting wire; a conducting wire insertion step of inserting a first end of the conducting wire into the slit; a conducting wire connection step of connecting a second end of the conducting wire to the electrode; and an electrode arrangement step of arranging the electrode outside the slit. 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 is less likely to occur between the conducting wire and the slit, and liquid such as blood is less likely to enter the lumen of the shaft.

Explanation of Signs

[0100] 1: Electrode catheter 10: Shaft 20: Electrode 30: Conducting wire 31: First end 32: Second end 40: Slit 41: Conducting wire existing region 42: Conducting wire non-existing region 43: Proximal region 44: Distal region 45: Most proximal region 46: Central region 47: Most distal region 50: Handle 60: Tip 61: Tip connection member W1: Width of slit in conducting wire existing region W2: Width of slit in conducting wire non-existing region θ1: Angle formed by the extending direction of the slit and the longitudinal axis direction of the shaft L2: Length of electrode L3: Length of slit in the longitudinal axis direction of the shaft L4: Length of slit in the circumferential direction of the shaft

Claims

1. A shaft extending in the longitudinal axis direction, having a lumen, and having a slit through which the lumen and the outer surface communicate; An electrode disposed outside the slit so as to cover the entire slit; A conducting wire connected to the electrode and extending into the lumen of the shaft through the slit; The slit has a wire presence region where the conducting wire is present inside and a wire absence region where the conducting wire is not present inside; An electrode catheter, wherein the width of the slit in the wire absence region is smaller than the width of the slit in the wire presence region.

2. The electrode catheter according to claim 1, wherein an angle formed by the extending direction of the slit as viewed from the upper surface of the slit and the longitudinal axis direction of the shaft is 10 degrees or less (including 0 degrees).

3. The slit is a region that bisects the length of the shaft in the longitudinal axis direction and has a proximal region located on the proximal side; The electrode catheter according to claim 1 or 2, wherein the conducting wire is disposed in the proximal region.

4. The slit is a region that trisects the length of the shaft in the longitudinal axis direction and has a most proximal region located on the most proximal side; The electrode catheter according to any one of claims 1 to 3, wherein the conducting wire is disposed in the most proximal region.

5. The electrode catheter according to any one of claims 1 to 4, wherein the second end of the conducting wire is disposed outside the shaft.

6. The electrode catheter according to any one of claims 1 to 5, wherein the length of the slit in the longitudinal axis direction of the shaft is shorter than the length of the electrode in the longitudinal axis direction of the shaft.

7. The electrode catheter according to any one of claims 1 to 6, wherein the area of the slit in a cross section perpendicular to the depth direction of the slit is smaller than the cross-sectional area of the conducting wire perpendicular to the longitudinal axis direction.

8. The electrode catheter according to any one of claims 1 to 7, wherein the length of the slit in the longitudinal axis direction of the shaft is longer than the length of the slit in the circumferential direction of the shaft.

9. A preparation step of preparing a shaft extending in the longitudinal axis direction and having a lumen, an electrode, and a conducting wire; A slit forming step of forming, in the shaft, a slit through which the lumen and the outer surface of the shaft communicate and whose width is smaller than the diameter of the conducting wire. A wire insertion step of inserting a first end of the wire into the slit; A wire connection step of connecting a second end of the wire to the electrode; An electrode arrangement step of arranging the electrode outside the slit so as to cover the entire slit. A method for manufacturing an electrode catheter having these steps.

10. The method for manufacturing an electrode catheter according to claim 9, further comprising a core material arrangement step of arranging a core material in the inner cavity of the shaft before the slit formation step.

11. The method for manufacturing an electrode catheter according to claim 9 or 10, wherein an angle formed by an extending direction of the slit as viewed from above the slit and a longitudinal axis direction of the shaft is 10 degrees or less (including 0 degrees).

12. The slit is a region that bisects the length of the shaft in the longitudinal axis direction, and has a proximal region located on the proximal side. The method for manufacturing an electrode catheter according to any one of claims 9 to 11, further comprising a wire arrangement step of arranging the wire in the proximal region after the slit formation step.

13. The slit is a region that trisects the length of the shaft in the longitudinal axis direction, and has a most proximal region located on the most proximal side. The method for manufacturing an electrode catheter according to any one of claims 9 to 12, further comprising a wire arrangement step of arranging the wire in the most proximal region after the slit formation step.

14. The method for manufacturing an electrode catheter according to any one of claims 9 to 13, wherein after the electrode arrangement step, the second end of the wire is located outside the shaft.

15. The method for manufacturing an electrode catheter according to any one of claims 9 to 14, further comprising a wire adhesion step of fixing the wire to the slit with an adhesive after the slit formation step.

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