Electrode catheter

Abstract

To provide an electrode catheter capable of reducing a diameter of a shaft and improving efficiency of a manufacturing process.SOLUTION: An electrode catheter 1 comprises: a shaft 2 with a longitudinal axis direction, including a distal-side opening 3 and a lumen 5 communicating with the distal-side opening 3, the shaft 2 including a first side hole 11 for communicating the lumen 5 and the outside of the shaft 2, disposed in a peripheral wall of the shaft 2; a tip electrode 20 disposed in the distal-side opening 3; a first electrode 25 disposed in the first side hole 11; a first conductor wire 31 connected to the first electrode 25 and extending into the lumen 5; a conductive core material 40 connected to the tip electrode 20, extending into the lumen 5, and having tensile strength higher than that of the first conductor wire 31; and a connector 50 disposed on a proximal side of the shaft 2 and including a first terminal to which a proximal end of the core material 40 is connected and a second terminal to which a proximal end of the first lead wire 31 is connected.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an electrode catheter used for measuring electrical potentials of internal organs, primarily the heart, and for cauterizing internal tissue. [Background technology]

[0002] A catheter having an electrode may be used in the examination and treatment of arrhythmia such as atrial fibrillation. During the examination, the electrode catheter is inserted into the cardiac cavity to measure the intracardiac potential and identify the abnormal part of the heart causing the arrhythmia. During the treatment, the electrode catheter is used for ablation surgery, in which a high-frequency current is applied from the catheter electrode to the myocardium causing the arrhythmia, and the source of the arrhythmia is cauterized and electrically isolated from the heart, and for defibrillation treatment, in which an electrical signal is given to the heart from the catheter electrode when atrial fibrillation occurs. In general, an electrode catheter has multiple electrodes arranged on a shaft having a lumen. Conductors are connected to the electrodes, and the conductive wires extend from a conductive wire hole provided in the shaft through the lumen of the shaft to an external device, such as an electrocardiogram or a defibrillator. A connector is provided on the catheter to efficiently connect the multiple conductive wires to the external device.

[0003] For example, Patent Document 1 describes an electromagnetic sensor catheter having a tip electrode, a ring electrode, a lead for the tip electrode, a corresponding lead for the ring electrode, an electromagnetic sensor, a sensor cable, and a pulling wire for deflecting the tip of the catheter.

[0004] Patent Document 2 describes that in an electrode catheter having a tip at the distal end of a shaft, the tip may have a tip connecting member. Patent Document 2 also describes that the tip connecting member may be a pull wire or a lead wire for bending the distal side of the shaft.

[0005] The '399 patent describes a catheter having a shaft assembly, a plurality of electrodes disposed at a distal end of the shaft assembly, and a connector disposed at a proximal end of the shaft assembly for connection to a processing circuit. The '399 patent also describes the catheter having a plurality of cables disposed in each of a first one of the lumens of the shaft assembly, each cable being electrically coupled to the connector and a respective group of electrodes. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 11-507580 [Patent Document 2] JP 2023-68572 A [Patent Document 3] Patent Publication No. 2021-53384 Summary of the Invention [Problem to be solved by the invention]

[0007] As described in Patent Documents 1 and 2, a wire for bending the tip of the catheter or a core material for maintaining the overall shape of the catheter is connected to the tip member. The wire is connected to a handle so that it can be pulled toward the hand. The core material is fixed to the catheter so that it does not move distally or proximally relative to the shaft. In conventional catheters, in order to use the tip member as an electrode, it is necessary to connect a conductor in addition to the wire or core material, which results in a large number of parts, and there is room for improvement in terms of reducing the diameter of the shaft and improving the efficiency of catheter manufacturing.

[0008] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an electrode catheter which enables a shaft to be made thinner and which can be manufactured more efficiently. [Means for solving the problem]

[0009] One embodiment of the electrode catheter of the present invention that can solve the above problems is as follows. [1] A shaft having a longitudinal axis direction, a distal opening, and an inner cavity communicating with the distal opening, the shaft having a peripheral wall provided with a first side hole communicating with the inner cavity and the outside of the shaft; a tip electrode disposed in the distal opening; a first electrode disposed in the first side hole; a first conductor connected to the first electrode and extending into a lumen of the shaft; a conductive core connected to the tip electrode and extending into the lumen of the shaft, the core having a tensile strength greater than that of the first conductor; An electrode catheter having a connector disposed on the proximal side of the shaft and having a first terminal to which the proximal end of the core material is connected and a second terminal to which the proximal end of the first conductor is connected.

[0010] According to the electrode catheter, by connecting a conductive core material to the tip electrode, the core material can function not only to maintain the shape of the catheter but also as a conductor. Since there is no need to connect a conductor separately from the core material to the tip electrode, the number of parts arranged in the shaft can be reduced, making it possible to make the shaft thinner. In addition, since the core material is connected to the connector together with the first conductor, the process of connecting the parts is simplified compared to the conventional method, and the efficiency of catheter manufacturing is improved. Since the position of the core material in the longitudinal direction of the shaft is fixed by connecting the core material to the connector, the rigidity of the electrode catheter is appropriately increased, and good torque transmission can be obtained.

[0011] The electrode catheter of the present invention preferably satisfies the following items [2] to

[13] . [2] The tip electrode has a tensile strength of 800N / mm 2 The electrode catheter described in [1] has the following leads not connected: [3] An electrode catheter as described in [1] or [2], wherein the core material is not fixed to the proximal portion of the shaft. [4] An electrode catheter described in any one of [1] to [3], wherein the tip electrode and the core material are joined with a joining strength that is greater than the tensile strength of the core material and greater than the tensile strength of the first conducting wire. [5] The electrode catheter described in any one of [1] to [4], wherein the tip electrode is fixed only to the shaft and the core material. [6] An electrode catheter described in any one of [1] to [5], wherein R1 / R2≦3.5, where R1 is (DC electrical resistance of the tip electrode)−(DC electrical resistance of the core material)−(DC electrical resistance of the first terminal of the connector) and R2 is (DC electrical resistance of the first electrode)−(DC electrical resistance of the first conducting wire)−(DC electrical resistance of the second terminal of the connector). [7] The electrode catheter described in any one of [1] to [6], wherein the minimum outer diameter of the core material is larger than the minimum outer diameter of the first conducting wire. [8] An electrode catheter described in any one of [1] to [7], wherein the first terminal has a recess that receives the proximal end of the core material, and the maximum inner diameter of the recess of the first terminal is larger than the maximum outer diameter of the proximal end of the core material. [9] The first terminal has a recess for receiving the proximal end of the core material, and the second terminal has a recess for receiving the proximal end of the first conductor, The electrode catheter according to any one of [1] to [8], wherein the recess of the first terminal and the recess of the second terminal have the same shape.

[10] The electrode catheter described in any one of [1] to [9], wherein the tip electrode is an electrode soldered to the core material.

[11] The electrode catheter described in any one of [1] to [9], wherein the tip electrode is an electrode welded to the core material.

[12] The electrode catheter described in any one of [1] to

[11] , wherein the core material is a stranded wire having a first wire and a second wire.

[13] The core material is a stranded wire having a first wire, a second wire, and a third wire, and the first wire has a tensile strength of 800 N / mm 2the second wire is a first conductor of a thermocouple, the third wire is a second conductor of the thermocouple, a proximal end of the first wire is connected to the first terminal, and the connector further has a terminal to which the proximal end of the second wire is connected and a terminal to which the proximal end of the third wire is connected. Effect of the Invention

[0012] According to the electrode catheter, by connecting a conductive core material to the tip electrode, the core material can function not only to maintain the shape of the catheter but also as a conductor. Since there is no need to connect a conductor separately from the core material to the tip electrode, the number of parts arranged in the shaft can be reduced, making it possible to make the shaft thinner. In addition, since the core material is connected to the connector together with the first conductor, the process of connecting the parts is simplified compared to the conventional method, and the efficiency of catheter manufacturing is improved. Since the position of the core material in the longitudinal direction of the shaft is fixed by connecting the core material to the connector, the rigidity of the electrode catheter is appropriately increased, and good torque transmission can be obtained. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a side view of an electrode catheter according to one embodiment of the present invention. [Diagram 2] 2 is a cross-sectional view (partial side view) taken along the longitudinal axis of the electrode catheter shown in FIG. 1. [Diagram 3] 3 is a cross-sectional view of the electrode catheter shown in FIG. 2 in a direction perpendicular to the longitudinal axis direction. [Figure 4] FIG. 3 is an enlarged perspective view of a portion including a connector of the electrode catheter shown in FIG. 2. [Diagram 5] 3 is a schematic diagram showing a connection state between the first conducting wire or the core material shown in FIG. 2 and a connector. FIG. [Figure 6] FIG. 4 is a cross-sectional view showing a modification of the electrode catheter shown in FIG. [Figure 7] FIG. 13 is an enlarged perspective view of a portion including a connector of an electrode catheter according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The present invention will be described in more detail below based on the following embodiments, but the present invention is not limited to the following embodiments, and can be modified as long as it meets the purpose described above and below, and all of these modifications are included in the technical scope of the present invention. In addition, hatching and component symbols may be omitted in each drawing for convenience, but in such cases, the specification and other drawings should be referred to. In addition, the dimensions of various components in the drawings may differ from the actual dimensions because priority is given to helping understand the features of the present invention.

[0015] An electrode catheter according to an embodiment of the present invention will be described with reference to Figs. 1 to 7. Fig. 1 is a side view of an electrode catheter according to an embodiment of the present invention. Fig. 2 is a cross-sectional view (partial side view) along the longitudinal axis of the electrode catheter shown in Fig. 1. Fig. 3 is a cross-sectional view in a direction perpendicular to the longitudinal axis of the electrode catheter shown in Fig. 2. Fig. 4 is an enlarged perspective view of a portion including a connector of the electrode catheter shown in Fig. 2. Fig. 5 is a schematic view showing a connection state between the first conductor or core material and the connector shown in Fig. 2. Fig. 6 is a cross-sectional view showing a modified example of the electrode catheter shown in Fig. 3. Fig. 7 is an enlarged perspective view of a portion including a connector of an electrode catheter according to another embodiment of the present invention. The electrode catheter 1 has a shaft 2, a tip electrode 20, a first electrode 25, a first conductor 31, a core material 40, and a connector 50. Note that Figs. 3 and 6 are schematic views shown to facilitate understanding of the structure of the core material 40, and do not coincide with the cross-sectional view along the longitudinal axis direction x of the electrode catheter 1 shown in Fig. 2.

[0016] The electrode catheter 1 can be used, for example, to examine, treat, defibrillate, etc. cardiac arrhythmias by passing an electric current through the patient's blood vessels from its distal side to the heart and passing an electric current through the tip electrode 20 and / or the first electrode 25.

[0017] In FIG. 1, the electrode catheter 1 has a longitudinal axis direction x, a radial direction y of the shaft 2 perpendicular to the longitudinal axis direction x, and a circumferential direction z along the outer circumference of the shaft 2, and has a distal end and a proximal end in the longitudinal axis direction x. In this specification, the direction toward the user's hand in the longitudinal axis direction x is referred to as the proximal side, and the opposite side to the proximal side, i.e., the direction toward the treatment subject, is referred to as the distal side. The extension direction of the shaft 2 is referred to as the longitudinal axis direction x. The longitudinal axis direction x can also be referred to as the near-far direction. The radial direction y refers to the radial direction of the shaft 2, and in the radial direction y of the shaft 2, the inward direction refers to the direction toward the longitudinal axis center of the shaft 2, and in the radial direction y, the outward direction refers to the direction extending radially from the longitudinal axis center opposite to the inward direction. In addition, in FIG. 1 to FIG. 2, FIG. 4 to FIG. 5, and FIG. 7, the right side of the figure is the proximal side, and the left side of the figure is the distal side. In FIG. 2, the handle 60 is omitted.

[0018] Each member and part that constitutes the electrode catheter 1 has a longitudinal axis direction x, a radial direction y, and a circumferential direction z, which may be the same as or different from the longitudinal axis direction x, radial direction y, and circumferential direction z of the electrode catheter 1.

[0019] The distal portion of the electrode catheter 1 may be bent. In that case, a bend may be imparted to the core material 40. The distal portion of the electrode catheter 1 may be bent before use so that it is curved in its natural state.

[0020] The electrode catheter 1 may be capable of being bent, or may not be capable of being bent. In other words, the shape of the distal portion of the electrode catheter 1 may not be changed from a curved state to an unbent state or vice versa even if the electrode catheter 1 is operated. The bending operation here refers to an operation that is intentionally performed by the user to bend the electrode catheter 1, and does not include cases where the shape of the electrode catheter 1 changes to be curved in accordance with the shape of the body cavity when the electrode catheter 1 is inserted into the patient's body cavity. An example of an electrode catheter 1 that cannot be bent is one in which a pull wire for bending is not connected to the tip electrode 20.

[0021] The shaft 2 has a longitudinal axis direction x, and has a distal opening 3 and an inner cavity 5 communicating with the distal opening 3, as shown in Fig. 2. The distal opening 3 is preferably an opening whose normal vector of the opening surface faces the distal side. A tip electrode 20 is disposed in the distal opening 3. In Fig. 2, the position of the distal opening 3 is indicated by a dashed line.

[0022] The shaft 2 may have a proximal opening 4. The proximal opening 4 is preferably in communication with the inner cavity 5. The first conductive wire 31 and the core material 40 preferably extend from the proximal opening 4 toward the proximal side.

[0023] The shaft 2 may have a single lumen structure having one lumen, or a multi-lumen structure having multiple lumen. If the shaft 2 has one lumen, there is no partition or the like that divides the lumen inside the shaft 2, so that the flexibility of the shaft 2 can be increased and the insertion of the electrode catheter 1 can be improved. If the shaft 2 has multiple lumen, the conductor wires and the core material 40 placed in the lumen can be placed in separate lumen to prevent them from contacting each other and prevent damage to the conductor wires and the core material 40. It is preferable that the lumen of the shaft 2 extends in the longitudinal axis direction x of the shaft 2, and it is preferable that each of the multiple lumen of the shaft 2 extends in the longitudinal axis direction x of the shaft 2.

[0024] Examples of the material for the shaft 2 include synthetic resins such as polyolefin resins, such as polyethylene and polypropylene, polyamide resins, such as nylon, polyester resins, such as PET, polyimide resins, aromatic polyether ketones, such as PEEK, polyether polyamide resins, polyurethane resins, fluorine resins, such as PTFE, PFA, ETFE, vinyl chloride resins, and silicone resins, as well as natural rubber. These may be used alone or in combination of two or more.

[0025] The shaft 2 may have a single layer structure or a multi-layer structure. When the shaft 2 has a multi-layer structure, for example, the shaft 2 may have a structure in which a metal braid such as stainless steel, carbon steel, or nickel-titanium alloy is used as an intermediate layer of a resin tube constituting the shaft 2. The material constituting the shaft 2 is preferably a polyamide resin, and more preferably a polyamide elastomer. When the material constituting the shaft 2 is a polyamide elastomer, the outer surface of the shaft 2 has good slipperiness, and the shaft 2 has appropriate rigidity, so that the electrode catheter 1 can be easily inserted into a blood vessel.

[0026] The length of the shaft 2 in the longitudinal direction x can be selected to be an appropriate length for treatment. For example, the length of the shaft 2 in the longitudinal direction x can be 400 mm or more and 2000 mm or less. The length of the shaft 2 in the longitudinal direction x is preferably relatively long when the tip of the electrode catheter 1 is inserted from a lower limb vein and delivered to the heart, and may be relatively short when the tip of the electrode catheter 1 is inserted from a subclavian vein or a jugular vein and delivered to the heart.

[0027] The outer diameter of the shaft 2 is preferably 0.5 mm or more, more preferably 0.7 mm or more, and even more preferably 1.0 mm or more. By setting the lower limit of the outer diameter of the shaft 2 within the above range, the shaft 2 can be given an appropriate rigidity and the insertability into a blood vessel can be improved. The outer diameter of the shaft 2 is preferably 3.0 mm or less, more preferably 2.8 mm or less, and even more preferably 2.5 mm or less. By setting the upper limit of the outer diameter of the shaft 2 within the above range, the outer diameter of the electrode catheter 1 can be prevented from becoming too large, and low invasiveness can be improved. The outer diameter of the shaft 2 may be 1.8 mm or less, 1.7 mm or less, 1.5 mm or less, 1.0 mm or less, or 0.8 mm or less. This allows the electrode catheter 1 to be used as a microcatheter with a small outer diameter at the distal end, and the distal end of the electrode catheter 1 can be delivered to the periphery of the coronary sinus.

[0028] The thickness of the shaft 2, i.e., the thickness of the peripheral wall, is preferably 50 μm or more, more preferably 100 μm or more, and even more preferably 150 μm or more. By setting the lower limit of the thickness of the shaft 2 within the above range, it is possible to increase the rigidity of the shaft 2 and provide an electrode catheter 1 with good insertability into a blood vessel. Moreover, the thickness of the shaft 2 is preferably 350 μm or less, more preferably 300 μm or less, and even more preferably 250 μm or less. By setting the upper limit of the thickness of the shaft 2 within the above range, the lumen 5 of the shaft 2 can be widened, and the electrodes of the electrode catheter 1 can be multipolarized.

[0029] 1, a handle 60 may be connected to the proximal side of the shaft 2. A user can easily operate the electrode catheter 1 by grasping the handle 60.

[0030] A first side hole 11 that connects the inner cavity 5 to the outside of the shaft 2 is arranged in the peripheral wall (side wall) of the shaft 2. The side hole is provided so as to penetrate the peripheral wall of the shaft 2. Preferably, the shaft 2 has a plurality of side holes that are spaced apart in the longitudinal axis direction x. In FIG. 2, the shaft 2 has a first side hole 11, a second side hole 12, and a third side hole 13.

[0031] The method for forming the side hole in the shaft 2 is not particularly limited, but examples include a method of piercing the peripheral wall of the shaft 2 with a rod-shaped member having a sharp tip, such as a needle or an awl, or a method of irradiating the peripheral wall with laser light.

[0032] The shape of the side hole when the shaft 2 is viewed from the outside in the radial direction y is not particularly limited, and may be, for example, a circle, an oval, a polygon, or a combination of these, or may be an irregular shape. The oval shape includes an ellipse, an egg, and a rounded rectangle. The same applies in the following description.

[0033] The electrode catheter 1 has a first electrode 25 disposed in the first side hole 11. Preferably, the shaft 2 has a plurality of side holes disposed at intervals in the longitudinal axis direction x, and an electrode is disposed on the outside of each side hole. In FIG. 2, the first electrode 25 is disposed in the first side hole 11, the second electrode 26 is disposed in the second side hole 12, and the third electrode 27 is disposed in the third side hole 13. Hereinafter, the electrode disposed in the side hole of the shaft 2 may be referred to as a side electrode 24. It is preferable that one side electrode 24 is disposed for one side hole, but one side electrode 24 may be disposed for multiple side holes. The side electrode 24 is preferably disposed on the outer surface of the shaft 2. It is preferable that the first electrode 25 is the electrode disposed most distally except for the tip electrode 20.

[0034] The side electrode 24 can function as a measurement electrode or a reference electrode when measuring a potential, and can function as an electrode for passing a high-frequency current or an electrode for applying an electrical signal.

[0035] As can be seen from Figs. 1 and 2, the side electrode 24 may be a ring-shaped electrode, or may have a cross section with a notch in a C-shape, or a coil shape with a wound wire, etc. When the side electrode 24 has such a shape, the side electrode 24 can be disposed on the outer surface of the shaft 2 by crimping the side electrode 24 to the shaft 2. When the side electrode 24 has a shape having a diameter such as a ring shape, a C-shape, or a coil shape, it is preferable that the inner diameter of the side electrode 24 is smaller than the maximum outer diameter of the shaft 2. This makes it difficult for the end of the side electrode 24 to get caught on other objects, improving the insertability and making it difficult to damage the body cavity wall such as the inner wall of the heart or blood vessels.

[0036] The side electrode 24 may be a plate electrode formed independently in an island shape when viewed from the outside of the shaft 2. The shape of the plate electrode may be any shape, such as a polygonal shape such as a rectangle or a square, or a circle. It is preferable that at least one of the inner and outer surfaces of such a plate electrode is curved so as to easily fit along the curved surface of the shaft 2.

[0037] A recess for disposing the side electrode 24 may be formed on the radially outer side of the side hole of the shaft 2. Since the side electrode 24 can be disposed in the recess, it is possible to prevent the side electrode 24 from protruding outward in the radial direction y, and to prevent the side electrode 24 from getting caught on a body cavity wall such as the inner wall of a blood vessel or the heart, thereby reducing the insertability or damaging the body cavity wall. Examples of methods for forming a recess in the peripheral wall of the shaft 2 include cutting with a drill or the like, applying pressure with a rod-shaped object, thermal processing in which a heated rod-shaped object is pressed against the body cavity wall, and irradiation with laser light.

[0038] The side electrode 24 only needs to be conductive, and can be made of a metal or a mixture containing a metal and a resin. In particular, metals such as platinum, platinum-iridium alloy, stainless steel, and tungsten, or conductive resins are preferably used as the material for the side electrode 24. When the side electrode 24 is made of conductive resin, it is preferable to mix a contrast agent such as barium sulfate or bismuth oxide into the side electrode 24 so that the electrode can be viewed under X-ray fluoroscopy.

[0039] The number of side electrodes 24 arranged on the electrode catheter 1 is not limited, and may be, for example, 2 or more, 3 or more, 5 or more, 8 or more, 10 or more, 15 or more, 50 or less, 40 or less, 30 or less, 25 or less, 20 or less, etc. Depending on the purpose of using the electrode catheter 1, the electrode catheter 1 may have a plurality of side electrode groups including a plurality of side electrodes 24. In this case, the plurality of side electrode groups may be arranged spaced apart in the longitudinal axis direction x.

[0040] When the electrode catheter 1 has a plurality of side electrodes 24, the size of each side electrode 24 may be the same or different. The different sizes of the electrodes refer, for example, to the length of each side electrode 24 in the longitudinal axis direction x being different.

[0041] The electrode catheter 1 has a tip electrode 20 disposed at the distal opening 3. The tip electrode 20 is preferably disposed so as to block the distal opening 3. Examples of the tip electrode 20 include a hollow tube member, a hemispherical member, a lid-shaped member, and the like. The tip electrode 20, like the side electrode 24, can function as a measurement electrode or a reference electrode during potential measurement, an electrode for passing a high-frequency current, and an electrode for applying an electrical signal. When the tip electrode 20 blocks the distal opening 3, it can also prevent unexpected foreign matter such as blood from entering the lumen 5 of the shaft 2 when the electrode catheter 1 is in use.

[0042] The material constituting the tip electrode 20 can refer to, for example, the material constituting the above-mentioned side electrode 24. The materials constituting the tip electrode 20 and the first electrode 25 may be the same or different.

[0043] In the longitudinal axis direction x, the tip electrode 20 is preferably disposed distally of the first electrode 25. In Fig. 1 and Fig. 2, the tip electrode 20, the first electrode 25, the second electrode 26, and the third electrode 27 are disposed in this order from the distal side in the longitudinal axis direction x.

[0044] The first conducting wire 31 is connected to the first electrode 25 and extends into the lumen 5 of the shaft 2. Specifically, the first conducting wire 31 has a longitudinal direction and has a distal end and a proximal end in the longitudinal direction. The distal end of the first conducting wire 31 is preferably connected to the inner surface of the first electrode 25. The proximal end of the first conducting wire 31 is connected to a second terminal 52 of the connector 50, which will be described later.

[0045] The electrode catheter 1 preferably has a plurality of conductors including a first conductor 31. In FIG. 2, the electrode catheter 1 has three conductors, a first conductor 31, a second conductor 32, and a third conductor 33. The first conductor 31 is connected to the first electrode 25, the second conductor 32 is connected to the second electrode 26, and the third conductor 33 is connected to the third electrode 27. Each of the plurality of conductors is preferably connected to one side electrode 24 and extends into the lumen 5 of the shaft 2. Each of the plurality of conductors is preferably connected to the inner surface of the side electrode 24. Also, the proximal ends of the plurality of conductors are preferably connected to terminals of the connector 50.

[0046] The conductor wire may be any wire that is conductive, and may be, for example, a copper wire, an iron wire, a stainless steel wire, a piano wire, a tungsten wire, a nickel-titanium alloy wire, etc. Among these, a stainless steel wire is particularly preferred because it has linearity and rigidity, making it easy to pass the conductor wire through the side hole of the shaft 2, and because disconnection of the connection between the conductor wire and the side electrode 24 is unlikely to occur.

[0047] The conductor may be a single wire or a stranded wire. The cross-sectional shape of the conductor perpendicular to the longitudinal axis direction may be, for example, a circle, an oval, a polygon, or a combination of these. The major diameter of the conductor is not particularly limited, and is preferably 0.05 mm or more, more preferably 0.08 mm or more, even more preferably 0.1 mm or more, and preferably 0.3 mm or less, more preferably 0.2 mm or less, and even more preferably 0.15 mm or less. The major diameter of the conductor means the diameter of the circumscribed circle of the conductor in a cross-section perpendicular to the longitudinal axis direction, regardless of whether the conductor is a single wire or a stranded wire, and regardless of the cross-sectional shape. The same applies to the description of the major diameter of the core material 40 described later.

[0048] It is preferable that the conductor is covered with a coating material. It is more preferable that the coating material is provided on the conductor other than the end connected to the side electrode 24. This makes it possible to prevent a short circuit with adjacent members. The coating material is provided on the outer circumference of the conductor.

[0049] The coating material for the conductor wire may be made of any insulating material, and examples of such materials 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.

[0050] The conductive wire and the side electrode 24 can be connected by a method such as soldering, laser welding, resistance welding, adhesion with an adhesive, etc. The conductive wire and the side electrode 24 may be directly connected, or the conductive wire and the side electrode 24 may be indirectly connected via a conductive member.

[0051] The electrode catheter 1 has a conductive core material 40. The core material 40 is connected to the tip electrode 20 and extends into the lumen 5 of the shaft 2. By connecting the conductive core material 40 to the tip electrode 20, the core material 40 can function not only to maintain the shape of the electrode catheter 1 but also as a conductor. Since the core material 40 in the electrode catheter 1 has the function of a conductor, there is no need to connect a conductor to the tip electrode 20 separately from the core material 40, and the electrode catheter 1 can have a smaller number of conductors than the number of electrodes. As a result, the number of parts arranged in the shaft 2 can be reduced, making it possible to reduce the diameter of the shaft 2. Alternatively, a larger space can be secured in the shaft 2 compared to the conventional electrode catheter 1.

[0052] The core material 40 has a longitudinal axis direction and is an elongated member having a distal end and a proximal end in the longitudinal axis direction. The core material 40 preferably extends along the longitudinal axis direction x of the shaft 2 from the distal end to the proximal end of the shaft 2. The core material 40 may be a hollow member having an inner cavity, such as a coil or a tube. In order to easily maintain the overall shape of the electrode catheter 1, the core material 40 is preferably a solid member, and more preferably a linear or rod-shaped member, for example.

[0053] The tensile strength of the core material 40 is greater than that of the first conducting wire 31. Therefore, the core material 40 makes it easier to maintain the overall shape of the shaft 2. In order to increase the tensile strength of the core material 40 compared to the first conducting wire 31, it is preferable that the minimum outer diameter of the core material 40 is greater than the minimum outer diameter of the first conducting wire 31. It is more preferable that the minimum outer diameter of the core material 40 is greater than the minimum outer diameter of all the conducting wires. In other words, it is preferable that the minimum major axis of the core material 40 is greater than the minimum major axis of the first conducting wire 31, and more preferably greater than the minimum major axis of all the conducting wires. By setting the diameter of the core material 40 in this manner, the overall shape of the shaft 2 can be appropriately maintained when the electrode catheter 1 is inserted into the body cavity.

[0054] The tensile strength of the core material 40 is 1000N / mm 2 It is preferable that the resistance is 1100N / mm or more. 2 More preferably, it is 1200N / mm 2 It is more preferable that the lower limit is set to 2000 N / mm or more. By setting the lower limit in this way, the core material 40 is less likely to break. The tensile strength of the core material 40 is 2000 N / mm 2 It is preferable that the resistance is less than 1900N / mm 2 More preferably, it is 1800N / mm 2 It is even more preferable that the upper limit is not more than 1. By setting the upper limit in this manner, it is possible to obtain an electrode catheter 1 that has good conformability to the shape of a body cavity.

[0055] Examples of materials constituting the core material 40 include metal materials such as iron, copper, silver, stainless steel, tungsten, nickel, titanium, and alloys thereof, among which stainless steel is preferable. Stainless steel has straightness and rigidity, which makes it easier to maintain the overall shape of the shaft 2.

[0056] The core material 40 may be a solid wire as shown in Fig. 3, or a stranded wire as shown in Fig. 6. In other words, the core material 40 may be composed of one or more wires. The cross-sectional shape perpendicular to the longitudinal axis direction of the wire constituting the core material 40 may be, for example, a circle, an ellipse, a polygon, or a combination of these.

[0057] The proximal portion of the core material 40 may be fixed to the shaft 2. The proximal portion of the core material 40 may be fixed to the proximal portion of the shaft 2, for example, to the inner wall of the shaft 2. The proximal portion of the core material 40 may be fixed to the shaft 2 directly or indirectly via another member. By fixing the proximal portion of the core material 40 to the shaft 2 in this manner, the rigidity of the electrode catheter 1 is appropriately increased and torque transmission is improved, so that the rotation operation of the handle 60 is easily transmitted to the distal end side of the electrode catheter 1.

[0058] The distal portion of the core material 40 may be fixed to the shaft 2. The distal portion of the core material 40 may be fixed to the shaft 2 directly or indirectly via another member. Fixing the distal portion of the core material 40 in this manner makes it easier to hold the core material 40 at an appropriate position within the shaft 2.

[0059] It is preferable that the distal portion of the core material 40 is fixed to the shaft 2 proximal to the tip electrode 20 and distal to the first electrode 25, and it is more preferable that the distal portion of the core material 40 is fixed to the inner wall of the shaft 2 proximal to the tip electrode 20 and distal to the first electrode 25. By fixing the distal portion of the core material 40 to the shaft 2 at such a position, it is possible to prevent the core material 40 from falling off the shaft 2 while maintaining the flexibility of the shaft 2. For example, by filling the inner cavity 5 of the shaft 2 proximal to the tip electrode 20 and distal to the first electrode 25 with an adhesive, it is possible to fix the core material 40 to the shaft 2 via the adhesive.

[0060] The proximal or distal portion of the core material 40 can be fixed to the shaft 2 by, for example, soldering, welding such as laser welding or resistance welding, or bonding with an adhesive.

[0061] It is preferable that the core material 40 is not fixed to the proximal portion of the shaft 2, and it is more preferable that the proximal portion of the core material 40 is not fixed to the proximal portion of the shaft 2. Since the proximal portion of the core material 40 is not fixed to the shaft 2, it is easier to rotate the handle 60, and it is preferable because stress concentration does not occur at the joint between the core material 40 and the shaft 2.

[0062] In the longitudinal axis direction x, it is preferable that the core material 40 is not fixed to the shaft 2 proximal to the proximal end of the most proximal side electrode 24, and it is more preferable that the core material 40 is not fixed to the shaft 2 proximal to the proximal end of the most distal side electrode 24. Since the core material 40 is not fixed to the shaft 2 over a wide range in the longitudinal axis direction x in this manner, the core material 40 can easily move freely within the shaft 2 during the procedure, making it easier to rotate the handle 60.

[0063] The tip electrode 20 may be directly connected to the core material 40, or the tip electrode 20 may be indirectly connected to the core material 40 via a conductive member. In particular, it is preferable that the tip electrode 20 is joined to the core material 40. It is preferable that the tip electrode 20 is an electrode soldered to the core material 40. The tip electrode 20 may also be an electrode welded to the core material 40, for example, an electrode that is laser welded or resistance welded. By such a method, the tip electrode 20 and the core material 40 can be electrically connected. Furthermore, the use of welding can increase the joint strength compared to solder jointing. In addition, the core material 40 and the tip electrode 20 can be connected by other methods such as adhesion with a conductive adhesive.

[0064] The bonding strength between the tip electrode 20 and the core material 40 is not particularly limited, but is, for example, 1800 N / mm 2 Below, 1700N / mm 2 Below, 1600N / mm 2 It may be less than 1000N / mm 2 More than 1100N / mm 2 More than 1200N / mm 2By setting the joining strength in this manner, it is possible to prevent the tip electrode 20 from falling off the core material 40 when the electrode catheter 1 is inserted into a body cavity.

[0065] The tip electrode 20 and the core material 40 are preferably joined with a joint strength that is greater than the tensile strength of the core material 40 and greater than the tensile strength of the first conductive wire 31. Joining the tip electrode 20 and the core material 40 with such a joint strength can prevent the tip electrode 20 from falling off the core material 40 when the electrode catheter 1 is inserted into a body cavity.

[0066] It is preferable that the tip electrode 20 is fixed only to the shaft 2 and the core material 40. By limiting the number of parts connected to the tip electrode 20, a large space can be secured within the shaft 2. For example, the tip electrode 20 has a tensile strength of 800 N / mm 2 The following conductors are preferably not connected. By not connecting such conductors to the tip electrode 20, the number of parts arranged inside the shaft 2 can be reduced. The tip electrode 20 is preferably bonded to the inner wall of the shaft 2 and to the distal end face of the shaft 2. The proximal end of the tip electrode 20 is preferably bonded to the distal end of the core material 40. The distal end of the tip electrode 20 is preferably located distal to the distal end of the shaft 2.

[0067] The tensile strength of the first conducting wire 31 is 800N / mm 2 It is preferable that the tensile strength of all the conductors connected to the side electrode 24 is 800 N / mm 2 It is more preferable that the tensile strength of all the conductors in the electrode catheter 1 is 800 N / mm 2 The tensile strength of all the conductors connected to the side electrode 24 may be 750 N / mm 2 It is more preferable that the tensile strength of all the conductors connected to the side electrode 24 is 700 N / mm 2 It is particularly preferable that the tensile strength of all the conductors of the electrode catheter 1 is 750 N / mm 2 or less than 700N / mm 2Setting the upper limit in this manner makes it easier to wire the conductor inside the shaft 2. The tensile strength of the first conductor 31 is 300 N / mm 2 It is preferable that the tensile strength of all the conductors connected to the side electrode 24 is 300 N / mm 2 More preferably, it is 400N / mm 2 More preferably, it is 500 N / mm 2 It is particularly preferable that the tensile strength of all the conductors in the electrode catheter 1 is 300 N / mm 2 More than 400N / mm 2 or more than 500N / mm 2 By setting the lower limit in this way, the conductor wire is less likely to break.

[0068] The tensile strength of the core material 40 and the conductor wire can be measured by the method described in JIS C 3002 (Test methods for electrical copper wires and aluminum wires).

[0069] It is preferable that the core material 40 does not have a covering material that covers the outer periphery. It is preferable that the core material 40 is arranged so as to face the first conducting wire 31 in the radial direction y of the shaft 2. That is, it is preferable that the core material 40 faces the first conducting wire 31 in an unfixed state in the radial direction y of the shaft 2. By not providing a covering material on the core material 40 in this way, it is possible to ensure a large space within the shaft 2. Note that it is preferable that a covering material is provided on a portion of the conducting wire other than the end connected to the side electrode 24, and that no covering material is provided on the core material 40.

[0070] The covering material is composed of an insulating material, and examples of the covering material 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.

[0071] The electrode catheter 1 may have a radiopaque marker. Thus, the radiopaque marker in the body cavity under X-ray fluoroscopy may be disposed, for example, at the distal portion of the core material 40. The radiopaque marker may contain a radiopaque material. Examples of the radiopaque material include lead, barium, iodine, tungsten, gold, platinum, iridium, platinum-iridium alloy, stainless steel, titanium, cobalt-chromium alloy, palladium, and tantalum.

[0072] As shown in FIG. 2, the connector 50 is disposed on the proximal side of the shaft 2. As shown in FIG. 4, the connector 50 has at least a first terminal 51 and a second terminal 52. The proximal end of the core material 40 is connected to the first terminal 51. The proximal end of the first conductor 31 is connected to the second terminal 52. Since the core material 40 is connected to the connector 50 together with the first conductor 31, the connecting process of the members is simplified compared to the conventional art, and the catheter manufacturing efficiency is improved. In addition, by using the connector 50, the first conductor 31 and the core material 40 can be efficiently connected to an external device 70 such as an electrocardiograph or a defibrillator as shown in FIG. 1. Furthermore, since the core material 40 is connected to the connector 50, the position of the core material 40 with respect to the longitudinal axis direction x of the shaft 2 is fixed, and the rigidity of the electrode catheter 1 is appropriately increased, so that good torque transmission can be obtained.

[0073] As shown in Fig. 5, the connector 50 may have a first connection portion 61 and a second connection portion 62. The first connection portion 61 is a portion provided with terminals to which the conductor wires extending from each electrode of the electrode catheter 1 and the core material 40 are connected, and is preferably disposed in a distal portion of the connector 50. The second connection portion 62 is a portion connected to an external device 70 such as an electrocardiogram or a defibrillator, and is preferably disposed in a proximal portion of the connector 50. Although Figs. 1 and 5 show an example in which the second connection portion 62 is directly connected to the connection portion 71 of the external device 70, the connector 50 and the external device 70 may be connected via a relay member such as a cable or an adapter (not shown).

[0074] In order to electrically connect the tip electrode 20 and the side electrode 24 to the external device 70 via the connector 50, each terminal is preferably made of a conductive material. For the material of the terminal, reference can be made to those listed as the materials of the tip electrode 20 or the side electrode 24. Parts of the connector 50 other than the terminals, for example the housing, can be made of an insulating material. For the material of the parts other than the terminals, reference can be made to those listed as the materials of the shaft 2.

[0075] As shown in Figures 1 and 2, the connector 50 may be disposed proximal to the proximal end of the shaft 2. The connector 50 may be fixed directly to the proximal portion of the shaft 2 or indirectly via another member. The connector 50 may be detachably fixed to the proximal portion of the shaft 2. It is preferable that the connector 50 is not joined to the distal portion of the shaft 2.

[0076] The connector 50 preferably has a plurality of terminals including a first terminal 51 and a second terminal 52. The number of terminals of the connector 50 can be set appropriately depending on the number of conductors connected to the side electrode 24 or the number of wires constituting the core material 40, and may be, for example, 2 or more, 3 or more, 4 or more, 6 or more, 10 or more, or 12 or more. From the viewpoint of miniaturization of the connector 50, the number of terminals is preferably 26 or less, 20 or less, or 14 or less. The number of terminals of the connector 50 is preferably the same as the total number of conductors connected to the side electrode 24 and the number of wires constituting the core material 40.

[0077] Figure 4 shows an example in which connector 50 has, in addition to first terminal 51 and second terminal 52, a third terminal 53 to which the proximal end of second conducting wire 32 is connected, and a fourth terminal 54 to which the proximal end of third conducting wire 33 is connected.

[0078] The shape of the housing of the connector 50 is not particularly limited, and may be, for example, a polyhedron. When the connector 50 is a polyhedron as shown in Fig. 4, it is preferable that all terminals to which the conductors or wires constituting the core material 40 are connected are arranged on one flat or curved surface constituting the polyhedron.

[0079] It is preferable that each terminal of the connector 50 is connected to one of the conductors or wires constituting the core material 40. In Fig. 3, the core material 40 is a solid wire, and in Fig. 4, the proximal end of the core material 40 is connected to a first terminal 51. In Fig. 6, the core material 40 is a stranded wire consisting of a first wire material 41, a second wire material 42, and a third wire material 43, and in Fig. 7, the proximal end of the first wire material 41 is connected to a first terminal 51, the proximal end of the second wire material 42 is connected to a fifth terminal 55, and the proximal end of the third wire material 43 is connected to a sixth terminal 56.

[0080] The shape of each terminal of connector 50 is not particularly limited, and may be a convex shape (pin insert) or a concave shape (socket insert).

[0081] When R1 is (DC resistance of the tip electrode 20)-(DC resistance of the core material 40)-(DC resistance of the first terminal 51 of the connector 50) and R2 is (DC resistance of the first electrode 25)-(DC resistance of the first conductor 31)-(DC resistance of the second terminal 52 of the connector 50), it is preferable that R1 / R2≦3.5. It is more preferable that R1 / R2≦3.4, and it is even more preferable that R1 / R2≦3.2. It is also preferable that R1 / R2≧2.0, it is more preferable that R1 / R2≧2.2, and it is even more preferable that R1 / R2≧2.4. By setting the DC resistance of the core material 40 and the first electrode 25 in this way, it becomes easier to measure the intracardiac potential using the potential difference between the core material 40 and the first electrode 25.

[0082] 5, first terminal 51 preferably has a recess 511 that receives the proximal end of core material 40. In this case, the maximum inner diameter of recess 511 of first terminal 51 is preferably larger than the maximum outer diameter of the proximal end of core material 40. By adjusting the diameter of recess 511 in this manner, core material 40 can be placed in recess 511, and different types of components such as core material 40 and conductors can be connected to connector 50 without any problems.

[0083] 5, it is preferable that the first terminal 51 has a recess 511 for receiving the proximal end of the core material 40, and the second terminal 52 has a recess 521 for receiving the proximal end of the first conductor 31. Since the terminals have a shape that easily receives the linear or rod-shaped core material 40 or conductor, it becomes easy to connect the connector 50 and the core material 40 or conductor when manufacturing the electrode catheter 1.

[0084] The terminals and the core material 40 or the conductive wire connected to the side electrode 24 can be connected by methods such as soldering, laser welding, resistance welding, adhesion with an adhesive, etc. In Fig. 5, an example is shown in which the first terminal 51 and the core material 40, and the second terminal 52 and the first conductive wire 31 are connected by solder 58.

[0085] In the connector 50, an insulating member 59 is preferably arranged so as to cover at least one of the connection portion between the first terminal 51 and the core material 40 and the connection portion between the second terminal 52 and the first conducting wire 31. By providing the insulating member 59, a short circuit between the core material 40 and the first conducting wire 31 can be prevented, and the strength of the connection portion between the first terminal 51 and the core material 40 and / or the connection portion between the second terminal 52 and the first conducting wire 31 can be improved. For example, an adhesive can be used as the insulating member 59. In FIG. 5, one insulating member 59 covers the entire connection portion between the first terminal 51 and the core material 40 and the connection portion between the second terminal 52 and the first conducting wire 31. In another embodiment, one insulating member may cover the connection portion between the first terminal 51 and the core material 40, and another insulating member may cover the connection portion between the second terminal 52 and the first conducting wire 31. It is preferable that all of the multiple connection portions between the core material or the conducting wire and the terminal are covered with an insulating member.

[0086] The shapes of the multiple terminals of the connector 50 may be different, but are preferably the same. In particular, it is preferable that all of the terminals that receive the conductors connected to the core material 40 or the side electrode 24 have recesses. This makes it easier to connect the connector 50 to the core material 40 or the conductors when manufacturing the electrode catheter 1.

[0087] As can be seen from Fig. 5, it is preferable that recess 511 of first terminal 51 and recess 521 of second terminal 52 have the same shape. It is also more preferable that all terminals of connector 50 each have a recess, and that the recesses of all terminals have the same shape. Because the terminal to which core material 40 is connected and the terminal to which the conductor wire is connected have the same shape, it is possible to use a general-purpose product as connector 50, and therefore electrode catheter 1 can be manufactured with an inexpensive configuration.

[0088] Next, an example of a stranded wire having multiple wires in the core material 40 will be described. The core material 40 may be, for example, a stranded wire having a first wire 41 and a second wire 42. In other words, it may be a stranded wire made of multiple single wires. By using multiple wires in this way, different functions can be given to each wire, so the core material 40 can be configured to be multifunctional.

[0089] As shown in Figures 6 to 7, the core material 40 may have a first wire 41, a second wire 42, and a third wire 43. In this case, the first wire 41 has a tensile strength of 800 N / mm 2 The second wire 42 may be a first conductor of a thermocouple, and the third wire 43 may be a second conductor of a thermocouple. The proximal end of the first wire 41 is connected to the first terminal 51, and the connector 50 may further have a terminal to which the proximal end of the second wire 42 is connected and a terminal to which the proximal end of the third wire 43 is connected. By forming the core 40 from a twisted wire consisting of a conductor and a thermocouple in this way, the tip electrode 20 can be used not only for measuring intracardiac potentials and defibrillation, but also for measuring temperatures inside the body.

[0090] In FIG. 7, the electrode catheter 1 has a core material 40, a first conducting wire 31, a second conducting wire 32, and a third conducting wire 33. The first conducting wire 31 to the third conducting wire 33 are connected to the first electrode 25, the second electrode 26, and the third electrode 27, respectively, as in the embodiment of FIG. 3. The core material 40 has a first wire 41, a second wire 42, and a third wire 43, and the proximal end of the first wire 41 is connected to a first terminal 51, the proximal end of the second wire 42 is connected to a fifth terminal 55, and the proximal end of the third wire 43 is connected to a sixth terminal 56. The first conducting wire 31 to the third conducting wire 33 are connected to the second terminal 52, the third terminal 53, and the fourth terminal 54, respectively, as in the embodiment of FIG. 3.

[0091] When the core material 40 is a stranded wire made up of a plurality of wires, each wire may have a larger or smaller diameter than the conductor connected to the side electrode 24 . [Explanation of symbols]

[0092] 1: Electrode catheter 2: Shaft 3: Distal opening 5: lumen 11: 1st side hole 12:Second side hole 13: Third side hole 20:Tip electrode 25: 1st electrode 26:Second electrode 27:Third electrode 31: 1st conductor 32:Second conductor 33: Third conductor 40: Core material 50: Connector 51: 1st terminal 52: 2nd terminal 53: 3rd terminal 54: 4th terminal 55: 5th terminal 56: 6th terminal 60: Handle 70: External equipment

Claims

1. A shaft having a longitudinal axis direction, a distal opening, and an inner cavity communicating with the distal opening, the shaft having a first side hole disposed in a peripheral wall thereof, the first side hole communicating with the inner cavity and the outside of the shaft; a tip electrode disposed in the distal opening; A first electrode disposed in the first side hole; a first lead connected to the first electrode and extending into a lumen of the shaft; a conductive core connected to the tip electrode and extending into the lumen of the shaft, the core having a tensile strength greater than that of the first wire; An electrode catheter having a connector disposed on the proximal side of the shaft and having a first terminal to which the proximal end of the core material is connected and a second terminal to which the proximal end of the first conductor is connected.

2. The tip electrode has a tensile strength of 800 N / mm ２ 2. The electrode catheter of claim 1, wherein the following leads are not connected:

3. 3. The electrode catheter of claim 1, wherein the core is not fixed to the proximal portion of the shaft.

4. 3. The electrode catheter according to claim 1, wherein the tip electrode and the core material are joined with a joining strength that is greater than a tensile strength of the core material and greater than a tensile strength of the first conducting wire.

5. 3. The electrode catheter according to claim 1, wherein the tip electrode is fixed only to the shaft and the core material.

6. R １ (DC electrical resistance value of the tip electrode) - (DC electrical resistance value of the core material) - (DC electrical resistance value of the first terminal of the connector), R ２ is defined as (the DC electrical resistance value of the first electrode) - (the DC electrical resistance value of the first conductor) - (the DC electrical resistance value of the second terminal of the connector), R １ / R ２ 3. The electrode catheter of claim 1, wherein the .lambda.-d is .ltoreq.3.

5.

7. 3. The electrode catheter according to claim 1, wherein the minimum outer diameter of the core material is greater than the minimum outer diameter of the first conductor.

8. the first terminal has a recess that receives the proximal end of the core; The electrode catheter according to claim 1 or 2, wherein a maximum inner diameter of the recess of the first terminal is greater than a maximum outer diameter of the proximal end of the core material.

9. the first terminal has a recess that receives the proximal end of the core; the second terminal has a recess for receiving the proximal end of the first conductor; 3. The electrode catheter according to claim 1, wherein the recess of the first terminal and the recess of the second terminal have the same shape.

10. 3. The electrode catheter according to claim 1, wherein the tip electrode is an electrode soldered to the core material.

11. 3. The electrode catheter according to claim 1, wherein the tip electrode is an electrode welded to the core material.

12. 3. The electrode catheter according to claim 1, wherein the core material is a stranded wire having a first wire and a second wire.

13. the core material is a stranded wire having a first wire, a second wire, and a third wire, The first wire has a tensile strength of 800 N / mm ２ the second wire is a first conductor of a thermocouple, and the third wire is a second conductor of the thermocouple, a proximal end of the first wire is connected to the first terminal; 2. The electrode catheter according to claim 1, wherein the connector further comprises a terminal to which a proximal end of the second wire is connected, and a terminal to which a proximal end of the third wire is connected.

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