High frequency treatment tools

Abstract

To provide a high frequency treatment instrument capable of changing an incision direction according to a position of a conductive wire.SOLUTION: A high frequency treatment instrument has a shaft 5 and a conductive wire 20 arranged inside the shaft 5. The conductive wire 20 has an exposure section 21 exposed outside the shaft at least in one part. A cross-sectional figure by a cross section vertical to a longitudinal axis direction of the conductive wire 20 has a short axis and a long axis. A direction of the long axis differs depending on positions of the exposure section 21.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a high-frequency treatment instrument that is introduced into a living body via an endoscope. [Background technology]

[0002] In endoscopic surgery such as endoscopic sphincterotomy (EST), a treatment tool is used to perform treatment inside a body cavity through a treatment tool insertion channel of an endoscope that extends from the proximal side to the distal side. One such treatment tool is a papillotomy knife.

[0003] For example, in the treatment tools disclosed in Patent Documents 1 to 3, a conductive wire is inserted into a sheath (shaft) that extends from the tip to the proximal side, and a part of the conductive wire is exposed to the outside at the tip side of the treatment tool. By passing a high-frequency current through the conductive wire, tissue such as a lesion can be incised at the exposed part of the conductive wire. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2004-73582 A [Patent Document 2] JP 2016-54774 A [Patent Document 3] JP 2001-79017 A Summary of the Invention [Problem to be solved by the invention]

[0005] From the viewpoint of improving the efficiency of a procedure, it is beneficial to provide a treatment tool that can change the incision direction. Therefore, an object of the present invention is to provide a high-frequency treatment tool that can change the incision direction depending on the position of the conductive wire. [Means for solving the problem]

[0006] One embodiment of the high-frequency treatment tool of the present invention that has achieved the above object includes a shaft and a conductive wire disposed in the shaft, the conductive wire has an exposed section that is at least partially exposed to the outside of the shaft, and the cross-sectional shape of the conductive wire taken along a cross section perpendicular to the longitudinal axis direction has a short axis and a long axis, and the direction of the long axis varies depending on the position of the exposed section. With the high-frequency treatment tool of the present invention, the user can change the incision direction depending on the position of the exposed section of the conductive wire that has the desired bending direction. Therefore, incisions can be made in multiple directions with one high-frequency treatment tool, making it possible to treat various lesions.

[0007] The conductive wire may have a first position within the exposed section and a second position proximal to the first position, and when the high-frequency treatment tool is viewed from the proximal side in the longitudinal direction of the shaft, the direction of the long axis of the cross-sectional shape at the first position may be tilted clockwise by 5 degrees or more from the direction of the long axis of the cross-sectional shape at the second position. The conductive wire may have a first position within the exposed section and a second position proximal to the first position, and when the high-frequency treatment tool is viewed from the proximal side in the longitudinal direction of the shaft, the direction of the long axis of the cross-sectional shape at the first position may be tilted counterclockwise by 5 degrees or more from the direction of the long axis of the cross-sectional shape at the second position.

[0008] The conductive wire may have an unexposed section disposed in the first lumen of the shaft, and the direction of the long axis of the cross-sectional shape of the conductive wire may vary depending on the position of the unexposed section. Also, the conductive wire may have an unexposed section disposed in the first lumen of the shaft, and the direction of the long axis of the cross-sectional shape of the conductive wire may be the same at any position of the unexposed section.

[0009] The conductive wire has an unexposed section disposed in a first inner cavity of the shaft, the unexposed section including a first unexposed section distal to the exposed section and a second unexposed section proximal to the exposed section, and the direction of the long axis of the cross-sectional shape of the conductive wire varies depending on its position in the first unexposed section and may be the same at any position in the second unexposed section.

[0010] The conductive wire has an unexposed section disposed in a first lumen of the shaft, the unexposed section including a first unexposed section distal to the exposed section and a second unexposed section proximal to the exposed section, the shaft has a first opening and a second opening exposing the conductive wire, the second opening is disposed proximal to the first opening, and the distal end of the second unexposed section of the conductive wire may be in contact with the first circumferential end of the second opening of the inner wall of the shaft. The distal end of the second unexposed section of the conductive wire may be in contact with the second circumferential end of the second opening of the inner wall of the shaft. The proximal end of the first unexposed section of the conductive wire may be in contact with the first circumferential end of the first opening of the inner wall of the shaft.

[0011] In a cross section perpendicular to the longitudinal axis of the shaft in the exposed section of the conductive wire, a straight line connecting the centroid of the shaft and the centroid of the conductive wire may be parallel to the minor axis of the conductive wire.

[0012] The conductive wire may have a non-exposed section disposed in a first lumen of the shaft, and a cross-sectional shape of a cross section perpendicular to the longitudinal axis of the conductive wire in the non-exposed section may be non-circular. The shaft may have a first lumen and a second lumen, and the distal end of the conductive wire may be disposed in the first lumen. In this case, the high-frequency treatment device may further have a fixture disposed at the distal end of the conductive wire and in contact with the inner wall of the first lumen. Effect of the Invention

[0013] According to the high-frequency treatment tool of the present invention, the user can change the incision direction depending on the position of the exposed section of the conductive wire having the desired bending direction. Therefore, it is possible to incise in multiple directions with one high-frequency treatment tool, and it is possible to treat various lesions. [Brief description of the drawings]

[0014] [Figure 1] 1 is a side view of a high-frequency treatment device according to an embodiment of the present invention. [Diagram 2] 2 is an enlarged cross-sectional view (partial side view) of a distal end portion of the high-frequency treatment device shown in FIG. 1. [Diagram 3]3 is a cross-sectional end view of the shaft and the conductive wire taken along line III-III in FIG. 2. [Figure 4] 4 is a cross-sectional end view of the conductive wire shown in FIG. 2 taken along line IV-IV. [Diagram 5] 3 is a cut end view of the VV line of the conductive wire shown in FIG. 2. FIG. [Figure 6] 6 is a cut end view showing a modified example of the conductive wire shown in FIG. 5. FIG. [Figure 7] 3 is a cross-sectional end view of the conductive wire taken along line VII-VII shown in FIG. 2. [Figure 8] 3 is a cross-sectional end view of the conductive wire taken along line VIII-VIII shown in FIG. 2. [Figure 9] 3 is a cross-sectional end view of the conductive wire taken along line IX-IX shown in FIG. 2. [Figure 10] 3 is a cross-sectional end view of the conductive wire taken along line XX shown in FIG. 2. [Figure 11] 10 is a cut end view showing a modified example of the conductive wire shown in FIG. 9. [Figure 12] 2 is an enlarged plan view of a distal end portion of the high-frequency treatment device shown in FIG. 1. [Figure 13] 13 is a plan view showing a modified example of the high-frequency treatment device shown in FIG. 12. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] 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.

[0016] One embodiment of the high-frequency treatment tool of the present invention has a shaft and a conductive wire disposed in the shaft, the conductive wire has an exposed section at least partially exposed to the outside of the shaft, and the cross-sectional shape of the conductive wire taken along a cross section perpendicular to the longitudinal axis direction has a short axis and a long axis, and the direction of the long axis varies depending on the position of the exposed section. With the high-frequency treatment tool of the present invention, the user can change the incision direction depending on the position of the exposed section of the conductive wire having the desired bending direction. Therefore, incisions can be made in multiple directions with one high-frequency treatment tool, making it possible to treat various lesions.

[0017] A high-frequency treatment tool is introduced into a body cavity via a treatment tool insertion channel of an endoscope and is used in a procedure such as EST. Hereinafter, the high-frequency treatment tool may be simply referred to as a treatment tool. A configuration example of a high-frequency treatment tool will be described with reference to Figs. 1 to 13. Fig. 1 is a side view of a high-frequency treatment tool according to an embodiment of the present invention. Fig. 2 is an enlarged cross-sectional view (partial side view) of the distal end of the high-frequency treatment tool shown in Fig. 1. Fig. 3 is a cut end view of the shaft and conductive wire shown in Fig. 2 taken along line III-III. Figs. 4 to 5 and Figs. 7 to 10 are cut end views of the conductive wire shown in Fig. 2, respectively. Figs. 6 and 11 are cut end views showing modified conductive wires. Fig. 12 is an enlarged plan view of the distal end of the high-frequency treatment tool shown in Fig. 1. Fig. 13 is a plan view showing a modified high-frequency treatment tool shown in Fig. 12. Note that the third opening 16 and the fifth opening are omitted in Figs. 12 to 13. The treatment tool 1 has a shaft 5 and a conductive wire 20.

[0018] 1, the treatment tool 1 has an insertion section 2 that is inserted into a treatment tool insertion channel of an endoscope, and a handle 65 connected to the proximal side of the insertion section 2. A curved section 3 may be provided at the distal end of the insertion section 2 to facilitate insertion into a body cavity such as the papilla. The handle 65 may be capable of changing the degree of curvature of the distal section of the shaft 5 and the curved section 3. The configuration on the hand side for moving the treatment tool 1 will be described later.

[0019] The distal side of the treatment tool 1 refers to the distal end side of the shaft 5 in the longitudinal axis direction x, which is the side to be treated. The proximal side of the treatment tool 1 refers to the proximal end side of the shaft 5 in the longitudinal axis direction x, which is the side closest to the user. When each member is divided in half in its longitudinal axis direction, the proximal side may be referred to as the proximal portion, and the distal side may be referred to as the distal portion. The inside and outside of the shaft 2 refer to the inside and outside in the radial direction of the shaft 5, and the inside in the radial direction of the shaft 5 refers to the side closer to the center of the longitudinal axis of the shaft 5.

[0020] The shaft 5 is a long member having a longitudinal axis direction x, a radial direction, and a circumferential direction p. The shaft 5 has a distal end and a proximal end in the longitudinal axis direction x. Since the conductive wire 20 is disposed inside the shaft 5, the shaft 5 preferably has a cylindrical structure. The shaft 5 preferably has one or more internal cavities, and the internal cavities preferably extend in the longitudinal axis direction x of the shaft 5.

[0021] 2 and 3, the shaft 5 has a first lumen 11 and a second lumen 12. The tip of the conductive wire 20 is disposed in the first lumen 11. The second lumen 12 can be used as a passage for a guidewire or a flow path for a liquid to be injected into a body cavity. Examples of the liquid include physiological saline, hyaluronic acid solution, contrast agent, and liquids containing medicines or cells.

[0022] 3, the shaft 5 may have a third lumen 13. In that case, the second lumen 12 may be used as a passage for inserting a guidewire, and the third lumen 13 may be used as a flow path for a liquid to be injected into a body cavity. The first lumen 11 may extend from the distal end to the proximal end of the shaft 5, and the distal end of the first lumen 11 may be located proximal to the distal end of the shaft 5.

[0023] The shaft 5 has one or more openings for exposing the conductive wire 20. The openings communicate with the lumen of the shaft 5. In Figs. 1 and 2, the shaft 5 has a first opening 14 and a second opening 15 in this order from the distal side on the outer circumferential surface of the distal part, and the first lumen 11 communicates with the outside of the shaft 5 through the first opening 14 and the second opening 15. The conductive wire 20 may be exposed using a plurality of openings in this manner, but the conductive wire 20 may also be exposed from one opening. For example, the shaft 5 may have an opening extending in the longitudinal axis direction of the shaft 5 on the outer circumferential surface of the distal part, and the conductive wire 20 may be exposed from the opening.

[0024] In Fig. 2, the shaft 5 has a tapered portion 8 at its distal end, the outer diameter of which decreases toward the distal end. The tapered portion 8 makes it easier for the treatment tool 1 to pass through the body. The tapered portion 8 is preferably located distal to the first opening 14.

[0025] The shaft 5 may have an opening for a purpose other than exposing the conductive wire 20. The shaft 5 may have at least one of a third opening 16 communicating with the first lumen 11, a fourth opening 17 communicating with the second lumen 12 and allowing a guide wire to protrude, and a fifth opening communicating with the third lumen 13 and releasing a fluid into a body cavity. At least one of the third opening 16, the fourth opening 17, and the fifth opening may be disposed in the tapered portion 8. At least one of the third opening 16, the fourth opening 17, and the fifth opening is preferably located distal to the first opening 14.

[0026] The shaft 5 is preferably flexible. This allows the shaft 5 to be deformed according to the shape of the body cavity. In order to maintain the shape, the shaft 5 is preferably elastic. The shaft 5 is preferably made of resin, metal, or a combination of resin and metal. Examples of the shaft 5 include a resin tube; a metal tube; a hollow body formed by arranging wires in a predetermined pattern; a hollow body in which at least one of the inner surface or outer surface is coated with resin; or a combination of these, for example, a combination of these, for example, a combination of these connected in the longitudinal direction. The resin tube can be manufactured by, for example, extrusion molding. Examples of the hollow body in which the wires are arranged in a predetermined pattern include a cylindrical body having a mesh structure formed by simply crossing or weaving the wires, and a coil in which the wires are wound. The wires may be one or more solid wires, or one or more twisted wires. The cross-sectional shape of the wires may be, for example, a circle, an oval, a polygon, or a combination of these. The oval shape includes an ellipse, an egg, and a rounded rectangle, and the same applies in the following description. The type of the mesh structure is not particularly limited, and the number of turns and density of the coil are also not particularly limited. The mesh structure and the coil may be formed with a constant density over the entire longitudinal axis direction x of the shaft 5, or may be formed so that the density varies depending on the position in the longitudinal axis direction x of the shaft 5. In order to increase the flexibility of the metal tube, a cut or groove may be formed on the outer surface of the metal tube. The shape of the cut or groove may be linear, arc-shaped, annular, spiral, or a combination of these. When the shaft 5 is a cylindrical resin tube, the shaft 5 may be composed of a single layer or multiple layers, and a part in the longitudinal axis direction x or circumferential direction p may be composed of a single layer, and the other part may be composed of multiple layers.

[0027] The cross-sectional shape of the shaft 5 perpendicular to the longitudinal axis direction x is not particularly limited, and may be, for example, a circle, an ellipse, a polygon, or a combination of these.

[0028] The conductive wire 20 is disposed in the shaft 5. By passing a high-frequency current through the conductive wire 20, the conductive wire 20 can be used as a knife part of a high-frequency knife. This makes it possible to incise biological tissue and remove tissue such as a diseased part. The conductive wire 20 has a tip and a base end in its longitudinal axis direction. The conductive wire 20 extends as a whole from the distal side to the proximal side of the shaft 5. The tip of the conductive wire 20 is fixed to the shaft 5 so that the conductive wire 20 does not come off the shaft 5 during the procedure. A detailed method of fixing the tip of the conductive wire 20 to the shaft 5 will be described later. The base end of the conductive wire 20 is connected to a high-frequency power source so that electrical conductivity is ensured. In addition, the base end of the conductive wire 20 is connected to a handle 65.

[0029] The conductive wire 20 has an exposed section 21, at least a part of which is exposed to the outside of the shaft 5. The exposed section 21 is disposed between the tip and base ends of the conductive wire 20. In FIG. 2, the part exposed from the first opening 14 and the second opening 15 of the shaft 5 is the exposed section 21. The exposed section 21 is preferably a part of the tip of the conductive wire 20. The length and degree of bending of the exposed section 21 can be changed by operating the handle 65 to move the conductive wire 20 back and forth, and the shape of the knife can be changed according to the procedure. The shape of the conductive wire 20 in the exposed section 21 is not particularly limited, and may be, for example, a loop shape or a half loop shape.

[0030] In FIG. 2, the conductive wire 20 has a non-exposed section 22 arranged in the first lumen 11 of the shaft 5. The non-exposed section 22 may include a first non-exposed section 221 located distal to the exposed section 21 and a second non-exposed section 222 located proximal to the exposed section 21. The exposed section 21 may be shorter than the non-exposed section 22. The conductive wire 20 may have an insulating layer on its surface to maintain electrical insulation. The insulating layer of the conductive wire 20 may be arranged not only in the non-exposed section 22 of the conductive wire 20 but also in a part of the exposed section 21 in order to prevent electrical current from being applied to and incised by the endoscope or unintended tissue. The part of the exposed section 21 without the insulating layer functions as a knife section.

[0031] The shape of the cross section perpendicular to the longitudinal axis direction of the conductive wire 20 is not particularly limited and may be a circle, an oval, a polygon, or a combination of these, but is preferably a non-circular shape. The cross section perpendicular to the longitudinal axis direction of the conductive wire 20 may be the same throughout the entire longitudinal axis direction of the conductive wire 20, or may differ depending on the position of the exposed section 21 or the unexposed section 22. The cross section may have only straight line portions 25, may have only curved line portions 26, or may have both straight line portions 25 and curved line portions 26 as shown in FIG. 4.

[0032] The conductive wire 20 is preferably made of an elastically deformable material. The conductive wire 20 may be made of any conductive material, such as a superelastic alloy such as a Ni-Ti alloy, or stainless steel such as SUS303, SUS304, or SUS316. The conductive wire 20 may be made of one member, or may be made by joining multiple members midway along the longitudinal axis. As a joining method, in addition to a method of crimping the ends of multiple members with a ring member such as a metal tube, welding, adhesion, etc. can be used. The conductive wire 20 may be a solid wire, or a twisted wire made by twisting together single wires.

[0033] 4 and 5, a cross-sectional shape of conductive wire 20 taken along a cross section perpendicular to the longitudinal axis has minor axis 23 and major axis 24, and the direction of major axis 24 of the cross-sectional shape varies depending on the position of exposed section 21. With treatment tool 1, the user can change the incision direction depending on the position in exposed section 21 of conductive wire 20 having a desired bending direction. Therefore, incisions can be made in multiple directions with one treatment tool 1, making it possible to treat various lesions.

[0034] In the present invention, the direction of long axis 24 of the cross-sectional shape of conductive wire 20 differs depending on the position of exposed section 21 means that when the cross-sectional shapes are observed at two different positions in the longitudinal axis direction of conductive wire 20, the directions of long axis 24 of the two cross-sectional shapes are non-parallel. The description later that the direction of long axis 24 of the cross-sectional shape of conductive wire 20 differs depending on the position of unexposed section 22 can be interpreted in a similar manner.

[0035] The conductive wire 20 has a first position 41 and a second position 42 located closer to the first position 41 in the exposed section 21. The cross-sectional shape of the conductive wire 20 at the first position 41 is shown in FIG. 4, and the cross-sectional shape of the conductive wire 20 at the second position 42 is shown in FIG. 5. The first position 41 and the second position 42 can be set at any two positions in the exposed section 21. When the exposed section 21 of the conductive wire 20 is divided into two equal parts in the longitudinal direction of the shaft 5, the section on the distal side is the first exposed section 211, and the section on the proximal side is the second exposed section 212. In this case, the first position 41 may be located in the first exposed section 211, and the second position 42 may be located in the second exposed section 212. Also, the first position 41 and the second position 42 may be located in the first exposed section 211, and the first position 41 and the second position 42 may be located in the second exposed section 212.

[0036] The direction of the long axis 24 of the cross-sectional figure at the first position 41 may be different from the direction of the long axis 24 of the cross-sectional figure at the second position 42. The inclination angle of the direction of the long axis 24 of the cross-sectional figure at the first position 41 with respect to the direction of the long axis 24 of the cross-sectional figure at the second position 42 is not particularly limited. For example, as shown in Figs. 4 to 5, when the treatment tool 1 is viewed from the proximal side of the longitudinal axis direction x of the shaft 5, it is preferable that the direction of the long axis 24 of the cross-sectional figure at the first position 41 is inclined clockwise by 5 degrees or more than the direction of the long axis 24 of the cross-sectional figure at the second position 42. By arranging the conductive wire 20 so that it is twisted clockwise when viewed from the proximal side, incision can be easily performed. Note that the direction of the long axis 24 in Fig. 4 is inclined clockwise by 40 degrees compared to Fig. 5.

[0037] When the treatment tool 1 is viewed from the proximal side of the longitudinal axis direction x of the shaft 5, the direction of the long axis 24 of the cross-sectional figure at the first position 41 may be inclined clockwise by 10 degrees or more, or by 20 degrees or more, or by 180 degrees or less, or by 150 degrees or less, or by 120 degrees or less, relative to the direction of the long axis 24 of the cross-sectional figure at the second position 42.

[0038] Fig. 6 shows a modified example of the cross-sectional shape at the second position 42. As shown in Fig. 6, when the treatment tool 1 is viewed from the proximal side of the longitudinal axis direction x of the shaft 5, it is preferable that the direction of the long axis 24 of the cross-sectional shape at the first position 41 is tilted counterclockwise by 5 degrees or more from the direction of the long axis 24 of the cross-sectional shape at the second position 42. The incision direction can also be adjusted by arranging the conductive wire 20 so that it is twisted counterclockwise when viewed from the proximal side. Note that in Fig. 4, the direction of the long axis 24 is tilted counterclockwise by 20 degrees compared to Fig. 6.

[0039] When the treatment tool 1 is viewed from the proximal side of the longitudinal axis direction x of the shaft 5, the direction of the long axis 24 of the cross-sectional shape at the first position 41 may be inclined counterclockwise by 10 degrees or more, 20 degrees or more, or may be inclined less than 180 degrees, 150 degrees or less, or 120 degrees or less than. In this specification, when the direction of the long axis 24 of the cross-sectional shape at the first position 41 is inclined more than 0 degrees and 180 degrees or less than the direction of the long axis 24 of the cross-sectional shape at the second position 42, it is expressed as clockwise, and when it is inclined more than 180 degrees and less than 360 degrees, it is expressed as counterclockwise. Therefore, inclining 181 degrees clockwise and inclining 179 degrees counterclockwise are synonymous, but in this case, it is expressed as counterclockwise.

[0040] The conductive wire 20 may also be twisted in the first lumen 11. For example, as shown in Figures 2 and 7 to 10, the conductive wire 20 has a non-exposed section 22 disposed in the first lumen 11 of the shaft 5, and the direction of the long axis 24 of the cross-sectional shape of the conductive wire 20 may vary depending on the position of the non-exposed section 22. By twisting the conductive wire 20 in this way also in the non-exposed section 22, it becomes easier to adjust the bending direction of the conductive wire 20 so that the exposed section 21 can be easily incised.

[0041] The unexposed section 22 includes a first unexposed section 221 distal to the exposed section 21 and a second unexposed section 222 proximal to the exposed section 21. The conductive wire 20 has a third position 43 in the first unexposed section 221 and a fourth position 44 proximal to the third position 43, and has a fifth position 45 in the second unexposed section 222 and a sixth position 46 proximal to the fifth position 45. The cross-sectional shape of the conductive wire 20 at the third position 43 is shown in FIG. 7, the cross-sectional shape of the conductive wire 20 at the fourth position 44 is shown in FIG. 8, the cross-sectional shape of the conductive wire 20 at the fifth position 45 is shown in FIG. 9, and the cross-sectional shape of the conductive wire 20 at the sixth position 46 is shown in FIG. 10.

[0042] The third position 43 and the fourth position 44 can be set at any two positions within the first unexposed section 221. The third position 43 is preferably located on the base end side of the tip of the conductive wire 20. Furthermore, when a fixture 50 is disposed at the tip of the conductive wire 20, the third position 43 is preferably located on the proximal side of the fixture 50.

[0043] The fifth position 45 and the sixth position 46 can be set to any two positions within the second unexposed section 222. The sixth position 46 is preferably located closer to the tip side than the base end of the conductive wire 20. In addition, the sixth position 46 is preferably located at the curved portion 3 of the shaft 5.

[0044] 7 and 8, when the treatment tool 1 is viewed from the proximal side of the longitudinal axis direction x of the shaft 5, the direction of the long axis 24 of the cross-sectional shape at the third position 43 may be inclined clockwise by 5 degrees or more, 10 degrees or more, 20 degrees or more, 90 degrees or less, 60 degrees or less, or 45 degrees or less than the direction of the long axis 24 of the cross-sectional shape at the fourth position 44. Note that the direction of the long axis 24 in FIG. 7 is inclined 15 degrees clockwise compared to FIG. 8.

[0045] When the treatment tool 1 is viewed from the proximal side of the longitudinal axis direction x of the shaft 5, the direction of the long axis 24 of the cross-sectional shape at the third position 43 may be inclined counterclockwise by 5 degrees or more, 10 degrees or more, 20 degrees or more, 90 degrees or less, 60 degrees or less, or 45 degrees or less than the direction of the long axis 24 of the cross-sectional shape at the fourth position 44.

[0046] The direction of the long axis 24 of the cross-sectional shape of the conductive wire 20 may be the same at any position in the first unexposed section 221. For example, when the treatment tool 1 is viewed from the proximal side in the longitudinal axis direction x of the shaft 5, the direction of the long axis 24 of the cross-sectional shape at the third position 43 may be the same as the direction of the long axis 24 of the cross-sectional shape at the fourth position 44.

[0047] 9 and 10, when the treatment tool 1 is viewed from the proximal side of the longitudinal axis direction x of the shaft 5, the direction of the long axis 24 of the cross-sectional shape at the fifth position 45 may be inclined clockwise by 5 degrees or more, 10 degrees or more, 20 degrees or more, 90 degrees or less, 60 degrees or less, or 45 degrees or less than the direction of the long axis 24 of the cross-sectional shape at the sixth position 46. Note that the direction of the long axis 24 in FIG. 9 is inclined 15 degrees clockwise compared to FIG. 10.

[0048] When the treatment tool 1 is viewed from the proximal side in the longitudinal direction x of the shaft 5, the direction of the long axis 24 of the cross-sectional shape at the fifth position 45 may be inclined counterclockwise by 5 degrees or more, 10 degrees or more, 20 degrees or more, 90 degrees or less, 60 degrees or less, or 45 degrees or less than the direction of the long axis 24 of the cross-sectional shape at the sixth position 46.

[0049] The direction of the long axis 24 of the cross-sectional shape of the conductive wire 20 may be the same at any position in the second unexposed section 222. For example, when the treatment tool 1 is viewed from the proximal side in the longitudinal axis direction x of the shaft 5, the direction of the long axis 24 of the cross-sectional shape at the fifth position 45 may be the same as the direction of the long axis 24 of the cross-sectional shape at the sixth position 46.

[0050] The conductive wire 20 may be twisted in a part of the non-exposed section 22, and may not be twisted in the remaining section of the non-exposed section 22. FIG. 11 shows a modified example of the cross-sectional shape at the fifth position 45. The direction of the long axis 24 of the cross-sectional shape of the conductive wire 20 may be different depending on the position in the first non-exposed section 221, and may be the same at any position in the second non-exposed section 222. For example, in FIGS. 7 to 8, the direction of the long axis 24 of the cross-sectional shape at the third position 43 is inclined 15 degrees clockwise with respect to the direction of the long axis 24 of the cross-sectional shape at the fourth position 44. As shown in FIGS. 10 and 11, the directions of the long axis 24 of the cross-sectional shape of the conductive wire 20 at the fifth position 45 and the sixth position 46 extend in the vertical direction of the paper and are consistent. With this configuration, the bending direction of the conductive wire 20 can be adjusted so that the exposed section 21 can be easily incised.

[0051] The conductive wire 20 does not have to be twisted in the first lumen 11. The direction of the long axis 24 of the cross-sectional shape of the conductive wire 20 may be the same at any position in the unexposed section 22. This configuration also makes it possible to adjust the bending direction of the conductive wire 20. In detail, the direction of the long axis 24 of the cross-sectional shape of the conductive wire 20 may be the same at any position in the first unexposed section 221 and also at any position in the second unexposed section 222.

[0052] The direction of the long axis 24 of the cross-sectional shape of the conductive wire 20 in the first exposed section 211 may be different from the direction of the long axis 24 of the cross-sectional shape of the conductive wire 20 in the first unexposed section 221. In addition, the direction of the long axis 24 of the cross-sectional shape of the conductive wire 20 in the second exposed section 212 may be different from the direction of the long axis 24 of the cross-sectional shape of the conductive wire 20 in the second unexposed section 222.

[0053] The direction of the long axis 24 of the cross-sectional shape of the conductive wire 20 in the first exposed section 211 may be the same as the direction of the long axis 24 of the cross-sectional shape of the conductive wire 20 in the first unexposed section 221. Also, the direction of the long axis 24 of the cross-sectional shape of the conductive wire 20 in the second exposed section 212 may be the same as the direction of the long axis 24 of the cross-sectional shape of the conductive wire 20 in the second unexposed section 222.

[0054] It is preferable that the conductive wire 20 is twisted at least in the exposed section 21 so that the conductive wire 20 contacts the inner wall 6 of the shaft 5 at the opening. For example, as shown in FIG. 12, the shaft 5 has a first opening 14 and a second opening 15 that expose the conductive wire 20, and the second opening 15 is disposed closer to the first opening 14. In the circumferential direction p of the shaft 5, the first opening 14 has a first end 141 and a second end 142, and the second opening 15 also has a first end 151 and a second end 152. In this case, it is preferable that the distal end of the second non-exposed section 222 of the conductive wire 20 contacts the first end 151 side of the second opening 15 of the inner wall 6 of the shaft 5 in the circumferential direction p. By disposing the conductive wire 20 in this manner, the bending direction of the conductive wire 20 can be adjusted so that the exposed section 21 can be easily incised.

[0055] In order to adjust the bending direction of the conductive wire 20 in the exposed section 21, the length of the first opening 14 and the length of the second opening 15 may be different in the circumferential direction p of the shaft 5. Also, the first end 141 of the first opening 14 and the first end 151 of the second opening 15 may be located at different positions in the circumferential direction p of the shaft 5. Similarly, the second end 142 of the first opening 14 and the second end 152 of the second opening 15 may be located at different positions in the circumferential direction p of the shaft 5.

[0056] 12 , a proximal end of the first unexposed section 221 of the conductive wire 20 may be in contact with the first end 141 side in the circumferential direction p of the first opening 14 of the inner wall 6 of the shaft 5. By arranging the conductive wire 20 in this manner, the bending direction of the conductive wire 20 can be adjusted so that the exposed section 21 can be easily incised.

[0057] 13, it is preferable that the distal end of the second unexposed section 222 of the conductive wire 20 contacts the second end 152 side in the circumferential direction p of the second opening 15 of the inner wall 6 of the shaft 5. By arranging the conductive wire 20 in this manner, the bending direction of the conductive wire 20 can also be adjusted.

[0058] When the shaft 5 does not have the second opening 15 and the conductive wire 20 is exposed only from the first opening 14, the distal end or proximal end of the unexposed section 22 of the conductive wire 20 may be in contact with the inner wall 6 of the shaft 5 as follows. The distal end of the second unexposed section 221 of the conductive wire 20 may be in contact with the first end 141 side of the first opening 14 of the inner wall 6 of the shaft 5 in the circumferential direction p. The distal end of the second unexposed section 222 of the conductive wire 20 may be in contact with the second end 142 side of the first opening 14 of the inner wall 6 of the shaft 5 in the circumferential direction p. The proximal end of the first unexposed section 221 of the conductive wire 20 may be in contact with the first end 141 side of the first opening 14 of the inner wall 6 of the shaft 5 in the circumferential direction p.

[0059] As shown in Fig. 3, in a cross section perpendicular to the longitudinal axis direction x of the shaft 5 in the exposed section 21 of the conductive wire 20, it is preferable that the short axis 23 of the conductive wire 20 is parallel to a straight line connecting the centroid 19 of the shaft 5 and the centroid 27 of the conductive wire 20. By using the conductive wire 20 having such a cross section, it is possible to arrange the conductive wire 20 in a direction away from the shaft 5. The centroid refers to a point at which a figure is balanced when the weight acts uniformly and the position is used as a fulcrum. The centroid coincides with the center of gravity when the shape of the cross section perpendicular to the longitudinal axis direction x is a uniform plate.

[0060] At the midpoint of the exposed section 21 of the conductive wire 20, in a cross section perpendicular to the longitudinal axis direction x of the shaft 5, it is preferable that the straight line connecting the centroid 19 of the shaft 5 and the centroid 27 of the conductive wire 20 is parallel to the short axis 23 of the conductive wire 20. The midpoint of the exposed section 21 means the midpoint in the longitudinal direction of the conductive wire 20 when the conductive wire 20 is exposed from the shaft 5 so that the exposed portion is at its longest. For example, when the length of the conductive wire 20 is longer than the shaft 5 and the conductive wire 20 is curved within the inner cavity of the shaft 5, the length of the exposed portion of the conductive wire 20 in the natural state may be shorter than the length of the conductive wire 20 when the conductive wire 20 is exposed from the shaft 5 by, for example, pulling the conductive wire 20 in the radial direction so that the exposed portion is at its longest.

[0061] A detailed method of fixing the tip of the conductive wire 20 to the shaft 5 will be described. The tip of the conductive wire 20 may be directly fixed to the shaft 5, or may be indirectly fixed via another member. In FIG. 2, a fixture 50 is disposed at the tip of the conductive wire 20. In this case, it is preferable that the fixture 50 contacts the inner wall of the first lumen 11 of the shaft 5. Since the fixture 50 contacts the inner wall of the first lumen 11, frictional resistance is generated, and therefore the conductive wire 20 can be prevented from coming off the shaft 5 when the conductive wire 20 is advanced or retreated.

[0062] The fixture 50 has a tip and a base. The tip of the fixture 50 is located on the tip side of the conductive wire 20, and the direction from the tip to the base of the fixture 50 coincides with the direction from the tip to the base of the conductive wire 20. The shape of the fixture 50 is not particularly limited, and may be, for example, a rectangular column, a cylindrical column, an oblong cylindrical column, or a combination of these. The fixture 50 may have a portion whose outer diameter decreases toward the tip. Examples of such shapes include truncated pyramid shapes, such as a truncated cone shape, a truncated cone shape, an oblong truncated cone shape, and a truncated cone shape with rounded corners.

[0063] Fixture 50 can be made of the same resin as shaft 5 or the same metal as conductive wire 20. Fixture 50 can also contain an X-ray impermeable material. The method of fixing fixture 50 to conductive wire 20 is not particularly limited, but methods such as crimping, fusing, welding, and adhesion can be used.

[0064] When the conductive wire 20 has a non-exposed section 22 disposed in the first lumen 11, the cross-sectional shape of the conductive wire 20 perpendicular to the longitudinal axis direction in the non-exposed section 22 is preferably non-circular, for example, as shown in Figs. 7 to 10. In particular, the cross-sectional shape of the conductive wire 20 perpendicular to the longitudinal axis direction x in the first non-exposed section 221 is preferably non-circular. By making the cross-sectional shape like this, frictional resistance occurs between the conductive wire 20 and the shaft 5 or the fixture 50, so that the conductive wire 20 can be prevented from rotating relative to the shaft 5 or the fixture 50. The cross-sectional shapes of the conductive wire 20 in the exposed section 21 and the non-exposed section 22 may be the same or different from each other.

[0065] In FIG. 1, the handle 65 has a first handle 66 connected to the base end of the conductive wire 20 and a second handle 68 connected to the proximal side of the shaft 5. The first handle 66 is arranged outside the second handle 68, but the second handle 68 may be arranged outside the first handle 66. The first handle 66 is configured to be movable relative to the second handle 68. By moving the first handle 66, the length and degree of bending of the exposed section 21 can be changed. The shaft 5 and the second handle 68 are connected via a connecting tube 60, and the tube 60 has a first introduction port 61 for inserting a guide wire. The second handle 68 has a second introduction port 67 for introducing a liquid into the second lumen 12 or the third lumen 13 of the shaft 5. The first handle 66 has a connection portion 69 with a high-frequency power source. The shaft 5 and the second handle 68, or the conductive wire 20 and the first handle 66 may be directly connected to each other, or may be connected via another member such as the tube 60. These can be connected by a method such as thermocompression bonding or bonding with an adhesive. [Explanation of symbols]

[0066] 1: High frequency treatment tool 5: Shaft 20: Conductive wire 21: Exposure section 22: Unexposed section 23:Short axis 24:Long axis 41: 1st position 42: 2nd position 50: Fixture x: longitudinal direction of shaft p: Circumferential direction of shaft

Claims

1. The electromechanical device has a shaft and a conductive wire disposed within the shaft, The shaft has a first opening and a second opening in order from the distal side on an outer circumferential surface of a distal portion thereof, the conductive wire has an exposed section exposed to the outside of the shaft through the first opening and the second opening, a cross-sectional shape of the conductive wire taken along a cross section perpendicular to a longitudinal axis direction has a minor axis and a major axis, and a direction of the major axis varies depending on a position of the exposed section; A high-frequency treatment tool in which a tip portion of the conductive wire is fixed to the shaft.

2. A high-frequency treatment instrument as described in claim 1, wherein, when the high-frequency treatment instrument is viewed from the proximal side in the longitudinal axis direction of the shaft, the conductive wire is twisted clockwise from the proximal side to the distal side in the exposed section.

3. A high-frequency treatment device as described in claim 1, wherein, when the high-frequency treatment device is viewed from the proximal side in the longitudinal axis direction of the shaft, the conductive wire is twisted counterclockwise from the proximal side to the distal side in the exposed section.

4. the conductive wire has an unexposed section disposed in a first lumen of the shaft; 4. The high-frequency treatment tool according to claim 1, wherein a direction of the major axis of the cross-sectional shape of the conductive wire varies depending on a position of the unexposed section.

5. the conductive wire has an unexposed section disposed in a first lumen of the shaft; 4. The high-frequency treatment tool according to claim 1, wherein the direction of the major axis of the cross-sectional shape of the conductive wire is the same at any position in the unexposed section.

6. the conductive wire has an unexposed section disposed in a first lumen of the shaft; The non-exposed section includes a first non-exposed section distal to the exposed section and a second non-exposed section proximal to the exposed section, The high-frequency treatment device according to any one of claims 1 to 3, wherein the direction of the long axis of the cross-sectional shape of the conductive wire varies depending on its position in the first non-exposed section, and is the same at any position in the second non-exposed section.

7. the conductive wire has an unexposed section disposed in a first lumen of the shaft; The non-exposed section includes a first non-exposed section distal to the exposed section and a second non-exposed section proximal to the exposed section, The high-frequency treatment instrument according to any one of claims 1 to 6, wherein a distal end of the second unexposed section of the conductive wire is in contact with a first circumferential end side of the second opening in the inner wall of the shaft.

8. the conductive wire has an unexposed section disposed in a first lumen of the shaft; The non-exposed section includes a first non-exposed section distal to the exposed section and a second non-exposed section proximal to the exposed section, The high-frequency treatment instrument according to any one of claims 1 to 6, wherein a distal end of the second unexposed section of the conductive wire is in contact with a second circumferential end side of the second opening in the inner wall of the shaft.

9. 9. The high-frequency treatment instrument according to claim 7, wherein a proximal end of the first unexposed section of the conductive wire is in contact with a first circumferential end side of the first opening in an inner wall of the shaft.

10. The high-frequency treatment device according to any one of claims 1 to 9, wherein in a cross section perpendicular to the longitudinal axis direction of the shaft in the exposed section of the conductive wire, a straight line connecting the centroid of the shaft and the centroid of the conductive wire is parallel to a short axis of the conductive wire.

11. the conductive wire has an unexposed section disposed in a first lumen of the shaft; The high-frequency treatment tool according to any one of claims 1 to 10, wherein a cross section perpendicular to a longitudinal axis direction of the conductive wire in the unexposed section has a non-circular shape.

12. The high-frequency treatment instrument according to any one of claims 1 to 11, wherein the shaft has a first inner cavity and a second inner cavity, and a tip portion of the conductive wire is disposed in the first inner cavity.

13. The high-frequency treatment tool according to claim 12, further comprising a fixture disposed at a tip end of the conductive wire and in contact with an inner wall of the first cavity.

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