Electrode unit and endoscope system

Abstract

The electrode unit includes: an electrode supporting portion; an electrode protruding from the surface of the electrode supporting portion; a base end hard portion connected to the base end of the electrode supporting portion; and an electrical connection portion, which is arranged on the base end hard portion and is electrically connected to the electrode. The electrode supporting portion includes: one or two front end hard portions, whose surfaces are covered with an electrically insulating material to hold the electrode; and one or two elastic regions, which connect the front end hard portion and the base end hard portion and have a lower bending rigidity than the bending rigidity of the front end hard portion and the base end hard portion. The electrode includes: a pair of bases, which are supported by the front end hard portion at two points on the surface of the front end hard portion that are separated from each other; and a mounting portion, which connects the pair of bases in a state separated from the surface of the front end hard portion.

Description

Technical Field

[0001] The present invention relates to an electrode unit and an endoscope system for cutting or coagulating tissue in a subject using a high-frequency current. Background Art

[0002] As a technique for cutting or coagulating tissue of a human body or other subject, an electric scalpel is known. For example, Japanese Patent No. 3730796 discloses a device for cutting or coagulating tissue in a subject using a high-frequency current under endoscopic observation. In the technique disclosed in Japanese Patent No. 3730796, a high-frequency current is passed through an electrode formed in a ring shape to cut or coagulate tissue.

[0003] The ring-shaped electrode disclosed in Japanese Patent No. 3730796 is used, for example, to remove tissue in an organ such as a bladder. Here, the depth to which the electrode enters the wall of the organ varies depending on the strength of the force with which the user presses the electrode against the wall. Therefore, when using a conventional ring-shaped electrode to remove tissue, the thickness of the removed tissue may vary due to the increase or decrease in the force applied by the user. For example, when the removed tissue is used for a biopsy, a tissue of a specified thickness is required, and therefore it is preferred that the thickness of the removed tissue is constant regardless of the user.

[0004] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an electrode unit and an endoscope system that can easily control the thickness of a tissue to be removed. Summary of the invention

[0005] Means for solving problems

[0006] An electrode unit of one embodiment of the present invention uses high-frequency current to remove or coagulate tissue in a subject, and the electrode unit includes an electrode supporting portion and an electrode, the electrode supporting portion including: a pair of front end hard portions, whose surfaces are covered with an electrically insulating material; and an elastic region portion, which is arranged on the base end side of each of the pair of front end hard portions and has a lower bending rigidity than the bending rigidity of each of the front end hard portions of the pair of front end hard portions, and the electrode includes: an electrode body, which protrudes downward from each of the front end hard portions of the pair of front end hard portions; and a mounting portion, which is mounted between the lower ends of each electrode body.

[0007] Furthermore, an endoscope system according to one aspect of the present invention includes the electrode unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a diagram showing a schematic configuration of an endoscope system according to the first embodiment.

[0009] Figure 2This is a diagram of the electrode unit according to the first embodiment viewed along the first axis.

[0010] Figure 3 This is a diagram of the electrode unit according to the first embodiment viewed along the second axis.

[0011] Figure 4 This is a diagram of the electrode unit according to the first embodiment as viewed from the distal end side along the longitudinal axis.

[0012] Figure 5 yes Figure 3 VV cross-sectional view.

[0013] Figure 6 yes Figure 5 VI-VI sectional view.

[0014] Figure 7 This is a diagram showing a first method of excising tissue using the electrode unit according to the first embodiment.

[0015] Figure 8 This is a diagram showing a first method of excising tissue using the electrode unit according to the first embodiment.

[0016] Fig. 9 This is a diagram showing a first method of excising tissue using the electrode unit according to the first embodiment.

[0017] Fig.10 This is a diagram showing a second method of excising tissue using the electrode unit of the first embodiment.

[0018] Fig.11 This is a diagram showing a second method of excising tissue using the electrode unit of the first embodiment.

[0019] Fig.12 This is a diagram showing a second method of excising tissue using the electrode unit of the first embodiment.

[0020] Fig.13 This is a diagram of a first modification example of the electrode unit according to the first embodiment as viewed along the first axis.

[0021] Fig.14 This is a diagram of a first modification of the electrode unit according to the first embodiment as viewed along the second axis.

[0022] Fig.15 This is a diagram of a first modification of the electrode unit according to the first embodiment as viewed from the distal end side along the longitudinal axis.

[0023] Fig.16 This is a diagram of a second modification of the electrode unit according to the first embodiment as viewed along the first axis.

[0024] Fig.17This is a diagram of a second modification of the electrode unit according to the first embodiment as viewed along the second axis.

[0025] Fig.18 This is a diagram of a second modification of the electrode unit according to the first embodiment as viewed from the distal end side along the longitudinal axis.

[0026] Fig.19 This is a diagram of a third modification example of the electrode unit according to the first embodiment as viewed along the first axis.

[0027] Fig. 20 This is a diagram of a third modification example of the electrode unit according to the first embodiment as viewed along the second axis.

[0028] Fig.21 This is a diagram of a third modification of the electrode unit of the first embodiment as viewed from the distal end side along the longitudinal axis.

[0029] Fig. 22 This is a diagram of a fourth modification of the electrode unit according to the first embodiment as viewed along the first axis.

[0030] Fig.23 This is a diagram of a fourth modification of the electrode unit according to the first embodiment as viewed along the second axis.

[0031] Fig.24 This is a diagram of a fourth modification of the electrode unit of the first embodiment as viewed from the distal end side along the longitudinal axis.

[0032] Fig.25 This is a diagram of a fifth modification of the electrode unit according to the first embodiment as viewed along the first axis.

[0033] Fig.26 This is a diagram of a fifth modification of the electrode unit according to the first embodiment as viewed along the second axis.

[0034] Fig. 27 This is a diagram of a fifth modification of the electrode unit of the first embodiment as viewed from the distal end side along the longitudinal axis.

[0035] Fig.28 This is a diagram of a sixth modification of the electrode unit according to the first embodiment as viewed along the first axis.

[0036] Fig.29 This is a diagram of a sixth modification of the electrode unit according to the first embodiment as viewed along the second axis.

[0037] Fig.30 This is a diagram of a sixth modification of the electrode unit according to the first embodiment as viewed from the distal end side along the longitudinal axis.

[0038] Fig.31 It is a diagram showing a schematic configuration of an endoscope system according to a second embodiment.

[0039] Fig.32 It is a diagram showing a schematic configuration of an endoscope system according to a third embodiment. DETAILED DESCRIPTION

[0040] The preferred embodiment of the present invention is described below with reference to the accompanying drawings. In addition, in the drawings used in the following description, in order to make each component have a size that can be recognized on the drawings, the scale is different for each component, and the present invention is not limited to the number of components recorded in these drawings, the shape of the components, the ratio of the size of the components, and the relative positional relationship of the components.

[0041] (First Embodiment)

[0042] Figure 1 1 is a diagram showing a schematic configuration of an endoscope system 1 according to the first embodiment. The endoscope system 1 is a device that cuts or coagulates tissue in a subject under observation with an endoscope.

[0043] The endoscope system 1 of the present embodiment includes a resection scope 10 as an endoscope, an electrode unit 30, and an external device 50. In the present embodiment, as an example, the subject is a human body. In addition, in the present embodiment, as an example, the endoscope is generally called a resection scope, but the endoscope may also be a flexible endoscope.

[0044] The resection scope 10 includes a sheath 11 , a slider 20 and a telescope 21 .

[0045] The sheath 11 has a tubular portion along a linear longitudinal axis L. The sheath 11 is a portion that is inserted from outside the subject to inside the subject when the resection scope 10 is used. Both ends of the sheath 11 along the longitudinal axis L are open. When the resection scope 10 is used, the telescope 21 and the electrode unit 30 described later are inserted into the sheath 11.

[0046] An outer sheath for introducing a perfusion solution into the subject is disposed on the outer periphery of the sheath 11. The structure of the outer sheath and the like for introducing a perfusion solution into the subject is well known, so the description thereof is omitted. In the present embodiment, the perfusion solution is an electrolyte solution such as physiological saline and has conductivity.

[0047] The end inserted into the subject of the sheath 11 along the longitudinal axis L is called the distal end 11a, and the end opposite to the distal end 11a is called the proximal end 11b. The proximal end 11b of the sheath 11 is exposed outside the subject when the resectoscope 10 is used.

[0048] For the purpose of explanation, a pair of axes, namely, a first axis X and a second axis Y, which are orthogonal to the longitudinal axis L and orthogonal to each other, are defined below. In addition, one of the directions along the first axis X is set as the right direction, and the other is set as the left direction. In the direction along the second axis Y, one of the directions is set as the upper direction, and the other is set as the lower direction. In the present embodiment, as an example, the horizontal direction in the image captured by the telescope 21 is substantially parallel to the first axis X, and the vertical direction is substantially parallel to the second axis Y. In addition, the upper direction and the right direction are the upper and right directions in the image captured by the telescope 21.

[0049] A recovery electrode 11c made of a conductive material is exposed on the surface near at least the front end 11a of the sheath 11. Alternatively, the sheath 11 may be entirely made of a conductive material such as metal, and the entire surface of the sheath 11 may serve as the recovery electrode 11c.

[0050] A sheath connector 11d is provided near the base end 11b of the sheath 11. The sheath connector 11d is electrically connected to the recovery electrode 11c. A cable 56 is connected to the sheath connector 11d. The cable 56 electrically connects the sheath connector 11d to the high-frequency power supply control device 55 of the external device 50.

[0051] The slider 20 is arranged on the base end 11b side of the sheath 11. The slider 20 moves relative to the sheath 11 in the direction along the longitudinal axis L. The slider 20 is provided with a handle 20a. When a user applies force to the handle 20a with a finger, the slider 20 moves relative to the sheath 11 in the direction along the longitudinal axis L. In addition, since the mechanism for guiding the slider 20 so that it can move relative to the sheath 11 is the same as that of the existing resection scope 10, the illustration and description are omitted.

[0052] The slider 20 includes a scope holding portion 22 , an electrode unit holding portion 23 , and an electrode connector 24 . The scope holding portion 22 holds the telescope 21 .

[0053] The telescope 21 is used for optically observing the inside of the subject. The telescope 21 includes an elongated insertion portion 21 a, an eyepiece portion 21 b, and a light source connection portion 21 c. The insertion portion 21 a is inserted into the sheath 11 in a state where the telescope 21 is fixed to the scope holder 22 .

[0054] An observation window and an illumination light exit window are provided at the distal end portion 21a1 of the insertion portion 21a, and an eyepiece portion 21b and a light source connection portion 21c are provided at the proximal end portion 21a2 of the insertion portion 21a.

[0055] The eyepiece portion 21b is provided with an imaging unit 52. The imaging unit 52 is electrically connected to a video processor 51 of an external device 50. The video processor 51 is electrically connected to an image display device 53. In addition, one end of an optical fiber cable 54a is connected to the light source connection portion 21c. The other end of the optical fiber cable 54a is connected to a light source device 54 of the external device 50.

[0056] The visual field observed from the observation window provided at the front end portion 21a1 of the insertion portion 21a is captured by the imaging unit 52 and displayed on the image display device 53. In addition, the illumination light emitted from the light source device 54 is emitted from the illumination light emission window provided at the front end portion 21a1 of the insertion portion 21a. The structures of the telescope 21 and the external device 50 connected to the telescope 21 are the same as those of the existing resection scope 10, and therefore detailed description thereof is omitted.

[0057] The electrode unit holding part 23 holds an electrode unit 30 described later. The electrode connector 24 is electrically connected to the electrode unit 30 held by the electrode unit holding part 23. The electrode connector 24 is connected to a cable 56. The cable 56 electrically connects the electrode connector 24 to a high-frequency power supply control device 55 of an external device 50. In addition, the electrode connector 24 may be formed integrally with the sheath connector 11d.

[0058] The electrode unit 30 has a portion inserted into the sheath 11 when fixed to the electrode unit holding portion 23. The slider 20 moves relatively to the sheath 11 along the longitudinal axis L together with the telescope 21 and the electrode unit 30. A portion of the electrode unit 30 can protrude from the front end 11a of the sheath 11. As described later, an electrode 35 is provided at the portion of the electrode unit 30 protruding from the front end 11a of the sheath 11.

[0059] The electrode unit 30, the recovery electrode 11c and the high-frequency power supply control device 55 constitute a so-called bipolar electrosurgical device. The high-frequency power supply control device 55 includes a switch 55a. The switch 55a is, for example, a foot switch operated by the user with his foot. The high-frequency power supply control device 55 switches the output of the high-frequency current according to the operation of the switch 55a.

[0060] The high-frequency current outputted from the high-frequency power supply control device 55 flows in the subject between the electrode 35, the perfusion solution and the recovery electrode 11c. When the high-frequency power supply control device 55 outputs the high-frequency current, the subject's tissue in contact with the electrode 35 generates heat, and the tissue is removed or coagulated.

[0061] Figure 2 is a diagram showing the electrode unit 30 viewed from the left along the first axis X. Figure 2 In the figure, “up” refers to the upward direction. Figure 3 is a diagram of the electrode unit 30 viewed from below along the second axis Y. Figure 3In the figure, the upper direction is the left direction. Figure 4 This is a diagram of the electrode unit 30 as viewed from the distal end side along the longitudinal axis L. Figure 5 yes Figure 3 VV section view of. Figure 4 and Figure 5 In the figure, the up direction is the upper direction, and the right direction is the left direction. Figure 6 yes Figure 5 VI-VI section view. Figure 6 In the figure, the up direction is the right direction.

[0062] like Figure 2 and Figure 3 As shown, the electrode unit 30 has an elongated shape with the longitudinal direction being the direction along the longitudinal axis L. The electrode unit 30 includes a base end hard portion 31 , an electrode support portion 32 , and an electrode 35 .

[0063] The base end rigid part 31 is a part fixed to the electrode unit holding part 23 of the resection scope 10. The electrode support part 32 described later is coupled to the front end 31a of the base end rigid part 31. The electrical connection part 31c is provided at the base end 31b of the base end rigid part 31. The electrical connection part 31c is electrically connected to the electrode connector 24 of the resection scope 10 in a state where the base end rigid part 31 is fixed to the electrode unit holding part 23. In addition, the electrical connection part 31c is electrically connected to the electrode 35 via the conductive wire 33 inserted into the electrode unit 30.

[0064] The electrode support 32 supports the electrode 35. The electrode support 32 is a portion that protrudes from the front end 11a of the sheath 11 when the resection scope 10 is used. The electrode support 32 includes one or two front end hard portions 36 and one or two elastic regions 37. The electrode 35 is fixed to the front end hard portion 36.

[0065] The elastic region 37 connects the proximal end of the distal end rigid portion 36 and the distal end of the proximal end rigid portion 31. The bending rigidity of the elastic region 37 is lower than that of the distal end rigid portion 36 and the proximal end rigid portion 31.

[0066] The electrode 35 is made of a conductive linear member such as a metal wire, and protrudes from the surface of the distal end hard portion 36 .

[0067] The electrode 35 has a ring shape that protrudes from a point on the surface of the distal end rigid portion 36 toward the outside of the distal end rigid portion 36 and enters the inside of the distal end rigid portion 36 at a point different from the point. Specifically, the electrode 35 includes: a pair of base portions 35a supported by the distal end rigid portion 36 at two points on the surface of the distal end rigid portion 36 that are separated from each other; and a bridge portion 35b that connects the pair of base portions 35a in a state separated from the surface of the distal end rigid portion 36.

[0068] like Figure 4 and Figure 5 As shown, the bridge portion 35b is substantially U-shaped or U-shaped when viewed from the direction along the longitudinal axis L. When viewed from the direction along the first axis X, the top 35c of the bridge portion 35b protrudes from the base 35a in a direction intersecting the longitudinal axis L.

[0069] The pair of bases 35a are electrically connected to the wire 33 in the front end hard portion 36. Figure 5 and Figure 6 As shown, in this embodiment, as an example, the wire 33 and the electrode 35 are formed of the same metal linear member.

[0070] More specifically, the electrode support portion 32 of the present embodiment includes two distal end rigid portions 36. Each distal end rigid portion 36 has a columnar shape with the direction along the longitudinal axis L as the longitudinal direction. In the illustrated embodiment, the cross section of the distal end rigid portion 36 is substantially circular, but the cross section of the distal end rigid portion 36 may be a parallelogram or other polygonal shape.

[0071] The two tip rigid portions 36 are arranged at substantially the same position in the direction along the longitudinal axis L, and are arranged to be separated in the direction (left-right direction) along the first axis X. That is, the two tip rigid portions 36 are arranged so that there is an overlapping portion when viewed from the direction along the first axis X. Therefore, the two tip rigid portions 36 each have a surface that is opposed to each other in the direction along the first axis X, that is, an opposing surface 36a.

[0072] Here, "opposing surfaces" refer to the surface of the distal end rigid portion 36 disposed on the right side and facing substantially to the left, and the surface of the distal end rigid portion 36 disposed on the left side and facing substantially to the right. That is, the opposing surface 36a is a portion facing the space sandwiched by the two distal end rigid portions 36. Therefore, the opposing surfaces 36a of the two distal end rigid portions 36 do not necessarily have portions that are parallel to each other.

[0073] The pair of base portions 35a of the electrode 35 are respectively arranged at the two distal end rigid portions 36. That is, the electrode 35 is a metal wire 33 spanned between the two distal end rigid portions 36.

[0074] The pair of bases 35a are arranged so as to protrude from the opposing surfaces 36a of the two distal end hard portions 36 along the first axis X. In addition, the pair of bases 35a are arranged at substantially the same position in the direction along the longitudinal axis L. That is, the pair of bases 35a protrude from the pair of opposing surfaces 36a along the first axis X so as to approach each other.

[0075] The bridge portion 35b connects the front end portions of the pair of base portions 35a. The bridge portion 35b is curved in a convex shape from the pair of base portions 35a toward the bottom when viewed from the direction along the longitudinal axis L. Figure 4 and Figure 5 As shown, the top portion 35 c of the bridge portion 35 b is located below the lower end surfaces 36 b of the two distal end rigid portions 36 that face downward.

[0076] The electrode 35 having the structure described above, such as Figure 3 As shown in FIG. 1 , when viewed from the direction along the second axis Y, the electrode 35 is exposed to the outside only in the space S sandwiched between the two tip hard portions 36. In other words, the portion of the electrode 35 exposed to the outside is configured so as not to overlap with the two tip hard portions 36 when viewed from the direction along the second axis Y. Figure 4 As shown, when viewed from the distal end side along the longitudinal axis L, the electrode 35 is exposed to the outside only in the space S sandwiched by the two distal rigid portions 36. That is, the portion of the electrode 35 exposed to the outside is configured so as not to overlap with the distal end surfaces 36e of the two distal rigid portions 36.

[0077] like Figure 5 and Figure 6 As shown, each front end hard portion 36 is composed of a ceramic tube 32a and a covering portion 38. The ceramic tube 32a and the covering portion 38 have electrical insulation. The ceramic tube 32a is a hollow component in which the wire 33 is inserted. The covering portion 38 is a resin tube that covers the ceramic tube 32a. A through hole 32c for holding the base 35a of the electrode 35 is formed on the side of the ceramic tube 32a and the covering portion 38.

[0078] As an example, the electrode support part 32 of this embodiment has two elastic regions 37. The two elastic regions 37 are connected to the base ends of the two distal rigid parts 36. Alternatively, the electrode support part 32 may have one elastic region 37 connected to the base ends of both the two distal rigid parts 36.

[0079] The elastic region 37 of the present embodiment is composed of a coating 38, which is a resin tube. In the present embodiment, as an example, the coating 38 of the distal end hard portion 36 and the coating 38 of the elastic region 37 are the same member that is continuous in the direction along the longitudinal axis L. The wire 33 is inserted into the coating 38 of the elastic region 37. That is, in the present embodiment, the ceramic tube 32a inserted into the coating 38 has the effect of making the bending rigidity of the distal end hard portion 36 higher than that of the elastic region 37.

[0080] The base end rigid portion 31 of the present embodiment is composed of a coating portion 38 and a metal tube 31d, and the coating portion 38 is a resin tube. In the present embodiment, as an example, the coating portion 38 of the base end rigid portion 31 and the coating portion 38 of the elastic region 37 are the same member that is continuous in the direction along the longitudinal axis L. The wire 33 is inserted into the coating portion 38 of the base end rigid portion 31. The metal tube 31d is coated on the outer periphery of the coating portion 38. That is, in the present embodiment, the metal tube 31d has a function of making the bending rigidity of the base end rigid portion 31 higher than that of the elastic region 37.

[0081] In addition, the method of making the bending rigidity of the elastic region 37 lower than that of the distal end rigid portion 36 and the proximal end rigid portion 31 is not limited to the method of making the materials of the constituent members different as in the present embodiment. For example, by making the outer diameter of the elastic region 37 thinner than that of the distal end rigid portion 36 and the proximal end rigid portion 31, the bending rigidity of the elastic region 37 can also be made lower than that of the distal end rigid portion 36 and the proximal end rigid portion 31.

[0082] Reference Figure 7 , Figure 8 as well as Fig. 9 , a first method of resecting tissue in the organ 100 of a subject using the electrode unit 30 and the endoscope system 1 of the present embodiment will be described. Figure 7 , Figure 8 as well as Fig. 9 It is a diagram schematically showing the inside of the organ 100 .

[0083] When using the electrode unit 30 to remove tissue in the organ 100, the user first places the electrode support 32 in the organ 100 so that the lower end surface 36b of the distal hard portion 36 faces the tissue. Figure 7 As shown, the user brings the electrode support 32 into contact with the wall surface of the organ 100 in such a manner that the electrode 35 protruding from the lower end surface 36b of the distal end hard portion 36 contacts the tissue. The method of inserting the electrode unit 30 and the sheath 11 of the resection scope 10 into the organ 100 and the method of filling the organ 100 with the perfusion solution are the same as those of the conventional electrode unit, and thus the description thereof is omitted.

[0084] Next, the user operates the switch 55a to start outputting high-frequency current from the high-frequency power supply control device 55. As a result, the high-frequency current flows from the electrode 35 to the recovery electrode 11c through the perfusion solution, so that the tissue in contact with the electrode 35 is heated and the tissue is cut off. When the tissue is cut off due to the start of output of the high-frequency current, as shown in FIG. Figure 8 As shown, electrode 35 is inserted into the tissue.

[0085] Here, as described above, the electrode 35 is arranged so as not to overlap with the distal end hard portion 36 when viewed from the direction (below) along the second axis Y. Therefore, when the electrode 35 enters the tissue to a predetermined depth, the distal end hard portion 36 abuts against the tissue that is not cut by the electrode 35. That is, the lower end surface 36b of the distal end hard portion 36 functions as a stopper that limits the depth of entry of the electrode 35 into the tissue.

[0086] If the electrode 35 is configured to overlap the lower end surface 36b of the front end hard portion 36 when viewed from below, unlike the present embodiment, the lower end surface 36b is pressed against the cut tissue by the electrode 35. In this case, the force of the lower end surface 36b restricting the electrode 35 from advancing into the tissue may be weaker than that of the present embodiment. In the present embodiment, such a state can be avoided, and the depth of the electrode 35 entering the tissue can be reliably restricted.

[0087] Therefore, in this embodiment, even if the force with which the user pushes the electrode support part 32 against the wall surface of the organ 100 changes, it is possible to prevent the electrode 35 from further entering the tissue from the state where the distal hard portion 36 is in contact with the tissue.

[0088] Then, if Fig. 9 As shown, the user moves the resection scope 10 to move the electrode support 32 along the wall surface of the organ 100. Then, the electrode 35 moves in the tissue along the wall surface, so that a tissue piece of a predetermined thickness is resected.

[0089] Here, as described above, even if the force with which the user presses the electrode support 32 against the wall of the organ 100 changes, the depth of the electrode 35 entering the tissue remains constant. In addition, even if the force with which the user presses the resectoscope 10 in the direction of the tissue changes, the change in the force with which the electrode 35 presses in the direction of the tissue is kept substantially constant by the bending of the elastic region 37. Thus, the amount of deformation of the tissue by the front end hard portion 36 is kept substantially constant, and the depth of the electrode 35 entering the tissue is also kept substantially constant. In addition, in this embodiment, even if the user does not move the resectoscope 10 along the shape of the wall of the organ 100 and the distance between the wall of the organ 100 and the front end 11a of the sheath 11 changes, the front end hard portion 36 is kept in contact with the tissue due to the elastic deformation of the elastic region 37. And, if the front end hard portion 36 is in contact with the tissue, the depth of the electrode 35 entering the tissue remains constant as described above.

[0090] Next, refer to Fig.10 , Fig.11 as well as Fig.12 , a second method of resecting tissue in the organ 100 of the subject using the electrode unit 30 and the endoscope system 1 of the present embodiment will be described.

[0091] In the second method, Fig.10 As shown, the user makes the electrode support part 32 in the organ 100 so that the front end surface 36e of the front end hard part 36 faces the predetermined tissue to be removed. At this moment, the electrode unit 30 is not in contact with the predetermined tissue to be removed and its vicinity. Next, the user operates the switch 55a to start outputting the high-frequency current from the high-frequency power supply control device 55 while the electrode unit 30 is not in contact with the predetermined tissue to be removed and its vicinity.

[0092] Then, if Fig.11 As shown in FIG. 1 , the user moves the electrode unit 30 in the distal direction so that the distal end surface 36e of the distal end hard portion 36 abuts against the wall surface of the organ 100. As described above, when viewed from the direction along the longitudinal axis L, the electrode 35 is arranged at a position that does not overlap with the distal end surface 36e. Therefore, in this operation, the distal end surface 36e abuts against the wall surface of the organ 100, thereby stopping the movement of the electrode unit 30 in the distal direction. That is, the distal end surface 36e of the distal end hard portion 36 functions as a stopper that limits the depth of the electrode 35 entering the tissue.

[0093] In addition, Fig.11 In the stage shown, when the electrode 35 contacts the tissue, the tissue contacted by the electrode 35 and the tissue contacted by the front end surface 36e are located at different positions. Fig.11 In the stage shown, even when the tissue is cut by the electrode 35 , the distal end hard portion 36 abuts against the tissue that is not cut by the electrode, so the distal end surface 36 e of the distal end hard portion 36 functions as a stopper.

[0094] Then, if Fig.12 As shown in FIG. 1 , the user moves the electrode support 32 downward while bringing the distal end surface 36e into contact with the wall surface of the organ 100, thereby bringing the lower end surface 36b of the distal hard portion 36 into contact with the tissue. By this operation, the elastic region 37 bends. Fig.12 In the stage shown, similarly to the first method, the lower end surface 36b of the distal end hard portion 36 functions as a stopper that limits the depth of the electrode 35 entering the tissue. Therefore, even when the second method is used, similarly to the first method, the depth of the electrode 35 entering the tissue can be kept constant.

[0095] Then, if Fig. 9 As shown, the user moves the resection scope 10 in the same manner as the first method to move the electrode support 32 along the wall surface of the organ 100. Then, the annular electrode 35 moves in the direction along the wall surface in the tissue, so that a tissue piece of a predetermined thickness is resected.

[0096] As described above, the electrode unit 30 and the endoscope system 1 of the present embodiment can maintain a constant depth of the electrode 35 inserted into the tissue even when there is a shake on the trajectory of the electrode 35 moved by the user or when there is a change in the force applied by the user to the electrode 35. Therefore, according to the electrode unit 30 and the endoscope system 1 of the present embodiment, it is easy to control the thickness of the tissue to be removed.

[0097] In addition, the structures of the electrode support part 32 and the electrode 35 included in the electrode unit 30 are not limited to those of the present embodiment.

[0098] Fig.13 , Fig.14 and Fig.15 FIG. 1 shows a first modification of the electrode unit 30. When the electrode unit 30 according to the first modification is viewed from the direction along the first axis X, the lower end surface 36b of the distal end hard portion 36 has a curved shape.

[0099] The lower end surface 36b of the distal end rigid portion 36 of the first modified example has a curved surface portion 36b1 that curves upward toward the distal end side when viewed from the direction along the first axis X. In addition, the electrode 35 protrudes in a direction substantially orthogonal to the curved surface portion 36b1 when viewed from the direction along the first axis X. Specifically, the electrode 35 protrudes from the distal end rigid portion 36 downward and toward the distal end.

[0100] The electrode unit 30 of the first modified example facilitates the operation of bringing the electrode 35 into contact with tissue when the wall surface of the organ 100 is substantially perpendicular to the longitudinal axis L.

[0101] Fig.16 , Fig.17 and Fig.18 A second modification of the electrode unit 30 is shown. In the electrode unit 30 of the second modification, the top 35c of the electrode 35 protrudes downward from the lower end surface 36b of the distal end rigid portion 36 and protrudes distally from the distal end surface 36e of the distal end rigid portion 36.

[0102] The electrode unit 30 according to the first modification example can make the electrode 35 contact with tissue and excise the tissue by pressing either the lower end surface 36 b or the front end surface 36 e against the wall surface of the organ 100 .

[0103] In addition, the front end rigid portion 36 of the second modified example includes a convex portion 36f. The convex portion 36f protrudes in a direction different from that of the electrode 35. Specifically, the convex portion 36f protrudes upward along the second axis Y from the front end of the front end rigid portion 36. The surface on the front end side of the convex portion 36f is the same surface as the front end surface 36e. By forming the convex portion 36f at the front end of the front end rigid portion 36, the area in contact with the wall surface of the organ 100 becomes larger, so even if the pressing force for bringing the electrode 35 into contact with the tissue is large, the pressure on the tissue is dispersed and changes less. As a result, the amount of deformation of the tissue by the front end rigid portion 36 is kept approximately constant, and it is easy to keep the depth of the electrode 35 inserted into the tissue constant.

[0104] Fig.19 , Fig. 20 and Fig.21 The third modification of the electrode unit 30 is shown. In the electrode unit 30 of the third modification, similarly to the second modification, the top 35c of the electrode 35 protrudes downward from the lower end surface 36b of the distal rigid portion 36 and protrudes distally from the distal end surface 36e of the distal rigid portion 36.

[0105] Furthermore, the front end rigid portion 36 of the third modified example includes a pair of convex portions 36f protruding from the front end in the left-right direction along the first axis X. In the third modified example shown in the figure, the pair of convex portions 36f protrude from the pair of front end rigid portions 36 in directions away from each other along the first axis X. Alternatively, the pair of convex portions 36f may protrude from the pair of front end rigid portions 36 in directions approaching each other along the first axis X.

[0106] The electrode unit 30 of the third modification example is similar to the second modification example, and can make the electrode 35 contact with the tissue and remove the tissue by pressing either the lower end surface 36b or the front end surface 36e against the wall surface of the organ 100. In addition, by forming the convex portion 36f at the front end of the front end hard portion 36, the area in contact with the wall surface of the organ 100 becomes larger, so it is easy to keep the depth of the electrode 35 inserted into the tissue constant.

[0107] Fig. 22 , Fig.23 and Fig.24 4 shows a fourth modification of the electrode unit 30. The electrode support portion 32 of the fourth modification includes a distal rigid portion 36 and two elastic regions 37. In addition, the top portion 35c of the electrode 35 protrudes downward from the lower end surface 36b of the distal rigid portion 36 and protrudes toward the distal end side from the distal end surface 36e of the distal rigid portion 36.

[0108] Fig.25 , Fig.26 and Fig. 274 shows a fifth modification of the electrode unit 30. The electrode support portion 32 of the fifth modification includes a distal rigid portion 36 and an elastic region 37. In addition, the top portion 35c of the electrode 35 protrudes downward from the lower end surface 36b of the distal rigid portion 36 and protrudes toward the distal end side from the distal end surface 36e of the distal rigid portion 36.

[0109] As shown in the fourth and fifth modified examples, the number of the distal end hard portion 36 and the elastic region 37 included in the electrode support portion 32 may be one or two.

[0110] Fig.28 , Fig.29 and Fig.30 6 shows a sixth modification of the electrode unit 30. The electrode support portion 32 of the sixth modification includes a distal rigid portion 36 and an elastic region 37. In addition, the top portion 35c of the electrode 35 protrudes downward from the lower end surface 36b of the distal rigid portion 36. Unlike the fifth modification, the top portion 35c of the electrode 35 is located closer to the base end side than the distal end surface 36e of the distal rigid portion 36.

[0111] (Second Embodiment)

[0112] Hereinafter, a second embodiment of the present invention will be described. Hereinafter, only the differences from the first embodiment will be described, and the same components as those of the first embodiment are denoted by the same reference numerals, and their description will be appropriately omitted.

[0113] Fig.31 1 is a diagram showing a schematic configuration of an endoscope system 1 according to a second embodiment. The endoscope system 1 according to the present embodiment can move the electrode unit 30 along the longitudinal axis L relative to the telescope 21 .

[0114] Specifically, in the endoscope system 1 of the present embodiment, the slider 20 is separated from the electrode unit holding portion 23 . The electrode unit holding portion 23 and the slider 20 independently move relatively to the sheath 11 along the longitudinal axis L. The electrode connector 24 is provided on the electrode unit holding portion 23 .

[0115] In the endoscope system 1 of this embodiment, by moving the electrode unit holding portion 23 relative to the sheath 11 along the longitudinal axis L, only the electrode unit 30 can be moved relative to the sheath 11 along the longitudinal axis L while the position of the telescope 21 relative to the sheath 11 is fixed.

[0116] Furthermore, in the endoscope system 1, the length of the elastic region 37 protruding from the front end 11a of the sheath 11 can be changed by relatively moving the electrode unit 30 relative to the sheath 11 along the longitudinal axis L. The portion of the elastic region 37 located closer to the proximal end than the front end 11a of the sheath 11 is surrounded by the sheath 11, so that it is difficult to cause bending deformation. Therefore, in the endoscope system 1 of this embodiment, by changing the protruding length of the elastic region 37 protruding from the front end 11a of the sheath 11, the length of the elastic deformation of the elastic region 37 can be changed when the front end hard portion 36 is pressed against the wall surface of the organ 100.

[0117] When the distal end rigid portion 36 is pressed against the wall surface of the organ 100 to elastically deform the elastic region 37, the distal end rigid portion 36 and the electrode 35 move upward within the field of view of the telescope 21. At this time, there is a case where the distal end rigid portion 36 and the electrode 35 move outside the field of view of the telescope 21. In this case, in the present embodiment, the distal end rigid portion 36 and the electrode 35 are prevented from moving outside the field of view of the telescope 21 by moving the electrode unit 30 toward the proximal end relative to the sheath 11 to shorten the length of elastic deformation of the elastic region 37.

[0118] In addition, the structure of the electrode support portion 32 of the electrode unit 30 of this embodiment can be Figures 2 to 30 Any of the first embodiment and its modified examples shown.

[0119] (Third Embodiment)

[0120] Hereinafter, a third embodiment of the present invention will be described. Hereinafter, only the differences from the first embodiment will be described, and the same components as those of the first embodiment are denoted by the same reference numerals, and their description will be appropriately omitted.

[0121] Fig.32 1 is a diagram showing a schematic configuration of an endoscope system 1 according to a third embodiment. The endoscope system 1 according to the present embodiment is different from the first embodiment in that an electrode unit 30 includes an electrode sheath 45 and an operation section 46 .

[0122] The electrode sheath 45 is a tubular member having a higher bending rigidity than the elastic region 37. The electrode sheath 45 is disposed so as to surround the outer periphery of the proximal end rigid portion 31. The electrode sheath 45 is relatively movable along the longitudinal axis L with respect to the proximal end rigid portion 31.

[0123] When the electrode sheath 45 is moved to the most distal side of the movable range relative to the base end rigid portion 31, the front end 45a of the electrode sheath 45 is located at the front end side of the front end 31a of the base end rigid portion 31. Furthermore, when the electrode sheath 45 is moved to the most distal side of the movable range relative to the base end rigid portion 31, part or all of the elastic region 37 is accommodated in the electrode sheath 45.

[0124] The base end 45b of the electrode sheath 45 protrudes further toward the base end side than the base end 11b of the sheath 11. An operation part 46 is provided at a portion of the electrode sheath 45 that protrudes further toward the base end side than the base end 11b of the sheath 11. When the front end 11a of the sheath 11 and the electrode support part 32 of the electrode unit 30 are inserted into the subject, the operation part 46 is located outside the subject.

[0125] The operation part 46 can move relatively with respect to the base end hard part 31 together with the electrode sheath 45. That is, by moving the operation part 46 relatively with respect to the base end hard part 31, the sheath 11 moves relatively with respect to the base end hard part 31. Moreover, in the electrode unit 30 of the present embodiment, when the sheath 11 moves relatively with respect to the base end hard part 31, the protruding length of the elastic region 37 protruding from the front end 45a of the electrode sheath 45 can be changed. The portion of the elastic region 37 surrounded by the electrode sheath 45 is not easily bent and deformed. Therefore, the electrode unit 30 of the present embodiment can change the length of elastic deformation of the elastic region 37 when the front end hard part 36 is pushed against the wall surface of the organ 100 by changing the protruding length of the elastic region 37 protruding from the front end 45a of the electrode sheath 45.

[0126] When the endoscope system 1 is used, if the distal end rigid portion 36 is pushed against the wall surface of the organ 100 and the elastic region 37 is elastically deformed, the distal end rigid portion 36 and the electrode 35 move upward within the field of view of the telescope 21. At this time, there is a case where the distal end rigid portion 36 and the electrode 35 move outside the field of view of the telescope 21. In this case, in the present embodiment, by moving the electrode sheath 45 toward the distal end relative to the proximal rigid portion 31, the length of the elastic deformation of the elastic region 37 is shortened, and the distal end rigid portion 36 and the electrode 35 can be prevented from moving outside the field of view of the telescope 21.

[0127] In addition, the structure of the electrode support portion 32 of the electrode unit 30 of this embodiment can be Figures 2 to 30 Any structure in the first embodiment and its modified examples shown.

[0128] The present invention is not limited to the above-described embodiments, and can be appropriately modified within the scope not departing from the gist or concept of the invention as read from the claims and the entire specification. The electrode unit and endoscope system accompanying such modifications are also included in the technical scope of the present invention.

Claims

1. An electrode unit that uses high-frequency current to cut or coagulate tissue in a subject, characterized in that: The electrode unit comprises an electrode support and an electrode. The electrode support portion comprises: a pair of front end hard portions, the surfaces of which are covered with an electrically insulating material; and an elastic region portion provided on the base end side of each of the pair of distal end rigid portions and having a bending rigidity lower than that of the pair of distal end rigid portions, The electrode comprises: a pair of base portions, each supported by the pair of front end rigid portions, the pair of base portions being disposed on mutually opposing surfaces of the pair of front end rigid portions; and a mounting portion connecting the pair of base portions, wherein the mounting portion is convex downward from the pair of base portions when viewed in a direction along the longitudinal axis, The electrode is arranged so as not to overlap with the distal end hard portion when viewed from the lower side.

2. The electrode unit according to claim 1, characterized in that The electrode unit further comprises: a base end hard portion connected to the base end of the electrode support portion; and An electrical connection portion provided at the base end hard portion and electrically connected to the electrode, The bridge portion connects the pair of base portions while protruding downwardly from the pair of distal end hard portions.

3. The electrode unit according to claim 2, characterized in that The pair of base portions protrude from between the front ends and base ends of the pair of front end hard portions.

4. The electrode unit according to claim 2, characterized in that: The pair of distal end hard portions include a convex portion that protrudes in a direction different from a protruding direction of the base portion.

5. The electrode unit according to claim 1, characterized in that: When a pair of axes that are orthogonal to the length axis and to each other are determined as the first axis and the second axis, one of the directions along the first axis is set as the right direction, the other of the directions along the first axis is set as the left direction, one of the directions along the second axis is set as the upper direction, and the other of the directions along the second axis is set as the lower direction, the mounting portion is convex in shape from the pair of bases toward the bottom.

6. The electrode unit according to claim 5, characterized in that When the pair of distal end rigid portions are viewed from a direction opposite to a direction in which the electrodes protrude, the pair of base portions of the electrodes protrude so as to approach each other at opposing surfaces of the pair of distal end rigid portions.

7. The electrode unit according to claim 2, characterized in that: The electrode unit comprises: a tubular electrode sheath surrounding the outer circumference of the base end hard portion; and An operating unit moves the electrode sheath to a position surrounding an outer periphery of the elastic region.

8. An endoscope system, characterized in that: The endoscope system comprises the electrode unit according to claim 1.

9. The endoscope system according to claim 8, characterized in that: The endoscope system includes: A sheath for the electrode unit to penetrate; A telescope inserted into the sheath; a slider, which is on the base end side of the sheath and holds the telescope so as to be freely movable in a direction along the longitudinal axis of the sheath, An electrode unit holding portion is provided on the proximal end side of the sheath and holds the electrode unit so as to be movable in a direction along the longitudinal axis of the sheath independently of the telescope.

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