阅读说明：本技术 电极单元及内窥镜系统 (Electrode unit and endoscope system ) 是由 生熊聪一 酒井悠次 林田刚史 塚越贵之 于 2018-12-27 设计创作，主要内容包括：电极单元包括：电极支承部,其向被检体内插入；基端硬质部,其与所述电极支承部的基端连结；前端硬质部,其设置于所述电极支承部的前端部；弹性区域,其设置于所述电极支承部,将所述前端硬质部及所述基端硬质部连接,所述弹性区域的弯曲刚性比所述前端硬质部及所述基端硬质部低；电极,其由所述前端硬质部支承,从所述前端硬质部的外表面突出；电连接部,其设置于所述基端硬质部,与所述电极电连接；以及操作部,其设置于所述基端硬质部,通过相对于所述基端硬质部相对地移动,使所述电极相对于所述前端硬质部相对地移动。(The electrode unit includes: an electrode support portion inserted into the subject; a base end hard portion connected to a base end of the electrode support portion; a distal end hard portion provided at a distal end portion of the electrode support portion; an elastic region provided in the electrode support portion and connecting the distal end hard portion and the base end hard portion, the elastic region having lower bending rigidity than the distal end hard portion and the base end hard portion; an electrode supported by the distal end hard portion and protruding from an outer surface of the distal end hard portion; an electrical connection portion provided in the base end hard portion and electrically connected to the electrode; and an operation section provided on the base end hard section and moving the electrode relative to the distal end hard section by moving the operation section relative to the base end hard section.)

1. An electrode unit for cutting or coagulating a tissue in a subject under observation by an endoscope using a high-frequency current,

the electrode unit includes:

an electrode support portion inserted into the subject;

a base end hard portion connected to a base end of the electrode support portion;

a distal end hard portion provided at a distal end portion of the electrode support portion;

an elastic region provided in the electrode support portion and connecting the distal end hard portion and the base end hard portion, the elastic region having lower bending rigidity than the distal end hard portion and the base end hard portion;

an electrode supported by the distal end hard portion and protruding from an outer surface of the distal end hard portion;

an electrical connection portion provided in the base end hard portion and electrically connected to the electrode; and

and an operation section provided on the base end hard section and moving the electrode relative to the distal end hard section by moving the operation section relative to the base end hard section.

2. The electrode-unit of claim 1,

the electrode is disposed so as to be capable of moving forward and backward in a protruding direction of the electrode with respect to the distal end hard portion,

the distal end hard portion includes a regulating portion that is moved relative to the distal end hard portion in accordance with movement of the operation portion, thereby changing a movable range in which the electrode moves in the protruding direction.

3. The electrode-unit of claim 1,

the direction in which the electrode protrudes from the distal end hard portion is a direction intersecting a longitudinal axis from the base end toward the distal end,

the operation portion transmits a force to the electrode to move the electrode in a direction along the longitudinal axis with respect to the distal end hard portion,

the distal end hard portion includes a conversion portion that converts a direction of force transmitted from the operation portion to the electrode and moves the electrode in a direction intersecting both a protruding direction of the electrode and the longitudinal axis.

4. An endoscope unit characterized in that,

the endoscope unit includes the electrode unit of claim 1.

Technical Field

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

Background

An electric scalpel is known as a technique for cutting or coagulating a tissue of a subject such as a human body. For example, japanese patent application laid-open No. 2002-95677 discloses an resectoscope system that uses a high-frequency current to resect or coagulate a tissue in a subject under observation by an endoscope. In the technique disclosed in japanese patent laid-open publication No. 2002-95677, a high-frequency current is caused to flow to an electrode formed in a ring shape, whereby tissue is excised or coagulated.

Such an electrode formed in a ring shape as disclosed in japanese patent laid-open publication No. 2002-95677 is used, for example, for cutting a tissue in an organ such as a bladder. Here, the depth of the electrode into the wall surface of the organ varies depending on the intensity of the force with which the user presses the electrode against the wall surface. Therefore, when a tissue is excised using a conventional electrode formed in a ring shape, variations occur in the thickness of the excised tissue depending on the degree of force applied by the user. For example, when the excised tissue is used for biopsy, a tissue having a predetermined thickness is required, and therefore, the thickness of the excised tissue is preferably fixed regardless of the user.

The present invention has been made to solve the above-described problems, and an object thereof is to provide an electrode unit and an endoscope system that can easily control the thickness of a tissue to be excised.

Disclosure of Invention

Means for solving the problems

An electrode unit according to an aspect of the present invention is an electrode unit for cutting or coagulating a tissue in a subject using a high-frequency current under observation by an endoscope, including: an electrode support portion inserted into the subject; a base end hard portion connected to a base end of the electrode support portion; a distal end hard portion provided at a distal end portion of the electrode support portion; an elastic region provided in the electrode support portion and connecting the distal end hard portion and the base end hard portion, the elastic region having lower bending rigidity than the distal end hard portion and the base end hard portion; an electrode supported by the distal end hard portion and protruding from an outer surface of the distal end hard portion; an electrical connection portion provided in the base end hard portion and electrically connected to the electrode; and an operation section provided on the base end hard section and moving the electrode relative to the distal end hard section by moving the operation section relative to the base end hard section. Further, an endoscope system according to an aspect of the present invention includes the electrode unit.

Drawings

Fig. 1 is a diagram showing a schematic configuration of an endoscope system according to embodiment 1.

Fig. 2 is a view of the electrode unit of embodiment 1 as viewed along the 1 st axis.

Fig. 3 is a view of the electrode unit of embodiment 1 as viewed along the 2 nd axis.

Fig. 4 is a sectional view IV-IV of fig. 3.

Fig. 5 is a V-V sectional view of fig. 4.

Fig. 6 is a diagram illustrating an operation of the restricting unit according to embodiment 1.

Fig. 7 is a diagram illustrating an operation of the restricting unit according to embodiment 1.

Fig. 8 is a diagram showing a case where tissue is excised using the electrode unit of embodiment 1.

Fig. 9 is a diagram showing a case where tissue is excised using the electrode unit of embodiment 1.

Fig. 10 is a diagram showing a case where tissue is excised using the electrode unit of embodiment 1.

Fig. 11 is a diagram showing the structure of the electrode unit of embodiment 2.

Fig. 12 is a diagram showing the structure of the electrode unit of embodiment 2.

Fig. 13 is a diagram showing the structure of the electrode unit of embodiment 3.

Detailed Description

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. In the drawings used in the following description, the dimensions are set to such an extent that the respective components can be recognized in the drawings, and therefore, the scale is different for each component, and the present invention is not limited to the number of components, the shapes of components, the ratio of the sizes of components, and the relative positional relationship of the components described in the drawings.

(embodiment 1)

Fig. 1 is a diagram showing a schematic configuration of an endoscope system 1. The endoscope system 1 is a device that cuts or coagulates a tissue under observation by an endoscope in a subject.

The endoscope system 1 of the present embodiment includes a resectoscope 10 as an endoscope, an electrode unit 30, and an external device 50. In the present embodiment, the subject is a human body, for example. In the present embodiment, as an example, a so-called resectoscope is generally used as an endoscope, but the endoscope may be a flexible endoscope.

The resectoscope 10 includes a sheath 11, a slider 20, and a telescope 21.

The sheath 11 has a tubular portion along the linear length axis L. The sheath 11 is a portion to be inserted from outside the subject into the subject when the resectoscope 10 is used. Both ends of the sheath 11 in the direction of the longitudinal axis L are open. When the resectoscope 10 is used, a telescope 21 and an electrode unit 30, which will be described later, are inserted into the sheath 11.

An outer sheath for introducing the perfusion fluid into the subject is disposed on the outer periphery of the sheath 11. The configuration for introducing the perfusion fluid into the subject, such as the outer sheath, is well known, and therefore, the description thereof is omitted. In the present embodiment, the perfusate is an electrolyte solution such as physiological saline, for example, and has conductivity.

Of both ends of the sheath 11 in the direction along the longitudinal axis L, an end portion on the side inserted into the subject is referred to as a distal end 11a, and an end portion on the opposite side from the distal end 11a is referred to as a proximal end 11 b. The proximal end 11b of the sheath 11 is exposed to the outside of the subject when the resectoscope 10 is used.

Hereinafter, for the sake of explanation, a pair of axes orthogonal to the length axis L and to each other, i.e., the 1 st axis X and the 2 nd axis Y, is defined. One of the directions along the 1 st axis X is defined as a right direction, and the other is defined as a left direction. One of the directions along the 2 nd axis Y is an upward direction, and the other is a downward direction. In the present embodiment, for example, the horizontal direction of the image captured by the telescope 21 is substantially parallel to the 1 st axis X, and the vertical direction is substantially parallel to the 2 nd axis Y. The up and right directions are up and right in the image captured using the telescope 21.

The recovery electrode 11c made of a conductive material is exposed on the surface of the sheath 11 at least in the vicinity of the distal end 11 a. The entire sheath 11 may be made of a conductive material such as metal, and the entire surface of the sheath 11 may be the recovery electrode 11 c.

Further, 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 11 c. The sheath connector 11d is connected to a cable 56. The cable 56 electrically connects the sheath connector 11d and the high-frequency power supply control device 55 of the external device 50.

The slider 20 is disposed on the base end 11b side of the sheath 11. The slider 20 relatively moves with respect to the sheath 11 in a direction along the length axis L. The slider 20 is provided with a handle 20 a. The user applies a force to the handle 20a by hand, whereby the slider 20 is relatively moved in a direction along the length axis L with respect to the sheath 11. The mechanism for guiding the slider 20 so as to be movable relative to the sheath 11 is the same as the conventional resectoscope 10, and therefore, illustration and description thereof are omitted.

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

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

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

The eyepiece portion 21b is equipped with an imaging unit 52. The imaging unit 52 is electrically connected to the video processor 51 of the external apparatus 50. An image display device 53 is electrically connected to the video processor 51. One end of the optical fiber cable 54a is connected to the light source connection portion 21 c. The other end of the optical fiber cable 54a is connected to the light source device 54 of the external device 50.

The field of view observed through the observation window provided in the distal end portion 21a1 of the insertion portion 21a is captured by the imaging unit 52 and displayed on the image display device 53. The illumination light emitted from the light source device 54 is emitted from an illumination light exit window provided at the distal end portion 21a1 of the insertion portion 21 a. The telescope 21 and the external device 50 connected to the telescope 21 have the same configuration as the conventional resectoscope 10, and therefore, detailed description thereof is omitted.

The electrode unit holding portion 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 portion 23. A cable 56 is connected to the electrode connector 24. The cable 56 electrically connects the electrode connector 24 with the high-frequency power supply control device 55 of the external device 50.

The electrode unit 30 has a portion inserted into the sheath 11 while being fixed to the electrode unit holding portion 23. The slider 20 moves along the longitudinal axis L relative to the sheath 11 together with the telescope 21 and the electrode unit 30. A part of the electrode unit 30 can protrude from the front end 11a of the sheath 11. As described later, the electrode 35 is disposed at a portion of the electrode unit 30 protruding from the distal end 11a of the sheath 11.

The electrode unit 30, the collecting electrode 11c, and the high-frequency power supply control device 55 constitute a so-called bipolar type electro-surgical apparatus. The high-frequency power supply control device 55 includes a switch 55 a. The switch 55a is, for example, a foot switch operated by the user's foot. The high-frequency power supply control device 55 switches the presence/absence of the output of the high-frequency current in accordance with the operation of the switch 55 a.

The high-frequency current output from the high-frequency power supply control device 55 flows between the electrode 35, the perfusate, and the collecting electrode 11c in the subject. In a state where the high-frequency power supply control device 55 outputs the high-frequency current, the tissue of the subject in contact with the electrode 35 generates heat, and the tissue is excised or coagulated.

Fig. 2 is a view of the electrode unit 30 viewed from the left along the 1 st axis X. In fig. 2, the upper side in the drawing is the upper direction. Fig. 3 is a view of the electrode unit 30 viewed from below along the 2 nd axis Y. In fig. 3, the upper direction in the drawing is the left direction. Fig. 4 is a sectional view IV-IV of fig. 3. In fig. 4, the upper direction in the drawing is the upper direction, and the right direction in the drawing is the left direction. Fig. 5 is a V-V sectional view of fig. 4. In fig. 5, the upper direction in the drawing is the upper direction.

As shown in fig. 2 and 3, the electrode unit 30 has an elongated shape having a longitudinal direction along the longitudinal axis L. The electrode unit 30 includes a proximal end hard portion 31, an electrode support portion 32, an electrode 35, and an operation portion 40.

The proximal end hard portion 31 is a portion fixed to the electrode unit holding portion 23 of the resectoscope 10. An electrode support portion 32 described later is coupled to the distal end 31a of the proximal end hard portion 31. An electrical connection portion 31c is provided at the base end 31b of the base end hard portion 31. The electrical connection portion 31c is electrically connected to the electrode connector 24 of the resectoscope 10 in a state where the base end hard portion 31 is fixed to the electrode unit holding portion 23. The electrical connection portion 31c is electrically connected to the electrode 35 via a conductive wire 33 inserted through the electrode unit 30.

The electrode support portion 32 supports the electrode 35. The electrode support portion 32 is a portion protruding from the distal end 11a of the sheath 11 when the resectoscope 10 is used. The electrode support portion 32 includes 1 or 2 distal end hard portions 36 and 1 or 2 elastic regions 37.

The elastic region 37 connects the base end of the distal end hard portion 36 and the distal end of the base end hard portion 31. The elastic region 37 has lower bending rigidity than the distal end hard portion 36 and the base end hard portion 31.

The electrode 35 is formed of a linear member having conductivity such as a metal wire. The electrode 35 protrudes from the surface of the distal end hard portion 36.

The electrode 35 has a ring shape protruding from one point of the surface of the distal end hard portion 36 to the outside of the distal end hard portion 36 and entering the inside of the distal end hard portion 36 at a different point. Specifically, the electrode 35 includes a pair of base portions 35a supported by the distal end hard portion 36 at 2 points spaced apart from each other on the surface of the distal end hard portion 36, and a bridge portion 35b connecting the pair of base portions 35a in a state spaced apart from the surface of the distal end hard portion 36.

As shown in fig. 4, the bridge portion 35b has a substantially コ shape or a substantially U shape when viewed from the direction along the longitudinal axis L. The top portion 35c of the bridge portion 35b protrudes from the base portion 35a in a direction intersecting the longitudinal axis L when viewed from the direction along the 1 st axis X.

The pair of base portions 35a are electrically connected to the electric wire 33 in the distal end hard portion 36. As shown in fig. 4 and 5, in the present embodiment, the wire 33 and the electrode 35 are formed of the same metal wire member as an example.

The operation portion 40 is disposed in the base end hard portion 31. The operation portion 40 is located closer to the proximal end side than the proximal end 11b of the sheath 11 in a state where the electrode unit 30 is inserted into the sheath 11. That is, the operation unit 40 is positioned outside the subject in a state where the distal end 11a of the sheath 11 and the electrode support 32 of the electrode unit 30 are inserted into the subject.

The operation portion 40 is movable relative to the base end hard portion 31. The operation portion 40 moves relative to the proximal hard portion 31, thereby moving the electrode 35 relative to the distal hard portion 36.

The configurations of the electrode support portion 32, the electrode 35, and the operation portion 40 will be described in detail. The electrode support portion 32 of the present embodiment includes 2 distal end hard portions 36. Each distal end hard portion 36 has a columnar shape with a direction along the longitudinal axis L as a longitudinal direction.

The 2 distal end hard portions 36 are arranged at substantially the same positions in the direction along the longitudinal axis L and are arranged apart from each other in the direction along the 1 st axis X (left-right direction). That is, the 2 distal end hard portions 36 are arranged so as to overlap each other when viewed from the direction along the 1 st axis X. Therefore, each of the 2 distal end hard portions 36 has an opposed surface 36a which is a surface opposed to each other in the direction along the 1 st axis X.

Here, the "surfaces facing each other" mean a surface facing substantially in the left direction of the distal end hard portion 36 disposed on the right side and a surface facing substantially in the right direction of the distal end hard portion 36 disposed on the left side. That is, the facing surface 36a is a portion facing the space sandwiched by the 2 distal end hard portions 36. Therefore, the facing surfaces 36a of the 2 distal end hard portions 36 may not have parallel portions.

A hollow portion 36c is formed inside each distal end hard portion 36. As shown in fig. 5, opening 36c1 opens on the inner wall surface on the proximal end side of hollow 36 c. The electric wire 33 and a restricting portion 41 described later are inserted through the insertion opening portion 36c 1.

Further, each distal end hard portion 36 is formed with a through hole 36d penetrating the cavity portion 36c from the facing surface 36 a. The through hole 36d is a hole through which the wire 33 protrudes outside the distal end hard portion 36. The portion of the wire 33 inserted into the through hole 36d serves as a base 35a of the electrode 35. The through hole 36d is an elongated hole having a longitudinal direction (vertical direction) along the 2 nd axis Y.

More specifically, each distal end hard portion 36 is composed of a ceramic tube 32a and a covering portion 38. The ceramic tube 36c and the covering portion 38 have electrical insulation. The ceramic tube 32a has a hollow portion 36c formed therein. The covering portion 38 is a resin hose, and covers the ceramic tube 32 a. The through hole 36d penetrates the ceramic tube 32a and the covering portion 38.

As an example, the electrode support portion 32 of the present embodiment has 2 elastic regions 37. The 2 elastic regions 37 are connected to the base ends of the 2 distal end hard portions 36, respectively. The electrode support portion 32 may be configured to include 1 elastic region 37 connected to the base ends of both the 2 distal end hard portions 36.

The elastic region 37 of the present embodiment is constituted by a covering portion 38 which is a resin hose. In the present embodiment, the covering portion 38 of the distal end hard portion 36 and the covering portion 38 of the elastic region 37 are, for example, the same member that continues in the direction along the longitudinal axis L. The electric wire 33 is inserted through the covering 38 of the elastic region 37. That is, in the present embodiment, the ceramic tube 32a inserted into the covering portion 38 has a function of making the bending rigidity of the distal end hard portion 36 higher than the bending rigidity of the elastic region 37.

The base end hard portion 31 of the present embodiment is constituted by a covering portion 38 which is a resin hose and a metal pipe 31 d. In the present embodiment, the covering portion 38 of the base end hard portion 31 and the covering portion 38 of the elastic region 37 are, for example, the same member that continues in the direction along the longitudinal axis L. The electric wire 33 is inserted through the covering portion 38 of the base end hard portion 31. The metal pipe 31d covers the outer periphery of the covering portion 38. That is, in the present embodiment, the metal pipe 31d has a function of making the bending rigidity of the base end hard portion 31 higher than the bending rigidity of the elastic region 37.

The pair of base portions 35a of the electrode 35 are disposed in the 2 distal hard portions 36, respectively. That is, the electrode 35 is a metal wire 33 that is bridged between the 2 distal end hard portions 36.

The pair of base portions 35a are disposed to protrude along the 1 st axis X from through holes 36d provided in the facing surfaces 36a of the 2 distal end hard portions 36. The pair of base portions 35a are disposed at substantially the same position in the direction along the longitudinal axis L. That is, the pair of base portions 35a protrude from the pair of opposing surfaces 36 so as to approach each other along the 1 st axis X.

The bridging portion 35b connects the distal ends of the pair of base portions 35 a. The bridge portion 35b is curved in a downwardly convex shape from the pair of base portions 35a when viewed in a direction along the longitudinal axis L. As shown in fig. 4 and 5, the top portion 35c of the bridge portion 35b is located below the downward facing lower end surface 36b of the 2 distal end hard portions 36.

The electrode 35 having the above-described structure is exposed to the outside only in the space sandwiched by the 2 distal end hard portions 36 when viewed from the direction along the 2 nd axis Y. In other words, the portion of the electrode 35 exposed to the outside is arranged so as not to overlap with the 2 distal end hard portions 36 when viewed in the direction along the 2 nd axis Y.

Further, as described above, since the through hole 36d through which the base portion 35a is inserted is a long hole having a longitudinal direction along the 2 nd axis Y, the electrode 35 can move relative to the distal end hard portion 36 in the direction along the 2 nd axis Y. When the electrode 35 is moved relative to the distal end hard portion 36 in the direction along the 2 nd axis Y, the amount of protrusion of the top portion 35c of the electrode 35 downward from the lower end surface 36b changes.

The electrode unit 30 of the present embodiment includes the regulating portion 41 disposed in the hollow portion 36c of each distal end hard portion 36. The regulating portion 41 protrudes from the opening portion 36c1 into the hollow portion 36c, and is movable relative to the distal end hard portion 36. The regulating portion 41 moves forward and backward in the direction along the longitudinal axis L with respect to the distal end hard portion 36.

The restriction portion 41 has a connection portion 41a extending toward the proximal end side and inserted through the elastic region 37 and the proximal end hard portion 31. The connection portion 41a is connected to the operation portion 40. The restriction portion 41 moves in the hollow portion 36c in accordance with the relative movement of the operation portion 40 with respect to the base end hard portion 31.

The restricting portion 41 is moved relatively to the distal end hard portion 36 in the hollow portion 36c, thereby changing the movable range of the electrode 35 in the projecting direction (vertical direction). The restricting portion 41 of the present embodiment moves forward and backward in the hollow portion 36c in the direction along the longitudinal axis L while contacting the lower surface of the electric wire 33. The larger the amount of protrusion of the regulating portion 41 from the opening 36c1 into the cavity 36c, the narrower the movable range of the wire 33 in the vertical direction, and the amount of protrusion of the electrode 35 downward from the lower end surface 36b changes.

Fig. 6 shows a state in which the regulating portion 41 is located closest to the proximal end side with respect to the distal end hard portion 36. Fig. 7 shows a state in which the regulating portion 41 is located at the most distal end side with respect to the distal end hard portion 36. In the electrode unit 30 of the present embodiment, when the operation portion 40 is moved toward the proximal end side relative to the proximal end hard portion 31, the restriction portion 41 is moved toward the proximal end side relative to the distal end hard portion 36. In the electrode unit 30 of the present embodiment, when the operation portion 40 is moved toward the distal end side relative to the proximal end hard portion 31, the restriction portion 41 is moved toward the distal end side relative to the distal end hard portion 36.

Fig. 6 and 7 show a state in which the lower end surface 36b of the distal end hard portion 36 is in contact with the tissue. When the lower end surface 36b of the distal end hard portion 36 is brought into contact with the tissue, the elastic region 37 connected to the proximal end of the distal end hard portion 36 is bent so as to be convex downward. By bending the elastic region 37, a force is applied to the electric wire 33 protruding from the elastic region 37 into the cavity 36c to move the tip downward with the opening 36c1 as a fulcrum. An electrode 35 is connected to the tip of the wire 33 in the hollow portion 36 c. Therefore, as shown in fig. 6 and 7, when the lower end surface 36b of the distal end hard portion 36 is brought into contact with the tissue, the electrode 35 is located at the lower end within the movable range that moves in the vertical direction with respect to the distal end hard portion 36.

Here, as shown in fig. 6, if the restricting portion 41 that contacts the lower side of the electric wire 33 is located closest to the proximal end side, the movable range of the tip end of the electric wire 33 in the hollow portion 36c in the vertical direction is widest. On the other hand, as shown in fig. 7, when the restricting portion 41 moves toward the tip end side, the restricting portion 41 enters below the electric wire 33 in the hollow portion 36c, and therefore, the movable range of the tip end of the electric wire 33 in the vertical direction is narrowed. Specifically, when the restricting portion 41 moves toward the distal end side, the lower end of the movable range of the distal end of the electric wire 33 in the hollow portion 36c moves upward. The movable range of the tip of the wire 33 in the hollow portion 36c is a movable range in which the electrode 35 moves in the vertical direction with respect to the tip hard portion 36.

Therefore, in the present embodiment, as shown in fig. 6, when the restriction portion 41 is located closest to the proximal end side, the amount of protrusion of the top portion 35c of the electrode 35 downward from the lower end surface 36b is maximized. In the present embodiment, as shown in fig. 7, the amount of protrusion of the top portion 35c of the electrode 35 downward from the lower end surface 36b decreases as the restricting portion 41 moves toward the distal end side.

The operation portion 40 is disposed in the base end hard portion 31. The operation portion 40 is located closer to the proximal end side than the proximal end 11b of the sheath 11 in a state where the electrode unit 30 is inserted into the sheath 11. That is, the operation unit 40 is positioned outside the subject in a state where the distal end 11a of the sheath 11 and the electrode support 32 of the electrode unit 30 are inserted into the subject.

The operation portion 40 is movable relative to the base end hard portion 31. The operation portion 40 moves relative to the proximal hard portion 31, thereby moving the electrode 35 relative to the distal hard portion 36, and changing the amount of protrusion of the top portion 35c of the electrode 35 downward from the lower end surface 36 b.

As described above, in the electrode unit 30 of the present embodiment, the amount of protrusion of the top portion 35c of the electrode 35 from the lower end surface 36b of the distal end hard portion 36 can be changed by moving the operation portion 40.

Fig. 8, 9, and 10 are schematic diagrams showing a case where a tissue in an organ 100 of a subject is excised using the electrode unit 30 and the endoscope system 1 of the present embodiment.

When the tissue in the organ 100 is excised using the electrode unit 30, the user first puts the electrode support portion 32 in a posture in which the lower end surface 36b of the distal end rigid portion 36 faces the tissue in the organ 100. Then, as shown in fig. 8, the user brings the electrode support portion 32 into contact with the wall surface of the organ 100, and brings the electrode 35 protruding from the lower end surface 36b of the distal end hard portion 36 into contact with the tissue. The method of inserting the electrode unit 100 and the sheath 11 of the resectoscope 10 into the organ 100 and the method of filling the organ 100 with the perfusate are the same as those of the conventional electrode unit, and therefore, the description thereof is omitted.

Next, the user operates the switch 55a to start outputting the high-frequency current from the high-frequency power supply control device 55. Thus, since the high-frequency current flows from the electrode 35 toward the collecting electrode 11c through the perfusate, the tissue in contact with the electrode 35 generates heat, and the tissue is cut. After the tissue starts to be cut by the output of the high-frequency current, as shown in fig. 9, the electrode 35 enters the tissue.

Here, as described above, the electrode 35 is disposed so as not to overlap the distal end hard portion 36 when viewed from the direction (downward) along the 2 nd axis Y. Therefore, when the electrode 35 enters a predetermined depth in the tissue, the distal end hard portion 36 comes into contact with the tissue that is not cut by the electrode 35. Therefore, in the present embodiment, even if the force with which the user presses the electrode support portion 32 against the wall surface of the organ 100 changes, the electrode 35 can be prevented from further entering the tissue from the state in which the distal end hard portion 36 is in contact with the tissue.

Then, as shown in fig. 10, the user moves the resectoscope 10 and moves the electrode support 32 along the wall surface of the organ 100. In this way, the electrode 35 moves in the direction along the wall surface in the tissue, and therefore, a tissue piece having a predetermined thickness is cut.

Here, as described above, even if the force with which the user presses the electrode support portion 32 against the wall surface of the organ 100 changes, the depth of the electrode 35 entering the tissue is kept constant. Even when the user does not move the resectoscope 10 along the shape of the wall surface of the organ 100 and the distance between the wall surface of the organ 100 and the distal end 11a of the sheath 11 changes, the distal end hard portion 36 is elastically deformed to be in contact with the tissue in the present embodiment. Further, if the distal end hard portion 36 is in contact with the tissue, the depth of the electrode 35 entering the tissue is also kept constant as described above.

As described above, the electrode unit 30 and the endoscope system 1 according to the present embodiment can maintain the depth of the electrode 35 into the tissue to be constant even when the trajectory along which the user moves the electrode 35 is unstable or when the force applied to the electrode 35 by the user varies.

In the electrode unit 30 and the endoscope system 1 according to the present embodiment, the user can change the amount by which the top portion 35c of the electrode 35 protrudes from the lower end surface 36b of the distal end rigid portion 36 by operating the operation portion 40 located outside the subject. That is, the electrode unit 30 and the endoscope system 1 according to the present embodiment can easily change the depth of the electrode 35 into the tissue by the user operating the operation portion 40.

Therefore, according to the electrode unit 30 and the endoscope system 1 of the present embodiment, the thickness of the tissue to be excised can be easily controlled.

(embodiment 2)

Embodiment 2 of the present invention will be described below. Hereinafter, only the differences from embodiment 1 will be described, and the same components as those of embodiment 1 will be denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

The electrode unit 30 of embodiment 2 is different from that of embodiment 1 in structure. The electrode unit 30 of embodiment 2 shown in fig. 11 and 12 includes a proximal end hard portion 31, an electrode support portion 32, an electrode 35, an operation portion 40, and a conversion portion 43.

The proximal end hard portion 31 is a portion fixed to the electrode unit holding portion 23 of the resectoscope 10, as in embodiment 1. An electrode support portion 32 is coupled to the distal end 31a of the proximal end hard portion 31. Further, an electrical connection portion 31c is provided at the base end 31b of the base end hard portion 31.

The electrode support portion 32 includes 1 or 2 distal end hard portions 36 and 1 or 2 elastic regions 37 connected in a direction along the longitudinal axis L. In the present embodiment, as an example, the electrode support portion 32 includes 2 distal end hard portions 36 and 2 elastic regions 37, as in embodiment 1. That is, each of the 2 distal end hard portions 36 has an opposed surface 36a which is a surface opposed to each other in the direction along the 1 st axis X. The metal wire 33 is inserted through the base end hard portion 31, the elastic region 37, and the distal end hard portion 36.

The electrode 35 protrudes from the distal end hard portion 36. The electrode 35 is connected to the wire 33 in the distal end hard portion 36. In the present embodiment, the wire 33 and the electrode 35 are formed of the same metal wire member, for example. The top portion 35c of the electrode 35 protrudes downward from the lower end surface 36b of the distal end hard portion 36 along the 2 nd axis Y.

A hollow portion 36c is formed inside each distal end hard portion 36. Opening 36c1 opens on the inner wall surface on the proximal end side of hollow 36 c. The electric wire 33 passes through the insertion opening portion 36c 1.

Further, a conversion portion 43 having an elongated hole shape is formed in each distal end hard portion 36. The converting portion 43 is a through hole that penetrates in the direction along the 1 st axis X so as to communicate from the facing surface 36a to the cavity portion 36 c.

Further, the conversion portion 43 as an elongated hole is inclined in the longitudinal direction with respect to the longitudinal axis L when viewed from the direction along the 1 st axis X. In the present embodiment, as an example, the conversion portion 43, which is an elongated hole, is inclined with respect to the longitudinal axis L so as to be directed upward toward the base end side when viewed from the direction along the 1 st axis X. That is, when viewed from the direction along the 1 st axis X, the longitudinal direction of the converting portion 43, which is an elongated hole, intersects both the protruding direction (downward) of the electrode 35 and the longitudinal axis L.

The pair of base portions 35a of the electrode 35 are inserted through the conversion portion 43 opened to the facing surfaces 36a of the 2 distal end hard portions 36.

The operation portion 40 is movable relative to the base end hard portion 31. The operation portion 40 of the present embodiment transmits a force to the electrode 35 that moves in a direction along the longitudinal axis L with respect to the distal end hard portion 36.

Specifically, the operation unit 40 of the present embodiment is coupled to the electric wire 33. The wire 33 moves in the electrode unit 30 in the direction along the longitudinal axis L in accordance with the relative movement of the operating portion 40 with respect to the base end hard portion 31. As described above, since the electrode 35 is connected to the distal end of the wire 33, the electrode 35 moves in the direction along the longitudinal axis L with respect to the distal end hard portion 36 as the operation portion 40 moves relative to the base end hard portion 31.

The base portion 35a of the electrode 35 is inserted through a conversion portion 43, which is a long hole whose longitudinal direction is inclined with respect to the longitudinal axis L. Therefore, when a force is applied from the operation unit 40 to the electrode 35, the switching unit 43 functions as a cam hole that switches the direction of the force transmitted from the operation unit 40 to the electrode 35.

The conversion unit 43 of the present embodiment converts the direction of the force along the longitudinal axis L applied from the operation unit 40 to the electrode 35 into a direction intersecting both the protruding direction (downward) of the electrode 35 and the longitudinal axis L.

Specifically, when the operation unit 40 moves toward the base end side, the electrode 35 moves toward the base end side and upward along the converting unit 43 when viewed from the direction along the 1 st axis X. In this case, as the operation portion 40 moves toward the proximal end side, the amount of protrusion of the top portion 35c of the electrode 35 downward from the lower end surface 36b becomes smaller. Fig. 11 shows a state in which the operation portion 40 is located on the most proximal side of the movable range.

Further, when viewed from the direction along the 1 st axis X when the operation portion 40 moves toward the distal end side, the electrode 35 moves toward the distal end side and downward along the converting portion 43. In this case, as the operation portion 40 moves toward the distal end side, the amount of protrusion of the top portion 35c of the electrode 35 downward from the lower end surface 36b increases. Fig. 12 shows a state in which the operation portion 40 is located on the most proximal side of the movable range.

As described above, the electrode unit 30 of the present embodiment includes: an operation unit 40 that pushes and pulls the electrode 35 along the longitudinal axis L; and a conversion portion 43 as a cam that converts the moving direction of the electrode 35 into a direction inclined with respect to the longitudinal axis L when viewed from the direction along the 1 st axis X.

In the electrode unit 30 of the present embodiment, the amount of protrusion of the top portion 35c of the electrode 35 from the lower end surface 36b of the distal end hard portion 36 can be changed by moving the operation portion 40. That is, the electrode unit 30 and the endoscope system 1 according to the present embodiment can easily change the depth of the electrode 35 into the tissue by the user operating the operation portion 40.

In addition, as in embodiment 1, the electrode unit 30 and the endoscope system 1 of the present embodiment in which the electrode supporting portion 32 includes the distal end hard portion 36 and the elastic region 37 can maintain a constant depth of the electrode 35 into the tissue even when the trajectory along which the user moves the electrode 35 is unstable or when the force applied to the electrode 35 by the user varies.

(embodiment 3)

Embodiment 3 of the present invention will be described below. Hereinafter, only the differences from embodiment 2 will be described, and the same components as those of embodiment 2 will be denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

The electrode unit 30 according to embodiment 3 shown in fig. 13 differs from embodiment 2 in the configurations of the distal end hard portion 36, the electrode 35, and the conversion portion 43.

The distal end hard portion 36 is formed with a through hole 36d penetrating the cavity portion 36c from the lower end surface 36 b. The base portion 35a of the electrode 35 is inserted through the insertion through hole 36 d. That is, in the present embodiment, the base portion 35a of the electrode 35 protrudes downward from the lower end surface 36b of the distal end hard portion 36.

The transition portion 43 is a slope formed in the hollow portion 35. A transition portion 43 as a slope is formed on the inner wall surface on the tip end side of the hollow portion 36 c. The converting portion 43 is inclined with respect to the 2 nd axis Y and the longitudinal axis L so as to be directed downward toward the base end side when viewed from the direction along the 1 st axis X. The conversion portion 43 is disposed at a portion where the base portion 35a of the electrode 35 abuts when the electrode 35 moves toward the distal end side in the hollow portion 35.

When the operating portion 40 is located at the end portion of the movable range closest to the base end side, as shown by the solid line in fig. 13, the base portion 35a of the electrode 35 is separated from the converting portion 43. In a state where the base portion 35a is separated from the switch portion 43, the longitudinal direction of the base portion 35a is substantially parallel to the 2 nd axis Y when viewed from the direction along the 1 st axis X. In other words, the longitudinal direction of the base 35a is substantially orthogonal to the longitudinal axis L. That is, in a state where the operation portion 40 is located at the end portion of the movable range closest to the base end side, the top portion 35c of the electrode 35 protrudes in a direction substantially orthogonal to the lower end surface 36b of the distal end hard portion 36. In this case, the shortest distance from the lower end surface 36b to the top 35c of the electrode 35 becomes longest.

When the operation portion 40 is located at the end of the movable range closest to the distal end, the base portion 35a of the electrode 35 is in an attitude in which the longitudinal direction is inclined with respect to the 2 nd axis Y and the longitudinal axis L along the conversion portion 43, as shown by the two-dot chain line in fig. 13. That is, the converting portion 43 as an inclined surface converts the direction of the force transmitted from the operation portion 40 to the electrode 35, and moves the base portion 35a substantially orthogonal to the longitudinal axis L in a direction inclined in the direction along the longitudinal axis L.

In a state where the operation portion 40 is located at the end portion of the movable range closest to the distal end side, the top portion 35c of the electrode 35 protrudes from the lower end surface 36b of the distal end hard portion 36 in a direction inclined with respect to the 2 nd axis Y. In this case, the shortest distance from the lower end surface 36b to the top portion 35c of the electrode 35 becomes shortest.

As described above, the electrode unit 30 of the present embodiment includes: an operation unit 40 that pushes and pulls the electrode 35 along the longitudinal axis L; and a converting section 43 that converts the moving direction of the top portion 35c of the electrode 35 into a direction intersecting the longitudinal axis L when viewed from the direction along the 1 st axis X.

In the electrode unit 30 of the present embodiment, the amount of protrusion of the top portion 35c of the electrode 35 from the lower end surface 36b of the distal end hard portion 36 can be changed by moving the operation portion 40. That is, the electrode unit 30 and the endoscope system 1 according to the present embodiment can easily change the depth of the electrode 35 into the tissue by the user operating the operation portion 40.

In addition, as in embodiment 1, the electrode unit 30 and the endoscope system 1 of the present embodiment in which the electrode supporting portion 32 includes the distal end hard portion 36 and the elastic region 37 can maintain a constant depth of the electrode 35 into the tissue even when the trajectory along which the user moves the electrode 35 is unstable or when the force applied to the electrode 35 by the user varies.

The present invention is not limited to the above-described embodiments, and can be appropriately modified within a range not departing from the spirit or concept of the invention read from the claims and the entire specification, and an electrode unit and an endoscope system associated with such modification are also included in the technical scope of the present invention.