JP2009090003A - High-frequency treatment instrument for endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve efficiency and safety of treatment by holding an electrode member stably at a predetermined position in accordance with the kind and characteristic of treatment with a high-frequency treatment instrument inserted into a treatment instrument insertion channel of an endoscope. <P>SOLUTION: Click engaging sections 16R, 16M, 16F16 each having front and rear inclined walls 16a and 16a are formed integrally with the inner surface of a distal side of a flexible sheath 2. A flange section 17 is fixed to a position near a connecting part between a flexible cord 11 and the electrode member 13. When the flange section 17 engages with the click engaging section 16R, the electrode member 13 moves to a retracted position where the whole electrode member is retracted to the inside of the flexible sheath 2. When the flange section engages with the click engaging section 16F, the electrode member 13 moves to a first operating position where the electrode member is led farthest out of the distal end of the flexible sheath 2. When the flange section engages with the click engaging section 16M located in the middle, the distal end of the electrode member 13 is held at a position where the distal end of the electrode member projects slightly from the distal surface of the flexible sheath 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is inserted into a treatment instrument insertion channel of an endoscope, for example, coagulation for hemostasis on the inner wall of a body cavity or marking by cauterization, and incision and peeling of a lesion mucosa portion. The present invention relates to a high-frequency treatment instrument that can smoothly perform a complex treatment such as a removal treatment.

  When a lesioned part such as a tumor is found in the mucosal part of the inner wall of a body cavity such as the esophagus, stomach, duodenum, and large intestine by endoscopy, a treatment for excising the mucous membrane is performed. One of the treatments is a treatment called endoscopic submucosal dissection (ESD). In this ESD treatment, first, a mucosal site to be excised is marked, and the lesioned mucosal site is bulged by local injection, and then the mucous membrane is incised and peeled along the outside of the marking. Here, the marking on the mucous membrane and the incision and peeling of the mucous membrane can be performed using a high-frequency treatment instrument having a rod-shaped electrode member. In addition, when a bleeding site is detected in a body cavity during an examination using an endoscope and during the predetermined ESD treatment described above, the bleeding part is coagulated by cauterization. This coagulation treatment can also be performed with a high-frequency treatment instrument having a rod-shaped electrode member.

  The high-frequency treatment instrument that performs the above-described treatment is inserted into a body cavity using a treatment instrument insertion channel of an endoscope as a guide means, and a flexible sheath is led out from the distal end of the treatment instrument insertion channel. By causing the electrode member to be led out and energizing the electrode member, treatment such as mucosal cauterization or incision is performed. Normally, the electrode member is retracted into the flexible sheath while the treatment is not being performed, such as when being inserted into the treatment instrument insertion channel of the endoscope, and the electrode member is flexed immediately before the treatment is performed. Operate so that it is led out from the distal end of the sheath.

  As described above, when the treatment is not performed, since the electrode member is located inside the flexible sheath, there is no particular risk. However, in order to perform the treatment, the electrode member is removed from the flexible sheath. After being led out, handling must be done carefully so that accidents such as perforation of the inner wall of the body cavity do not occur. Here, usually, the treatment can be performed more efficiently by increasing the lead-out length of the electrode member from the flexible sheath. However, if the electrode member is led out longer than necessary, the electrode member may be inserted to a position deeper than the submucosa, causing damage to healthy body tissue and causing inconveniences such as perforation of the body cavity inner wall. .

  Therefore, in Patent Document 1, a locking ring is provided at the distal end portion of the flexible sheath, and the electrode member is smaller than the inner diameter of the locking ring described above, and the outer peripheral portion on the proximal end side of the electrode member In addition, there is disclosed a configuration in which the lead-out length of the electrode member is limited by providing a stopper portion having an outer diameter larger than the inner diameter of the ring. The longest lead-out length of the electrode member is regulated by a locking ring provided at the tip of the flexible sleeve and a stopper provided on the electrode member. Is provided by screwing, and by making it possible to adjust the protruding length of the extension cylinder part, it is possible to adjust the lead-out length of the electrode member from the tip of the extension cylinder part, It is disclosed in Patent Document 2.

Furthermore, in Patent Document 3, the electrode member is inserted into the contact coil, and the length of the electrode member led out from the flexible sheath tip is adjusted by adjusting the protruding length of the electrode member from the contact coil. It can be adjusted. Furthermore, in Patent Document 4, a screw ring whose inner surface is a threaded portion is provided at the tip of an operation wire made of a conductive member, and an electrode member is screwed into the screw ring. By doing so, it is possible to adjust the lead-out length of the electrode member from the distal end of the flexible sheath.
JP 2002-153484 A JP 2002-1113016 A JP 2007-1111148 A JP 2007-111149 A

  In each of the aforementioned patent documents, the electrode member can be displaced between a retracted state in which the electrode member is drawn into the flexible sheath and a most derived state in which the distal end is most derived from the distal end surface of the flexible sheath. ing. And although it can arrange | position in the intermediate position, it cannot hold | maintain an electrode member in a specific position. For example, if there is a bleeding part on the inner wall of the body cavity, the electrode member is actuated for hemostasis to cause coagulation, and this coagulation treatment causes the electrode member to be positioned at approximately the same position as the distal end of the flexible sheath. It is most desirable to hold the position slightly led out from the viewpoint of the safety and efficiency of the treatment. However, in each of the above-mentioned patent documents, all of the electrode members are stably positioned while the bleeding portion is coagulated in a state where a predetermined length is derived from the flexible sheath or a predetermined treatment is performed. It is not configured to be held in. In addition, the high-frequency treatment instrument shown in each of these patent documents needs to be extracted from the treatment instrument insertion channel of the endoscope and adjusted in accordance with the treatment mode.

  The need to stably hold the electrode member in the intermediate state between the retracted state and the most derived state is necessary not only for the coagulation of the bleeding part described above but also for marking the site to be incised. Become. Since this marking cauterizes the inner wall of the body cavity, a high-frequency treatment instrument can be used, but it is desirable that the electrode member be located at substantially the same position as the distal end surface of the flexible sheath.

  Further, a stopper mechanism for holding the electrode member at a predetermined position in the retracted state of the electrode member is not specially provided. For this reason, when the electrode member is held in the retracted state and slightly pulled into the flexible sheath, the flexible sheath is wound into a small loop or the like. Depending on the state, the electrode member that is in the retracted state may be displaced and may be led out from the tip of the flexible sheath. On the other hand, in the most lead-out state of the electrode member, operations such as incision and peeling of the mucous membrane are performed. In this operation, the stopper portion provided on the electrode member is the base end surface of the locking ring provided on the flexible sleeve. It does not have a mechanism for holding in this most derived state. Therefore, in order to hold the electrode member in the most derived state, the operation member connected to the proximal end portion of the flexible sheath must be always held in the most derived state. In addition, there is a problem that operability as a treatment tool is poor.

  The present invention has been made in view of the above points. The object of the present invention is to provide an electrode member in a state in which a treatment instrument is inserted into a treatment instrument insertion channel according to the type and nature of the treatment. It is an object of the present invention to provide a high-frequency treatment instrument that can be stably held in a position and that improves the efficiency and safety of treatment.

  In order to achieve the above-described object, the present invention provides an electrode member that is provided in a flexible sheath that is inserted into a treatment instrument insertion channel of an endoscope and that can apply a high-frequency current to the distal end of the flexible cord. An operation member is connected to the proximal end portion of the flexible cord, and the operation member is used to perform an operation of projecting and retracting the electrode member from the distal end of the flexible sheath. In the flexible sheath, a click locking portion is provided in at least one place, and the electrode member or a connecting portion between the electrode member and the flexible cord is engaged with the click locking portion. The feature is that a click protrusion is provided.

  The rod-shaped electrode member inserted into the flexible sheath and connected to the flexible cord is moved against the flexible sheath by the operation of the operating member connected to the proximal end of the flexible sheath. Infested. The electrode member has a standby position retracted into the flexible sheath and a first operating position most derived from the flexible sheath. In addition, at least the flexible sheath Another operating position is provided which is led out by a minute amount from a position almost the same as the tip of the wire or a position slightly seen from the flexible sheath. In order to stably hold the electrode member at least in any one of these positions, at least one click locking portion is provided on the flexible sheath side, and one click projection is provided on the electrode member side. For example, click locking portions are provided at three locations. When the click protrusion engages with the click locking portion at the most proximal end, the electrode member is in a retracted position to be held in a state of being pulled into the flexible sheath, and the click protrusion is at the click locking portion at the most distal end. When engaged, the electrode member is restricted to the first operating position where it protrudes most from the flexible sheath, and one or a plurality of click locking portions provided between the most proximal end portion and the most distal end portion are provided. When the click protrusion is engaged, the electrode member is located at the position facing the distal end of the flexible sheath, that is, the position of the distal end of the flexible sheath or a position slightly derived therefrom. Furthermore, this can be used as the second operating position, and further third and fourth operating positions can be provided.

Unless the operation member is pushed and pulled, the electrode member is stably held at the above-described positions. Specifically, even when the operation member is released, the electrode member is held so as not to become unstable. On the other hand, when the operation member is operated, the holding force is set so as to be relatively easily detached from each click locking position. The click mechanism based on the engagement between the click locking portion and the click protrusion can hold the electrode member at each click locking position. Will be moved. When this electrode member is strongly pressed against the inner wall of the body cavity in a state where the electrode member is led out from the distal end of the flexible sheath, this pressing force causes the electrode member to be prevented from being perforated. It is desirable to be drawn into the flexible sheath side. For this purpose, for example, when an external force of 10 N (kg · m / s ² ) or more is applied, the engagement by the click locking portion can be set to be released.

  As a specific configuration of the click locking portion provided on the flexible sheath side, it is configured by an annular V groove formed on the inner surface of the flexible sheath or the inner surface of the hard sleeve provided inside the flexible sheath. can do. On the other hand, a click protrusion is provided at the base end side position of the electrode member. And at least any one of a click latching | locking part or a click protrusion is comprised with an elastic member. Since the flexible sheath is made of a soft resin and has elasticity in itself, the click projection side may be provided integrally with a hard member, for example, an electrode member. When a flexible sleeve is attached to the flexible sheath, the click projection side has elasticity, that is, a structure that can be displaced in a direction perpendicular to the axis of the electrode member. The flexible sheath is provided with a stopper that restricts the electrode member to a limit lead-out position from which the electrode member does not lead any further. The stopper is preferably formed by being inserted into a flexible sheath, and is composed of an electrode member or a hard member that engages with a member provided so as to protrude radially from the electrode member. Moreover, the click protrusion of the click latching | locking part in the front side of a 1st operation position can also serve as a stopper.

  Further, in the flexible sheath, the click projections provided at least at three positions in the axial direction may have the same holding force for the electrode member, but the holding force is changed depending on each part. You can also In particular, when the height dimension of the click locking portion at the other operation position located in the middle is set lower than that of the click locking portion between the retracted position and the first operating position, In some cases, the performance is further improved.

  By adopting the above configuration, depending on the type and nature of the treatment, in a state of being inserted through the treatment instrument insertion channel of the endoscope, it is stable at least in a derived state shorter than the most derived state of the electrode member in the high-frequency treatment instrument. The efficiency and safety of the treatment can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, FIG. 1 shows the overall configuration of the high-frequency treatment instrument, and FIG. In the figure, reference numeral 1 denotes a high-frequency treatment instrument. This high-frequency treatment instrument 1 has a long flexible sheath 2, and a connection pipe 3 is connected to the proximal end portion of the flexible sheath 2. Further, the operation means 4 is connected to the other end of the connection pipe 3. The operating means 4 includes a main body shaft 4a connected to the connection pipe 3, and a slider 4b fitted to the main body shaft 4a and provided to be slidable in the axial direction of the main body shaft 4a. A base end portion of a flexible cord 11 constituting the treatment instrument main body 10 is connected to the slider 4b. The flexible cord 11 is configured by covering the outer periphery of the conductive wire with an electrically insulating member by coating with a fluororesin or the like, and its base end portion protrudes a predetermined length from the connecting portion to the slider 4b, and contacts A portion 12 is provided. Accordingly, the contact portion 12 is detachably connected to a high frequency power supply device (not shown).

  As is clear from FIG. 2, the flexible cord 11 constituting the treatment instrument body 10 extends from the connecting portion to the slider 4 b through the inside of the connecting pipe 3 and into the flexible sheath 2. A conductive wire extends in a straight line from the distal end portion of the flexible cord 11, and a lead-out portion of the conductive wire is an electrode member 13 constituting a needle knife. In addition, a heat insulating member 14 is inserted into the distal end portion of the flexible sheath 2, and the heat insulating member 14 that performs the linear guide function of the electrode member 13 and the heat shielding function to the flexible sheath 2 is, for example, It consists of hard rings, such as a ceramic, The front end surface is arrange | positioned in the same position as the front end surface of the flexible sheath 2, and is fixed by means, such as adhesion | attachment. An insertion hole 15 penetrating in the axial direction is formed at the position of the central axis of the heat insulating member 14, and the diameter of the insertion hole 15 is slightly larger than the outer diameter of the electrode member 13. Therefore, the distal end reference surface P having a large area is formed by the distal end surface of the heat insulating member 14 and the distal end surface of the flexible sheath 2. Further, the proximal end portion of the heat insulating member 14 is formed with a calling taper portion 14 a (see FIG. 3) facing the insertion hole 15.

  FIG. 3 shows an enlarged cross section of the distal end portion of the flexible sheath 2. The flexible sheath 2 is composed of a resin tube having elasticity, and as a specific example, a fluororesin (PTFE), a polyetheretherketone resin (PEEK), a polyethylene resin, or the like is preferably used. On the inner surface on the distal end side of the flexible sheath 2, click locking portions 16 are integrally formed at three front and rear positions. These three click locking portions 16 are formed of an annular V-shaped groove, and the bottom of the groove is located at the same position as the inner peripheral surface of the flexible sheath 2. The front and rear inclined wall portions 16a and 16a constituting the V groove protrude inward in the radial direction. Here, the protruding height of the inclined wall portion 16a is such that the electrode member 13 can be inserted into the inclined wall portion 16a and a minimum gap is formed therebetween.

  A flange portion 17 formed integrally with the electrode member 13 is fixed to the click locking portion 16 at the proximal end side of the electrode member 13, that is, in the vicinity of the connection portion of the electrode member 13 with the flexible cord 11. Is provided. The flange portion 17 has a shape in which the front and rear portions are continuously thinned from the side fixed to the electrode member 13, and the cross-sectional shape thereof is substantially the same shape as the V groove constituting the click locking portion 16. Thus, the click locking portion 16 is slightly wider. Moreover, the front-end | tip shape of the flange part 17 is a rounded and unsharp state.

  The click locking part 16 is formed in three places. Therefore, in the click locking portions 16, when the click locking portions are collectively referred to, the reference numeral 16 is used as shown in FIG. 2, and in order to distinguish what is provided at each position, FIG. As shown in FIG. 5, the signs 16R, 16M, and 16F are used in order from the proximal end side of the flexible sheath 2, that is, the inner back side.

  3 to 5 show a state in which the flange portion 17 provided on the electrode member 13 is held at each position. FIG. 3 shows a state in which the flange portion 17 of the electrode member 13 is engaged with a click locking portion 16 </ b> R provided at the proximal end position on the inner surface of the flexible sheath 2. The entirety is held in the retracted position drawn into the flexible sheath 2. At this time, the flange portion 17 provided on the electrode member 13 is sandwiched between the inclined wall portions 16a and 16a of the click locking portion 16R, whereby the electrode member 13 is stably held at the retracted position. The In this retracted position, the electrode member 13 is positioned on the proximal end side with respect to the heat insulating member 14.

  When the flexible cord 11 of the treatment instrument main body 10 is pushed and pulled by the operating means 4, the flange portion 17 pushes the inclined wall portion 16a of the click locking portion 16 to move the inclined wall portion 16a made of an elastic member. The robot can get over while being elastically deformed and can move back and forth in the flexible sheath 2. FIG. 4 shows the first operating position where the electrode member 13 is most led out from the distal end of the flexible sheath 2. In the first operating position, the flange portion 17 of the electrode member 13 is engaged with the click locking portion 16F. Further, in FIG. 5, the flange portion 17 provided on the electrode member 13 is engaged with the click locking portion 16 </ b> M located in the middle, and the distal end of the electrode member 13 is slightly from the distal end surface of the flexible sheath 2. Is held at the position where it is derived. This position is the second operating position of the electrode member 13.

  The click locking portion 16 is formed integrally with the flexible sheath 2. These three click locking portions 16 can be formed by molding means, but the flexible sheath 2 is formed by a thick tube, and then a pressure is applied in a heated state from the outer peripheral side of the tube. Thus, annular protrusions are formed on the inner surface side in the front-rear direction, and a portion therebetween becomes a V-shaped groove. Thus, by adopting pressure molding performed under heating, the outer surface of the flexible sheath 2 has an uneven shape, but the click locking portion 16 is easily formed.

  The high-frequency treatment instrument 1 having the above configuration is inserted into a body cavity via a treatment instrument insertion channel provided in an endoscope insertion portion, and a bleeding site is found in a body cavity inner wall such as the esophagus, stomach, duodenum, and large intestine. If present, hemostasis can be achieved by coagulating the bleeding site. When a lesion mucosa such as a tumor exists, a treatment for peeling and removing the lesion mucosa, that is, an ESD treatment is performed. In performing this treatment, the mucous membrane is marked in advance, then incised along the marking, and the incised mucosa is peeled off.

  First, a treatment for cauterizing and coagulating the bleeding site on the inner wall of the body cavity will be described. The high-frequency treatment instrument 1 is inserted into the treatment instrument insertion channel at a stage before the insertion portion of the endoscope is inserted into the body cavity or at a stage where a bleeding site is found. When performing this insertion operation, the electrode member 13 is configured so that the flange portion 17 provided on the electrode member 13 is engaged with the click locking portion 16R of the flexible sheath 2, so that the electrode member 13 is brought into the retracted position. Keep it. Since the electrode member 13 has a small diameter and is formed of a metal material, it has a needle shape. If the electrode member 13 protrudes from the distal end of the flexible sheath 2, the inner surface of the treatment instrument insertion channel is damaged. Or when protruding from the treatment instrument insertion channel, the inner wall of the body cavity may be damaged.

  By setting the electrode member 13 to the retracted position, the distal end surface of the flexible sheath 2 is an annular distal end reference surface P having a wide surface. Therefore, the flexible sheath 2 advances smoothly through the treatment instrument insertion channel without damaging the inner surface. The distal end of the flexible sheath 2 reaches the outlet of the treatment instrument insertion channel. Even if the flexible sheath 2 overruns and the distal end protrudes from the outlet, the inner wall of the body cavity may be damaged. Absent. Since the electrode member 13 is stably held by the click locking portion 16R, there is a possibility that the electrode member 13 may protrude from the tip reference plane P even if the flexible sheath 2 is bent in a complicated manner. It is held stably.

  Under observation through an observation window provided in the endoscope insertion portion, the bleeding site is confirmed, and the outlet of the treatment instrument insertion channel faces this bleeding site. In this state, the flexible sheath 2 is pushed out, the tip reference surface P is brought into contact with the body cavity inner wall, the slider 4b in the operation means 4 is operated, and the flexible cord 11 is pushed. Here, since the inclined wall part 16a which comprises the click latching | locking part 16 can be elastically deformed, the flange part 17 provided in the electrode member 13 currently hold | maintained at the retracted position is the click latching part 16R. The electrode member 13 moves forward in the flexible sheath 2 by overcoming the inclined wall portion 16a on the front side. Then, when the flange portion 17 comes into contact with the inclined wall portion 16a on the rear side of the click locking portion 16M and gets over the inclined wall portion 16a, the electrode member 13 reaches the second end surface facing the distal end surface of the flexible sheath 2. Displaced to the operating position. At this time, the position of the electrode member 13 cannot be confirmed from the outside of the flexible sheath 2, but when the flange portion 17 gets over the inclined wall portion 16a, a feeling of clicking is given to the operator of the operation means 4. Therefore, it can be surely recognized that it has been displaced to the second operating position.

  In this state, the flexible sheath 2 is further advanced, and the tip reference surface P is brought into contact with the body cavity inner wall. At this time, it is desirable that the flexible sheath 2 is merely brought into contact with the inner wall of the body cavity and no pushing force is applied. However, even if it is pushed in to some extent, the tip reference surface P has a large area, and the electrode member 13 is stably held in a non-projecting state, so that there is no particular problem. In this state, when the electrode member 13 is energized, the bleeding part tissue is cauterized and hemostasis is achieved by coagulation.

  When this hemostasis is completed, the flexible sheath 2 is pulled back into the treatment instrument insertion channel. Although not necessarily essential, it is desirable to return the electrode member 13 to the retracted position. At this time, the operator can recognize that the electrode member 13 has escaped from the second operating position and has returned to the retracted position as a click feeling.

  Next, the ESD treatment will be described. First, the marking on the treatment site can be performed by the same operation as the above-described cauterization for hemostasis. In other words, the marking is also performed by cauterizing the body tissue.

  Thereafter, the mucous membrane of the lesion is excised along the outside of the marking. The mucous membrane excision is performed by inserting the electrode member 13 to a position extending from the mucous membrane to the middle of the submucosal layer. After the incision, the electrode member 13 is moved into the exposed portion of the submucosal layer generated by the incision, and the electrode member 13 is moved horizontally or swinged so as to cut the submucosal layer. To remove the mucous membrane. Thereby, the lesioned mucosa is excised.

  When performing this mucosal resection, the electrode member 13 is displaced to the first operating position that is most led out from the flexible sheath 2. Here, the electrode member 13 led out from the flexible sheath 2 must incise the mucous membrane region securely and do not damage the muscle layer located under the mucosa. For this reason, in the first operating position, the lead-out length of the electrode member 13 from the flexible sheath 2 is longer than the thickness dimension of the mucosa layer and shorter than the total thickness dimension of the mucosa layer and the submucosa layer. Set to In addition, before the incision is started, a swelling agent made of physiological saline or sodium hyaluronate is injected to thicken the submucosa and bulge the mucosal surface. As a result, a sufficient distance can be ensured between the excision part and the muscle layer, the tip of the electrode member 13 does not touch the muscle layer, and mucosal resection treatment can be performed without causing any damage to the muscle layer. Done.

  That is, with the electrode member 13 held in the retracted position, the flexible sheath 2 is moved from the opening of the treatment instrument insertion channel of the endoscope insertion portion to the site to be incised. Then, by operating the operating means 4, the electrode member 13 is displaced to the first operating position. At this time, since the transition is made from the retracted position to the first operating position via the second operating position, the flange portion 17 provided on the electrode member 13 is clicked by the click locking portion at the retracted position. After climbing over the inclined wall portion 16a of 16R, it passes over the two inclined wall portions 16a, passes through the click locking portion 16M, and further gets over the inclined wall portion 16a on the proximal end side of the click locking portion 16F. Also at this time, a click feeling is generated, and the position of the electrode member 13 can be recognized. When the electrode member 13 is displaced to the first operating position, the electrode member 13 is led out from the distal end of the flexible sheath 2, so that the electrode member 13 can also be confirmed by observation means in the endoscope insertion portion. is there.

  The stability of the electrode member 13 is required to improve the safety and smoothness of the operation when performing the incision and peeling the mucous membrane that has been incised. Here, since the flange portion 17 fixed to the electrode member 13 is sandwiched by the click locking portion 16F, the movement of the electrode member 13 in the axial direction is restricted, and the front and rear of the click locking portion 16F are inclined. The movement in the direction perpendicular to the axis of the electrode member 13 and the tilt direction is regulated by the wall portion 16 a and the insertion hole 15 of the heat insulating member 14 provided at the distal end of the flexible sheath 2.

  Here, when performing incision or mucosal detachment, the endoscope insertion portion is bent or moved. At this time, if the electrode member 13 becomes unstable, the operation is hindered. However, as described above, since the electrode member 13 is fixedly held in the flexible sheath 2, it is possible to safely operate the electrode member 13 while energizing the electrode member 13, and the efficiency of the treatment. Is achieved. In spite of the electrode member 13 being in the first operating position, the inclined wall portion 16a located on the front side of the click locking portion 16F due to the operating force acting in the direction of pushing the electrode member 13 further. Even if the position is overcome, the flange portion 17 comes into contact with the stopper 14, which is the limit derivation position, and the electrode member 13 is not led out any further.

If the resistance when the flange portion 17 provided on the electrode member 13 gets over the inclined wall portion 16a of the click locking portion 16 is too large, the operability is deteriorated and the electrode member 13 is pressed against the inner wall of the body cavity with a large force. When done, there is a possibility of damaging the inner wall of the body cavity. On the other hand, even if a light force is applied, if the flange portion 17 gets over the inclined wall portion 16a without resistance, the stability of the electrode member 13 cannot be obtained, and a click feeling cannot be obtained. The magnitude of resistance when climbing over the inclined wall portion 16a of the flange portion 17 is determined by the degree of elasticity, the inclination angle, and the height. Accordingly, the holding force at the retracted position of the electrode member 13 and the first and second operating positions is adjusted by appropriately setting the material of the flexible sheath 2 and the shapes of the click locking portion 16 and the flange portion. can do. Specifically, the holding force of the electrode member 13 at each position is preferably about 10 to 20 N (kg · m / s ² ).

  The holding forces of the click locking portions 16R, 16M, and 16F are not necessarily the same, and a difference may be provided between them. For example, the click locking portion 16M located at the second operating position can be set so that a smaller resistance than that of the other click locking portions is generated. Thereby, the transition from the retracted position to the first operating position can be performed smoothly, and for example, the electrode member 13 is placed in the flexible sheath 2 while operating at the first operating position. When it is necessary to pull in quickly, the operation can be performed quickly.

  Next, FIGS. 6 to 8 show a second embodiment of the present invention. In this embodiment, as shown in FIG. 6, the flexible sheath 102 has a uniform tube shape with no unevenness over its entire length, and a hard portion having electrical insulation such as ceramic at the tip portion. A locking ring 100 made of a ring-shaped member is inserted and fixed. The electrode member 113 is connected to the distal end of the flexible cord 111 constituting the treatment instrument main body, and these members are inserted into the flexible sheath 102.

  On the inner surface of the locking ring 100, a pair of front and rear annular click ridges 116a and 116a projecting inward are formed, and the click locking portion 116 is formed by the pair of click ridges 116a and 116a. Is done. The click locking portions 116 are formed at three positions at positions separated in the axial direction of the locking ring 100. As in the first embodiment described above, the click locking portions 116 at these positions are retracted from the proximal end side into the flexible sheath 102 of the electrode member 113 and the flexibility of the electrode member 113. The second operation position substantially coincides with the distal end surface of the sheath 102 and the first operation position where the electrode member 113 is most led out from the flexible sheath 102.

  On the other hand, on the outer peripheral surface on the proximal end side of the electrode member 113, as shown in an enlarged view in FIG. 7, three recesses 113a are formed in the circumferential direction at predetermined intervals, preferably every 120 degrees. A leaf spring 117 is attached to each of the recesses 113a. As shown in FIG. 8, both ends of the leaf spring 117 are fixed to the front and rear wall portions of the recess 113a, and the intermediate portion is in an unfixed state. A click protrusion 117 a that protrudes outward from the outer peripheral surface of the electrode member 113 is formed at an intermediate position of the leaf spring 117.

  Accordingly, when the electrode member 113 is displaced in the axial direction of the flexible sheath 102, the electrode member 113 gets over either of the front and rear click ridges 116a arranged in any of the click locking portions 116R, 116M, or 116F, and becomes a pair of click protrusions. When entering between the strips 116a, 116a, a predetermined holding force is exerted to hold the electrode member 113 in the retracted position, the second operating position, or the first operating position.

  In order to regulate the ultimate lead-out position of the electrode member 113, a large-diameter portion is formed near the base end portion of the electrode member 113, that is, in the vicinity of the connecting portion to the flexible cord 111. It functions as the stopper portion 114. The outer diameter of the stopper portion 114 is larger than the inner diameter of the locking ring 100, and when the stopper portion 114 is led out to a position where it comes into contact with the proximal end portion of the locking ring 100, the electrode member 113 is pushed out further. It will never be. This limit deriving position is a position slightly ahead of the first operating position.

  Here, for example, in order to perform hemostasis treatment, it is necessary to confirm the bleeding site by endoscopic observation means. For this reason, it is desirable that the high-frequency treatment instrument 101 is provided with a cleaning liquid injection means. The flexible cord 111 is inserted into the flexible sheath 102. However, there is a space, and the inside of the flexible sheath 102 can be used as a cleaning liquid supply passage. However, the electrode member 113 is disposed inside the locking ring 100, and there is very little clearance between the inner surface of the locking ring 100 and the electrode member 113. Therefore, one or a plurality of liquid supply paths 105 are provided on the outer peripheral surface of the locking ring 100. As a result, it is also possible to supply a cleaning liquid or the like into the body cavity.

1 is an overall configuration diagram of a high-frequency treatment tool showing an embodiment of the present invention. It is sectional drawing of FIG. It is sectional drawing of the front-end | tip part of a flexible sheath which shows the retracted position of an electrode member. It is sectional drawing of the front-end | tip part of a flexible sheath which shows the 1st operation position of an electrode member. It is sectional drawing of the front-end | tip part of a flexible sheath which shows the 2nd operation position of an electrode member. It is sectional drawing of the front-end | tip part of the flexible sheath which shows the 2nd Embodiment of this invention. It is XX sectional drawing of FIG. It is sectional drawing which shows the leaf | plate spring mounting part of the electrode member in the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 High frequency treatment tool 2,102 Flexible sheath 4 Operation means 10 Treatment tool main body 11, 111 Flexible cord 13, 113 Electrode member 113a Recessed part 14 Heat insulation member 16, 116 Click locking part 116a Click protrusion 17 Flange Part 117 leaf spring 117a click projection

Claims (6)

An electrode member that is provided in a flexible sheath that is inserted into the treatment instrument insertion channel of the endoscope and that can apply a high-frequency current to the distal end of the flexible cord is connected to the proximal end portion of the flexible cord. In a high-frequency treatment instrument that is configured to connect an operation member and to perform an operation of projecting and retracting the electrode member from the distal end of the flexible sheath with this operation member,
Inside the flexible sheath, a click locking portion is provided at least at one place,
A high-frequency treatment instrument for an endoscope, wherein a click protrusion that engages with the click locking portion is provided at a connecting portion between the electrode member or the electrode member and the flexible cord. The click locking portions are provided at least in three locations with an axial interval inside the flexible sheath, and when the click protrusion is engaged with the click locking portion at the most proximal end, the electrode member is When the click projection is engaged with the click locking portion at the most distal portion, the electrode member is in the most projected state from the flexible sheath. When the click protrusion engages with one or more click locking portions provided between the most proximal end portion and the most distal end portion, the electrode member is flexible. The high-frequency treatment instrument for an endoscope according to claim 1, wherein the high-frequency treatment instrument for an endoscope is configured to be held at a position that coincides with a distal end of the sheath or at another operation position having a projection amount shorter than the first operation position. The endoscopic high-frequency treatment instrument according to claim 1 or 2, wherein the other operation position is a position where the electrode member faces a distal end of the flexible sheath. Each of the click locking portions includes a pair of front and rear wall members provided integrally with the inner surface of the flexible sheath, and the click protrusion is formed on the outer peripheral surface of the electrode member. The high-frequency treatment instrument for an endoscope according to any one of claims 1 to 3, wherein the endoscope is configured by a flange portion that can be engaged and disengaged. The click locking portion is composed of a pair of front and rear wall members provided at three locations on the inner surface of a hard sleeve made of an electrically insulating member inserted and fixed in the flexible sheath. 4. The structure according to claim 1, comprising an elastic member formed on an outer peripheral surface of the electrode member, wherein the click protrusion is elastically deformed to be engaged and disengaged between the wall members. The high-frequency treatment tool for endoscopes described in 1. 2. The structure according to claim 1, wherein a stopper is provided between the inner surface of the flexible sheath and the electrode member for restricting a limit derivation position of the electrode member from the flexible sheath. Item 6. The endoscopic high-frequency treatment instrument according to any one of Items 5 to 6.

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