Abstract:
A medical treatment instrument operation unit includes a sliding portion capable of advancing and retracting to a body portion and rotating around a longitudinal axis of the body portion and connected to a proximal end portion of the operating member, and a regulating portion switchable to a movable state where regulating portion is capable of advancing, retracting, and rotating to the body portion and a limited state where the advance, retraction, and rotation of sliding portion to the body portion is limited. The regulating portion includes a rotatable dial portion, and a shaft-shaped member screwed to the dial portion to be relatively advanceable and retractable thereto in a direction in which the shaft-shaped member is brought close to and separated from the body portion. Movable and limited states are switched as the shaft-shaped member comes close to and separates from the body portion with the turning of the dial portion.

Description:
This application is a continuation claiming priority on the basis of Japanese Patent Application No. 2012-179509 filed in Japan on Aug. 13, 2012 and based on PCT/JP2013/071045 filed on Aug. 2, 2013. The contents of both the Japanese Patent Application and the PCT Application are incorporated herein by reference. 
    
    
     The present invention relates to a medical treatment instrument. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a medical treatment instrument. 
     2. Description of Related Art 
     In the related art, medical treatment tools for performing various kinds of treatment on a living body tissue have been studied. 
     For example, a high-frequency knife described in Japanese Patent No. 3923022 includes a sheath, and an operation unit provided at a base end of the sheath. A tubular stopper member is coupled to a tip of the sheath. A conductive operating wire (operating member) is inserted through the inside of the sheath so as to be movable in an axis direction. A distal end portion of the operating wire is mounted with a stopper receiving portion that abuts against the aforementioned stopper member. A knife unit (treatment unit) is connected to the stopper receiving portion. A tip of the knife unit is formed with a bent portion that is substantially bent at a right angle. 
     The operation unit includes a substantially shaft-shaped operation unit body (body portion), and an operating slider (sliding portion) that is slidable in an axis direction with respect to the operation unit body. A rotor provided at a base end of the sheath is rotatably connected to the operation unit body. 
     The operating wire can be advanced and retracted in the axis direction in an inner hole of the sheath by the sliding operation of the operating slider in the axis direction, and the knife unit can be protruded and retracted from the distal end portion of the sheath by the advance/retraction operation of the operating wire. The rotation of the knife unit can be suppressed by the contact pressure generated when the stopper receiving portion contacts to the stopper member. 
     When it is desired to change the orientation of the bent portion around the axis during treatment, the operating slider is slightly moved rearward (pulled back) with respect to the operation unit body, and the stopper receiving portion is separated from the stopper member. If the sheath is gripped and the operation unit is rotated around the axis, the knife unit rotates simultaneously around the axis, and the orientation of the bent portion changes. When the bent portion has the desired orientation, the operating slider is moved forward (pushed) with respect to the operation unit body, and the stopper receiving portion is pressed against the stopper member. At this time, even if an external force is applied to the knife unit, the orientation of the bent portion is not changed by the aforementioned contact pressure. 
     However, in the high-frequency knife, a state where the stopper receiving portion is pressed against the stopper member, that is, the operating slider is pushed, should be maintained in order for the orientation of the knife unit not to change. 
     A high-frequency knife is described also in the specification of United States Patent Application, Publication No. 2008-0306334. The high-frequency knife described in the specification of United States Patent Application, Publication No. 2008-0306334 is different from the high-frequency knife described in the aforementioned Japanese Patent No. 3923022 in that a linear member inserted through the sheath has a structure in which an energizing wire is inserted into a coiled sheath, and a ratchet mechanism is provided. 
     The coiled sheath is a member having higher rigidity when being compressed. 
     The aforementioned ratchet mechanism is provided at the operation unit, and limits pull-back of the operating slider. The ratchet mechanism has a plurality of teeth provided at the operation unit body closer to a tip side than the operating slider, and a claw pivoted at the tip of the operating slider by a pin and biased by a spring in a direction in which the claw meshes with the teeth. When the ratchet mechanism is released to pull back the operating slider, the engagement between the claw and the teeth is released by pushing a button at a base end of the claw so as to be brought close to the axis of the sheath. 
     In the high-frequency knife configured in this way, if the operating slider is pushed with respect to the operation unit body, the linear member is compressed and the coiled sheath becomes rigid. Since the ratchet mechanism is provided, it is not necessary to continue holding the operating slider in order to maintain the compressed state of the linear member, and the operating slider can be released from the hand. When the knife unit is made to protrude from the tip of the sheath, is moved, and performs incision, the coiled sheath becomes rigid, deflection can be prevented, and a sufficient amount of incision with respect to a traveling distance can be performed. 
     SUMMARY OF THE INVENTION  
     A medical treatment instrument of a first aspect of the present invention includes a sheath; an operating member which is advanced and retracted, and inserted into the sheath; a treatment unit which is provided at a distal end portion of the operating member; and an operation unit which has a body portion connected to a proximal end portion of the sheath and which causes the operating member to be advanced and retracted with respect to the sheath and to be rotated around a longitudinal axis of the body portion. The operation unit includes a sliding portion which is provided so as to be capable of advancing and retracting with respect to the body portion and rotating around the longitudinal axis of the body portion and which is connected to a proximal end portion of the operating member; and a regulating portion which is switchable to a movable state where the regulating portion is capable of advancing, retracting, and rotating with respect to the body portion and a limited state where the advance, retraction, and rotation of the sliding portion with respect to the body portion is limited. The regulating portion includes a dial portion which is rotatable around an axis orthogonal to the longitudinal axis; and a shaft-shaped member which is screwed to the dial portion and is capable of advancing and retracting relative to the dial portion in a direction in which the shaft-shaped member comes close to and separates from the body portion. The movable state and the limited state are switched as the shaft-shaped member comes close to and separates from the body portion with the turning of the dial portion. 
     According to a second aspect of the present invention based on the above first aspect, the body portion may have a body-side finger-hooking portion, the sliding portion may have a sliding-side finger-hooking portion located further toward a tip side than the body-side finger-hooking portion, and the regulating portion may be provided further toward the tip side than the sliding-side finger-hooking portion. 
     According to a third aspect of the present invention based on the above second aspect, at least a portion of the dial portion may be exposed to an outside from an outer peripheral surface of the sliding portion. 
     According to a fourth aspect of the present invention based on the above third aspect, a hole that penetrates in a direction of the axis of the dial portion may be formed in one of the dial portion and the shaft-shaped member. A female thread may be formed in an inner peripheral surface of the hole. The shaft-shaped member may advance and retract in the direction of the axis with respect to the dial portion in response to the turning of the dial portion by a male thread to be screwed to the female thread being formed in an outer peripheral surface of the other of the dial portion and the shaft-shaped member. 
     According to a fifth aspect of the present invention based on the above third aspect, a plane parallel to an advance and retraction direction of the sliding portion for contacting to an end portion of the shaft-shaped member may be formed on the shaft-shaped member side of the body portion. 
     According to a sixth aspect of the present invention based on the above fourth aspect, the end portion of the body portion side of the shaft-shaped member may be provided with an elastic member that contact to the plane. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         FIG. 1  is a cross-sectional view of a side surface when a high-frequency knife of a first embodiment of the present invention is brought into a push state and a movable state. 
         FIG. 2  is a cross-sectional view of cutting line A 1 -A 1  in  FIG. 1 . 
         FIG. 3  is a plan view showing a state where an operation unit of the high-frequency knife is gripped. 
         FIG. 4  is a cross-sectional view of a side surface on a base end side when the high-frequency knife is brought into a limited state. 
         FIG. 5  is a cross-sectional view of cutting line A 2 -A 2  in  FIG. 4 . 
         FIG. 6  is a partially cutaway side view when the high-frequency knife is brought into a pull-back state. 
         FIG. 7  is a view illustrating a procedure using the high-frequency knife, and is a view showing a state when a hole is made in a portion of a mucous membrane. 
         FIG. 8  is a view illustrating the procedure using the high-frequency knife, and is a view showing a state where a larger-diameter portion is inserted into the hole of the mucous membrane. 
         FIG. 9  is a view illustrating the procedure using the high-frequency knife, and is a view showing a state where the high-frequency knife is moved in a transverse direction to perform incision. 
         FIG. 10  is a perspective view illustrating the procedure using the high-frequency knife, and illustrating the operation of adjusting the orientation of a bent portion of a knife unit. 
         FIG. 11  is a perspective view illustrating the procedure using the high-frequency knife, and illustrating the operation of hooking the bent portion of the knife unit to an opening obtained by incising the periphery of a lesioned mucous membrane portion, and dissecting a submucosal layer of the lesioned mucous membrane portion. 
         FIG. 12  is a plan view on the base end side when a high-frequency knife in a modification example of the first embodiment of the present invention is brought into a movable state. 
         FIG. 13  is a plan view on the base end side when the high-frequency knife is brought into a limited state. 
         FIG. 14  is a cross-sectional view of a side surface on a base end side when a high-frequency knife of a second embodiment of the present invention is brought into a limited state. 
         FIG. 15  is a cross-sectional view of the side surface on the base end side when the high-frequency knife is brought into a movable state. 
         FIG. 16  is a partially cutaway side view when the high-frequency knife is brought into a push state. 
         FIG. 17  is a partially cutaway side view when the high-frequency knife is brought into a pull-back state. 
         FIG. 18  is a cross-sectional view of a side surface on a base end side when a high-frequency knife of a third embodiment of the present invention is brought into a limited state. 
         FIG. 19  is a cross-sectional view of the side surface on the base end side when the high-frequency knife is brought into a movable state. 
         FIG. 20  is a side view on the base end side when the high-frequency knife is brought into the movable state. 
         FIG. 21  is a cross-sectional view of a side surface when a high-frequency knife of a fourth embodiment of the present invention is brought into a pull-back state and a movable state. 
         FIG. 22  is a cross-sectional view of the side surface on a tip side when the high-frequency knife is brought into a push state. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     First Embodiment 
     Hereinafter, a first embodiment of a medical treatment instrument related to the present invention will be described referring to  FIGS. 1 to 13 , taking a case where the medical treatment instrument is a high-frequency knife as an example. 
     As shown in  FIGS. 1 and 2 , a high-frequency knife  1  of the present embodiment includes a sheath  10  having flexibility such that the sheath is insertable through a channel of an endoscope (not shown), an operating wire (operating member)  20  retractably inserted through the sheath  10 , a knife unit (treatment unit)  30  provided at a distal end portion of the operating wire  20 , and an operation unit  40  provided at a proximal end portion of the sheath  10 . 
     The sheath  10  is formed in a tubular shape, and a proximal end portion of the sheath  10  is provided with a rotor  10   a  configured to have a larger diameter than that on a tip side. The sheath  10  is formed from a material having insulation, such as a tetrafluoroethylene material. A distal end portion of the sheath  10  is provided with a tubular stopper member  11 , and an outer periphery of the stopper member  11  is covered with the distal end portion of the sheath  10 . A tapered portion  11   a  configured to have a smaller internal diameter towards the tip side, and a smaller-diameter hole  11   b  located on the tip side of the tapered portion  11   a  is formed in an inner surface of the stopper member  11 . 
     A ring-shaped sheath-tip insulating tip  12  that centers the knife unit  30  is disposed further toward the tip side than the stopper member  11 . An outer peripheral side of the sheath-tip insulating tip  12  is covered with the sheath  10 . The distal end portion of the sheath  10  is provided to extend to the tip side over the distal end portion of the sheath-tip insulating tip  12 . An accommodating portion  10   b , which is an internal space of the distal end portion of the sheath  10  and accommodates a bent portion  32  of the knife unit  30  to be described below, is formed further toward the tip side than the sheath-tip insulating tip  12 . 
     The knife unit  30  has a rod-shaped electrode portion  31  arranged on an axis C 1  of the sheath  10 , and a bent portion  32  that is provided at a distal end portion of the electrode portion  31  and extends in a direction substantially orthogonal to the axis C 1 . 
     The external diameter of the electrode portion  31  is set so that the electrode portion  31  is insertable through the smaller-diameter hole  11   b  of the stopper member  11  and a conduit line of the sheath-tip insulating tip  12 . The electrode portion  31  and the bent portion  32  are integrally formed from a conductive material, such as metal. 
     A proximal end portion of the electrode portion  31  and a distal end portion of the operating wire  20  are connected together by a stopper receiving portion  33  formed in a tubular shape from a conductive material. The external diameter of the stopper receiving portion  33  is set to be greater than the internal diameter of the smaller-diameter hole  11   b  of the stopper member  11 , and when the stopper receiving portion  33  moves to the tip side, the stopper receiving portion  33  abuts against the stopper member  11 . 
     The operation unit  40  has a body portion  41  provided at the proximal end portion of the sheath  10 , a sliding portion  42  made movable in a direction of the axis C 1  with respect to the body portion  41 , and a regulating portion  43  that limits that the sliding portion  42  moves in the direction of the axis C 1  with respect to the body portion  41 . 
     In the present embodiment, the body portion  41  is formed in the shape of a rod that extends in the direction of the axis C 1 . 
     A guide groove  41   a  is formed along the axis C 1  in the body portion  41 , and a body-side finger-hooking portion  46  is provided at the proximal end portion. A body-side through-hole  46   a  that is formed on the axis C 1  and penetrates in an orthogonal direction D orthogonal to the axis C 1  (refer to  FIG. 2 ) is formed in the body-side finger-hooking portion  46 . The size of the body-side through-hole  46   a  is set to a size such that the thumb of an operator, such as a surgeon, is insertable the through-hole. 
     A planar portion (plane)  41   b  parallel to an axis C 1  is formed in an outer surface of the body portion  41  on the tip side. An engaging portion  41   c  that engages the rotor  10   a  of the sheath  10  is formed in a tip of the body portion  41 . As the rotor  10   a  engages the engaging portion  41   c , the operation unit  40  can be rotated around an axis C 1  with respect to the sheath  10 . 
     The sliding portion  42  is provided with a first sliding-side finger-hooking portion (sliding-side finger-hooking portion)  47  and a second sliding-side finger-hooking portion  48  that are arranged side and side in the direction orthogonal to the axis C 1  in a side view. A first sliding-side through-hole  47   a  that penetrates in the orthogonal direction D is formed in the first sliding-side finger-hooking portion  47 . A second sliding-side through-hole (through-hole)  48   a  that penetrates in the orthogonal direction D is formed in the second sliding-side finger-hooking portion  48 . The finger-hooking portions  47  and  48  are symmetrical across the axis C 1 , and are arranged further toward the tip side than the body-side finger-hooking portion  46  in the direction of the axis C 1 . The through-holes  47   a  and  48   a  are formed with sizes such that operator&#39;s index finger and middle finger are insertable therethrough. 
     A connecting connector portion  49  is provided so as to protrude from the second sliding-side finger-hooking portion  48  side in the sliding portion  42 . A proximal end portion of the operating wire  20  is fixed to the connecting connector portion  49 . This allows the knife unit  30  to be electrically connected to the connecting connector portion  49  via the stopper receiving portion  33  and the operating wire  20 . A cord that leads to a high-frequency generator (not shown) is electrically connected to the connecting connector portion  49 . 
     The sliding portion  42  is attached to the body portion  41  so as to be movable in the direction of the axis C 1  along the guide groove  41   a  of the body portion  41 . 
     The regulating portion  43  has a dial portion  52  provided further toward the tip side than the first sliding-side finger-hooking portion  47  in the sliding portion  42 , and a movable body (shaft-shaped member)  53  to be screwed to the dial portion  52 . 
     The dial portion  52  is formed in the shape of a disk in a plan view, and is rotatably supported around an axis C 2  orthogonal to the axis C 1  of the sheath  10  within the accommodating portion  42   a  formed on the planar portion  41   b  side in the sliding portion  42 . A through-hole (hole)  52   a  that penetrates in the direction (the thickness direction) of the axis C 2  of the dial portion  52  is formed in the dial portion  52 . A female thread  52   b  is formed in an inner peripheral surface of the through-hole  52   a . In the present embodiment, as a step portion  52   c  formed at a bottom surface of the dial portion  52  engages a protrusion  42   b  provided on a bottom surface of the accommodating portion  42   a , the dial portion  52  is rotatably supported within the accommodating portion  42   a.    
     A portion  52   d , which is the edge of the dial portion  52  of which a tangential line T becomes parallel to the axis C 1 , is exposed to the outside from the sliding portion  42  (refer to  FIGS. 2 and 3 ). 
     A male thread  53   a  to be screwed to the female thread  52   b  of the dial portion  52  is formed in an outer peripheral surface of the movable body  53 . In addition, the female thread  52   b  and the male thread  53   a  are formed as so-called left-handed threads of which the orientation of helixes are left-handed. 
     The movable body  53  is arranged on the axis C 2 . The end portion of the movable body  53  opposite to the body portion  41  is inserted through and supported by a communication hole formed in the sliding portion  42 . The end portion of the movable body  53  on the body portion  41  side is provided with a pressing member (elastic member)  54  formed from a material elasticity, such as rubber. The pressing member  54  is formed, for example, in a columnar shape. The pressing member  54  is arranged so that its own bottom surface faces the planar portion  41   b  of the body portion  41  within a communication hole  42   c  formed in the bottom surface of the accommodating portion  42   a.    
     As the regulating portion  43  configured in this way turns the dial portion  52  around the axis C 2 , the movable body  53  is brought close to and separated from the planar portion  41   b  of the body portion  41  by the screwing between the female thread  52   b  and the male thread  53   a.    
     In  FIGS. 1 and 2 , the planar portion  41   b  of the body portion  41  and the pressing member  54  are separated from each other and the sliding portion  42  is movable in the direction of the axis C 1  with respect to the body portion  41 . 
     The high-frequency knife  1  configured in this way is a so-called flexible treatment tool in which the sheath  10  and the operating wire  20  are bendable. 
     When an operator grips the operation unit  40 , in order to effectively transmit the forces of fingertips to the body portion  41  and the sliding portion  42 , usually, as shown in  FIG. 3 , a thumb P 11  of a right hand P 10  is inserted through the body-side through-hole  46   a  of the body-side finger-hooking portion  46 , an index finger P 12  is inserted through the first sliding-side through-hole  47   a  of the first sliding-side finger-hooking portion  47 , and the middle finger P 13  is inserted through the second sliding-side through-hole  48   a  of the second sliding-side finger-hooking portion  48 . 
     Then, when the dial portion  52  is operated, the index finger P 12  is moved forward to move the portion  52   d  of the dial portion  52  to the tip side in a state where the index finger P 12  is taken out of the first sliding-side through-hole  47   a  and the position of the thumb P 11  the position of the middle finger P 13  are fixed. This turns the dial portion  52  as shown by arrow B 1  around an axis C 2 . Then, as shown in  FIGS. 4 and 5 , the movable body  53  moves so as to approach the planar portion  41   b  of the body portion  41 , and presses the pressing member  54  against the planar portion  41   b . Since the planar portion  41   b  is formed in a flat shape, the planar portion  41   b  and the pressing member  54  are brought into close contact with each other. Accordingly, the body portion  41  is not able to move in the direction of the axis C 1  with respect to the pressing member  54 , and is brought into a limited state where the movement of the sliding portion  42  in the direction of the axis C 1  with respect to the body portion  41  is limited. 
     The portion  52   d  of the dial portion  52  are moved to the base end side by the index finger P 12  to turn the dial portion  52  as indicated by arrow B 2  with a direction opposite to the direction of arrow B 1 . Accordingly, the movable body  53  is separated from the planar portion  41   b , and the regulating portion  43  is brought into a movable state. 
     In this way, by moving the portion  52   d  of the dial portion  52  to the tip side or the base end side to turn the dial portion  52  around an axis C 2 , the regulating portion  43  can be switched between the limited state and the movable state. 
     Additionally, when the regulating portion  43  is in the movable state, the sliding portion  42  is moved to (pushed into) the tip side in the direction of the axis C 1  with respect to the body portion  41  as shown in  FIG. 1  by separating the index finger P 12  reinserted into the first sliding-side through-hole  47   a  and separating the middle finger P 13  from the thumb P 11 . Accordingly, the operating wire  20  moves to the tip side with respect to the sheath  10 , the stopper receiving portion  33  abuts against the stopper member  11 , and the knife unit  30  is positioned in a state where the knife unit  30  protrudes forward from the distal end portion of the sheath  10 . The rotation of the knife unit  30  around the axis C 1  with respect to the sheath  10  is limited by the contact pressure generated when the stopper receiving portion  33  abuts against the stopper member  11 . 
     On the other hand, if the sliding portion  42  is moved to (pulled back to) the base end side in the direction of the axis C 1  with respect to the body portion  41  as shown in  FIG. 6  by bringing the index finger P 12  and the middle finger P 13  close to the thumb P 11 , the bent portion  32  of the knife unit  30  abuts against a tip surface of the sheath-tip insulating tip  12 . At this time, the bent portion  32  of the knife unit  30  is accommodated in the accommodating portion  10   b  of the sheath  10 , and the knife unit  30  is positioned in the pull-back state in which the knife unit  30  is accommodated within the sheath  10 . 
     Next, the operation of the high-frequency knife  1  configured as mentioned above will be described. In the following, for example, the operation when excision of a mucous membrane within a body cavity is endoscopically performed using the high-frequency knife  1  will be described. 
     First, an injection needle (not shown) is introduced into the body cavity through an endoscope (not shown). Then, as shown in  FIG. 7 , a physiological salt solution is injected into a submucosal layer of a lesioned mucous membrane portion Q 1  that is a target part of the body cavity to be excised, and the lesioned mucous membrane portion Q 1  is caused to bulge. 
     Subsequently, the initial incision of endoscopically introducing a well-known high-frequency knife E 10  having a rod-shaped electrode E 11  provided at a tip thereof to make a hole Q 2  in a portion of the mucous membrane around the lesioned mucous membrane portion Q 1  is performed. 
     Subsequently, as shown in  FIG. 8 , a well-known high-frequency knife E 20  in which a larger-diameter portion E 21  formed from an insulating material is provided at a distal end portion of the electrode E 11  is similarly introduced into the body cavity via a channel of the endoscope. Then, the larger-diameter portion E 21  of the high-frequency knife E 20  is inserted into the hole Q 2  formed by the initial incision. In this state, while a high-frequency current is applied to an electrode E 11 , as shown in  FIG. 9 , the high-frequency knife E 20  is moved to incise the periphery of the lesioned mucous membrane portion Q 1 . 
     Then, after the entire circumference of the lesioned mucous membrane portion Q 1  is incised, the high-frequency knife  1  of the present embodiment is used. At this time, the high-frequency knife  1  is brought into the pull-back state where the knife unit  30  is accommodated within the sheath  10  in advance, and the regulating portion  43  is brought into the movable state. In this state, the operator grips the operation unit  40  with the right hand P 10  as mentioned above, and introduces the high-frequency knife  1  into the body cavity via the channel of the endoscope. Then, as shown in  FIG. 10 , the knife unit  30  is made to abut against an opening Q 3  formed by incising the periphery of the lesioned mucous membrane portion Q 1 , the bent portion  32  is hooked, and the submucosal layer of the lesioned mucous membrane portion Q 1  is dissected. At this time, it is desirable that the bent portion  32  of the knife unit  30  be parallel to an intrinsic muscle layer or be directed to an inner cavity side. 
     Additionally, when the bent portion  32  is not directed to desirable orientation, the orientation of the bent portion  32  is adjusted by a method as shown in  FIG. 11 . Specifically, the sheath  10  is gripped with the left hand P 20  and the operation unit  40  is rotated, in a state where the sliding portion  42  is slightly pulled back. Subsequently, the sliding portion  42  is pushed and brought into the push state by pushing out the index finger P 12  and the middle finger P 13  inserted through the through-holes  47   a  and  48   a  forward with respect to the thumb P 11  of the right hand P 10  inserted through the body-side through-hole  46   a  after the orientation of the bent portion  32  is changed. The rotation of the knife unit  30  around the axis C 1  is limited by the contact pressure generated when the stopper receiving portion  33  abuts against the stopper member  11 . 
     As shown in  FIG. 3 , the index finger P 12  is taken out of the first sliding-side through-hole  47   a  in a state where the middle finger P 13  is pushed out forward with respect to the thumb P 11 . By moving the index finger P 12  forward to move the portion  52   d  of the dial portion  52  to the tip side, the dial portion  52  is turned as shown by arrow B 1 . Accordingly, as shown in  FIGS. 4 and 5 , the pressing member  54  abuts against the planar portion  41   b , and the regulating portion  43  is brought into the limited state. 
     Accordingly, the knife unit  30  is fixed to the sheath  10  and also the endoscope in a state where the bent portion  32  maintains desired orientation. Since the orientation of the bent portion  32  is fixed, mucous membrane incision can be safely performed. 
     A high-frequency current is supplied to the knife unit  30  by connecting the cord of the high-frequency generator to the connecting connector portion  49 , and the incision (treatment) of the submucosal layer of the lesioned mucous membrane portion Q 1  is continued. 
     Then, after all the lesioned mucous membrane portion Q 1  is excised, the lesioned mucous membrane portion Q 1  is gripped by gripping forceps (not shown), is endoscopically taken out to the outside of a patient&#39;s body, and the treatment is ended. 
     As described above, according to the high-frequency knife  1  of the present embodiment, the regulating portion  43  is switched to the movable state by moving the portion  52   d  of the dial portion  52  to the base end side in the direction of the axis C 1  with the index finger P 12  when being in the limited state when the movement of the sliding portion  42  in the direction of the axis C 1  with respect to the body portion  41  is limited. Similarly, the regulating portion  43  is switched to the limited state by moving the portion  52   d  of the dial portion  52  to the tip side in the direction of the axis C 1  with the index finger P 12  when the regulating portion  43  is in the movable state. 
     Since the direction of the axis C 1  in which the sliding portion  42  is moved with respect to the body portion  41 , and the direction in which the portion  52   d  of the dial portion  52  when switching is performed between the movable state and the limited state is moved are parallel to each other, the operation caused by the index finger P 12  that switches the regulating portion  43  between the movable state and the limited state can be easily performed. 
     Both the orientation in which the middle finger P 13  is pushed out when the stopper receiving portion  33  is pressed against the stopper member  11  and the orientation in which the portion  52   d  of the dial portion  52  is moved when the regulating portion  43  is switched from the movable state to the limited state are the same as the front. Accordingly, the index finger P 12  is easily powered during the operation of the dial portion  52 , and the operation of the dial portion  52  by the index finger P 12  can be easily performed. 
     Since the portion  52   d  of the dial portion  52  of the regulating portion  43  is exposed to the outside, the portion  52   d  can be easily operated with the index finger P 12 . 
     The regulating portion  43  has the dial portion  52  and the movable body  53 . Accordingly, a mechanism in which the movable body  53  is brought close to and separated from the planar portion  41   b  by turning the dial portion  52  can be easily and cheaply configured. 
     The planar portion  41   b  is formed in the body portion  41 . For this reason, the body portion  41  and the pressing member  54  can be brought into close contact with each other, and the movement of the sliding portion  42  in the direction of the axis C 1  with respect to the body portion  41  can be reliably limited. 
     The end portion of the movable body  53  on the body portion  41  side is provided with the pressing member  54 . Accordingly, the body portion  41  and the movable body  53  can be reliably brought into contact with each other via the pressing member  54 , and the movement of the sliding portion  42  can be more reliably limited. 
     In the present embodiment, the turning angle of the dial portion  52  required when switching is performed between the movable state and the limited state can be made small by making the gap between the planar portion  41   b  of the body portion  41  and the pressing member  54  in the movable state small or by enlarging the pitch of the female thread  52   b  of the dial portion  52  and the male thread  53   a  of the movable body  53 . 
     For example, in a high-frequency knife  2  of the modification example of the present embodiment shown in  FIG. 12 , the dial portion  52  is provided with a knob  57  that protrudes radially outward. In this case, a portion  57   a  of the knob  57  serving as a distal end portion in a protruding direction is an edge of the dial portion  52 , and a tangential line T of this edge is a portion that is parallel to the axis C 1 . 
     The index finger P 12  is hooked to the portion  57   a  of the knob  57  when the regulating portion  43  shown in  FIG. 12  is in the movable state. By moving the index finger P 12  to the tip side as shown in  FIG. 13 , the dial portion  52  is turned around the axis C 2  as shown by arrow B 1 . In this example, switching is performed from the movable state to the limited state by turning the dial portion  52  by about 90 degrees around the axis C 2 . 
     In the high-frequency knife  2  of the modification example configured in this way, the turning angle of the dial portion  52  required when switching is performed between the movable state and the limited state can be made small to such a degree that operation is not hindered. Additionally, by providing the dial portion  52  with the knob  57 , a force required to turn the dial portion  52  can be reduced. 
     In the present embodiment, when a frictional force generated when the movable body  53  is pressed against the body portion  41  is relatively great, the planar portion  41   b  may not be formed at the body portion  41 . Additionally, the pressing member  54  may not be provided at the movable body  53 . 
     Although the dial portion  52  is formed in the shape of a disk in a plan view, the shape of the dial portion  52  is not limited to this. For example, by discretely forming a slip-preventing groove portion in a circumferential direction at the edge of the dial portion, the dial portion may be formed in a polygonal shape, such as a hexagonal shape, in the shape of a star, or the like in a plan view. 
     In the present embodiment, the through-hole  52   a  is formed in the dial portion  52 , the female thread  52   b  is formed in the inner peripheral surface of the through-hole  52   a , and the male thread  53   a  to be screwed to the female thread  52   b  of the dial portion  52  is formed in the outer peripheral surface of the movable body  53 . However, the through-hole may be formed in the axis direction of the movable body, the female thread is formed in the inner peripheral surface of the through hole, and the male thread to be screwed to the female thread of the movable body may be formed in the outer peripheral surface of the dial portion. 
     Even if the present invention is configured in this way, the same effects as the present embodiment can be exhibited. 
     Second Embodiment 
     Next, although a second embodiment of the present invention will be described referring to  FIGS. 14 to 17 , the same parts as the above embodiment will be designated by the same reference numerals and the description thereof will be omitted, and only different points will be described. 
     As shown in  FIG. 14 , a high-frequency knife  3  of the present embodiment includes a regulating portion  61  having a ratchet portion  62 , instead of the regulating portion  43  in the high-frequency knife  1  of the first embodiment. 
     The ratchet portion  62  has a plurality of body-side claw portions  63  provided instead of the planar portion  41   b  in the body portion  41 , and a sliding-side claw portion  64  that are rotatably supported by the sliding portion  42 . 
     The plurality of body-side claw portions  63  are arranged side by side along the axis C 1  on a side surface of the body portion  41 . The respective body-side claw portions  63  are formed in a substantially triangular shape in a side view. The body-side claw portions  63  are formed so that the surfaces thereof on the tip side are orthogonal to the axis C 1  and so that the surfaces thereof on the base end side approach the axis C 1  towards the base end side. 
     An accommodating portion  67  is formed in a portion between the first sliding-side finger-hooking portion  47  in the sliding portion  42  and the axis C 1 . The accommodating portion  67  communicates with an opening  47   b  formed in the inner peripheral surface of the first sliding-side through-hole  47   a  on the base end side, and an opening  42   d  formed in the sliding portion  42  so as to face the body-side claw portions  63 , respectively. 
     The sliding-side claw portion  64  is fixed to one arm portion  68   a  of a torsion spring  68  in a state where the portion thereof is disposed within the accommodating portion  67 . Another arm portion  68   b  of the torsion spring  68  is fixed to the sliding portion  42 . A button (a portion of the regulating portion  61 )  64   a  is provided near the distal end portion of sliding-side claw portion  64  in an extending direction in which one arm portion  68   a  extends. The button  64   a  is provided in a state where the button is exposed to the base end side within the first sliding-side through-hole  47   a . The end portion of the sliding-side claw portion  64  opposite to the button  64   a  is provided with a claw  64   b  engageable with the body-side claw portions  63 . 
     In the high-frequency knife  3  configured in this way, the body-side claw portions  63  are engaged with the claw  64   b  as the arm portion  68   a  is turned around a connecting portion  68   c  between the arm portion  68   a  and the arm portion  68   b  by the biasing force of the torsion spring  68 . At this time, a state where the movement (pull-back) of the sliding portion  42  to the base end side with respect to the body portion  41  is limited by the engagement between body-side claw portions  63  and the claw  64   b  is a limited state. It should be noted that, even in this limited state, the sliding portion  42  can be moved (pushed) to the tip side with respect to the body portion  41 . 
     Meanwhile, if the operator inserts the index finger P 12  or the like into the first sliding-side through-hole  47   a  and moves the button  64   a  on the base end side as shown in  FIG. 15  with the inserted index finger P 12 , the sliding-side claw portion  64  is turned around the connecting portion  68   c , and the engagement between the body-side claw portions  63  and the claw  64   b  is released. Accordingly, the sliding portion  42  can be switched to the movable state where the sliding portion is movable both to the tip side and to the base end side with respect to the body portion  41 . 
     When mucous membrane incision within the body cavity is performed using the high-frequency knife  3  configured in this way, as shown in  FIG. 16 , the sliding portion  42  is pushed and brought into the push state by pushing out the index finger P 12  and the middle finger P 13  inserted through the through-hole  47   a  and the through-hole  48   a  forward with respect to the thumb P 11  of the right hand P 10  inserted through the body-side through-hole  46   a . At this time, since the index finger P 12  biases the first sliding-side finger-hooking portion  47  so as to be pushed out forward within the first sliding-side through-hole  47   a , the index finger P 12  is in a state where the index finger comes in contact with the inner peripheral surface of the first sliding-side through-hole  47   a  on the tip side and does not come in contact with the button  64   a.    
     The stopper receiving portion  33  abuts against the stopper member  11 , the contact pressure acts on the stopper member, and the rotation of the knife unit  30  around an axis C 1  with respect to the sheath  10  is limited. 
     If the forward push-out by the index finger P 12  and the middle finger P 13  is stopped, the sliding portion  42  is pushed back to the base end side via the stopper receiving portion  33  and the operating wire  20  by the reaction force of the stopper member  11 . However, since the regulating portion  61  is in the limited state, the sliding portion  42  is not pulled back to the base end side, and a state where the rotation of the knife unit  30  is limited is maintained. 
     When the sliding portion  42  is pulled back and brought into the pulled-back state where the knife unit  30  is accommodated within the sheath  10 , as shown in  FIG. 17 , the index finger P 12  inserted through the first sliding-side through-hole  47   a  is moved to the base end side. Accordingly, the button  64   a  biased to the index finger P 12  moves to the base end side, the engagement between body-side claw portions  63  and the claw  64   b  are released, and the regulating portion  61  is switched to the movable state. Accordingly, the sliding portion  42  can be pulled back. 
     As described above, according to the high-frequency knife  3  of the present embodiment, switching is performed from the limited state to the movable state simply by moving the button  64   a  to the base end side, and if the button  64   a  is returned to its original position, switching is performed from the movable state to the limited state. For this reason, the switching between the movable state and the limited state can be easily performed. 
     Third Embodiment 
     Next, although a third embodiment of the present invention will be described referring to  FIGS. 18 to 20 , the same parts as the above embodiment will be designated by the same reference numerals and the description thereof will be omitted, and only different points will be described. 
     As shown in  FIG. 18 , a high-frequency knife  4  of the present embodiment includes a sliding-side claw portion  71  instead of the sliding-side claw portion  64  in the high-frequency knife  3  of the second embodiment. 
     In the present embodiment, the first sliding-side finger-hooking portion  47  is provided on the connecting connector portion  49  side in the sliding portion  42 . The second sliding-side finger-hooking portion  72  is provided opposite to the first sliding-side finger-hooking portion  47  with respect to the axis C 1  in the sliding portion  42 . In this example, a finger-hooking recess  72   a  formed in a shape that is recessed toward the tip side in a side view is formed in the second sliding-side finger-hooking portion  72 . 
     An intermediate portion of the aforementioned sliding-side claw portion  71  in the longitudinal direction is rotatably supported by a pin  74  provided on the sliding portion  42  further toward the tip side than the second sliding-side finger-hooking portion  72 . A distal end portion of the sliding-side claw portion  71  is provided with a claw  71   a  that is engageable with the body-side claw portions  63  formed at the body portion  41 . A torsion spring  77  is attached between the sliding-side claw portion  71  and the sliding portion  42 , and the torsion spring  77  is biased so that the claw  71   a  engages the body-side claw portions  63 . A cover  75  formed from a material having elasticity, such as rubber, is attached to the portion of the sliding-side claw portion  71  from an intermediate portion to a proximal end portion. 
     In addition, the plurality of body-side claw portions  63  and the sliding-side claw portion  71  constitute the regulating portion  76 . 
     The high-frequency knife  4  configured in this way is brought into the limited state where the claw  71   a  is engaged with the body-side claw portions  63  similar to the second embodiment and the pull-back of the sliding portion  42  with respect to the body portion  41  is limited, in a state where the operator does not operate the sliding-side claw portion  71 . It should be noted that, even in this limited state, the sliding portion  42  can be pushed and brought into the push state by pushing out the index finger P 12  pressed against the finger-hooking recess  72   a  and the middle finger P 13  inserted through the first sliding-side through-hole  47   a  forward with respect to the thumb P 11  inserted through the body-side through-hole  46   a.    
     On the other hand, when the sliding portion  42  is pulled back, as shown in  FIGS. 19 and 20 , the index finger P 12  is separated from the finger-hooking recess  72   a , the proximal end portion of the cover  75  is moved to the base end side with the index finger P 12 , and the engagement between the body-side claw portions  63  and the claw  71   a  is released against the biasing force of the torsion spring  77 . 
     As described above, according to the high-frequency knife  4  of the present embodiment, the switching between the movable state and the limited state can be easily performed. 
     Additionally, by providing the sliding-side claw portion  71  in a place apart from the finger-hooking recess  72   a  that presses the index finger P 12  when the sliding portion  42  is pushed, the sliding-side claw portion  71  can be kept from being unintentionally operated. 
     Fourth Embodiment 
     Next, although a fourth embodiment of the present invention will be described referring to  FIGS. 21 and 22 , the same parts as the above embodiment will be designated by the same reference numerals and the description thereof will be omitted, and only different points will be described. In the present embodiment, a case where the medical treatment instrument is a grip operating device will be described. 
     As shown in  FIG. 21 , the grip operating device  5  of the present embodiment includes a sheath  80  having flexibility, the operating wire  20  retractably inserted through the sheath  80 , forceps (treatment unit)  90  provided at the distal end portion of the operating wire  20 , and the aforementioned operation unit  40  provided at a proximal end portion of the sheath  80 . 
     In the present embodiment, the sheath  80  is formed from, for example, a closely wound coil. 
     A hollow tubular body  81  is attached to a distal end portion of the sheath  80 . The forceps  90  has a pair of forceps pieces  91  and  92 , proximal end portions of the forceps pieces  91  and  92  are fixed to the distal end portion of the operating wire  20 , and distal end portions of the forceps pieces  91  and  92  are configured so as to be separated for each other in a natural state where an external force does not act. 
     The proximal end portion of the operating wire  20  is fixed to the body portion  41 . Meanwhile, the proximal end portion of the sheath  80  is fixed to the sliding portion  42 . 
     The sheath  80  is inserted through a sheathing tube  101 . A proximal end portion of the sheathing tube  101  is attached to a body outer tube  102  disposed so as to surround that the body portion  41 . 
     In the grip operating device  5  configured in this way, the tubular body  81  is arranged further toward the base end side than the forceps  90  in the pull-back state where the sliding portion  42  is pulled back shown in  FIG. 21 , and thus, the forceps pieces  91  and  92  are brought into an open state. A tissue Q 6  is pressed between the forceps pieces  91  and  92  in the open state, and fingers are hooked to the finger-hooking portions  46 ,  47 , and  48  to push-in the sliding portion  42  and bring the sliding portion into the push state. Then, as shown in  FIG. 22 , the forceps pieces  91  and  92  are pulled into a tube hole of the tubular body  81  and are closed as the tubular body  81  moves to the tip side with respect to the forceps  90 . At this time, the tissue Q 6  is pinched and gripped between the forceps pieces  91  and  92 . 
     Generally, in the endoscopic submucosal dissection (ESD), incision is performed using a high-frequency knife or the like in a state where a tissue is gripped by a grip operating device or the like. In the grip operating device  5  of the present embodiment, a state where the forceps pieces  91  and  92  are closed is maintained when the sliding portion  42  is pushed and brought into the push state. Therefore, the forceps pieces  91  and  92  do not open unintentionally. 
     Although the first to fourth embodiments of the present invention have been described above in detail with reference to the drawings, specific configuration is not limited to the embodiments, and changes of the configuration are also included without departing from the scope of the present invention. Moreover, it is obvious that the respective configurations shown in the respective embodiments may be combined and used appropriately. 
     For example, if one finger-hooking portion (first sliding-side finger-hooking portion  47 ) is formed in the sliding portion  42 , it is possible to hook a finger to the finger-hooking portion and move the sliding portion  42 . Therefore, in the above first, second, and fourth embodiments, the operation unit may not be provided with the second sliding-side finger-hooking portion  48 . 
     In the first to fourth embodiments, the female thread  52   b  and the male thread  53   a  of the operation unit  40  are formed as left-handed threads. However, when a left-handed operator uses the present invention, it is preferable to form the female thread  52   b  and the male thread  53   a  as so-called right-handed threads. 
     Although the sheath is formed from a material having flexibility, the sheath may be formed from a hard material, such as stainless steel. In this case, a high-frequency knife, which is a so-called rigid treatment tool, can be inserted through a channel of a hard mirror in which an insertion section does not bend, and can be used. 
     The operation unit having the body portion  41 , the sliding portion  42 , and the regulating portion in the medical treatment instrument of the present invention, is not limited to medical applications, but also can be preferably used for various kinds of experiments and research, as an operation unit for operating a robot, or the like. 
     Although the preferred examples of the present invention have been described above, the present invention is not limited to these examples. Additions, omissions, substitutions, and other modifications of components can be made without departing from the concept of the present invention. The present invention is not to be considered as being limited by the foregoing description, and is limited only by the scope of the appended claims.