Patent Publication Number: US-2021186546-A1

Title: Treatment device

Description:
This application is a continuation application of a PCT International Application No. PCT/JP2019/041596, filed on Oct. 24, 2019, whose priority is claimed on a US Provisional Application No. 62/749,877, filed on Oct. 24, 2018. The contents of the PCT International Application and the US provisional Application are incorporated herein by reference. 
    
    
     BACKGROUND 
     Conventionally, treatment devices (endoscopic treatment devices) are used. The treatment device is connected by a wire, and the treatment device has biopsy forceps protruding from a sheath through the wire is inserted and a treatment mechanism such as grasping forceps, endoscopic clip, and the like. The treatment device reaches the treatment target site through an endoscope channel. The treatment mechanism is configured to operate by moving the wire with respect to the sheath so as to perform the treatment. 
     The endoscopic treatment device disclosed in Japanese Patent No. 3370601 is configured in consideration of that a substantial length of the sheath changes due to a bending degree when being used and a necessary operation stroke for operating the endoscope treatment device changes. In the endoscopic treatment device disclosed in Japanese Patent No. 3370601, a stopper is provided to restrict a range by which a slider (second finger hook) is able to relatively move with respect to the sheath, wherein the slider is connected to the wire to stroke the wire. According to the endoscopic treatment device disclosed in Japanese Patent No. 3370601, the necessary proper stroke amount is reproduced due to the stopper. 
     In a case in which the endoscopic clip reaches the treatment target site, when the endoscopic clip is moved in the endoscope channel while the arms are in an open state, distal ends of the arms may come in contact with the endoscope channel and damage the endoscope channel. The arms of the endoscopic clip are biased toward the distal end side. Accordingly, in order to prevent the damage to the endoscope channel, it is necessary for the user to operate the endoscopic clip to reach the treatment target site while pulling the slider to resist the biasing force and thus keep a state in which the arms are accommodated in a pipe provided at the distal end of the sheath. 
     In the case of making the biopsy forceps and the grasping forceps to reach the treatment target site, when the cup and the grasper are advanced in the endoscope channel in a state of exposing from the pipe provided at the distal end of the sheath, distal ends of the cup and the grasper may come in contact with the endoscope channel and damage the endoscope channel. In order to prevent damage to the endoscope channel, it is necessary for the user to make the biopsy forceps reach the treatment target site while pulling the slider so as to maintain the state in which the cups and the graspers are accommodated in the pipe. 
     Generally, it is difficult for the user to make the treatment device reach the treatment target site while pulling the slider. In the case of dealing with the endoscopic clip, at the time of making the endoscopic clip reach the treatment target site while pulling the slider, the endoscopic clip may be incorrectly locked if the force for pulling the slider is too strong. 
     SUMMARY 
     The present disclosure relates to a treatment device. 
     One aspect of the present disclosure provides a treatment device including an arm member having a plurality of arms and configured to have an open state and a closed state; a wire having a distal end connected to the arm member, wherein the distal end of the wire is attachable and detachable to the arm member; a sheath through which the wire is inserted; an operator connected to a proximal end of the sheath; a slider connected to the wire and attached to the operator so as to be slidable toward a distal end or a proximal end of the operator, wherein the slider is configured to make the plurality of arms to be in the closed state when the slider is disposed in a first range, and the slider is configured to make the plurality of arms to be in the open state when the slider is disposed in a second range; and a slider restriction mechanism provided between the distal end of the operator and the slider, wherein when the slider is disposed in the first range, the slider restriction mechanism is configured to restrict an operational range of the slider in the first range, and when a user applies a force to move the slider from the first range to the second range, the slider restriction mechanism is configured to transfer a first state in which the operational the slider is restricted in the first range to a second state in which the operational range of the slider includes the first range and the second range. 
     In other aspects, the treatment device may further include a pipe provided at a distal end of the sheath, wherein the wire is inserted through the sheath, and the pipe is configured to accommodate the arm member, the arm member is configured to take a first position and a second position, the arm member is accommodated in the pipe at the first position, and the arm member is ejected from the distal end of the pipe at the second position, and the arm member is biased from the first position toward the second position. 
     In other aspects, in a situation when the slider restriction mechanism is in the second state and the arm member is at the second position, the arm member may be moved to the first position by moving the slider to the first range despite of a bending state of the sheath. 
     In further aspects, the slider restriction mechanism may include a first member and a second member that are movable along a sliding direction of the slider, the first member and the second member may configure a ratchet structure such that the first member and the second member are relatively movable only in a passing-by direction when the first member and the second member are engaged with each other. 
     In yet further aspects, the slider restriction mechanism may further have a spring having a resistance force against an advancement of the slider, in the first state, a bending degree of the sheath increase such that the sheath extends and the slider moves to the distal end side of the operator, while the slider restriction mechanism is reversibly contracted, and in the second state, the slider restriction mechanism is applied by a force from the distal end of the operator and the slider such that the slider restriction mechanism is irreversibly contracted. 
     In another aspect, the slider restriction mechanism may include a first member and a second member which are movable along the sliding direction of the slider, and the spring sandwiched by the first member and the second member, the first member and the second member may configure a ratchet structure such that the first member and the second member are relatively movable only in a passing-by direction when the first member and the second member are engaged with each other; the first member and the second member may not engage with each other in the first state, and the first member and the second member may engage with each other in the second state. 
     In another aspect, the slider restriction mechanism may be configured from a plurality of springs having different yield points, wherein the plurality of springs are continuously provided along the sliding direction of the slider 
     In another aspect, the treatment device may further include an elastic member provided at the pipe, wherein the elastic member has a force to bias the arm member to the second position. 
     In another aspect, the arm member may be a pair of forceps. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a cross-sectional view showing a treatment device according to a first exemplary embodiment and showing a state before the treatment device is used. 
         FIG. 2  is an enlarged cross-sectional view showing a circumference of an endoscopic clip according to the first embodiment and showing an open state of arm members. 
         FIG. 3  is a view showing the arms operated from the state shown in  FIG. 2  to a closed state. 
         FIG. 4  is a view showing the endoscopic clip separated from the state shown in  FIG. 3 . 
         FIG. 5  is a cross-sectional view of the treatment device shown in  FIG. 1  when a sheath is in a straight state and the arm members are in the open state. 
         FIG. 6  is a view showing an operation of moving a slider toward a proximal end side of an operation portion. 
         FIG. 7  is a cross-sectional view showing a treatment device according to a second exemplary embodiment and showing a state before the treatment device is used. 
         FIG. 8  is a view showing a state when a slider is moved toward a distal end side from the state shown in  FIG. 7 . 
         FIG. 9  is a view showing a state when the slider is moved in an operational range. 
         FIG. 10  is a view showing a state when the slider is moved in a standby range. 
         FIG. 11  is a cross-sectional view showing the treatment device shown in  FIG. 1  and showing a standby range when the sheath is in a bending state. 
         FIG. 12  is a cross-sectional view showing the treatment device shown in  FIG. 1  and showing an operational range when the sheath is in the bending state. 
         FIG. 13  is a cross-sectional view showing the treatment device shown in  FIG. 1  and showing a standby range when the sheath is in a once-wrapped state. 
         FIG. 14  is a cross-sectional view showing the treatment device shown in  FIG. 1  and showing an operational range when the sheath is in the once-wrapped state. 
         FIG. 15  is a perspective view showing a slider restriction mechanism of a treatment device according to a third exemplary embodiment. 
         FIG. 16  is a planar view showing the slider restriction mechanism in  FIG. 15 . 
         FIG. 17  is a cross-sectional view showing the treatment device according to the third embodiment and showing a state before the treatment device is used. 
         FIG. 18  is a cross-sectional view showing the treatment device in  FIG. 17  and showing an operational range when the sheath is in a straight state. 
         FIG. 19  is a cross-sectional view showing the treatment device in  FIG. 17  and showing the operational range when the sheath is in a bent state. 
         FIG. 20  is a cross-sectional view showing the treatment device in  FIG. 17  and showing the operational range when the sheath is in a once-wrapped state. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Hereinafter, an exemplary first embodiment of the present disclosure will be described by referring to  FIG. 1  to  FIG. 9 . 
     A treatment device  1  according to the present embodiment is a device configured to operate an endoscopic clip EC, for example, to pass through an endoscope channel to reach a treatment target site. 
       FIG. 1  is a cross-sectional view showing the treatment device  1  according to the present embodiment. As shown in  FIG. 1 , the treatment device  1  has an operation portion (operator)  2 , a slider  3 , a slider restriction mechanism  4 , a wire  5 , a sheath  6 , and the endoscopic clip EC. 
     The operation portion  2  is configured for a user to grasp the treatment device  1 . A finger hook portion (finger hook)  2   f  is formed, for example, as a hole having an elliptical shape at the side of the proximal end  2   p  in the operation portion  2 . The user inserts a thumb in the finger hook portion  2   f  to grasp the treatment device  1 . 
     The slider  3  is configured to move the endoscopic clip EC toward the proximal end side or the distal end side via the wire  5 . The slider  3  is attached to the operation portion  2  so as to be slidable between the proximal end  2   b  and the distal end  2   t  of the operation portion  2 . The user grasps the slider  3  by the forefinger and the middle finger for example and moves the slider  3  between the proximal end  2   p  and the distal end  2   t  of the operation portion  2  so as to move the endoscopic clip EC toward the proximal end side and the distal end side. 
     The slider restriction mechanism  4  is configured to restrict the movement of the slider  3  by resisting the bias toward the distal end side where the endoscopic clip is provided. The slider restriction mechanism  4  is provided between the distal end  2   t  and the proximal end  2   p  of the operation portion  2 , and the wire  5  is inserted through the slider restriction mechanism  4 . 
     The slider restriction mechanism  4  has a grasping portion (first member)  41  and a grasped portion (second member)  42 . Each of the grasping portion  41  and the grasped portion  42  has a hollow portion formed along an axial direction, and the wire  5  is inserted through the hollow portion. Each of the grasping portion  41  and the grasped portion  42  has an asymmetrical shape with respect to the axis. 
     The grasping portion  41  and the grasped portion  42  configure a ratchet mechanism. In a case in which the grasping portion  41  and the grasped portion  42  come in contact with each other and move in the passing-by direction (opposite direction) with respect to each other since the slider restriction mechanism  4  is contracted, it is possible that a protrusion  41 P of the grasping portion  41  and a protrusion  42 P of the grasped portion  42  get over each other and pass by each other. When the protrusion  41 P and the protrusion  42 P get over each other, since the protrusion  41 P and the protrusion  42 P engage with each other, the movement in the direction in which the protrusion  41 P and the protrusion  42 P separate from each other is prevented. According to the present embodiment, one protrusion  42 P of the grasped portion  42  is provided along the axial direction, a plurality of the protrusions  42 P may be provided. 
     The wire  5  is configured to move the endoscopic clip EC toward the distal end side in association with the stroke by the slider  3 . The wire  5  is configured to have a distal end attachably and detachably connected to the endoscopic clip EC and a proximal end connected to the slider  3 . 
     The sheath  6  is configured to assist the operation of the endoscopic clip EC. The sheath  6  is configured to have a proximal end connected to the distal end  2   t  of the operation portion  2  and a distal end, wherein the wire  5  is inserted through the sheath  6 , and the endoscopic clip EC is exposed from the distal end of the sheath  6 . 
     The endoscopic clip EC is configured to ligate openings, the blood vessels and the like formed in the human body. The endoscopic clip EC has an elastic member  7 , a pipe  8 , and an arm member (arm)  9 . 
     As shown in  FIG. 1  and  FIG. 2 , the arm member  9  is configured to transfer between a first position where the arm member  9  is pressed by the pipe  8  to be in a closed state and a second position where the arm member  9  is released from the pipe  8  to be in an open state due to the biasing force of the arm member  9  itself. 
     The elastic member  7  is configured to definitely move the arm member  9  toward the distal end side and make the arm member  9  to transfer to the second position in the case where the wire  5  moves toward the distal end side. The elastic member  7  is configured to bias the arm member  9  toward the second position when the arm member is positioned at the first position due to the restoring force. The elastic member  7  is configured to move the arm member  9  toward the distal end side by the restoring force when the wire  5  moves toward the distal end side, and the elastic member  7  releases the arm member  9  from the biased state when the arm member  9  transfers to the second position. 
     The slider  3  moves the arm member  9  into an operation range AA set in the second position by advancing the arm member  9  from a standby range WA set in the first position. 
     The protrusion  41 P of the grasping portion  41  and the protrusion  42 P of the grasped portion  42  cannot get over each other due to the compression force from the elastic member  7  via the slider  3 . 
     Operation of the treatment device  1  will be described.  FIG. 1  is a view showing the state before the usage of the treatment device  1 . In the state before the usage of the treatment device  1 , the sheath  6  is in a straight state. The biasing force by the elastic member  7  applies to the arm member  9 . The force toward the proximal end side by the slider restriction mechanism  4  via the wire  5  and the slider  3  applies to the arm member  9 . The biasing force by the elastic member  7  and the force by the slider restriction mechanism  4  are balanced with each other such that the arm member  9  is stationary at the first position. The slider restriction mechanism  4  restricts the operation of the slider  3  in the standby range WA (first range, first state). 
     The user pushes the operation portion  2  without applying any force to the slider  3  to make the treatment device  1  to pass through the endoscope channel (not shown) to reach the treatment target site. At this time, the first state is maintained. 
     As shown in  FIG. 2 , when the user makes the treatment device  1  reach the treatment target site and turns the endoscopic clip EC toward the opening I, the user strokes and advances the slider  3  toward the distal end side to move the arm member  9  to the second position. 
     As shown in  FIG. 3 , the user pulls back the slider  3  and moves the arm member  9  to the first position so as to grasp the edge of the opening I by the arm member  9  and close the opening I. 
     As shown in  FIG. 4 , the user pulls the slider  3  by a force exceeding a certain amount such that the arm member  9  is separated from the wire  5 . The arm member  9  separated from the wire  5  is pressed by the pipe  8  to maintain the closed state so as to be indwelled at the treatment target site while closing the opening I. 
     As shown in  FIG. 5 , in the treatment device  1 , the arm member  9  is operated to the second position by applying the force to make the protrusion  41 P of the grasping portion  41  to get over the protrusion  42 P of the grasped portion  42  and advance the slider  3 . The slider restriction mechanism  4  is contracted such that the operation range of the slider  3  is set to the standby range WA and the operation range AA (second range, second state). 
     As shown in  FIG. 6 , when the slider restriction mechanism  4  is in the second state and the user pulls back the slider  3  to the standby range WA, the arm member  9  returns to the first position again. When the user releases the force applied to the slider  3 , due to the storing force of the elastic member  7 , the slider  3  moves to the operation range AA and the arm member  9  moves to the second position again. Accordingly, even if a failure occurs during the operation of grasping the edge of the opening I to close the opening I, it is possible to perform the grasping operation again. 
     According to the treatment device  1  according to the present embodiment, the bias applied to the arm member  9  toward the distal end side in the standby range is suppressed by the slider restriction mechanism  4  via the wire  5  and the slider  3 . Accordingly, at the time of making the treatment device  1  reach the treatment target site while accommodating the arm member  9  in the pipe  8 , it is not necessary for the user to pull the slider  3 . 
     Next, an exemplary second embodiment of the present disclosure will be described by referring to  FIG. 7  to  FIG. 14 . 
     A treatment device  1 A according to the present embodiment, similar to the treatment device  1 , is a device configured to make the endoscopic clip EC, for example, reach a treatment target site by passing through the endoscope channel and operate the endoscopic clip EC. The treatment device  1 A is configured to have a slider restriction mechanism  4 A instead of the slider restriction mechanism  4  in the treatment device  1 . Accordingly, only the matters influenced by having the slider restriction mechanism  4 A instead of the slider restriction mechanism  4  will be described. 
     As shown in  FIG. 7 , the slider restriction mechanism  4 A has the grasping portion (first member)  41 , the grasped portion (second member)  42 , and a spring  43 . The spring  43  is sandwiched by the grasping portion  41  and the grasped portion  42 . Each of the grasping portion  41  and the grasped portion  42  has a hollow portion formed along an axial direction, and the wire  5  is inserted through the hollow portion. Each of the grasping portion  41  and the grasped portion  42  has an asymmetrical shape with respect to the axis. The slider restriction mechanism  4 A is contracted by applying a compression force in the axial direction which is larger than the restoring force of the spring  43 . Accordingly to the present embodiment, three protrusions  42 P of the grasped portion  42  are provided along the axial direction, however, it only has to provide at least one protrusion  42 P. 
     Operations of the treatment device  1 A will be described.  FIG. 7  is a view showing the state before the usage of the treatment device  1 A. In the state before the usage of the treatment device  1 A, the biasing force applied to the arm member  9  by the elastic member  7  and the force toward the proximal end side by the spring  43  are balanced with each other such that the arm member  9  is stationary at the first position. The slider  3  receives a resistance force by the spring  43  against advancement. 
       FIG. 8  is a view showing a state in which the user strokes the slider  3  toward the distal end side by a stroke amount in a range to maintain the arm member  9  at the first position when the sheath  6  is in the straight state. When the arm member  9  is in the range, the grasping portion  41  and the grasped portion  42  do not engage with each other. When the user releases the force applied to the slider  3 , the restoring force by the spring  43  of the slider restriction mechanism  4 A surpasses the restoring force of the elastic member  7  such that the slider restriction mechanism  4 A pushes back the slider  3 . The slider restriction mechanism  4 A restricts the operation of the slider  3  in the standby region WA (first state). 
     As shown in  FIG. 9 , in the treatment device  1 A, the sheath  6  is in the straight state, the arm member  9  transfers to the second position by applying a force resisting the restoring force of the spring  43  so as to make the protrusion  41 P of the grasping portion  41  to get over the most proximal protrusion  42 P of the grasped portion  42  and advance the slider  3 . The slider restriction mechanism  4 A is contracted such that the operation range of the slider  3  is set to the standby range WA and the operational range AA (second state). 
     The contraction of the slider restriction mechanism  4 A is an irreversible contraction to cancel the restoration of the spring  43  due to the engagement of the protrusion  41 P and the protrusion  42 P. 
     In the state, the slider restriction mechanism  4 A does not push back the slider  3  toward the proximal end side by the restoring force of the spring  43 . Accordingly, even if the user releases the force applied to the slider  3 , the slider  3  is maintained in the operational range AA due to the restoring force of the elastic member  7 . The slider restriction mechanism  4 A is contracted such that the operation range of the slider  3  is set to the standby range WA and the operational range AA (second state). 
     As shown in  FIG. 10 , when the slider restriction mechanism  4 A is in the second state and the user pulls the slider  3  back to the standby range WA, the arm member  9  takes the first position again. When the user releases the force applied to the slider  3 , the slider  3  moves to the operational range AA due to the restoring force of the elastic member  7  such that the arm member  9  takes the second position again. Accordingly, even if a failure occurs during the operation of grasping the edge of the opening I to close the opening I, it is possible to perform the grasping operation again. 
     As shown in  FIG. 11 , the treatment device  1 A is configured to substantially extend the sheath  6  when the sheath  6  is in a bending state. The sheath  6  applies a force toward the distal end side to the endoscopic clip EC due to the substantial extension. Accordingly, the slider restriction mechanism  4 A is compressed to be contracted via the wire  5  and the slider  3  so as to advance the slider  3  toward the distal end side. Compared with the situation when the sheath  6  is in the straight state, the standby range WA is expanded at the side of the distal end  2   t  of the operation portion  2 . The contraction of the slider restriction mechanism  4 A is a reversible contraction due to the elastic deformation of the spring  43 . 
       FIG. 11  is a view showing a state in which the arm member  9  is in the range to maintain the first position when the sheath  6  is in the bending state. The arm member  9  is in the range such that the grasping portion  41  and the grasped portion  42  do not engage with each other. In the range, the user strokes the slider  3  toward the distal end side and then releases the force applied to the slider  3 , the restoring force by the spring  43  of the slider restriction mechanism  4 A surpasses the restoring force of the elastic member  7  such that the slider restriction mechanism  4 A pushes back the slider  3 . The slider restriction mechanism  4 A restricts the operation of the slider  3  in the standby region WA (first state). 
     As shown in  FIG. 12 , when the sheath  6  is in the bent state, the arm member  9  transfers to the second position by applying a force resisting the restoring force of the spring  43  so as to make the protrusion  41 P of the grasping portion  41  to get over the most proximal protrusion  42 P of the grasped portion  42  and advance the slider  3 . The slider restriction mechanism  4 A is contracted such that the operation range of the slider  3  is set to the standby range WA and the operational range AA (second state). 
     The contraction of the slider restriction mechanism  4 A is an irreversible contraction to cancel the restoration of the spring  43  due to the engagement of the protrusion  41 P and the protrusion  42 P. 
     In the state, the slider restriction mechanism  4 A does not push back the slider  3  toward the proximal end side by the restoring force of the spring  43 . Accordingly, even if the user releases the force applied to the slider  3 , the slider  3  is maintained in the operational range AA due to the restoring force of the elastic member  7 . The slider restriction mechanism  4 A is contracted such that the operation range of the slider  3  is set to the standby range WA and the operational range AA (second state). 
     When the slider restriction mechanism  4 A is in the second state and the user pulls the slider  3  back to the standby range WA, the arm member  9  takes the first position again. When the user releases the force applied to the slider  3 , the slider  3  moves to the operational range AA due to the restoring force of the elastic member  7  such that the arm member  9  takes the second position again. Accordingly, even if a failure occurs during the operation of grasping the edge of the opening I to close the opening I, it is possible to perform the grasping operation again. 
     As shown in  FIG. 13 , the treatment device  1 A is configured to substantially extend the sheath  6  when the sheath  6  is in the once-wrapped state. The sheath  6  applies a force toward the distal end side to the endoscopic clip EC due to the substantial extension. Accordingly, the slider restriction mechanism  4 A is compressed to be contracted via the wire  5  and the slider  3  so as to advance the slider  3  toward the distal end side. Compared with the situation when the sheath  6  is in the bent state, the standby range WA is expanded at the side of the distal end  2   t  of the operation portion  2 . The contraction of the slider restriction mechanism  4 A is a reversible contraction due to the elastic deformation of the spring  43 . 
       FIG. 13  is a view showing a state in which the arm member  9  is in the range to maintain the first position when the sheath  6  is in the once-wrapped state. The arm member  9  is in the range such that the grasping portion  41  and the grasped portion  42  do not engage with each other. In the range, the user strokes the slider  3  toward the distal end side and then releases the force applied to the slider  3 , the restoring force by the spring  43  of the slider restriction mechanism  4 A surpasses the restoring force of the elastic member  7  such that the slider restriction mechanism  4 A pushes back the slider  3 . The slider restriction mechanism  4 A restricts the operation of the slider  3  in the standby region WA (first state). 
     As shown in  FIG. 14 , when the sheath  6  is in the once-wrapped state, the arm member  9  transfers to the second position by applying a force resisting the restoring force of the spring  43  so as to make the protrusion  41 P of the grasping portion  41  to get over the most proximal protrusion  42 P of the grasped portion  42  and advance the slider  3 . The slider restriction mechanism  4 A is contracted such that the operation range of the slider  3  is set to the standby range WA and the operational range AA (second state). 
     The contraction of the slider restriction mechanism  4 A is an irreversible contraction to cancel the restoration of the spring  43  due to the engagement of the protrusion  41 P and the protrusion  42 P. 
     In the state, the slider restriction mechanism  4 A does not push back the slider  3  toward the proximal end side by the restoring force of the spring  43 . Accordingly, even if the user releases the force applied to the slider  3 , the slider  3  is maintained in the operational range AA due to the restoring force of the elastic member  7 . The slider restriction mechanism  4 A is contracted such that the operation range of the slider  3  is set to the standby range WA and the operational range AA (second state). 
     When the slider restriction mechanism  4 A is in the second state and the user pulls the slider  3  back to the standby range WA, the arm member  9  takes the first position again. When the user releases the force applied to the slider  3 , the slider  3  moves to the operational range AA due to the restoring force of the elastic member  7  such that the arm member  9  takes the second position again. Accordingly, even if a failure occurs during the operation of grasping the edge of the opening I to close the opening I, it is possible to perform the grasping operation again. 
     According to the treatment device  1 A according to the present embodiment, despite of the bending state of the sheath  6 , the bias toward the distal end side applied to the arm member  9  in the standby range WA is suppressed by the slider restriction mechanism  4 A via the wire  5  and the slider  3 . Accordingly, despite of the bending state of the sheath  6 , at the time of making the treatment device  1 A reach the treatment target site while accommodating the arm member  9  in the pipe  8 , it is not necessary for the user to pull the slider  3 . 
     Furthermore, the spring  43  has the resistance force against the advancement of the slider  3  such that even if the user does not pull the slider  3 , the arm member  9  will not project out suddenly. For example, the arm member will not project out to damage the mucous membrane at the treatment target site. 
     Next, an exemplary third embodiment of the present disclosure will be described by referring to  FIG. 15  to  FIG. 20 . 
     A treatment device  1 B according to the present embodiment, similar to the treatment device  1 , is a device configured to make the endoscopic clip EC, for example, reach a treatment target site by passing through the endoscope channel and operate the endoscopic clip EC. The treatment device  1 B is configured to have a slider restriction mechanism  10  instead of the slider restriction mechanism  4 A in the treatment device  1 A. 
       FIG. 15  is a perspective view of the slider restriction mechanism  10  of the treatment device  1 B.  FIG. 16  is a planar view of the slider restriction mechanism  10 . As shown in  FIGS. 15 and 16 , the slider restriction mechanism  10  is a spiral spring, wherein the coils of the spiral spring is separated from the axial direction from the inside coil to the outside coil. 
     The slider restriction mechanism  10  is designed to have a strength distribution that as the compression force applied long the axial direction increases, the coils yield in a sequence from the inside coil to the outside coil. A yield point F 2  of a second coil  12  is larger than the yield point F 1  of the most inside coil  11 . The yield point F 3  of a third coil  13  is larger than the yield point F 2  of the second coil  12 . 
     According to the present embodiment, with regard to the slider restriction mechanism  10 , a number of the wound coils of the spiral spring is determined to be three windings along the axial direction excluding the end coil  14 , however, only one or more windings has to be formed. 
     Operations of the treatment device  1 B will be described. The only one difference between the operations of the treatment device  1 B and that of the treatment device  1 A is that manners of the dimension reduction in the axial direction between the slider restriction mechanism  10  and the slider restriction mechanism  4 A are different from each other. Accordingly, the manner of the dimension reduction in the axial direction of the slider restriction mechanism  10  will be described. 
       FIG. 17  is a view showing the state before the usage of the treatment device  1 B. In the state before the usage of the treatment device  1 B, the force toward the proximal end side by the slider restriction mechanism  10  and via the wire  5  and the slider  3  is applied to the arm member  9 . The biasing force by the elastic member  7  and the force by the slider restriction mechanism  10  are balanced with each other such that the arm member  9  is in the stationary state at the first position. 
     The treatment device  1 B is configured to restrict the operations of the slider  3  in the standby region WA due to the elasticity provided by the slider restriction mechanism  10  (first state). 
     As shown in  FIG. 18 , the treatment device  1 B is configured that the compression force F 1  applies to the coil  11  so as to cause the coil  11  to yield at the stroke amount that the arm member  9  is at the second position when the sheath  6  is in the straight state. Since the coil  11  yields to the compression force F 1 , the dimension in the axial direction of the slider restriction mechanism  10  reduces. The slider restriction mechanism  10  is contracted such that the operation range of the slider  3  becomes to the standby range WA and the operational range AA (second state). 
     As shown in  FIG. 19 , the treatment device  1 B is configured that the sheath  6  substantially extends to be longer when the sheath  6  is in the bending state, the compression force F 2  applies to the coil  12  so as to cause the coil  12  to yield at the stroke amount that the arm member  9  is at the second position. Since the coil  12  yields to the compression force F 2 , the dimension in the axial direction of the slider restriction mechanism  10  reduces. The slider restriction mechanism  10  is contracted such that the operation range of the slider  3  becomes to the standby range WA and the operational range AA (second state). 
     As shown in  FIG. 20 , the treatment device  1 B is configured that the sheath  6  substantially extends to be longer when the sheath  6  is in the once-wrapped state, the compression force F 3  applies to the coil  13  so as to cause the coil  13  to yield at the stroke amount that the arm member  9  is at the second position. Since the coil  13  yields to the compression force F 3 , the dimension in the axial direction of the slider restriction mechanism  10  reduces. The slider restriction mechanism  10  is contracted such that the operation range of the slider  3  becomes the standby range WA and the operational range AA (second state). 
     According to the treatment device  1 B according to the present embodiment, despite of the bending state of the sheath  6 , the bias toward the distal end side applied to the arm member  9  in the standby range WA is suppressed by the slider restriction mechanism  10  via the wire  5  and the slider  3 . Accordingly, despite of the bending state of the sheath  6 , at the time of making the treatment device  1 A reach the treatment target site while accommodating the arm member  9  in the pipe  8 , it is not necessary for the user to pull the slider  3 . 
     Furthermore, the slider restriction mechanism  10  has the resistance force against the advancement of the slider  3  such that even if the user does not pull the slider  3 , the arm member  9  will not project out suddenly. For example, the arm member will not project out to damage the mucous membrane at the treatment target site. 
     The exemplary embodiments have been described above with reference to the drawings, but the technical scope of the present disclosure is not limited to the embodiments and may include various modifications without departing from the scope of the disclosure. The configuration elements shown in the above-described embodiments and the following modifications can be properly combined. 
     For example, the treatment device  1  and the treatment device  1 A may be configured to have the grasping portion  41  and the slider  3  to be integrally configured, or have the grasped portion  42  and the operation portion  2  to be integrally configured. 
     The treatment device  1  and the treatment device  1 A may be configured to have the grasping portion  41  at the distal end side and the grasped portion  42  at the proximal end side. 
     With regard to the treatment device  1 , the treatment device  1 A, and the treatment device  1 B, the arm member  9  may be configured as a pair of forceps such as the biopsy forceps or the grasping forceps. 
     With regard to the slider restriction mechanism  10  of the treatment device  1 B, the slider restriction mechanism may be configured as a plurality of springs having different yield points and being provided continuously along the sliding direction of the slider rather than the spiral spring. 
     With regard to the slider restriction mechanism  4  of the treatment device  1 , the slider restriction mechanism  4 A of the treatment device  1 A, and the slider restriction mechanism  10  of the treatment device  1 B, they may attached to the treatment device  1 , the treatment device  1 A, and the treatment device  1 B respectively in advance, and they may configured to be attachable thereto at the time of being used by the user. 
     The endoscopic clip EC included in the treatment device  1 , the treatment device  1 A, and the treatment device  1 B may be configured to exclude the elastic member  7 . The arm member  9  is biased in the open state, and the distal end of the arm member  9  is exposed from the pipe  8  such that the arm member  9  comes in contact with the distal end of the pipe  8 . Accordingly, the arm member  9  applies the force toward the proximal end side to the distal end of the pipe  8 , and the reaction force makes the arm member  9  to be biased toward the distal end side such that the arm member  9  can be biased toward the distal end side without providing the elastic member  7 .