Abstract:
A medical treatment implement including: a shaft extending along a longitudinal axis; a housing having distal and proximal portions, a proximal end of the shaft being attached to the distal portion of the housing to extend from the distal to the proximal portion, the elongated shaft being rotatable about the longitudinal axis relative to the housing; an effector attached to a distal end of the shaft, the effector articulating relative to the longitudinal axis; a drive mechanism having an output connected to the effector to articulate the effector relative to the shaft; and an input unit attached to the housing at a position closer to the proximal portion than the distal portion, wherein the input unit receives an operation input and directly inputs the drive mechanism in response to the input, wherein the input unit rotates about the longitudinal axis together with the shaft relative to the housing.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application is a continuation of PCT/JP2016/065296 filed on May 24, 2016, which is based upon and claims the benefit to JP 2015-179147 filed on Sep. 11, 2015, the entire contents of each of which are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    Field 
         [0003]    The present application relates to a medical treatment implement in which an end effector for treating a treatment target articulates with respect to an elongated shaft. 
         [0004]    Prior Art 
         [0005]    The specification of U.S. Unexamined Patent Application Publication No. 2015/0066022 and the specification of U.S. Unexamined Patent Application Publication No. 2015/0090766 each describe a medical treatment implement in which a sheath is installed to a holdable housing such that the sheath is rotatable about a longitudinal axis. In each of these medical treatment implements, the sheath and an end effector rotate about the longitudinal axis with respect to the housing in response to an operation input supplied through a rotation control knob (rotation control input unit) provided on the sheath. Further, in each of the treatment implements, the end effector can be articulated with respect to the sheath, and the angle of the end effector with respect to the sheath (the longitudinal axis) changes when the end effector articulates. As the articulation control input unit through which the operation input for articulating the end effector is supplied, an articulation control dial is attached to the housing according to the specification of the foregoing U.S. Unexamined Patent Application Publication No. 2015/0066022, and an articulation control knob is attached to the outer peripheral surface of a rotation control knob (sheath) according to the specification of the foregoing U.S. Unexamined Patent Application Publication No. 2015/0090766. 
         [0006]    According to the specification of U.S. Unexamined Patent Application Publication No. 2015/0066022, the articulation control dial rotates independently of the rotation control knob (sheath), so that when the rotation control knob is rotated about the longitudinal axis, the articulation control dial does not rotate together with the sheath and the end effector. Hence, the relative relationship between the articulation direction of the end effector and the operational direction (the rotational direction) set by the articulation control dial changes as the angular position of the end effector about the longitudinal axis is changed in response to an operation input supplied through the rotation control knob. This makes it difficult for an operator to know the articulation direction of the end effector, leading to deteriorated ease of operation for articulating the end effector. 
         [0007]    According to the specification of U.S. Unexamined Patent Application Publication No. 2015/0090766, the articulation control knob is attached to the outer peripheral surface of the rotation control knob connected to the distal side of the housing and rotates about the longitudinal axis together with the rotation control knob. This makes it difficult to give an operation input through the articulation control knob by using only the hand holding the housing (i.e. one hand), depending on the angular position of the articulation control knob about the longitudinal axis. Thus, ease of operation for articulating the end effector is deteriorated. 
       SUMMARY 
       [0008]    The present embodiments have been made with a view toward solving the above problem, and an object is to provide a medical treatment implement that ensures ease of operation for articulating an end effector with respect to a sheath regardless of the angular position of the end effector about a longitudinal axis. 
         [0009]    Accordingly, a medical treatment implement comprising: an elongated shaft configured to extend along a longitudinal axis; a housing comprising a distal portion and a proximal portion, a proximal end of the elongated shaft being attached to the distal portion of the housing such that the longitudinal axis extends from the distal portion to the proximal portion, wherein the elongated shaft is configured to be rotatable about the longitudinal axis with respect to the housing; an end effector attached to a distal end of the elongated shaft, wherein the end effector is configured to articulate with respect to the longitudinal axis of the elongated shaft; a drive mechanism having an output connected to the end effector, the drive mechanism configured to articulate the end effector with respect to the elongated shaft; and an articulation control input unit attached to the housing at a position closer to the proximal portion than the distal portion, wherein the articulation control input unit is configured to receive an operation input and directly input the drive mechanism in response to the operation input, wherein the articulation control input unit is configured to rotate about the longitudinal axis together with the elongated shaft with respect to the housing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  illustrates a schematic diagram of a medical treatment implement according to a first embodiment; 
           [0011]      FIG. 2  illustrates a schematic perspective view of the configuration of an end effector according to the first embodiment; 
           [0012]      FIG. 3  illustrates a schematic perspective view of the internal configuration of a housing according to the first embodiment; 
           [0013]      FIG. 4  illustrates a schematic sectional view of the internal configuration of the housing according to the first embodiment, which is observed at a section substantially perpendicular to the direction of the width of the housing; 
           [0014]      FIG. 5  illustrates a schematic sectional view of the internal configuration of the housing according to the first embodiment, which is observed at a section substantially parallel to the direction of a longitudinal axis and substantially parallel to the direction of the width of the housing; 
           [0015]      FIG. 6  illustrates a schematic perspective view of the configuration of an end effector according to a first modification example; 
           [0016]      FIG. 7  illustrates a schematic sectional view of the configuration of an articulation control dial and the vicinity thereof according to a second modification example; 
           [0017]      FIG. 8  illustrates a schematic sectional view of the configuration of an articulation control lever and the vicinity thereof according to a third modification example; 
           [0018]      FIG. 9  illustrates a schematic sectional view of the configuration of an articulation control dial and the vicinity thereof according to a fourth modification example; 
           [0019]      FIG. 10  illustrates a schematic diagram of a medical treatment implement according to a fifth modification example; 
           [0020]      FIG. 11  illustrates a schematic diagram of a rotation control knob, a rotation base and an articulation control dial according to a fifth modification example, which are observed from a proximal side; and 
           [0021]      FIG. 12  illustrates a schematic perspective view of the internal configuration of a housing according to the fifth modification example. 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     First Embodiment 
       [0022]    A first embodiment will be described with reference to  FIG. 1  to  FIG. 5 . 
         [0023]      FIG. 1  is a diagram illustrating the configuration of a medical treatment implement  1  according to the present embodiment. As illustrated in  FIG. 1 , the medical treatment implement  1  has a holdable housing  3  and a tubular sheath (an elongated shaft)  5  connected to the housing  3 . The sheath  5  extends along a longitudinal axis (central axis) C. Here, the direction along the longitudinal axis C is defined as the longitudinal axis direction. One end in the longitudinal axis direction is defined as the distal side (arrow C 1  side in  FIG. 1 ), and the opposite side from the distal side is defined as the proximal side (arrow C 2  side in  FIG. 1 ). The sheath  5  is extended along the longitudinal axis C from the proximal side to the distal side and connected to the distal side of the housing  3 . The housing  3  includes a distal end outer surface  3 A, which forms the distal end of the housing  3 , and a proximal end outer surface  3 B, which forms the proximal end of the housing  3 . The distal end outer surface  3 A is directed toward the distal side, while the proximal end outer surface  3 B is directed toward the proximal side. 
         [0024]    The sheath  5  is installed to be rotatable about the longitudinal axis C with respect to the housing  3 . The sheath  5  has a pipe  10  and a rotation control knob  18 , which is a rotation control input unit attached to the proximal end portion of the pipe  10 . The proximal end portion of the pipe  10  is inserted from the distal side into the rotation control knob  18  and fixed to the rotation control knob  18 . Further, the pipe  10  is extended from the rotation control knob  18  toward the distal side. Further, an end effector  7  for treating a treatment target is attached to the distal side of the sheath  5  (the pipe  10 ). When the rotation control knob  18  is rotated about the longitudinal axis C with respect to the housing  3 , the operation of rotating the end effector  7  about the longitudinal axis C is input through the rotation control knob  18 . The operation input through the rotation control knob  18  causes a driving force (rotational driving force) to be transmitted to the sheath  5 , and the sheath  5  rotates about the longitudinal axis C (i.e. together with the rotation control knob  18  and the pipe  10 ) with respect to the housing  3 . 
         [0025]      FIG. 2  is a diagram illustrating the configuration of the end effector  7 . As illustrated in  FIG. 2 , the end effector  7  has an effector base  11  attached to the sheath  5  (the pipe  10 ), a first gripping piece  12  fixed to the effector base  11  and a second gripping piece  13  pivotably connected to the effector base  11 . The effector base  11  is attached to the sheath  5  such that the effector base  11  is pivotable about a pivot axis (articulation pivot axis) P 1  with respect to the sheath  5 . The pivot axis P 1  extends along a direction that intersects with (being substantially perpendicular to) the longitudinal axis C direction of the sheath  5 . As the end effector  7  including the effector base  11  pivots about the pivot axis P 1  with respect to the sheath  5 , the end effector  7  articulates with respect to the sheath  5 , as denoted by an arrow B 1  and an arrow B 2  in  FIG. 2 . The articulation of the end effector  7  causes a change in an articulation angle (angle) α of the end effector  7  with respect to the longitudinal axis C of the sheath  5 . 
         [0026]    The second gripping piece  13  can be pivoted about a pivot axis (opening/closing pivot axis) P 2  with respect to the effector base  11 . The pivot axis P 2  extends along a direction which intersects with (being substantially perpendicular to) a longitudinal axis C direction and also intersects with (being substantially perpendicular to) the direction in which the pivot axis P 1  extends. When the second gripping piece  13  pivots about the pivot axis P 2 , the space between the first gripping piece  12  and the second gripping piece  13  increases or decreases in the end effector  7 . More specifically, when the second gripping piece  13  pivots, the end effector  7  opens or closes, as denoted by an arrow Y 1  and an arrow Y 2  in  FIG. 2 . Both the first gripping piece  12  and the second gripping piece  13  may be attached to be pivotable with respect to the effector base  11  (e.g. about the pivot axis P 2 ). In this case, the first gripping piece  12  and the second gripping piece  13  are moved away from or toward each other by pivoting the first gripping piece  12  and the second gripping piece  13  so as to open or close the end effector  7 . In the present embodiment, a treatment target, such as a body tissue, is grasped between the first gripping piece  12  and the second gripping piece  13  in order to treat the treatment target. 
         [0027]    As illustrated in  FIG. 1 , the housing  3  has a housing main body  15 , which is extended along the longitudinal axis C, and a grip (fixed handle)  16 , which is extended from the housing main body  15  in a direction away from the longitudinal axis C. The sheath  5  formed of the pipe  10  and the rotation control knob  18  is connected to the housing main body  15  from the distal side. A lever (movable handle)  17  is pivotably attached to the housing  3 . The lever  17  is positioned on the side where a grip  16  is positioned with respect to the longitudinal axis C, and positioned on the distal side with respect to the grip  16  in the present embodiment. As the lever  17  pivots with respect to the housing  3  and the lever  17  opens or closes with respect to the grip  16 , the operation for opening or closing the end effector  7  as described above is input through the lever  17 , which is an opening/closing control input unit. 
         [0028]    Further, an articulation control dial  20 , which is an articulation control input unit, is attached to the housing  3 . The articulation control dial  20  is positioned on the proximal side apart from the rotation control knob  18 . An operation for articulating the end effector  7  as described above is input through the articulation control dial  20 . 
         [0029]    Further, control buttons  19 A,  19 B, which are energy control input sections, are attached to the housing  3  (a housing distal end outer surface  3 A in the present embodiment). Applying an operation input through the control button  19 A supplies a high-frequency electric energy to, for example, the gripping pieces  12  and  13 . Thus, a high-frequency current is applied to the treatment target held between the gripping pieces  12  and  13  to treat the treatment target. Applying an operation input through the control button  19 B supplies electric energy to, for example, a heating element (not illustrated) provided in the end effector  7 . Thus, the heat generated by the heating element is used to treat the treatment target. The energy supplied to the end effector  7  is not limited to the foregoing energy. Other types of energy used for treatment may be supplied to the end effector  7  by applying an operation input through the control button  19 A or  19 B. 
         [0030]      FIG. 3  to  FIG. 5  are diagrams illustrating the internal configuration of the housing main body  15  of the housing  3  and the internal configuration of the rotation control knob  18 .  FIG. 3  is a perspective view,  FIG. 4  illustrates a section substantially perpendicular to (intersecting with) the width direction (the direction of an arrow W in  FIG. 3  and  FIG. 5 ) of the housing  3 , and  FIG. 5  illustrates a section which is substantially parallel to the longitudinal axis C direction and which is also substantially parallel to the width direction of the housing  3 . 
         [0031]    As illustrated in  FIG. 3  to  FIG. 5 , in the housing  3  (the housing main body  15 ), an opening  21  that opens toward the distal side (on an arrow C 1  side in  FIG. 3  to  FIG. 5 ) is formed at a reference position X 1 . The sheath  5  (the assembly composed of the rotation control knob  18  and the pipe  10 ) is inserted into the housing  3  from the distal side through the opening  21  at the reference position X 1  and installed to the housing  3 . Further, the sheath  5  is connected to the distal side of the housing  3  such that the sheath  5  projects toward the distal side from the reference position X 1  of the housing  3  (the housing main body  15 ). In the present embodiment, the reference position X 1  is on the distal end outer surface  3 A of the housing  3  and at the distal end of the housing main body  15 . According to the present embodiment, therefore, the sheath  5  (the assembly composed of the rotation control knob  18  and the pipe  10 ) is inserted into the housing main body  15  from the distal end outer surface  3 A of the housing  3 . 
         [0032]    In the housing  3  (the housing main body  15 ), a tubular movable member  22  is attached to the sheath  5  (the rotation control knob  18 ) from the proximal side (an arrow C 2  side in  FIG. 3  to  FIG. 5 ). The movable member  22  is extended along the longitudinal axis C and is capable of moving along the longitudinal axis C with respect to the housing  3  and the sheath  5  (the rotation control knob  18  and the pipe  10 ). However, the rotation of the movable member  22  about the longitudinal axis C with respect to the sheath  5  is restricted. In the housing  3 , the lever  17  is connected to the movable member  22  through the intermediary of a slider (not illustrated) disposed on the outer peripheral surface of the movable member  22 . The movable member  22  is connected to the lever  17  such that the movable member  22  is rotatable about the longitudinal axis C with respect to the lever  17 . Further, inside the housing  3 , a drive shaft  25 , which is an opening/closing drive member, is fixed to the movable member  22  through the intermediary of a connection member  23 . The drive shaft  25  is extended along the longitudinal axis C from the inside of the movable member  22  toward the distal side through the inside of the sheath  5 . 
         [0033]    When an operation input is supplied through the rotation control knob  18 , the rotation control knob  18  rotates about the longitudinal axis C, thus transmitting a driving force (rotational driving force) to the movable member  22  attached to the rotation control knob  18 . This causes the movable member  22  and the drive shaft  25  to rotate, with respect to the housing  3 , about the longitudinal axis C together with the sheath  5  (the pipe  10 ) attached to the rotation control knob  18 . Since the sheath  5  is fixed to the rotation control knob  18 , the driving force (rotational driving force) is transmitted to the movable member  22  through the intermediary of the rotation control knob  18  when the sheath  5  is rotated. Further, the movable member  22  and the drive shaft  25  move along the longitudinal axis C with respect to the sheath  5  and the housing  3  when an operation input is supplied to release or squeeze the lever  17  with respect to the grip  16 . 
         [0034]    As illustrated in  FIG. 2 , the drive shaft  25  extended through the inside of the sheath  5  has one end (the distal end) thereof connected to the second gripping piece  13  of the end effector  7 . As the lever  17  is released or squeezed with respect to the grip  16 , the movable member  22  and the drive shaft  25  move along the longitudinal axis C, and the second gripping piece  13  pivots about the pivot axis P 2 , thus opening or closing the end effector  7  as described above. Further, according to the present embodiment, the drive shaft  25  is rotatable about the longitudinal axis C together with the sheath  5  (the rotation control knob  18  and the pipe  10 ). Hence, in response to an operation input supplied through the rotation control knob  18 , the end effector  7  rotates about the longitudinal axis C with respect to the housing  3  together with the sheath  5  and the drive shaft  25 . As the end effector  7  rotates about the longitudinal axis C, the angular position of the end effector  7  about the longitudinal axis C with respect to the housing  3  changes. 
         [0035]    Further, as the end effector  7  rotates, the pivot axes P 1  and P 2  also rotate about the longitudinal axis C with respect to the housing  3 , and the extending directions of the pivot axes P 1  and P 2  change accordingly. Thus, the articulation direction of the articulating movement of the end effector  7  (the directions of the arrow B 1  and the arrow B 2  in  FIG. 2 ) changes and the opening/closing direction (the directions of the arrow Y 1  and the arrow Y 2  in  FIG. 2 ) of the opening/closing movement thereof also changes. However, the articulation direction of the end effector  7  intersects with (being substantially perpendicular to) the direction of the longitudinal axis C, and the opening/closing direction of the end effector  7  intersects with (being substantially perpendicular to) the direction of the longitudinal axis C and also intersects with (being substantially perpendicular to) the articulation direction of the articulation movement, regardless of the angular position of the end effector  7  about the longitudinal axis C. 
         [0036]    As illustrated in  FIG. 3  to  FIG. 5 , the articulation control dial  20 , which is an articulation control input unit, is attached to the housing  3  through the intermediary of a rotation base  30 , which is a base member. The rotation base  30  and the articulation control dial  20  are positioned closer to the proximal side than the reference position X 1  (the distal end outer surface  3 A in the present embodiment) of the housing  3 , at which the opening  21  is formed. In the present embodiment, the rotation base  30  and the articulation control dial  20  are attached to an installation outer surface  27 , which is directed to the proximal side in the housing main body  15  (the outer surface thereof). The rotation base  30  and the articulation control dial  20  are rotatable about the longitudinal axis C with respect to the installation outer surface  27 , i.e. the housing  3 . Further, according to the present embodiment, the installation outer surface  27  forms the proximal end outer surface  3 B of the housing  3  and forms the proximal end of the housing main body  15 . 
         [0037]    The articulation control dial  20  is attached to the rotation base  30  through the intermediary of a support shaft  31 . The articulation control dial  20  is rotatable about a rotation axis R 1 , which is the central axis of the support shaft  31 , with respect to the rotation base  30 . The articulation control dial  20  is rotated about the rotation axis R 1  to supply an operation input for articulating the end effector  7 . At this time, the directions denoted by an arrow Q 1  and an arrow Q 2  in  FIG. 5  are the directions of the operation of the articulation control dial  20 . The rotation axis R 1  is extended along the direction that intersects with (being substantially perpendicular to) the longitudinal axis C direction of the sheath  5 . Further, the articulation control dial  20  has a gear  28  formed over the whole circumference around the rotation axis R 1 . In the present embodiment, the gear  28  is disposed inside the housing  3  without being exposed outside the housing  3 . 
         [0038]    A pulley  35  is installed to the rotation base  30  through the intermediary of a support shaft  36 . In the present embodiment, the pulley  35  is positioned inside the housing main body  15  and positioned at the distal side with respect to the articulation control dial  20 . The pulley  35  is rotatable about a rotation axis R 2 , which is the central axis of the support shaft  36 , with respect to the rotation base  30 . The rotation axis R 2  is extended to intersect with (being substantially perpendicular to) the longitudinal axis C direction of the sheath  5  and also along the direction substantially parallel to the rotation axis R 1 . Further, the pulley  35  has a gear  37  formed over the whole circumference around the rotation axis R 2 . The gear  37  meshes with the gear  28  of the articulation control dial  20 . 
         [0039]    The proximal ends (one ends) of articulation wires  41 A,  41 B, which are articulation drive members (drive members), are connected to the pulley  35 . The articulation wires  41 A,  41 B are extended along the longitudinal axis C toward the distal side through the inside of the movable member  22  and the inside of the sheath  5 . As illustrated in  FIG. 2 , the distal ends (the other ends) of the articulation wires  41 A,  41 B are connected to an effector base  11  of the end effector  7 . As the articulation control dial  20  rotates about the rotation axis R 1  with respect to the rotation base  30  in response to an operation input, the pulley  35  rotates about the rotation axis R 2 . Thus, the articulation wires  41 A,  41 B, which are the articulation drive members, are driven, and the articulation wires  41 A,  41 B move along the longitudinal axis C with respect to the sheath  5 . As the articulation wires  41 A,  41 B move, the end effector  7  articulates with respect to the sheath  5 , as described above. 
         [0040]    For example, if the articulation control dial  20  is rotated to one side (to the side denoted by an arrow T 1  in  FIG. 5 ) by the operation input for moving the articulation control dial  20  to one side of the operational direction (to the side denoted by an arrow Q 1  in  FIG. 5 ), then the pulley  35  rotates to one side (to the side denoted by an arrow Z 1  in  FIG. 5 ) of the rotational direction. Thus, the articulation wire  41 A moves to the proximal side (to be tightened) while the articulation wire  41 B moves to the distal side (to be loosened), causing the end effector  7  to articulate to one side (to the side denoted by the arrow B 1  in  FIG. 2 ) of the articulation direction with respect to the sheath  5  (the longitudinal axis C). Meanwhile, if the articulation control dial  20  is moved to the other side (to the side denoted by an arrow T 2  in  FIG. 5 ) by the operation input for moving the articulation control dial  20  to the other side of the operational direction (to the side denoted by an arrow Q 2  in  FIG. 5 ), then the pulley  35  rotates to the other side (to the side denoted by an arrow Z 2  in  FIG. 5 ) of the rotational direction. Thus, the articulation wire  41 B moves to the proximal side while the articulation wire  41 A moves to the distal side, causing the end effector  7  to articulate to the other side (to the side denoted by the arrow B 2  in  FIG. 2 ) of the articulation direction with respect to the sheath  5  (the longitudinal axis C). 
         [0041]    Here, a state in which the angle of the end effector  7  with respect to the sheath  5  is zero degrees (a position at which the end effector  7  is not articulated with respect to the sheath  5 ) is defined as the neutral state. According to the present embodiment, the ratio of an articulation angle α (the amount of articulation) of the end effector  7  from the neutral state with respect to the amount of rotation (the manipulated variable based on an operation input) of the articulation control dial  20  from the neutral state is set on the basis of the gear ratio between the gear  28  and the gear  37 . Hence, at the time of manufacturing the medical treatment implement  1 , the ratio of the articulation angle α of the end effector  7  from the neutral state with respect to the amount of rotation of the articulation control dial  20  from the neutral state is adjusted by adjusting the gear ratio between the gear  28  and the gear  37 . 
         [0042]    Further, inside the housing main body  15 , the rotation base  30  is connected to the movable member  22  from the proximal side. The movable member  22  is movably connected along the longitudinal axis C with respect to the rotation base  30 . Further, the rotations of the movable member  22  and the rotation base  30  about the longitudinal axis C with respect to each other are restricted. Therefore, the movable member  22 , which connects the sheath  5  (the rotation control knob  18  and the pipe  10 ) and the articulation control dial  20  (the rotation base  30 ), is rotatable about the longitudinal axis C together with the sheath  5  and the articulation control dial  20  and is movable along the longitudinal axis C with respect to the sheath  5  and the articulation control dial  20 . 
         [0043]    With the foregoing configuration, the end effector  7 , the sheath  5 , the movable member  22 , and the drive shaft  25  rotate about the longitudinal axis C in response to the operation input through the rotation control knob  18 , thus transmitting the driving force (the rotational driving force) to the rotation base  30  from the sheath  5  through the movable member  22 . This causes the rotation base  30  to rotate about the longitudinal axis C together with the end effector  7 , the sheath  5 , the movable member  22 , and the drive shaft  25  with respect to the installation outer surface  27 . At this time, the driving force (the rotational driving force) is transmitted from the rotation base  30  also to the articulation control dial  20 , the pulley  35 , and the support shafts  31 ,  36 , which are installed to the rotation base  30 . The articulation control dial  20 , the pulley  35 , and the support shafts  31 ,  36  rotate about the longitudinal axis C together with the rotation base  30  with respect to the installation outer surface  27 . In other words, according to the present embodiment, as the sheath  5  rotates about the longitudinal axis C with respect to the housing  3  in response to the operation input supplied through the rotation control knob  18 , which is the rotation control input unit, the articulation control dial  20 , which is the articulation control input unit, and the end effector  7  also rotate about the longitudinal axis C together with the sheath  5  with respect to the housing  3 . Further, as the end effector  7  and the pulley  35  rotate about the longitudinal axis C in response to an operation input supplied through the rotation control knob  18 , the articulation wires  41 A,  41 B connecting the end effector  7  and the pulley  35  also rotate about the longitudinal axis C. 
         [0044]    Further, the rotation of the rotation base  30  and the members, such as the articulation control dial  20 , installed to the rotation base  30  causes the rotation axes R 1 , R 2  to rotate about the longitudinal axis C with respect to the housing  3 , thus changing the extending directions of the rotation axes R 1 , R 2 . This in turn changes the rotational directions of the pulley  35  (the directions denoted by the arrow Z 1  and the arrow Z 2  in  FIG. 5 ) and the rotational directions of the articulation control dial  20  (the directions denoted by the arrow T 1  and the arrow T 2  in  FIG. 5 ), thus changing the operational directions (the directions denoted by the arrow Q 1  and the arrow Q 2  in  FIG. 5 ) of the operation input to the articulation control dial  20 . However, the operational direction of the articulation control dial  20  intersects with (being substantially perpendicular to) the longitudinal axis C and intersects with (being substantially perpendicular to) the extending directions of the rotation axes R 1 , R 2 , regardless of the angular positions of the rotation base  30  and the articulation control dial  20  about the longitudinal axis C. 
         [0045]    As described above, according to the present embodiment, the sheath  5 , the end effector  7 , and the articulation control dial  20  rotate together about the longitudinal axis C in response to an operation input supplied through the rotation control knob  18 . Hence, if the angular position of the end effector  7  about the longitudinal axis C changes due to the rotation of the end effector  7 , then the angular position of the articulation control dial  20  about the longitudinal axis C changes according to the change in the angular position of the end effector  7 . Therefore, when an operation input is supplied through the rotation control knob  18 , the operational directions of the articulation control dial  20  (the directions denoted by the arrow Q 1  and the arrow Q 2  in  FIG. 5 ) change according to the changes in the articulation directions of the end effector  7  (the directions denoted by the arrow B 1  and the arrow B 2  in  FIG. 2 ). For example, from a state in which the articulation direction of the end effector  7  and the operational direction of the articulation control dial  20  are substantially parallel, the end effector  7  is rotated about the longitudinal axis C by an operation input through the rotation control knob  18 . At this time, the articulation control dial  20  rotates about the longitudinal axis C together with the end effector  7 , so that the state, in which the articulation direction of the end effector  7  and the operational direction of the articulation control dial  20  are substantially parallel, is maintained even when the angular position of the end effector  7  about the longitudinal axis C changes. In other words, according to the present embodiment, even when an operation input is supplied through the rotation control knob  18 , the end effector  7  and the articulation control dial  20  rotate together about the longitudinal axis C without changing the relative relationship between the articulation direction of the end effector  7  and the operational direction of the articulation control dial  20 . 
         [0046]    Further, according to the present embodiment, regardless of the angular position of the articulation control dial  20  about the longitudinal axis C, the longitudinal axis C of the sheath  5  passes the articulation control dial  20 . Hence, in the state in which the articulation control dial  20  is rotating about the longitudinal axis C together with the sheath  5  in response to the operation input supplied through the rotation control knob  18 , the articulation control dial  20  is located at the position where the longitudinal axis C of the sheath  5  passes. Therefore, even when the articulation control dial  20  rotates together with the sheath  5 , the position of the articulation control dial  20  on a plane perpendicular to the longitudinal axis C hardly changes. 
         [0047]    A description will now be given of the operation and effect of the medical treatment implement  1  according to the present embodiment. When performing a treatment by using the medical treatment implement  1 , the end effector  7  is inserted into a body cavity, such as an abdominal cavity. Then, the end effector  7  is brought to a treatment target. At this time, the end effector  7  is rotated about the longitudinal axis C by supplying an operation input through the rotation control knob  18  or the end effector  7  is articulated with respect to the sheath  5  by an operation input through the articulation control dial  20  so as to place the end effector  7  at a position that allows the treatment target to be easily gripped. Then, the treatment target is positioned between the pair of the gripping pieces  12 ,  13 , and the end effector  7  is closed by supplying an operation input through the lever  17 . Thus, the treatment target is held between the gripping pieces  12 ,  13 . In this state, an operation input is given through the control button  19 A or  19 B to supply energy to the end effector  7 , thereby treating the treatment target by using the energy (treatment energy). 
         [0048]    According to the present embodiment, the sheath  5 , the end effector  7 , and the articulation control dial  20  rotate together about the longitudinal axis C in response to an operation input supplied through the rotation control knob  18 . Hence, even when the angular position of the end effector  7  about the longitudinal axis C with respect to the housing  3  changes, the relative angular position of the articulation control dial  20  about the longitudinal axis C with respect to the sheath  5  and the end effector  7  remains unchanged. In other words, even when an operation input is given through the rotation control knob  18 , the end effector  7  and the articulation control dial  20  rotate together about the longitudinal axis C without changing the relative relationship between the articulation directions of the end effector  7  (the directions denoted by the arrow B 1  and the arrow B 2  in  FIG. 2 ) and the operational directions of the articulation control dial  20  (the directions denoted by the arrow Q 1  and the arrow Q 2  in  FIG. 5 ). This enables the operator to easily know the articulation direction of the end effector  7  regardless of the angular position of the end effector  7  about the longitudinal axis C. 
         [0049]    Further, in a state in which the housing  3  is held by one hand (e.g. the right hand), the palm is in contact with the grip  16  (the proximal end outer surface  3 B) from the proximal side, and the middle finger, the ring finger, and the little finger are placed on the lever  17 . Further, the forefinger is used to supply an operation input for rotating the rotation control knob  18  and to also supply an operation input to the control button  19 A or  19 B. According to the present embodiment, the articulation control dial  20 , which is the articulation operation input unit, is positioned more closely to the proximal side than the reference position X 1 , which is the position at which the sheath  5  (the pipe  10  and the rotation control knob  18 ) projects toward the distal side from the housing  3  (the housing main body  15 ). Hence, when the housing  3  is held as mentioned above, the articulation control dial  20  can be easily rotated thereby to allow an operation input to be easily given by a thumb through the articulation control dial  20 , regardless of the angular position of the end effector  7  about the longitudinal axis C. Thus, an operation input can be easily given using the articulation control dial  20  only by the hand (i.e. one hand) holding the housing  3 , independently of the angular position of the end effector  7  about the longitudinal axis C. 
         [0050]    Further, in the present embodiment, the articulation control dial  20  is positioned apart on the proximal side from the rotation control knob  18  connected to the distal side of the housing  3 . This arrangement makes it easier to enter an operation input through the articulation control dial  20  by the thumb when the housing  3  is being held as described above. Further, in the present embodiment, the articulation control dial  20  is installed to the installation outer surface  27  facing the proximal side in the housing  3 , and the installation outer surface  27  forms the proximal end outer surface  3 B of the housing  3 . This arrangement makes it easier to enter an operation input through the articulation control dial  20  by the thumb when the housing  3  is being held as described above. Further, the articulation control dial  20  and the rotation base  30  are installed to the proximal end outer surface  3 B of the housing  3 , thus properly securing the space for placing the movable member  22  and the space for providing the articulation wires  41 A,  41 B inside the housing  3 . 
         [0051]    Further, according to the present embodiment, in the state in which the articulation control dial  20  is rotating about the longitudinal axis C together with the sheath  5  in response to an operation input supplied through the rotation control knob  18 , the articulation control dial  20  is located at the position that the longitudinal axis C of the sheath  5  passes, and the position of the articulation control dial  20  on a plane perpendicular to the longitudinal axis C hardly changes. Since the position of the articulation control dial  20  on the plane perpendicular to the longitudinal axis C hardly changes, it is further easier to enter an operation input through the articulation control dial  20  independently of the angular position of the end effector  7  about the longitudinal axis C. 
         [0052]    As described above, the present embodiment can provide the medical treatment implement  1  that ensures ease of operation for articulating the end effector  7  with respect to the sheath  5  regardless of the angular position of the end effector  7  about the longitudinal axis C. 
         [0053]    The part of the rotation base  30  that projects from the housing  3  may be rotated about the longitudinal axis C by, for example, the thumb of the right hand thereby to rotate the sheath  5  and the end effector  7  about the longitudinal axis C with respect to the housing  3 . 
       Modification Example 
       [0054]    In a first modification example illustrated in  FIG. 6 , the distal end of a drive shaft  25  is connected to a plate member  42  formed of an elastic material, and the plate member  42  is connected to an end effector  7  (a second gripping piece  13 ). The plate member  42  is movable together with the drive shaft  25  along a longitudinal axis C with respect to a sheath  5 . Further, as the drive shaft  25  and the plate member  42  move together along the longitudinal axis C, the end effector  7  opens or closes as described above. In the present modification example, the position at which the drive shaft  25  is connected to the plate member  42  (the distal end of the drive shaft  25 ) is on the proximal side with respect to a pivot axis P 1  of the articulation operation of the end effector  7  with respect to the sheath  5  regardless of whether gripping pieces  12 ,  13  of the end effector  7  are opened or closed (i.e. the positions of the drive shaft  25  and the plate member  42  in a longitudinal axis C direction). In other words, regardless of whether the gripping pieces  12 ,  13  of the end effector  7  are opened or closed, the distal end of the drive shaft  25  is positioned at the proximal side with respect to an articulating joint of the end effector  7 . 
         [0055]    In the present modification example having the configuration described above, even when the end effector  7  articulates with respect to the sheath  5 , the hard drive shaft  25  will not be subjected to a large force, and the plate member  42  formed of an elastic material elastically deforms due to the force generated by the articulation operation of the end effector  7 . Therefore, the articulation movement of the end effector  7  is not impeded by the drive shaft  25 , thus enabling the end effector  7  to properly articulate with respect to the sheath  5 . 
         [0056]    Further, in a second modification example illustrated in  FIG. 7 , a pulley  35 , to which the proximal ends of articulation wires  41 A,  41 B are connected, is provided coaxially with an articulation control dial  20 , which is an articulation operation input unit. The pulley  35  is rotatable about a rotation axis R 1  together with the articulation control dial  20  with respect to a rotation base  30 . Hence, in the present modification example, the gears  28  and  37  described in the first embodiment are not provided. 
         [0057]    As with the first embodiment, in the present modification example, when a rotation control knob  18  is rotated about a longitudinal axis C, a driving force (rotational driving force) is transmitted to the rotation base  30  and the articulation control dial  20  through a movable member  22 . This causes the rotation base  30 , the articulation control dial  20 , the pulley  35 , and the articulation wires  41 A,  41 B to rotate about the longitudinal axis C together with a sheath  5  and an end effector  7  with respect to a housing  3 . As with the first embodiment, therefore, even when the angular position of the end effector  7  about the longitudinal axis C changes, the end effector  7  and the articulation control dial  20  rotate together about the longitudinal axis C without changing the relative relationship between the articulation direction of the end effector  7  and the operational directions of the articulation control dial  20 . 
         [0058]    In the present modification example, as the articulation control dial  20  rotates about the rotation axis R 1  with respect to the rotation base  30  in response to an operation input, the pulley  35  rotates about the rotation axis R 1  together with the articulation control dial  20  with respect to the rotation base  30 . This causes the articulation wires  41 A,  41 B to move along the longitudinal axis C with respect to the sheath  5 , and the end effector  7  to articulate with respect to the sheath  5  as described above. For example, when the articulation control dial  20  is moved to one side (the side denoted by an arrow Q 1  in  FIG. 7 ) of the operational direction by supplying an operation input, the articulation control dial  20  and the pulley  35  rotate to one side (the side denoted by an arrow T 1  in  FIG. 7 ) of the rotational direction. Thus, the articulation wire  41 B moves to the proximal side (to be tightened) while the articulation wire  41 A moves to the distal side (to be loosened), causing the end effector  7  to articulate to the side denoted by the arrow B 2  in  FIG. 2  of the articulation direction with respect to the sheath  5 . Meanwhile, if the articulation control dial  20  is rotated to the other side (to the side denoted by an arrow Q 2  in  FIG. 7 ) by an operation input, then the articulation control dial  20  and the pulley  35  rotate to the other side (to the side denoted by an arrow T 2  in  FIG. 7 ) of the rotational direction. Thus, the articulation wire  41 A moves to the proximal side while the articulation wire  41 B moves to the distal side, causing the end effector  7  to articulate to the side denoted by the arrow B 1  in  FIG. 2 ) with respect to the sheath  5 . 
         [0059]    Here, it is assumed that the articulation direction of the end effector  7  and the operational direction of the articulation control dial  20  are substantially parallel regardless of the angular position of the end effector  7  about the longitudinal axis C. In this case, according to the configuration of the first embodiment (the configuration illustrated in  FIG. 3  to  FIG. 5 ), the side of the operational direction of the articulation control dial  20  (the directions denoted by the arrow Q 1  and the arrow Q 2  in  FIG. 5 ) to which the articulation control dial  20  moves in response to an operation input is the same as the side of the articulation direction of the end effector  7  (the directions denoted by the arrow B 1  and the arrow B 2  in  FIG. 2 ) to which the end effector  7  articulates. In contrast to this, according to the configuration of the second modification example (the configuration illustrated in  FIG. 7 ), the side of the operational direction of the articulation control dial  20  (the directions denoted by an arrow Q 1  and an arrow Q 2  in  FIG. 7 ) to which the articulation control dial  20  moves in response to an operation input is opposite from the side of the articulation direction of the end effector  7  to which the end effector  7  is articulated. Hence, the relationship between the side to which the articulation control dial  20 , which is the articulation operation input unit, is moved (the side to which the articulation control dial  20  is operated) in response to an operation input, and the side to which the end effector  7  is articulated by the articulation operation is determined according to the configuration for transmitting an operational force generated by an operation input supplied through the articulation control dial  20  to the articulation wires  41 A,  41 B. Therefore, the relationship between the side to which the articulation control dial  20  is operated by an operation input and the side to which the end effector  7  is articulated by the articulation operation is determined by designing the configuration for transmitting the operational force from the articulation control dial  20  to the articulation wires  41 A,  41 B at the time of manufacturing the medical treatment implement  1 . 
         [0060]    Further, in a third modification example illustrated in  FIG. 8 , as the articulation operation input unit, an articulation control lever  50  is provided in place of the articulation control dial  20 . The articulation control lever  50  is installed to a rotation base  30  through the intermediary of a rack  51 . The articulation control lever  50  is movable together with the rack  51  in the operational directions (the directions denoted by an arrow Q′ 1  and an arrow Q′ 2  in  FIG. 8 ) of an operation input with respect to the rotation base  30 . A gear section (linear gear section)  52  is formed on the rack  51  along the operational directions of the articulation control lever  50 . As with the first embodiment, in the present modification example, a pulley  35  to which the proximal ends of articulation wires  41 A,  41 B are connected is rotatable about a rotation axis R 2  with respect to the rotation base  30 . In the present modification example, the pulley  35  has a gear section  53  formed over the whole circumference around the rotation axis R 2 , and the gear section  53  meshes with the gear section  52  of the rack  51 . 
         [0061]    As with the first embodiment, in the present modification example, as a rotation control knob  18  rotates about a longitudinal axis C, a driving force (rotational driving force) is transmitted to the rotation base  30  and the articulation control lever  50  through the intermediary of a movable member  22 . This causes the rotation base  30 , the articulation control lever  50 , the pulley  35 , and the articulation wires  41 A,  41 B to rotate about the longitudinal axis C together with a sheath  5  and an end effector  7  with respect to a housing  3 . Hence, as with the first embodiment, even when the angular position of the end effector  7  about the longitudinal axis C changes, the end effector  7  and the articulation control lever  50  rotate together about the longitudinal axis C without changing the relative relationship between the articulation direction of the end effector  7  and the operational direction of the articulation control lever  50 . In the present modification example, the operational direction of the articulation control lever  50  intersects with (being substantially perpendicular to) a longitudinal axis C direction and intersects with (being substantially perpendicular to) the extending direction of the rotation axis R 2  regardless of the angular positions of the rotation base  30  and the articulation control lever  50  about the longitudinal axis C. 
         [0062]    In the present modification example, as the articulation control lever  50  and the rack  51  move in the operational direction with respect to the rotation base  30  in response to an operation input, the pulley  35  rotates about the rotation axis R 2 . This causes the articulation wires  41 A,  41 B to move along the longitudinal axis C with respect to the sheath  5  and the end effector  7  to articulate with respect to the sheath  5  as described above. For example, when the articulation control lever  50  is moved to one side (the side denoted by the arrow Q′ 1  in  FIG. 8 ) of the operational direction by supplying an operation input, the pulley  35  rotates to one side (the side denoted by an arrow Z′ 1  in  FIG. 8 ) of the rotational direction. This in turn causes the articulation wire  41 A to move to the proximal side, the articulation wire  41 B to move to the distal side, and the end effector  7  to articulate with respect to the sheath  5  to the side denoted by an arrow B 1  in  FIG. 2 . Meanwhile, when the articulation control lever  50  is moved to the other side (the side denoted by the arrow Q′ 2  in  FIG. 8 ) of the operational direction by supplying an operation input, the pulley  35  rotates to the other side (the side denoted by an arrow Z′ 2  in  FIG. 8 ) of the rotational direction. This in turn causes the articulation wire  41 B to move to the proximal side, the articulation wire  41 A to move to the distal side, and the end effector  7  to articulate with respect to the sheath  5  to the side denoted by an arrow B 2  in  FIG. 2 . 
         [0063]    Further, in a fourth modification example illustrated in  FIG. 9 , a pinion gear  55  and rack gears  56 A,  56 B are provided in place of the pulley  35 . The pinion gear  55  is provided coaxially with an articulation control dial  20  and is rotatable about a rotation axis R 1  together with the articulation control dial  20  with respect to a rotation base  30 . Further, the rack gears  56 A,  56 B mesh with the pinion gear  55 , and each of the rack gears  56 A and  56 B has the proximal end of its corresponding articulation wire ( 41 A or  41 B) connected thereto. Each of the rack gears  56 A and  56 B is movable along a longitudinal axis C together with its corresponding articulation wire ( 41 A or  41 B). 
         [0064]    As with the first embodiment, in the present modification example, when a rotation control knob  18  rotates about the longitudinal axis C, the driving force (rotational driving force) is transmitted to the rotation base  30  and the articulation control dial  20  through the intermediary of a movable member  22 . This causes the rotation base  30 , the articulation control dial  20 , the pinion gear  55 , the rack gears  56 A,  56 B, and the articulation wires  41 A,  41 B to rotate about the longitudinal axis C together with a sheath  5  and an end effector  7  with respect to a housing  3 . Hence, as with the first embodiment, even when the angular position of the end effector  7  about the longitudinal axis C changes, the end effector  7  and the articulation control dial  20  rotate together about the longitudinal axis C without changing the relative relationship between the articulation direction of the end effector  7  and the operational direction of the articulation control dial  20 . 
         [0065]    In the present modification example, the articulation control dial  20  and the pinion gear  55  rotate about a rotation axis R 1  in response to an operation input. This causes each of the articulation wires  41 A and  41 B to move along the longitudinal axis C together with its corresponding rack gear ( 56 A or  56 B) and the end effector  7  to articulate with respect to the sheath  5  as described above. For example, when the articulation control dial  20  is moved to one side (the side denoted by an arrow Q 1  in  FIG. 9 ) of the operational direction by supplying an operation input, the articulation control dial  20  and the pinion gear  55  rotate to one side (the side denoted by an arrow T 1  in  FIG. 9 ) of the rotational direction. This in turn causes the articulation wire  41 A and the rack gear  56 A to move to the proximal side, the articulation wire  41 B and the rack gear  56 B to move to the distal side, and the end effector  7  to articulate with respect to the sheath  5  to the side denoted by the arrow B 1  in  FIG. 2 . Meanwhile, when the articulation control dial  20  is moved to the other side (the side denoted by an arrow Q 2  in  FIG. 9 ) of the operational direction by supplying an operation input, the articulation control dial  20  and the pinion gear  55  rotate to the other side (the side denoted by an arrow T 2  in  FIG. 9 ) of the rotational direction. This in turn causes the articulation wire  41 B and the rack gear  56 B to move to the proximal side, the articulation wire  41 A and the rack gear  56 A to move to the distal side, and the end effector  7  to articulate with respect to the sheath  5  to the side denoted by the arrow B 2  in  FIG. 2 . 
         [0066]    Further, in the embodiments and the like described above, the lever  17  is positioned at the distal side of the grip  16 . However, in a modification example, the lever  17  is provided on the proximal side of the grip  16 , and the lever  17  can be opened or closed with respect to the grip  16 . 
         [0067]    Further, in a fifth modification example illustrated in  FIG. 10  to  FIG. 12 , a rotation control knob  18  is installed to a housing  3  at a different position from that in the first embodiment. In the present modification example, the rotation control knob  18  is installed to an installation outer surface  27 , which forms a part of a proximal end outer surface  3 B of a housing  3 . Further, the rotation control knob  18  is provided by being attached to a rotation base  30  at the proximal end portion of the housing  3 . Hence, in the present modification example, the rotation control knob  18  is not made integral with a sheath  5  and not fixed to the sheath  5  (a pipe  10 ). However, in the present modification example also, a distal end outer surface  3 A of the housing  3  has an opening  21  formed at a reference position X 1 , and the sheath  5  projects toward the distal side from the reference position X 1  of the housing  3 , as with the foregoing embodiments. 
         [0068]    In the present modification example, the rotation control knob  18  is fixed to the outer rim of the rotation base  30 . Inside the housing  3 , the rotation base  30 , to which the rotation control knob  18  is fixed, is installed to a movable member  22  from the proximal side, and the sheath  5  is installed to the movable member  22  from the distal side. Thus, when the rotation control knob  18  rotates about a longitudinal axis C, the rotation base  30  integrally rotates, and the movable member  22  and the sheath  5  rotate about the longitudinal axis C. In the present modification example, the movable member  22  is movable along the longitudinal axis C with respect to the sheath  5 , the rotation control knob  18 , and the rotation base  30 . 
         [0069]    In the present modification example, the rotation control knob  18  can be operated by, for example, the thumb of a hand holding the grip  16 . Further, a groove may be formed in the surface of the rotation control knob  18  so as to make it easier for a finger to catch the rotation control knob  18 . 
         [0070]    Further, another modification example may include both a distal rotation control knob attached to a sheath  5 , as with the rotation control knob  18  in the first embodiment, and a proximal rotation control knob fixed to the outer rim of a rotation base  30 , as with the rotation control knob  18  in the fifth modification example. In this case, the sheath  5  can be rotated by operating the distal rotation control knob  18  by, for example, a thumb, or operating the proximal rotation control knob  18  by, for example, a forefinger. More specifically, when the distal rotation control knob  18  is rotated, the proximal rotation control knob  18  and the sheath  5  rotate about a longitudinal axis C together with a movable member  22 . Further, when the proximal rotation control knob  18  is rotated, the distal rotation control knob  18  and the sheath  5  rotate about the longitudinal axis C together with the movable member  22 . 
         [0071]    In the foregoing embodiments and the like, the medical treatment implement ( 1 ) has the holdable housing ( 3 ) and the sheath ( 5 ), which is extended along the longitudinal axis (C) from the proximal side toward the distal side and which is rotatable about the longitudinal axis (C) with respect to the housing ( 3 ). The sheath ( 5 ) is connected to the distal side of the housing ( 3 ) such that the sheath ( 5 ) projects from the reference position (X 1 ) of the housing ( 3 ) toward the distal side. The medical treatment implement ( 1 ) includes the end effector ( 7 ), which is attached to the distal side of the sheath ( 5 ) and which articulates with respect to the sheath ( 5 ), causing the angle of the sheath ( 5 ) with respect to the longitudinal axis (C) to change, and the drive members ( 41 A,  41 B), which are connected to the end effector ( 7 ) and which, when driven, cause the end effector ( 7 ) to articulate with respect to the sheath ( 5 ). Further, the medical treatment implement ( 1 ) includes the articulation control input units ( 20 ;  50 ), each of which drives the drive members ( 41 A,  41 B) in response to an operation input and rotates about the longitudinal axis (C) together with the sheath ( 5 ) with respect to the housing ( 3 ) when the sheath ( 5 ) rotates. Each of the articulation control input units ( 20 ;  50 ) is attached to the housing ( 3 ) at a position closer to the proximal side than the reference position (X 1 ) of the housing ( 3 ). 
         [0072]    The above has described the embodiments and the like. The present invention, however, is not limited to the foregoing embodiments and the like, and a variety of modifications can be obviously made without departing from the spirit of the present invention.