Patent Document

FIELD OF THE INVENTION 
       [0001]    The present invention relates to a medical manipulator by which an end effector can be inserted into the interior of a living body for enabling a treatment to be carried out on a treatment target. 
       BACKGROUND OF THE INVENTION 
       [0002]    In a surgical treatment, without performing a thoracotomy or a laparotomy with respect to a patient, small holes are opened in the body, forceps, scissors, or the like are introduced into the body through the holes, and a desired surgical treatment (a so-called endoscopic surgical procedure) is carried out on diseased biological tissue or the like in the body. Recently, in this type of treatment, in addition to forceps or scissors, a medical manipulator is used, which is capable of performing operations with a higher degree of freedom in the living body. 
         [0003]    For example, with the medical manipulator disclosed in Japanese Laid-Open Patent Publication No. 2011-072570, during the surgical treatment, an end effector, which is disposed on a distal end side of a shaft, is inserted into the living body. The end effector is constituted as a gripper that is capable of gripping a target object to be treated and then applying electrical energy to the target object to be treated. By transmitting an operating force from an operating element (main body portion) disposed on the proximal end side of the shaft, variations in posture (for example, a yawing operation to tilt the gripper in a direction differing from the axial direction of the shaft, a rolling operation to rotate the gripper about the axis of the shaft, etc.) or opening and closing operations of the gripper are carried out. 
         [0004]    In the case that a surgical treatment is carried out using the medical manipulator, a plurality of holes are opened in the abdomen or the like of a patient, and an endoscope (camera) and a forceps or the like are inserted into the body cavity, together with inserting a distal end (gripper) of the medical manipulator. Consequently, under observation of the camera, the gripper is delivered to the site of a living tissue (treatment object) in the body, and by a closing operation of the gripper, the living tissue is gripped while electrical current is applied to the living tissue. During delivery of the gripper or when a treatment on the living tissue is performed, based on the operating force transmitted from the main body portion, the state of the gripper (the posture or the opening/closing condition thereof) can freely be changed at locations in the living body. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention has been devised in relation to the above-described medical manipulator, and has the object of providing a medical manipulator, which enhances the operability of an end effector that carries out a treatment on a treatment target, whereby the treatment can be implemented efficiently and with improved accuracy. 
         [0006]    To accomplish the aforementioned objects, the present invention is characterized by a medical manipulator including a shaft, a distal end working unit provided on a distal end of the shaft and having an end effector configured to carry out a treatment on a treatment target, and a main body portion disposed on a proximal end of the shaft and configured to operate the end effector based on an input from a person. The distal end working unit includes a bending portion disposed between the end effector and the shaft and which causes the distal end working unit to bend in a direction that differs from an axial direction of the shaft, in accordance with an operating force in the bending direction that is transmitted from the main body portion, and a tube, which is disposed at a position overlapping with the bending portion and is capable of bending in following relation to the movement of the bending portion. The tube transmits a rotational operating force, which is transmitted from the main body portion, to the end effector, so as to enable the end effector to be rotated through an unlimited range of rotation. 
         [0007]    According to the above description, the tube that is disposed in a position overlapping with the bending portion bends in following relation with the movement of the bending portion. Therefore, for example, even in the case that the treatment target is located deeply inside the living body, the posture of the end effector can easily be changed, and the end effector can be delivered smoothly to the treatment target. Further, the tube delivers the operating force in the rotational direction to the end effector, and the end effector is capable of rotating through an unlimited range of rotation, whereby the posture of the end effector at the distal end side of the bending portion can freely be changed, and a precise treatment can be carried out by changing the orientation of the end effector any number of times to conform with the treatment target. More specifically, high operability for the end effector is obtained, and the procedure performed on the treatment target can be conducted efficiently and accurately. 
         [0008]    The bending portion may include a structure in which three or more rigid joint members are arrayed in the axial direction, and the adjacent joint members are connected to each other so as to bend mutually. Further, the tube may extend over a length that is longer than the axial length of the bending portion. 
         [0009]    In this manner, with a structure in which three or more joints are subjected to bending, the bending portion can be bent gently and gradually. Further, the tube, which extends a greater length than the bending portion, easily bends in following relation to the bending portion, so that even in a bent state, the operating force in the direction of rotation can be transferred smoothly to the end effector. 
         [0010]    The distal end working unit may transmit operating forces in a distal end direction and a proximal end direction, which are transferred from the main body portion, to the end effector through the tube. 
         [0011]    In this manner, by transferring operating forces in the distal end and proximal end directions, to the end effector through the tube, the end effector can be caused to carry out various operations by the operating forces in the distal end and proximal end directions. 
         [0012]    In this case, the end effector is a gripper in which first and second gripper members are opened and closed to grip the treatment target. The gripper can close the first and second gripper members by the operating force in the proximal end direction that is transmitted through the tube, and can open the first and second gripper members by the operating force in the distal end direction that is transmitted through the tube. 
         [0013]    In this manner, assuming a structure is provided in which the first and second gripper members are opened and closed by operating forces in the distal end and proximal end directions, the treatment target can easily be sandwiched and gripped between the gripper members, and a predetermined treatment can be performed efficiently. 
         [0014]    Furthermore, the distal end working unit may include an outer shell member connected to a distal end of the bending portion, and a retaining member, which retains the end effector under a condition in which at least a portion of the retaining member is accommodated in the interior of the outer shell member, and is rotated relatively with respect to the outer shell member by the rotational operating force from the tube. 
         [0015]    Consequently, since the tube and the retaining member can be rotated relatively with respect to the bending portion and the outer shell member, the end effector that is held on the retaining member can be rotated suitably. 
         [0016]    In this case, the outer shell member may include a groove that is engraved in a circumferential direction on an inner wall confronting an outer surface of the retaining member, and the retaining member may include a projection that is inserted rotatably in the groove. 
         [0017]    In this manner, by inserting the projection of the retaining member rotatably in the groove, rotation of the retaining member is guided by the groove, and therefore, the retaining member (i.e., the end effector) can be rotated more reliably. 
         [0018]    Further, plural coils may be disposed in the interior of the tube in an overlapping manner so as to surround a hollow portion that extends in the axial direction, and at least two coils among the plural coils may be wound in mutually different winding directions. 
         [0019]    In this manner, by arranging the two coils, which are wound in different winding directions, in the interior of the tube, the strength of the tube can be increased. As a result, the rotational operating forces from the shaft can be transferred smoothly to the end effector through the tube. 
         [0020]    According to the present invention, the operability of an end effector that carries out a treatment on a treatment target can be improved, whereby the treatment can be implemented efficiently and with improved accuracy. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a perspective view showing the overall structure of a medical manipulator according to an embodiment of the present invention; 
           [0022]      FIG. 2  is a perspective view showing an enlarged representation of main components of a distal end working unit of the manipulator of  FIG. 1 ; 
           [0023]      FIG. 3A  is a first schematic view for describing in outline an energizing operation of the manipulator of  FIG. 1 ; 
           [0024]      FIG. 3B  is a second schematic view for describing in outline the energizing operation of the manipulator of  FIG. 1 ; 
           [0025]      FIG. 4A  is a first schematic view for describing in outline a yawing operation of the manipulator of  FIG. 1 ; 
           [0026]      FIG. 4B  is a second schematic view for describing in outline the yawing operation of the manipulator of  FIG. 1 ; 
           [0027]      FIG. 5  is a schematic view for describing in outline a rolling operation of the manipulator of  FIG. 1 ; 
           [0028]      FIG. 6A  is a first schematic view for describing in outline an opening and closing operation of the manipulator of  FIG. 1 ; 
           [0029]      FIG. 6B  is a second schematic view for describing in outline the opening and closing operation of the manipulator of  FIG. 1 ; 
           [0030]      FIG. 7  is a partial exploded perspective view showing an enlarged representation of a distal end side of the manipulator of  FIG. 1 ; 
           [0031]      FIG. 8  is a partial exploded perspective view showing an enlarged representation of a bending portion of the manipulator of  FIG. 1 ; 
           [0032]      FIG. 9  is a partial exploded perspective view showing an enlarged representation of a handle of the manipulator of  FIG. 1 ; 
           [0033]      FIG. 10  is a schematic plan view for describing the yawing operation of the manipulator of  FIG. 1 ; 
           [0034]      FIG. 11  is a partial perspective view for describing the yawing operation of the manipulator of  FIG. 1 ; 
           [0035]      FIG. 12  is a partial perspective view for describing an assembled condition in the interior of the handle of  FIG. 1 ; 
           [0036]      FIG. 13A  is a side view showing main components of the bending portion of the manipulator of  FIG. 1 ; 
           [0037]      FIG. 13B  is a plan view showing main components of the bending portion of the manipulator; 
           [0038]      FIG. 13C  is a cross sectional view taken along line XIIIC-XIIIC of  FIG. 13B ; 
           [0039]      FIG. 14A  is a partial perspective view showing at an enlarged scale a joint member of  FIG. 13A ; 
           [0040]      FIG. 14B  is a partial perspective view showing at an enlarged scale an assembled condition of the joint members; 
           [0041]      FIG. 15  is a schematic side view for describing the rolling operation of the manipulator of  FIG. 1 ; 
           [0042]      FIG. 16  is a partial perspective view for describing an assembled condition in the interior of the handle of  FIG. 1 ; 
           [0043]      FIG. 17  is a perspective view, partially cut away, of main components of a distal end part of the manipulator of  FIG. 1 ; 
           [0044]      FIG. 18A  is a cross sectional plan view showing a distal end part of the manipulator of  FIG. 1 ; 
           [0045]      FIG. 18B  is a cross sectional side view showing a distal end part of the manipulator of  FIG. 1 ; 
           [0046]      FIG. 19  is a schematic perspective view for describing an opening and closing operation of the gripper of  FIG. 1 ; 
           [0047]      FIG. 20A  is a first side view for describing operations on the side of the handle of  FIG. 19 ; 
           [0048]      FIG. 20B  is a second side view for describing operations on the side of the handle of  FIG. 19 ; 
           [0049]      FIG. 21A  is a principal plan view showing the gripper of  FIG. 1 ; 
           [0050]      FIG. 21B  is a partial plan view showing an open state of the gripper; and 
           [0051]      FIG. 21C  is a partial plan view showing a closed state of the gripper. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0052]    Hereinafter, a preferred embodiment of a medical manipulator according to the present invention will be described in detail below with reference to the accompanying drawings. 
         [0053]      FIG. 1  is a perspective view showing the overall structure of the medical manipulator according to the present embodiment. The medical manipulator (hereinafter referred to simply as a “manipulator  10 ”) according to the present embodiment is used in an endoscopic surgical procedure, and is configured to carry out a predetermined process (e.g., cauterization by application of heat) by applying electrical energy to a living tissue that serves as a treatment target X. As a biological tissue that serves as the treatment target X on which the manipulator  10  performs a treatment, for example, tumors (lesions), muscles, blood vessels, or nerves, etc., may be cited. 
         [0054]    The end effector of the manipulator  10  is constituted as a gripper  12  (electrosurgical knife) that applies electrical energy to the treatment target X by gripping the treatment target X. In the interior of the manipulator  10 , various mechanisms are provided for implementing delivery and gripping (an energizing operation) of the gripper  12 . Below, a detailed description will be given concerning the manipulator  10 . 
         [0055]    As shown in  FIG. 1 , the manipulator  10  comprises a distal end working unit  14  having a gripper  12  for carrying out a surgical procedure end, and a handle  18  (main body portion) disposed on the proximal end side of the shaft  16 , and which operates the distal end working unit  14  based on an operation (input) from a person or user of the manipulator  10 . Further, a controller  20  is connected to the handle  18  of the manipulator  10  for supplying desired electrical power when the distal end working unit  14  is operated. In addition, a high frequency power source  22  for energizing (supplying high frequency voltage) to the gripper  12  is connected to the handle  18 . 
         [0056]    Upon use of the manipulator  10 , the handle  18  is gripped and operated by the user (an operator such as a doctor or the like), and a distal end side of the manipulator  10  (the distal end working unit  14  and the distal end side of the shaft  16 ) is inserted into the body of a patient. At this time, the user opens a small diameter hole at a predetermined position on the body surface of the patient, installs a trocar  24  together with injecting a carbon dioxide gas, and inserts the shaft  16  into the patient via the trocar  24 . Further, in a state in which the distal end side of the manipulator  10  is inserted into the body, while observations are made through an endoscope, variations in posture and opening and closing operations of the gripper  12  are carried out appropriately. Consequently, the gripper  12  is delivered to the site of the treatment target X, and a procedure is performed to supply electrical current to the treatment target X. 
         [0057]    The structure of the end effector is not limited to a gripper  12  that supplies current to the treatment target X, and various alternative structures may be adopted for the end effector. For example, as the end effector, there may be applied a scissors or a surgical knife (blade) for cutting living tissue. Further, the end effector may be constituted as a gripping device for gripping a medical device (forceps, needle, etc.), and a surgical procedure can be performed on the treatment target X by the medical device that is gripped. 
         [0058]    As shown in  FIG. 2 , variations in posture and opening and closing operations of the gripper  12  are implemented on a distal end working unit  14  on the distal end of the manipulator  10 . As changes in the posture of the gripper  12 , there may be cited a yawing operation by which the gripper  12  is tilted so as to curve in a lateral direction (yawing direction) with respect to an axis Os of the shaft  16 , and a rolling operation in which the gripper  12  is rotated about an axis Or of the gripper  12 . Naturally, the variations in posture of the gripper  12  are not limited to a yawing operation and a rolling operation. For example, a pitch operation may be performed in which the gripper  12  is tilted in a vertical direction (pitch direction) with respect to the axis Os of the shaft  16 . 
         [0059]    The gripper  12  is constituted from two gripper members (first gripper member  26 , second gripper member  28 ), which are held while being capable of opening and closing by a gripper retaining member  30 . Distal end parts of the first and second gripper members  26 ,  28  are subjected to an opening and closing operation about a vertically oriented axis Og of the gripper retaining member  30 . The proximal end side of the gripper retaining member  30  is inserted rotatably through a cylindrically shaped outer shell member  32 . A bending portion  34  (joint part) that carries out the yawing operation of the distal end working unit  14  is connected to the proximal end side of the outer shell member  32 . 
         [0060]    The bending portion  34  is constituted by juxtaposing in the axial direction a plurality of joint members  36  (five are shown in  FIG. 2 ), which are made of a hard material, for example, stainless steel (hereinbelow, a description will be given in which the letters A through E are appended to each of the respective joint members  36  in order from the distal end side). The adjacent joint members  36  are connected so as to be mutually rotatable about hinge members  38 . Further, concerning the joint members  36 , the joint member  36 A on the furthest most distal end side is connected in a bendable fashion to the outer shell member  32 , whereas the joint member  36 E on the furthest most proximal end side is connected and fixed to the distal end of the shaft  16 . In the present embodiment, although stainless steel is used as the material for the joint members  36 , the invention is not limited to this feature, insofar as the joint members  36  are excellent in durability and are capable of realizing the functions of the present invention. For example, a polyether ether ketone resin (PEEK) may be used. 
         [0061]    The yawing operation of the distal end working unit  14  is implemented by continuing to bend in a linked manner the five hinge members  38  about the operational fulcrum of the joint member  36 E. Stated otherwise, by the outer shell member  32  and the joint members  36 A through  36 D being inclined in a yawing direction at substantially the same angle, the gripper  12  and the gripper retaining member  30  on the distal end side of the bending portion  34  are tilted integrally. The movable range of the yawing operation of the bending portion  34  can be set appropriately. For example, if the movable range is set up to a range at which the roll axis Or of the gripper  12  becomes perpendicular to the axis Os of the shaft  16 , i.e., a range in which the gripper  12  can be tilted to the left and right, that is, tilted 180°, the facing orientation of the gripper  12  can be varied over a wide range within the body. 
         [0062]    On the other hand, the rolling operation of the distal end working unit  14  is carried out by rotating the gripper retaining member  30  relatively to the outer shell member  32 . Stated otherwise, the outer shell member  32  that is connected to the bending portion  34  is maintained in a fixed condition with respect to the direction of rotation, and the gripper retaining member  30  rotates with respect to the outer shell member  32 . Therefore, the gripper  12  and the gripper retaining member  30  rotate together in unison. Further, in the present embodiment, the movable range (range of rotation of the gripper  12 ) of the rolling operation is unlimited. 
         [0063]    Furthermore, the opening and closing operation of the gripper  12  is carried out by opening and closing the first and second gripper members  26 ,  28 , i.e., by having the distal end parts of the first and second gripper members  26 ,  28  approach toward (abut) and separate away from each other, in a state of being held by the gripper retaining member  30 . The opening and closing operation of the gripper  12  can be realized at a desired timing based on operations of the user, regardless of any change in the posture of the gripper  12 . 
         [0064]    In the present embodiment, the variation in posture (the yawing operation and the rolling operation) of the gripper  12  and the opening and closing operation of the gripper  12  are carried out based on operating forces that are transmitted from the shaft  16  to the distal end working unit  14 . 
         [0065]    Returning to  FIG. 1 , the shaft  16  that is connected to the distal end working unit  14  extends in a straight line over a predetermined length (e.g., 350 mm), and the handle  18  is connected to a proximal end portion of the shaft  16 . The shaft  16  includes a function to transfer operating forces from the handle  18  to the distal end working unit  14 . Further, during a surgical procedure, the proximal end side of the shaft  16  is exposed outside the body of the patient, and by manipulating the position and angle of the manipulator  10  (shaft  16 ) from the outside, the insertion angle and insertion amount of the distal end working unit  14  that is inserted in the body are changed. 
         [0066]    The handle  18  includes a handle main body  40  that is formed in the shape of a pistol for enabling easy gripping thereof by one hand of the user, and a drive unit  41  that is capable of being attached to and detached from an upper proximal end side portion of the handle main body  40 . The handle main body  40  includes a body portion  42 , which extends in the same direction as the axial direction of the shaft  16 , and a gripping unit  44  that extends downwardly from a lower side of the body portion  42 . 
         [0067]    The body portion  42  includes an internal space (not shown) having a comparatively large volume, and is provided with various mechanisms in the internal space for effecting operations (the yawing operation, the rolling operation, the opening and closing operation of the gripper  12 ) of the above-described distal end working unit  14 . On the other hand, a drive motor  46  (see  FIG. 11 ) that serves as a drive source for the yawing operation of the distal end working unit  14  is accommodated in the interior of the drive unit  41 . Further, the aforementioned controller  20  and the high frequency power source  22  are connected to the drive unit  41 . The controller  20  is connected to a non-illustrated power source, and includes a function to control rotary driving of the drive motor  46 . The high frequency power source  22  includes a function to supply power (high frequency voltage) to the gripper  12  based on manipulations performed by the user. 
         [0068]    Switches  48  (tilting operation unit) that carry out the yawing operation of the distal end working unit  14  are connected to side surfaces of the body portion  42 . Further, a rotating handle  50  (rolling operation unit) that carries out the rolling operation of the distal end working unit  14  is disposed in surrounding relation to an outer side of the shaft  16  at a portion where the shaft  16  is connected to the distal end side of the body portion  42 . Furthermore, a trigger  52  (opening and closing operation unit) that carries out the opening and closing operation of the gripper  12  is disposed in front of the gripping unit  44  on a lower side of the body portion  42 . 
         [0069]    The gripping unit  44  is formed somewhat more toward the distal end side than a middle region in the axial direction of the body portion  42 , and has a structure such that, in a condition in which a user grips the gripping unit  44  with one hand, the switches  48 , the rotating handle  50 , and the trigger  52  can be operated by a finger of the one hand that has gripped the gripping unit  44 . 
         [0070]    Operations of the distal end working unit  14  are carried out by the switches  48 , the rotating handle  50  and the trigger  52  being manipulated suitably by the user. The manipulator  10  according to the present embodiment performs a treatment on the treatment target X by mutually linking changes in posture (the yawing operation, the rolling operation) and the opening and closing operation of the gripper  12 , and an energizing operation based on the opening and closing operation of the gripper  12 . In the following description, to facilitate understanding of the invention, structures related to such operations will be described separately below in outline. 
         [0071]      FIG. 3A  is a first schematic view for describing in outline the energizing operation of the manipulator  10  of  FIG. 1 , and  FIG. 3B  is a second schematic view for describing in outline the energizing operation of the manipulator  10  of  FIG. 1 . First, a structure for enabling the energizing operation of the manipulator  10  will be described in outline. 
         [0072]    As described above, the manipulator  10  includes a function to supply electrical current to the treatment target X while the treatment target X is gripped by the gripper  12 . Therefore, the first and second gripper members  26 ,  28  are made from a metal material, and constitute electrodes (a minus electrode and a plus electrode) that supply current to the treatment target X. More specifically, the gripper  12  according to the present embodiment is a bipolar type of electrosurgical knife. Naturally, the invention is not limited to such a structure, and the end effector may be constituted as a monopolar type of electrosurgical knife. 
         [0073]    The first gripper member  26  and the second gripper member  28  are pivotally supported in an insulated state by a single fulcrum pin  54  (see  FIG. 2 ). When the operating force of the opening and closing operation is received, the distal end parts of the first and second gripper members  26 ,  28  are made to approach and separate away from one another about the fulcrum pin  54 . Therefore, although supply of current is interrupted in an open state in which the distal end parts of the first and second gripper members  26 ,  28  are separated, in a closed state in which the distal end parts of the first and second gripper members  26 ,  28  are brought into abutment (including a condition of an indirectly closed state upon sandwiching the treatment target X), the first and second gripper members  26 ,  28  become energized to thereby supply electrical current to the treatment target X. 
         [0074]    Respective metal members  56  (conductive paths) are connected electrically to the proximal end sides of the first and second gripper members  26 ,  28 . The metal members  56  (e.g., copper wires) of two polarities are covered by insulating members  58  at portions thereof that extend along the bending portion  34  and the shaft  16 , and the two insulating members  58  extend in the form of a single combined conductive line  60  as a result of being joined by welding or an adhesive. The conductive line  60  extends toward the proximal end together with the shaft  16 , and is inserted into the handle  18 . In the present embodiment, the conductive line  60  is arranged to pass through the axial center (axis Os) of the bending portion  34  and the shaft  16 . Consequently, since there is no need to provide separate wiring for the conductive line on the side surface of the distal end working unit  14  or the shaft  16 , entanglement of the conductive line by operating the distal end working unit  14  is avoided, and supply of current can suitably be performed. 
         [0075]    The conductive line  60  extends to the proximal end side of the shaft  16  that is inserted into the interior of the handle  18 , and the two metal members  56  in the conductive line  60  are connected respectively to a pair of cylindrical terminals  62  (rotating terminals) that are disposed on the shaft  16 . Contact terminals  64  are in contact respectively with the pair of cylindrical terminals  62 , and the contact terminals  64  are connected to the high frequency power source  22  externally of the handle  18 . 
         [0076]      FIG. 4A  is a first schematic view for describing in outline the yawing operation of the manipulator  10  of  FIG. 1 , and  FIG. 4B  is a second schematic view for describing in outline the yawing operation of the manipulator  10  of  FIG. 1 . Next, a structure for implementing the yawing operation will be described in outline. 
         [0077]    As described above, the yawing operation of the manipulator  10  is realized by the bending portion  34  that is connected to the distal end working unit  14 . On inner side surfaces in the width direction of the five joint members  36  that are arrayed in the axial direction, a pair of belts (a first belt  66  and a second belt  68 ) are inserted. The respective joint members  36  hold the first and second belts  66 ,  68  slidably. The distal end sides of the first and second belts  66 ,  68  are connected to the outer shell member  32 , and the proximal end sides thereof are connected to a pair of semicircular pipes (first semicircular pipe  70 , second semicircular pipe  72 : bending operation force transmitting members) that extend inside the shaft  16 . 
         [0078]    The first and second semicircular pipes  70 ,  72  are inserted through the interior of the shaft  16  extending to the handle  18 , and are connected to a pair of slide members (first slide member  74 , second slide member  76 ), which are disposed in the interior of the handle  18 . The first and second slide members  74 ,  76  are arranged at mutually confronting positions, with racks  78  being formed respectively on confronting surfaces thereof. Further, between the first and second slide members  74 ,  76 , a single pinion  80  (rotating member) is arranged in meshing relation with both of the racks  78 . The pinion  80  is connected mechanically to the drive motor  46  through a plurality of gears, which will be described later. 
         [0079]    With the manipulator  10 , which is constructed in this manner, for example, as shown in  FIG. 4B , when the pinion  80  is rotated clockwise by rotary driving of the drive motor  46 , the first slide member  74  undergoes sliding movement in the proximal end direction, and the second slide member  76  undergoes sliding movement in the distal end direction. Therefore, the first semicircular pipe  70 , which is connected to the first slide member  74 , also undergoes sliding movement in the proximal end direction, and the second semicircular pipe  72 , which is connected to the second slide member  76 , also undergoes sliding movement in the distal end direction. The operating forces of the first and second semicircular pipes  70 ,  72  are transmitted to the distal end working unit  14  (bending portion  34 ). 
         [0080]    More specifically, by the first belt  66  being moved relatively to the bending portion  34  in the proximal end direction, the first belt  66  in the bending portion  34  becomes shorter, and by the second belt  68  being moved relatively to the bending portion  34  in the distal end direction, the second belt  68  in the bending portion  34  becomes longer. As a result, the five joint members  36  tilt in conjunction to the side of the shortened first belt  66 , the outer shell member  32  that is connected to the distal end side of the joint members  36  is tilted, and the gripper  12  and the gripper retaining member  30  are made to move laterally (in the yawing direction) with respect to the axis Os of the shaft  16 . 
         [0081]      FIG. 5  is a schematic view for describing in outline the rolling operation of the manipulator  10  of  FIG. 1 . Next, a structure for implementing the rolling operation will be described in outline. 
         [0082]    As described above, the rolling operation of the manipulator  10  is carried out by rotating the gripper  12  and the gripper retaining member  30  relatively with respect to the outer shell member  32 . A rotatable hollow tube  82  is connected to the proximal end side of the gripper retaining member  30 , and the hollow tube  82  is inserted through the interior of the bending portion  34  (the five joint members  36 ). The hollow tube  82  is flexible and is capable of following the bending movement of the bending portion  34 , and is constructed as a torque tube, which is capable of rotating even if the hollow tube  82  is bent in following relation to the bending portion  34 . The conductive line  60  (see  FIG. 3A ) is inserted through the interior of the hollow tube  82 . The outer diameter of the hollow tube  82  preferably is 2.5 mm to 3.0 mm, and in the present embodiment, a description is given in which the outer diameter thereof is 2.7 mm. 
         [0083]    The shaft  16  that is connected to the bending portion  34  is constituted by a double tube structure, including an outer tube  84  that makes up the exterior and extends in the axial direction, and an inner tube  86  that is inserted through the interior of the outer tube  84 . The hollow tube  82  is connected to the inner tube  86  of the shaft  16 , and rotates by receiving an operating force (rotational torque) in the direction of rotation that is transmitted from the inner tube  86 . 
         [0084]    The proximal end side of the outer tube  84  is inserted into the handle  18 , and is connected fixedly at a distal end position of the handle  18 . On the other hand, the inner tube  86  extends toward the proximal end more so than the outer tube  84 , and is supported rotatably by a rotation mechanism  88  in the interior of the handle  18 . The rotation mechanism  88  includes a plurality of gears, and the inner tube  86  is connected mechanically through the plural gears to the rotating handle  50  that is disposed on the distal end side of the handle  18 . The rotating handle  50  is rotatable along the circumferential direction of the outer tube  84 . 
         [0085]    Accordingly, when the user manually performs a rotating operation on the rotating handle  50 , the rotational torque of the rotating handle  50  is transmitted to the interior of the handle  18  on the proximal end side, and the inner tube  86  is made to rotate through the rotation mechanism  88 . The operating force in the direction of rotation of the inner tube  86  is transmitted to the hollow tube  82 , and the hollow tube  82  rotates together with the inner tube  86 . As a result, the gripper retaining member  30  (gripper  12 ), which is connected to the distal end side of the hollow tube  82 , is rotated about the axis Or of the gripper  12 . In particular, in the manipulator  10  according to the present embodiment, the gripper  12 , the gripper retaining member  30 , the hollow tube  82 , and the inner tube  86  are arranged in a separated state with respect to the outer shell member  32 , the bending portion  34 , and the outer tube  84 , and are capable of being rotated through an unlimited range of rotation. Accordingly, a change in posture of the gripper  12  by the rolling operation can be carried out any number of times. 
         [0086]      FIG. 6A  is a first schematic view for describing in outline the opening and closing operation of the manipulator  10  of  FIG. 1 , and  FIG. 6B  is a second schematic view for describing in outline an opening and closing operation of the manipulator  10  of  FIG. 1 . Next, a structure for implementing the opening and closing operation will be described in outline. 
         [0087]    The opening and closing operation of the gripper  12  is realized by transmission of the operating force in the distal end and proximal end directions from the handle  18  with respect to the gripper  12 . The first and second gripper members  26 ,  28  comprise extension pieces  90  that extend backward obliquely toward the proximal end side beyond the fulcrum pin  54  about which the first and second gripper members  26 ,  28  pivot mutually. Long holes  92  are formed in the extension pieces  90 . A moving body  94 , which is capable of advancing and retracting (i.e., moving in the distal end and proximal end directions) relatively with respect to the gripper retaining member  30 , is arranged in the interior of the gripper retaining member  30 . A movable pin  96 , which is attached to the moving body  94 , is inserted into the long holes  92 . The relationship in which the gripper retaining member  30  and the moving body  94  are arranged is a relationship where, during the rolling operation, the gripper retaining member  30  and the moving body  94  move together, however, during the opening and closing operation, the gripper retaining member  30  does not move, and the moving body  94  makes advancing and retracting movements. Therefore, the movable pin  96  (moving body  94 ) approaches toward and separates away from the fulcrum pin  54  of the gripper retaining member  30 . 
         [0088]    The above-described hollow tube  82  is connected to the proximal end side of the moving body  94 . The moving body  94  undergoes advancing and retracting movements by transmission of the operating force in the distal end and proximal end directions from the hollow tube  82 . Further, the above-described inner tube  86  is connected to the proximal end side of the hollow tube  82 , and an advancing and retracting movement mechanism  98  in the handle  18  is connected to the proximal end side of the inner tube  86 . The advancing and retracting movement mechanism  98  includes a plurality of links, which mechanically connect the inner tube  86  with the trigger  52  that is disposed on the lower side of the handle  18 . 
         [0089]    For example, when the user performs a manual operation to pull the trigger  52 , the operating force of the trigger  52  is transmitted to the proximal end side within the handle  18 , and the inner tube  86  is moved in the direction of the proximal end through the advancing and retracting movement mechanism  98 . The operating force in the proximal end direction of the inner tube  86  is transmitted to the moving body  94  through the hollow tube  82 , whereby the moving body  94  undergoes a retracting movement. Conversely, if a pressing operation of the trigger  52  is performed, the moving body  94  undergoes an advancing movement. 
         [0090]    As shown in  FIG. 6A , in the position at which the moving body  94  is moved forward (i.e., in a state in which the movable pin  96  is located on the distal end side of the long holes  92 ), the extension pieces  90  of the first and second gripper members  26 ,  28  intersect at the location of the movable pin  96 . Therefore, the distal end portions of the first and second gripper members  26 ,  28  separate away from one another and are placed in an open condition. As shown in  FIG. 6B , at the position at which the moving body  94  is retracted (i.e., in a state in which the movable pin  96  is located on the proximal end side of the long holes  92 ), the long holes  92  of the first and second gripper members  26 ,  28  are guided, and the respective extension pieces  90  come into mutual proximity (overlap) with each other. Accordingly, the distal end portions of the first and second gripper members  26 ,  28  approach one another mutually and are placed in a closed condition. In this manner, at the gripper  12 , an opening and closing operation is realized by transmission of the operating force in the distal end and proximal end directions from the hollow tube  82 . 
         [0091]      FIG. 7  is a partial exploded perspective view showing an enlarged representation of a distal end side of the manipulator  10  of  FIG. 1 ,  FIG. 8  is a partial exploded perspective view showing an enlarged representation of the bending portion  34  of the manipulator  10  of  FIG. 1 , and  FIG. 9  is a partial exploded perspective view showing an enlarged representation of the handle  18  of the manipulator  10  of  FIG. 1 . Next, with reference to  FIGS. 7 through 9 , members that make up the manipulator  10  according to the present embodiment will be described in detail. 
         [0092]    The first and second gripper members  26 ,  28  that constitute the gripper  12  are of a shape that extends in the distal end direction while the distal end portions are curved downward, and serrated meshing teeth  100  are formed on mutually confronting surfaces thereof. The meshing teeth  100  of the first and second gripper members  26 ,  28  enmesh with one another in a closed state. Further, the extension pieces  90  of the first and second gripper members  26 ,  28  are formed in flat plate shapes having a predetermined plate thickness (e.g., 0.5 mm), which extend from proximal end portions of the meshing teeth  100 . Round holes  102  in which the fulcrum pin  54  is fitted are bored through the extension pieces  90  at portions near the distal ends thereof. The fulcrum pin  54  is supported by insulating rings  104 , which are fitted into the round holes  102 . Long holes  92  are bored through proximal end sides of the extension pieces  90 . A movable pin  96  is inserted through an insulating tube  106  in the long holes  92 . Further, the extension pieces  90  of the first and second gripper members  26 ,  28  are inserted respectively into gaps  108  on the distal end side of the gripper retaining member  30 . 
         [0093]    The gripper retaining member  30  is made up from a three-pronged retaining member side section  112  that extends toward the distal end such that plate-shaped retaining plates  110  branch in three prongs so as to form the gaps  108 , and an engagement tubular portion  114 , which extends toward the proximal end and joins with the proximal end side of the three-pronged retaining member side section  112 . Fulcrum pin holes  116  through which the fulcrum pin  54  is inserted are formed on distal end parts of the three retaining plates  110 , and movable pin long holes  118  through which the movable pin  96  is inserted are formed on a proximal end side of the fulcrum pin holes  116 . A projection  120 , which projects radially outward and extends in the circumferential direction, is disposed on an outer surface of the engagement tubular portion  114 . Further, within the three-pronged retaining member side section  112  and the engagement tubular portion  114 , a sliding space  122  through which the moving body  94  is inserted (see  FIG. 18A ) is formed in a continuous manner. 
         [0094]    In a condition in which the first and second gripper members  26 ,  28  are arranged in the gaps  108 , the fulcrum pin  54  is inserted through the fulcrum pin holes  116 , and the end of the fulcrum pin  54  is fixed by a washer  124 , whereby the first and second gripper members  26 ,  28  are pivotally supported. In a condition in which the first and second gripper members  26 ,  28  are fixed by the fulcrum pin  54 , and the moving body  94  has been inserted through the sliding space  122 , the movable pin  96  is inserted through the long holes  92  and the movable pin long holes  118 , and by fixing the end of the movable pin  96  through a washer  126 , the movable pin  96  is arranged so as to be capable of advancing and retracting with respect to the long holes  92  and the movable pin long holes  118 . 
         [0095]    Similar to the gripper retaining member  30 , the moving body  94  has a three-pronged moving body side section  132  that extends toward the distal end such that plate-shaped retaining plates  128  branch in three prongs so as to form gaps  130  having the same width as the gaps  108 , and an insertion part  134 , which extends toward the proximal end and joins with the proximal end side of the three-pronged moving body side section  132 . Movable pin round holes  136  are formed on distal end parts of the three retaining plates  128 . The movable pin  96  is inserted through the movable pin round holes  136 , whereby attachment with the moving body  94  is completed. Further, a cylindrical body  138  is inserted in the insertion part  134  of the moving body  94 . A retaining plate  128   a , which extends in the center among the three retaining plates  128  of the moving body  94 , is made of an insulating material. 
         [0096]    The cylindrical body  138  extends a predetermined length (e.g., 6 mm) in the axial direction, and a hollow space  140  is formed in the interior of the cylindrical body  138 . The insertion part  134  is inserted in a distal end portion of the cylindrical body  138 , and a first connector  142  is inserted in a proximal end portion of the cylindrical body  138 . 
         [0097]    The first connector  142  includes a flange  144  disposed at an intermediate location, a distal end connecting projection  146  that extends toward the distal end from the flange  144 , and a proximal end connecting projection  148  that extends toward the proximal end from the flange  144 . The distal end connecting projection  146  of the first connector  142  is inserted into the cylindrical body  138 , and the proximal end connecting projection  148  of the first connector  142  is inserted into the hollow tube  82 , thereby connecting the cylindrical body  138  and the hollow tube  82  to each other. In a state in which the hollow tube  82  (first connector  142 ) is connected thereto, the cylindrical body  138  is inserted into the interior of the outer shell member  32 . 
         [0098]    The outer shell member  32  is made up from a distal end side tubular portion  150  in which the engagement tubular portion  114  of the gripper retaining member  30  is inserted, and a proximal end side tubular portion  152  in which the cylindrical body  138  is inserted. The distal end side tubular portion  150  includes an arcuate piece  150   a  that is separable in half from one side. On an inner surface of the distal end side tubular portion  150  (including the arcuate piece  150   a ), a groove  154  having a predetermined width (e.g., 2 mm) is provided. In the inserted condition of the gripper retaining member  30 , the projection  120  thereof is inserted in engagement with the groove  154 . 
         [0099]    The cylindrical body  138 , the first connector  142 , and the distal end side of the hollow tube  82  are inserted into the proximal end side tubular portion  152 . At upper and lower positions of the proximal end side tubular portion  152 , outer shell member side hinge pieces  156  are formed, which project in the proximal end direction. The outer shell member side hinge pieces  156  are connected bendably to the bending portion  34  positioned on the proximal end side with respect to the hinge pieces  156 . Further, cutout portions  158 , which match substantially with the distal end shapes of the belts (first and second belts  66 ,  68 ), are formed as a pair on the outside surface of the proximal end side tubular portion  152 . The distal ends of the belts are connected and fixed in the cutout portions  158  by fixing pins  160 . 
         [0100]    As shown in  FIG. 8 , the distal end working unit  14  includes a bending portion  34  that carries out the yawing operation of the gripper  12  (see  FIG. 7 ) on a proximal end side with respect to the outer shell member  32 . Four of the joint members  36 A through  36 D from among the five joint members  36 A through  36 E that make up the bending portion  34  are each equipped with a center tubular portion  162  (tubular portion), which is formed in a tubular shape in a central region thereof, distal end hinge pieces  164 , which extend toward the distal end side from the center tubular portion  162 , and proximal end hinge pieces  166 , which extend toward the proximal end side from the center tubular portion  162 . The center tubular portion  162  includes a hollow part  162   a  (see  FIG. 14A ) in a central portion thereof that penetrates in the axial direction. 
         [0101]    The distal end hinge pieces  164  are formed to extend inwardly more than the proximal end hinge pieces  166 . Each of the adjacent joint members  36  are connected such that the distal end hinge pieces  164  and the proximal end hinge pieces  166  overlap one another. Further, hinge holes  168  are formed in both the distal end hinge pieces  164  and the proximal end hinge pieces  166 , and joint pins  170  are inserted in the hinge holes  168  in a state in which the distal end hinge pieces  164  and the proximal end hinge pieces  166  overlap. Consequently, the hinge members  38  are constructed such that the adjacent joint members  36  are mutually connected bendably about the joint pins  170 . Further, the distal end hinge pieces  164  of the joint member  36 A on the furthest most distal end side are connected in a bendable fashion to the outer shell member side hinge pieces  156  of the outer shell member  32 . 
         [0102]    On the other hand, although the joint member  36 E on the furthest most proximal end side includes the center tubular portion  162  and the distal end hinge pieces  164  in the same manner as the joint members  36 A through  36 D, the joint member  36 E is not provided with the proximal end hinge pieces  166  on the proximal end side of the center tubular portion  162 , and includes a fitting extension  172 , which is formed with an outer diameter matching substantially with the inner diameter of the outer tube  84 . The fitting extension  172  of the joint member  36 E is fitted into and fixed to the outer tube  84 . 
         [0103]    The flexible hollow tube  82  is inserted through the hollow parts  162   a  of the five joint members  36 . The hollow tube  82  is formed with a predetermined inner diameter (e.g., 1.5 mm), and includes a hollow portion  82   a  that penetrates through the hollow tube  82  in the axial direction. The first connector  142  is connected to the distal end of the hollow tube  82 , and a second connector  174  is connected to a proximal end of the hollow tube  82 . The second connector  174 , similar to the first connector  142 , includes a flange  176  disposed at an intermediate location, a distal end connecting projection  178  that extends toward the distal end from the flange  176 , and a proximal end connecting projection  180  that extends toward the proximal end from the flange  176 . The distal end connecting projection  178  of the second connector  174  is inserted into the hollow tube  82 , and the proximal end connecting projection  180  of the second connector  174  is inserted into the inner tube  86 , thereby connecting the hollow tube  82  and the inner tube  86  to each other. 
         [0104]    Further, the belts (the first and second belts  66 ,  68 ) are inserted through the bending portion  34  along inner side surfaces of the five joint members  36 . Reinforcing plates  182  are bonded to inner sides of the first and second belts  66 ,  68 , and the first and second belts  66 ,  68  extend in the axial direction. The distal ends of the first and second belts  66 ,  68  are connected to (the cutout portions  158  of) the outer shell member  32 , whereas the proximal ends thereof are connected to the first and second semicircular pipes  70 ,  72  that are arranged between the outer tube  84  and the inner tube  86 . The first and second belts  66 ,  68  are slidable with respect to the joint members  36 , so that the outer shell member  32  on the distal end side can be tilted in lateral directions responsive to the sliding amount of the first and second belts  66 ,  68 . 
         [0105]    The outer tube  84  and the inner tube  86  that make up the shaft  16 , and the first and second semicircular pipes  70 ,  72  that are disposed therebetween, extend in the proximal end direction and are inserted into the handle  18 . As shown in  FIG. 9 , the handle main body  40  of the handle  18  is constructed so as to be capable of being separated (into a right side casing  40   a  and a left side casing  40   b , see  FIG. 1 ) in the vertical direction (the left side casing  40   b  is omitted from illustration in  FIG. 9 ). Further, an insertion hole  42   a  for insertion therein of the shaft  16  is formed on the distal end surface of the handle main body  40 . 
         [0106]    A first bracket  200  to which the proximal end of the shaft  16  (outer tube  84 ) is connected, and a second bracket  202  that confronts the first bracket  200  are arranged in the interior space of the handle main body  40 . The first bracket  200  is formed in a bent plate-like shape having a distal end surface and a right side surface, and the second bracket  202  is formed in a bent plate-like shape having an upper surface and a left side surface. A shaft insertion pipe  204 , which extends in the distal end direction, is disposed on the distal end surface of the first bracket  200 , and the shaft  16  is inserted into the shaft insertion pipe  204  in a condition in which the outer tube  84 , the semicircular pipes, and the inner tube  86  overlap. Further, by insertion of the shaft insertion pipe  204  into a through hole  50   a  of the rotating handle  50 , the rotating handle  50  is mounted rotatably with respect to the first bracket  200  (i.e., the handle  18 ). 
         [0107]    The first and second slide members  74 ,  76  are arranged at positions near an upper portion between the first and second brackets  200 ,  202 . The first and second slide members  74 ,  76  are substantially T-shaped as viewed from the side, and have bar portions  206  that extend in the distal end and proximal end directions, and attachment parts  208  that extend downwardly from the bar portions  206 . The above-described racks  78  are disposed on confronting surfaces of the pair of bar portions  206 . The bar portions  206  are disposed slidably in supporting cutouts  210  that are formed in the first bracket  200 . A stopper  212 , which regulates a movement limit of the proximal end side of the first and second slide members  74 ,  76 , is disposed on the proximal end side of the first and second brackets  200 ,  202 . 
         [0108]    On the other hand, confronting surfaces on the lower end side of the pair of attachment parts  208  are formed in arcuate shapes, and are capable of coming into intimate contact with outer surfaces of the first and second semicircular pipes  70 ,  72 . Stated otherwise, the first semicircular pipe  70  is connected to the attachment part  208  of the first slide member  74 , and the second semicircular pipe  72  is connected to the attachment part  208  of the second slide member  76 . Consequently, the proximal end sides of the first and second semicircular pipes  70 ,  72  are supported by the first and second slide members  74 ,  76 , and the first and second semicircular pipes  70 ,  72  extend in the distal end direction between the outer tube  84  and the inner tube  86 . 
         [0109]    The pinion  80 , which is disposed on the racks  78  between the first and second slide members  74 ,  76 , is formed on the lower end of a pinion shaft  214 . The pinion shaft  214  extends upwardly and is inserted through a pinion hole  202   a  provided in an upper surface of the second bracket  202 . On the pinion shaft  214 , a driven bevel gear  216  is fitted at a position located above the pinion  80 . The driven bevel gear  216  is formed with a toothed surface on an upper side surface (inclined surface) thereof, and a toothed surface of a main drive bevel gear  218  is arranged in meshed engagement with respect to the toothed surface of the driven bevel gear  216 . The main drive bevel gear  218  is connected to the distal end of a motor gear pin  220 , and a motor-driven driven gear  222  is disposed on the proximal end of the motor gear pin  220 . 
         [0110]    In a state in which the drive unit  41  is attached to the handle main body  40 , the motor-driven driven gear  222  is made to mesh with a motor-driven main drive gear  224  that projects from the distal end surface of the drive unit  41 . The drive motor  46  (see  FIG. 11 ) is arranged in the interior of the drive unit  41 , and the motor-driven main drive gear  224  is driven rotatably by the drive motor  46 . By such a structure, based on the rotary drive from the drive motor  46 , the first and second slide members  74 ,  76  are made to move slidably in the distal end and proximal end directions, whereby the first and second semicircular pipes  70 ,  72  connected thereto are operated. 
         [0111]    Further, the above-described switches  48  are disposed respectively on the right side surface of the first bracket  200  and on the left side surface of the second bracket  202 . The switches  48  are exposed to the outside from windows  42   b  that are formed on side surfaces of the handle main body  40  (see  FIG. 1 ). Non-illustrated electrical circuits, which are capable of sensing the operating state of the switches  48 , are printed on outer side surfaces of the first and second brackets  200 ,  202  that are in contact with both ends of the switches  48 . Further, a second signal connector (not shown) is disposed in the interior of the handle  18 . The second signal connector is electrically connected to the aforementioned electrical circuits, and when the drive unit  41  is mounted, the second signal connector is connected to a first signal connector (not shown) of the drive unit  41 . The manipulator  10  is constructed such that, by the connections of the first and second signal connectors, power is supplied to the electrical circuits, and operating signals (voltage values), which are generated by operating the switches  48 , are transmitted to the external controller  20 . Based on the operating signals, the controller  20  supplies power (signals) for rotating the drive motor  46 . 
         [0112]    Incidentally, the inner tube  86 , which is covered by the first and second semicircular pipes  70 ,  72 , extends in the proximal end direction more than the attachment parts  208  of the first and second slide members  74 ,  76 . A rotary driven gear  226 , which constitutes a portion of the rotation mechanism  88 , and a sliding drive shaft  228  (rotating shaft member), which constitutes a portion of the advancing and retracting movement mechanism  98 , are mounted on a proximal end side surface of the inner tube  86 . 
         [0113]    The rotary driven gear  226  extends a predetermined axial length (e.g., 6 mm), and a toothed surface, which is formed on the outer side surface thereof, meshes with a toothed surface of a rotary main drive gear  230 , which is arranged on the lower side of the rotary driven gear  226 . The rotary main drive gear  230  is connected and fixed to the proximal end of a rotating pin  232 . The rotating pin  232  is axially supported rotatably by a retaining projection  234  that projects from the plate surface of the first bracket  200 . Further, a handle-driven gear  236  is formed on the distal end of the rotating pin  232 . The handle-driven gear  236  is arranged in front of the distal end surface of the first bracket  200 . A toothed surface of the handle-driven gear  236  is enmeshed with a toothed surface of a handle main drive gear  238 , which is disposed on the proximal end side of the rotating handle  50  and is arranged inside the body portion  42 . By constructing the rotation mechanism  88  in this manner, the inner tube  86  is made to rotate about its axis based on a rotating operation of the rotating handle  50 . 
         [0114]    On the other hand, the sliding drive shaft  228  that is mounted on the inner tube  86  includes a head part  240  that is expanded radially outward on the distal end side, and a shank part  242  that extends a predetermined length toward the proximal end side from the head part  240 . A recessed portion  244  (groove) is formed along the circumferential direction on an outer side surface of the head part  240 , and projecting portions  248  (protrusion) of a responsive member  246  (moving body), which is arranged on the lower side of the sliding drive shaft  228 , is inserted into the recessed portion  244 . 
         [0115]    The responsive member  246  is made up from a block body which is formed in an oval shape as viewed from the side, and a pair of arms  250  that extend from an upper portion of the block body. The projecting portions  248  are formed on inner side surfaces, respectively, of upper end sides of the pair of arms  250 . Further, on a side surface of the responsive member  246 , two holes (an upper side hole  246   a  and a lower side hole  246   b ) are formed. The upper side hole  246   a  is pivotally supported by a first support pin  252  that extends from the first bracket  200 . Accordingly, the responsive member  246  is capable of rotating about the upper side hole  246   a  (first support pin  252 ). On the other hand, a spring link  256  is connected to the lower side hole  246   b  through a first link shaft  254 . 
         [0116]    The spring link  256  includes a zigzag-shaped spring member  258  in a central portion, together with two holes (front side hole  256   a , rear side hole  256   b ) formed on both ends thereof. The aforementioned first link shaft  254  is inserted in the rear side hole  256   b , and a second link shaft  260  is inserted in the front side hole  256   a . The second link shaft  260  is connected to an upper end of the trigger  52 . 
         [0117]    The trigger  52  is constituted from an extending handle  262 , which extends downwardly in a bifurcated form, and a linkage  264 , which projects from an upper portion of the extending handle  262 , and in which two holes (link hole  264   a , support hole  264   b ) are formed to penetrate. The aforementioned second link shaft  260  is inserted into the link hole  264   a . On the other hand, the support hole  264   b  is pivotally supported on a second support pin  266  that extends from the first bracket  200 . Accordingly, the trigger  52  is capable of rotating about the support hole  264   b  (second support pin  266 ). By constructing the advancing and retracting movement mechanism  98  in this manner, the sliding drive shaft  228  is made to move in the distal end and proximal end directions, based on a pulling operation and a pushing operation of the trigger  52 . As a result, advancing and retracting movements of the inner tube  86  can be implemented. 
         [0118]    Further, a rotating part of a slip ring system  270  is disposed on the shank part  242  of the sliding drive shaft  228 . The slip ring system  270  is a mechanism to continuously establish an electrical connection between the high frequency power source  22  and the conductive line  60  (the two metal members  56 ) arranged inside the inner tube  86 , even while the inner tube  86  is being rotated by the rotation mechanism  88 . More specifically, a first resin tube  272 , a first cylindrical terminal  62   a , a second resin tube  274 , a second cylindrical terminal  62   b , an insulating washer  276 , and a nut  278  are mounted externally with respect to the shank part  242  of the sliding drive shaft  228 . The first cylindrical terminal  62   a  is mounted on an outer side surface of the first resin tube  272 , with one of the metal members  56  (e.g., a positive terminal) being connected to the interior thereof. The second cylindrical terminal  62   b  is mounted on an outer side surface of the second resin tube  274 , with the other of the metal members  56  (e.g., a negative terminal) being connected to the interior thereof. The first and second contact terminals  64   a ,  64   b  abut respectively against side surfaces of the first and second cylindrical terminals  62   a ,  62   b , and the first and second contact terminals  64   a ,  64   b  are connected to the high frequency power source  22 . Consequently, in the slip ring system  270 , the first and second contact terminals  64   a ,  64   b  continue to remain in abutment, even if the first and second cylindrical terminals  62   a ,  62   b  are rotating. Thus, the output from the high frequency power source  22  is supplied to the metal members  56 . 
         [0119]      FIG. 10  is a schematic plan view for describing the yawing operation of the manipulator  10  of  FIG. 1 ,  FIG. 11  is a partial perspective view for describing the yawing operation of the manipulator  10  of  FIG. 1 , and  FIG. 12  is a partial perspective view for describing an assembled condition in the interior of the handle  18  of  FIG. 1 . 
         [0120]    Next, a structure in relation to the yawing operation of the manipulator  10  according to the present embodiment will be described in greater detail. As shown in  FIGS. 9 and 10 , on the handle  18 , two switches  48  (right side switch  48   a , left side switch  48   b ) are mounted on opposite side surfaces of the handle main body  40 . Center portions of the right side and left side switches  48   a ,  48   b  are supported on the handle  18  (by the first and second brackets  200 ,  202 ), and a structure is provided such that both end portions (a distal end portion and a proximal end portion) thereof are displaced about the center portions in response to pushing operation of the switches by the user. The right side and left side switches  48   a ,  48   b  are structured to be capable of being handled by both left-handed and right-handed users. For example, in the case that the gripping unit  44  is gripped by the right hand, the right side switch  48   a  can be operated by the index finger of the right hand. 
         [0121]    The right side switch  48   a  is constituted such that, in the case that the proximal end side (A1 in  FIG. 10 ) thereof is pressed, the distal end working unit  14  undergoes a yawing operation in a rightward direction (Y1 direction), and in the case that the distal end side (A2 in  FIG. 10 ) thereof is pressed, the distal end working unit  14  undergoes a yawing operation in a leftward direction (Y2 direction). On the other hand, the left side switch  48   b  is constituted such that, in the case that the proximal end side (A2 in  FIG. 10 ) thereof is pressed, the distal end working unit  14  undergoes a yawing operation in a leftward direction (Y2 direction), and in the case that the distal end side (A1 in  FIG. 10 ) thereof is pressed, the distal end working unit  14  undergoes a yawing operation in a rightward direction (Y1 direction). Owing to such a structure, whichever switch, i.e., the right side switch  48   a  or the left side switch  48   b , the user operates, the feeling of operation of the switches  48  matches with the sense (viewpoint) of the user. 
         [0122]    Stated otherwise, the operating signals that are generated by operating the switches  48  are of two patterns, i.e., a yawing operation signal in the left direction and a yawing operation signal in the right direction, and the signals are transmitted to the controller  20  (see  FIG. 11 ). The controller  20  outputs, to the drive motor  46 , a drive signal based on the operating signal for controlling the rotational speed, the rotational direction, etc. of the drive motor  46 . Based on the drive signal from the controller  20 , rotation of the drive motor  46  is carried out in the form of a clockwise rotation or a counterclockwise rotation. The driving control of the drive motor  46  may adopt various configurations. For example, configurations may be adopted in which, corresponding to the pressing force applied to the switches  48 , the rotational speed of the drive motor  46  is varied, or the bending speed of the yawing operation is varied. 
         [0123]    As shown in  FIGS. 11 and 12 , the manipulator  10  is constructed such that, by attaching the drive unit  41  to the handle main body  40 , the motor-driven main drive gear  224  that is mounted on the distal end of the drive motor  46  meshes with the motor-driven driven gear  222  in the interior of the handle  18 . The motor gear pin  220 , which is equipped with the motor-driven driven gear  222 , is retained rotatably by a first support bar  280  and a second support bar  282 , which are erected upwardly from the proximal end side of the second bracket  202 . The first support bar  280  includes an upper end portion which extends in the direction of the distal end and holds an upper end of the pinion shaft  214 . The pinion shaft  214  is rotated by the driven bevel gear  216 , which abuts against the main drive bevel gear  218  that is disposed on the distal end of the motor gear pin  220 , so as to rotate the pinion  80  that is formed on the lower end of the driven bevel gear  216 . 
         [0124]    The pinion  80  is arranged in a space that is formed by assembly of the first and second brackets  200 ,  202 . The first and second slide members  74 ,  76  are disposed in confronting relation sandwiching the pinion  80 . The bar portions  206  of the first and second slide members  74 ,  76  are supported in the supporting cutouts  210  (see  FIG. 9 ) of the first bracket  200 . The first and second semicircular pipes  70 ,  72  are connected respectively to the attachment parts  208  that extend downwardly from the bar portions  206 . Therefore, when the pinion  80  is rotated in one direction, the first slide member  74  and the second slide member  76  slide mutually in opposite directions, accompanied by the first semicircular pipe  70  and the second semicircular pipe  72  also sliding mutually in opposite directions. Sliding of the first and second semicircular pipes  70 ,  72  in opposite directions is transferred through the shaft  16  to the distal end working unit  14  on the distal end side. 
         [0125]      FIG. 13A  is a side view showing main components of the bending portion  34  of the manipulator  10  of  FIG. 1 ,  FIG. 13B  is a plan view showing main components of the bending portion  34  of the manipulator  10 , and  FIG. 13C  is a cross sectional view taken along line XIIIC-XIIIC of  FIG. 13B .  FIG. 14A  is a partial perspective view showing at an enlarged scale one of the joint members  36  of  FIG. 13A , and  FIG. 14B  is a partial perspective view showing at an enlarged scale an assembled condition of the joint members  36 . 
         [0126]    As shown in  FIGS. 13A and 13B , with the bending portion  34 , the first and second belts  66 ,  68 , which are connected to the distal ends of the first and second semicircular pipes  70 ,  72 , are inserted through the five joint members  36 , and are connected by fixing pins  160  to the outer shell member  32  on the distal end side. During the yawing operation, by sliding movement of the first and second belts  66 ,  68  in opposite directions, since one of the belts becomes shorter and the other of the belts becomes longer, the bending portion  34  is subjected to a bending operation. For implementing the bending operation, a structure is provided in which the first and second belts  66 ,  68  slide along inner side surfaces of the joint members  36 . 
         [0127]    As shown in  FIG. 14A , guide members  283  that serve to guide the first and second belts  66 ,  68  are disposed in the center tubular portions  162  of the joint members  36  on an outer side of the hollow parts  162   a  of the center tubular portions  162 . The guide members  283  comprise belt spaces  286  (penetrating cavities) that penetrate in the axial direction through the center tubular portion  162 , and projecting walls  284  that act as separations between the hollow parts  162   a  and the belt spaces  286 . The projecting walls  284  are erected in the hollow parts  162   a  perpendicularly to the distal end and proximal end hinge pieces  164 ,  166 , which extend in pairs on upper and lower parts of the center tubular portion  162 . The first and second belts  66 ,  68  are mounted so as to be inserted through the belt spaces  286  that are separated by the projecting walls  284  (see  FIG. 14B ). 
         [0128]    On the other hand, the distal end hinge pieces  164  and the proximal end hinge pieces  166  are formed at positions shifted by 90° with respect to the belt spaces  286  through which the first and second belts  66 ,  68  are inserted. Accordingly, the distal end hinge pieces  164  and the proximal end hinge pieces  166  are bendably connected by the joint pins  170 , and the adjacent joint members  36  are easily bent about the joint pins  170  responsive to sliding of the first and second belts  66 ,  68 . Further, in the case that the first and second belts  66 ,  68  are slid (i.e., in the event that the bending portion  34  is subjected to bending), the first and second belts  66 ,  68  can avoid becoming separated from the inner side surfaces of the center tubular portions  162  by the projecting walls  284 , and corresponding to the sliding amount, the joint members  36  can be bent together in conjunction. 
         [0129]    Furthermore, arcuate surfaces  288  through which the hollow tube  82  can be inserted are formed on upper and lower inside surfaces of the joint members  36 . In the event that the joint members  36  are bent, the hollow tube  82  bends in following relation thereto as a result of being guided by the arcuate surfaces  288 . 
         [0130]    The hollow tube  82  is flexible and is capable of being bent in following relation to the bending movement of the bending portion  34 , and as shown in  FIG. 13C , a hollow portion  82   a  is formed therein having an inner diameter that enables insertion of the conductive line  60 . The second connector  174  is connected to the proximal end side of the hollow portion  82   a , and the first connector  142  is connected to the distal end side of the hollow portion  82   a.    
         [0131]    Further, a double coil (a first coil  290 , a second coil  292 ) is arranged in the interior of the hollow tube  82  to surround the hollow portion  82   a . The first and second coils  290 ,  292  extend axially in an overlapping manner in a state of being wound mutually in different (clockwise, counterclockwise) winding directions. Consequently, when the hollow tube  82  is rotated clockwise, the coil (e.g., the first coil  290 ) that is wound in the clockwise direction expands in diameter, and the coil (e.g., the second coil  292 ) that is wound in the counterclockwise direction is reduced in diameter. Therefore, the shape of the double coil overall is maintained. As a result, even if the hollow tube  82  is rotated in a state in which the hollow tube  82  is bent by the bending portion  34 , the rotational torque thereof can easily be transmitted to the distal end side (the gripper  12 ). 
         [0132]    By constructing the manipulator  10  to include the distal end working unit  14  and the handle  18 , as described above, the gripper  12  can be tilted in lateral directions by the yawing operation. For example, as shown in  FIG. 11 , in the event that the gripper  12  is to be tilted in a rightward direction, the user presses the proximal end A1 of the right side switch  48   a  (or the distal end A1 of the left side switch  48   b ) (see  FIG. 10 ), whereby an operating signal from the switch  48  is sent to the controller  20 . The controller  20  receives the operating signal and outputs, to the drive motor  46 , a predetermined drive signal (electric power), and then the controller  20  rotates the motor-driven main drive gear  224  of the drive motor  46  in a clockwise direction. As a result, the motor gear pin  220  (and the motor-driven driven gear  222 ) is rotated in a counterclockwise direction, and the driven bevel gear  216  (and the pinion shaft  214 ), which is enmeshed with the main drive bevel gear  218 , is rotated in a clockwise direction as viewed in plan. Accordingly, the pinion  80  is rotated clockwise, whereupon the first slide member  74  is made to slide in the proximal end direction, and the second slide member  76  is made to slide in the distal end direction. 
         [0133]    Accompanying movement of the first slide member  74  in the proximal end direction, the first semicircular pipe  70  and the first belt  66  also undergo sliding movement in the proximal end direction. Further, accompanying movement of the second slide member  76  in the distal end direction, the second semicircular pipe  72  and the second belt  68  also undergo sliding movement in the distal end direction. Accordingly, in the bending portion  34 , since the axial length of the first belt  66  becomes shorter, whereas the axial length of the second belt  68  becomes longer, the bending portion  34  undergoes a yawing operation and is bent on the side of the first belt  66 . As a result, the gripper  12 , which is disposed on the distal end side of the bending portion  34 , is changed to a rightward tilted posture. 
         [0134]    The bending portion  34  may be constructed such that, during bending of the bending portion  34 , the sliding amounts of the first and second belts  66 ,  68  are changed responsive to the bending direction. More specifically, in the case that the bending portion  34  is bent, the length of the belt (first belt  66 ) on the inside of the bending direction becomes shorter than the belt on the outside (second belt  68 ) by an amount that is more than necessary. For this reason, a structure may be provided in which, by interposing non-illustrated gears between the pinion  80  and the racks  78  of the first and second slide members  74 ,  76  without the pinion  80  meshing directly with the racks  78 , the sliding amount of the belt on the inside of the bending direction (i.e., the first belt  66  in the case of the right side, the second belt  68  in the case of the left side) can be reduced. 
         [0135]      FIG. 15  is a schematic side view for describing the rolling operation of the manipulator  10  of  FIG. 1 , and  FIG. 16  is a partial perspective view for describing an assembled condition in the interior of the handle  18  of  FIG. 1 . 
         [0136]    Next, a structure in relation to the rolling operation of the manipulator  10  according to the present embodiment will be described in greater detail. As shown in  FIG. 15 , by the rolling operation, the gripper  12  on the distal end of the manipulator  10  is rotated about the axis Or of the gripper  12 . In the present embodiment, the axis Or of the gripper  12  (end effector) is defined by the center axis of a portion that extends substantially in a straight line on the distal end side of the bending portion  34  (joint part). The axis Or is tilted in the yawing direction with respect to the axis Os of the shaft  16  (see  FIG. 4B ). 
         [0137]    The rolling operation is implemented by the user manually operating the rotating handle  50  that is mounted on the distal end of the handle  18 . The rotating handle  50  is a block shaped member having a width that is smaller than the width of the handle  18  as viewed in plan (see  FIG. 10 ). The shaft insertion pipe  204  of the first bracket  200  is inserted into the through hole  50   a  that is provided in the center thereof (see  FIG. 9 ). Further, plural blades  50   b  that make the rotating operation easier for the user are provided on side surfaces of the rotating handle  50 . 
         [0138]    As shown in  FIGS. 15 and 16 , a latch gear  294  and a handle main drive gear  238 , which rotates together with the rotating handle  50 , are disposed on the proximal end side of the rotating handle  50 . The latch gear  294  and the handle main drive gear  238  are disposed in a distal end part of an interior space of the handle  18 . The outer side surface of the latch gear  294  is formed in a wavelike shape (irregular surface) by arc-shaped valley portions  296 , and mountain portions  298  that bulge upwardly between the valley portions  296 . A latch piece  300  is configured to abut against the outer side surface of the latch gear  294 . 
         [0139]    The latch piece  300  includes a mounting portion  304 , which is attached to a mounting plate  302  that extends in the distal end direction from the second bracket  202 , and an elastic piece  306  that extends obliquely downward from the mounting portion  304  and is capable of swinging elastically with respect to the mounting portion  304  (see  FIG. 9 ). The lower end of the elastic piece  306  is formed in an arcuate shape that matches with the valley portions  296  of the latch gear  294 , and in a mounted state of the latch piece  300 , is in surface contact with the valley portions  296 . When the rotating handle  50  is rotated, the latch gear  294  also rotates, and by such rotation, the latch piece  300  (the elastic piece  306 ) swings elastically along the valley portions  296  and the mountain portions  298 . When the elastic piece  306  overcomes the mountain portions  298  and moves into the valley portions  296 , a positive displacement takes place due to the elastic force thereof, and the displacement of the latch piece  300  is transmitted as a tactile sensation to the user that operates the rotating handle  50 . Furthermore, along with displacement of the latch piece  300 , since operating noise is generated, the operational feeling of the rotating handle  50  can be recognized more strongly by the user. Consequently, the user can perform the rotating operation of the rotating handle  50  more intuitively. 
         [0140]    The handle main drive gear  238  rotates the rotating pin  232  (handle-driven gear  236 ) that is supported on the first bracket  200 . The handle-driven gear  236  is formed with a smaller outer diameter than the handle main drive gear  238 , and is rotated at a greater amount of rotation than the amount of rotation of the rotating handle  50 . The rotary main drive gear  230 , which is disposed on the proximal end side of the rotating pin  232 , rotates the rotary driven gear  226  that is fixed to the inner tube  86  of the shaft  16 , and the rotary driven gear  226  is rotated integrally with the inner tube  86 . 
         [0141]    Further, the sliding drive shaft  228  and the slip ring system  270  (excluding the first and second contact terminals  64   a ,  64   b ), which are mounted more on the proximal end side than the rotary driven gear  226 , rotate together with the inner tube  86 . The first and second contact terminals  64   a ,  64   b  abut elastically against the first and second cylindrical terminals  62   a ,  62   b , so as to remain in contact therewith even though the first and second cylindrical terminals  62   a ,  62   b  are rotating. Thus, steady electrical conduction is realized between the high frequency power source  22  and the conductive line  60  that is arranged in the interior of the inner tube  86 . 
         [0142]      FIG. 17  is a perspective view, partially cut away, of main components of a distal end part of the manipulator  10  of  FIG. 1 ,  FIG. 18A  is a cross sectional plan view showing a distal end part of the manipulator  10  of  FIG. 1 , and  FIG. 18B  is a cross sectional side view showing a distal end part of the manipulator  10  of  FIG. 1 . 
         [0143]    As shown in  FIG. 17 , the distal end working unit  14  is constituted such that the gripper  12  rotates in the circumferential direction on the distal end side of the bending portion  34 . More specifically, by connecting the outer shell member  32  to the distal end of the joint members  36  that constitute the bending portion  34 , a structure is provided in which the outer shell member  32  does not rotate. On the other hand, by transferring the rotational torque from the hollow tube  82  that is disposed in the interior of the bending portion  34 , a structure is provided in which the gripper  12  and the gripper retaining member  30  are rotated in the circumferential direction about the axis of the gripper  12 . 
         [0144]    More specifically, the hollow tube  82  is connected through the second connector  174  to the inner tube  86  of the shaft  16 , whereby the inner tube  86  rotates together with the hollow tube  82  (see  FIG. 13C ). As shown in  FIGS. 18A and 18B , the distal end of the hollow tube  82  is inserted into the engagement tubular portion  114  of the gripper retaining member  30 , and is fitted and connected to the proximal end connecting projection  148  of the first connector  142 . Further, the distal end connecting projection  146  of the first connector  142  is fitted into the cylindrical body  138 . 
         [0145]    The cylindrical body  138  is formed with an outer diameter that matches substantially with the inner diameter of the engagement tubular portion  114 . To the engagement tubular portion  114 , the rotational torque is transferred from the cylindrical body  138  that is connected to the hollow tube  82 . More specifically, when the hollow tube  82  is rotated and the rotational torque therefrom is transmitted, the first connector  142  and the cylindrical body  138  rotate together integrally, and the gripper retaining member  30  (the engagement tubular portion  114 ) is rotated accompanying rotation of the cylindrical body  138 . 
         [0146]    The insertion part  134  of the aforementioned moving body  94  is inserted in a distal end portion of the cylindrical body  138 . The retaining plate  128   a  at the center of the moving body  94  is made of an insulating material, and the retaining plate  128   a  extends to the proximal end side of the insertion part  134 , with welded portions  308  being provided on both upper and lower surfaces of the proximal end part thereof. The metal members  56  (metal wires), which are exposed from the distal end of the conductive line  60 , are welded by a welding material to the welded portions  308 . The conductive line  60  extends in the axial direction in the hollow portion  82   a  of the hollow tube  82  while a distal end part thereof is fixedly retained by the first connector  142 . By fitting the insertion part  134  in the cylindrical body  138 , the moving body  94  rotates along with the rotation of the cylindrical body  138 . Also, by transmitting rotation of the moving body  94  to the gripper retaining member  30 , the gripper retaining member  30  is rotated more smoothly. 
         [0147]    Because the first and second gripper members  26 ,  28  that make up the gripper  12  are supported by the gripper retaining member  30 , the first and second gripper members  26 ,  28  rotate together with rotation of the gripper retaining member  30 . More specifically, in the manipulator  10 , as shown in  FIG. 17 , the gripper  12 , the gripper retaining member  30 , and the hollow tube  82  are rotated about the axis Or of the gripper  12 . 
         [0148]    In particular, in the manipulator  10  according to the present embodiment, the rolling operation of the gripper  12  enables the gripper  12  to be rotated through a 360° unlimited range of rotation with respect to the axis Or of the gripper  12 . More specifically, the inner tube  86  is rotatable in an unlimited manner with respect to the outer tube  84 , and the hollow tube  82 , which is arranged at a position overlapping with the bending portion  34 , also is rotatable in an unlimited manner. Similarly, the gripper retaining member  30  (gripper  12 ), which is inserted in the outer shell member  32 , is rotatable in an unlimited manner. Further, since the conductive line  60  extends inside the hollow tube  82  and the inner tube  86 , the conductive line  60  rotates together with the hollow tube  82  and the inner tube  86 . At this time, conduction of electricity with the high frequency power source  22  at the proximal end side of the conductive line  60  is continued by the slip ring system  270 . 
         [0149]      FIG. 19  is a schematic perspective view for describing the opening and closing operation of the gripper  12  of  FIG. 1 ,  FIG. 20A  is a first side view for describing operations on the side of the handle  18  of  FIG. 19 , and  FIG. 20B  is a second side view for describing operations on the side of the handle  18  of  FIG. 19 . 
         [0150]    Next, a structure in relation to the opening and closing operation of the gripper  12  of the manipulator  10  according to the present embodiment will be described in greater detail. As shown in  FIG. 19 , by the opening and closing operation, distal end portions (serrated meshing teeth  100 ) of the first and second gripper members  26 ,  28  of the gripper  12  are made to approach and separate away from each other. The opening and closing operation is implemented by the user manually operating the trigger  52  of the handle  18 . 
         [0151]    As shown in  FIGS. 20A and 20B , the trigger  52  is arranged on the lower side of the rotating pin  232  that makes up the rotation mechanism  88 , and is supported swingably with respect to the first bracket  200  (handle  18 ). More specifically, the linkage  264  of the trigger  52  is supported by the second support pin  266  that extends from the first bracket  200 , and the extending handle  262  is operated in the distal end and proximal end directions about the second support pin  266 . 
         [0152]    The linkage  264  of the trigger  52  is connected to the advancing and retracting movement mechanism  98  that operates the inner tube  86 . More specifically, a distal end of the spring link  256  is connected through the second link shaft  260  to an upper portion (link hole  264   a ) above the insertion position of the second support pin  266  of the linkage  264 . The spring link  256  is arranged to extend in the proximal end direction, and the proximal end thereof is connected through the first link shaft  254  to a lower end portion (lower side hole  246   b ) of the responsive member  246 . The first support pin  252  that extends from the first bracket  200  is inserted into the upper side hole  246   a  of the responsive member  246 , and the projecting portion  248  (see  FIG. 9 ) of the pair of arms  250  that extend upwardly above the upper side hole  246   a  is inserted into the recessed portion  244  of the sliding drive shaft  228 . 
         [0153]    Consequently, when the extending handle  262  of the trigger  52  is pulled in the proximal end direction, the trigger  52  rotates about the second support pin  266 , and the upper end (the connection location of the spring link  256 ) of the linkage  264  is moved in the direction of the distal end. Along therewith, the spring link  256  also moves in the distal end direction, whereby the lower end of the responsive member  246  is made to move in the distal end direction. By the lower end moving in the distal end direction, the responsive member  246  rotates about the first support pin  252 , and the arms  250  on the upper end side are made to move in the direction of the proximal end. Accordingly, the sliding drive shaft  228  (recessed portion  244 ) is pressed by the projecting portion  248  and moves in the direction of the proximal end. As a result, the inner tube  86  moves in the proximal end direction together with the sliding drive shaft  228 , and the operating force in the proximal end direction is transferred through the shaft  16  to the distal end working unit  14  on the distal end side. 
         [0154]    Moreover, in the event that the extending handle  262  of the trigger  52  is operated by being pulled, the spring member  258  of the spring link  256  expands elastically, and serves to suppress movement of the inner tube  86  in the proximal end direction. Stated otherwise, the movement amount when the inner tube  86  is moved in the proximal end direction is limited to the degree at which the gripper  12  shifts to the closed state from the open state, and in the case that the trigger  52  is pulled beyond the above degree, the operating force is absorbed by elastic deformation of the spring member  258 . As a result, application of a large torque during the closing operation of the gripper  12  can be avoided. For example, movement of the inner tube  86  in the proximal end direction is of a degree that enables transitioning from the condition shown in  FIG. 20A  to the condition shown in  FIG. 20B . 
         [0155]    The axial length of the rotary driven gear  226  and the two cylindrical terminals  62 , which are mounted on the inner tube  86 , is set to be longer than the movement amount in advancing and retracting directions of the inner tube  86 . Therefore, even in the case that the trigger  52  is operated and the inner tube  86  is moved in the proximal end direction, the rotary main drive gear  230  can mesh continuously with the rotary driven gear  226 , and the first and second contact terminals  64   a ,  64   b  can remain in contact continuously with the first and second cylindrical terminals  62   a ,  62   b . Consequently, while the inner tube  86  undergoes rotation (i.e., while the rolling operation of the gripper  12  is carried out), opening and closing of the gripper  12  can be performed, and current can be supplied to energize the treatment target X. 
         [0156]      FIG. 21A  is a principal plan view showing the gripper  12  of  FIG. 1 ,  FIG. 21B  is a partial plan view showing an open state of the gripper  12 , and  FIG. 21C  is a partial plan view showing a closed state of the gripper  12 . The operating force that moves the inner tube  86  in the distal end and proximal end directions is transmitted to the hollow tube  82 , which is connected to the distal end of the inner tube  86 , whereby the hollow tube  82  is made to move in the distal end and proximal and directions. The cylindrical body  138  is connected through the first connector  142  to the distal end of the hollow tube  82 , and the cylindrical body  138  also is made to move together with the hollow tube  82 . 
         [0157]    The length in the axial direction of the hollow tube  82  is longer than the axial length of the bending portion  34  of the distal end working unit  14 , such that even if the hollow tube  82  is advanced and retracted, the hollow tube  82  is arranged to overlap with the bending portion  34  at all times. Accordingly, even if the bending portion  34  is subjected to bending as shown in  FIG. 11 , and the hollow tube  82  bends in following relation thereto, the hollow tube  82  can be advanced and retracted along the bend, and the operating force of the advancing and retracting movement can be transmitted to the cylindrical body  138  that is connected to the distal end side of the hollow tube  82 . 
         [0158]    As shown in  FIG. 18A , connecting pins  310   a ,  310   b , which project inwardly (into the hollow space  140 ) by a predetermined amount, are disposed on the distal end side and the proximal end side of the cylindrical body  138 . The first connector  142  is equipped with a first connector side engagement groove  312 , which is engraved in a circumferential direction in a root portion of the distal end connecting projection  146 . The proximal end side connecting pin  310   a  is inserted into the first connector side engagement groove  312 . Further, the moving body  94  is equipped with a moving body side engagement groove  314 , which is engraved in a circumferential direction in the insertion part  134  that projects in the proximal end direction. The distal end side connecting pin  310   b  is inserted into the moving body side engagement groove  314 . By this structure, the axial connections between the first connector  142 , the cylindrical body  138 , and the moving body  94  are reinforced by the connecting pins  310   a ,  310   b , and the operating force of the advancing and retracting movement, which is transmitted from the hollow tube  82 , is further transmitted reliably to the moving body through the cylindrical body  138 . 
         [0159]    On the other hand, the gripper retaining member  30  is placed in a condition in which the moving body  94  is arranged in the sliding space  122  thereof, and the gripper retaining member  30  remains fixed with respect to movements of the moving body  94  in the distal end and proximal end directions. More specifically, by engagement between the projection  120 , which is formed on the outer side surface of the engagement tubular portion  114 , and the groove  154 , which is formed on the inner side surface of the outer shell member  32 , the gripper retaining member  30  is placed in a fixed state in which back and forth movement thereof is restricted, in contrast to the advancing and retracting movements of the moving body  94 . 
         [0160]    In the moving body  94 , the first and second gripper members  26 ,  28  are sandwiched between the gaps  130  of (the three-pronged moving body side section  132  of) the distal end, and the movable pin  96 , which is inserted in the long holes  92  of the extension pieces  90 , is retained therein. As shown in  FIGS. 21A through 21C , in a condition in which the moving body  94  is positioned on the distal end side of the sliding space  122 , the movable pin  96  is moved to the distal end side of the long holes  92 , and the distal end portions of the first and second gripper members  26 ,  28  are separated and placed in an open condition. 
         [0161]    With respect to the open condition, when the inner tube  86  is moved in the proximal end direction by a pulling operation of the trigger  52 , an operating force in the proximal end direction is transmitted to the moving body  94  via the inner tube  86 , the second connector  174 , the hollow tube  82 , the first connector  142 , and the cylindrical body  138 . At this time, the first connector  142 , the cylindrical body  138 , and the moving body  94  are connected by the connecting pins  310   a ,  310   b , whereby the operating force in the proximal end direction is transferred smoothly. When the moving body  94  is moved in the proximal end direction, the movable pin  96  moves in the proximal end direction while guiding the long holes  92 , and based on the guiding of the long holes  92 , the distal end parts of the first and second gripper members  26 ,  28  are made to approach one another mutually, and a closed condition can be obtained. 
         [0162]    Further, as discussed above, in the close state of the gripper  12 , a current supplying condition is formed by the connection of the first and second gripper members  26 ,  28 , which are of different polarities. More specifically, in a state in which the treatment target X is sandwiched between the first and second gripper members  26 ,  28 , an output, which is supplied to the first and second gripper members  26 ,  28  through the conductive line  60  from the high frequency power source  22 , is supplied to the treatment target X, and a predetermined process (cauterization by application of heat, or the like) is performed thereon. 
         [0163]    In the foregoing manner, by means of the manipulator  10  according to the present embodiment, the hollow tube  82  that is disposed in a position overlapping with the bending portion  34  bends in following relation with the yawing operation of the bending portion  34 . Therefore, for example, even in the case that the treatment target X is located deeply inside the living body, the posture (inclination) of the gripper  12  can easily be changed, and the gripper  12  can be delivered smoothly to the treatment target X. 
         [0164]    Further, in the distal end working unit  14 , an operating force in the direction of rotation is transmitted to the gripper  12  by the hollow tube  82 , whereby the gripper  12  is rotated (subjected to a rolling operation) through an unlimited range of rotation. Therefore, the posture of the gripper  12  (i.e., a posture in the direction of rotation around the roll axis Or of the gripper  12 ) on the distal end side of the bending portion  34  can be changed freely, and the orientation of the gripper  12  can be changed any number of times to match with the treatment target X, and to enable an accurate treatment to be carried out on the treatment target X. 
         [0165]    Further, by constructing the bending portion  34  from the plural (five) joint members  36 , the bending portion  34  can be bent gently and gradually. Therefore, the hollow tube  82 , which is disposed at a position overlapping with the bending portion  34 , can easily follow the bending movement of the bending portion  34 . In addition, since the hollow tube  82  extends a greater length than the bending portion  34 , the operating force in the direction of rotation and the operating force in the distal end and proximal end directions, which are transmitted from the inner tube  86 , can be transferred smoothly beyond the bending portion  34  to the distal end side (gripper  12 ). 
         [0166]    Furthermore, in accordance with the operating forces in the distal end and proximal end directions that are transmitted through the hollow tube  82 , the opening and closing operation of the gripper  12  can easily be carried out. Consequently, the treatment target X can easily be gripped by the gripper  12 , and a predetermined procedure (energizing treatment) can be performed efficiently on the treatment target X. The operating forces in the distal end and proximal end directions may be used not only for carrying out an opening and closing operation of the gripper  12 , but also for carrying out, for example, an operation for moving, in the distal end and proximal end directions, the end effector as it is. 
         [0167]    Still further, by rotating the hollow tube  82  in a position overlapping with the bending portion  34 , and thereby rotating the gripper retaining member  30  that is connected to the hollow tube  82  relatively with respect to the outer shell member  32 , the gripper  12  that is held by the gripper retaining member  30  can be rotated suitably. At this time, the projection  120  of the gripper retaining member  30  is inserted rotatably in the groove  154  of the outer shell member  32 , whereby rotation of the gripper retaining member  30  is guided by the groove  154 . Thus, the gripper  12  can be rotated more smoothly, and the gripper  12  can be oriented in a desired posture. 
         [0168]    Further still, by arranging the first and second coils  290 ,  292 , which are wound in different winding directions, in the interior (hollow portion  82   a ) of the hollow tube  82 , the strength of the hollow tube  82  can be increased. More specifically, the rotational operating forces that are transmitted from the inner tube  86  can be transferred smoothly to the gripper  12  through the hollow tube  82 , the strength of which is increased and the shape of which is maintained. 
         [0169]    Further, by means of the manipulator  10  according to the present embodiment, even if the hollow tube  82 , which is disposed in a position overlapping with the bending portion  34 , is subjected to bending by the bending portion  34 , the operating force from the inner tube  86  is transferred to the distal end side (the gripper retaining member  30  and the moving body  94 ) relative to the bending portion  34 , while the hollow tube  82  remains in a bent condition. Thus, at the distal end side with respect to the bending portion  34 , variations in posture or opening and closing operations of the gripper  12  can easily be performed. 
         [0170]    In this case, by disposing the conductive line  60  in the hollow portion  82   a  of the hollow tube  82 , a conductive path leading to the gripper  12 , which is constituted as a bipolar type of electrosurgical knife, can easily be constructed, and electrical power can be supplied stably to the gripper  12 . 
         [0171]    For example, in the event that the operating force transmitted from the handle  18  is an operating force for rotating the inner tube  86 , the hollow tube  82  is rotated by the operating force, and the gripper  12 , which is connected to the distal end side of the hollow tube  82 , is made to undergo a rolling operation, whereby the gripper  12  can be made to face toward the treatment target X at a desired posture. At this time, by integral rotation of the conductive line  60  that is accommodated in the hollow tube  82 , disconnection between the gripper  12  and the conductive line  60  (conductive path) can reliably be prevented. 
         [0172]    Further, as described above, the slip ring system  270  is provided in the manipulator  10 . Specifically, a structure is enabled in which the contact terminals  64  are electrically connected to the cylindrical terminals  62  during times that the cylindrical terminals  62  are rotating and at rest. Consequently, even if the inner tube  86  is rotated in order for the gripper  12  to undergo the rolling operation, conduction of electricity with the high frequency power source  22  can continuously be maintained. Accordingly, even if the posture of the gripper  12  in the direction of rotation is changed, an electrical treatment can suitably be carried out. 
         [0173]    Further, for example, in the event that the operating force transmitted from the handle  18  is an operating force for moving the inner tube  86  in the distal end and proximal end directions, the hollow tube  82  is advanced and retracted together with movement of the inner tube  86 , whereby the gripper  12  can be opened and closed. At this time, by integral advancing and retracting movement of the conductive line  60  integrally with the hollow tube  82 , disconnection between the gripper  12  and the conductive line  60  (conductive path) can reliably be prevented. 
         [0174]    Furthermore, by means of the manipulator  10  according to the present embodiment, by constructing the bending portion  34  from the plural (five) joint members  36 , the hinge members  38 , and the first and second belts  66 ,  68 , the gripper  12  can easily be bent in a direction that differs from the axis Os of the shaft  16 . Further, through application of the first and second belts  66 ,  68 , the alignment of the plural joint members  36  can stably be maintained. For example, an operation to restore the bending portion  34  to its origin (where the bending portion  34  is aligned with the axial direction of the shaft  16 ) or the like can be performed quickly and accurately. Furthermore, in the case that the first and second belts  66 ,  68  cause the bending portion  34  to bend, the plural joint members  36  can smoothly be bent together in conjunction. The belts are not limited to the structure described above in which a pair (two) of such belts are disposed on the bending portion  34 , and one or three or more of such belts may be provided. 
         [0175]    In the case that a pair of belts (the first and second belts  66 ,  68 ) are provided, by relative operations of the first and second belts  66 ,  68 , the bending portion  34  can be bent smoothly. In other words, by carrying out an operation to move the first belt  66  in the proximal end direction and to move the second belt  68  oppositely in the distal end direction, the gripper  12  can easily be tilted to the side of the first belt  66 . 
         [0176]    Further, by providing the pinion  80  and the first and second slide members  74 ,  76  in the handle  18 , the rotational driving force of the pinion  80  can easily be converted into operating forces in the distal end and proximal end directions of the first and second slide members  74 ,  76 . In addition, the operating forces can be transmitted easily to the first and second belts  66 ,  68  through the first and second semicircular pipes  70 ,  72 . In this case, by controlling the rotational amount of the pinion  80 , the amount by which the bending portion  34  curves (i.e., the tilt angle of the gripper  12 ) can be changed freely. 
         [0177]    Furthermore, in the manipulator  10 , by the first and second belts  66 ,  68  being guided by the guide members  283 , the first and second belts  66 ,  68  move smoothly with respect to the center tubular portion  162 , and the operating force that moves the first and second belts  66 ,  68  in the distal end and proximal end directions can easily be transferred to the surrounding joint members  36 . At the time that the bending portion  34  is bent, outward bulging of the first and second belts  66 ,  68  can be suppressed. Furthermore, by disposing the guide members  283  on the outer side of the hollow parts  162   a , various transmission members that serve to operate the end effector (gripper  12 ) can appropriately be arranged in the hollow parts  162   a.    
         [0178]    Further, the guide members  283  are equipped with the projecting walls  284  that function as separations between the hollow parts  162   a  and the belt spaces  286 . Thus, since flexure of the first and second belts  66 ,  68  toward the inside (toward the centers of the joint members  36 ) is restricted by the projecting walls  284  at the time that the bending portion  34  is bent, the bending portion  34  can be bent more smoothly. 
         [0179]    Furthermore, by forming the arcuate surfaces  288  that are capable of contacting the hollow tube  82  on the inner side surface of the center tubular portions  162 , in the case that the bending portion  34  is bent, the hollow tube  82  that is inserted through the interior of the center tubular portions  162  can also easily be bent. 
         [0180]    Still further, with the manipulator  10  according to the present embodiment, by providing the rotation mechanism  88  and the advancing and retracting movement mechanism  98  in the interior of the handle  18 , the inner tube  86  can be moved in the distal end and proximal end directions, and the inner tube  86  can be rotated. Two types of operating forces of the inner tube  86  are transmitted to the gripper  12  of the distal end working unit  14  that is disposed on the distal end of the shaft  16 , whereby variations in posture and opening and closing operations of the gripper  12  can be carried out easily. 
         [0181]    In this case, by forming the length in the axial direction of at least one of the rotary driven gear  226  and the rotary main drive gear  230  of the rotation mechanism  88  to be longer than the movement amount of the inner tube  86  performed by the advancing and retracting movement mechanism  98 , even if the inner tube  86  is moved in the distal end and proximal end directions by the advancing and retracting movement mechanism  98 , the rotary driven gear  226  and the rotary main drive gear  230  can be kept in meshing engagement with each other at all times. Thus, the inner tube  86  can be rotated in a stable fashion. 
         [0182]    Further, by disposing the rotating handle  50  at a position in the vicinity of the handle  18 , in a state in which the user of the manipulator  10  has gripped the handle  18 , the user can easily manipulate the rotating handle  50 , which is in such a nearby position. Further, by forming the rotating handle  50  to be narrower than the width of the handle  18 , in the case that multiple medical devices (a forceps, a manipulator  10 , etc.) are used during a procedure, interference of the rotating handle  50  with such medical devices can be reduced. 
         [0183]    Furthermore, by providing the latch gear  294  that rotates accompanying rotation of the rotating handle  50  and the latch piece  300  that abuts elastically against the latch gear  294 , when the rotating handle  50  is operated, a latching sensation can be imparted to the user. Consequently, the user can recognize intuitively the amount of rotation of the rotating handle  50 , and can easily adjust the rotation of the inner tube  86 . 
         [0184]    Still further, in the advancing and retracting movement mechanism  98 , based on rotational operations of the responsive member  246 , the projecting portion  248  is displaced in the distal end and proximal end directions, and the sliding drive shaft  228  including the recessed portion  244  in which the projecting portion  248  is inserted also is displaced in the distal end and proximal end directions. Accordingly, the inner tube  86  on which the sliding drive shaft  228  is installed can move smoothly in the distal end and proximal end directions. Further, since the recessed portion  244  is formed in the circumferential direction, the sliding drive shaft  228  can rotate relatively with respect to the projecting portion  248 , and with a simple structure, rotation of the inner tube  86  can be allowed. 
         [0185]    More specifically, with the manipulator  10  according to the present embodiment, high operability of the gripper  12  that is inserted in the interior of the living body can be obtained, and the procedure performed on the treatment target X can be conducted efficiently and accurately. 
         [0186]    Although a certain preferred embodiment of the present invention has been shown and described in detail above, it should be understood that the present invention is not limited to the above embodiment and various changes and modifications may be made to the embodiment without departing from the scope of the invention as set forth in the appended claims. For example, in the above-described manipulator  10 , a structure is provided in which only the yawing operation is made to operate electrically (through the drive motor  46 ). However, the invention is not limited to this feature. More specifically, in the manipulator  10 , among the yawing operation, the rolling operation, and the opening and closing operation, any one or two or more of these operations can be constituted as an electrically driven operation, or alternatively the yawing operation, the rolling operation, and the opening and closing operation can all be constituted as manually driven operations.

Technology Category: 1