Abstract:
A switch mechanism for a medical manipulator, the switch mechanism including a moveable switching operation part, moving-side contacts provided to the switching operation part, and fixed-side contacts capable of contacting the moving-side contacts. At least the electrical-contact sections of the moving-side contacts and of the fixed-side contacts are formed from a corrosion-resistant material.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a medical manipulator equipped with a switch mechanism. 
       BACKGROUND OF THE INVENTION 
       [0002]    In an endoscopic surgical operation (also referred to as “laparoscopic surgery”), one or a plurality of holes are punctured in the abdomen or the like of a patient, and trocars (cylindrical instruments) are inserted through the holes. Thereafter, a laparoscope (camera) and a plurality of forceps are inserted into the body cavity via the one or more trocars. Grippers for gripping biological tissue, scissors, or blades of an electrosurgical scalpel are mounted to the distal end of the forceps as an end effector. 
         [0003]    If the laparoscope and the forceps are inserted into the body cavity, an operator operates the forceps while viewing a state of the inner portion of the abdominal cavity, which is shown on a monitor that is connected to the laparoscope. Since the surgical procedure does not require a laparotomy, the burden on the patient is reduced, which reduces the number of days for postoperative recovery and leaving the hospital. For this reason, the fields that such an operative method can be applied to are expected to expand. 
         [0004]    Other than typical forceps that are not provided with joints at distal end portions thereof, as forceps that are inserted through a trocar, forceps referred to as a medical manipulator have been developed that are provided with joints at distal end portions and which can carry out a rolling operation or a tilting operation of an end effector (for example, refer to Japanese Patent No. 4391762). In accordance with such a medical manipulator, a high degree of operational freedom is facilitated in the body cavity, manual procedures are made easy, and thus there are a large number of medical cases to which the medical manipulator may be applied. 
         [0005]    Further, with the aim of improving operability and facilitating manipulation, a medical manipulator has been proposed that carries out a portion or all of the operations of a distal end working unit by a drive source (motor) (see, for example, Japanese Laid-Open Patent Publication No. 2008-104854). In this type of medical manipulator, a switch operating member is provided on the handle. When the switch operating member is operated, a drive source is driven corresponding to the operating state of the switch operating member, and a distal end working unit is operated accordingly. 
       SUMMARY OF THE INVENTION 
       [0006]    Incidentally, after use of the medical manipulator, normally, a sterilization process is performed for cleaning and preparation for a next use of the medical manipulator. In the case of sterilization in which steam is used (autoclave sterilization, etc.), the switch mechanism including a switch operating member is exposed to water vapor. Accordingly, concerning the switch structure provided in the medical manipulator, it is desirable for the structure to be capable of withstanding the sterilization treatment in which steam is used. 
         [0007]    The present invention has been devised while taking into consideration the aforementioned problems, and has the object of providing a medical manipulator equipped with a switch mechanism that can withstand a sterilization treatment in which steam is used. 
         [0008]    For achieving the aforementioned object, the present invention is characterized by a medical manipulator equipped with a switch mechanism, in which the switch mechanism includes a movable switch operating member, a movable-side contact portion disposed on the switch operating member, and a fixed-side contact portion, which is capable of abutting against the movable-side contact portion, and wherein at least electrical contact portions of the movable-side contact portion and the fixed-side contact portion are formed from a corrosion-resistant material. 
         [0009]    According to the above configuration, in the switch mechanism, at least the electrical contact portions of the movable-side contact portion and the fixed-side contact portion are constituted from a corrosion-resistant material. For this reason, even if subjected to a sterilization treatment (autoclave sterilization, etc.) in which steam is used, it is unlikely for an oxide layer to be formed on the movable-side contact portion and the fixed-side contact portion, and conductivity can be maintained. Consequently, according to the present invention, a medical manipulator can be offered, which is equipped with a switch mechanism that can withstand a sterilization treatment in which steam is used. 
         [0010]    In this case, at a time of contact, the movable-side contact portion and the fixed-side contact portion rub against each other at contact locations therebetween. In accordance with such a configuration, even if an oxide layer is generated on each of contact points between the movable-side contact portion and the first and second fixed-side contact portions, the movable-side contact portion and the fixed-side contact portion rub against each other, and at the portions subjected to such mutual rubbing, an effect (refreshing effect) by which the electrical contact portions are activated can be obtained. Consequently, even if an oxide layer occurs or foreign matter is deposited or adhered thereon as a result of performing a sterilization treatment using steam, the electrical connection can suitably be assured as a result of the refreshing effect. 
         [0011]    When the fixed-side contact portion comes into contact with the movable-side contact portion, a contact region of the fixed-side contact portion with the movable-side contact portion may be capable of being displaced elastically. According to such a structure, when the movable-side contact portion is placed in contact with the fixed-side contact portion, the fixed-side contact portion is pressed and displaced elastically by the movable-side contact portion, and at this time, mutual rubbing takes place at the contact regions. Thus, with a simple structure, the aforementioned refreshing effect can be obtained. 
         [0012]    The fixed-side contact portion may be constituted as an elastically deformable plate-shaped body. With this configuration, in the fixed-side contact portion, since the elastic displacement function and the conductive element are integrated as a single member, the structure is simplified. 
         [0013]    Further, in the medical manipulator, when the movable-side contact portion comes into contact with the fixed-side contact portion, a contact region of the movable-side contact portion with the fixed-side contact portion may be capable of being displaced elastically. According to such a structure, when the movable-side contact portion is placed in contact with the fixed-side contact portion, the movable-side contact portion is pressed and displaced elastically by the fixed-side contact portion, and at this time, mutual rubbing takes place at the contact regions. Thus, with a simple structure, the aforementioned refreshing effect can be obtained. 
         [0014]    The movable-side contact portion may be constituted as an elastically deformable plate-shaped body. With this configuration, in the movable-side contact portion, since the spring element and the electrically conductive element are integrated into a single member, the structure is simplified. 
         [0015]    In the medical manipulator, the fixed-side contact portion may include a first fixed-side contact portion that abuts against the movable-side contact portion when the switch operating member is operated in a first direction from a neutral position, and a second fixed-side contact portion that abuts against the movable-side contact portion when the switch operating member is operated in a second direction opposite to the first direction from the neutral position. According to this configuration, since a two-way operation can be manipulated by switching the contact state between the movable-side contact portion, the first fixed-side contact portion, and the second fixed-side contact portion, the configuration serves as a suitable switching mechanism for the medical manipulator. 
         [0016]    The medical manipulator may contain a manipulator main body including a handle, and a drive unit that is capable of attachment and detachment with respect to the handle, and which includes a drive source. In this case, the switch mechanism may be disposed in the handle. According to this structure, since the drive source is provided on the side of the drive unit, there is no need to provide electronic devices, which are susceptible to moisture, in the manipulator main body. Accordingly, a sterilization treatment in which steam is used can suitably be performed on the manipulator main body. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  is a perspective view with partial omission of a medical manipulator according to an embodiment of the present invention; 
           [0018]      FIG. 2  is a perspective view of a drive unit; 
           [0019]      FIG. 3  is a perspective view showing the arrangement of a handle-side terminal member; 
           [0020]      FIG. 4  is a perspective view, as seen obliquely from below, of the drive unit; 
           [0021]      FIG. 5  is a perspective view of a switch mechanism in the medical manipulator illustrated in  FIG. 1 ; 
           [0022]      FIG. 6  is an exploded perspective view of the switch mechanism shown in  FIG. 5 ; 
           [0023]      FIG. 7  is a cross-sectional view of the switch mechanism taken along line VII-VII of  FIG. 5 ; 
           [0024]      FIG. 8  is a cross-sectional view of the switch mechanism in a state in which a rolling switch is operated in an A direction; 
           [0025]      FIG. 9  is a perspective view of the switch mechanism including a modification of the rolling switch; 
           [0026]      FIG. 10  is a perspective view of a medical manipulator according to another embodiment of the present invention; 
           [0027]      FIG. 11  is a perspective view of a switch mechanism of the medical manipulator illustrated in  FIG. 10 ; 
           [0028]      FIG. 12  is an exploded perspective view of the switch mechanism shown in  FIG. 11 ; 
           [0029]      FIG. 13  is a cross-sectional view of the switch mechanism taken along line XIII-XIII of  FIG. 11 ; 
           [0030]      FIG. 14  is a cross-sectional view of the switch mechanism in a state in which a tilting switch is operated in a C direction; 
           [0031]      FIG. 15A  is a view showing another structural example for returning the tilting switch to a neutral position; and 
           [0032]      FIG. 15B  is a view showing a condition in which the tilting switch shown in  FIG. 15A  has been operated. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0033]    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. 
         [0034]      FIG. 1  is a perspective view with partial omission of a medical manipulator  10 A (hereinafter referred to in abbreviated form as a “manipulator  10 A”) according to an embodiment of the present invention. The manipulator  10 A is a medical device that grasps a needle, a thread, or a part of the living body or touches the living body using a gripper  12  (end effector) provided at the distal end thereof, and carries out a predetermined treatment. 
         [0035]    The manipulator  10 A comprises a handle  14  on which a plurality of input operating members are provided, a shaft  16  that extends from the handle  14 , a distal end working unit  18  disposed on a distal end of the shaft  16  including a gripper  12 , and a drive unit  22  in which a motor  20  (drive source) is provided for driving the distal end working unit  18 , and which is capable of attachment and detachment to and from the handle  14 . A manipulator main body  11 A is made up from the handle  14 , the shaft  16 , and the distal end working unit  18 . 
         [0036]    In the following description, in relation to the manipulator  10 A and the constituent elements thereof, in the drawings, the X direction indicates a forward and rearward longitudinal direction, the Y direction indicates a left and right lateral direction, and the Z direction indicates an up and down vertical direction. In particular, the X1 direction is a forward direction, and the X2 direction is a rearward direction. 
         [0037]    With the manipulator  10 A according to the present embodiment, the manipulator main body  11 A and the drive unit  22  can be attached and detached to and from each other. In a state in which the drive unit  22  is taken out from the manipulator main body  11 A, the driving force from the motor  20  is not transmitted to the distal end working unit  18 . On the other hand, in a state in which the drive unit  22  is mounted on the handle  14 , when the motor  20  is driven, the driving force of the motor  20  is transmitted to the distal end working unit  18 . 
         [0038]    The manipulator  10 A shown in  FIG. 1  is constituted as a needle driver that is capable of grasping a medical needle (a curved needle or the like) with the gripper  12  disposed on the distal end thereof. The gripper  12  is a portion that carries out a surgical treatment, and in the illustrated example, the gripper  12  includes first and second gripper members  12   a,    12   b , and is configured to carry out opening and closing operations on the basis of a predetermined opening and closing operation axis Og. In the illustrated example, although concerning the gripper  12 , a case has been described in which the first gripper member  12   a  is constituted as a fixed member and the second gripper member  12   b  is constituted as a movable member, both of the gripper members  12   a,    12   b  may be constituted as movable members. 
         [0039]    The posture of the distal end working unit  18  including the gripper  12  can be changed at a plurality of degrees of freedom with respect to the shaft  16 . In the present embodiment, the distal end working unit  18  can carry out a “tilting operation” (swinging operation) in which the distal end working unit  18  is operated to tilt in left and right (transverse or lateral) directions with respect to an axis of the shaft  16  about a tilt axis Oy, and a “rolling operation” in which the distal end working unit  18  is rotated about the axial line (roll axis Or) in the longitudinal direction of the distal end working unit  18 . The tilt axis Oy is not limited to being set in the vertical direction, and the tilt axis Oy may be set in a different direction that intersects the axis of the shaft  16 . 
         [0040]    The shaft  16  is an oblong small diameter tubular member that connects the handle  14  and the distal end working unit  18 . In  FIG. 1 , a portion of the shaft  16  is omitted from illustration, and the shaft is rendered shorter than it actually is. A plurality of members configured to make up a power transmission mechanism are inserted through and arranged in a hollow portion of the shaft  16 . Such a power transmission mechanism transmits, from the handle  14  to the distal end working unit  18 , power that is necessary for carrying out the opening and closing operation of the gripper  12 , and the rolling operation and the tilting operation of the distal end working unit  18 . 
         [0041]    A structure may be provided in which one or a plurality of joints are provided at an intermediate location in the longitudinal direction of the shaft  16  to enable the tilting operation by the joints. Further, a structure may be provided in which the rolling operation is enabled at the proximal end portion of the shaft  16 , or at an intermediate location in the longitudinal direction of the shaft  16 . 
         [0042]    The handle  14  is a portion that is gripped by an operator during use of the manipulator  10 A, and by input operating members (in the present embodiment, a later described tilt wheel  26 , a rolling switch  28 , and a lever  30 ) being touched and operated by a finger, drives the distal end working unit  18  that is connected to the distal end of the shaft  16 . 
         [0043]    The handle  14  comprises a body portion  24  that is connected to a proximal end of the shaft  16 , the tilt wheel  26  constituting a tilt operating unit that is provided on the body portion  24 , the rolling switch  28  (switch operating member) constituting a rolling operating unit that is provided on the body portion  24 , and the lever  30  constituting an opening and closing operating unit that is provided on the body portion  24 . 
         [0044]    The body portion  24  makes up a part that is gripped by a user when the manipulator  10 A is used. In the present embodiment, the body portion  24  is constituted in the form of a stick that extends over a certain length in the axial direction of the shaft  16 . The body portion  24  includes a casing  32  made up from a left cover  32   a  and a right cover  32   b,  with frames, drive components (pulleys, gears, wires, etc.) or the like being arranged in the interior of the casing  32 . For insertion and installation of the drive unit  22  in the interior of the casing  32  from the rear side, a rearwardly open installation hole  33  is formed. 
         [0045]    The tilt wheel  26  for carrying out a tilting operation of the distal end working unit  18  is disposed near the center in the longitudinal direction of the body portion  24 , and is rotatable about the vertically oriented axis of the handle  14 . The tilt wheel  26  is constituted as a manual operating member, such that the tilt wheel  26  partially protrudes from openings  27  provided on left and right sides of the casing  32 . 
         [0046]    When the tilt wheel  26  is operated by being rotated, the operating force applied thereto is transmitted mechanically to the distal end working unit  18  through a tilting operation power transmission system, which is disposed internally in the handle  14  and the shaft  16 , whereupon the distal end working unit  18  is tilted about an axis (tilt axis Oy) in a non-parallel direction with respect to the axis of the shaft  16 . More specifically, when the tilt wheel  26  is rotated clockwise as viewed in plan, the distal end working unit  18  is tilted in a rightward direction about the handle  14 , whereas when the tilt wheel  26  is rotated counterclockwise as viewed in plan, the distal end working unit  18  is tilted in a leftward direction about the handle  14 . 
         [0047]    With the manipulator  10 A of the illustrated example, the rolling switch  28  for carrying out a rolling operation of the distal end working unit  18  is disposed on an upper portion in the vicinity of the distal end of the body portion  24 . In the present embodiment, the rolling switch  28  is constituted as an electrical manipulating portion, which supplies an operating command to the motor  20  through a controller  36 . Because the rolling switch  28  is an electrical switch, the rolling switch  28  is not limited to the location shown in  FIG. 1 , but can be arranged in a different location of the handle  14 . 
         [0048]    In a state in which the drive unit  22  is mounted in the handle  14 , and the power source of the controller  36  is turned on, when the rolling switch  28  is operated and moved, the operating state (position) of the rolling switch  28  is detected by the controller  36 , the motor  20  is driven under the controlling action of the controller  36 , and by the driving force of the motor  20  being transmitted to the distal end working unit  18 , the distal end working unit  18  is rotated about the longitudinal axis (roll axis Or) of the distal end working unit  18 . 
         [0049]    A lever  30  for performing an opening and closing operation of the gripper  12  is disposed on a lower part of the body portion  24 , and is swingably mounted upward and downward about the distal end side thereof which serves as a support point. According to the present embodiment, the lever  30  is constructed as a manual operating member, in which an opening and closing operation of the gripper  12  is carried out by mechanically transmitting to the gripper  12  of the distal end working unit  18  an operating force applied with respect to the lever  30 . More specifically, a structure is provided in which the gripper  12  is opened when the lever  30  is opened, and the gripper  12  is closed when the lever  30  is closed. 
         [0050]    As shown in  FIG. 1 , the drive unit  22  of the manipulator  10 A is used in a condition of being connected to the controller  36  through a cable  42 . The controller  36  controls the supply of power and driving or the like of the motor  20 , and receives electrical power from an external power source. In a state in which the drive unit  22  is mounted on the handle  14 , when the rolling switch  28  is operated, the controller  36  controls driving of the motor  20  in response to operation thereof. The rotation of the motor  20  may be detected, and the motor  20  may be feedback controlled through the controller  36 . 
         [0051]    The form of use can be one in which, concerning the manipulator  10 A that is constructed in the foregoing manner, the manipulator main body  11 A can be discarded after being used a predetermined number of times, whereas the drive unit  22  can be used repeatedly many times by changing the manipulator main body  11 A that is connected to the drive unit  22 . 
         [0052]      FIG. 2  is a perspective view of the drive unit  22 . The drive unit  22  includes a housing  38 , the motor  20  (drive source) disposed inside the housing  38 , and a drive coupling  40  (drive member) that is fixed to an output shaft  21  of the motor  20 . The cable  42  including power lines and signal lines is connected to the proximal end side of the drive unit  22 . 
         [0053]    In a state in which the drive unit  22  is attached to the handle  14  (see  FIG. 1 ), the drive coupling  40 , which is fixed to the output shaft  21  of the motor  20 , is fitted (enmeshed) with a non-illustrated driven coupling (driven member) disposed on the side of the handle  14 . In this state in which the drive coupling  40  and the driven coupling are fitted together, when the motor  20  is rotated, the rotary driving force of the motor  20  is transmitted to the side of the handle  14  through the drive coupling  40  and the driven coupling. 
         [0054]    In the handle  14 , guide rails (not shown) that extend along a longitudinal (forward and rearward) direction of the handle  14 , are provided on both left and right sides on an inside surface of the casing  32 . As shown in  FIG. 2 , groove-shaped guide receiving members  44  that extend in the longitudinal direction of the drive unit  22  are disposed on side surfaces on both left and right sides of the housing  38 . 
         [0055]    When the drive unit  22  is attached with respect to the handle  14 , under a guiding action of the guide rails and the guide receiving members  44 , the drive unit  22  can be moved smoothly relative to the handle  14 . Consequently, the drive unit  22  can be mounted easily and reliably at an accurate positional relationship with respect to the handle  14 . 
         [0056]    As shown in  FIG. 1 , in the drive unit  22 , a lock mechanism  46  is provided that restricts the drive unit  22  so as not to become detached from the handle  14 , in a state in which the drive unit  22  has been attached to the handle  14 . The lock mechanism  46  of the present illustrated example includes an engagement member  48  (see  FIG. 3 ) disposed on the handle  14 , and a lever device  50  disposed on the drive unit  22 . 
         [0057]    As shown in  FIG. 2 , the lever device  50  includes a lever member  52 , an operating tab  54 , and a lever biasing member (not shown). The lever member  52  is swingable with respect to the housing  38 , and is equipped with an engagement pawl  53 . The operating tab  54  is disposed on a proximal end of the lever member  52 . The lever biasing member biases the lever member  52  elastically in a direction in which the engagement pawl  53  projects (a downward direction as shown in the illustrated example). 
         [0058]    When the drive unit  22  is attached to the handle  14 , the engagement pawl  53  disposed on the lever member  52  engages with the engagement member  48  provided inside the handle  14 , whereby the drive unit  22  is prevented from becoming detached and separating away from the handle  14 . On the other hand, by releasing the engagement between the engagement member  48  and the engagement pawl  53  of the lever member  52 , the drive unit  22  is capable of being detached from the handle  14 . 
         [0059]    In the manipulator  10 A, there is further provided an electrical connection mechanism that electrically connects the handle  14  and the drive unit  22  accompanying attachment of the drive unit  22  to the handle  14 . The electrical connection mechanism includes handle-side terminal members  60  (see  FIG. 3 ) disposed on the handle  14 , and unit-side terminal members  62  (see  FIG. 4 ) disposed on the drive unit  22 . 
         [0060]    The handle-side terminal members  60  and the unit-side terminal members  62  are made from a conductive material. The handle-side terminal members  60  and the unit-side terminal members  62  preferably are constituted from a corrosion-resistant material, for example, stainless steel, titanium, a titanium alloy, etc. 
         [0061]    As shown in  FIG. 3 , in the handle  14 , a unit holder  64  is provided that extends in forward and rearward directions of the handle  14 . On an upper surface of a proximal end side of the unit holder  64 , plural handle-side terminal members  60  are provided. In the present illustrated example, five handle-side terminal members  60   a  to  60   e  are arranged at intervals in the widthwise direction (lateral direction: Y direction) of the handle  14 . 
         [0062]    The central handle-side terminal member  60   c  and the two handle-side terminal members  60   a,    60   e  on outermost sides thereof are connected, through respective lead wires  91   a  to  91   c  connected thereto, to a switch mechanism  66  including the rolling switch  28  (see  FIGS. 1 ,  5 , and  6 ). The handle-side terminal members  60   a,    60   c,    60   e  function as switch terminals (operation terminals) for detecting the operating state of the rolling switch  28 . 
         [0063]    The other two handle-side terminal members  60   b,    60   d  are electrically connected via a short-circuiting member  63 . The handle-side terminal members  60   b,    60   d  function as detection terminals for detecting whether or not the drive unit  22  has been attached with respect to the handle  14 . 
         [0064]    In the present illustrated example, among the five handle-side terminal members  60   a  to  60   e,  the switch terminals and the detection terminals are arranged alternately one by one. However, the manner of arrangement thereof is not limited, and the switch terminals and the detection terminals may be arranged in any manner. 
         [0065]      FIG. 4  is a perspective view as seen obliquely from below the drive unit  22 . In the present embodiment, five unit-side terminal members  62   a  to  62   e  are disposed mutually in parallel and with intervals therebetween in the circumferential direction of the motor  20 . The respective unit-side terminal members  62  are shaped in the form of elongate narrow pins, with the longitudinal directions thereof being arranged along the longitudinal direction of the drive unit  22 . The respective unit-side terminal members  62  may be plate-shaped. 
         [0066]    In a state in which the drive unit  22  is mounted on the handle  14 , the central unit-side terminal member  62   c  and the outermost unit-side terminal members  62   a,    62   e  are in contact with the central handle-side terminal member  60   c  and the outermost handle-side terminal members  60   a ,  60   e  (switch terminals) provided on the handle  14 , whereas the remaining two unit-side terminal members  62   b,    62   d  are in contact with the two handle-side terminal members  60   b,    60   d  (detection terminals) provided on the handle  14 . 
         [0067]      FIG. 5  is a perspective view showing a switch mechanism  66  including the rolling switch  28 .  FIG. 6  is an exploded perspective view of the switch mechanism  66 .  FIG. 7  is a transverse cross-sectional view of the switch mechanism  66  taken along line VII-VII of  FIG. 5 . As shown in  FIGS. 5 through 7 , the switch mechanism  66  includes a switch frame  68 , the rolling switch  28  that makes up the switch operating member, a biasing member  70 , a movable-side terminal member  72 , a first fixed-side terminal member  74 , and a second fixed-side terminal member  76 . 
         [0068]    The switch frame  68  is fixed to a non-illustrated frame disposed in the interior of a casing of the handle  14 . The switch frame  68  swingably supports the rolling switch  28 . On the switch frame  68  of the present illustrated example, a switch pedestal  78 , which swingably supports the rolling switch  28 , is formed in an upwardly projecting manner. The switch pedestal  78  includes an arcuate slide surface  78   a.  An insertion hole  80  that penetrates in a vertical direction is disposed in the switch pedestal  78 . 
         [0069]    The rolling switch  28  is a portion that is operated by a finger of the user of the manipulator  10 A. The rolling switch  28  of the present illustrated example includes an operating element  82  that is constituted in an arcuate shape, and a projecting member  84  that projects from a central rear side of the operating element  82 . On an outer peripheral part of the operating element  82 , a plurality (three) of arcuate recesses  82   a  are provided to which the finger can easily be applied. 
         [0070]    A lower surface of the operating element  82  is supported slidably by a slide surface  78   a  of the switch pedestal  78 . Consequently, the rolling switch  28  can be swung in the A direction and the B direction shown in  FIG. 7 . A pivotal center of the rolling switch  28  is coincident with the center of curvature of the arcuately shaped slide surface  78   a.  As shown in  FIG. 9 , in a modification of the rolling switch  28 , the rolling switch  28  may be supported through a rotating shaft  69  on the switch frame  68 , and thereby arranged in a swingable manner. Alternatively, according to another modification of the rolling switch  28 , the rolling switch  28  may be arranged so as to be displaced linearly (e.g., displaceable in the Y direction). 
         [0071]    The projecting member  84  provided on the rolling switch  28  is inserted into the insertion hole  80  provided on the switch pedestal  78 . In this case, the projecting member  84  is capable of being displaced in the A direction and the B direction inside the insertion hole  80 . 
         [0072]    The biasing member  70  elastically biases the rolling switch  28  toward a neutral position (the position shown in  FIG. 7 ) in the movement range of the rolling switch  28  at all times. In a state in which the rolling switch  28  is not pressed in left and right directions, the rolling switch  28  is maintained in the neutral position under an elastic action of the biasing member  70 . 
         [0073]    The biasing member  70  is supported by a supporting projection  86  provided on the switch frame  68 . The biasing member  70  of the present illustrated example is constituted by a torsion spring  70 A. A coil part  88  of the torsion spring  70 A is fixed to the supporting projection  86 . A pair of arm members  90   a,    90   b  of the torsion spring  70 A extend from the coil part  88  to the operating element  82 . A latching projection  87  disposed on the switch frame  68  is sandwiched between the pair of arm members  90   a,    90   b  of the torsion spring  70 A. In a state in which the rolling switch  28  is in the neutral position, a small gap (amount of play) exists between the rolling switch  28  and the pair of arm members  90   a,    90   b.    
         [0074]    The movable-side terminal member  72  is fixed to the projecting member  84 . The movable-side terminal member  72  of the present illustrated embodiment includes a base portion  93  fixed to the projecting member  84  by a fixing part  92  (a screw in the illustrated example), and a first contact portion  94  (movable-side contact portion) and a second contact portion  96  (movable-side contact portion), which are bent at substantially right angles at both ends of the base portion  93 , and which extend toward the operating element  82  along the projecting member  84 . As shown in  FIG. 6 , one end of the lead wire  91   a  is connected to a connection terminal  97  that extends out from the base portion  93 . The other end of the lead wire  91  a is connected to the handle-side terminal member  60   c  (see  FIG. 3 ). 
         [0075]    Between the projecting member  84  and the movable-side terminal member  72 , a holder  98  is arranged for preventing the rolling switch  28  from being pulled out from the switch pedestal  78 . By insertion of a positioning projection  85  disposed on the projecting member  84  into a positioning hole  99  provided on the holder  98 , the holder  98  is positioned with respect to the projecting member  84 . A portion of the holder  98  engages slidably in the A direction and the B direction on an arcuate lower surface  78   d  (see  FIG. 7 ) disposed on a lower part of the switch pedestal  78 . 
         [0076]    The first fixed-side terminal member  74  and the second fixed-side terminal member  76  are fixed to the switch frame  68 . The first fixed-side terminal member  74  of the present illustrated example includes a first fixed base portion  100 , which is fixed to the switch frame  68  on one side relative to the projecting member  84 , and a first contact plate  102  (first fixed-side contact portion), which is bent and extends out from the first fixed base portion  100  toward the rolling switch  28 . The second fixed-side terminal member  76  of the present illustrated example includes a second fixed base portion  104 , which is fixed to the switch frame  68  on another side relative to the projecting member  84 , and a second contact plate  106  (second fixed-side contact portion), which is bent and extends out from the second fixed base portion  104  toward the rolling switch  28 . 
         [0077]    The respective fixed base portions  100 ,  104  are fixed to the switch frame  68  by fixing parts  108 ,  109  (screws in the illustrated example). The lead wire  91   b  is connected to a connection terminal  101  that extends out from the first fixed base portion  100  of the first fixed-side terminal member  74 . The other end of the lead wire  91   b  is connected to the handle-side terminal member  60   a.  The lead wire  91   c  is connected to a connection terminal  105  (see  FIG. 6 ) that extends out from the second fixed base portion  104  of the second fixed-side terminal member  76 . The other end of the lead wire  91   c  is connected to the handle-side terminal member  60   e.    
         [0078]    As shown in  FIG. 7 , in the interior of the insertion hole  80 , the first contact plate  102  faces the first contact portion  94  of the movable-side terminal member  72 , and further is arranged so as to face an inner wall surface of a left side wall portion  78   b  on the switch pedestal  78  with a slight gap therebetween. Further, in the interior of the insertion hole  80 , the second contact plate  106  faces the second contact portion  96  of the movable-side terminal member  72 , and further is arranged so as to face an inner wall surface of a right side wall portion  78   c  on the switch pedestal  78  with a slight gap therebetween. Therefore, when pressed by the movable-side terminal member  72 , the respective contact plates  102 ,  106  are elastically deformable over the gaps. Contact projections  103 ,  107 , which project out on sides of the movable-side terminal member  72 , are provided on the respective contact plates  102 ,  106 . 
         [0079]    The movable-side terminal member  72 , the first fixed-side terminal member  74 , and the second fixed-side terminal member  76  are constituted from a corrosion-resistant material, for example, stainless steel, titanium, a titanium alloy, etc. Alternatively, the movable-side terminal member  72 , the first fixed-side terminal member  74 , and the second fixed-side terminal member  76  may be constituted from conductive materials, and a conductive coating that exhibits corrosion resistance may be applied to at least the electrical contact portions (the first contact portion  94 , the second contact portion  96 , the first contact plate  102 , the second contact plate  106 ) thereof. Examples of constituent materials for such a conductive coating include nickel, gold, silver, rhodium, chromium, and the like. 
         [0080]    The manipulator  10 A according to the present embodiment is constructed basically as described above. Next operations and advantages of the manipulator  10 A will be described. 
         [0081]    In the switch mechanism  66 , which is constructed as described above, when the rolling switch  28  is positioned in the neutral position as shown in  FIG. 7 , the movable-side terminal member  72  is kept out of contact with either one of the first fixed-side terminal member  74  and the second fixed-side terminal member  76 . Therefore, electricity is not conducted between the central handle-side terminal member  60   c  and the handle-side terminal member  60   a  on the left-hand side (see  FIG. 3 ). Further, electricity is not conducted between the central handle-side terminal member  60   c  and the handle-side terminal member  60   e  on the right-hand side (see  FIG. 3 ). Consequently, a rolling operation of the distal end working unit  18  is not carried out. 
         [0082]    As shown in  FIG. 8 , when the rolling switch  28  is operated and moved to the left (A direction) on the switch pedestal  78 , the first contact portion  94  of the movable-side terminal member  72  and the first contact plate  102  of the first fixed-side terminal member  74  are placed in contact. Consequently, electricity is conducted between the central handle-side terminal member  60   c  and the handle-side terminal member  60   a  on the left-hand side (see  FIG. 3 ), and conduction of electricity therebetween is detected by the controller  36  (see  FIG. 1 ). As a result, the controller  36  controls driving of the motor  20 , and in the distal end working unit  18 , a left-handed rolling operation is carried out. 
         [0083]    When the rolling switch  28  is operated and moved to the right (B direction) on the switch pedestal  78 , the second contact portion  96  of the movable-side terminal member  72  and the second contact plate  106  of the second fixed-side terminal member  76  are placed in contact. Consequently, electricity is conducted between the central handle-side terminal member  60   c  and the handle-side terminal member  60   e  on the right-hand side (see  FIG. 3 ), and conduction of electricity therebetween is detected by the controller  36 . As a result, the controller  36  controls driving of the motor  20 , and in the distal end working unit  18 , a right-handed rolling operation is carried out. 
         [0084]    In this case, according to the present embodiment, in the switch mechanism  66 , the movable-side terminal member  72 , the first fixed-side terminal member  74 , and the second fixed-side terminal member  76  are constituted from a corrosion-resistant material. For this reason, even if the manipulator main body  11 A is subjected to a sterilization treatment (autoclave sterilization, etc.) in which steam is used, it is unlikely for an oxide layer to be formed on the movable-side terminal member  72 , the first fixed-side terminal member  74 , and the second fixed-side terminal member  76 , and conductivity therebetween can be maintained. 
         [0085]    Further, when the first contact portion  94  of the movable-side terminal member  72  and the first contact plate  102  of the first fixed-side terminal member  74  come into contact, the first contact plate  102 , as a result of being pressed by the first contact portion  94 , is displaced slightly accompanying elastic deformation thereof. Along therewith, the first contact portion  94  and the first contact plate  102  are displaced relative to each other slightly in the surface direction of the first contact plate  102 . Consequently, the first contact portion  94  and the first contact plate  102  slide while abutting against each other. More specifically, the first contact portion  94  and the first contact plate  102  rub against each other at the location of contact therebetween. 
         [0086]    Further, similarly, when the second contact portion  96  of the movable-side terminal member  72  and the second contact plate  106  of the second fixed-side terminal member  76  come into contact, the second contact plate  106 , as a result of being pressed by the second contact portion  96 , is displaced slightly accompanying elastic deformation thereof. Along therewith, the second contact portion  96  and the second contact plate  106  are displaced relative to each other slightly in the surface direction of the second contact plate  106 . Consequently, the second contact portion  96  and the second contact plate  106  slide while abutting against each other. More specifically, the second contact portion  96  and the second contact plate  106  rub against each other at the location of contact therebetween. 
         [0087]    In this manner, accompanying operation of the rolling switch  28  that constitutes the switch operating member, at a time of contact between the movable-side terminal member  72 , and the first fixed-side terminal member  74  or the second fixed-side terminal member  76 , the first contact portion  94  and the first contact plate  102 , or the second contact portion  96  and the second contact plate  106  rub against each other. In addition, at the portions subjected to such mutual rubbing, an effect (refreshing effect) by which the electrical contact is activated can be obtained. 
         [0088]    Consequently, for example, as a result of performing a sterilization treatment (autoclave sterilization, etc.) using steam with respect to the manipulator main body  11 A, even if corrosion (an oxide layer) occurs in any one of the first contact portion  94 , the second contact portion  96 , the first contact plate  102 , and the second contact plate  106  or even if foreign matter is deposited or adhered thereon, the electrical connection can suitably be assured due to the refreshing effect. 
         [0089]    In the case of the present embodiment, when the first fixed-side terminal member  74  and the second fixed-side terminal member  76  come into contact respectively with the movable-side terminal member  72 , contact regions thereof (the first contact plate  102 , the second contact plate  106 ) with the movable-side terminal member  72  are displaced elastically. According to such a structure, when the first contact plate  102  or the second contact plate  106  is pressed by the movable-side terminal member  72  and then displaced elastically, mutual rubbing takes place at the contact regions. Thus, with a simple structure, the aforementioned refreshing effect can be obtained. 
         [0090]    In the present embodiment, the first contact plate  102  and the second contact plate  106  are constituted as elastically deformable plate-shaped bodies. In this manner, in the first contact plate  102  and the second contact plate  106 , since a spring element and an electrically conductive element are integrated into a single member, compared to such a spring element and such an electrically conductive element being constructed separately, the structure is simplified. Incidentally, in a modification of the first fixed-side terminal member  74  and the second fixed-side terminal member  76 , the spring element and the electrically conductive element may be constituted separately. In this case, a structure is adopted in which the electrically conductive terminal part is supported elastically by an elastic member. 
         [0091]    In this manner, with the switch mechanism  66 , when the movable-side terminal member  72  and the first fixed-side terminal member  74  come into contact, the contact location (first contact plate  102 ) of the first fixed-side terminal member  74  with the movable-side terminal member  72  is constituted to be elastically displaceable. Further, when the movable-side terminal member  72  and the second fixed-side terminal member  76  come into contact, the contact location (second contact plate  106 ) of the second fixed-side terminal member  76  with the movable-side terminal member  72  is constituted to be elastically displaceable. 
         [0092]    In contrast thereto, in a modification of the switch mechanism  66 , when the movable-side terminal member  72  and the first fixed-side terminal member  74  come into contact, the contact location (first contact portion  94 ) of the movable-side terminal member  72  with the first fixed-side terminal member  74  may be constituted to be elastically displaceable. Further, when the movable-side terminal member  72  and the second fixed-side terminal member  76  come into contact, the contact location (second contact portion  96 ) of the movable-side terminal member  72  with the second fixed-side terminal member  76  may be constituted to be elastically displaceable. Configurations of this type can be realized by providing gaps between the first contact portion  94  and the projecting member  84 , and between the second contact portion  96  and the projecting member  84 . In accordance with such a configuration, when the movable-side terminal member  72  and the first fixed-side terminal member  74  come into contact, and when the movable-side terminal member  72  and the second fixed-side terminal member  76  come into contact, the respective contact locations thereof rub against each other, and the refreshing effect for electrical contact points is obtained. 
         [0093]    In the case of the present embodiment, since the motor  20  (see  FIG. 1 ), which serves as the drive source, is provided on the side of the drive unit  22 , there is no need to provide electronic devices, which are susceptible to moisture, in the manipulator main body  11 A. Accordingly, a sterilization treatment in which steam is used can suitably be performed on the manipulator main body  11 A. 
         [0094]    The drive unit  22 , which is constructed as described above, can be mounted and used not only with the manipulator main body  11 A, which is constituted as a needle driver, but also with a manipulator main body  11 B, which is constituted as an electrosurgical scalpel, as shown in  FIG. 10 . In this case, by combining together the manipulator main body  11 B and the drive unit  22 , an electrosurgical scalpel type medical manipulator  10 B (hereinafter referred to in an abbreviated form as a “manipulator  10 B”), which is driven by the motor  20 , is constructed. 
         [0095]    The manipulator main body  11 B comprises a handle  110  on which a plurality of input operating members are provided, a shaft  112  that extends from the handle  110 , and a distal end working unit  116  disposed on a distal end of the shaft  112  and including a gripper  114  (end effector). 
         [0096]    The manipulator main body  11 A shown in  FIG. 1  is of an overall stick-like (rod-like) shape suitable for use as a needle driver. In contrast thereto, with the manipulator main body  11 B shown in  FIG. 10 , a grip  117  that projects downwardly on a lower part of the handle  110  is provided, and the handle  110  is in the shape of a pistol as a whole, having a shape that is suitable for use as an electrosurgical scalpel. Further, such a pistol type handle shape also is suitable for use with scissors, a grasping implement, and a peeling implement, etc. 
         [0097]    The gripper  114  is capable of making opening and closing movements, and serves as a portion for gripping biological tissue, and cauterizing the biological tissue by conduction of current through the tissue. The gripper  114  of the present illustrated example includes a first gripper member  114   a  and a second gripper member  114   b,  which are capable of swinging or pivoting in mutually opposite directions about an opening and closing operation axis Og. 
         [0098]    The manipulator main body  11 B may be constructed as a bipolar type of electrical scalpel in which the first gripper member  114   a  and the second gripper member  114   b  are electrically energized at different polarities, or a monopolar type of electrical scalpel in which either one of or both of the first gripper member  114   a  and the second gripper member  114   b  is electrically energized. 
         [0099]    The opening and closing operation of the gripper  114  is carried out by mechanically transmitting the operation of a lever  118 , which is provided on the handle  110 , to the distal end working unit  116  through a non-illustrated opening/closing drive transmission system. More specifically, in the present illustrated example, the lever  118  is constructed as a manual operating member, and opening and closing operations of the gripper  114  are performed not by a motor drive, but by a manual drive on the basis of an operating force from the operator. 
         [0100]    The lever  118  is disposed for displacement in forward and rearward directions with respect to the grip  117 , such that when the lever  118  is pressed out forwardly relative to the grip  117 , the gripper  114  opens, and when the lever  118  is drawn in rearwardly relative to the grip  117 , the gripper  114  is closed. A structure may also be adopted in which the opening/closing operation of the gripper  114  is performed by a motor drive. 
         [0101]    In the manipulator  10 B in accordance with the combination of the manipulator main body  11 B and the drive unit  22 , a power supplying connector  120  is connected to the handle  110 , whereby the manipulator  10 B can be used as an electrosurgical scalpel. The power supplying connector  120  is connected to a non-illustrated high frequency power supply device through an energizing cable  122 , and by the high frequency power supply device, a high frequency voltage is applied in order to electrically energize the gripper  114 . 
         [0102]    The distal end working unit  116  is capable of being tilted laterally (yaw operation) by a bending portion  124  disposed on a distal end of the shaft  112 . The bending portion  124  has a plurality of joint members  126 , which are coupled rotatably within a predetermined angular range to one another. Although in a state in which the joint members  126  are aligned coaxially, the bending portion  124  exhibits a linear shape, when the adjacent joint members  126  themselves are mutually tilted, the bending portion  124  exhibits a curved shape as a whole. 
         [0103]    The tilting operation of the distal end working unit  116  is carried out by the controller  36  controlling driving of the motor  20  based on an operation made with respect to a tilting switch  128  (switch operating member) provided on the handle  110 , and by mechanically transmitting the driving force of the motor  20  to the distal end working unit  116  through the handle  110  and the shaft  112 . More specifically, in the present illustrated example, the tilting switch  128  is constructed as an electrical operating member, and the tilting operation of the distal end working unit  116  is performed by a motor drive. 
         [0104]    The distal end working unit  116 , at a portion thereof located more toward the distal end side than the bending portion  124 , is capable of executing a rolling operation about the roll axis Or. The rolling operation is carried out by mechanically transmitting a rotating operation made with respect to a rotating knob  130  (input operating member), which is provided on the handle  110 , to the distal end working unit  116  through a non-illustrated rolling drive transmission system. More specifically, in the present illustrated example, the rotating knob  130  is constructed as a manual operating member, and the rolling operation of the distal end working unit  116  is performed not by a motor drive, but by a manual drive on the basis of an operating force from the operator. A structure may also be adopted in which the rolling operation of the distal end working unit  116  is performed by a motor drive. 
         [0105]    On an upper end side of the handle  110 , a mounting hole  111  is provided, which opens rearwardly. The drive unit  22  is inserted into the mounting hole  111 , and thus can be mounted with respect to the handle  110 . More specifically, the drive unit  22  is capable of being attached to and detached from the proximal end side of the handle  110 . In a state in which the drive unit  22  is mounted in the handle  110 , so that operating tabs  54 , which are disposed on the drive unit  22 , can be touched and operated by the user, the operating tabs  54  protrude through openings  110   a  provided on side surfaces on left and right sides of the handle  110 . 
         [0106]    Similar to the handle  14  in the manipulator main body  11 A, guide rails (not shown) are provided in the handle  110 . Consequently, under a guiding action of the guide rails and the guide receiving members  44 , the drive unit  22  can move smoothly relative to the handle  110 , and the drive unit  22  can be mounted easily and reliably at an accurate positional relationship with respect to the handle  110 . 
         [0107]    Although omitted from illustration in  FIG. 10 , a driven coupling, which is capable of engaging with the drive coupling  40 , is provided in the handle  110 , as with the handle  14  in the manipulator main body  11 A shown in  FIG. 1 . Consequently, in a state in which the drive unit  22  is mounted with respect to the handle  110 , by engagement of the drive coupling  40  and the driven coupling, a driving force of the motor  20  can be transmitted reliably to the handle  110 . 
         [0108]    Although omitted from illustration in  FIG. 10 , handle-side terminal members  60  (see  FIG. 3 ) are provided in the handle  110 , which are similar to those of the handle  14  in the manipulator main body  11 A shown in  FIG. 1 . In a state in which the drive unit  22  is attached to the handle  110 , the handle-side terminal members  60  and the unit-side terminal members  62  (see  FIG. 4 ) provided on the drive unit  22  are placed in contact. According to this structure, the operating state of the tilting switch  128  can be detected by the controller  36 , and the controller  36  can appropriately control driving of the motor  20 . 
         [0109]    On the handle  110 , similar to the handle  14  of the manipulator main body  11 A shown in  FIG. 1 , an engagement member  48  is provided that is capable of engaging with the lever member  52  disposed on the drive unit  22 . Accordingly, together with attachment of the drive unit  22  with respect to the handle  110 , a condition (locked state) is brought about in which movement of the drive unit  22  in the proximal end direction relative to the handle  110  is prevented. 
         [0110]    In the foregoing manner, with the manipulators  10 A,  10 B, the drive unit  22  can easily and reliably be attached with respect to the handles  14 ,  110  having different functions and shapes. Further, based on an operation of an input operating member (rolling switch  28 , tilting switch  128 ) disposed on the handles  14 ,  110 , the motor  20  can be driven, and the distal end working unit  116  can be operated by the driving force thereof. 
         [0111]    The form of the manipulator main bodies  11 A,  11 B, which enable attachment and detachment of the drive unit  22 , is not limited to the two forms (needle driver, electrosurgical scalpel) described above, and forms having other different functions and shapes, for example, scissors, a grasping forceps, or the like, may be provided. In addition, a suction device, a cleaning device, an energy device, etc., may be provided. 
         [0112]      FIG. 11  is a perspective view showing a switch mechanism  132  including a tilting switch  128 .  FIG. 12  is an exploded perspective view of the switch mechanism  132 .  FIG. 13  is a cross-sectional view of the switch mechanism  132  taken along line XIII-XIII of  FIG. 11 . As shown in  FIGS. 11 through 13 , the switch mechanism  132  includes a switch frame  134 , the tilting switch  128  that makes up the switch operating member, a biasing member  136 , a movable-side terminal member  138 , a first fixed-side terminal member  140 , and a second fixed-side terminal member  142 . 
         [0113]    The switch frame  134  is fixed to a non-illustrated frame disposed in the interior of a casing of the handle  110 . A support hole  135  is formed to penetrate in the thickness direction of the switch frame  134 . 
         [0114]    The tilting switch  128  is a portion that is operated by a finger of the user of the manipulator  10 B. The tilting switch  128  of the present illustrated example includes an operating element  144  that is constituted in a substantially circular shape, and a projecting member  146  that projects from the operating element  144 . Further, a circumferential side wall portion  148  that extends in a circumferential direction is disposed on the operating element  144 . On an outer circumferential part of the circumferential side wall portion  148 , a plurality of arcuate recesses  148   a  are provided to which the finger can easily be applied. Inwardly projecting engagement projections  150   a,    150   b  are disposed on an inner circumferential part of the circumferential side wall portion  148 . 
         [0115]    A distal end side portion of the projecting member  146  is constituted as a cylindrically shaped switch shaft  152 . The switch shaft  152  is inserted into the support hole  135 . By this feature, the tilting switch  128  is supported pivotally about the center of the switch shaft  152  with respect to the switch frame  134 . Further, in a modification of the tilting switch  128 , the tilting switch  128  may be disposed swingably by an arcuately shaped slide surface. Alternatively, according to another modification of the tilting switch  128 , the tilting switch  128  may be arranged so as to be displaced linearly (e.g., displaceable in the Y direction). 
         [0116]    A fixing part  153  (a screw in the illustrated example) is fixed to the switch shaft  152  through a washer  151 , and thereby, the tilting switch  128  is prevented from being pulled off from the switch frame  134 . 
         [0117]    A biasing member  136  elastically biases the tilting switch  128  toward a neutral position (the position shown in  FIG. 13 ) in the movement range of the tilting switch  128  at all times. In a state in which the tilting switch  128  is not pressed in left and right directions, the tilting switch  128  is maintained in the neutral position under an elastic action of the biasing member  136 . 
         [0118]    The biasing member  136  is supported by a projecting member  146  provided on the tilting switch  128 . The biasing member  136  of the present illustrated example is constituted by a torsion spring  136 A. A root portion  154  of the projecting member  146  is inserted into a coil part  156  of the torsion spring  136 A. A pair of arm members  158   a,    158   b  of the torsion spring  136 A extend from the coil part  156  to a circumferential side wall portion  148  of the tilting switch  128 , and intersect each other as viewed in plan. 
         [0119]    In a state in which the tilting switch  128  is in the neutral position, the pair of arm members  158   a,    158   b  of the torsion spring  136 A are caught on latching projections  160   a,    160   b,  which are provided on the switch frame  134 . As shown in  FIG. 13 , in a state in which the tilting switch  128  is in the neutral position, a small gap (amount of play) exists between the engagement projections  150   a,    150   b  and the pair of arm members  158   a ,  158   b.    
         [0120]    The movable-side terminal member  138  is fixed to the tilting switch  128 . As shown in  FIG. 12 , the movable-side terminal member  138  of the present illustrated embodiment includes an arcuate base portion  164  fixed to the tilting switch  128  by a fixing part  162  (a screw in the illustrated example), and a first contact portion  166   a  (movable-side contact portion) and a second contact portion  166   b  (movable-side contact portion), which are bent at substantially right angles at both ends of the base portion  164 , and which extend toward the switch frame  134 . 
         [0121]    In the first contact portion  166   a,  an opposite side thereof from a side in contact with the first fixed-side terminal member  140  is supported by a contact support member  168  provided on the switch frame  134 . In the second contact portion  166   b,  an opposite side thereof from a side in contact with the second fixed-side terminal member  142  is supported by a contact support member  170  provided on the switch frame  134 . 
         [0122]    As shown in  FIG. 12 , a connection terminal  165  projects out from the base portion  164 . Similar to the handle  14  in the manipulator main body  11 A, lead wires  91   a  to  91   c  (see  FIG. 3 ) are provided in the handle  110 . The connection terminal  165  is connected through the lead wire  91   a  (see  FIG. 3 ) to the handle-side terminal member  60   c  (see  FIG. 3 ). 
         [0123]    The first fixed-side terminal member  140  and the second fixed-side terminal member  142  are fixed to the switch frame  134 . The first fixed-side terminal member  140  of the present illustrated example includes a first fixed base portion  172 , which is fixed to the switch frame  134  on one side in the lateral direction (Y direction), and a first contact plate  174  (first fixed-side contact portion), which is bent and extends out from the first fixed base portion  172  toward the tilting switch  128 . The second fixed-side terminal member  142  of the present illustrated example includes a second fixed base portion  176 , which is fixed to the switch frame  134  on another side in the lateral direction (Y direction), and a second contact plate  178  (second fixed-side contact portion), which is bent and extends out from the second fixed base portion  176  toward the tilting switch  128 . 
         [0124]    The respective fixed base portions  172 ,  176  are fixed to the switch frame  134  by fixing parts  180 ,  182  (screws in the illustrated example). A connection terminal  173  that extends out from the first fixed base portion  172  of the first fixed-side terminal member  140  is connected through the lead wire  91   b  to the handle-side terminal member  60   a  (see  FIG. 3 ). A connection terminal  177  that extends out from the second fixed base portion  176  of the second fixed-side terminal member  142  is connected through the lead wire  91   c  to the handle-side terminal member  60   e  (see  FIG. 3 ). 
         [0125]    As shown in  FIG. 12 , the first contact plate  174  faces the first contact portion  166   a  of the movable-side terminal member  138 , and further is arranged so as to face a wall portion  160  provided on the switch frame  134  with a slight gap therebetween. The second contact plate  178  faces the second contact portion  166   b  of the movable-side terminal member  138 , and further is arranged so as to face the wall portion  160  with a slight gap therebetween. Therefore, when pressed by the movable-side terminal member  138 , the respective contact plates  174 ,  178  are elastically deformable over the gaps. Contact projections  175 ,  179 , which project out toward the movable-side terminal member  138 , are provided on the respective contact plates  174 ,  178 . 
         [0126]    The movable-side terminal member  138 , the first fixed-side terminal member  140 , and the second fixed-side terminal member  142  are constituted from a corrosion-resistant material, for example, stainless steel, titanium, a titanium alloy, etc. Alternatively, the movable-side terminal member  138 , the first fixed-side terminal member  140 , and the second fixed-side terminal member  142  may be constituted by conductive materials, and a conductive coating that exhibits corrosion resistance may be applied to at least the electrical contact portions (the first contact portion  166   a,  the second contact portion  166   b,  the first contact plate  174 , the second contact plate  178 ) thereof. Examples of constituent materials for such a conductive coating include nickel, gold, silver, rhodium, chromium, and the like. 
         [0127]    As shown in  FIG. 13 , when the tilting switch  128  is positioned in the neutral position, the movable-side terminal member  138  is kept out of contact with either one of the first fixed-side terminal member  140  and the second fixed-side terminal member  142 . Therefore, electricity is not conducted between the central handle-side terminal member  60   c  and the handle-side terminal member  60   a  on the left-hand side (see  FIG. 3 ). Further, electricity is not conducted between the central handle-side terminal member  60   c  and the handle-side terminal member  60   e  on the right-hand side (see  FIG. 3 ). Consequently, a tilting operation (yaw operation) of the distal end working unit  116  is not carried out. 
         [0128]    In the switch mechanism  132 , which is constructed as described above, as shown in  FIG. 14 , when the tilting switch  128  is operated and moved in the C direction, the first contact portion  166   a  of the movable-side terminal member  138  and the first contact plate  174  of the first fixed-side terminal member  140  are placed in contact. Consequently, electricity is conducted between the central handle-side terminal member  60   c  and the handle-side terminal member  60   a  on the left-hand side (see  FIG. 3 ), and conduction of electricity therebetween is detected by the controller  36  (see  FIG. 10 ). As a result, the controller  36  controls driving of the motor  20 , and in the distal end working unit  116 , a left-handed tilting operation (yaw operation) is carried out. 
         [0129]    Conversely to  FIG. 14 , when the tilting switch  128  is operated and moved in the D direction, the second contact portion  166   b  of the movable-side terminal member  138  and the second contact plate  178  of the second fixed-side terminal member  142  are placed in contact. Consequently, electricity is conducted between the central handle-side terminal member  60   c  and the handle-side terminal member  60   e  on the right-hand side (see  FIG. 3 ), and conduction of electricity therebetween is detected by the controller  36 . As a result, the controller  36  controls driving of the motor  20 , and in the distal end working unit  116 , a right-handed tilting operation (yaw operation) is carried out. 
         [0130]    In this case, in the switch mechanism  132 , the movable-side terminal member  138 , the first fixed-side terminal member  140 , and the second fixed-side terminal member  142  are constituted from a corrosion-resistant material. For this reason, even if the manipulator main body  11 B is subjected to a sterilization treatment (autoclave sterilization, etc.) in which steam is used, it is unlikely for an oxide layer to be formed on the movable-side terminal member  138 , the first fixed-side terminal member  140 , and the second fixed-side terminal member  142 , and conductivity therebetween can be maintained. 
         [0131]    Further, when the first contact portion  166   a  of the movable-side terminal member  138  and the first contact plate  174  of the first fixed-side terminal member  140  come into contact, the first contact plate  174 , as a result of being pressed by the first contact portion  166   a,  is displaced slightly accompanying elastic deformation thereof. Along therewith, the first contact portion  166   a  and the first contact plate  174  are displaced relative to each other slightly in the surface direction of the first contact plate  174 . Consequently, the first contact portion  166   a  and the first contact plate  174  slide while abutting against each other. More specifically, the first contact portion  166   a  and the first contact plate  174  rub against each other at the location of contact therebetween. 
         [0132]    Further, similarly, when the second contact portion  166   b  of the movable-side terminal member  138  and the second contact plate  178  of the second fixed-side terminal member  142  come into contact, the second contact plate  178 , as a result of being pressed by the second contact portion  166   b,  is displaced slightly accompanying elastic deformation thereof. Along therewith, the second contact portion  166   b  and the second contact plate  178  are displaced relative to each other slightly in the surface direction of the second contact plate  178 . Consequently, the second contact portion  166   b  and the second contact plate  178  slide while abutting against each other. More specifically, the second contact portion  166   b  and the second contact plate  178  rub against each other at the location of contact therebetween. 
         [0133]    In this manner, when the tilting switch  128  is operated to thereby bring the movable-side terminal member  138  into contact with the first fixed-side terminal member  140  or the second fixed-side terminal member  142 , the first contact portion  166   a  and the first contact plate  174 , or the second contact portion  166   b  and the second contact plate  178  rub against each other. In addition, at the portions subjected to such mutual rubbing, an effect (refreshing effect) by which the electrical contact is activated can be obtained. 
         [0134]    Consequently, for example, even if the manipulator main body  11 B is subjected to a sterilization treatment (autoclave sterilization, etc.) using steam, whereby corrosion (an oxide layer) in any one of the first contact portion  166   a,  the second contact portion  166   b,  the first contact plate  174 , and the second contact plate  178  occurs or whereby foreign matter is deposited or adhered thereon, the electrical connection can suitably be assured as a result of the refreshing effect. 
         [0135]    With the switch mechanism  132 , when the first fixed-side terminal member  140  and the second fixed-side terminal member  142  come into contact respectively with the movable-side terminal member  138 , contact regions thereof (the first contact plate  174 , the second contact plate  178 ) with the movable-side terminal member  138  are displaced elastically. According to such a structure, when the first fixed-side terminal member  140  or the second fixed-side terminal member  142  is displaced elastically as a result of being pressed by the movable-side contact portions, mutual rubbing takes place at the contact regions. Thus, with a simple structure, the aforementioned refreshing effect can be obtained. 
         [0136]    In the switch mechanism  132 , the first contact plate  174  and the second contact plate  178  are constituted as elastically deformable plate-shaped bodies. In this manner, in the first contact plate  174  and the second contact plate  178 , since the spring element and the electrically conductive element thereof are integrated as a single member, compared to the spring element and the electrically conductive element being constructed separately, the structure is simplified. 
         [0137]    In this manner, with the switch mechanism  132 , when the movable-side terminal member  138  and the first fixed-side terminal member  140  come into contact, the contact location (first contact plate  174 ) of the first fixed-side terminal member  140  with the movable-side terminal member  138  is constituted to be elastically displaceable. Further, when the movable-side terminal member  138  and the second fixed-side terminal member  142  come into contact, the contact location (second contact plate  178 ) of the second fixed-side terminal member  142  with the movable-side terminal member  138  is constituted to be elastically displaceable. 
         [0138]    In contrast thereto, in a modification of the switch mechanism  132 , when the movable-side terminal member  138  and the first fixed-side terminal member  140  come into contact, the contact location (first contact portion  166   a ) of the movable-side terminal member  138  with the first fixed-side terminal member  140  may be constituted to be elastically displaceable. Further, when the movable-side terminal member  138  and the second fixed-side terminal member  142  come into contact, the contact location (second contact portion  166   b ) of the movable-side terminal member  138  with the second fixed-side terminal member  142  may be constituted to be elastically displaceable. Configurations of this type can be realized by providing gaps respectively between the first contact portion  166   a  and the contact support member  168 , and between the second contact portion  166   b  and the contact support member  170 . In accordance with such a configuration, when the movable-side terminal member  138  and the first fixed-side terminal member  140  come into contact, and when the movable-side terminal member  138  and the second fixed-side terminal member  142  come into contact, the respective contact locations thereof rub against each other, and the refreshing effect is obtained. 
         [0139]      FIGS. 15A and 15B  are views showing another structural example for returning the tilting switch  128  to the neutral position. In  FIGS. 15A and 15B , the movable-side terminal member  138 , the first fixed-side terminal member  140 , and the second fixed-side terminal member  142  are omitted from illustration. 
         [0140]    In  FIG. 15A , the coil part  156  of the torsion spring  136 B is supported by the projecting member  146  of the tilting switch  128 . A pair of engagement projections  188   a,    188   b  are disposed on the tilting switch  128 . Without intersecting each other as viewed in plan, a pair of arms  187   a,    187   b  of the torsion spring  136 B are caught respectively on the engagement projections  188   a,    188   b,  from outer sides of the pair of engagement projections  188   a,    18   b.    
         [0141]    Distal end sides of the pair of arms  187   a,    187   b  are capable of engaging with latching projections  190   a,    190   b  provided on the side of the switch frame  134 . By the pair of arms  187   a,    187   b  being engaged with the latching projections  190   a,    190   b,  the biasing member  136  elastically biases the tilting switch  128  toward a neutral position in the movement range of the tilting switch  128  at all times. Accordingly, as shown in  FIG. 15A , in a state in which the tilting switch  128  is not rotationally operated, the tilting switch  128  is maintained in the neutral position under an elastic action of the biasing member  136 . 
         [0142]    When the tilting switch  128  is rotationally operated in one direction from the neutral position, as shown in  FIG. 15B , although one of the arms  187   a  is latched by the latching projection  190   a  and thus is not displaced, the other arm  187   b  is pressed by the other engagement projection  188   b,  and is displaced in the same direction as the direction of rotation of the tilting switch  128 . In the state shown in  FIG. 15B , upon separating the finger of the operator away from the tilting switch  128 , based on an elastic restorative force of the torsion spring  136 B, the arm  187   b  presses the other engagement projection  188   b,  whereupon the tilting switch  128  is rotated. As a result, the tilting switch  128  is restored to the neutral position shown in  FIG. 15A . Also if the tilting switch  128  is rotationally operated in a direction opposite to that shown in  FIG. 15B , in a similar manner, upon separating the finger away from the tilting switch  128 , by the elastic restorative force of the biasing member  136 , the tilting switch  128  is restored to the neutral position. 
         [0143]    Although certain preferred embodiments of the present invention have been shown and described in detail above, it should be understood that various changes and modifications may be made to the embodiments without departing from the scope of the invention as set forth in the appended claims.