Abstract:
A method of performing a surgical procedure on an affected region in a body cavity includes steps of introducing the distal end, and first and second bendable joints, of a rod-shaped member into the body cavity having the affected region, engaging a body portion in the body cavity, other than the affected region, with the manipulating element, manipulating the body portion other than the affected region using the manipulating element, so as to increase a spacing around the affected region in the body cavity, and bending at least one of said first and second joints so as to increase a spacing between the rod-shaped member and the affected region in the body cavity.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a divisional of and claims the benefit of priority from U.S. application Ser. No. 12/821,716 filed on Jun. 23, 2010, which is a continuation-in-part of and claims the benefit of priority from U.S. Application Ser. No. 12/327,189 filed Dec. 3, 2008, the entire contents of each of both of which are hereby incorporated by reference. U.S. application Ser. No. 12/327,189, claims the benefit of Japanese Patent Application No. 2007-339211, filed on Dec. 28, 2007. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a surgical procedure using a medical manipulator having a distal-end joint operable by flexible members that are actuated by actuators. 
         [0004]    2. Description of the Related Art 
         [0005]    According to a laparoscopic surgical operation process, small holes are opened in the abdominal region, for example, of a patient, and an endoscope and manipulators or forceps are inserted into such holes. The surgeon performs a surgical operation on the patient with the manipulators or forceps, while watching an image captured by the endoscope and displayed on a display monitor. Since the laparoscopic surgical operation process does not require a laparotomy to be performed, the operation is less burdensome on the patient and greatly reduces the number of days required for the patient to spend in the hospital before recovering from the operation and being released from the hospital. Therefore, the range of surgical operations in which the endoscopic surgical operation process may be applied is expected to increase. 
         [0006]    As disclosed in Japanese Laid-open Patent Publication No. 2002-102248 and Japanese Laid-open Patent Publication No. 2003-061969, a manipulator system comprises a manipulator and a controller for controlling the manipulator. The manipulator comprises an operating unit, which is manually operated, and a working unit replaceably mounted on the operating unit. 
         [0007]    The working unit comprises a long joint shaft and a distal-end working unit (referred to as an “end effector”) mounted on the distal end of the joint shaft. The operating unit has motors for actuating the working unit through wires. The wires have proximal end portions wound around respective pulleys. The controller energizes the motors of the operating unit to cause the pulleys to move the wires circulatively. 
         [0008]    There has also been proposed a medical robot system for actuating medical manipulators with robot arms (see, for example, U.S. Pat. No. 6,331,181). The medical robot system can be remotely controlled by a master arm, and can be moved in various ways under a programmed control. 
         [0009]    The medical robot system has the robot arms, which can selectively be used depending on the surgical technique required. One of the robot arms incorporates an endoscope therein for capturing an image representing the inside of a body cavity, which is capable of being visually confirmed on a display monitor. 
         [0010]    According to the laparoscopic surgical operation process, it is desirable to provide a wider operative field in the body cavity being operated on of the patient because the wider operative field allows the manipulators to operate with greater freedom in the body cavity. 
         [0011]    The body cavity may contain various organs in addition to the organ as the affected region, which make it difficult to provide a wide operative field in the body cavity. The manipulator on one of the robot arms of medical robot systems may be used as a retractor for retracting an organ or organs other than the affected region to a position out of interference with the surgical operation. 
         [0012]    However, when the organ or organs are retracted by the retractor, the retractor itself may be positioned across the body cavity, and present itself as an obstacle in the operative field. 
       SUMMARY OF THE INVENTION 
       [0013]    It is an object of the present invention to provide a method of using a medical manipulator which is capable of keeping a wide operative field in a body cavity. 
         [0014]    A method of performing a surgical procedure on an affected region in a body cavity according to the invention uses a medical manipulator comprising a rod-shaped member having at least first and second bendable joints provided at separate positions along the length of the rod-shaped member, whereby the rod-shaped member can be bent along its length by bending at the joints, and further comprising a manipulating element provided at a distal end of the rod-shaped member. The method comprises the steps of introducing at least the distal end, and the first and second bendable joints, of the rod-shaped member into the body cavity having the affected region; engaging a body portion in the body cavity, other than the affected region, with the manipulating element; manipulating the body portion other than the affected region, using the manipulating element, so as to increase a spacing around the affected region in the body cavity; and bending at least one of said first and second joints so as to increase a spacing between the rod-shaped member and the affected region in the body cavity. 
         [0015]    According to a further feature of the invention, the manipulating element is a gripper and said step of engaging a body portion with the manipulating element comprises gripping the body portion with the gripper, and wherein said step of manipulating the body portion comprises retracting the gripped body portion away from the affected region. 
         [0016]    According to a yet further feature of the invention, the manipulating element is a pusher and said step of engaging a body portion with the manipulating element comprises engaging the body portion with the pusher and wherein said step of manipulating the body portion comprises pushing the body portion to retract the body portion away from the affected region. 
         [0017]    According to a yet further feature of the invention, the step of bending at least one of said first and second joints so as to increase a spacing between the rod-shaped member and the affected region comprises bending both of said first and second joints. 
         [0018]    According to a yet further feature of the invention, the body portion other than the affected region is elongated, and said first and second joints are bent such that at least a portion of the length of the rod-shaped member between the first and second joints extends approximately parallel to the length of the body portion while the gripper is gripping the body portion. 
         [0019]    According to a yet further feature of the invention, the body portion other than the affected region is an intestine. 
         [0020]    The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which preferred embodiments of the present invention are shown by way of illustrative example. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a perspective view of a medical robot system according to a first embodiment of the present invention; 
           [0022]      FIG. 2  is a side elevational view, partly in cross section, of a manipulator according to the first embodiment of the present invention; 
           [0023]      FIG. 3  is a plan view of a pulley and an arm; 
           [0024]      FIG. 4  is an exploded perspective view of a first intermediate joint; 
           [0025]      FIG. 5  is an exploded perspective view of a second intermediate joint; 
           [0026]      FIG. 6  is a perspective view of a distal-end working unit; 
           [0027]      FIG. 7  is a perspective view of a console; 
           [0028]      FIG. 8  is a view illustrative of a tool coordinate operation mode; 
           [0029]      FIG. 9  is a perspective view of a master arm; 
           [0030]      FIG. 10  is a view illustrative of a bending motion of the first intermediate joint in an intermediate joint operation mode; 
           [0031]      FIG. 11  is a view illustrative of a hypothetical hemisphere used as a reference for bending the first intermediate joint in the intermediate joint operation mode; 
           [0032]      FIG. 12  is a view illustrative of a bending motion of the second intermediate joint according to a first control process in the intermediate joint operation mode; 
           [0033]      FIG. 13  is a view illustrative of a bending motion of the second intermediate joint according to a second control process in the intermediate joint operation mode; 
           [0034]      FIG. 14  is a perspective view showing the manner in which a gripper of the manipulator grips a large intestine; 
           [0035]      FIG. 15  is a perspective view showing the manner in which the gripper of the manipulator retracts the large intestine; 
           [0036]      FIG. 16  is a perspective view showing the manner in which the first intermediate joint is bent; 
           [0037]      FIG. 17  is a perspective view showing the manner in which the second intermediate joint is bent; 
           [0038]      FIG. 18  is a perspective view of a distal-end action unit having a fan-like mechanism; 
           [0039]      FIG. 19  is a schematic view illustrative of a medical robot system according to a second embodiment of the present invention; 
           [0040]      FIG. 20  is a schematic view illustrative of a medical robot system according to a third embodiment of the present invention; and 
           [0041]      FIG. 21  is a schematic perspective view of a console of the medical robot system according to the third embodiment. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0042]    Like or corresponding parts shall be denoted by like or corresponding reference characters throughout the views. 
         [0043]    A medical manipulator and a medical robot system to be used according to embodiments of the present invention will be described below with reference to  FIGS. 1 through 21 . 
         [0044]    As shown in  FIG. 1 , a medical manipulator  10   c  and a medical robot system  12  according to a first embodiment of the present invention are particularly suitable for performing a laparoscopic surgical operation on a patient  14 . 
         [0045]    The medical robot system  12  comprises a station  16  disposed near a surgical bed  15 , four robot arms  18   a ,  18   b ,  18   c ,  18   d  mounted on the station  16 , and a console (controller)  20  for controlling the medical robot system  12  in its entirety. The robot arm  18   c  will also be referred to as a first robot arm, and the robot arm  18   d  as a second robot arm. The robot arms  18   a  through  18   d  and the console  20  may be connected to each other by a communication means comprising a wired link, a wireless link, a network, or a combination thereof. The console  20  is not required to control the medical robot system  12  in its entirety, but the robot arms  18   a  through  18   d  may be feedback-controlled by internal controllers combined with the medical robot system  12 . The robot arms  18   a  through  18   c  may be actuated under the control of the console  20  for being operated according to automatic programmed operations or may be manually actuated by respective joysticks  80   a ,  80   b ,  80   c  on the console  20 . The robot arms  18   a  through  18   d  also may be actuated through a combination of automatic programmed operations and manually controlled operations. 
         [0046]    The robot arms  18   a  through  18   c  have manipulators  10   a ,  10   b ,  10   c  disposed respectively on distal ends thereof. The robot arm  18   d  has an endoscope  24  on the distal end thereof. The manipulators  10   a  through  10   c  and the endoscope  24  are inserted into a body cavity  27  of the patient  14  through respective trocars  25 . The station  16  may comprise a plurality of stations supporting the respective robot arms  18   a  through  18   d . The manipulators  10   a  through  10   c  and the endoscope  24  are removably mounted onto the respective robot arms  18   a  through  18   d.    
         [0047]    Each of the robot arms  18   a  through  18   d  has an articulated mechanism, e.g., a mechanism with six independent axes. The robot arms  18   a  through  18   d  are controlled by the console  20 , so as to set the manipulators  10   a  through  10   c  and the endoscope  24  at arbitrary postures and at arbitrary positions, within the operating ranges of the robot arms  18   a  through  18   d . The robot arms  18   a  through  18   c  have respective joint mechanisms including rotary mechanisms  22  for rotating the manipulators  10   a  through  10   c  about respective joints shafts (rod-shaped members)  44 . 
         [0048]    The robot arms  18   a  through  18   d  have respective slide mechanisms  26  for moving the manipulators  10   a  through  10   c  and the endoscope  24  back and forth along the axes defined by the distal ends thereof, and respective lifting and lowering mechanisms  28 , which are movable vertically along the station  16 . The robot arms  18   a  through  18   d  may be structurally identical to each other, or may have different structures depending on the types of manipulators  10   a  through  10   c  and the endoscope  24  that are utilized. 
         [0049]    The manipulators  10   a ,  10   b  mounted respectively on the robot arms  18   a ,  18   b  serve to perform direct surgical techniques on an affected region of the patient  14 . A gripper, scissors, an electrosurgical knife, for example, are mounted onto distal-end working units of the manipulators  10   a ,  10   b . The manipulator  10   c  mounted on the robot arm  18   c  comprises a retractor for retracting an organ in a body cavity  27  or the like to a given place to allow the surgeon to have a wider operative field. 
         [0050]    Further structural details of the manipulator  10   c  and a joint between the manipulator  10   c  and the robot arm  18   c  will be described below. As shown in  FIGS. 2 through 6 , it is assumed that directions established with respect to the manipulator  10   c  include X directions representing horizontal transverse directions of the manipulator  10   c , Y directions representing vertical transverse directions of the manipulator  10   c , and Z directions representing longitudinal directions of the manipulator  10   c , i.e., a joint shaft (rod-shaped member)  44  thereof. The X directions include an X 1  direction representing a rightward direction as viewed from the front of the manipulator  10   c  and an X 2  direction representing a leftward direction as viewed from the front of the manipulator  10   c . The Y directions include a Y 1  direction representing an upward direction and a Y 2  direction representing a downward direction. The Z directions include a Z 1  direction representing a forward direction and a Z 2  direction representing a rearward direction. 
         [0051]    As shown in  FIG. 2 , the manipulator  10   c  is removably mounted on a slider  40 , which is disposed on the distal end of the robot arm  18   c . The slider  40  is slidable by the slide mechanism  26 . The slider  40  supports seven motors  30   a ,  30   b ,  30   c ,  30   d ,  30   e ,  30   f ,  30   g  mounted therein in an array along the Z directions. The motors  30   a  through  30   c  (first actuator) serve to actuate a distal-end working unit  46 , and the motors  30   d  through  30   g  (second actuator) serve to actuate a first intermediate joint  58  and a second intermediate joint  60 . 
         [0052]    The manipulator  10   c  comprises a connecting block  42  for connection to the slider  40 , a hollow joint shaft  44  extending from the connecting block  42  in the Z 1  direction, and a distal-end working unit  46  mounted on the distal end of the joint shaft  44 . 
         [0053]    The connecting block  42  is removably and replaceably mounted on the slider  40  by a removable mounting mechanism. The connecting block  42  supports pulleys  48   a ,  48   b ,  48   c ,  48   d ,  48   e ,  48   f ,  48   g  mounted thereon in an array along the Z directions and held in engagement with the respective motors  30   a  through  38   g . The motors  30   a  through  30   g  or the pulleys  48   a  through  48   g  have noncircular teeth, while the pulleys  48   a  through  48   g  or the motors  30   a  through  30   g  have noncircular recesses. The noncircular teeth engage with the respective noncircular recesses for transmitting rotation of the motors  30   a  through  30   g  to the pulleys  48   a  through  48   g.    
         [0054]    Wires  50   a ,  50   b ,  50   c ,  50   d ,  50   e ,  50   f ,  50   g  are wound respectively around the pulleys  48   a  through  48   g . The wires  50   a  through  50   c  (first flexible member) are annular in shape, wherein portions thereof are fixed to the pulleys  48   a  through  48   c  for preventing slippage on the pulleys  48   a  through  48   c . The wires  50   a  through  50   c  are wound in 1.5 turns around the pulleys  48   a  through  48   c , and extend in the Z 1  direction inside the joint shaft  44 . When the pulleys  48   a  through  48   c  are rotated about their own axes by the motors  30   a  through  30   c , one of the two left and right turns of each of the wires  50   a  through  50   c  is wound around the pulley, and the other turn is paid out from the pulley. The wires  50   a  through  50   c  are spaced from each other in the Y directions so as to be held out of interference with each other. 
         [0055]    The pulleys  48   e ,  48   g  have respective winding members  52  around which the wires  50   e ,  50   g  (second flexible member) are wound. The connecting block  42  houses therein pairs of idlers  54   a ,  54   b  for guiding the wires  50   e ,  50   g  from the winding members  52  to the joint shaft  44 . The idlers  54   a ,  54   b  in the pairs are disposed in obliquely upward and downward positions that are spaced from the winding members  52  of the pulleys  48   e ,  48   g  in directions between the Z 1  and Y 1  directions and between the Z 1  and Y 2  directions, for guiding the wires  50   e ,  50   g  to upper and lower positions above and below the central axis of the joint shaft  44 . When the pulleys  48   e ,  48   g  are rotated about their own axes by the motors  30   e ,  30   g , one of the two upper and lower turns of each of the wires  50   e ,  50   g  is wound around the pulley, and the other turn is paid out from the pulley. 
         [0056]    As shown in  FIG. 3 , the pulley  48   d  has an arm  56  extending in the X directions, and the wire  50   d  has opposite ends connected to the respective ends of the arm  56 . When the pulley  48   d  is rotated about its own axis by the motor  30   d , one of the two left and right turns of the wire  50   d  is wound in, and the other turn is wound off. Although not shown, the pulley  48   f  and the wire  50   f  are of a structure identical to the pulley  48   d  and the wire  50   d . As the wires  50   d ,  50   f  (second flexible member) are not wound around the pulleys  48   d ,  48   f , the pulleys  48   d ,  48   f  do not operate as pulleys, but are referred to as pulleys for the sake of convenience. 
         [0057]    As shown in  FIG. 2 , the joint shaft  44  extends from the connecting block  42  in the Z 1  direction, and the distal-end working unit  46  is mounted on the distal end of the joint shaft  44 . The joint shaft  44  has a first intermediate joint  58  and a second intermediate joint  60  which are successively spaced from the distal end thereof. The first intermediate joint  58  and the second intermediate joint  60  are bent when the wires  50   d  through  50   g  are displaced back and forth in the joint shaft  44 . The first intermediate joint  58  may be located in any position (distance L 1  in  FIG. 2 ) within a range from 3 cm to 5 cm from the distal end of the joint shaft  44  including the distal-end working unit  46 . The second intermediate joint  60  may be located in any position (distance L 2  in  FIG. 2 ) within a range from 7 cm to 12 cm from the distal end of the joint shaft  44  including the distal-end working unit  46 . With the first intermediate joint  58  and the second intermediate joint  60  being thus positioned, the manipulator  10   c  suitably operates as a retractor in surgical techniques (see  FIGS. 14 through 17 ) inside the body cavity  27 . 
         [0058]    As shown in  FIG. 4 , the first intermediate joint  58  comprises a stacked array of joint rings  62  that are angularly movable with respect to each other. In  FIG. 4 , the first intermediate joint  58  is shown as comprising three joint rings  62 . However, the number of joint rings  62  is not limited to three, and the first intermediate joint  58  may comprise a suitable number of joint rings  62 , e.g.,  4  through  30  joint rings  62 . 
         [0059]    Each of the joint rings  62  has a pair of V-shaped grooves  64  defined in one surface thereof in diametrically opposite relation to each other across the center of the joint ring  62 , and also has a pair of semicylindrical ridges  66  disposed on the other surface thereof in diametrically opposite relation to each other across the center of the joint ring  62 . The grooves  64  and the ridges  66  are angularly spaced 90° from each other. Adjacent two of the joint rings  62  are arranged such that their pairs of grooves  64  are angularly spaced 90° from each other, and are also joined to each other such that the ridges  66  of one of the joint rings  62  are inserted in the respective grooves  64  of the other joint ring  62 . 
         [0060]    Each of the joint rings  62  has four through holes  67  defined therein at positions of the grooves  64  and the ridges  66 . The wires  50   d ,  50   e  extend respectively through the through holes  67  in the joint rings  62  and have respective tip ends coupled to the joint ring  62  at the distal end side of the first intermediate joint  58  in the Z 1  direction. The joint rings  62  are joined together into a substantially integral assembly. 
         [0061]    With the ridges  66  being inserted in the respective grooves  64 , gaps are left between the adjacent ones of the joint rings  62 , allowing the ridges  66  to being angularly moved in the respective grooves  64 . Therefore, the adjacent ones of the joint rings  62  can be angularly moved with respect to each other. Although the joint rings  62  of each adjacent pair are angularly movable through a small angle with respect to each other, the sum of the angles through which the joint rings  62  of all adjacent pairs are angularly movable is large enough to allow the first intermediate joint  58  to be bent through a desired angle, for example, in the range from about 60° to 120°. Accordingly, the distal-end working unit  46  can be bent into an orientation not parallel to the longitudinal axis of the joint shaft  44 . 
         [0062]    When the pulleys  48   d ,  48   e  are rotated a given angle about their own axes under the control of the console  20 , the wires  50   d ,  50   e  are displaced back and forth by the corresponding distance for thereby bending the first intermediate joint  58  through a desired angle vertically and horizontally in a plane transverse to the joint shaft  44 . In other words, the first intermediate joint  58  is bent or curved actively by being pulled by the wires  50   d ,  50   e . The first intermediate joint  58  may be bent in desired directions and with a desired degree of freedom. Although not shown, the outer circumferential surface of each of the joint rings  62  may be covered with a layer made of an elastic or flexible material. 
         [0063]    Each of the joint rings  62  has a central guide plate  70  having six guide holes  68  defined therein, through which the wires  50   a ,  50   b ,  50   c  extend. The six guide holes  68  are arranged in three pairs spaced apart in the Y directions, and are arrayed in two vertical rows spaced apart in the X directions. The six guide holes  68  are clustered near the central axis of the guide plate  70 . When the first intermediate joint  58  is not bent, the wires  50   a ,  50   b ,  50   c  extending through the guide holes  68  are not bent, but extend straight. Although the joint rings  62  are shown as having the respective guide plates  70 , at least one of the joint rings  62  may have a central guide plate  70 . 
         [0064]    When the first intermediate joint  58  is bent, the wires  50   a  though  50   c  are guided through the guide holes  68  against being unduly displaced or bent, and are held out of contact with each other and remain in respective appropriate positions. 
         [0065]    As shown in  FIG. 5 , the second intermediate joint  60  is essentially identical in structure to the first intermediate joint  58 , and comprises a stacked array of joint rings  62  each having four additional through holes  72  defined respectively adjacent to the four through holes  67 . The wires  50   f ,  50   g  extend respectively through the through holes  67  in the joint rings  62 , and act in the same manner as the wires  50   d ,  50   e  in the first intermediate joint  58 , for actively bending or curving the second intermediate joint  60 . The wires  50   d ,  50   e  extend respectively through the through holes  72  and further extend toward the first intermediate joint  58  in the Z 1  direction. 
         [0066]    The first intermediate joint  58  and the second intermediate joint  60  are covered with respective bellows-like or flexible and bendable sheaths. The other portion of the joint shaft  44  than the first intermediate joint  58  and the second intermediate joint  60  is made of a hard material. 
         [0067]    As shown in  FIG. 6 , the distal-end working unit  46  is mounted on the distal end of the joint shaft  44 , and comprises at least a pulley (rotor) around which the wire  50   a  is wound, a pulley around which the wire  50   b  is wound, and a pulley around which the wire  50   c  is wound. When the wires  50   a ,  50   b ,  50   c  are moved back and forth upon rotation of the pulleys  48   a ,  48   b ,  48   c  in the connecting block  42 , the pulleys in the distal-end working unit  46  are driven to rotate, causing the distal-end working unit  46  to move about three axes. The motions of the distal-end working unit  46  include angular motions about a pitch axis (distal-end joint)  74  and a yaw axis (distal-end joint)  75  and opening and closing motions of a gripper  78 , for example. The gripper  78  comprises a pair of gripper arms, one or both of which are openable. The distal-end working unit  46  may be of the same mechanism as the distal-end working unit of the medical manipulator disclosed in Japanese Laid-Open Patent Publication No. 2003-061969, for example. 
         [0068]    Since the first intermediate joint  58 , the second intermediate joint  60 , the pitch axis  74 , the yaw axis  75 , and the gripper  78  can possibly cause a mutual interference, the console  20  calculates an amount of interference and controls the wires  50   a  through  50   g  to move back and forth to compensate for an interfering movement. In other words, the console  20  controls the wires  50   a  through  50   g  such that when it moves one of the movable members, it prevents the other from unnecessarily moving due to such an interfering movement. 
         [0069]    The manipulators  10   a ,  10   b  may be of a structure which is free from the first intermediate joint  58 , the second intermediate joint  60 , the motors  30   d  through  30   f , the wires  50   d  through  50   f , and the pulleys  48   d  through  48   f  of the manipulator  10   c , and which is otherwise the same as the manipulator  10   c . Alternatively, the manipulators  10   a ,  10   b  may be structurally identical to the manipulator  10   c.    
         [0070]    As shown in  FIG. 7 , the console  20  has three joysticks  80   a ,  80   b ,  80   c  as manual control units, a display monitor  82  (see  FIG. 1 ), two trackballs (rotary input means)  84   a ,  84   b , enable switches  86   a ,  86   b  for enabling or disabling input actions of the trackballs  84   a ,  84   b , and return switches  88   a ,  88   b . The display monitor  82  displays information about an endoscopic image captured by the endoscope  24  and other information. The trackballs  84   a ,  84   b  are spaced from each other at a central area on the upper surface of the control table of the console  20 . The return switches  88   a ,  88   b  are disposed behind the respective trackballs  84   a ,  84   b . The enable switches  86   a ,  86   b  comprise arcuately-shaped momentary switches disposed around respectively partly circumferential surfaces of the trackballs  84   a ,  84   b.    
         [0071]    The operator can operate the joysticks  80   a ,  80   b ,  80   c  to move the robot arms  18   a ,  18   b ,  18   c  individually. The robot arm  18   d  can be operated by another input means, not shown. The joysticks  80   a ,  80   b  are positioned at respective left and right positions where they can easily be operated by the operator. The joystick  80   c  is positioned in a central position behind the joysticks  80   a ,  80   b.    
         [0072]    The joysticks  80   a ,  80   b ,  80   c  are vertically movable, twistable, and tiltable in all directions for moving the robot arms  18   a ,  18   b ,  18   c  according to the joystick motions. When the joysticks  80   a ,  80   b ,  80   c  are released from the hands of the operator, they automatically return to their upright reference orientations shown in  FIG. 7  with the robot arms  18   a ,  18   b ,  18   c  being kept in their displaced positions. The joysticks  80   a ,  80   b ,  80   c  are basically identical in structure to each other, and have a handle grip  100  which is gripped by a human hand, a trigger lever  102  which is pushed and pulled mainly by an index finger and a middle finger, and a composite input pad  104  which is gripped mainly by a thumb. When the trigger lever  102  is operated, the gripper  78  is opened and closed. The composite input pad  104  includes horizontal and vertical see-saw switches  104   a ,  104   b  disposed centrally thereof in a crisscross pattern. When the horizontal see-saw switch  104   a  is operated, the distal-end working unit  46  is tilted about the yaw axis  75 , and when the vertical see-saw switch  104   b  is operated, the distal-end working unit  46  is tilted about the pitch axis  74 . 
         [0073]    The robot arms  18   a ,  18   b ,  18   c  can be operated in an absolute coordinate (world coordinate) operation mode and a tool coordinate operation mode, for example. 
         [0074]    In the absolute coordinate operation mode, the manipulator  10   c  coacts with the robot arm  18   c  (including the slide mechanism  26 ) connected thereto based on an input action of the joystick  80   c . At this time, the position of the distal-end working unit  46  is set based on absolute coordinates depending on the movement of the handle grip  100 , and the orientation of the distal-end working unit  46  is set based on input actions of the see-saw switches  104   a ,  104   b.    
         [0075]    In the tool coordinate operation mode, the manipulator  10   c  coacts with the robot arm  18   c  (including the slide mechanism  26 ) connected thereto based on an input action of the joystick  80   c , for moving the distal-end working unit  46  back and forth in a constant posture based on a tool coordinate system according to the posture of the distal-end working unit  46 . 
         [0076]    For example, as shown in  FIG. 8 , according to the posture of the distal-end working unit  46  at the time, a tool coordinate system having orthogonal axes Zt 0 , Xt 0 , Yt 0  (the axis Yt 0  is omitted from illustration) is established, and the distal-end working unit  46  is operated based on the established tool coordinate system. The distal-end working unit  46  is moved from an imaginary-line position to a solid-line position while the gripper  78  is extending along the coordinate axis Zt 0 . At this time, the position of a hypothetical reference point P 1  at the trocar  25  (pivot point) and the posture of the distal-end working unit  46  are kept constant. 
         [0077]    The joysticks  80   a ,  80   b ,  80   c  may be replaced with a master arm  200  shown in  FIG. 9 . 
         [0078]    As shown in  FIG. 9 , the master arm  200  comprises a pivot shaft  202 , a first U-shaped member  204 , a second U-shaped member  206 , and a pair of tongue members  208 . The first U-shaped member  204  is open upwardly and rotatably mounted on the upper end of the pivot shaft  202  for rotation in a horizontal plane. The angle through which the first U-shaped member  204  is rotated with respect to the pivot shaft  202  is detected by a rotation sensor  210  and reflected in the motion of the distal-end working unit  46  about the yaw axis  75 . 
         [0079]    The second U-shaped member  206  is smaller in size than the first U-shaped member  204 , and is disposed in the first U-shaped member  204 . The first U-shaped member  204  and the second U-shaped member  206  have their ends rotatably connected to each other. The second U-shaped member  206  is rotatable in a vertical plane with respect to the first U-shaped member  204 . The angle through which the second U-shaped member  206  is rotated with respect to the first U-shaped member  204  is detected by a rotation sensor  212  and reflected in the motion of the distal-end working unit  46  about the pitch axis  74 . 
         [0080]    The tongue members  208  are rotatably mounted on an intermediate portion of the second U-shaped member  206  by a shaft  214 . The angle through which the shaft  214  is rotated with respect to the second U-shaped member  206  is detected by a rotation sensor  216  and reflected in the operation of the rotary mechanisms  22  (see  FIG. 1 ). 
         [0081]    The tongue members  208  are openable and closable with respect to, i.e., movable toward and away from, each other about the shaft  214 . The angle through which the tongue members  208  are opened or closed with respect to each other is detected by an internal sensor  218  and reflected in the opening and closing motion of the gripper  78 . 
         [0082]    The master arm  200  is displaceable as a whole in the X, Y, and Z directions shown in  FIG. 9 . The positions of the master arm  200  in the X, Y, and Z directions with respect to the console  20  can be detected by a sensor, not shown. The master arm  200  may be tilted in the X and Y directions with respect to the console  20  by tilting mechanisms. The detected position of the master arm  200  in the X, Y, and Z directions with respect to the console  20  are reflected in the absolute coordinates of the distal-end working unit  46 . The master arm  200  is thus capable of indicating six parameters with respect to the position and orientation of the distal-end working unit  46 , and also of instructing the gripper  78  to be opened and closed. 
         [0083]    When the master arm  200  is released from the operator&#39;s hands, the master arm  200  may be returned to its home position shown in  FIG. 9  under the bias of resilient members, not shown, with the robot arms  18   a ,  18   b ,  18   c  being kept in their displaced positions. 
         [0084]    In the tool coordinate operation mode, the distal-end working unit  46  may be moved along another coordinate axis Zt or in directions along the coordinate axis Zt or in a combination of those directions. In the tool coordinate operation mode, when the master arm  200  is operated, the directions in which the distal-end working unit  46  moves laterally, i.e., the X directions in  FIG. 9 , correspond to a coordinate axis Xt, the directions in which the distal-end working unit  46  moves back and forth, i.e., the Y directions in  FIG. 9 , correspond to a coordinate axis Yt, and the directions in which the distal-end working unit  46  moves vertically, i.e., in the Z directions in  FIG. 9 , correspond to a coordinate axis Zt. 
         [0085]    In the tool coordinate operation mode, the posture of the robot arm  18   c  may be determined by setting the position and posture of the distal-end working unit  46 , defining the position of the hypothetical reference point P 1 , and performing known matrix transform calculations. The distal-end working unit  46  may also be operated in the tool coordinate operation mode with the joystick  80   c  or the master arm  200 . 
         [0086]    In the tool coordinate operation mode, the distal-end working unit  46  can easily be operated to retract an organ in the body cavity  27 . 
         [0087]    The trackball  84   a  serves as an input means for operating the first intermediate joint  58  of the manipulator  10   c.    
         [0088]    Based on an input action of the trackball  84   a  in an intermediate joint operation mode, the manipulator  10   c  coacts with the robot arm  18   c  (including the slide mechanism  26 ) connected thereto to bend the first intermediate joint  58  with the distal-end working unit  46  being kept in constant position and posture. 
         [0089]    For example, as shown in  FIG. 10 , there is assumed a sphere (hypothetical spherical surface)  110  defined around the position P 2  of the distal-end joint (the pitch axis  74  and the yaw axis  75 ) of the distal-end working unit  46  at the time, the sphere  110  having a radius equal to the distance r 1  from the position P 2  to the first intermediate joint  58 , and the first intermediate joint  58  (indicated by a point P 3  in  FIGS. 10 and 11 ) is moved along the surface of the sphere  110  from an imaginary-line position to a solid-line position. At this time, the position of the hypothetical reference point P 1  at the trocar  25  and the position and posture of the distal-end working unit  46  are kept constant. 
         [0090]    If the first intermediate joint  58  can be bent either vertically or laterally only, then the first intermediate joint  58  may be moved along a given hypothetical arc instead of the sphere  110 . 
         [0091]    In the intermediate joint operation mode, as shown in  FIG. 11 , orthogonal coordinate axes Xp, Yp extending across the first intermediate joint  58  along the sphere  110  are established based on the orientation of the distal-end working unit  46  or the orientation of the overall manipulator  10   c  at the time. At this time, when the trackball  84   a  is operated, the directions in which it is angularly moved laterally correspond to the coordinate axis Xp, and the directions in which it is angularly moved back and forth correspond to the coordinate axis Yp. The first intermediate joint  58  is also bendable in all directions other than the coordinate axes Xp, Yp. When the trackball  84   a  is angularly moved in a given direction, the first intermediate joint  58  is bent depending on the direction in which the trackball  84   a  is angularly moved and the angular amount by which the trackball  84   a  is angularly moved. When the trackball  84   a  is stopped, the first intermediate joint  58  stops being bent. When the first intermediate joint  58  reaches a limit of its bending range in a given direction, a bending command for bending the first intermediate joint  58  further in that direction is disabled. 
         [0092]    In the intermediate joint operation mode, another rotary input means may be employed rather than the trackball  84   a . For example, the joystick  80   c  may be employed such that the directions in which it is tilted laterally correspond to the coordinate axis Xp and the directions in which it is tilted back and forth correspond to the coordinate axis Yp. 
         [0093]    In the intermediate joint operation mode, the posture of the robot arm  18   c  may be determined by setting the position and posture of the distal-end working unit  46 , defining the positions of the hypothetical reference point P 1  and the first intermediate joint  58 , and performing known matrix transform calculations. 
         [0094]    For operating the first intermediate joint  58 , the enable switch  86   a  is pressed to enable the trackball  84   a . If the enable switch  86   a  is not pressed, then the trackball  84   a  remains disabled, and the first intermediate joint  58  is prevented from being moved when the trackball  84   a  is operated carelessly. 
         [0095]    When the return switch  88   a  is pressed, the first intermediate joint  58  automatically returns to a zero-bend-angle state (see  FIG. 2 ) at a predetermined speed. With the first intermediate joint  58  in the zero-bend-angle state, the joint shaft  44  can easily be pulled out of the trocar  25 . The return switch  88   a  is a momentary switch which is enabled only when it is pressed. When the return switch  88   a  is released, the returning motion of the first intermediate joint  58  is interrupted, allowing the operator to confirm the state of the first intermediate joint  58 . 
         [0096]    In the intermediate joint operation mode, the second intermediate joint  60  can also be bent by the trackball  84   b , the enable switch  86   b , and the return switch  88   b . The trackball  84   b , the enable switch  86   b , and the return switch  88   b  operate in the same manner as the trackball  84   a , the enable switch  86   a , and the return switch  88   a.    
         [0097]    The second intermediate joint  60  can be controlled according to a plurality of control processes, which can be selected. According to a first control process, as shown in  FIG. 12 , there is assumed a sphere  112  around the first intermediate joint  58 , the sphere  112  having a radius equal to the distance r 2  from the first intermediate joint  58  to the second intermediate joint  60 , and the second intermediate joint  60  is moved along the surface of the sphere  112  from an imaginary-line position to a solid-line position. At this time, the position of the hypothetical reference point P 1  at the trocar  25 , the position and posture of the distal-end working unit  46 , and the position and posture of a link  114  extending from the point P 2  to the first intermediate joint  58  are kept constant. According to the first control process, the first intermediate joint  58  is also bent in coaction with the second intermediate joint  60  as it is bent. 
         [0098]    According to a second control process, as shown in  FIG. 13 , there is assumed a sphere  116  defined around the position P 2  of the distal-end joint (the pitch axis  74  and the yaw axis  75 ) of the distal-end working unit  46  at the time, the sphere  116  having a radius equal to the distance r 3  from the position P 2  to the second intermediate joint  60 , and the second intermediate joint  60  is moved along the surface of the sphere  116  from an imaginary-line position to a solid-line position. At this time, the position of the hypothetical reference point P 1  at the trocar  25  and the position and posture of the distal-end working unit  46  are kept constant. According to the second control process, the first intermediate joint  58  remains bent. 
         [0099]    The first intermediate joint  58  and the second intermediate joint  60  may automatically be moved according to a program or a teaching process, rather than being controlled based on the operation of the trackballs  84   a ,  84   b.    
         [0100]    Operation of the manipulator  10   c  and the medical robot system  12  thus constructed will be described below. 
         [0101]    First, a gas is introduced around the affected region of the patient to form the body cavity  27 , and the distal-end working units  46  and the joint shaft  44  of the manipulator  10   c  are inserted through the trocar  25 . The state in the body cavity  27  is confirmed based on an endoscopic image captured by the endoscope  24  that has been inserted into the body cavity  27 . 
         [0102]    Prior to a surgical technique to be performed on an affected region  118 , other organs that exist around the affected region  118  are retracted to given regions to provide a wide operative field in the body cavity  27 . 
         [0103]    For example, as shown in  FIG. 14 , for retracting a large intestine  120 , the distal-end working unit  46  is bent around the pitch axis  74  and the yaw axis  75  into an orientation substantially perpendicularly to an appropriate portion of the large intestine  120 . Thereafter, the gripper  78  grips the large intestine  120  lightly. 
         [0104]    Then, as shown in  FIG. 15 , the distal-end working unit  46  is moved forward to retract the large intestine  120  to a deeper region. At this time, in order to keep the distal-end working unit  46  and the gripped portion of the large intestine  120  oriented relatively to each other, the distal-end working unit  46  may be pushed in the direction of a coordinate axis Zt 1  in the tool coordinate operation mode (see  FIG. 8 ). 
         [0105]    By thus retracting the large intestine  120 , the large intestine  120  is sufficiently spaced from the affected region  118 , allowing the surgeon to perform a surgical operation on the affected region  118 . The manipulator  10   c  thus acts as a retractor. In some instances, even when the large intestine  120  is retracted away from the affected region  118  by the manipulator  10   c , the manipulator  10   c  may be positioned across the body cavity  27 , failing to provide a wide operative field in the body cavity  27 . 
         [0106]    To avoid the above difficulty, at least one of the first intermediate joint  58  and the second intermediate joint  60  of the manipulator  10   c  is bent. 
         [0107]    For example, as shown in  FIG. 16 , in the intermediate joint operation mode, the first intermediate joint  58  is bent to make the link  114  substantially parallel to the large intestine  120 . Thus, the joint shaft  44  is spaced from the affected region  118 , providing a wide operative field  122  around the affected region  118 . The surgeon finds it easy to perform a surgical procedure on the affected region  118  with the other manipulators  10   a ,  10   b . As a result, the time required to perform the surgical operation may be shortened. 
         [0108]    Although the wide operative field  122  is provided simply by bending the first intermediate joint  58 , the second intermediate joint  60  may instead be bent to provide a wider operative field  124 , as shown in  FIG. 17 . For bending the second intermediate joint  60 , one or both of the first control process (see  FIG. 12 ) and the second control process (see  FIG. 13 ) may be carried out. 
         [0109]    In this case, it is assumed that the distal-end working unit  46  has an axis S 1 , the link  114  has an axis S 2 , and a link  129  extending from the first intermediate joint  58  to the second intermediate joint  60  has an axis S 3 . The second intermediate joint  60  may be bent such that the axes S 2 , S 3  are held in alignment with each other. 
         [0110]    For retracting the large intestine  120 , it may not be gripped by the gripper  78 , but may be engaged and pushed by a distal-end action unit  130  (see  FIG. 18 ) having a folding-fan-like mechanism. The distal-end action unit  130  may comprise a membrane extending between two openable gripper arms. Since the distal-end action unit  130  does not grip the large intestine  120 , it is less detrimental to the large intestine  120 . When the distal-end action unit  130  is folded by closing the openable gripper arms, it can easily be inserted through the trocar  25 . 
         [0111]    With the manipulator  10   c  according to the present embodiment, the gripper  78  can be adjusted in orientation about the pitch axis  74  and the yaw axis  75  of the distal-end joint for performing an appropriate surgical procedure on the affected region. If the manipulator  10   c  is used as a retractor, then the gripper  78  can appropriately be oriented to an organ such as the large intestine  120 . Furthermore, since the joint shaft  44  of the manipulator  10   c  can be bent at the first intermediate joint  58  and the second intermediate joint  60 , the joint shaft  44  can be appropriately placed around the affected region to provide a wide operative field in the body cavity  27 . Particularly, the bendable joint shaft  44  is preferable to avoid physical interference with the other manipulators  10   a ,  10   b  in the body cavity  27 . 
         [0112]    The manipulator  10   c  is connected to the robot arm  18   c , and the robot arm  18   c  coacts with the manipulator  10   c  to move the manipulator  10   c  back and forth and tilt the manipulator  10   c  with respect to the reference point P 1  at the trocar  25  for achieving appropriate manipulator motions. 
         [0113]    With the medical robot system  12  according to the present embodiment, the manipulator  10   c  is used to retract an organ or organs in the body cavity  27  to a given region to provide a wide operative field in the body cavity  27 . Inasmuch as the joint shaft  44  is bendable at the first intermediate joint  58  and the second intermediate joint  60 , the joint shaft  44  can appropriately be positioned in the body cavity  27  to provide a wider operative field in the body cavity  27  and also to avoid physical interference with the other manipulators  10   a ,  10   b  for allowing the surgeon to perform a surgical procedure with ease. 
         [0114]    The first intermediate joint  58  and the second intermediate joint  60  are movable on a hypothetical sphere or a hypothetical arc around a given reference point depending on the angular amount by which and the direction in which the trackballs  84   a ,  84   b  are angularly moved. The trackballs  84   a ,  84   b  allow the operator to bend the first intermediate joint  58  and the second intermediate joint  60  appropriately with ease and also intuitively in a manner to fit the feeling of the operator. 
         [0115]      FIG. 19  is a schematic view illustrative of a medical robot system according to a second embodiment of the present invention.  FIG. 19  shows manipulators  10   d ,  10   e  and an endoscope  24 , which are constituent elements of the medical robot system. 
         [0116]    The medical robot system according to the second embodiment differs from the medical robot system  10  according to the first embodiment in that the manipulator  10   d  having a different structure from the manipulator  10   a  is provided at the distal end of the robot arm  18   a  and the manipulator  10   e  having a different structure from the manipulator  10   b  is provided at the distal end of the robot arm  18   b.    
         [0117]    A rod-shaped member  44   d  of the manipulator  10   d  has an intermediate joint  60   d  in an intermediate portion thereof, and a rod-shaped member  44   e  of the manipulator  10   e  has an intermediate joint  60   e  in an intermediate portion thereof. The intermediate joints  60   d ,  60   e  have the same structure as the first intermediate joint  58  shown in  FIGS. 2 and 4 . More specifically, the manipulators  10   d ,  10   e  have such a structure that the second intermediate joint  60  is eliminated from the manipulator  10  shown in  FIG. 2 . In the structure shown in  FIG. 19 , an end effector provided at the distal end of the manipulator  10   d  is configured as scissors  79 , and an end effector provided at the distal end of the manipulator  10   e  is configured as a gripper  78 . 
         [0118]    The manipulators  10   d ,  10   e  can be operated using operation input means shown in  FIG. 7 . More specifically, an operator operates joysticks (first and second input means)  80   a ,  80   b  to move and open/close distal-end working units  76   d ,  76   e  of the manipulators  10   d ,  10   e  and change the posture thereof. Further, the operator can operate trackballs  84   a ,  84   b  to move the intermediate joints  60   d ,  60   e . Incidentally, the trackballs  84   a ,  84   b  may be omitted. In this case, a switch may be provided to select an object(s) to be operated, and the operator may operate the joysticks  80   a ,  80   b  to move the intermediate joints  60   d ,  60   e.    
         [0119]    As shown in  FIG. 19 , the manipulators  10   d ,  10   e  and the endoscope  24  are inserted into a body cavity  27  of a patient  14  through a common trocar supporting member  125 . The operator captures images of an affected region and its peripheral portions with the endoscope  24 , while performs a given surgical procedure on the affected region with the end effectors (gripper  78  and scissors  79 ) provided at the distal end of the manipulators  10   d ,  10   e . That is, the medical robot system according to the second embodiment enables the operator to perform a surgical procedure by single port access. 
         [0120]    More specifically, the trocar supporting member  125  has a plurality of holes (three holes in the present embodiment), into which the trocars  25   a  to  25   c  are hermetically inserted, respectively. The trocars  25   a ,  25   b  are adapted for the manipulators  10   d ,  10   e , whereas the trocar  25   c  is adapted for the endoscope  24 . If the outer diameter of the rod-shaped members  44   d ,  44   e  of the manipulators  10   d ,  10   e  has the same size as the inner diameter of the endoscope  24 , the trocars  25   a ,  25   b  and the trocar  25   c  may have the same structure. 
         [0121]    A laparoscopic surgical operation process is performed using the medical robot system according to the second embodiment by single port access in the following manner. First, the trocar supporting member  125  is inserted into the patient  14 . Next, the trocars  25   a ,  25   b  for the manipulators  10   d ,  10   e  and the trocar  25   c  for the endoscope  24  are inserted into the trocar supporting member  125 . Then, the two manipulators  10   d ,  10   e  and the endoscope  24  are inserted into the body cavity  27  of the patient  14  through the trocars  25   a ,  25   b ,  25   c , respectively. In this case, as shown in  FIG. 19 , the rod-shaped members  44   d ,  44   e  of the manipulators  10   d ,  10   e  are straightened, and then they are inserted such that the rod-shaped members  44   d ,  44   e  intersect with each other. 
         [0122]    After the rod-shaped members  44   d ,  44   e  are inserted to a certain extent, the intermediate joints  60   d ,  60   e  are bent in such a direction that the end effectors (gripper  78  and scissors  79 ) approach each other. Next, an observing point of the endoscope  24  is secured in order that images of a portion to be treated and the distal-end working units  76   d ,  76   e  can be captured with the endoscope  24 . Then, the operator performs a given surgical procedure on the portion to be treated, with the end effectors. In a surgical example shown in  FIG. 19 , a tissue  121  within the body cavity  27  is gripped with the gripper  78 , while a membranous tissue  140  near the tissue  121  is cut out with the scissors  79 . 
         [0123]    With the medical robot system according to the second embodiment, when a surgical procedure is performed by single port access, the distal-end working units  76  having the end effectors can be moved closer to each other by bending the rod-shaped members  44   d ,  44   e  of the two manipulators  10   d ,  10   e  which intersect with each other at the trocar supporting member  125 , by means of the intermediate joints  60   d ,  60   e . Thus, a surgical procedure by single port access can be performed suitably. 
         [0124]    As shown in  FIG. 19 , when the rod-shaped members  44   d ,  44   e  of the manipulators  10   d ,  10   e  intersect with each other, the proximal end portion of the manipulator  10   d  is located on the left side, while the proximal end portion of the manipulator  10   e  is located on the right side. Accordingly, the positional relation of the proximal end portions is opposite to the positional relation of the distal-end working units  76   d ,  76   e . For easier understanding, the field of view of the endoscope  24  (image captured with the endoscope  24 ), i.e., the area that is displayed on the screen of the monitor  82  (see  FIG. 1 ), is represented by reference character A. As described above, the proximal end of the manipulator  10   d  is located on the left side whereas the distal-end working unit  76   d  of the manipulator  10   d  is located on the right side on the screen of the monitor  82 . Similarly, the proximal end of the manipulator  10   e  is located on the right side whereas the distal-end working unit  76   e  of the manipulator  10   e  is located on the left side on the screen of the monitor  82 . 
         [0125]    If the left joystick  80   a  in  FIG. 7  always serves to operate the left manipulator  10   d  and the right joystick  80   b  always serves to operate the right manipulator  10   e , an operator has to operate the joysticks  80   a ,  80   b  while imagining a positional relation that is left-and-right reverse to the positional relation of the distal-end working units  76   d ,  76   e  on the screen. Accordingly, the operator can not operate the manipulators intuitively. 
         [0126]    Thus, when the manipulators  10   d ,  10   e  are inserted into the body cavity  27  such that the rod-shaped members  44   d ,  44   e  intersect with each other, the console  20  (see  FIG. 1 ) may control operation of the manipulators  10   d ,  10   e  in a left-and-right reverse operation mode to be described below. In the left-and-right reverse operation mode, the console  20  operates the manipulator  10   e  whose distal-end working unit  76   e  is located on the left side on the screen of the monitor  82 , based on input operation of the left joystick  80   a , while the console  20  operates the manipulator  10   d  whose distal-end working unit  76   d  is located on the right side on the screen of the monitor  82 , based on input operation of the right joystick  80   b.    
         [0127]    By setting the left-and-right reverse operation mode, even if the manipulators  10   d ,  10   e  are inserted into the body cavity  27  with the rod-shaped members  44   d ,  44   e  intersecting with each other, the operator can operate the manipulators intuitively in a manner to fit the feeling of the operator, because operation by the left hand of the operator is reflected on the movement of the manipulator  10   e  whose distal-end working unit  76   e  is located on the left side on the screen, and operation by the right hand of the operator is reflected on the movement of the manipulator  10   d  whose distal-end working unit  76   d  is located on the right side on the screen. 
         [0128]    In this case, a switch may be provided onto the console  20 , for enabling/disabling the left-and-right reverse operation mode, and the operator may manually operate the switch to cause the console to control operation of the manipulators in the left-and-right reverse operation mode. 
         [0129]    Alternatively, the console  20  may determine whether the rod-shaped members  44   d ,  44   e  intersect with each other or not, based on the positional coordinates of the manipulators  10   d ,  10   e , and when the console  20  determines that the rod-shaped members  44   d ,  44   e  intersect with each other, the console  20  may automatically set the left-and-right reverse operation mode. In this case, the operator does not need to determine by oneself whether the rod-shaped members  44   d ,  44   e  intersect with each other or not, and burden on the operator is thus reduced. 
         [0130]      FIG. 20  is a schematic view illustrative of a medical robot system according to a third embodiment of the present invention.  FIG. 20  shows manipulators  10   c ,  10   d  and an endoscope  24 , which are constituent elements of the medical robot system. 
         [0131]    The medical robot system according to the third embodiment is a medical robot system in which the manipulator  10   c  (see  FIG. 2 ) of the medical robot according to the first embodiment, instead of the manipulator  10   e , is applied to the medical robot system according to the second embodiment. The manipulator  10   d  that is provided at the distal end of the robot arm  18   a  has the same structure as the manipulator  10   d  according to the second embodiment. 
         [0132]    As described above, the manipulator  10   c  has the first intermediate joint  58  and the second intermediate joint  60 , and accordingly the rod-shaped member  44  can be bent at two points. Thus, the manipulator  10   c  has greater flexibility to its possible shape, compared to the manipulator  10   e  (see  FIG. 19 ). The trocar supporting member  125  and the trocars  25   a  to  25   c  have the same structures as the trocar supporting member  125  and the trocars  25   a  to  25   c  shown in  FIG. 19 , respectively. 
         [0133]    The manipulators  10   c ,  10   d  can be operated by means of operation input means  21  of a console  20   a  shown in  FIG. 21 . The console  20   a  having the operation input means  21  differs from the console  20  shown in  FIG. 7  in that the console  20   a  further comprises two trackballs  84   c ,  84   d  and two enable switches  86   c ,  86   d . More specifically, an operator can operate the joysticks  80   a ,  80   b  to move and open/close distal-end working units  76 ,  76   d  of the manipulators  10   c ,  10   d  and change the posture thereof, and also operate the trackballs  84   a  to  84   d  to actuate the intermediate joint  60   d , the first intermediate joint  58  and the second intermediate joint  60 . 
         [0134]    The console  20   a  can execute the left-and-right reverse operation mode, as with the console  20  according to the second embodiment. Accordingly, when the manipulators  10   c ,  10   d  intersect with each other, the manipulator  10   c  whose distal-end working unit  76  is located on the left side is operated based on input operation by the left joystick  80   a , and the manipulator  10   d  whose distal-end working unit  76   d  is located on the right side is operated based on input operation by the right joystick  80   b . In this case, one (e.g., trackball  84   a  at the back) of the two left trackballs  84   a ,  84   c  serves to operate the first intermediate joint  58 , while the other trackball (e.g., trackball  84   c  at the front) serves to operate the second intermediate joint  60 . Further, one of the two right trackballs  84   b ,  84   d  serves to operate the intermediate joint  60   d.    
         [0135]    When the manipulators  10   c ,  10   d  do not intersect with each other, the manipulator  10   d  is operated based on input operation by the left joystick  80   a , while the manipulator  10   c  is operated based on input operation by the right joystick  80   b . In this case, one of the two left trackballs  84   a ,  84   c  serves to operate the intermediate joint  60   d . Also, one (e.g., trackball  84   b  at the back) of the two right trackballs  84   b ,  84   d  serves to operate the first intermediate joint  58 , and the other trackball (e.g., trackball  84   d  at the front) serves to operate the second intermediate joint  60 . 
         [0136]    Incidentally, as with the operation input means of the console  20  shown in  FIG. 7 , the trackballs  84   a ,  84   b  may be provided on the left side and on the right side, respectively. In this case, a switch may be provided to select an object to be operated based on input operation by each of the trackballs  84   a ,  84   b . For example, the switch may be configured such that the operator can switch between one mode where operation by the trackball  84   a  (or the trackball  84   b ) is reflected on the movement of the intermediate joint  60   d  and anther mode where operations by the trackballs  84   a ,  84   b  are reflected on the movements of the first and second intermediate joints  58 ,  60 , respectively. 
         [0137]    A laparoscopic surgical operation process is performed using the medical robot system according to the third embodiment by single port access in the following manner. First, the trocar supporting member  125  is inserted into the patient  14 . Next, the trocars  25   a ,  25   b  for the manipulators  10   c ,  10   d  and the trocar  25   c  for the endoscope  24  are inserted into the trocar supporting member  125 . Then, the two manipulators  10   c ,  10   d  and the endoscope  24  are inserted into the body cavity  27  of the patient  14  through the trocars  25   a ,  25   b ,  25   c , respectively. In this case, as shown in  FIG. 20 , the rod-shaped members  44 ,  44   d  of the manipulators  10   c ,  10   d  are straightened, and then they are inserted such that the rod-shaped members  44 ,  44   d  intersect with each other. 
         [0138]    After the rod-shaped members  44 ,  44   d  are inserted to a certain extent, the first and second intermediate joints  58 ,  60  of the manipulator  10   c  are bent, so that an organ  142  (obstacle to an operative field) is pushed aside (retracted) with the rod-shaped member  44  (link  114  in  FIG. 20 ) for a wider operative field. After the wider operative field has been thus secured, the intermediate joint  60   d  of the rod-shaped member  44   d  are bent and the first and second intermediate joints  58 ,  60  are further bent so as to move the end effectors closer to each other. 
         [0139]    Next, an observing point of the endoscope  24  is secured in order that images of a portion to be treated and the distal-end working units  76 ,  76   d  can be captured with the endoscope  24 . Then, the operator performs a given surgical procedure on the portion to be treated, with the end effectors. In a surgical example shown in  FIG. 20 , a tissue  121  within the body cavity  27  is gripped with the gripper  78 , while a membranous tissue  140  near the tissue  121  is cut out with the scissors  79 . 
         [0140]    With the medical robot system according to the third embodiment, the distal-end working units  76 ,  76   d  having the end effectors can be moved closer to each other by operation of the intermediate joint  60   d  and the first and second intermediate joints  58 ,  60 . Thus, in the third embodiment, a surgical procedure can be performed suitably by single port access, as in the second embodiment. 
         [0141]    Also, with the third embodiment, the manipulator  10   c  serving as a retractor performs an operation (e.g., gripping) on an affected region with the end effector provided at the distal end thereof, while the manipulator  10   c  pushes aside the organ  142  (obstacle to the operative field) with the rod-shaped member  44  having a plurality of intermediate joints. In this manner, one manipulator  10   c  doubles as a forceps and a retractor. As a result, a surgical procedure can be performed using a smaller number of manipulators. Also, the trocar for a retractor can be omitted, and thus a much less-invasive surgery can be achieved. 
         [0142]    Although certain preferred embodiments of the present invention have been shown and described in detail, it should be understood that various changes and modifications may be made therein without departing from the scope of the appended claims.