Patent Publication Number: US-2022225861-A1

Title: Camera head adaptor

Description:
TECHNICAL FIELD 
     The present invention relates to a camera head adaptor for holding an endoscope. 
     BACKGROUND ART 
     As a robot for holding an endoscope, for example, surgical assistance systems described in Patent Documents 1 and 2 have been proposed. Such a surgical assistance system is composed of a base unit and a robot mechanism, and the robot mechanism has a support column, a first robot arm that is attached to the tip of the support column so as to be rotatable, a second robot arm that is attached to the tip of the first robot arm so as to be rotatable, and a device support that is attached to the tip of the second robot arm. The device support is configured to accommodate an endoscope or other medical tool or device. 
     PRIOR ART DOCUMENTS 
     Patent Documents 
     
         
         [Patent Document 1] JP2016-93493A 
         [Patent Document 2] EP2246006A 
       
    
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     In the surgical assistance systems described in Patent Documents 1 and 2, however, when an endoscope having a structure in which an insertion portion extends from a camera head is held, the insertion portion is clamped by the device support (see FIG. 1 of Patent Document 2), and therefore the electrical wirings and optical cables in the insertion portion are liable to be stressed. This stress may damage the electrical wirings, optical cables, etc. in the insertion portion, thus leading to the instability of the treatment tool&#39;s operation and the image capture, and there are concerns about problems such as deterioration in the image quality of captured images. 
     Moreover, the insertion portion is clamped by adjusting the distance between two clamping materials provided at the tip of the device support. This distance adjustment is performed while balancing the weight of the camera head and the insertion portion, and the operation is therefore somewhat complicated. 
     Accordingly, an object of the present invention is to provide a camera head adaptor that allows an endoscope to be detachably attached with a simple operation and that can prevent stress on electrical wirings, optical cables, etc. in an insertion portion due to a camera head being held. Another object of the present invention is to provide a camera head adaptor that can readily respond to the change in the size or shape of a camera head by adopting a simple configuration comprising a holding portion that holds the camera head and a connecting portion and a coupling portion that are provided at both ends of the holding portion. 
     Means for Solving the Problems 
     To achieve the above objects, the present invention provides a camera head adaptor for holding an endoscope having a camera head, comprising: a holding portion that holds the camera head of the endoscope in a detachable manner; a connecting portion that extends along an observation optical axis of the camera head and can be attached to a support structure; and a coupling portion that couples the holding portion and the connecting portion. 
     In the camera head adaptor of the present invention, the holding portion preferably has a release structure that can release holding of the camera head when an external force of a predetermined value or more is applied to the endoscope or the camera head adaptor. 
     In the camera head adaptor of the present invention, preferably, the holding portion is composed of an elastically deformable material and comprises a plurality of wall portions that elastically hold the camera head inserted in the holding portion while being in contact with the camera head, and the release structure is preferably configured such that the holding of the camera head is released by elastic deformation or plastic deformation of the plurality of wall portions when the external force of the predetermined value or more is applied to the endoscope or the camera head adaptor. 
     In the camera head adaptor of the present invention, the connecting portion preferably comprises an engaging portion that enables detachable attachment to the support structure. 
     In the camera head adaptor of the present invention, preferably, the support structure is a robot comprising a bendable arm portion and the connecting portion is detachably attached to the arm portion. 
     In the camera head adaptor of the present invention, preferably, the endoscope is configured such that an insertion portion, an electrical cable, and an optical cable extend from the camera head, the holding portion holds only the camera head of the endoscope, and the electrical cable and the optical cable extend from the coupling portion to outside. 
     In the camera head adaptor of the present invention, preferably, the camera head has a change in an outer shape when viewed along a direction in which the observation optical axis extends, and the holding portion has an inner surface shape corresponding to the outer shape of the camera head. 
     In the camera head adaptor of the present invention, preferably, the plurality of wall portions of the holding portion includes two side wall portions that extend along a direction of a central axis of the holding portion and face each other and the camera head is supported by the two side wall portions. 
     In the camera head adaptor of the present invention, the two side wall portions preferably have a facing distance that decreases in a front-side portion in the direction of the central axis toward a front and decreases in a rear-side portion toward a rear. 
     In the camera head adaptor of the present invention, preferably, the plurality of wall portions of the holding portion further includes a bottom wall portion that connects the two side wall portions to each other on a back side in an insertion direction of the camera head and the camera head is supported by the two side wall portions and the bottom wall portion. 
     In the camera head adaptor of the present invention, the front-side portion of the holding portion is preferably provided with a groove portion that allows the insertion portion extending from the camera head held by the holding portion to extend to outside without bending. 
     In the camera head adaptor of the present invention, preferably, an opening portion that allows the camera head to be inserted is formed between the two side wall portions, and when the camera head is inserted in the holding portion, an operation unit of the camera head is exposed from the opening portion. 
     In the camera head adaptor of the present invention, preferably, the coupling portion has a space that merges into a space accommodating the camera head in the holding portion and the electrical cable and the optical cable are connected to the camera head without bending. 
     Effect of the Invention 
     According to the present invention, it is possible to provide a camera head adaptor that allows the endoscope to be detachably attached with a simple operation and that can prevent stress on electrical wirings, optical cables, etc. in the insertion portion due to the camera head being held. Moreover, by adopting a simple configuration comprising the holding portion that holds the camera head and the connecting portion and coupling portion that are provided at both ends of the holding portion, it is possible to provide a camera head adaptor that can readily respond to the change in the size or shape of the camera head. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1( a )  is a perspective view illustrating a state in which an endoscope and a holder are attached to a camera head adaptor according to one or more embodiments of the present invention, and  FIG. 1( b )  is a perspective view illustrating a state in which the endoscope and the holder are detached. 
         FIG. 2  is a perspective view illustrating a state in which the holder and the arm portion of a robot are separated from each other. 
         FIG. 3( a )  is a plan view of the camera head adaptor as viewed from above,  FIG. 3( b )  is a bottom view of the camera head adaptor as viewed from below, and  FIG. 3( c )  is a perspective view of the camera head adaptor as viewed from the bottom side. 
         FIG. 4( a )  is a perspective view illustrating a state in which the camera head adaptor, the holder, and an attachment member of the arm portion are joined to each other and  FIG. 4( b )  is a perspective view illustrating a state in which the camera head adaptor, the holder, and the attachment member of the arm portion are separated from each other. 
         FIG. 5( a )  is a perspective view of the holder as viewed from the rear upper side and  FIG. 5( b )  is a perspective view of the holder as viewed from the front lower side. 
         FIG. 6( a )  is a plan view of the holder as viewed from above,  FIG. 6( b )  is a rear view of the holder as viewed from the rear side, and  FIG. 6( c )  is a front view of the holder as viewed from the front side. 
         FIG. 7  is a diagram in which a cross-sectional view of the holder as viewed along the C-C′ line of  FIG. 6  and a diagram virtually illustrating a right-side wall portion of the connecting portion of the camera head adaptor to be inserted into the holder are combined and illustrated. 
         FIG. 8( a )  is a diagram illustrating a state in which the connecting portion is displaced downward from the state of  FIG. 7  and inserted in the holder and  FIG. 8( b )  is a diagram illustrating a state in which the connecting portion is displaced frontward from the state of  FIG. 8( a ) . 
     
    
    
     EMBODIMENTS FOR CARRYING OUT THE INVENTION 
     Hereinafter, the camera head adaptor according to one or more embodiments of the present invention will be described in detail with reference to the drawings. 
     In the following description, an observation optical axis AX 1  of an endoscope  100  and a central axis AX 2  along the longitudinal direction of a camera head adaptor  20  will be set, the front-rear direction along the central axis AX 2  will be referred to as a D 11 -D 12  direction, and the up-down direction and the right-left direction (width direction) which are orthogonal to the front-rear direction and orthogonal to each other will be referred to as a D 21 -D 22  direction and D 31 -D 32  direction, respectively. The central axis AX 2  coincides approximately with the observation optical axis AX 1  when the endoscope  100  is attached to the camera head adaptor  20 . In each figure, D 11 , D 12 , D 21 , D 22 , D 31 , and D 32  may be referred to as a front side, a rear side, an upper side, a lower side, a left side, and a right side, respectively. 
     In the present embodiment, an example of holding the endoscope  100  used for endoscopic surgery will be described for a form in which a holder  60  can be attached to a robot for surgical assistance as a support structure. Examples of the support structure of the present embodiment include a robot whose arm portion can be bent, for example, by pneumatic drive, but the camera head adaptor  20  of the present embodiment can also be applied to a robot of a different operating principle, a robot whose arm portion is not bent for drive, and a structure other than a robot. 
     As illustrated in  FIG. 1( a ) , the camera head adaptor  20  holds the endoscope  100  in a detachable manner. The camera head adaptor  20  is detachably attached to an attachment member  11  of the arm portion of the robot via the holder  60 . 
     As illustrated in  FIG. 2 , the arm portion of the robot includes a tip holding unit  10  and a gimbal mechanism unit  14 . The holder  60  is attached to the tip of the tip holding unit  10 . As illustrated in  FIG. 2 , the tip holding unit  10  is attached to the gimbal mechanism unit  14  and has an approximately circular shape in a plan view as viewed along the central axis AX 2  of the camera head adaptor  20 . 
     The tip holding unit  10  holds the holder  60  in a detachable manner via the attachment member  11  provided at the tip portion and thereby holds the camera head adaptor  20  attached to the holder  60 . The attachment member  11  is disposed concentrically with the tip holding unit  10  in a plan view along the central axis AX 2  and has a circular shape having a smaller diameter than that of the tip holding unit  10 . 
     The gimbal mechanism unit  14  supports the camera head adaptor  20  so that the camera head adaptor  20  is rotatable around the central axis AX 2  along the observation optical axis AX 1  of the endoscope  100  and also rotatable around a direction intersecting the central axis AX 2 , preferably a direction extending orthogonally to the central axis AX 2 . 
     &lt;Endoscope&gt; 
     As illustrated in  FIG. 1( b ) , the endoscope  100  includes a camera head  110 , an insertion portion  120 , an electrical cable  131 , and an optical cable  132  and has an operation unit  111  on the upper surface. 
     The camera head  110  includes an imaging element (not illustrated) for capturing the image of an object to be observed/imaged and an optical system (not illustrated) for forming an image on the imaging element and has the observation optical axis AX 1  corresponding to the optical axis of the imaging element. The camera head  110  has a change in the outer shape when viewed along the direction in which the observation optical axis AX 1  extends. Specifically, the camera head  110  has a diameter that decreases in a front-side portion (D 11  side portion) in the observation optical axis AX 1  toward the front and decreases in a rear-side portion (D 12  side portion) in the observation optical axis AX 1  toward the rear, and the intermediate portion between them is in a cylindrical shape having approximately the same diameter. 
     The housing of the camera head  110  is composed of a rigid material in order to protect the built-in imaging element and optical system and to reliably maintain the arrangement relationship between them. On the other hand, the tubular material constituting the outer circumference of the insertion portion  120  is composed of a flexible material that can be bent and deformed when inserted into the patient&#39;s body. In addition, the tubular materials constituting the outer circumferences of the electrical cable  131  and the optical cable  132  are composed of flexible materials that allow the deformation in accordance with the routing arrangement. The housing of the camera head  110 , the tubular material of the insertion portion  120 , the tubular material of the electrical cable  131 , and the tubular material of the optical cable  132  are composed, for example, of resin materials as the materials having the above-described properties. 
     The user can operate the operation unit  111  thereby to perform the start/completion of the imaging, the adjustment of the imaging conditions by operating the built-in optical system, the adjustment of the illumination intensity, etc. 
     The insertion portion  120  is provided on one end portion side of the camera head  110  in the direction along the observation optical axis AX 1 , and the electrical cable  131  and the optical cable  132  are provided on the other side in the direction along the observation optical axis AX 1 . Thus, the insertion portion  120 , the camera head  110 , the electrical cable  131 , and the optical cable  132  are arranged in this order from the object side along the observation optical axis AX 1 . 
     The electrical cable  131  and the optical cable  132  are smaller in size than the camera head  110  in the width direction (D 31 -D 32  direction) and are arranged side by side in the up-down direction (D 21 -D 22  direction). 
     The insertion portion  120  is provided so as to extend along the observation optical axis AX 1  and has, in its inside, an optical fiber or the like that guides the light emitted from an external light source to the tip surface and a path that guides the light incident from the tip surface to the camera head  110 . The insertion portion  120  may be provided therein with a treatment tool for treating an object, such as forceps or a path for ejecting water or air, a wire for bending and deforming the insertion portion  120 , etc. 
     The electrical cable  131  is configured such that a supply line for supplying the electric power to the camera head  110  and a transmission line for transmitting the imaging data from the imaging element to an external image processing unit or display unit are inserted in the electrical cable  131 . The optical cable  132  has a path such as an optical fiber for guiding the emitted light from the external light source to the insertion portion  120  side. 
     &lt;Camera Head Adaptor&gt; 
     As illustrated in  FIG. 1( b ) , the camera head adaptor  20  is formed so as to extend along the direction of the central axis AX 2  parallel to the observation optical axis AX 1  of the endoscope  100  and includes a holding portion  30  located on the front side, a connecting portion  40  located on the rear side, and a coupling portion  50  that couples the holding portion  30  and the connecting portion  40  to each other. 
     The holding portion  30  holds the camera head  110 , which has a rigid housing, of the endoscope  100  in a detachable manner. As illustrated in  FIGS. 3( a ), 3( b ), and 3( c ) , the holding portion  30  extends along the direction of the central axis AX 2  and includes two side wall portions  31  and  32  facing each other across the central axis AX 2  and a bottom wall portion  33  that connects the two side wall portions  31  and  32  to each other on the back side in the insertion direction of the camera head  110  into the holding portion  30 . The two side wall portions  31  and  32  have a facing distance that decreases in the front-side (D 11  side) portion in the direction along the central axis AX 2  toward the front and decreases in the rear-side (D 12  side) portion toward the rear so as to correspond to the shape of the housing of the camera head  110 , and the intermediate portion between them has approximately the same facing distance. Thus, the holding portion  30  has an inner surface shape corresponding to the outer shape of the camera head  110 . 
     Front tip portions  31   a  and  32   a  of the two side wall portions  31  and  32  are connected to each other, and a groove portion  30   a  along the central axis AX 2  is provided between the front tip portions  31   a  and  32   a . The upper side of the groove portion  30   a  is open. That is, the groove portion  30   a  is formed in the front-side portion of the holding portion  30 . When the camera head  110  is disposed in the holding portion  30  of the camera head adaptor  20 , the insertion portion  120  extends to the outside through the groove portion  30   a ; therefore, the insertion portion  120  can be extended without bending, and the camera head  110  can be held while suppressing the stress applied to the insertion portion  120 . Moreover, the insertion portion  120  is supported by being in contact with the groove portion  30   a.    
     As substitute for the groove portion  30   a , a hole portion may be provided so as to pass through the connection portion between the front tip portions  31   a  and  32   a  of the two side wall portions  31  and  32  along the direction of the central axis AX 2 . 
     The camera head adaptor  20  is manufactured, for example, by integral molding of a resin. In the camera head adaptor  20 , the two side wall portions  31  and  32  have an opening portion  30   b  with which the camera head  110  can be inserted in a space  30   s  between the side wall portions  31  and  32  (see  FIG. 3( a ) ). The opening portion  30   b  is positioned and sized so that the operation unit  111  is exposed when the camera head  110  is inserted and arranged in the above space  30   s.    
     The camera head adaptor  20  has flexibility so as to be capable of reliably holding the camera head  110  in the above space in a normal surgical operation and allowing the camera head  110  to be inserted into the above space  30   s  by elastic deformation of the two side wall portions  31  and  32 . In the holding portion  30 , the camera head  110  inserted in the space  30   s  between the two side wall portions  31  and  32  is supported by the two side wall portions  31  and  32  at the two sides of the camera head  110  facing each other and also supported by the bottom wall portion  33  at the bottom portion of the camera head  110 . When the two side wall portions  31  and  32  have shapes in which the curvature, bend, or thickness is adjusted so that the upper end portions (ridge portions on the upper side (D 21  side)) of the two side wall portions  31  and  32  are closer to each other than the lower end portions are, and the two side wall portions  31  and  32  are in contact with or close to a part of the upper surface of the camera head  110  accommodated therein, this is preferred because the camera head  110  can be reliably held. 
     The side wall portions may be composed of a plurality of three or more wall portions, provided that the camera head  110  can be reliably held. 
     By configuring the holding portion  30  in this way, the camera head  110  can be reliably held in the space  30   s , and the holding portion  30  serves as a release structure that is configured such that the holding of the camera head  110  can be released by elastic deformation or plastic deformation of the two wall portions  31  and  32  when an external force of a predetermined value or more is applied to the endoscope  100  or the camera head adaptor  20 . The above predetermined value is preliminarily set as a value sufficiently large with respect to the external force applied during the operation in a normal surgical operation or setting operation, and the camera head  110  can be released from the camera head adaptor  20  when an external force of the predetermined value or more is applied. The shapes and flexibility (elasticity) of the two side wall portions  31  and  32  of the camera head adaptor  20  are set so that such a release structure functions. 
     The coupling portion  50  is composed of portions in which the two side wall portions  31  and  32  extend from the holding portion  30 , and the space between the two side wall portions  31  and  32  merges into the space  30   s  in the holding portion  30 . The facing distance between the two side wall portions  31  and  32  in the width direction (D 31 -D 32  direction) is set smaller than that of the holding portion  30 . This facing distance is smaller than the camera head  110  and is large enough to allow the thickest portions of the electrical cable  131  and the optical cable  132  to be inserted. The coupling portion  50  is not provided with a bottom portion and has a shape passing through in the up-down direction. The camera head  110  cannot be inserted into the coupling portion  50  due to such a shape, and therefore the user can easily insert the camera head  110  into the holding portion  30 , which is the correct insertion position, simply by adjusting the camera head  110  back and forth. Moreover, it is possible to prevent disconnection and other problems because the connection portion in which the electrical cable  131  and the optical cable  132  are connected to the camera head  110  is inserted in the coupling portion  50  without bending, so that the connection portions between the camera head  110  and the electrical cable  131  and optical cable  132  are less likely to be stressed during the operation of the endoscope or robot. 
     The coupling portion  50  is not limited to the above structure, provided that it can reliably couple the holding portion  30  and the connecting portion  40 . For example, another configuration is also possible in which the two side wall portions  31  and  32  are not extended to the coupling portion  50 , but are joined to each other on the near side of the coupling portion  50  to form a closed shape and a rod-shaped coupling portion or a plate-shaped coupling portion, for example, is joined to the holding portion having such a shape. 
     In the present embodiment, the two side wall portions  31  and  32  are flexible (elastic), but can be composed of a rigid material, provided that the camera head  110  can be inserted and reliably held. In this case, it is preferred to give the coupling portion  50  flexibility or elasticity because the insertability of the camera head  110  can be ensured. 
     As illustrated in  FIGS. 3( a ) to 3( c ) , the connecting portion  40  is in a plate shape extending rearward from the rear end of the coupling portion  50  and has two side surfaces  41  and  42  facing each other. 
     As illustrated in  FIGS. 3( a ) to 3( c )  or  FIG. 4( b ) , the left side surface  41  of the connecting portion  40  is provided with three engaging protrusions  41   a ,  41   b , and  41   c  protruding leftward as engaging portions. The two engaging protrusions  41   a  and  41   b  on the upper side are provided at the same positions in the up-down direction (D 21 -D 22  direction), and the two engaging protrusions  41   a  and  41   c  on the front side are provided at the same positions in the front-rear direction (D 11 -D 12  direction). The three engaging protrusions  41   a ,  41   b , and  41   c  have the same shape as each other. 
     As illustrated in  FIGS. 3( a ) to 3( c )  or  FIG. 7 , the right side surface  42  is provided with three engaging protrusions  42   a ,  42   b , and  42   c  protruding rightward as engaging portions. As illustrated in  FIG. 7 , the two engaging protrusions  42   a  and  42   b  on the upper side are provided at the same positions in the up-down direction, and the center positions are arranged at a distance L 1  in the front-rear direction. The two engaging protrusions  42   a  and  42   c  on the front side are provided at the same positions in the front-rear direction, and the center positions are arranged at a distance L 2  in the up-down direction. The distance between the center position of the engaging protrusion  42   b  on the rear side and a rear end surface  40   a  of the connecting portion  40  is set to a distance L 3 . The three engaging protrusions  42   a ,  42   b , and  42   c  have the same shape as each other and also have the same shapes as those of the three engaging protrusions  41   a ,  41   b , and  41   c  on the left side surface  41 . 
     These three engaging protrusions  42   a ,  42   b , and  42   c  are arranged at positions corresponding to those of the three engaging protrusions  41   a ,  41   b , and  41   c  on the left side surface  41  with respect to the surface extending in the up-down direction and including the central axis AX 2 . 
     &lt;Holder&gt; 
     As illustrated in  FIGS. 5( a ) and 5( b )  and  FIGS. 6( a ) to 6( c ) , the holder  60  includes a base material portion  61  that is provided at the rear portion and two side wall portions  70  and  80  and a bottom wall portion  90  that are provided on a front surface  61   a  of the base material portion  61 . The base material portion  61 , the two side wall portions  70  and  80 , and the bottom wall portion  90  are manufactured, for example, by integral molding of a rigid resin material. 
     The base material portion  61  has a planar shape that spreads approximately like a circular disk when viewed along the front-rear direction (D 11 -D 12  direction), and the rear portion of the base material portion  61  is provided with an attaching portion  62  that protrudes rearward and is joined to the arm portion of a robot in a detachable manner. 
     The holder  60  may be configured to be fixed to the arm portion of a robot, or the attachment member of the arm portion may have the same configuration as the holder  60 . 
     The attaching portion  62  is provided within a diameter range smaller than the diameter of the planar shape of the base material portion  61  and has a predetermined width W (see  FIG. 6( b ) ) in the right-left direction (D 31 -D 32  direction) and a shape extending along the up-down direction (D 21 -D 22  direction). In the attaching portion  62 , overhanging portions  63   a  and  64   a  extending outward in the right-left direction are provided on the upper portions of two side surfaces  63  and  64  facing each other in the right-left direction, respectively. In the state illustrated in  FIG. 6( b ) , the attaching portion  62  has a predetermined height H from a bottom portion  62   a  to the overhanging portions  63   a  and  64   a.    
     The two side wall portions  70  and  80  of the holder  60  are provided so as to extend from the front surface  61   a  of the base material portion  61  to the front side (D 11  side) and face each other in the right-left direction (D 31 -D 32  direction). The bottom wall portion  90  extends from the front surface  61   a  of the base material portion  61  to the front side and is connected to the lower portions of the two side wall portions  70  and  80 . This allows a space  60   a  to be formed in front of the base material portion  61 . The space  60   a  is surrounded by the two side wall portions  70  and  80  and the bottom wall portion  90 , and the upper side of the space  60   a  is open. The camera head adopter holding portion is thus configured, which holds the camera head adaptor  20  in a detachable manner. 
     As illustrated in  FIG. 6( a ) , the upper inner surface of the left-side first side wall portion  70  is provided with two insertion recessed portions  71  and  72  that are recessed toward the outside (left side (D 31  side)). These insertion recessed portions  71  and  72  are provided side by side so that the center positions are arranged at a predetermined distance L 1  in the front-rear direction. 
     The upper inner surface of the right-side second side wall portion  80  of the holder  60  is provided with two insertion recessed portions  81  and  82  that are recessed toward the outside (right side (D 32  side)) so as to face the two insertion recessed portions  71  and  72  of the left-side first side wall portion  70 , respectively. These insertion recessed portions  81  and  82  are provided side by side so that the center positions are arranged at a predetermined distance L 1  in the front-rear direction. In the rear-side insertion recessed portion  82 , its center position is separated from the front surface  61   a  of the base material portion  61  by a distance L 3  in the front-rear direction. 
     As illustrated in  FIG. 7 , the front-side insertion recessed portion  81  of the right-side second side wall portion  80  is provided in a linked manner with a first fixing recessed portion  83  extending frontward at a position at which a predetermined distance is extended downward, and the rear-side insertion recessed portion  82  is provided in a linked manner with a second fixing recessed portion  84  extending frontward at a position at which the same distance as that of the front-side insertion recessed portion  81  is extended downward. The second fixing recessed portion  84  is provided in a linked manner with the insertion recessed portion  81  in the front-rear direction and is provided at the same height position as the first fixing recessed portion  83  in the up-down direction. 
     The front-side insertion recessed portion  81  extends further downward from the linked portion with the first fixing recessed portion  83  and is provided in a linked manner with a third fixing recessed portion  85  extending frontward at a position at which a distance L 2  is extended. Here, the three fixing recessed portions  83 ,  84 , and  85  are arranged so that the relative positional relationships of the three fixing recessed portions  83 ,  84 , and  85  in the up-down and front-rear directions correspond to the relative positional relationships of the three engaging protrusions  42   a ,  42   b , and  42   c  of the connecting portion  40  in the up-down and front-rear directions. The three fixing recessed portions  83 ,  84 , and  85  have inner surface shapes corresponding to the outer shapes of the three engaging protrusions  42   a ,  42   b , and  42   c , respectively. When the three engaging protrusions  42   a ,  42   b , and  42   c  are inserted, therefore, they are press-fitted by applying a predetermined force, and after the press-fitting, they are fixed to such an extent that they are not detached even if an external force due to an operation such as a normal surgical operation is applied. 
     Here, although not illustrated, the insertion recessed portions  71  and  72  of the left-side first side wall portion  70  are also provided in a linked manner with a first fixing recessed portion, a second fixing recessed portion, and a third fixing recessed portion as in the insertion recessed portions  81  and  82  of the right-side second side wall portion  80 . 
     The joint between the camera head adaptor  20  and the holder  60  will be described by focusing on the joint between the right side surface  42  of the connecting portion  40  and the right-side second side wall portion  80  of the holder  60 . The left side surface  41  of the connecting portion  40  and the left-side first side wall portion  70  of the holder  60  are also joined in the same manner. 
     First, as illustrated in  FIG. 7 , the camera head adaptor  20  is located above the holder  60 , and the lower portion of the rear end surface  40   a  of the connecting portion  40  is brought into contact with the upper portion of the front surface  61   a  of the base material portion  61 . This allows the engaging protrusions  42   c  and  42   b  of the connecting portion  40  to be located above the insertion recessed portions  81  and  82 , respectively. At this time, although not illustrated, the engaging protrusions  41   c  and  41   b  of the connecting portion  40  are located above the insertion recessed portions  71  and  72  of the holder  60 , respectively. 
     Then, the camera head adaptor  20  is displaced downward or the holder  60  is displaced upward, and the engaging protrusions  42   c  and  42   b  of the connecting portion  40  are thereby inserted into the insertion recessed portions  81  and  82 , respectively ( FIG. 8( a ) ). At this time, the engaging protrusions  41   c  and  41   b  of the connecting portion  40  are also inserted into the insertion recessed portions  71  and  72 , respectively. 
     Subsequently, taking the right side surface  42  as an example, as illustrated in  FIG. 8( a ) , the engaging protrusion  42   c  is brought into contact with a bottom portion  81   a  of the insertion recessed portion  81  while the engaging protrusion  42   b  is brought into contact with a bottom portion  82   a  of the insertion recessed portion  82 , and the insertion into the second side wall portion  80  is thereby restricted in the up-down direction. Then, by moving the camera head adaptor  20  frontward or the holder  60  rearward from the state of  FIG. 8( a ) , the engaging protrusion  42   a  is press-fitted into the first fixing recessed portion  83 , the engaging protrusion  42   b  is press-fitted into the second fixing recessed portion  84 , and the engaging protrusion  42   c  is press-fitted into the third fixing recessed portion  85  ( FIG. 8( b ) ). Through this operation, the connecting portion  40  and the holder  60  are joined, and the camera head adaptor  20  and the holder  60  are fixed to each other. 
     Here, as illustrated in  FIG. 7 , in the three fixing recessed portions  83 ,  84 , and  85 , it is preferred to provide respective recessed portions or through holes that are recessed in the second side wall portion  80  along the right-left direction (D 31 -D 32  direction), and dispose, in the recessed portions or through holes, elastic members  83   a ,  84   a , and  85   a  that can be elastically extended toward the inside of the holder  60  along the right-left direction. Through this configuration, when the engaging protrusions  42   a ,  42   b , and  42   c  are press-fitted into the three fixing recessed portions  83 ,  84 , and  85 , respectively, elastic forces can be applied along the right-left direction, and the camera head adaptor  20  and the holder  60  can therefore be more firmly fixed to each other. 
     When the camera head adaptor  20  is moved rearward or the holder  60  is moved frontward from the state in which the camera head adaptor  20  and the holder  60  are fixed to each other as above, the engaging protrusion  42   a , the engaging protrusion  42   b , and the engaging protrusion  42   c  are extracted from the first fixing recessed portion  83 , the second fixing recessed portion  84 , and the third fixing recessed portion  85 , respectively. Then, by pulling up the connecting portion  40  upward to pull out the engaging protrusion  42   a , the engaging protrusion  42   b , and the engaging protrusion  42   c  from the insertion recessed portions  81  and  82 , it is possible to release the camera head adaptor  20  from the holder  60 . Thus, the above steps allow the holder  60  to hold the camera head adaptor  20  in a detachable manner. 
     The attaching portion  62  of the holder  60  has a shape corresponding to a holding groove portion  12  provided in the attachment member  11  of the tip holding unit  10  of the robot&#39;s arm portion. Specifically, as illustrated in  FIG. 2 , the holding groove portion  12  is a rectangular groove having a width W and a height H in a plan view, and one end in the direction of the height H is an opening portion  13 . The holder  60  can therefore be joined to the tip holding unit  10  in a detachable manner by press-fitting the attaching portion  62  from the opening portion  13  of the holding groove portion  12 . 
     Here, an outer peripheral surface  61   b  of the base material portion  61  of the holder  60  or an outer peripheral surface  62   b  of the attaching portion  62  may be used, for example, as a drape holding portion. When the tip portion of a drape is attached to any or each of the outer peripheral surfaces  61   b  and  62   b  and the drape is made to cover the arm portion or further the robot as a whole, the robot can be reliably kept in a clean state, and the holder  60  and the camera head adaptor  20  contaminated by the surgical operation or the like can be easily separated from the robot. 
     While the present invention has been described with reference to the above embodiment, the present invention is not limited to the above embodiment and can be improved or modified within the scope of the purpose of improvement or the idea of the present invention. 
     INDUSTRIAL APPLICABILITY 
     As described above, the camera head adaptor according to the present invention is useful in that it allows an endoscope to be detachably attached with a simple operation and it can prevent stress on electrical wirings, optical cables, etc. in the insertion portion due to the camera head being held. 
     DESCRIPTION OF REFERENCE NUMERALS 
     
         
           10  Tip holding unit 
           11  Attachment member 
           12  Holding groove portion 
           13  Opening portion 
           14  Gimbal mechanism unit 
           20  Camera head adaptor 
           30  Holding portion 
           30   a  Groove portion 
           30   b  Opening portion 
           30   s  Space 
           31 ,  32  Side wall portion 
           31   a ,  32   a  Front tip portion 
           33  Bottom wall portion 
           40  Connecting portion 
           40   a  Rear end surface 
           41  Left side surface 
           41   a ,  41   b ,  41   c  Engaging protrusion 
           42  Right side surface 
           42   a ,  42   b ,  42   c  Engaging protrusion 
           50  Coupling portion 
           60  Holder 
           60   a  Space 
           61  Base material portion 
           61   a  Front surface 
           61   b  Outer peripheral surface 
           62  Attaching portion 
           62   a  Bottom portion 
           62   b  Outer peripheral surface 
           63 ,  64  Side surface 
           63   a ,  64   a  Overhanging portion 
           70  First side wall portion 
           71 ,  72  Insertion recessed portion 
           80  Second side wall portion 
           81 ,  82  Insertion recessed portion 
           81   a ,  82   a  Bottom portion 
           83 ,  84 ,  85  Fixing recessed portion 
           83   a ,  84   a ,  85   a  Elastic member 
           90  Bottom wall portion 
           100  Endoscope 
           110  Camera head 
           111  Operation unit 
           120  Insertion portion 
           131  Electrical cable 
           132  Optical cable 
         AX 1  Observation optical axis 
         AX 2  Central axis 
         H Height 
         L 1 , L 2 , L 3  Distance 
         W Width