Patent Publication Number: US-2013253271-A1

Title: Endoscope

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage application under 35 U.S.C. §371 of International Application No. PCT/KR2011/008298, filed on Nov. 2, 2011, which claims priority to Korean Application No. 10-2010-0117368, filed Nov. 24, 2010, the disclosure of each is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     Embodiments of the present invention relates to an endoscope having a rotating device to axially rotate a bending member. 
     BACKGROUND ART 
     Generally, a medical endoscope is a medical instrument which is inserted into a body cavity or an internal organ to allow an operator to view the interior of the internal organ without a surgical operation and has made considerable contributions to medicine. 
     Unlike other medical imaging instruments such as radiography systems, an endoscope is directly inserted into the human body. Thus, endoscopic inspection advantageously allows an operator to directly observe the shape or condition of an internal organ or a cavity of the human body with the naked eye. 
     Such an endoscope includes a bending member which is bendable to move a view member at a front end of the endoscope within the human body, and an operating unit which an operator grips to operate the bending member. 
     The bending member has two degrees of freedom (2-DOF) so as to bend in a vertical direction and a horizontal direction. Bending in the vertical direction and bending in the horizontal direction are performed independently of each other. As such, an operator moves the view member at the front end of the endoscope to a target position by bending the bending member in the vertical direction or the horizontal direction while gripping the operating unit. 
     However, although bending in the vertical direction and bending in the horizontal direction are performed independently of each other, if bending motions in the two directions are coupled with each other, an actual bending output differs from a bending value input by an operator using the operating unit. This may problematically necessitate several bending operations to move the view member at the front end of the endoscope to a target position. 
     DISCLOSURE 
     Technical Problem 
     It is an aspect of the present invention to provide an endoscope having a rotating device to axially rotate a bending member. 
     Technical Solution 
     In accordance with one aspect of the present invention, an endoscope includes a flexible member which is freely bendable upon receiving external force, a bending member provided at a front end of the flexible member, the bending member being bendable with one degree of freedom, a rotating device rotatably coupled to the flexible member in an axial direction of the flexible member and serving to rotate the bending member in the axial direction, and an operating unit connected to the rotating device and having a rotation operation unit to rotate the rotating device. 
     The bending member may include a plurality of bending segments jointed to one another and elastic members placed between the respective bending segments to return the plurality of bending segments to original positions thereof. 
     At least a part of the flexible member may undergo torsion when axial torque is applied to the flexible member, and the bending member may be secured to the front end of the flexible member and is rotatable along with the flexible member. 
     The rotating device may include a torsional device coupled to the flexible member so as to apply the axial torque to the flexible member, and the flexible member may include a first flexible portion secured to the operating unit, a second flexible portion connected to a front end of the first flexible portion so as to undergo torsion when the torque is applied thereto, and a third flexible portion connected to a front end of the second flexible portion so as to be rotated in the axial direction. 
     The torsional device may include a coupling member secured to the operating unit and the first flexible portion so as to secure the first flexible portion to the operating unit, and a rotating member rotatably coupled to the coupling member while being secured to the third flexible portion. 
     The coupling member may include a rotation guide boss formed on a circumference thereof, and the rotating member may include a rotation guide recess into which the rotation guide boss is inserted. 
     The rotating member may include a rotating body secured to the third flexible portion to extend toward the first flexible portion, and a rotating disc secured to the rotating body and adapted to receive the torque from the rotation operation unit. 
     The torsional device may further include a friction member placed between the coupling member and the rotating member to increase friction. 
     The rotation operation unit may include a rotation wire connected to the rotating device, the rotating device may include a rotating tube assembly formed by axially connecting at least two tubes to each other, and a front end of the rotating tube assembly may be axially rotatable relative to a rear end of the rotating tube assembly. 
     The rotating tube assembly may include a stationary tube secured to the flexible member and a rotating tube rotatably inserted into the stationary tube while being secured to the bending member. 
     The stationary tube may include a rotation guide slit perforated in a circumference thereof, the rotating tube may include a rotation pin movably inserted into the rotation guide slit, and the rotating tube may be rotatable relative to the stationary tube as the rotation pin is moved along the rotation guide slit. 
     The rotating tube may further include a rotation wire connector to which the rotation wire is secured. 
     The rotation wire connector may be secured to the rotation pin. 
     The stationary tube may further include a rotation wire hanger to guide the rotation wire to the rotation wire connector. 
     The rotating tube assembly may further include a sliding tube coupled to the stationary tube so as to reciprocate in an axial direction of the stationary tube. 
     The stationary tube may include a reciprocation guide pin to guide reciprocation of the sliding tube, and the sliding tube may include a reciprocation guide slot into which the reciprocation guide pin is inserted. 
     The sliding tube may include a rotation leading slit perforated in a curved circumferential wall thereof to extend obliquely relative to a center axis of the sliding tube, the rotating tube may include a rotation pin inserted into the rotation leading slit, and the rotating tube may be rotated during reciprocation of the sliding tube as the rotation pin is moved along the rotation leading slit. 
     The stationary tube may further include a rotation guide groove to guide rotation of the rotating tube, and the rotating tube may further include a rotation protrusion circumferentially formed and inserted into the rotation guide groove. 
     In accordance with another aspect of the present invention, an endoscope includes
         a flexible member that is bendable in an arbitrary direction, a bending member connected to a front end of the flexible member, the bending member being bendable with one degree of freedom, an operating unit for an operator to grip placed behind the flexible member, and a rotating device coupled to the flexible member so as to be rotated in an axial direction of the flexible member and serving to rotate the bending member in the axial direction, wherein the operating unit includes a housing defining an external appearance of the operating unit, a bending operation unit mounted to the housing and connected to the bending member to enable bending of the bending member, and a rotation operation unit mounted to the housing and connected to the rotating device, and wherein the bending operation unit includes a bending wire connected to the bending member.       

     A rear end of the flexible member may be secured to an inner position of the housing, the rotating device may include a torsional device coupled to the flexible member to surround at least a part of the flexible member so as to transmit axial torque to the flexible member, and the torsional device may be placed within the housing. 
     The bending operation unit may further include a bending operation pulley placed within the housing to operate the bending wire, the rotation operation unit may include a rotation wire connected to the rotating device and a rotation operation pulley placed within the housing to operate the rotation wire, and the bending operation pulley and the rotation operation pulley may have the same axis of rotation. 
     The bending operation unit may further include a bending operation knob rotatably mounted to the housing to operate the bending wire, the rotation operation unit may include a rotation wire connected to the rotating device and a rotation operation knob rotatably mounted to the housing to operate the rotation wire, and an axis of rotation of the bending operation unit and an axis of rotation of the rotation operation knob may be perpendicular to each other. 
     The rotation operation unit may include a rotation wire connected to the rotating device, and the bending wire and the rotation wire may be arranged close to each other within the flexible member. 
     In accordance with another aspect of the present invention, an endoscope includes
         a flexible member that is bendable in an arbitrary direction, a bending member connected to a front end of the flexible member, the bending member being bendable with one degree of freedom, a torsional device coupled to the flexible member to transmit axial torque to the flexible member, and an operating unit including a rotation operation unit connected to the torsional device, wherein the flexible member includes a first flexible portion secured to the operating unit, a second flexible portion connected to a front end of the first flexible portion so as to undergo torsion when the torque is applied thereto, and a third flexible portion connected to a front end of the second flexible portion so as to be rotated in the axial direction, and wherein the torsional device includes a coupling member secured to the operating unit and the first flexible portion so as to secure the first flexible portion to the operating unit, and a rotating member rotatably coupled to the coupling member while being secured to the third flexible portion.       

     Advantageous Effects 
     With provision of a bending member having one degree of freedom and performing axial rotation, motion of the bending member may correspond to manipulation of an operator. Thus, the bending member is bent and axially rotated according to operator manipulation, which allows the operator to more easily move a view member of an endoscope to a target position. 
     In addition, easy movement of the view member of the endoscope may reduce time required for endoscopic inspection, which may reduce physical burden applied to a person being diagnosed. 
    
    
     
       DESCRIPTION OF DRAWINGS 
       These and/or other aspects of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is a view illustrating an endoscope system according to an embodiment of the present invention; 
         FIG. 2  is a view illustrating an insert unit of an endoscope according to an embodiment of the present invention; 
         FIGS. 3 and 4  are views illustrating a bending member of the endoscope according to one embodiment of the present invention; 
         FIG. 5  is a perspective view illustrating a rotating device according to an embodiment of the present invention; 
         FIG. 6  is a cross sectional view illustrating a configuration of the rotating device; 
         FIG. 7  is a view illustrating an operation of the rotating device; 
         FIG. 8  is a perspective view illustrating a rotating device according to another embodiment of the present invention; 
         FIG. 9  is an exploded perspective view illustrating major components of the rotating device; 
         FIGS. 10 to 12  are views illustrating an operation of the rotating device; 
         FIG. 13  is a perspective view illustrating a configuration of a rotating device according to a further embodiment of the present invention; 
         FIG. 14  is an exploded perspective view illustrating major components of the rotating device; 
         FIGS. 15 to 17  are views illustrating an operation of the rotating device; and 
         FIGS. 18 and 19  are views illustrating arrangement of a rotation wire according to an embodiment of the present invention. 
     
    
    
     BEST MODE 
     Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.  FIG. 1  is a view illustrating an endoscope system according to an embodiment of the present invention,  FIG. 2  is a view illustrating an insert unit of an endoscope according to an embodiment of the present invention, and  FIGS. 3 and 4  are views illustrating a bending member of the endoscope according to one embodiment of the present invention. 
     As illustrated in  FIGS. 1 and 2 , an endoscope system  1  for use in endoscopic inspection includes an endoscope  10 , a light source device  20 , a signal processing device  30 , and a display device  35 . The endoscope  10  includes an insert unit  40  to be inserted into an internal organ or a body cavity, and an operating unit  50  that an operator grips to perform a variety of functions of the endoscope  10 . 
     The insert unit  40  includes a freely bendable flexible member  60 , a bending member  70 , and a hard tip member  80  connected to a front end of the bending member  70 . The flexible member  60  is connected to the operating unit  50 . The flexible member  60  may consist of a helical steel band  63 , a metallic wire mesh  62  surrounding the helical steel band  63 , and a covering tube  61 . The wire mesh  62  may be made of stainless steel. The entire flexible member  60  has sufficient flexibility to be passively bent upon receiving external force. 
     The tip member  80  may be provided with an objective lens  81  to focus on an object and a light guide lens  82  to guide light directed from the light source device  20  to the object. A charge coupled device (not shown) may be provided behind the objective lens  81  to convert an image of the object collected by the objective lens  81  into an image signal. The charge coupled device may be connected to the objective lens  81 . 
     A signal cable  83  is connected to the charge coupled device (not shown) and is inserted through the insert unit  40  and the operating unit  50 . The signal cable  83  is also connected to the signal processing device  30  by way of the interior of a universal cable  90  that extends rearward from the operating unit  50 . 
     A light guide  84  is inserted through the insert unit  40  and the operating unit  50  to guide light from the light source device  20  to the object. The light guide  84  is connected to the light source device  20  by way of the interior of the universal cable  90 . The light source device  20  irradiates light into the human body through the light guide  84 . 
     The signal processing device  30  receives an image photographed by the tip member  80  of the endoscope  10  through the signal cable  83  and processes the image signal. The display device  35  receives the image signal from the signal processing device  30  and displays it to the operator of the endoscopy system. 
     The bending member  70  is connected to a front end of the flexible member  60 . The bending member  70  takes the form of a tube consisting of a plurality of ring-shaped bending segments  71  connected to one another while defining a space therein. The plurality of bending segments  71  is centrally jointed to one another such that the bending member  70  is bendable with one degree of freedom. The respective bending segments  71  may be provided at a coupling portion thereof with a connector, such as a rivet or the like. The bending member  70  is bendable within a single plane. 
     A bending wire  52  is inserted through the bending member  70 . More particularly, a pair of bending wires  52  is provided. These bending wires  52  may be arranged to face each other within the interior space of the bending member  70 . One end of each bending wire  52  is secured to a front end of the bending member  70  and the other end of the bending wire  52  sequentially passes through the bending member  70  and the flexible member  60  to thereby be connected to the operating unit  50 . The operating unit  50  is provided with a bending operation unit  51  connected to the bending wires  52 . As the operator pulls any one of the pair of bending wires  52  by operating the bending operation unit  51 , the bending member  70  is bendable within a single plane. 
     As illustrated in  FIGS. 3 and 4 , the bending member  70  includes the plurality of bending segments  71  and a plurality of elastic members  73 . The single bending wire  52  is inserted through the bending member  70  and the elastic member  73  is arranged at an opposite side of the bending wire  52 . Each bending segment  71  includes a first joint  74  and a second joint  75  shaped to correspond to each other, whereby the plurality of bending segment  71  is coupled to one another without separate connecting members. 
     The elastic members  73  are placed between the respective bending segments  71 . One end of the single bending wire  52  is connected to the front end of the bending member  70  and the other end of the bending wire  52  is connected to the bending operation unit  51 . If the operator applies tension to the bending wire  52  by operating the bending operation unit  51 , elastic energy is accumulated in the elastic member  73  simultaneously with bending of the bending member  70 . Then, if the operator releases the tension applied to the bending wire  52 , the bending segments  71  are returned to original positions thereof by the elastic energy of the elastic member  73 . 
     As the bending member  70  is bendable within a single plane, a viewing range of the endoscope  10  is limited to the plane in which the bending member  70  is bendable. Accordingly, the endoscope  10  includes a rotating device  100 , which axially rotates the bending member  70  so as to move a view member of the endoscope  10  to various positions within the human body. 
       FIG. 5  is a perspective view illustrating the rotating device according to an embodiment of the present invention,  FIG. 6  is a cross sectional view illustrating a configuration of the rotating device, and  FIG. 7  is a view illustrating an operation of the rotating device. 
     As illustrated in  FIGS. 5 to 7 , the rotating device includes a torsional device  100  coupled to the flexible member  60 . The torsional device  100  is coupled to the flexible member  60  so as to surround the flexible member  60 , thereby applying axial torque to the flexible member  60 . 
     The flexible member  60  includes a first flexible portion  64  secured to the operating unit  50 , a second flexible portion  65  connected to a front end of the first flexible portion  64 , the second flexible portion  65  performing torsional motion, and a third flexible portion  66  connected to a front end of the second flexible portion  65  so as to be axially rotated. 
     To allow the torsional device  100  to perform torsional motion upon receiving torque, the second flexible portion  65  may have lower torsional rigidity than the first flexible portion  64  and the third torsional portion  66 . To this end, the second flexible portion  65  may be made of a helical metallic band or wire mesh having a small torsional rigidity, or may not contain the aforementioned metallic structures. 
     The torsional device  100  includes a coupling member  110  secured to the operating unit  50  and the first flexible portion  64 , a rotating member  120  secured to the third flexible portion  66  while being axially rotatably coupled to the coupling member  110 , and a friction member  150  placed between the coupling member  110  and the rotating member  120 . 
     The coupling member  110  has a hollow cylindrical shape such that the first flexible portion  64  is inserted through the coupling member  110 . The first flexible portion  64  comes into close contact with an inner surface of the coupling member  110  and is secured to the coupling member  110 . The first flexible portion  64  may be interference-fitted to the coupling member  110 . 
     The rotating member  120  has a hollow cylindrical shape such that the coupling member  110  and the second flexible portion  65  are inserted through the rotating member  120 . A rear end of the third flexible portion  66  is secured to the rotating member  120 . A rear end of the rotating member  120  is axially rotatably coupled to the coupling member  110  and the flexible member  60 . The coupling member  110  is circumferentially provided at an outer surface thereof with rotation guide bosses  112 , and the rotating member  120  is provided at an inner surface thereof with rotation guide recesses  121  corresponding to the rotation guide bosses  112 . The rotating member  120  is slidable and rotatable relative to the coupling member  110  in a state in which the rotating guide bosses  121  are inserted in the rotation guide recesses  112 . 
     The rotating member  120  includes a hollow cylindrical rotating body  130  secured to a rear end of the third flexible portion  66  so as to be rotated along with the third flexible portion  66 , and a rotating disc  140  secured to a rear end of the rotating body  130  so as to receive an external force. To secure the rear end of the third flexible portion  66  to the rotating body  130 , a contact member  131  is placed on a front end of the rotating body  130 . The rotating disc  140  has a circular disc shape and may be provided throughout an outer periphery thereof with rotating teeth  141 . The rotating body  130  and the rotating disc  140  may be separately provided so as to be coupled with each other, or may be integrally formed with each other. 
     If the operator applies axial torque to the rotating member  120 , the second flexible portion  65  exhibits torsional motion and the third flexible portion  66  is axially rotated along with the rotating member  120 . When torque applied to the rotating member  120  is released, the second flexible portion  65  may be returned to an original state thereof by torsional elastic energy accumulated in the second flexible portion  65 . Thus, to prevent the second flexible portion  65  from being returned to an original state before torsional deformation when the torque applied to the rotating member  120  is released, the friction member  150  is placed between the coupling member  110  and the rotating member  120  to increase friction between the coupling member  110  and the rotating member  120 . The friction member  150  includes an elastic member  151  to come into contact with the coupling member  110  and the rotating member  120  with elastic energy accumulated therein. One end of the elastic member  151  is secured to the coupling member  110  and the other end of the elastic member  151  is positioned to apply elastic force to the rotating member  120 . 
     Hereinafter, operation of the torsional device  100  will be described. As illustrated in  FIG. 7 , the operating unit  50  includes a housing  500  defining an external appearance of the operating unit  50 , and the bending operation unit  51  and a rotation operation unit  55  mounted to the housing  500 . 
     The bending operation unit  51  includes a bending operation knob  54  placed at an outer surface of the housing  500  and the bending wire  52  connected to the bending operation knob  54 . A power transmission member, such as a bending operation pulley  53 , may be placed between the bending operation knob  54  and the bending wire  52 . A power source, such as an electrically driven motor, may be additionally provided between the bending operation knob  54  and the power transmission member. 
     The rotation operation unit  55  includes a rotation operation knob  59  provided at the outer surface of the housing  500 , and a power transmission member, such as a gear assembly  57 , placed in the housing  500  to transmit torque that the operator applies to the rotation operation knob  59  to the torsional device  100 . The power transmission member may include a wire and pulley, or a chain and sprocket, in addition to the gear assembly  57 . Also, a power source, such as an electrically driven motor, may be additionally provided between the rotation operation knob  59  and the gear assembly  57 . 
     One side of the gear assembly  57  is connected to the rotation operation knob  59  and the other side of the gear assembly  57  is connected to the rotating disc  140  of the torsional device  100 . The torque that the operator applies to the rotation operation knob  59  is transmitted to the rotating member  120  of the torsional device  100  via the gear assembly  57 . If the rotating member  120  of the torsional device  100  applies axial torque to the rear end of the third flexible portion  66 , the second flexible portion  65  exhibits torsional motion because movement of the first flexible portion  64  is restricted by the coupling member  120 . Thereby, the third flexible portion  66  is rotated along with the rotating member  120  of the torsional device  100  and the bending member  70  connected to the front end of the flexible member  60  as illustrated in  FIG. 2  is axially rotated along with the third flexible portion  66 . 
     If torque applied to the rotation operation knob  59  is released, torsional elastic energy accumulated in the second flexible portion  65  acts as restoration force to return the second flexible portion  65  to an original state before torsional deformation. However, since the friction member  150  secured to the coupling member  110  applies friction corresponding to the restoration force to the rotating member  120 , the second flexible portion  65  is not returned to an original state before deformation and the rotating member  120  can be continuously rotated. 
     MODE FOR INVENTION 
       FIG. 8  is a perspective view illustrating a rotating device according to another embodiment of the present invention,  FIG. 9  is an exploded perspective view illustrating major components of the rotating device, and  FIGS. 10 to 12  are views illustrating an operation of the rotating device. 
     As illustrated in  FIGS. 8 to 12 , the rotating device includes a rotating tube assembly  200  formed by axially connecting three tubes to one another. 
     Both ends of the rotating tube assembly  200  may be connected to the flexible member  60 . However, since the entire rotating tube assembly  200  is rigid, connecting both ends of the rotating tube assembly  200  to the flexible member  60  may deteriorate the ability of the flexible member  60  to bend. Therefore, the rotating tube assembly  200  may be placed between the flexible member  60  and the bending member  70 . 
     The rotating tube assembly  200  includes a stationary tube  210 , a sliding tube  220  inserted into the stationary tube  210  so as to reciprocally move in a longitudinal direction within the stationary tube  210 , and a rotating tube  230  axially rotatably coupled to the stationary tube  210 . The stationary tube  210 , the sliding tube  220  and the rotating tube  230  may be coupled to one another on the same axis. 
     A rear end of the stationary tube  210  is secured to the front end of the flexible member  60 . The stationary tube  210  is circumferentially provided at an inner wall surface thereof with a rotation guide groove  212  to guide rotation of the rotating tube  230 . The rotation guide groove  212  is formed near a front end of the stationary tube  210 . 
     The stationary tube  210  includes reciprocation guide pins  211  protruding inward from the inner wall surface of the stationary tube  210  so as to guide reciprocation of the sliding tube  220 . The stationary tube  210  further includes a rotation wire hanger  213 . The rotation wire hanger  213  will be described later. 
     The sliding tube  220  has an outer diameter corresponding to an inner diameter of the stationary tube  210  and is inserted into the stationary tube  210 . The sliding tube  220  includes reciprocation guide slots  222  longitudinally perforated in a wall thereof, into which the reciprocation guide pins  211  of the stationary tube  210  are respectively inserted. 
     Rotation wires  56  are connected to the sliding tube  220 . The sliding tube  220  includes rotation wire connectors  221  to which the rotation wires  56  are connected. The rotation wires  56  include a first rotation wire  561  to move the sliding tube  220  rearward and a second rotation wire  562  to move the sliding tube  220  forward. The rotation wire connectors  221  include a first rotation wire connector  225  connected to the first rotation wire  561  and a second rotation wire connector  226  connected to the second rotation wire  562 . 
     The first rotation wire connector  225  and the second rotation wire connector  226  are provided respectively at front and rear ends of the sliding tube  220 . Also, the first rotation wire connector  225  and the second rotation wire connector  226  are located at symmetrical positions about a center axis of the sliding tube  220 . 
     The rotation wire hanger  213  of the stationary tube  210  is located in front of the first rotation wire connector  225 . The rotation wire hanger  213  and the first rotation wire connector  225  are aligned in a straight line in a longitudinal direction of the sliding tube  220 . Thus, the first rotation wire  561  is first caught by the rotation wire hanger  213  of the stationary tube  210  and thereafter, is connected to the first rotation wire connector  225  of the sliding tube  220 . As such, if tension is applied to the first rotation wire  561 , the sliding tube  220  is moved forward of the stationary tube  210 . 
     To reduce friction between the first rotation wire  561  and the rotation wire hanger  213 , the rotation wire hanger  213  has a cylindrical shape. The rotation wire hanger  213  may include a roller (not shown) rotatably secured to the stationary tube  210 . 
     During reciprocation of the sliding tube  220 , the rotating tube  230  is axially rotated while being coupled to the sliding tube  220 . To this end, the sliding tube  220  has a rotation leading slit  223  perforated in a curved circumferential wall thereof to extend obliquely relative to a center axis of the sliding tube  220 . The rotation leading slit  223  is perforated in the sliding tube  220  to communicate the interior of the sliding tube  220  with the outside. 
     The rotating tube  230  includes a rotation protrusion  231  circumferentially arranged on an outer surface of the rotating tube  230 . The rotation protrusion  231  is inserted into the rotation guide groove  212  of the stationary tube  210 . Longitudinal movement of the rotating tube  230  is restricted by the rotation protrusion  231  inserted into the rotation guide groove  212 . 
     The rotating tube  230  includes a rotation pin  232  protruding from the outer surface of the rotating tube  230 . The rotation pin  232  is inserted into the rotation leading slit  223  of the sliding tube  220 . The rotation pin  232  is moved along the rotation leading slit  223  during reciprocation of the sliding tube  220 . 
     Hereinafter, operation of the rotating tube assembly  200  will be described. As illustrated in  FIGS. 10 to 12 , the operating unit  50  includes the housing  500  defining an external appearance of the operating unit  50 , and the bending operation unit  51  and the rotation operation unit  55  mounted to the housing  500 . 
     The bending operation unit  51  includes the bending operation knob  54  rotatably placed at the housing  500  to allow the user to grip and rotate the bending operation knob  54 , a bending operation pulley  53  connected to the bending operation knob  54 , and the bending wire  52  connected to the bending operation pulley  53 . 
     The rotation operation unit  55  includes the rotation operation knob  59  rotatably provided at the housing  500  to allow the user to grip and rotate the rotation operation knob  59 , a rotation operation pulley  58  connected to the rotation operation knob  59 , and the rotation wires  56  connected to the rotation operation pulley  58 . The bending operation pulley  53  and the rotation operation pulley  58  have the same axis of rotation. 
     The bending operation unit  51  and the rotation operation unit  55  may be operated independently of each other. Thus, the rotation operation knob  59  cannot be rotated while the operator rotates the bending operation knob  54  and on the contrary, the bending operation knob  54  cannot be not rotated while the operator rotates the rotation operation knob  59 . 
     If the operator rotates the bending operation knob  54 , tension is applied to the bending wire  52 , causing the bending member  70  to be bent. However, the bending member  70  has only one degree of freedom and therefore, cannot move the view member of the endoscope  10  to various positions within the human body using only the bending operation unit  51 . 
     If the operator rotates the rotation operation knob  59  in a given direction to apply tension to the first rotation wire  561 , the sliding tube  220  is moved forwardly within the stationary tube  210 . In this case, rotation of the sliding tube  220  is restricted relative to the stationary tube  210  because the reciprocation guide pins  211  of the stationary tube  210  are inserted into the reciprocation guide slots  222  of the sliding tube  220 . 
     When the sliding tube  220  is moved forward, the rotation pin  232  of the rotating tube  230  is moved along the rotation leading slit  223 . Forward or rearward movement of the rotating tube  230  is restricted by the rotation protrusion  231  of the rotating tube  230  inserted into the rotation guide groove  212  of the stationary tube  210 . Thus, the rotating tube  230  is rotated in a given direction relative to the stationary tube  210  and the bending member  70  connected to the front end of the rotating tube  230  is rotated along with the rotating tube  230 . 
     If the operator rotates the rotation operation knob  59  in an opposite direction, the rotating tube  230  and the bending member  70  are rotated in opposite directions by the above described operation. 
       FIG. 13  is a perspective view illustrating a configuration of a rotating device according to a further embodiment of the present invention,  FIG. 14  is an exploded perspective view illustrating major components of the rotating device, and  FIGS. 15 to 17  are views illustrating an operation of the rotating device. 
     As illustrated in  FIGS. 13 to 17 , a rotating tube assembly  300 , unlike the rotating tube assembly  200  illustrated in  FIG. 9 , is formed by axially connecting two tubes to each other. 
     The rotating tube assembly  300  includes a stationary tube  310  and a rotating tube  330  inserted into the stationary tube  310  so as to be rotated relative to the stationary tube  310 . 
     The stationary tube  310  may be connected to the front end of the flexible member  60  and the rotating tube  330  may be connected to the rear end of the bending member  70 . Thus, as the rotating tube  300  is axially rotated relative to the stationary tube  310 , the bending member  70  is rotatable in an axial direction of the rotating tube assembly  300  relative to the flexible member  60 . 
     The stationary tube  310  includes a rotation guide slit  312  perforated in a circumferential direction thereof. The rotating tube  330  includes an outwardly protruding rotation pin  331 . The rotation pin  331  is configured to be inserted into the rotation guide slit  312  of the stationary tube  310 . The rotating tube  330  is rotatable relative to the stationary tube  310  as the rotation pin  331  is moved along the rotation guide slit  312  of the stationary tube  310 . 
     The rotation wire  56  is connected to the rotating tube  330 . The rotation wire  56  includes the first rotation wire  561  to rotate the rotating tube  330  in a given direction and the second rotation wire  562  to rotate the rotating tube  330  in an opposite direction. 
     The rotating tube  330  includes rotation wire connectors  332  to which the rotation wires  56  are secured. The rotation wire connector  332  may be integrally formed with the rotation pin  331 . The first rotation wire  561  and the second rotation wire  562  are connected to the rotation wire connectors  332  respectively. 
     The stationary tube  310  is provided at an inner wall surface thereof with rotation wire hangers  311  to guide the rotation wires  56  to the rotation wire connectors  332 . The rotation wire hangers  311  include a first rotation wire hanger  313  to guide the first rotation wire  561  to the rotation wire connector  332  and a second rotation wire hanger  314  to guide the second rotation wire  562  to the rotation wire connector  332 . The second rotation wire hanger  314  is located on a circumference of the rotating tube  330  where the first rotation wire hanger  313  is also located. That is, the first rotation wire hanger  313  and the second rotation wire hanger  314  are located on a single circumference. A straight line connecting the first rotation wire hanger  313  and the second rotation wire hanger  314  to each other may pass the center of the rotating tube  330 . 
     The circumference of the rotating tube  330  where the rotation wire hangers  311  are located may be equal to or be adjacent to a circumference where the rotation guide slot  312  is perforated. The rotation wire hanger  312  may include a rotation roller (not shown) to reduce friction with the rotation wire  56 . 
     Hereinafter, operation of the rotating tube assembly  300  will be described. As illustrated in  FIGS. 15 to 17 , the operating unit  50  includes the housing  500  defining an external appearance of the operating unit  50 , and the bending operation unit  51  and the rotation operation unit  55  mounted to the housing  500 . 
     The bending operation unit  51  includes the bending operation knob  54  rotatably placed at the housing  500  to allow the user to grip and rotate the bending operation knob  54 , the bending operation pulley  53  connected to the bending operation knob  54 , and the bending wire  52  connected to the bending operation pulley  53 . 
     The rotation operation unit  55  includes the rotation operation knob  59  rotatably provided at the housing  500  to allow the user to grip and rotate the rotation operation knob  59 , the rotation operation pulley  58  connected to the rotation operation knob  59 , and the rotation wires  56  connected to the rotation operation pulley  58 . The bending operation pulley  53  and the rotation operation pulley  58  have the same axis of rotation. 
     The rotation operation knob  59  and the bending operation knob  54  may have rotating shafts that are perpendicular to each other. The gear assembly  57  is placed between the rotation operation knob  59  and the rotation operation pulley  58 . 
     If the operator rotates the rotation operation knob  59  in a given direction to apply tension to the first rotation wire  561 , the first rotation wire  561  applies force to the rotation wire connector  332  of the rotating tube  330  in the given direction. The rotation pin  331  of the rotating tube  330  is moved along the rotation guide slit  312  in the given direction, and the rotating tube  330  is rotated by a predetermined angle corresponding to a distance by which the rotation pin  331  is moved. Thus, the bending member  70  connected to the rotation tube  330  is rotated along with the rotation tube  330  in an axial direction of the rotating tube  330 . 
     If the operator rotates the rotation operation knob  59  in an opposite direction, the rotating tube  330  and the bending member  70  are rotated in opposite directions by the above described operation. 
       FIGS. 18 and 19  are views illustrating arrangement of the rotation wire according to an embodiment of the present invention. 
     As illustrated in  FIGS. 18 and 19 , a pair of rotation wire guide tubes  65  and a pair of bending wire guide tubes  64  are inserted into the flexible member  60 . The rotation wire guide tubes  65  and bending wire guide tubes  64  are secured to the inner wall surface of the flexible member  60 . 
     The rotation wires  56  and the bending wires  52  are respectively inserted into the rotation wire guide tubes  65  and the bending wire guide tubes  64 . The pair of rotation wires  56  and the pair of bending wires  52  are arranged symmetrically about the center axis of the flexible member. 
     The rotation wires  56  and the bending wires  52  may be spaced apart from one another by arbitrary distances because they are independent of each other. As illustrated in  FIGS. 18 and 19 , the rotation wires  56  and the bending wires  52  may be spaced apart from one another by a possible maximum distance. Also, as illustrated in  FIGS. 18 and 19 , the rotation wire  56  and the bending wire  52  may be arranged close to each other. 
     INDUSTRIAL APPLICABILITY 
     The present invention is applicable to a medical endoscope having a bending member for endoscopic inspection. 
     Although the embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.