Abstract:
The present invention provides an endoscope comprising: an insertion unit which is to be inserted into a body; and a pipeline provided inside the insertion unit for supplying a fluid to a balloon mounted on an outer peripheral surface of the insertion unit, wherein the pipeline has a plurality of openings in an axial direction of the insertion unit on the outer peripheral surface of the insertion unit. Therefore, the endoscope of the present invention can easily fix a balloon and keep airtightness after the fixation, and can raise a degree of freedom of a mounting location of the balloon.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to an endoscope, and in particular, to an endoscope having an insertion unit that is inserted into deep digestive tracts such as a small intestine and a large intestine to be observed. 
         [0003]    2. Description of the Related Art 
         [0004]    When an insertion unit of an endoscope is inserted in deep digestive tracts, such as a small intestine, since a force is not easily transmitted to a tip of the insertion unit by merely pushing the insertion unit because of complicated bending of an intestinal tract, it is hard to perform insertion into the depth. For example, when excessive bending or flexion arises in the insertion unit, it becomes impossible to further insert the insertion unit into the depth. Then, a method is proposed, which prevents excessive bending or flexion of an insertion unit by putting an insertion aid on the insertion unit of the endoscope and inserting the insertion unit into a body cavity, and guiding the insertion unit by this insertion aid. 
         [0005]    Japanese Patent Application Laid-Open No. 2005-334475 discloses an endoscope apparatus which not only provides a first balloon in a tip portion of an insertion unit of an endoscope, but also provides a second balloon in a tip portion of an insertion aid (this is also called an over tube or a sliding tube). It is possible to make the insertion unit and insertion aid fix in an intestinal tract, such as a small intestine, by having the first balloon and second balloon expanded. Hence, by inserting the insertion unit and insertion aid by turns with repeating expansion and shrinkage of the first balloon and second balloon, it is possible to insert the insertion unit into the depth of a complicatedly bending intestinal tract, such as a small intestine. 
       SUMMARY OF THE INVENTION 
       [0006]    By the way, in recent years, there has been a request of modifying a mounting location of a balloon, which is mounted on an insertion unit of an endoscope, according to an application. For example, when performing a bending operation of a bend of an insertion unit after expanding the balloon, it is desired to mount the balloon in a base end side further than in the bend. In addition, when it is desired to enlarge a stroke of the insertion operation mentioned above, or when it is desired to obtain a blurless observation image after expansion of a balloon, it is desired to mount the balloon near a tip of an insertion unit. 
         [0007]    Nevertheless, in the endoscope disclosed in Japanese Patent Application Laid-Open No. 2005-334475, since an opening of an air supply passage to supply and suck air to/from the balloon on an outer peripheral surface of a tip portion of the insertion unit, it is only possible to mount the balloon in the vicinity of this opening. 
         [0008]    A method in which a tube is post-installed, the tube being an air supply passage in an outside of an insertion unit is conceivable as a method of mounting a balloon in an arbitrary location. However, in this case, since a tip of the tube must be arranged inside the balloon, there arise problems of becoming difficult to fix the balloon, and being hard to keep airtightness after fixing the balloon. 
         [0009]    The present invention was made in view of such a situation, and aims at providing an endoscope which can easily fix a balloon and keep airtightness after the fixation, and can raise a degree of freedom of a mounting location of the balloon. 
         [0010]    In order to attain the above-mentioned object, an invention according to a first aspect is an endoscope apparatus which includes an insertion unit which is inserted into a body, and a pipeline which is provided inside the insertion unit, and supplies a fluid to a balloon which is mounted on an outer peripheral surface of the insertion unit, characterized in that the pipeline is made to have openings in a plurality of locations in an axial direction of the insertion unit on the outer peripheral surface of the insertion unit. 
         [0011]    According to the invention described in the first aspect, since the pipeline is made to have openings in a plurality of locations in an axial direction of the insertion unit, it is possible to select an opening from the plurality of openings and to mount a balloon. That is, according to the invention described in the first aspect, it is possible to select a mounting position of a balloon in the axial direction of the insertion unit from two or more locations. In addition, according to the invention of the first aspect, since the pipeline is provided inside the insertion unit, it is possible to easily mount a balloon, and to keep securely airtightness between an outer peripheral surface of the insertion unit and an inner peripheral surface of the balloon. 
         [0012]    An invention according to a second aspect is characterized in that each sealing device is mounted detachably in the plurality of openings in the invention according to the first aspect. As the each sealing device according to the second aspect, for example, there is a rubber ring which is fit outside on the insertion unit, a rubber plug pressed fit into the opening, a plug member fit to or screwed into the opening, an end of the balloon fixed in a location of the opening, or a valve member arranged in the pipeline. 
         [0013]    An invention described in a third aspect is characterized in that at least one opening among the plurality of openings is provided in a fixed location of a balloon which is mounted so as to be made to communicate with another opening, in the invention according to the first or second aspects. According to the invention according to the third aspect, it is possible to seal the opening by a balloon which is mounted on another opening. 
         [0014]    An invention according to a fourth aspect is characterized in that the opening is provided in a concave groove formed in an outer periphery of the insertion unit over a round, in the invention according to any one of the first to third aspects. According to the invention according to the fourth aspect, since the opening is provided in the concave groove, it is possible to arrange a rubber ring, which seals the opening, inside the concave groove, and hence, it is possible to prevent the rubber ring from projecting from an outer peripheral surface of the insertion unit. In addition, according to the invention according to the fourth aspect, since the opening is provided in the concave groove, it becomes hard for the opening to be sealed by the balloon when a fluid is sucked from the opening, and hence, it is possible to shrink the balloon securely. 
         [0015]    An invention according to a fifth aspect is characterized in that the plurality of openings is provided in a tip side and a base end side of a bend respectively, which is formed in the insertion unit and is given a bending operation, in the invention according to any one of the first to fourth aspects. 
         [0016]    According to the present invention, since a plurality of openings is provided in an axial direction of the insertion unit, it is possible to mount a balloon in two or more locations in the axial direction of the insertion unit. In addition, according to the present invention, since a pipeline is provided inside an insertion unit, it is possible to easily mount a balloon, and to keep securely airtightness between an outer peripheral surface of the insertion unit and an inner peripheral surface of the balloon. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  is a system block diagram of an endoscope apparatus to which an endoscope which relates to the present invention is applied; 
           [0018]      FIG. 2  is a perspective view showing a tip portion of an insertion unit; 
           [0019]      FIG. 3  is a pipeline diagram showing a pipeline in the insertion unit schematically; 
           [0020]      FIG. 4  is a pipeline diagram of the insertion unit where an opening in a tip side is selected and a balloon is mounted; 
           [0021]      FIG. 5  is a pipeline diagram of the insertion unit where an opening in a base end side is selected and a balloon is mounted; 
           [0022]      FIG. 6  is a pipeline diagram of the insertion unit where two opening are provided in a connection ring; 
           [0023]      FIG. 7  is a pipeline diagram of the insertion unit where a mounting location of a balloon is different from that in  FIG. 6 ; and 
           [0024]      FIG. 8  is a pipeline diagram of the insertion unit where a mounting location of a balloon is different from that in  FIG. 6 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0025]    Preferable embodiments of an endoscope according to the present invention will be described in detail with reference to accompanying drawings. 
         [0026]      FIG. 1  is a system block diagram showing an example of an endoscope apparatus to which the endoscope which relates to the present invention is applied. As shown in  FIG. 1 , an endoscope apparatus mainly includes an endoscope  10  and a balloon controller  100 . 
         [0027]    The endoscope  10  includes a hand operation unit  14  and an insertion unit  12  which is installed in connection with this hand operation unit  14  and is inserted inside a living body. A universal cable  16  is connected to the hand operation unit  14 , and an LG connector  18  is provided at a tip of this universal cable  16 . The LG connector  18  is detachably connected to a light source apparatus  20 , and thereby illumination light is transmitted to an illumination light optical system (not shown) provided at a tip of the insertion unit  12 . In addition, an electric connector  24  is connected to the LG connector  18  through a cable  22 , and this electric connector  24  is detachably connected to a processor  26 . 
         [0028]    In the hand operation unit  14 , an air supply/water supply button  28 , a suction button  30 , a shutter release  32 , and a function switching button  34  are juxtaposed, while a pair of angle knobs  36  and  36  are provided. A balloon air supply opening  38  is formed by an L-shaped bent pipe in a base end portion of the hand operation unit  14 . A below-mentioned balloon  60  can be expanded or shrunk by supplying or sucking a fluid, such as air, to/from this balloon air supply opening  38 . 
         [0029]    The insertion unit  12  includes an elastic portion  40 , a bending portion  42 , and a tip portion  44  sequentially from a hand operation unit  14  side. The elastic portion  40  is a portion which has sufficient flexibility, and is installed in connection with a base end side of the bending portion  42 . 
         [0030]    The bending portion  42  is constructed so as to be bent remotely by rotating the angle knobs  36  and  36  of the hand operation unit  14 . For example, the bending portion  42  is constructed so that the bending portion  42  may be given a bending operation by a plurality of cylindrical joint rings being coupled rotatably by a guide pin, a plurality of operation wires being made to be inserted inside the joint rings and being guided by the guide pin, and the operation wires being pushed and pulled. It is possible to orient the tip portion  44  in a desired direction by giving the bending operation to this bending portion  42 . 
         [0031]    The tip portion  44  is a hard portion provided at a tip of the insertion unit  12 , and as shown in  FIG. 2 , an observation optical system  52 , illumination light optical systems  54  and  54 , an air supply/water supply nozzle  56 , and a forceps opening  58  are provided in its tip surface  45 . A CCD (not shown) is arranged behind the observation optical system  52 , and a signal cable (not shown) is connected to a substrate which supports that CCD. The signal cable is inserted into the insertion unit  12 , the hand operation unit  14 , a universal cable  16 , and the like, and is extended to an electric connector  24  to be connected to a processor  26 . Therefore, an observation image taken in by the observation optical system  52  is imaged on a light-receiving surface of the CCD to be converted into an electric signal, and this electric signal is output to the processor  26  in  FIG. 1  through the signal cable to be converted into a video signal. Thereby, the observation image is displayed on a monitor  50  connected to the processor  26 . 
         [0032]    An emission end of a light guide (not shown) is arranged behind the illumination light optical systems  54  and  54  in  FIG. 2 , the light guide is inserted into the insertion unit  12 , hand operation unit  14 , and universal cable  16  in  FIG. 1 , and its incident end is arranged inside the LG connector  18 . Hence, by connecting the LG connector  18  to the light source apparatus  20 , illumination light radiated from the light source apparatus  20  is transmitted to the illumination light optical systems  54  and  54  in  FIG. 2  through the light guide, and is radiated forward from the illumination light optical systems  54  and  54 . 
         [0033]    The air supply/water supply nozzle  56  communicates with a valve (not shown) operated with the air supply/water supply button  28  in  FIG. 1 , and this valve communicates with an air supply/water supply connector  48  provided in the LG connector  18 . An air supply/water supply device not shown is connected to the air supply/water supply connector  48 , and air and water are supplied. Hence, it is possible to inject air or water from the air supply/water supply nozzle  56  to the observation optical system by operating the air supply/water supply button  28 . 
         [0034]    The forceps opening  58  in  FIG. 2  communicates with a forceps insertion portion  46  in  FIG. 1 . Therefore, it is possible to draw a treatment tool from the forceps opening  58  by inserting the treatment tool, such as a forceps, from the forceps insertion portion  46 . In addition, the forceps opening  58  communicates with a valve operated with the suction button  30 , and this valve is connected to a suction connector  49  of the LG connector  18 . Hence, it is possible to suck a pathological change portion or the like from the forceps opening  58  by connecting a not-shown suction device to the suction connector  49 , and manipulating the valve with the suction button  30 . 
         [0035]      FIG. 3  is a diagram showing a pipeline in the insertion unit  12  schematically. As shown in this diagram, a pipeline  66  is provided inside the insertion unit  12 , this pipeline  66  is branched on the way, and two openings are provided in an outer peripheral surface of the insertion unit  12 . That is, two openings  64  and  65  are provided in the outer peripheral surface of the insertion unit  12 . 
         [0036]    The opening  64  is provided in a concave groove  67  formed in a base end portion of the tip portion  44 . The concave groove  67  is formed in an outer peripheral surface of the tip portion  44  over a round, and is formed in width of a rubber ring  69  shown in FIG.  5 . Hence, when the rubber ring  69  is fit outside the concave groove  67 , the rubber ring  69  is housed inside the concave groove  67 . 
         [0037]    The opening  65  is provided in a concave groove  68  formed in a base end portion of a connection ring  41  which connects the bending portion  42  and/with the elastic portion  40 . The concave groove  68  is formed in an outer peripheral surface of the connection ring  41  over a round, and is formed in the same width as the above-mentioned concave groove  67 , that is, in the width of the rubber ring  69  shown in  FIG. 4 . Hence, when the rubber ring  69  is fit outside the concave groove  68 , the rubber ring  69  is contained inside the concave groove  68 . 
         [0038]    The rubber ring  69  is formed in a ring shape of an elasticity material such as rubber, and its inner diameter before outside fitting is formed a little smaller than outer diameters in locations of the concave grooves  67  and  68 . Hence, by making the rubber ring  69  fit outside the concave groove  67  or  68 , the rubber ring  69  sticks to a peripheral surface of the concave groove  67  or  68  by its own elastic force, and the opening  64  or  65  is sealed. In addition, although it is made to make the common rubber ring  69  fit outside the concave grooves  67  and  68  in this embodiment, it is not limited to this, but different rubber rings may be made to fit outside. 
         [0039]    As shown in  FIG. 4  or  5 , the balloon  60  is mounted in a location of the opening  64  or  65 . The balloon  60  is formed of an elastic material, such as rubber, in substantially cylindrical shape whose end portion is shrunk, and includes a tip portion  60 A and a base end portion  60 B with a smaller diameter, and a swelling portion  60 C which is a central portion. After inserting the insertion unit  12  and arranging it in a predetermined location of the insertion unit  12 , this balloon  60  is fixed to the insertion unit  12  by putting rings  61  and  62  (referring to  FIG. 2 ), made of rubber, in the tip portion  60 A and base end portion  60 B. In addition, a fixing method of the tip portion  60 A and base end portion  60 B is not limited particularly, it is also sufficient to wind a string to fix them. In addition, the balloon  60  is constructed expandably, and it is made to be substantially spherical when it expands, and it sticks to an outer surface of the insertion unit  12  when it shrinks. 
         [0040]    The above-mentioned pipeline  66  in  FIG. 3  includes a tube, a pipe, a hole, and the like, and a base end side (left side in  FIG. 3 ) of the pipeline  66  communicates with the balloon air supply opening  38  of the hand operation unit  14  in  FIG. 1 . The below-mentioned balloon controller  100  is connected to the balloon air supply opening  38  through a tube  110 . Therefore, it is possible to supply and suck a fluid to/from the openings  64  and  65  by supplying and sucking a fluid, such as air, from the balloon controller  100 . 
         [0041]    The balloon controller  100  is an apparatus which not only supplies and sucks a fluid to the balloon  60  (refer to  FIGS. 4 and 5 ) to expand and shrink the balloon  60 , but also controls internal pressure of the balloon  60  at that time, and is mainly constructed by an apparatus main body  102  and a hand switch  104  for remote control. 
         [0042]    A power switch SW 1 , a stop switch SW 2 , and a pressure display unit  106  are provided in a front face of the apparatus main body  102 . The pressure display unit  106  is a panel which displays a pressure value of the balloon  60 , and displays an error code at the time of occurrence of an abnormality such as a burst of a balloon. 
         [0043]    The tube  110  which performs air supply and suction to/from the balloon  60  is connected to the front face of the apparatus main body  102 . A backflow preventing unit  112  for preventing a backflow of humors when the balloon  60  is burst is provided in a junction between the tube  110  and apparatus main body  102 . The backflow preventing unit  112  is constructed by incorporating a filter for gas-liquid separation into an inside of a hollow disk-like case (not shown) which is mounted detachably in the apparatus main body  102 , and prevents a liquid with the filter from flowing into the apparatus main body  102 . 
         [0044]    On the other hand, various kinds of switches are provided in the hand switch  104 . For example, a stop switch which is the same as the stop switch SW 2  of the apparatus main body  102  side, an ON/OFF switch which indicates pressurization or depressurization of the balloon  60 , a pause switch for holding pressure of the balloon  60 , and the like are provided. This hand switch  104  is electrically connected to the apparatus main body  102  through a cord  130 . In addition, although not shown in  FIG. 1 , a display unit which shows an air supply state or an exhaust state of the balloon  60  is provided in the hand switch  104 . 
         [0045]    The balloon controller  100  constructed as described above not only supplies air to the balloon  60  to expand it, but also to control the air pressure to a constant value to keep the balloon  60  in an expanding state. In addition, the balloon controller  100  not only sucks air from the balloon  60  to shrink it, but also to control the air pressure to a steady value to keep the balloon  60  in a shrinking state. 
         [0046]    The balloon controller  100  is connected to a balloon-dedicated monitor  82 , and makes a pressure value, and expansion and shrinkage states of the balloon  60  displayed on the balloon-dedicated monitor  82  when expanding and shrinking the balloon  60 . In addition, the pressure value, and expansion and shrinkage states of the balloon  60  may be superimposed on an observation image of the endoscope  10  to be displayed on the monitor  50 . 
         [0047]    As an example of an operation method of the endoscope apparatus constructed as described above, the insertion unit  12  is inserted in a push mode, and a balloon  60  is expanded if necessary, and is fixed inside a living body (for example, large intestine). Then, after drawing the insertion unit  12  to simplify a pipe shape of the living body (for example, large intestine), the balloon  60  is shrunk and the insertion unit  12  is further inserted in the depth of an intestinal tract. For example, the insertion unit  12  is inserted from an anus of a subject, the insertion unit  12  is fixed to the intestinal tract by the balloon  60  being expanded when the tip of the insertion unit  12  passes over a sigmoid colon, and the insertion unit  12  is pulled for the sigmoid colon to be made substantially linear. Then, the balloon  60  is shrunk and the tip of the insertion unit  12  is being inserted in the depth of the intestinal tract. Thereby, it is possible to insert the insertion unit  12  into the depth of the intestinal tract. 
         [0048]    Next, an operation of the endoscope  10  constructed as described above will be explained. 
         [0049]    The endoscope  10  includes two openings  64  and  65  in the insertion unit  12 , and a surgeon selects one of the two openings  64  and  65  to mount the balloon  60  according to an application.  FIGS. 2 and 4  show examples of the balloon  60  being mounted in location of the opening  64 , and  FIG. 5  shows an example of the balloon  60  being mounted in a location of the opening  65 . 
         [0050]    As shown in  FIGS. 2 and 4 , when the balloon  60  is mounted in the location of the opening  64 , the tip portion  60 A of the balloon  60  is fixed on an outer peripheral surface of the tip portion  44  which is nearer to the tip than the opening  64 , and the base end portion  60 B of the balloon  60  is fixed on an outer peripheral surface of the bending portion  42 . Thereby, since the opening  64  is arranged inside the swelling portion  60 C of the balloon  60 , it is possible to expand and shrink the balloon  60  by supplying and sucking a fluid, such as air, to/from the opening  64 . 
         [0051]    In this case, the rubber ring  69  is made to fit outside the concave groove  68 , and the opening  65  which is not selected is sealed with the rubber ring  69 . Thereby, when a fluid is supplied and sucked by the balloon controller  100 , the fluid is supplied and sucked to/from the opening  64 . 
         [0052]    When the balloon  60  is mounted in the location of the opening  64  as described above, the balloon  60  is mounted near the tip of the insertion unit  12 . Hence, since the observation optical system  52  of the tip portion  44  is fixed to the inside of the living body when the balloon  60  is expanded and the insertion unit  12  is fixed to the inside of the living body (large intestine or the like), it is possible to obtain an observation image with a small blur. In addition, since the balloon  60  is near the tip of the insertion unit  12 , the insertion unit  12  can be fixed to the further depth of the living body when the balloon  60  is expanded and fixed to the inside of the living body. Hence, it is possible to enlarge a stroke in one insertion operation. 
         [0053]    As shown in  FIG. 5 , when mounting the balloon  60  in a location of the opening  65 , the tip portion  60 A of the balloon  60  is fixed on an outer peripheral surface of the connection ring  41  which is nearer to the tip than the opening  65 , and the base end portion  60 B of the balloon  60  is fixed on an outer peripheral surface of the elastic portion  40 . Thereby, since the opening  65  is arranged inside the swelling portion  60 C of the balloon  60 , it is possible to expand and shrink the balloon  60  by supplying and sucking a fluid, such as air, to/from the opening  65 . 
         [0054]    In this case, the rubber ring  69  is made to fit outside the concave groove  67 , and the opening  65  which is not selected is sealed with the rubber ring  69 . Thereby, when the fluid is supplied and sucked by the balloon controller  100 , the fluid is supplied and sucked to and from the opening  65 . 
         [0055]    When the balloon  60  is mounted in the location of the opening  65  as described above, the balloon  60  is mounted in a base end side further than the bending portion  42 . Hence, it is possible to perform a bending operation of the bending portion  42  freely in a state that the balloon  60  is expanded and the insertion unit  12  is fixed to the inside of the living body (large intestine or the like). Therefore, since it is possible to orient the tip portion  44  to a pathological change portion or the like in a state that the insertion unit  12  is fixed to the inside of the living body, this is suitable for making an endoscope treatment tool, such as a forceps, inserted into a forceps channel of the endoscope  10  to treat the pathological change portion or the like. 
         [0056]    In this way, according to this embodiment, it is possible to select a mounting position of the balloon  60  according to an application of a balloon type endoscope. In addition, in the above-mentioned endoscope  10 , since the pipeline  66  is provided in the insertion unit  12 , differently from a case that the pipeline  66  is arranged outside the insertion unit  12 , it is possible to mount the balloon  60  easily, and to secure airtightness between the balloon  60  and insertion unit  12 . 
         [0057]    In addition, in the endoscope  10  of this embodiment, since the openings  64  and  65  are provided in the concave grooves  67  and  68 , when the rubber ring  69  is made to fit outside and seal the opening  64  or  65 , it is possible to prevent the rubber ring  69  from projecting from an outer peripheral surface of the insertion unit  12 . Furthermore, in this embodiment, since the openings  64  and  65  are provided in the concave grooves  67  and  68 , it becomes hard for the opening  64  or  65  to be sealed by the balloon  60  when a fluid is sucked from the opening  64  or  65 , and hence, it is possible to shrink the balloon  60  securely. 
         [0058]    Furthermore, although the rubber ring  69  is used in the embodiment mentioned above as a sealing device which seals the opening  64  or  65  which is not selected, the sealing device is not limit to this, and may be just a device which seals the opening  64  or  65 , or a branching portion of the pipeline  66 . For example, it is also sufficient to press fit a rubber plug into the opening  64  or  65 , or to seal the opening  64  or  65  by fitting or screwing a plug member into the opening  64  or  65 . In addition, as mentioned later, it is also sufficient to seal the opening  64  or  65  using the tip portion  60 A or base end portion  60 B of the balloon  60 . Furthermore, a pipeline-sealing device such as a solenoid valve may be provided in the branching portion of the pipeline  66 . 
         [0059]    In addition, although the example of providing the two openings  64  and  65  is explained in the embodiment mentioned above, the number of the openings is not limited to this, but three or more openings may be provided in an axial direction of the insertion unit  12 . For example, an opening may be provided in an outer peripheral surface of the elastic portion  40  in addition to the openings  64  and  65  mentioned above. 
         [0060]    Furthermore, although the opening  64  is provided in the tip portion  44  of the insertion unit  12  and the opening  65  is provided in the connection ring  41  in the embodiment mentioned above, locations of the openings are not limited to this, but what is necessary is just to be formed in different locations in the axial direction of the insertion unit  12 . For example, as shown in  FIGS. 6 and 7 , openings  70  and  71  may be provided in the tip portion and base end portion of the connection ring  41 , respectively. The openings  70  and  71  are provided in concave grooves  72  and  73  formed in the outer peripheral surface of the connection ring  41  over a round in a circumferential direction, respectively. Widths of the concave grooves  72  and  73  are formed in widths of the tip portion  60 A and base end portion  60 B of the balloon  60 , respectively. 
         [0061]    When the opening  70  is selected in the endoscope constructed as described above, as shown in  FIG. 6 , the tip portion  60 A of the balloon  60  is fixed on the bending portion  42 , and the base end portion  60 B of the balloon  60  is fixed in a location of the concave groove  73 . Hence, the opening  71  which is not selected is sealed by the base end portion  60 B of the balloon  60 . 
         [0062]    In addition, when the opening  71  is selected, as shown in  FIG. 7 , the tip portion  60 A of the balloon  60  is fixed by the concave groove  72 , and the base end portion  60 B of the balloon  60  is fixed by the elastic portion  40 . Hence, the opening  70  which is not selected is sealed by the tip portion  60 A of the balloon  60 . 
         [0063]    According to the endoscope constructed as described above, it is possible to select a mounting position of the balloon  60  from a tip portion side and a base end side of the connection ring  41 . In addition, according to this embodiment, since the opening  70  or  71  which is not selected is sealed using the tip portion  60 A or base end portion  60 B of the balloon  60 , it is not necessary to provide a sealing device separately. In addition, according to this embodiment, since the tip portion  60 A or base end portion  60 B of the balloon  60  after mounting are arranged inside the concave groove  72  or  73  by providing the openings  70  and  71  in the concave grooves  72  and  73 , it is possible to prevent the tip portion  60 A or base end portion  60 B from projecting from an outer peripheral surface of the insertion unit  12 . 
         [0064]    Moreover, in the case of the above-mentioned endoscope, the balloon  60  may be mounted as shown in  FIG. 8 . That is, the tip portion  60 A of the balloon  60  may be fixed in the tip side further than the concave groove  72 , and the base end portion  60 B may be fixed in the base end side further than the concave groove  73 . Thereby, the two openings  70  and  71  are arranged inside the balloon  60 , and supply and suction of a fluid are performed through the two openings  70  and  71 . Hence, it is possible to prevent the balloon from expanding and shrinking with partially uneven. 
         [0065]    In addition, although the pipeline  66  is branched and is made to communicate with the openings  64  and  65 , or  70  and  71  in the embodiment mentioned above, the present invention is not limited to this, but an independent pipeline for each of the openings  64 ,  65 ,  70  and  71  may be provided, and may be connected to the balloon controller  100 .