Abstract:
The present invention provides an endoscope comprising: an insert portion having a bending portion for bending operation and a flexible soft portion connected to the proximal end of the bending portion; an inflatable/deflatable balloon attached on the proximal side from the bending portion; and a supplying/sucking opening provided in the outer surface of a ring that connects the bending portion to the soft portion, the supplying/sucking opening supplying and sucking fluid to and from the balloon.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to an endoscope, and particularly to an endoscope having an insert portion to be inserted into a deep digestive tract, such as small intestine and large intestine, for observation. 
         [0003]    2. Description of the Related Art 
         [0004]    When an insert portion of an endoscope is inserted into a deep digestive tract, such as small intestine, simply pushing the insert portion, in many cases, will not transfer the force to the tip of the insert portion because of complex bends of the intestinal tract, making deep insertion difficult. For example, when the insert portion is bent or flexed more than necessary, the insert portion cannot be inserted any deeper. To address this problem, there has been proposed a method for preventing the insert portion from being bent or flexed more than necessary by covering the insert portion of the endoscope with an insert assist tool, inserting the insert portion covered by the insert assist tool in a body cavity and using the insert assist tool to guide the insert portion. 
         [0005]    Japanese Patent Application Laid-Open No. 2005-230083 describes an endoscope apparatus including a first balloon provided at the tip of an insert portion of the endoscope and a second balloon provided at the tip of an insert assist tool (also referred to as an overtube or a sliding tube). The first and second balloons can be inflated to secure the insert portion and the insert assist tool in the intestinal tract of the small intestine or the like. Therefore, by repeating inflation and deflation of the first and second balloons and alternately inserting the insert portion and the insert assist tool, the insert portion can be inserted deep into the intestinal tract of the small intestine or the like that bends in a complex manner. 
       SUMMARY OF THE INVENTION 
       [0006]    The endoscope apparatus described in Japanese Patent Application Laid-Open No. 2005-230083 is problematic in that the balloons are attached in such a way that they overlap with a bending portion of the endoscope, so that inflating the balloons results in poor operability of the bending portion. 
         [0007]    Although it is desired that each of the balloons is attached in such a way that it does not overlap with the bending portion of the endoscope, both ends of the balloon cannot be fixed because of a short axial length of a hard portion (hereinafter referred to as a distal end) distal from the bending portion. To attach the balloon to a soft portion proximal from the bending portion, a hard ring needs to be provided inside the soft portion so as to form an opening for supplying and sucking fluid, disadvantageously resulting in an increased number of parts and poor flexibility of the soft portion. 
         [0008]    The present invention has been made in view of such circumstances and aims to provide an endoscope that provides not only good bending operability when the balloon is inflated but also good flexibility of the soft portion. 
         [0009]    To achieve the above object, a first aspect of the present invention provides an endoscope including an insert portion having a bending portion for bending operation and a flexible soft portion connected to the proximal end of the bending portion, an inflatable/deflatable balloon attached on the proximal side from the bending portion, and a supplying/sucking opening provided in the outer surface of a ring that connects the bending portion to the soft portion, the supplying/sucking opening supplying and sucking fluid to and from the balloon. 
         [0010]    According to the first aspect of the present invention, since the balloon is attached on the proximal side from the bending portion, the bending operability of the bending portion may not be compromised when the balloon is inflated. Furthermore, according to the first aspect of the present invention, since the ring that connects the bending portion to the soft portion is used to provide the opening for supplying/sucking fluid, there is no need to separately provide a ring for the supplying/sucking opening in the soft portion, so that the flexibility of the soft portion may not be compromised. Therefore, according to the first aspect of the present invention, the bending operability when the balloon is inflated can be improved and the flexibility of the soft portion can be improved. 
         [0011]    According to the present invention, since the balloon is attached on the proximal side from the bending portion and the opening for supplying/sucking fluid is provided in the ring that connects the bending portion to the soft portion, the bending operability when the balloon is inflated can be improved and the flexibility of the soft portion can be improved. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a system configuration diagram of an endoscope apparatus to which the endoscope according to the present invention is applied; 
           [0013]      FIG. 2  is a side view showing an insert portion of the endoscope; and 
           [0014]      FIG. 3  is a cross-sectional view of the insert portion at the position where a balloon is attached. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0015]    A preferred embodiment of the endoscope according to the present invention will be described below in detail with reference to the accompanying drawings. 
         [0016]      FIG. 1  is a system configuration diagram showing an example of an endoscope apparatus to which the endoscope according to the present invention is applied. As shown in  FIG. 1 , the endoscope apparatus primarily includes an endoscope  10  and a balloon controller  100 . 
         [0017]    The endoscope  10  includes an operator-side manipulator  14  and an insert portion  12  that is connected to the operator-side manipulator  14  and inserted into a body cavity. The operator-side manipulator  14  is connected to a universal cable  16 , and an LG connector  18  is provided at the tip of the universal cable  16 . The LG connector  18  is removably connected to a light source  20  in such a way that illumination light is transmitted to an illumination optical system (not shown) provided at the tip of the insert portion  12 . The LG connector  18  is also connected to an electric connector  24  via a cable  22 , and the electric connector  24  is removably connected to a processor  26 . 
         [0018]    The operator-side manipulator  14  not only has an air-supply/water-supply button  28 , a sucking button  30 , a shutter button  32  and a function switching button  34  juxtaposed but also includes a pair of angle knobs  36 / 36 . A balloon air supply port  38  formed of an L-shaped tube is provided at the proximal end of the operator-side manipulator  14 . Fluid, such as air, supplied into or sucked from the balloon air supply port  38  can inflate or deflate a balloon  60 , which will be described later. 
         [0019]    The insert portion  12  includes a soft portion  40 , a bending portion  42  and a distal end  44  in this order from the operator-side manipulator  14  side. The soft portion  40  is configured such that the outer surface of a spirally wound metal plate is covered with a net and the outer surface of the net is further covered with a coating so as to provide sufficient flexibility. The soft portion  40  is connected to the proximal end of the bending portion  42  in such a way that the soft portion  40  and the bending portion  42  are connected to each other via a connection ring  41 , which will be described later (see  FIG. 3 ). 
         [0020]    The bending portion  42  is configured to be remotely bent by pivoting the angle knobs  36 / 36  on the operator-side manipulator  14 . For example, the bending portion  42  is configured such that a plurality of tubular node rings  51  (see  FIG. 3 ) are pivotally connected to each other by means of guide pins  52  and a plurality of manipulation wires  53  are inserted into the node rings  51  and guided through the guide pins  52 . Pushing and pulling the manipulation wires  53  pivots the node rings  51 / 51  with respect to each other so as to bend the bending portion  42 . By bending the bending portion  42 , the distal end  44  can be oriented in a desired direction. 
         [0021]    Although the configuration of the distal end  44  is not illustrated in the drawings, for example, an observation optical system, an illumination optical system, an air-supply/water-supply nozzle and a forceps opening are provided in the front surface of the distal end  44 . A CCD is disposed behind the observation optical system, and a signal cable is connected to a substrate that supports the CCD. The signal cable is inserted into the insert portion  12 , the operator-side manipulator  14 , the universal cable  16  and the like, extends to the electric connector  24  and is connected to the processor  26 . Therefore, an image for observation acquired through the observation optical system is focused onto the light receiving surface of the CCD and converted into an electric signal. The electric signal is then outputted to the processor  26  via the signal cable and converted into an image signal. In this way, the image for observation is displayed on a monitor  50  connected to the processor  26 . 
         [0022]    The exit end of a light guide is disposed behind the illumination optical system. The light guide is inserted into the insert portion  12 , the operator-side manipulator  14  and the universal cable  16 , and the entrance end of the light guide is disposed in the LG connector  18 . Therefore, by connecting the LG connector  18  to the light source  20 , the illumination light emitted from the light source  20  is transmitted to the illumination optical system through the light guide and emitted forward from the illumination optical system. 
         [0023]    The air-supply/water-supply nozzle communicates with a valve that is operated by the air-supply/water-supply button  28 , and the valve communicates with an air-supply/water-supply connector  48  provided on the LG connector  18 . The air-supply/water-supply connector  48  is connected to an air-supply/water-supply device (not shown) for supplying air and water. Therefore, by operating the air-supply/water-supply button  28 , air or water can be injected out of the air-supply/water-supply nozzle toward the observation optical system. 
         [0024]    The forceps opening communicates with a forceps insert portion  45 . Therefore, by inserting a treatment tool, such as forceps, into the forceps insert portion  45 , the treatment tool can be introduced out of the forceps opening. The forceps opening also communicates with a valve that is operated by the sucking button  30 , and the valve is connected to a sucking connector  49  on the LG connector  18 . Therefore, by connecting a sucking device (not shown) to the sucking connector  49  and using the sucking button  30  to operate the valve, a diseased portion and the like can be sucked into the forceps opening. 
         [0025]    As shown in  FIG. 2 , a balloon  60  made of elastic material, such as rubber, is attached to the outer surface of the insert portion  12 . The balloon  60  is formed into a substantially tubular shape having drawn ends and has small-diameter ends  60 A and  60 B as well as a central inflated portion  60 C. After the insert portion  12  is inserted into the balloon  60  and the balloon  60  is disposed at a predetermined position (the soft portion  40 ) on the insert portion  12 , rubber fixing rings (not shown) are fit onto the ends  60 A and  60 B to fix the balloon  60  to the insert portion  12 . It is noted that the method for fixing the ends  60 A and  60 B is not limited to this specific method, but the ends  60 A and  60 B may be fixed by winding threads. 
         [0026]    The balloon  60  is disposed and fixed on the proximal side from the bending portion  42 . Specifically, the distal end  60 A of the balloon  60  is fixed to the connection ring  41  disposed between the bending portion  42  and the soft portion  40 , while the proximal end  60 B is fixed to the soft portion  40 . 
         [0027]    As shown in  FIG. 3 , the connection ring  41  is a metal ring for connecting the most proximal node ring  51  of the bending portion  42  to the distal end of the soft portion  40 . The node ring  51  of the bending portion  42  and the distal end of the soft portion  40  are fixed to the connection ring  41 . 
         [0028]    A supplying/sucking opening  46  is formed in the outer surface of the connection ring  41 . The supplying/sucking opening  46  communicates with a hole  43  formed diagonally with respect to the axial direction of the connection ring  41 , and the hole  43  is connected to a pipe  55 . The inner portion of the connection ring  41  is thick at the position of the hole  43 , allowing reliable connection to the pipe  55 . 
         [0029]    The pipe  55  is bent at some midpoint along its length. The pipe  55  is disposed such that a proximal end  55 A is parallel to the axis of the connection ring  41  (longitudinal axis of the soft portion  40 ), and the end  55 A is connected to a flexible tube  56 . The tube  56  is inserted into the soft portion  40  and communicates with the balloon air supply port  38  of the operator-side manipulator  14  shown in  FIG. 1 . The balloon air supply port  38  is connected to the balloon controller  100  via a tube  110 , which will be described later. Therefore, the balloon controller  100  can supply or suck air to inflate or deflate the balloon  60 . The balloon  60  is configured such that supplying air inflates the balloon  60  into a substantially spherical shape, while sucking air allows the balloon  60  to stick on the outer surface of the insert portion  12 . 
         [0030]    The outer surface (exposed surface) of the connection ring  41  shown in  FIG. 3  is coated with non-conductive material, such as fluororesin, in order to ensure safety when a high-frequency treatment tool is used. Furthermore, a circumferential groove may also be formed in the outer surface of the connection ring  41  and at the position where the end  60 A of the balloon  60  is attached, so that the fixed end  60 A will not project from the outer surface. 
         [0031]    The balloon controller  100  shown in  FIG. 1  is an apparatus that supplies and sucks fluid, such as air, to and from the balloon  60 . The balloon controller  100  primarily includes an apparatus body  102  and a hand switch  104  for remote control. 
         [0032]    A power supply switch SW 1 , a stop switch SW 2  and a pressure display  106  are provided on the front side of the apparatus body  102 . The pressure display  106  is a panel that displays the pressure value in the balloon  60 . When the balloon  60  is under abnormal conditions, such as when the balloon is broken, the pressure display  106  displays an error code. 
         [0033]    The tube  110  that supplies and sucks air to and from the balloon  60  is connected to the front side of the apparatus body  102 . A reverse flow prevention unit  112  is provided at the portion where the tube  110  is connected to the apparatus body  102  in order to prevent a reverse flow of body fluid when the balloon  60  is broken. The reverse flow prevention unit  112  is configured by incorporating a gas-liquid separation filter in a hollow disc-shaped case (not shown) removably mounted in the apparatus body  102 . The reverse flow prevention unit  112  uses the filter to prevent liquid from flowing into the apparatus body  102 . 
         [0034]    On the other hand, various switches are provided on the hand switch  104 . For example, there are provided a stop switch similar to the stop switch SW 2  on the apparatus body  102 , an ON/OFF switch that instructs to pressurize/depressurize the balloon  60 , a pause switch for maintaining the pressure in the balloon  60  and the like. The hand switch  104  is electrically connected to the apparatus body  102  via an electric code  130 . Although not shown in  FIG. 1 , the hand switch  104  includes a display that indicates that air has been supplied to the balloon  60  or that air has been evacuated from the balloon  60 . 
         [0035]    The thus configured balloon controller  100  supplies air to the balloon  60  to inflate it and controls the air pressure in the balloon  60  to be a fixed value so as to keep the balloon  60  inflated, while the balloon controller  100  sucks the air from the balloon  60  to deflate it and controls the air pressure in the balloon  60  to be a fixed value so as to keep the balloon  60  deflated. 
         [0036]    The balloon controller  100  is connected to a dedicated balloon monitor  82  and displays the pressure value and the state of the balloon  60 , either inflated or deflated, on the dedicated balloon monitor  82  when the balloon  60  is inflated or deflated. Alternatively, the pressure value and the state of the balloon  60 , either inflated or deflated, may be displayed on the monitor  50  by superimposing the information on an image for observation acquired through the endoscope  10 . 
         [0037]    As an example of a method for operating the thus configured endoscope apparatus, the insert portion  12  is inserted by a pushing movement and the balloon  60  is inflated as required to secure the insert portion  12  in the body (such as the large intestine). Then, after the insert portion  12  is pulled to simplify the shape of a tract in the body (such as the large intestine), the balloon  60  is deflated and the insert portion  12  is inserted even deeper into the intestinal tract. For example, the insert portion  12  is inserted into the anus of the patient. When the tip of the insert portion  12  passes the sigmoid colon, the balloon  60  is inflated to secure the insert portion  12  in the intestinal tract. Then, the insert portion  12  is pulled to substantially straighten the sigmoid colon. Thereafter, the balloon  60  is deflated and the tip of the insert portion  12  is inserted deeper into the intestinal tract. In this way, the insert portion  12  can be inserted deep into the intestinal tract. 
         [0038]    The effects of the thus configured endoscope  10  will now be described. 
         [0039]    The balloon  60  of the endoscope  10  is configured such that the distal end  60 A is fixed to the connection ring  41  and the proximal end  60 B is fixed to the soft portion  40 . Therefore, unlike when the end  60 A or  60 B of the balloon  60  is fixed on angle rubber  54  on the bending portion  42 , the angle rubber  54  may not be pressed or damaged, or the node rings  51 / 51  may not sandwich and damage the angle rubber  54  during bending operation. Therefore, according to this embodiment, the angle rubber  54  will not be damaged. 
         [0040]    Furthermore, according to this embodiment, the balloon  60  is disposed on the proximal side from the bending portion  42 . Therefore, as indicated by the two-dot chain lines in  FIG. 2 , even when the balloon  60  is inflated, the bending portion  42  can be freely bent. Therefore, according to this embodiment, bending operability can be improved when the balloon  60  is inflated. 
         [0041]    Moreover, according to this embodiment, the connection ring  41  between the bending portion  42  and the soft portion  41  is used to form the fluid supplying/sucking opening  46 . Therefore, unlike when the supplying/sucking opening  46  is provided in the soft portion  40 , there is no need to newly provide a sleeve, allowing the number of parts to be reduced. Furthermore, as compared to the case where the supplying/sucking opening  46  is provided in the soft portion  40 , absence of sleeve can improve the flexibility of the soft portion  40 . 
         [0042]    In the embodiment described above, although the outer surface of the connection ring  41  is coated with non-conductive material, the connection ring  41  may be covered with a cladding member and a hole is formed in the cladding member such that the hole communicates with the supplying/sucking opening  46 , as far as this configuration ensures safety when a high-frequency treatment tool is used.