Abstract:
A balloon control device for controlling an expansion and contraction of a balloon fixed to one of an insertion unit of endoscope and an insertion adapter by supplying and suctioning of fluid to the balloon, comprising: a channel for conveying the fluid between the balloon control device and the balloon; and a gas/liquid separator for separating gas and liquid from the fluid in the channel.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a balloon control device, and more particularly to a balloon control device for controlling a balloon installed to an insertion unit of endoscope and an insertion adapter.  
         [0003]     2. Description of the Related Art  
         [0004]     As disclosed in Japanese Patent Application Publication No. 2003-144378, an endoscope system using balloon is developed recently. In this case, the balloon is attached around the tip of an insertion unit of endoscope, or the tip of an insertion adapter in which covers on the insertion unit. Therefore, the insertion unit or the insertion adapter is fixed within the body cavity by expanding the balloon within the body cavity.  
         [0005]     The insertion unit and the insertion adapter are provided an air supply intake port communicating with the balloon at the base end of those. The air supply intake port is connected to a balloon control device by a tube. Air is supplied and sucked to the tube at the balloon control device so that the balloon is expanded and contracted.  
         [0006]     However, the conventional balloon control device has a possibility that an unclean matter such as body fluid is sucked into the device through the tube when the balloon is broken or when the connection of the tube is bad. In such case, an electromagnetic valve and a pump within the balloon control device are damaged by the unclean matter. In order to cope with this problem, it is necessary that the balloon control device is provided with a fluid reservoir such as a trap. However, whenever the unclean matter is sucked, it is necessary to wash and sterilize the trap. This maintenance work has a problem of taking great deal of time and labor.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention was contrived in view of such circumstances, and an object thereof is to provide a balloon control device capable of preventing unclean matter from being sucked into it and permitting easy maintenance in terms of washing and sterilization.  
         [0008]     To achieve the above-stated object, a first aspect of the present invention is directed a balloon control device for controlling an expansion and contraction of a balloon fixed to one of an insertion unit of endoscope and an insertion adapter by supplying and suctioning of fluid to the balloon, comprising: a channel for conveying the fluid between the balloon control device and the balloon; and a gas/liquid separator for separating gas and liquid from the fluid in the channel.  
         [0009]     According to the first aspect of the invention, since the gas/liquid separator is provided with the fluid channel of the balloon control device, the sucked liquid is separated from air by the gas/liquid separator. Therefore, it is possible to prevent the liquid from being sucked into the balloon control device.  
         [0010]     A second aspect of the invention is directed the balloon control device as defined in the first aspect, wherein the gas/liquid separator is one of a gas/liquid separation filter, a water-absorbent polymer member, a paper fiber member, a water-absorbent fiber member, and a liquid reservoir tank.  
         [0011]     A third aspect of the invention are directed the balloon control device as defined in the first aspect, further comprising: a tube as the channel for linking between the balloon control device and the balloon; a body of the balloon control device; and a coupling for connecting the tube to the body, wherein the gas/liquid separator being disposed on both of an inside of the body and a coupling.  
         [0012]     A fourth aspect of the invention is directed the balloon control device as defined in the third aspect, wherein the tube is linked to the gas/liquid separator with a lure lock mechanism. Therefore, according to the invention, the gas/liquid separator and the tube can be easily linked with each other in an airtight state.  
         [0013]     A fifth aspect of the invention is directed the balloon control device as defined in the fourth aspect, further comprising a hollow portion for installing the gas/liquid separator into the body. Therefore, according to the sixth aspect of the invention, since the gas/liquid separator is installed in the hollow portion in the body of the balloon control device, the gas/liquid separator does not protrude when it is installed to the body, and the device can be made compact.  
         [0014]     Sixth and seventh aspects of the invention is directed the balloon control device as defined in the first and third aspects, wherein the gas/liquid separator is formed by laminating a water-absorbent member on inner surface of the tube. Therefore, according to the sixth aspect of the invention, as it is required only to provide the tube on the channel by which the balloon and the balloon control device communicate with each other, the device can be simplified and made compact.  
         [0015]     Eighth to tenth aspects of the invention are directed the balloon control device as defined in the first, third, and sixth aspects, further comprising a liquid detector for detecting liquid in the gas/liquid separator. Therefore, according to the Eighth to eleventh aspects of the invention, since the arrival of any liquid at the liquid detecting device can be known, the timing for the replacement, maintenance or washing of the gas/liquid separator can be known accurately.  
         [0016]     Eleventh to thirteenth aspects of the invention is directed the balloon control device as defined in the eighth to tenth aspects, wherein the liquid detector has a component to change color when liquid is detected. Therefore, according to the eighth aspect of the invention, the presence or absence of liquid can be checked by a color change of the liquid detecting device.  
         [0017]     Therefore, according to the balloon control device of the present invention, it is possible to prevent liquid in fluid from getting into the balloon control device by disposing the gas/liquid separator, effectively. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]     The nature of this invention, as well as other objects and advantages thereof, will be explained in the following with reference to the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures and wherein:  
         [0019]      FIG. 1  is a schematic perspective diagram of an endoscope system according to an embodiment of the present invention;  
         [0020]      FIG. 2  is a perspective diagram showing a tip portion of an insertion unit according to an embodiment of the present invention;  
         [0021]      FIG. 3  is a schematic block diagram of an endoscope system according to an embodiment of the present invention;  
         [0022]      FIG. 4  is a perspective view of a balloon control device according to an embodiment of the present invention;  
         [0023]      FIG. 5  is a side cross-sectional view of a filter unit according to an embodiment of the present invention;  
         [0024]      FIG. 6  is a schematic perspective view of the endoscope system with a balloon installed to an insertion adapter;  
         [0025]      FIG. 7  is a schematic perspective view of the endoscope system with a balloon installed to an insertion adapter and an insertion unit;  
         [0026]      FIG. 8  is a schematic plan view of a gas/liquid separator according to another embodiment of the present invention;  
         [0027]      FIG. 9  is a schematic plan view of a gas/liquid separator according to still another embodiment of the present invention;  
         [0028]      FIG. 10  is a schematic plan view of a gas/liquid separator according to further embodiment of the present invention;  
         [0029]      FIG. 11  is a cross-sectional view of a gas/liquid separator according to still further embodiment of the present invention;  
         [0030]      FIG. 12  is a schematic plan view of a gas/liquid separator equipped with a liquid detecting device according to an embodiment of the present invention; and  
         [0031]      FIG. 13  is a schematic plan view of a gas/liquid separator equipped with a liquid detecting device according to another embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0032]      FIG. 1  is a schematic perspective view of an endoscope system according to an embodiment of the present invention. As shown in  FIG. 1 , the endoscope system is mainly comprised an endoscope  10 , a light equipment  20 , a processor  30 , and a balloon control device  100 .  
         [0033]     The endoscope  10  is composed of an insertion unit  12  to be inserted into a body cavity, and a handy control unit  14  linked to the insertion unit  12 . The insertion unit  12  and the handy control unit  14  are connected by a universal cable  16 . While an LG connector  18  is provided at the tip of the universal cable  16 , the LG connector  18  is connected to the light equipment  20 . While an electrical connector  24  is connected to the LG connector  18  via a cable  22 , the electrical connector  24  is linked to the processor  30 . A gas feed/water feed tube  26  for supplying air or water, and a suction tube  28  for sucking air and body fluid are connected to the LG connector  18 .  
         [0034]     The handy control unit  14  is equipped with a gas feed/water feed button  32 , a suction button  34  and a shutter release button  36 , and is also provided with a pair of angle knobs  38  and  38 , and a forceps insertion unit  40 . At the base end portion of the handy control unit  14 , a feed/suction port  44  is provided to facilitate gas supply to and gas suction from a balloon  42  as described later. The following description supposes the use of air as gas, but some other gas, such as inert gas, may be used as well.  
         [0035]     The insertion unit  12  is composed of a tip portion  46 , a curved portion  48 , and a soft portion  50 . The curve of the curved portion  48  is controlled remotely by turning the pair of angle knobs  38  and  38  in the handy control unit  14 . Therefore, it is possible to turn the tip face  47  of the tip portion  46  into a desired direction.  
         [0036]     As shown in  FIG. 2 , the tip face  47  of the tip portion  46  is provided with an observational optical unit  52 , a plurality of illuminating optical units  54 , a gas feed/water feed nozzle  56 , and a forceps port  58 . As not shown in  FIG. 2 , a CCD is arranged behind the observational optical unit  52  (i.e., opposite to the side of the tip face  47  in the observational optical unit  52 ), and a signal cable is connected to a substrate holding the CCD. The signal cable is extended to the electrical connector  24  while inserted into the insertion unit  12 , the handy control unit  14  and the universal cable  16  shown in  FIG. 1 , and is connected to the processor  30 . In this case, an observing image taken at the observational optical unit  52  is converted into an electrical signal by forming an image on the light receiving face of the CCD, and then the electrical signal is supplied to the processor  30  via the signal cable to be converted into an image signal. Therefore, the observed image is displayed on a monitor  60  connected to the processor  30 .  
         [0037]     The emitting end of a light guide (not shown) is arranged behind the illuminating optical units  54  in  FIG. 2  (i.e., opposite to the side of the tip face  47  on the illuminating optical units  54 ). The light guide is inserted into the insertion unit  12 , the handy control unit  14 , and the universal cable  16  in  FIG. 1 . The incidence end is arranged on the LG connector  18 . Therefore, the illuminating optical units  54  irradiate the illuminating light emitted from the light equipment  20  via a light guide (not shown).  
         [0038]     The gas feed/water feed nozzle  56  (referred in  FIG. 2 ) is connected to the gas feed/water feed tube  26  while the gas feed/water feed nozzle  56  (referred in  FIG. 2 ) is connected to a valve (not shown) manipulated with the gas feed/water feed button  32 . Therefore, air or water is discharged from the gas feed/water feed nozzle  56  toward the observational optical unit  52  by operating the gas feed/water feed button  32 .  
         [0039]     While the forceps port  58  in  FIG. 2  is linked to a forceps insertion unit  40 , the forceps port  58  is connected to a valve (not shown) operated by the suction button  34 . In addition, the forceps port  58  is further connected to the suction tube  26 . Therefore, a lesion and the like is sucked from the forceps port  58  by operating the suction button  34 , and a treating tool (not shown) is guided out through the forceps port  58  by inserting through the forceps insertion unit  40 .  
         [0040]     As shown in  FIG. 2 , the balloon  42  consisting of an elastic material such as rubber is installed around the part of the insertion unit  12 . It is formed in a substantially cylindrical shape with its two ends narrowed. The balloon  42  is fixed by fixing the two ends to the insertion unit  12  after it is inserted through the insertion unit  12 . The two ends of the balloon  42  is fixed by, for instance, winding a thread around each end part of the balloon  42 , and both ends of the balloon  42  are thereby fastened to the full outer circumference of the insertion unit  12 . Instead of winding a thread, a fixed ring of rubber, and the like may be installed onto each end of the balloon  42 .  
         [0041]     A ventilation port  62  is formed in the installing position for the balloon  42  on the insertion unit  12 . This ventilation port  62  is connected to the feed/suction port  44  via a tube  66  (see  FIG. 3 ) inserted into the insertion unit  12 . The tip of a tube  64  is linked to the feed/suction port  44 , and the base end of this tube  64  is connected to the balloon control device  100  to be described in further detail afterwards. The balloon control device  100  feeds air to and sucks air from the balloon  42  via the tubes  64  and  66 , and thereby controls the expansion or contraction of the balloon  42 . The balloon  42  inflates into a substantially spherical shape when fed with air and sticks to the outer surface of the insertion unit  12  when air is sucked out of it.  
         [0042]      FIG. 3  is a schematic block diagram of an endoscope system according to an embodiment of the present invention, showing air channel simply.  FIG. 4  is a perspective view of a balloon control device  100  according to an embodiment of the present invention.  
         [0043]     As shown in  FIG. 3 , a gas feed pump  104 , a suction pump  106 , a first on/off electromagnetic valve  108 , a second on/off electromagnetic valve  110 , and a change-over electromagnetic valve  112  are disposed within the body  102  of the balloon control device  100 . While a gas feed duct  114  is connected to the gas feed pump  104 , the gas feed duct  114  is connected to the change-over electromagnetic valve  112  via the on/off electromagnetic valve  108 . While a suction duct  116  is connected to the suction pump  106 , the suction duct  116  is connected to the change-over electromagnetic valve  112  via the second on/off electromagnetic valve  110 . While the change-over electromagnetic valve  112  is connected to a connection port  120  via a duct  118 , the connection port  120  is connected to the tube  64  via a filter unit  150  as described later.  
         [0044]     The change-over electromagnetic valve  112  has a configuration in which the duct  118  is connected to one of the gas feed duct  114  and the suction duct  116 . For example, in the case feeding air to the balloon  42 , the change-over electromagnetic valve  112  is controlled to connect the gas feed duct  114  with the duct  118 . On the other hand, in the case sucking air from the balloon  42 , the change-over electromagnetic valve  112  is controlled to connect the suction duct  116  with the duct  118 . Furthermore, when electric power supply is off, the change-over electromagnetic valve  112  makes the suction duct  116  connected with the duct  118 , so as to prevent the balloon  42  from expanding in an unusual situation such as a power failure.  
         [0045]     The first and second on/off electromagnetic valves  108  and  110  control the opening and closing of the gas feed duct  114  and the suction duct  116 , respectively. When the power supply is off, the gas feed duct  114  and the suction duct  116  are closed. It is possible that feeding air and operating to suction are temporarily suspended by controlling on/off of the first and second on/off electromagnetic valves  108  and  110 . When the value of a pressure gauge  124  reached the set level in expanding the balloon  42 , air supply is temporarily suspended by closing the first on/off electromagnetic valve  108 . On the other hand, when the value of the pressure gauge  124  falls below the set level, air supply is resumed by opening the first on/off electromagnetic valve  108 . Therefore, the internal pressure of the balloon  42  can be securely maintained at the set level. In the case in which the diameter of the tube  66  is smaller than that of the tube  64 , the value of the pressure gauge  124  is different to the actual internal pressure of the balloon  42 . Therefore, the first on/off electromagnetic valve  108  as described above may maintain the internal pressure of the balloon  42  at the setting value, exactly. In the same way, when the balloon  42  is to be contracted, the suction of air is temporarily stopped and resumed by closing or opening the second on/off electromagnetic valve  110 , so as to maintain the internal pressure of the balloon  42  at the setting value.  
         [0046]     As shown in  FIG. 4 , a remote controller  128  is connected to the body  102  of the balloon control device  100  via a cable  126 . The remote controller  128  is provided with a power switch  130  and a plurality of first control buttons  132  for altering the setting value of the pressure in the balloon  42 , and for turning the supplying and sucking of air.  
         [0047]     A balloon monitor  136  is connected to the body  102  via a cable  134 . The balloon monitor  136  is provided with a status display unit  136 A and an error display unit  136 B. The status display unit  136 A displays the status of the expanded or contracted balloon  42 , and the error display unit  136 B displays an error message in the error. Since the balloon monitor  136  is detachably installed to the monitor  60  in  FIG. 1 , it is possible to check the status of balloon  42  and any error message on the balloon monitor  136  while the image taken by the endoscope  10  is observed on the monitor  60 . The balloon control device  100  according to the invention is not limited to above, and the status of balloon  42  and the error message may be displayed on the monitor  60  instead of the balloon monitor  136 . The remote controller  128  may be provided with a display screen for displaying the status of balloon  42  and the error message. Furthermore, the status of balloon  42  and any error message may be displayed on the monitor  60  as the superimpose on the endoscopic image by entering image signal from the endoscope  10  into the balloon control device  100 .  
         [0048]     As shown in  FIG. 4 , a power switch  138  and various control buttons  140  are disposed on the front panel  102 A of the body  102 . Since the second control buttons  140  have the same functions as the first control buttons  132  of the remote controller  128 , it is possible that the balloon control device  100  is operated by the first and second control buttons  132  and  140 .  
         [0049]     In addition, the front panel  102 A is provided with a balloon display unit  142  for displaying the status of balloon  42  and an error display unit  144  for displaying any error message. Therefore, it is possible to check the status of balloon  42  and the error message by looking at the front panel  102 A. The front panel  102 A is also provided with a pressure display unit  146  to enable the value of the pressure gauge  124  (referred in  FIG. 3 ) to be displayed.  
         [0050]     A disk-shaped concave receptacle  148  is formed in the front panel  102 A in the position of connection with the tube  64 , and a filter unit  150  is detachably installed and accommodated in the receptacle  148 .  
         [0051]     As shown in  FIG. 4  and  5 , the filter unit  150  is composed of a hollow casing  152  and a disk-shaped membrane filter  154  (hereinafter referred to as filter  154  simply). While the casing  152  has substantially a disk shape, the filter  154  is arranged within the casing  152 . A cylindrical linking portion  156  is projected on the back central part of the casing  152  (i.e., the side toward the body  102 ). When the linking portion  156  is fitted into the connection port  120  of the body  102 , the interior of the casing  152  is connected to the connection port  120  while the casing  152  installed to the body  102  is accommodated in the receptacle  148 .  
         [0052]     The method of fixing the casing  152  to the body  102  is not limited to above embodiment. For example, it may be suitable that a catching projection formed on the outer circumference of the casing  152  is set to a catching groove formed on a side of the receptacle  148 . In the case of the connection port  120  consisting of a rubber or some other elastic member, it is possible to fix the connection port  120  in the casing  152  stability by the elasticity of those when inserting the connection port  120  into the linking portion  156 . Furthermore, the connection port  120  and the linking portion  156  may be linked with a lure lock mechanism as described later.  
         [0053]     A cylindrical linking portion  158  is formed by projecting on the central part of the surface of the casing  152 . It is preferable that the linking portion  158  has a structure to ensure linking with the tube  64  in an airtight state, and for example, a lure lock mechanism is used in the embodiment. In other words, as shown in  FIG. 5 , a flange  160  is protrusively formed on the outer circumference of the end part of the linking portion  158 , and a female screw  162 A with which the flange  160  is to engage is formed in the inner circumferential face of the connector  162  of the tube  64 . By engaging the flange  160  with the female screw  162 A, the linking portion  158  and the connector  162  are linked in a sustained airtight state. Incidentally, a female screw may as well be formed on the linking portion  158 , and a flange formed on the connector  162  of the tube  64 .  
         [0054]     A filter  154  arranged within the casing  152  is formed at an outer diameter equal to the inner diameter of the casing  152 , and the whole fluid passing the inside of the casing  152  passes the filter  154 . The filter  154  is so configured as not to pass liquid but to pass only gas. As any liquid passing the casing  152  is collected by the filter  154 , liquid can be prevented from passing the casing  152 . A radial straightening device can also be disposed within the casing  152  so that air can pass uniformly over the whole face of the filter  154 .  
         [0055]     Next, the action of the balloon control device  100  as configured above is described following.  
         [0056]     The balloon control device  100  can control the expansion, the contraction, and the stopping according to the balloon  42 , by manipulating the first control buttons  132  and the second control buttons  140 .  
         [0057]     For example, in the case of expanding the balloon  42 , the first on/off electromagnetic valve  108  is opened while the gas feed pump  104  in  FIG. 3  is driven, and then the change-over electromagnetic valve  112  is changed over to the side of the gas feed duct  114 . Therefore, air fed from the connection port  120  is supplied to the balloon  42  via the tubes  64  and  66 .  
         [0058]     Next, the pressure value in the balloon  42  is controlled at the set level by opening and closing the first on/off electromagnetic valve  108  according to the value of the pressure gauge  124 . Therefore, the balloon  42  is expanded at the internal pressure controlled to the set level.  
         [0059]     In the case of contracting the balloon  42 , the second on/off electromagnetic valve  110  is opened while the suction pump  106  is driven, and then the change-over electromagnetic valve  112  is changed over to the side of the suction duct  116 . Therefore, air in the balloon  42  is sucked into the connection port  120  via the tubes  64  and  66 .  
         [0060]     Next, the internal pressure of the balloon  42  is controlled at the set level by opening and closing the second on/off electromagnetic valve  110  according to the value of the pressure gauge  124 . Therefore, the balloon  42  is contracted at the internal pressure controlled to the set level.  
         [0061]     In the case of unusual situation during the expanding and contracting operation as described above, while the balloon control device  100  is stopped the operation, an error message is displayed during the unusual situation on the error display units  144  and  136 B. In this case, it is preferable for the type of the error that has occurred to be identified and to display the identified error type. For example, when the value of the pressure gauge  124  is above the preset threshold of unusual pressure, the situation is identified as one of an unusual pressure resulting from the working of an undue force on the balloon  42 , and that finding is displayed on the error display units. On the other hand, when the value of the pressure gauge  124  fails to vary to the set level in a prescribed period of time, the cause is determined to be faulty connection of the tube  64 , and that finding is displayed on the error display units.  
         [0062]     Furthermore, when the first and/or second on/off electromagnetic valves  108  and/or  110  are frequently changed over in a prescribed period of time (e.g. 40 seconds), it will be judged that the balloon  42  has been broken and an error message to that effect will be displayed on the error display units. In the case in which the balloon  42  is broken, the internal pressure of the balloon  42  will soon vary even if the value of the pressure gauge  124  reaches the set value and the first and second on/off electromagnetic valves  108  and  110  are closed. Therefore, it is necessary to open the first and second on/off electromagnetic valves  108  and  110  again for feeding and sucking air. In this time, the first and second on/off electromagnetic valves  108  and  110  repeated the opening and closing. Therefore, it is possible to detect the breaking of the balloon  42  by counting how many times they are opened and closed.  
         [0063]     In the case in which the balloon  42  is broken during the contracting process, there is some possibility of sucking liquid such as body fluid into the balloon  42  via the tubes  64  and  66 . Therefore, the conventional balloon control device has a problem in which the change-over electromagnetic valve  112  and the suction pump  106  in the body  102  are damaged by the sucked liquid. In the embodiment of present invention, it is possible to solve such a problem by providing with the filter unit  150 . In other words, the liquid sucked via the tube  64  is removed by the filter  154  when it has reached the filter unit  150 . The removed liquid is stored in a space  150 A (referred in  FIG. 5 ) located closer to the linking portion  158  than the filter  154  in the casing  152 . Therefore, there is no fear of liquid being sucked into the body  102 , and the change-over electromagnetic valve  112  and the suction pump  106  in the body  102  are prevented from damage.  
         [0064]     As described above, the balloon control device  100  according to embodiment of the invention can prevent liquid from being sucked into the body  102  by virtue of the presence of the filter unit  150  between the body  102  and the tube  64 .  
         [0065]     In addition, since the filter unit  150  is disposed to be detachable from the body  102  in the embodiment of the invention, the filter unit  150  can be removed from the body  102  to facilitate its sterilization and disinfection. Therefore, the filter unit  150  can be replaced as a disposable item.  
         [0066]     In the embodiment, since the filter unit  150  is linked to the tube  64  with a lure lock mechanism, it is possible to install the filter unit  150  easy by pressing the base end of the tube  64  into the linking portion  158  of the filter unit  150  while rotating it, so that air tightness can be achieved in this process. In addition, the tube  64  can be easily taken off the filter unit  150  by pulling the base end of the tube  64  while rotating it. Therefore, the tube  64  can be removed from the filter unit  150  to facilitate sterilization and disinfection of the tube  64  alone.  
         [0067]     Additionally, although the filter unit  150  and the tube  64  are linked with each other by using a lure lock mechanism in the embodiment described above, they may be linked in some other way. For example, since the filter unit  150  is alternately formed circular convexes and concaves on the outer circumferential face of the linking portion  158 , it is possible to snap the tube  64  on outside the linking portion  158 .  
         [0068]     Furthermore, though the balloon control device  100  described above is supposed to control a balloon  42  installed to the insertion unit  12  of the endoscope  10 , it can also be applied as a device for controlling a balloon installed to an insertion adapter.  
         [0069]      FIG. 6  is a schematic perspective view of the endoscope system with a balloon installed to an insertion adapter.  
         [0070]     As shown in  FIG. 6 , an insertion adapter  70  is formed by protecting the inside and outside of a resin tube, consisting of urethane or the like, with lubricant coats, and exerts a righting moment when an external force is applied to it from the outer circumferential face. The inner diameter of the insertion adapter  70  is greater than the outer diameter of the insertion unit  12  of the endoscope  10 , so that the insertion unit  12  can be inserted into the insertion adapter  70 .  
         [0071]     A ring (not shown), consisting of an X-ray intercepting member of metal or some other material, is disposed at the tip of the insertion adapter  70 , so that the tip position of the insertion adapter  70  can be recognized in roentgenoscopy.  
         [0072]     A second balloon  72  made of rubber is installed around the tip of the insertion adapter  70 . The second balloon  72  is cylindrically shaped like the first balloon  42  shown in  FIG. 3 , and both ends  72 A of the second balloon  72  are fixed to the insertion adapter  70 . Reference numeral  84  in  FIG. 6  denotes a feed port for feeding a lubricant, such as water. By feeding a lubricant through the feed port  84 , the friction between the insertion adapter  70  and the insertion unit  12  can be reduced.  
         [0073]     A tube  76  stuck to the outer surface of the insertion adapter  70  connected to the second balloon  72 , and the tip portion of a tube  80  is detachably linked to a connector  78  disposed at an end of this tube  76 . The base end of the tube  80  is linked to the balloon control device  100 , which feeds air to or sucks air from the tube  80  and can control the air pressure in that process. Therefore, it is possible to feed air to or suck air from the balloon  72 .  
         [0074]     In the balloon control device  100 , as described above, the filter unit  150  is detachably installed to the front panel  102 A of the body  102 . The base end of the tube  80  is linked to the linking portion  158  of the filter unit  150 . The linking portion  158  and the tube  80  are linked to each other by using a lure lock mechanism for instance.  
         [0075]     In the endoscope system configured as described above, too, as the filter unit  150  is disposed on the linking portion between the balloon control device  100  and the tube  80 , the filter unit  150  can remove air sucked by the tube  80 , and thereby prevent the liquid from being further sucked into the body  102 . Therefore, the balloon control device  100  can also be applied as a device for controlling a balloon  72  installed to an insertion adapter  70 .  
         [0076]      FIG. 7  is a schematic perspective view of the endoscope system with a balloon installed to an insertion adapter and an insertion unit. As shown in  FIG. 7 , in the endoscope system, while a first balloon  42  is installed to the insertion unit  12 , a second balloon  72  is installed to the insertion adapter  70 . The balloon control device  100  and two filter units  150  and  150  are detachably installed to the body  102 . While the tube  64  connected to the balloon  42  is linked to the first filter unit  150 , the tube  80  connected to the second balloon  72  is linked to the second filter unit  160 . Within the body  102 , two lines of air pressure control devices are provided to enable the tube  64  and the tube  80  to feed and suck air, respectively.  
         [0077]     In such above endoscope system, liquid sucked via the tubes  64  and  80  can be also removed by the filter units  150  and  150  to prevent liquid from being further sucked into the body  102 . Furthermore, since the filter units  150  and  150  are detachably installed, maintenance work on the filter units  150 , including washing and sterilization, can be easily accomplished.  
         [0078]     Although the embodiment of the invention described above uses the filter units  150  as a gas/liquid separator, the usable gas/liquid separator are not limited to those. For example, water-absorbent polymer, a porous material consisting of polytetrafluoroethylene or the like, paper fibers such as Japanese rice paper, water-absorbent fibers such as cotton wool can be used in place of the filter  154 .  
         [0079]     As shown in  FIG. 8 , a liquid reservoir tank  180  to serve as the trap for liquid can also be used as a gas/liquid separator. The liquid reservoir tank  180  is so installed that two pipes  182  and  183  penetrate a lid  184 . The lower ends of the pipes  182  and  183  are arranged above the liquid surface. The tube  64  (or the tube  80 ) is connected to one pipe  182 , and the other pipe  183  communicates with the duct  118  (see  FIG. 3 ). When liquid and gas flow from the tube  64  into the liquid reservoir tank  180  configured in this way via the pipe  182 , liquid is left in the reservoir tank  180 , and only gas is extracted from the other pipe  183 . Therefore, liquid can be prevented from entering into the body  102 .  
         [0080]     The reservoir tank  180  may as well be configured as shown in  FIG. 9 . The pipes  182  and  183  for the reservoir tank  180  in  FIG. 9  are connected to a bypass pipe  185 , and the bypass pipe  185  is provided with a non-return valve  186  for preventing flow from the pipe  182  to the pipe  183 . The pipe  183  in the reservoir tank  180  is provided with a non-return valve  187  for preventing flow to the reservoir tank  180 . When fluid from the first or second tube  64  or  80  is sucked into the reservoir tank  180  configured in this way, the fluid flows into the reservoir tank  180  via the pipe  182  without passing the bypass pipe  185 , and liquid is separated in the tank and only gas is sucked from the pipe  182 . Therefore, it is possible to prevent liquid from flowing into the body  102 . When air is supplied from the body device  102  to the pipe  183 , the air does not flow into the reservoir tank  180  but into the first or second tube  64  or  80  via the bypass pipe  185 . Accordingly, since the air flows detouring the reservoir tank  180 , it is not pressurized in the reservoir tank  180 , but liquid (body fluid or the like) depositing in the reservoir tank  180  can be prevented from flowing back toward the endoscope  10 .  
         [0081]     In the above-described embodiment, the gas/liquid separator (the filter units  150 ) is disposed in the connecting parts between the body  102  and the tubes  64  and  80 , but the positions of the gas/liquid separator are not limited to those. It is possible to arrange the gas/liquid separator on any appropriate positions in the channel of air sucked from the first and second balloons  42  and  72 . Therefore, they can be arranged midway on the duct  118  or the suction duct  116  within the body  102  or midway on the first and second tubes  64  and  80 .  
         [0082]     As shown in  FIG. 10 , it is also preferable that the filter units  150  are arranged integrally at ends of the tubes  64  and  80 . It is possible to reduce the frequency of linking of the connectors by integral arrangement. In this case, it is preferable to provide the tubes  64  and  80  shown in  FIG. 10  with structures against wrong piping to prevent erroneous linking. Therefore, the tube  64  is provided with a lure taper-shaped male side coupling  190 A at the end toward the filter unit  150  and with a female side coupling  191 B at the other end. The tube  80  is provided with a female side coupling  192 B on the filter  150  side and with a male side coupling  193 A at the other end. The bodies  102  with which the couplings  190 A and  192 B are to be linked are provided with matching female side couplings  190 B and  192 A. The feed/suction port  44  and the connector  78  with which the couplings  191 B and  193 A are to be linked are provided with matching male side coupling  191 A and female side coupling  193 B. Therefore, the configuration in which the male and female couplings are reversely arranged between the tubes  68  and  80  can serve to prevent wrong linking.  
         [0083]     Furthermore, it is preferable to dispose the gas/liquid separator in tubes constituting air channels. In other words, it is preferable to provide the gas/liquid separator within the tubes constituting the duct  118  and the suction duct  116  or the tubes  64  and  80 . In this case, it is preferable to use double-structured tubes  200  each consisting of a waterproof tube shell  201  and a water-absorbent member  202  inside it as shown in  FIG. 11 . Therefore, by the above configuration, it is possible to secure an air channel in the central part  203  of each tube  200  and to separate liquid flowing through the tube  200  by having it absorbed by the water-absorbent member  202 .  
         [0084]     More over, it is preferable for the gas/liquid separator to be provided with a liquid detection device for detecting liquid. For example, the filter unit  150  shown in  FIG. 12  comprises a liquid detecting paper  210  in the space  150 A located closer to the linking portion  158  than the filter  154 . The liquid detection paper  210  has a property to change color when wetted with liquid. For example, as the liquid detection paper  210 , it is preferable to accept the cobalt chloride water whose color changes from blue to red when wetted with water, and a water finding test paper whose color is changed by water from white to blue. A casing  152  of the filter unit  150  is made of a transparent or translucent material so that the liquid detection paper can be recognized from outside. The transparent or translucent portion may constitute the entire casing  152 , or a portion thereof through which the liquid detection paper  210  can be viewed. The filter unit  150  configured as described above can detect the entrance of liquid into the casing  152  because the liquid detecting paper  210  changes color as a reaction to the entrance of liquid into the casing  152 . When liquid is detected, the paper is subjected to maintenance such as replacement or washing after use. It is also conceivable to use a filter  154  for gas/liquid separation changed color thereof when wetted with liquid.  
         [0085]     Furthermore, the liquid detection device is not limited to what is described above, but may be configured as shown in  FIG. 13 . The filter unit  150  shown in  FIG. 13  has two terminals  220  and  220  arranged close to each other in the space  150 A. These two terminals  220  and  220  are electrically connected to an alarm lamp  222  and a power source  224 . When water drips come into contact with the two terminals  220  and  220 , an electric current flows to light the alarm lamp  222 . Therefore, a liquid detection device configured above can also detect the presence of liquid.  
         [0086]     It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the invention is to cover all modifications, alternate constructions and equivalents falling within the spirit and scope of the invention as expressed in the appended claims.