Patent Publication Number: US-2020281450-A1

Title: Balloon endoscope and methods of manufacture and use thereof

Description:
REFERENCE TO RELATED APPLICATIONS 
     Reference is made to U.S. Provisional Patent Application Ser. No. 61/282,623, filed Mar. 9, 2010 and entitled “Endoscope with external fluid communication,” U.S. Provisional Patent Application Ser. No. 61/282,624, filed Mar. 9, 2010 and entitled “Balloon Endoscope with internal fluid communication,” U.S. Provisional Patent Application Ser. No. 61/344,690, filed Sep. 14, 2010 and entitled “Endoscope with External Gas Communication,” and U.S. Provisional Patent Application Ser. No. 61/457,236, filed Feb. 9, 2011 and entitled “Manufacturing Methods of Balloon Endoscope with External Fluid Communication,” the disclosures of which are hereby incorporated by reference and priorities of which are hereby claimed pursuant to 35 U.S.C. 33 CFR 1.38(a) (4) and (5)(i). 
     Reference is also made to applicant&#39;s copending PCT Application No. PCT/IL2005/000152, filed Feb. 7, 2005; PCT Application No. PCT/IL2005/000849, filed Aug. 8, 2005; PCT Application No. PCT/IL2007/000600, filed May 17, 2007; PCT Application No. PCT/IL2007/000832, filed Jul. 4, 2007; PCT Application No. PCT/IL2008/000687, filed May 20, 2008; PCT Application No. PCT/IL2009/000322, filed Mar. 23, 2009; PCT Application No. PCT/IL2009/000940, filed Oct. 1, 2009; and PCT Application No. PCT/IL2010/000425, filed May 30, 2010, the disclosures of which are hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to endoscopy generally and more particularly to balloon endoscopes. 
     BACKGROUND OF THE INVENTION 
     The following patent publications and commercially available products are believed to represent the current state of the art: 
     U.S. Pat. Nos. 3,837,347; 4,040,413; 4,148,307; 4,176,662; 4,195,637; 4,261,339; 4,453,545; 4,616,652; 4,676,228; 4,862,874; 4,917,088; 5,135,487; 5,259,366; 5,593,419; 6,007,482; 6,461,294; 6,585,639; 6,663,589; and 6,702,735; 
     U.S. patent application publication Nos. 2003/0244361; 2004/0102681; 2005/0124856; 2005/0125005; 2005/0133453; 2005/0137457; 2005/0165233; 2005/0165273; 2005/0171400; 2006/0111610; and 2006/0161044; 
     Japanese Patent Application publication No. JP2003-250896; 
     Published PCT Patent Applications WO 2005/074377; WO 2005/017854; WO 2007/135665; WO 2008/004228; WO 2008/142685; WO 2009/122395; WO 2010/046891; WO 2010/137025; and 
     Double Balloon Endoscope product, including EC-450BI5 colonoscope, TS-13101 overtube and BS-2 front balloon, which interface with balloon pump controller BP-20 and EPX-4400HD video system, all commercially available from Fujinon Inc., of 10 High Point Drive, Wayne, N.J., USA; and, 
     Single Balloon Endoscope product, including SIF-Q180 enteroscope, ST-SB1 overtube, which interface with balloon pump control OBCU and EVIS EXERA II system video system, ail commercially available from Olympus Inc., of 3500 Corporate Parkway Center Valley, Pa. 18034-0610, USA. 
     SUMMARY OF THE INVENTION 
     The present invention seeks to provide improved balloon endoscopes and method of manufacture thereof. 
     There is thus provided in accordance with a preferred embodiment of the present invention a balloon endoscope including an endoscope body having a selectably pressurizable interior volume, which generally fills the interior of the endoscope body and a selectably inflatable balloon located on an outer surface of the endoscope body and defining a balloon volume which communicates with the interior volume for selectable inflation of the balloon by selectable pressurization of the interior volume. 
     Preferably, at least one conduit extends through at least part of the selectably pressurizable interior volume. 
     In accordance with a preferred embodiment of the present invention at least one fluid conduit extends through at least part of the selectably pressurizable interior volume and is sealed therefrom. 
     Preferably, the at least one conduit includes an instrument channel. Additionally or alternatively, the endoscope body includes a leak test port communicating with the selectably pressurizable interior volume. Alternatively or additionally, the balloon endoscope also includes a fluid flow discriminator at a forward portion of the selectably pressurizable interior volume which prevents passage of liquid but permits passage of gas therethrough. 
     Preferably, the balloon endoscope also includes a balloon inflation/deflation control system communicating with the selectably pressurizable interior volume and with the selectably inflatable balloon and being operative to provide automatic leak testing of at least one of the selectably pressurizable interior volume and the selectably inflatable balloon. Additionally, the balloon inflation/deflation control system has at least two modes of operation including a positive pressure leak testing mode and a negative pressure leak testing mode. 
     In accordance with a preferred embodiment of the present invention the selectably inflatable balloon is retrofitted onto the endoscope body. Additionally or alternatively, the selectably inflatable balloon includes generally cylindrical rearward and forward ends having a fixed inner cross-sectional radius R 1 , a central cylindrical portion having a fixed inner cross-sectional radius R 2 , when inflated to a nominal pressure, slightly in excess of atmospheric pressure, and circularly symmetric tapered portions extending between the central cylindrical portion and each of the rearward and forward ends, whose inner radius changes from R 2  to R 1  where cos(Alpha) is approximately equal to r/R 2 , r is the inner radius of the balloon at a given location between the central cylindrical portion and one of the rearward and forward ends; and Alpha is the angle between a tangent to the balloon at the given location and a longitudinal axis of symmetry of the balloon. 
     Preferably, the selectably inflatable balloon is integrally formed as part of an outer sheath of the endoscope. In accordance with a preferred embodiment of the present invention the balloon endoscope also includes a bending section including a bending rubber sheath and the selectably inflatable balloon is located rearwardly of the bending rubber sheath. 
     Preferably, the selectably inflatable balloon is removably mounted onto the outer surface of the endoscope. In accordance with a preferred embodiment of the present invention the balloon endoscope also includes a bending section including a bending rubber sheath and wherein the selectably inflatable balloon overlies the bending rubber sheath. Additionally, the selectably inflatable balloon is generally coextensive with the bending rubber sheath. 
     There is also provided in accordance with another preferred embodiment of the present invention a balloon endoscope including an endoscope body having a leak test port and a selectably inflatable balloon associated with the endoscope body and defining a balloon volume which communicates with the leak test port. 
     Preferably, the endoscope body has a selectably pressurizable interior volume, which generally fills the interior of the endoscope body. Additionally or alternatively, the selectably inflatable balloon is located on an outer surface of the endoscope body. Alternatively or additionally, the balloon volume communicates with the interior volume for selectable inflation of the balloon by selectable pressurization of the interior volume via the leak test port. 
     In accordance with a preferred embodiment of the present invention at least one conduit extends through at least part of the selectably pressurizable interior volume. Preferably, at least one fluid conduit extends through at least part of the selectably pressurizable interior volume and is sealed therefrom. Additionally, the at least one conduit includes an instrument channel. 
     Preferably, the balloon endoscope also includes a fluid flow discriminator communicating with the balloon volume, which prevents passage of liquid but permits passage of gas therethrough. Additionally or alternatively, the balloon endoscope also includes a balloon inflation/deflation control system communicating with the balloon volume and being operative to provide automatic leak testing of the selectably inflatable balloon. Additionally, the balloon inflation/deflation control system has at least two modes of operation including a positive pressure leak testing mode and a negative pressure leak testing mode. 
     In accordance with a preferred embodiment of the present invention the selectably inflatable balloon is retrofitted onto the endoscope body. Additionally or alternatively, the selectably inflatable balloon includes generally cylindrical rearward and forward ends having a fixed inner cross-sectional radius R 1 , a central cylindrical portion having a fixed inner cross-sectional radius R 2 , when inflated to a nominal pressure, slightly in excess of atmospheric pressure, and circularly symmetric tapered portions extending between the central cylindrical portion and each of the rearward and forward ends, whose inner radius changes from R 2  to R 1  where cos(Alpha) is approximately equal to r/R 2 , r is the inner radius of the balloon at a given location between the central cylindrical portion and one of the rearward and forward ends and Alpha is the angle between a tangent to the balloon at the given location and a longitudinal axis of symmetry of the balloon. 
     Preferably, the selectably inflatable balloon is integrally formed as part of an outer sheath of the endoscope. In accordance with a preferred embodiment of the present invention the balloon endoscope also includes a bending section including a bending rubber sheath and the selectably inflatable balloon is located rearwardly of the bending rubber sheath. 
     In accordance with a preferred embodiment of the present invention the selectably inflatable balloon is removably mounted onto an outer surface of the endoscope. Additionally or alternatively, the balloon endoscope also includes a bending section including a bending rubber sheath and the selectably inflatable balloon overlies the bending rubber sheath. In accordance with a preferred embodiment of the present invention the selectably inflatable balloon is generally coextensive with the bending rubber sheath. 
     There is further provided in accordance with yet another preferred embodiment of the present invention an endoscope including an endoscope body having a forward portion and a rearward portion and a fluid passageway extending from the rearward portion to the forward portion and including a fluid flow discriminator at the forward portion which prevents passage of liquid but permits passage of gas. 
     Preferably, the fluid passageway includes an interior volume of the endoscope body, which generally fills the interior of the endoscope body. In accordance with a preferred embodiment of the present invention the fluid passageway includes a conduit extending through an interior volume of the endoscope body, which interior volume generally fills the interior of the endoscope body. 
     In accordance with a preferred embodiment of the present invention the fluid passageway includes a conduit. Preferably, the fluid passageway communicates with a leak test port of the endoscope. 
     In accordance with a preferred embodiment of the present invention the endoscope also includes a selectably inflatable balloon located on an outer surface of the endoscope body and defining a balloon volume which communicates with the fluid passageway for selectable inflation of the balloon. Additionally the selectably inflatable balloon is removably mounted onto the outer surface of the endoscope body. 
     In accordance with a preferred embodiment of the present invention the fluid flow discriminator includes a gas permeable, liquid impermeable filter. Additionally or alternatively, the endoscope also includes a balloon inflation/deflation control system communicating with the fluid passageway. 
     Preferably, the selectably inflatable balloon is retrofitted onto the endoscope body. In accordance with a preferred embodiment of the present invention the selectably inflatable balloon includes generally cylindrical rearward and forward ends having a fixed inner cross-sectional radius R 1 , a central cylindrical portion having a fixed inner cross-sectional radius R 2 , when inflated to a nominal pressure, slightly in excess of atmospheric pressure, and circularly symmetric tapered portions extending between the central cylindrical portion and each of the rearward and forward ends, whose inner radius changes from R 2  to R 1  where cos(Alpha) is approximately equal to r/R 2 , r is the inner radius of the balloon at a given location between the central cylindrical portion and one of the rearward and forward ends and Alpha is the angle between a tangent to the balloon at the given location and a longitudinal axis of symmetry of the balloon. 
     In accordance with a preferred embodiment of the present invention the selectably inflatable balloon is integrally formed as part of an outer sheath of the endoscope. Preferably, the balloon endoscope also includes a bending section including a bending rubber sheath and the selectably inflatable balloon is located rearwardly of the bending rubber sheath. 
     Preferably, the balloon endoscope also includes a bending section including a bending rubber sheath and wherein the selectably inflatable balloon overlies the bending rubber sheath. Additionally, the selectably inflatable balloon is generally coextensive with the bending rubber sheath. 
     There is yet further provided in accordance with still another preferred embodiment of the present invention a balloon endoscope including an endoscope body having a selectably pressurizable interior volume, which generally fills the interior of the endoscope body, a selectably inflatable balloon located on an outer surface of the endoscope body and a balloon inflation/deflation control system communicating with the selectably pressurizable interior volume and with the selectably inflatable balloon and being operative to provide automatic leak testing of at least one of the selectably pressurizable interior volume and the selectably inflatable balloon. 
     Preferably, the balloon inflation/deflation control system has at least two modes of operation including a positive pressure leak testing mode and a negative pressure leak testing mode. 
     In accordance with a preferred embodiment of the present invention the balloon inflation/deflation control system includes at least one of the following operational modules: an initialization module, operable prior to an endoscopy procedure, a real time leak monitoring balloon inflation module, operable during an endoscopy procedure and a real time leak monitoring balloon deflation module, operable during an endoscopy procedure. 
     More preferably, the balloon inflation/deflation control system includes at least two of the following operational modules: an initialization module, operable prior to an endoscopy procedure, a real time leak monitoring balloon inflation module, operable during an endoscopy procedure and a real time leak monitoring balloon deflation module, operable during an endoscopy procedure. Most preferably, the balloon inflation/deflation control system includes the following operational modules: an initialization module, operable prior to an endoscopy procedure, a real time leak monitoring balloon inflation module, operable during an endoscopy procedure and a real time leak monitoring balloon deflation module, operable during an endoscopy procedure. 
     In accordance with a preferred embodiment of the present invention the initialization module includes the following functionality: balloon endoscope pressurization producing balloon inflation, pressure leak test when the balloon endoscope is in a pressurized state and the balloon is surrounded by a balloon confining, gas permeable collar member, balloon endoscope depressurization producing balloon deflation, vacuum leak test when the balloon endoscope is in a pressurized state and provision of system go/no go indication. 
     Preferably, the real time leak monitoring balloon inflation module includes the following functionality: balloon endoscope pressurization producing balloon inflation, provision of complete balloon inflation indication, pressure leak test when the balloon endoscope is in a pressurized state within a body cavity and provision of leak indication. 
     In accordance with a preferred embodiment of the present invention the real time leak monitoring balloon deflation module includes the following functionality: balloon endoscope depressurization producing balloon deflation, provision of complete balloon deflation indication to the operator, pressure leak test when the balloon endoscope is in a depressurized state within a body cavity and provision of leak indication. 
     Preferably, the balloon endoscope also includes an endoscope tool balloon and the balloon inflation/deflation control system includes: an endoscope balloon inflation/deflation control system sub-system communicating with the selectably pressurizable interior volume and with the selectably inflatable balloon and being operative to provide automatic leak testing of at least one of the selectably pressurizable interior volume and the selectably inflatable balloon and an endoscope tool balloon inflation/deflation control system sub-system communicating with the endoscope tool balloon and being operative to provide automatic leak testing of the endoscope tool balloon. 
     In accordance with a preferred embodiment of the present invention the selectably inflatable balloon is retrofitted onto the endoscope body. 
     There is even further provided in accordance with another preferred embodiment of the present invention a method for balloon endoscopy including providing an endoscope including an endoscope body having a selectably pressurizable interior volume, which generally fills the interior of the endoscope body, and a selectably inflatable balloon and selectably inflating the selectably inflatable balloon by selectable pressurization of the interior volume. 
     Preferably, the selectably inflating includes selectably inflating the selectably inflatable balloon via a leak test port communicating with the selectably pressurizable interior volume. Additionally or alternatively, the selectably inflating includes enabling passage of gas but not liquid between the selectably pressurizable interior volume and the selectably inflatable balloon. 
     In accordance with a preferred embodiment of the present invention the selectably inflating includes providing automatic leak testing of at least one of the selectably pressurizable interior volume and the selectably inflatable balloon. 
     There is also provided in accordance with still another preferred embodiment of the present invention a method for balloon endoscopy including providing an endoscope including an endoscope body having a leak test port and a selectably inflatable balloon and selectably inflating the selectably inflatable balloon via the leak test port. 
     Preferably, the selectably inflating includes enabling passage of gas but not liquid between the selectably pressurizable interior volume and the the selectably inflatable balloon. Additionally or alternatively, the selectably inflating includes providing automatic leak testing of at least one of the selectably pressurizable interior volume and the selectably inflatable balloon. 
     There is further provided in accordance with yet another preferred embodiment of the present invention a method for balloon endoscopy including providing an endoscope having a forward portion and a rearward portion and a fluid passageway extending from the rearward portion to the forward portion and providing passage of gas but not liquid between the fluid passageway and a location outside the endoscope at the forward portion thereof. 
     In accordance with a preferred embodiment of the present invention the method for balloon endoscopy also includes selectably pressurizing the fluid passageway and providing gas communication between the fluid passageway and a balloon volume defined at the interior of a selectably inflatable balloon sealingly mounted over an outer surface of the forward portion of the endoscope. 
     There is still further provided in accordance with another preferred embodiment of the present invention a method for balloon endoscopy including providing an endoscope including an endoscope body having a selectably pressurizable interior volume and a selectably inflatable balloon located on an outer surface of the endoscope body and providing automatic leak testing of at least one of the selectably pressurizable interior volume and the selectably inflatable balloon. 
     There is even further provided in accordance with still another preferred embodiment of the present invention a method of manufacture of a balloon endoscope including providing an at least partially complete endoscope having a selectably pressurizable interior volume, providing at least one aperture in an outer sheath of the endoscope, the at least one aperture communicating with the selectably pressurizable interior volume and providing a selectably inflatable balloon over the outer sheath and in sealing engagement therewith, the balloon being arranged to have a balloon volume overlying the at least one aperture. 
     Preferably, the providing an at least partially complete endoscope includes providing an endoscope lacking at least part of the outer sheath and the providing at least one aperture includes forming an aperture in an outer sheath and thereafter mounting the outer sheath on the endoscope. 
     In accordance with a preferred embodiment of the present invention the method of manufacture of a balloon endoscope also includes associating a fluid flow discriminator with the at least one aperture. Additionally or alternatively, the providing an at least partially complete endoscope includes retrofitting the endoscope to remove at least part of the outer sheath thereof. 
     There is still further provided in accordance with yet another preferred embodiment of the present invention a method of manufacture of an endoscope including providing an at least partially complete endoscope and providing at least one aperture in an outer sheath of the endoscope and associating a fluid flow discriminator with the at least one aperture. 
     In accordance with a preferred embodiment of the present invention the method of manufacture of an endoscope also includes providing a selectably inflatable balloon over the outer sheath and in sealing engagement therewith, the balloon being arranged to have a balloon volume overlying the at least one aperture. Additionally or alternatively, the providing an at least partially complete endoscope includes providing an endoscope lacking at least part of the outer sheath and the providing at least one aperture includes forming an aperture in an outer sheath and thereafter mounting the outer sheath on the endoscope. 
     There is even further provided in accordance with still another preferred embodiment of the present invention a method of reprocessing a balloon endoscope including inflating a balloon of the balloon endoscope and reprocessing the balloon endoscope while the balloon is inflated. Preferably, the method of reprocessing the balloon endoscope also includes, prior to inflating the balloon of the balloon endoscope, placing a liquid spray permeable inflation limiting collar over the balloon. 
     There is yet further provided in accordance with another preferred embodiment of the present invention an inflatable/deflatable balloon suitable for use as part of a balloon endoscope or balloon catheter and including generally cylindrical rearward and forward ends having a fixed inner cross-sectional radius R 1 , a central cylindrical portion having a fixed inner cross-sectional radius R 2 , when inflated to a nominal pressure, slightly in excess of atmospheric pressure, and circularly symmetric tapered portions extending between the central cylindrical portion and each of the rearward and forward ends, whose inner radius changes from R 2  to R 1  where: cos(Alpha) is approximately equal to r/R 2 , r is the inner radius of the balloon at a given location between the central cylindrical portion and one of the rearward and forward ends and Alpha is the angle between a tangent to the balloon at the given location and a longitudinal axis of symmetry of the balloon. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be understood and appreciated from the following detailed description, taken in conjunction with the drawings in which: 
         FIGS. 1A &amp; 1B  illustrate a first embodiment of a balloon endoscope constructed and operative in accordance with the present invention; 
         FIGS. 2A &amp; 2B  illustrate a second embodiment of a balloon endoscope constructed and operative in accordance with the present invention; 
         FIGS. 3A &amp; 3B  illustrate a third embodiment of a balloon endoscope constructed and operative in accordance with the present invention; 
         FIG. 4  is a simplified illustration of an inflation/deflation control system preferably forming part of the balloon endoscopes of  FIGS. 1A-3B ; 
         FIGS. 5A-5J  are together a simplified pictorial flowchart which illustrates operation of a balloon endoscope in accordance with a preferred embodiment of the present invention; and 
         FIGS. 6A-6I  are simplified pictorial illustrations of a method of manufacture of a balloon endoscope in accordance with a preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The terms “endoscope” and “endoscopy” are used throughout in a manner somewhat broader than their customary meaning and refer to apparatus and methods which operate within body cavities, passageways and the like, such as, for example, the small intestine and the large intestine. Although these terms normally refer to visual inspection, as used herein they are not limited to applications which employ visual inspection and refer as well to apparatus, systems and methods which need not necessarily involve visual inspection. 
     The term “forward” refers to the remote end of an endoscope, accessory or tool furthest from the operator or to a direction facing such remote end. 
     The term “rearward” refers to the end portion of an endoscope, accessory or tool closest to the operator, typically outside an organ or body portion of interest or to a direction facing such end portion. 
     Reference is now made to  FIGS. 1A &amp; 1B , which illustrate a first embodiment of a balloon endoscope constructed and operative in accordance with the present invention. As seen in  FIGS. 1A &amp; 1B , an endoscope  100  is connected to an endoscope system (not shown). Other than as specifically described hereinbelow, the endoscope  100  may be a conventional endoscope such as an EC-3470LK video colonoscope or a VSB-3430K video enteroscope which are commercially available from Pentax Europe GmbH, 104 Julius-Vosseler St. 22527 Hamburg, Germany, and the endoscope system may be a conventional endoscope system such as a console including a EPK-1000 video processor and a SONY LMD-2140MD medical grade flat panel LCD monitor, all commercially available from Pentax Europe GmbH, 104 Julius-Vosseler St., 22527 Hamburg, Germany. 
     As distinct from a conventional endoscope, the endoscope  100  has an outer sheath  101  which is preferably provided with at least one balloon inflation/deflation aperture  102 , with which is associated a fluid flow discriminator such as a filter  104 , preferably a gas permeable, liquid impermeable filter, for example a Polytetrafluoroethylene filter, such as a Polytetrafluoroethylene filer sheath forming part of Hydrophobic Filter product P/N 28211, commercially available from Qosina Inc., 150-Q Executive Drive Edgewood, N.Y. 11717-8329 USA. Aperture  102  preferably communicates with an interior volume  106  of the endoscope  100 , which in conventional endoscopes is sealed from the exterior other than via a leak test port  108  at a rearward portion  110  of the endoscope. In accordance with a preferred embodiment of the present invention, interior volume  106  generally fills the interior of the endoscope  100 . 
     Alternatively, depending on the configuration of the endoscope, the leak test port  108  need not be located as illustrated in  FIGS. 1A &amp; 1B  but may be at a different location. 
     Alternatively one or more aperture  102  and filter  104  may be provided in the absence of a balloon for other applications such as insufflation of a body cavity, such as an intestine, by pressurizing the interior volume  106  of the endoscope via leak test port  108  and one or more aperture  102  and filter  104 . 
     Alternatively, as not shown, aperture  102  and filter  104  may communicate with a fluid flow passageway other than interior volume  106 , such as, for example, a fluid or other conduit, such as conventional dedicated balloon inflation/deflation channels, which are not known to be associated with filters at a forward portion thereof. 
     As in conventional endoscopes, endoscope  100  includes, forward of rearward portion  110 , an insertion tube portion  112  and, at a forward portion of endoscope  100 , a bending section  114 . In the embodiment of  FIGS. 1A &amp; 1B  aperture  102  and filter  104  are located in the bending section  114  of endoscope  100 . 
     Rearward portion  110  preferably includes, in addition to leak test port  108 , an instrument channel port  120 , which communicates with an instrument channel  122 , extending throughout the length of endoscope  100 . Rearward portion  110  preferably also includes conventional user interface elements, such as steering knobs  124  and  126  and other elements (not shown) and defines an interior volume, which forms part of interior volume  106  and communicates with the leak test port  108 . 
     Insertion tube portion  112  includes a reinforcement mesh  132  which serves to maintain the interior volume thereof against collapse during bending thereof so as to maintain communication therethrough between the interior volume of the rearward portion  110  and the interior volume of the bending section  114 . A tubular sealing sheath  134 , typically forming part of outer sheath  101 , seals the interior volume of insertion tube portion  112  from the exterior of the endoscope. In addition to the instrument channel  122 , an optical fiber bundle  136  also extends through the interior volume of the insertion tube portion  112 . Other conduits and other elements may also extend through this interior volume. 
     It is appreciated that interior volume  106  substantially fills the interior of endoscope  100  which is not occupied by conduits and other elements extending therethrough. Interior volume  106  is fluid sealed from the exterior of the endoscope  100  preferably other than via leak test port  108 . Accordingly, it is a particular feature of the present invention that interior volume  106  may be used, as not previously contemplated, for inflation and deflation of an endoscope balloon. 
     It is further appreciated that notwithstanding the fact that various conduits may extend through the interior volume  106 , their presence does not result in fluid communication between the interior volume  106  and the interior of any conduit extending therethrough. 
     Bending section  114  includes a selectably bendable reinforcement mesh  142  which is selectably bendable in response to operator manipulation of steering knobs  124  and  126 . The interior volume of bending section  114  is thus also protected against collapse during bending thereof so as to maintain communication therethrough with the interior volumes of the insertion tube portion  112  and of the rearward portion  110 . A tubular sealing bending rubber sheath  144 , typically forming part of outer sheath  101 , seals the interior volume of bending section  114  from the exterior of the endoscope. Bending rubber sheath  144  may be an off-the-shelf product, such as a silicone bending rubber sheath part number SPRBSS11, PVC bending rubber sheath part number SPRBSP11, or a Viton bending rubber sheath part number SPRBSV11, all commercially available from Endoscope Repair Inc. of 5201 Blue Lagoon Drive, No. 815 Miami, Fla. 33126 USA. Instrument channel  122 , optical fiber bundle  136  and optionally other elements extend through the interior volume of the bending section  114 . 
     In accordance with a preferred embodiment of the present invention, bending section  114  includes a rigid collar element  150 , preferably formed of metal, which underlies a forward end  151  of tubular sealing sheath  134  which is butted against a rearward end of sheath  144 . A rearward end  152  of an inflatable tubular balloon  154  is retained over rearward end of sheath  144  preferably by a wire  156  wound thereabout. The rearward end  152  of balloon  154  is preferably additionally sealed to sheath  144  by an adhesive  158 , such as a medical grade epoxy M31-CL, commercially available from Henkel Corporation, One Henkel Way Rocky Hill, Conn. 06067, USA. 
     Further in accordance with a preferred embodiment of the present invention, bending section  114  includes a rigid tip portion  170 , preferably formed of metal or plastic, a rearward portion  172  of which underlies a forward end  174  of sheath  144 . A forward end  176  of inflatable tubular balloon  154  is retained over forward end  174  of sheath  144  preferably by a wire  178  wound thereabout. The forward end  176  of balloon  154  is preferably additionally sealed to rigid tip portion  170  by an adhesive  180 , such as a medical grade epoxy M31-CL, commercially available from Henkel Corporation, One Henkel Way Rocky Hill, Conn. 06067, USA. 
     Filter  104  is preferably connected to sheath  144  underlying aperture  102  by any suitable technique, such as the use of adhesive, for example a Polychloroprene based Contact Cement commercially available from Elmer&#39;s Products Inc. of One Easton Oval Columbus, Ohio 43219, USA, may be used. It is appreciated that a gas communication path extends between the leak test port  108  via the interior volume  106 , filter  104  and aperture  102  to a balloon volume at the interior of inflatable/deflatable balloon  154 . 
     It is a particular feature of the present invention that inflatable/deflatable balloon  154  is inflated and/or deflated via the interior volume  106  of the balloon endoscope  100 . The available cross section of the interior volume  106  for inflation/deflation of the balloon  154  is typically 15-25 square millimeter, which is approximately 6-15 times greater than the cross section of balloon inflation channels employed in the prior art. This enables inflation and deflation of the balloon  154  to take place significantly faster than in prior art balloon endoscopes. 
     It is appreciated that the present invention enables retrofit of existing non-balloon endoscopes to become balloon endoscopes, without the complications and per treatment costs associated with conventional external balloon devices. These complications include limitations on bendability, torqueability and maneuverability as well as increased cross section and increased endoscope head resistance to advancement. Prior art balloon endoscopes have increased per treatment costs arising from difficulties in reprocessing, cleaning and disinfection thereof, resulting in single-use components, which are obviated in the operation of the present invention. 
     As seen in  FIGS. 1A &amp; 1B , the configuration of inflatable/deflatable balloon  154  is preferably as shown at A, characterized as follows: 
     Balloon  154  preferably has an overall length of 70-130 mm, more preferably 90-110 mm. Rearward and forward ends  152  and  176  respectively of balloon  154  are generally cylindrical and have a fixed inner cross-sectional radius R 1 , when forming part of balloon endoscope  100 . R 1  is preferably between 4 and 7 mm so as to tightly engage the adjacent portions of the endoscope. 
     A central cylindrical portion  182  of balloon  154  typically has a length of 25-70 mm and more preferably 30-55 mm and has a fixed inner cross-sectional radius R 2 , when inflated to a nominal pressure, such as 10-20 millibars in excess of atmospheric pressure. R 2  is preferably between 20 and 35 mm depending on the application. 
     Extending between the central cylindrical portion  182  and each of the rearward and forward ends  152  and  176  respectively are circularly symmetric tapered portions whose inner radius changes from R 2  to R 1  preferably in accordance with the following function: 
       cos(Alpha)≥ r/R 2
 
     where r is the inner radius of the balloon at a given location between the central cylindrical portion  182  and one of ends  152  and  176 ; and 
     Alpha is the angle between the tangent to the balloon at the given location and a longitudinal axis of symmetry of the balloon, here indicated by reference numeral  184 . 
     More preferably, cos(Alpha) is approximately equal to r/R 2 . 
     It is appreciated that the foregoing balloon configuration is applicable not only to balloon endoscopes but also to balloon catheters, with suitable adjustment being made to R 1  and R 2 . 
     Alternatively other balloon configurations may be employed, such as that shown at B. 
     As also seen in  FIGS. 1A &amp; 1B , the inflatable/deflatable balloon  154  may be fixed to the endoscope as described hereinabove and shown at A. Alternatively, the inflatable/deflatable balloon  154  may be removably attached to the endoscope as by stretchable rings  188 , as shown at B. 
     As additionally seen in  FIGS. 1A &amp; 1B , a single aperture  102  may be provided for gas communication between the interior of inflatable/deflatable balloon  154  and the interior volume  106  of endoscope  100  as described hereinabove and shown at A and B. Alternatively, plural apertures  102 , having associated therewith plural filters  104  may be provided for gas communication between the interior of inflatable/deflatable balloon  154  and the interior volume  106  of endoscope  100 , as shown as C. 
     As further seen in  FIGS. 1A &amp; 1B , the length of balloon  154  is preferably approximately similar to the length of the bending rubber sheath  144  and aligned therewith, as shown at A and B. This alignment allows rearward end  152  of balloon  154  to be mounted over the rigid collar element  150 , by the wires  156  and adhesive  158  as shown at A together with underlying rearward end of sheath  144 , or by removable ring  188  as shown at B, and allows forward end  176  of balloon  154  to be mounted over the rigid rearward portion  172  of rigid tip portion  170 , by wires  178  and adhesive  180  as shown at A together with underlying forward end  174  of sheath  144 , or by removable ring  188  as shown at B. 
     Alternatively, as shown at C in  FIGS. 1A &amp; 1B , the length of balloon  154  is shorter than the length of bending rubber sheath  144 , in which case end portions  152  and  176  of balloon  154  may be fixed to the bending rubber sheath  144  by any suitable known technique, such as by adhesive or by ultrasonic welding. 
     It is a particular feature of the present invention that an inflation/deflation control system  190  is coupled to the interior volume  106  of the endoscope  100  via leak test port  108 . 
     Reference is now made to  FIGS. 2A &amp; 2B , which illustrate a second embodiment of a balloon endoscope constructed and operative in accordance with the present invention. As seen in  FIGS. 2A &amp; 2B , an endoscope  200  is connected to an endoscope system (not shown). Other than as specifically described hereinbelow, the endoscope  200  may be a conventional endoscope such as an EC-3470LK video colonoscope or a VSB-3430K video enteroscope which are commercially available from Pentax Europe GmbH, 104 Julius-Vosseler St. 22527 Hamburg, Germany, and the endoscope system may be a conventional endoscope system such as a console including a EPK-1000 video processor and a SONY LMD-2140MD medical grade flat panel LCD monitor, all commercially available from Pentax Europe GmbH, 104 Julius-Vosseler St., 22527 Hamburg, Germany. 
     An interior volume  206  of the endoscope  200 , which preferably generally fills the interior of the endoscope  200 , is sealed from the exterior other than via a leak test port  208  at a rearward portion  210  of the endoscope  200 . 
     As in conventional endoscopes, endoscope  200  includes, forward of rearward portion  210 , an insertion tube portion  212  and, at a forward portion of endoscope  200 , a bending section  214 . 
     Rearward portion  210  preferably includes, in addition to leak test port  208 , an instrument channel port  220 , which communicates with an instrument channel  222 , extending throughout the length of endoscope  200 . Rearward portion  210  preferably also includes conventional user interface elements, such as steering knobs  224  and  226  and other elements (not shown) and defines an interior volume, which forms part of interior volume  206  and communicates with the leak test port  208 . 
     Insertion tube portion  212  includes a reinforcement mesh  232  which serves to maintain the interior volume thereof against collapse during bending thereof so as to maintain communication therethrough between the interior volume of the rearward portion and the interior volume of the bending section  214 . A tubular sealing sheath  234  seals the interior volume of insertion tube portion  212  from the exterior of the endoscope. In addition to the instrument channel  222 , an optical fiber bundle  236  also extends through the interior volume of the insertion tube portion  212 . Other conduits and elements may also extend through this interior volume. 
     Bending section  214  includes a selectably bendable reinforcement mesh  242  which is selectably bendable in response to operator manipulation of steering knobs  224  and  226 . The interior volume of bending section  214  is thus also protected against collapse during bending thereof so as to maintain communication therethrough with the interior volumes of the insertion tube portion  212  and of the rearward portion  210 . 
     A tubular sealing bending rubber sheath  244  seals the interior volume of bending section  214  from the exterior of the endoscope. Instrument channel  222 , an optical fiber bundle  236  and optionally other elements and conduits extend through the interior volume  246  of the bending section  214 . 
     As distinct from a conventional endoscope, tubular sealing bending rubber sheath  244  includes an integrally formed selectably inflatable/deflatable balloon portion  248 , the interior of which communicates with the interior volume  246  of the bending section  214 . Bending rubber sheath  244  with balloon portion  248  may be made of a generally stretchable material such as silicon, or a relatively non-stretchable material such as PVC, polyurethane, nylon or other polymeric material. 
     In accordance with a preferred embodiment of the present invention, bending section  214  includes a rigid collar element  250 , preferably formed of metal, which underlies a forward end  251  of tubular sealing sheath  234  which is butted against a rearward end of sheath  244 . 
     A fluid flow discriminator such as an in-line filter  252 , preferably a gas permeable, liquid impermeable filter, for example a Polytetrafluoroethylene filer, such as a Polytetrafluoroethylene filer sheath forming part of Hydrophobic Filter product P/N 28211, commercially available from Qosina Inc., 150-Q Executive Drive Edgewood, N.Y. 11717-8329 USA, is disposed within rigid collar element  250  and prevents liquid from passing between the interior volume  246  of the bending section  214  and the interior volume  206  of the remainder of the endoscope rearwardly thereof. It is appreciated that a gas communication path extends between the leak test port  208  via the interior volume  206 , filter  252  and interior volume  246  to the interior of inflatable/deflatable balloon portion  248 . 
     Alternatively, as not shown, the interior of integrally formed balloon portion  248  and filter  252  may communicate with a fluid flow passageway other than interior volume  206 , such as, for example, a fluid or other conduit, such as conventional dedicated balloon inflation/deflation channels, which are not known to be associated with filters at a forward portion thereof. 
     A rearward end  253  of tubular sealing bending rubber sheath  244  is retained over rigid collar element  250  preferably by a wire  256  wound thereabout. The rearward end  253  of tubular sealing bending rubber sheath  244  is preferably additionally sealed to sheath  234  by an adhesive  258 , such as a medical grade epoxy M31-CL, commercially available from Henkel Corporation, One Henkel Way Rocky Hill, Conn. 06067, USA. 
     Further in accordance with a preferred embodiment of the present invention, bending section  214  includes a rigid tip portion  270 , preferably formed of metal or plastic, a rearward portion  272  of which underlies a forward end  274  of sheath  244 . Forward end  274  of sheath  244  is retained over rearward portion  272  of rigid tip portion  270  preferably by a wire  278  wound thereabout. The forward end  274  of sheath  244  is preferably additionally sealed to rigid tip portion  270  by an adhesive  280 , such as a medical grade epoxy M31-CL, commercially available from Henkel Corporation, One Henkel Way Rocky Hill, Conn. 06067, USA. 
     It is a particular feature of the present invention that an inflation/deflation control system  290  is coupled to the interior volume  206  of the endoscope  200  via leak test port  208 . 
     Reference is now made to  FIGS. 3A &amp; 3B , which illustrate a third embodiment of a balloon endoscope constructed and operative in accordance with the present invention. As seen in  FIGS. 3A &amp; 3B , an endoscope  300  is connected to an endoscope system (not shown). Other than as specifically described hereinbelow, the endoscope  300  may be a conventional endoscope such as an EC-3470LK video colonoscope or a VSB-3430K video enteroscope which are commercially available from Pentax Europe GmbH, 104 Julius-Vosseler St. 22527 Hamburg, Germany, and the endoscope system may be a conventional endoscope system such as a console including a EPK-1000 video processor and a SONY LMD-2140MD medical grade flat panel LCD monitor, all commercially available from Pentax Europe GmbH, 104 Julius-Vosseler St., 22527 Hamburg, Germany. 
     As distinct from a conventional endoscope, the endoscope  300  preferably includes an outer sheath  301  which is preferably provided with at least one balloon inflation/deflation aperture  302 , with which is associated a fluid flow discriminator such as a filter  304 , preferably a gas permeable, liquid impermeable filter, for example a Polytetrafluoroethylene filer, such as a Polytetrafluoroethylene filer sheath forming part of Hydrophobic Filter product P/N 28211, commercially available from Qosina Inc., 150-Q Executive Drive Edgewood, N.Y. 11717-8329 USA. Aperture  302  communicates with an interior volume  306  of the endoscope, which in conventional endoscopes is sealed from the exterior other than via a leak test port  308  at a rearward portion  310  of the endoscope. 
     Alternatively, as not shown, aperture  302  and filter  304  may communicate with a fluid flow passageway other than interior volume  306 , such as, for example, a fluid or other conduit, such as conventional dedicated balloon inflation/deflation channels, which are not known to be associated with filters at a forward portion thereof. 
     In accordance with a preferred embodiment of the present invention, interior volume  306  generally fills the interior of the endoscope  300 . 
     As in conventional endoscopes, endoscope  300  includes, forward of rearward portion  310 , an insertion tube portion  312  and, at a forward portion of endoscope  300 , a bending section  314 . Aperture  302  and filter  304  are located in the insertion tube portion  312  of endoscope  300 . 
     Rearward portion  310  preferably includes, in addition to leak test port  308 , an instrument channel port  320 , which communicates with an instrument channel  322 , extending throughout the length of endoscope  300 . Rearward portion  310  preferably also includes conventional user interface elements, such as steering knobs  324  and  326  and other elements (not shown) and defines an interior volume, which forms part of interior volume  306  and communicates with the leak test port  308 . 
     Insertion tube portion  312  includes a reinforcement mesh  332  which serves to maintain the interior volume thereof against collapse during bending thereof so as to maintain communication therethrough between the interior volume of the rearward portion and the interior volume of the bending section  314 . A tubular sealing sheath  334 , typically forming part of outer sheath  301 , seals the interior volume of insertion tube portion  312  from the exterior of the endoscope. In addition to the instrument channel  322 , an optical fiber bundle  336  also extends through the interior volume of the insertion tube portion  312 . Other conduits and elements may also extend through this interior volume. 
     Bending section  314  includes a selectably bendable reinforcement mesh  342  which is selectably bendable in response to operator manipulation of steering knobs  324  and  326 . The interior volume of bending section  314  is thus also protected against collapse during bending thereof so as to maintain communication therethrough with the interior volumes of the insertion tube portion  312  and of the rearward portion  310 . A tubular sealing bending rubber sheath  344 , typically forming part of outer sheath  301 , seals the interior volume of bending section  314  from the exterior of the endoscope. Bending rubber sheath  144  may be an off-the-shelf product, such as a silicone bending rubber sheath part number SPRBSS11, PVC bending rubber sheath part number SPRBSP11, or a Viton bending rubber sheath part number SPRBSV11, all commercially available from Endoscope Repair Inc. of 5201 Blue Lagoon Drive, No. 815 Miami, Fla. 33126 USA. 
     Instrument channel  322 , an optical fiber bundle  336  and optionally other conduits and elements extend through the interior volume of the bending section  314 . 
     In accordance with a preferred embodiment of the present invention, bending section  314  includes a rigid collar element  350 , preferably formed of metal, which underlies a forward end  351  of tubular sealing sheath  334  which is butted against a rearward end of sheath  344 . 
     An inflatable tubular balloon  354  is sealingly mounted over tubular sealing sheath  334  of insertion tube portion  312 , overlying aperture  302  and filter  304  as by any suitable technique such as ultrasonic welding or an adhesive  358 . 
     Further in accordance with a preferred embodiment of the present invention, bending section  314  includes a rigid tip portion  370 , preferably formed of metal or plastic, a rearward portion  372  of which underlies a forward end  374  of sheath  344 . 
     Filter  304  is preferably connected to sheath  334  underlying aperture  302  by any suitable technique, such as the use of adhesive. It is appreciated that a gas communication path extends between the leak test port  308  via the interior volume  306 , filter  304  and aperture  302  to the interior of inflatable/deflatable balloon  354 . 
     It is a particular feature of the present invention that an inflation/deflation control system  376  is coupled to the interior volume  306  of the endoscope  300  via leak test port  308 . 
     Reference is now made to  FIG. 4 , which is a simplified illustration of an inflation/deflation control system  380  useful in the balloon endoscopes of  FIGS. 1A-3B . 
     As seen in  FIG. 4 , the inflation/deflation control system  380  preferably includes a pressure pump  382  and a vacuum pump  384 , which are preferably at least partially controlled by a computerized control sub-system  386  having associated therewith a user interface  388 , preferably including buttons and visually sensible indicators. Preferably pressure pump  382  and vacuum pump  384  are each connectable to a leak test port of a balloon endoscope, such as that shown in  FIGS. 1A-3B  (not shown in  FIG. 4 ) via a manifold  390  and a flow meter  391 . A pressure sensor  392  and a pressure valve  394  are preferably connected in series between the pressure pump  382  and manifold  390 . A vacuum sensor  395  and a vacuum valve  396  are preferably connected in series between the vacuum pump  384  and manifold  390 . 
     The computerized control sub-system  386  preferably includes initialization module  397 , preferably operative prior to insertion of the balloon endoscope into a body cavity; and a real time leak monitoring balloon inflation module  398  and a real time leak monitoring balloon deflation module  399 , both preferably operative when the balloon endoscope is inserted at a desired location in a body cavity. 
     The initialization module  397 , which is preferably automatically operated upon turning on the inflation/deflation control system  380  preferably has the following functionality:
         balloon endoscope pressurization producing balloon inflation;   pressure leak test when balloon endoscope is in a pressurized state and the balloon is surrounded by a balloon confining, gas permeable collar member;   balloon endoscope depressurization producing balloon deflation;   vacuum leak test when balloon endoscope is in a depressurized state; and   provision of system go/no go indication to the operator.       

     The real time leak monitoring balloon inflation module  398 , which is preferably actuated by the operator following insertion of the balloon endoscope to a desired location within a body cavity, preferably has the following functionality:
         balloon endoscope pressurization producing balloon inflation;   provision of complete balloon inflation indication to the operator;   periodical positive pressure leak test when balloon endoscope is in a pressurized state within a body cavity such as the intestine; and   provision of leak indication to the operator.       

     The real time leak monitoring balloon deflation module  399 , which is preferably actuated by the operator following insertion of the balloon endoscope to a desired location within a body cavity, preferably has the following functionality:
         balloon endoscope depressurization producing balloon deflation;   provision of complete balloon deflation indication to the operator;   periodical negative pressure leak test when balloon endoscope is in a depressurized state within a body cavity such as the intestine; and   provision of leak indication to the operator.       

     It is a particular feature of the present invention that the real time leak monitoring balloon inflation module  398  is responsive to an output from the flow meter  391  in order to distinguish between a sensed pressure drop at the interior of the endoscope which results from a change in the effective volume of the intestine during a procedure and a sensed pressure drop at the interior of the endoscope which results from a leak. By monitoring the total flow to the interior of the balloon endoscope and noting the total volume of the inflated balloon and the interior of the endoscope, a sensed pressure drop combined with an indication of fluid flow which exceeds this total volume indicates the presence of a leak. 
     It is appreciated that the functionality of modules  398  and  399  has utility even in the absence of a balloon, where the interior of the endoscope is sealed from the exterior thereof during operation thereof, such as in otherwise conventional endoscopes wherein automatic real time leak testing of the interior volume of the endoscope during operation of the endoscope is highly desirable. 
     Reference is now made to  FIGS. 5A-5J , which are together a simplified pictorial flowchart which illustrates operation of a balloon endoscope in accordance with a preferred embodiment of the present invention. 
     As seen in  FIG. 5A , there is provided a balloon endoscope constructed and operative in accordance with a preferred embodiment of the invention, such as any one of the embodiments of an endoscope described hereinabove, and in particular for the illustrated example of  FIGS. 5A-5J , the endoscope shown at A in  FIGS. 1A &amp; 1B . For the sake of convenience and conciseness, the reference numerals used in conjunction with  FIGS. 1A &amp; 1B  are employed throughout the description of  FIGS. 5A-5J . 
     Preferably prior to beginning endoscopy treatments each day, a manual leak test is performed on the endoscope  100  using a conventional endoscope leak tester  402 , such as a model PLT-5500, commercially available from Instrument Specialists Inc., 32390 IH-10 West, Boerne, Tex. 78006-9214, USA, and a balloon confining, gas permeable collar member  404  which allows gas to escape from a leaky balloon but limits expansion thereof. 
     As seen in  FIG. 5B , the leak tester  402  is operatively connected to the leak test port  108  of the balloon endoscope  100  and the collar  404  is placed over the balloon  154  of the balloon endoscope  100 . Using the leak tester  402 , positive pressure is applied via the test port  108  and the interior volume  106  of the balloon endoscope  100  in order to pressurize and inflate the balloon  154 . The pressure within the interior volume  106  is visually monitored to detect any pressure decrease over time which would indicate a rupture in the balloon  154  or elsewhere in the endoscope  100  which would permit fluid communication between the exterior of the endoscope  100  and its interior volume  106 . 
     Upon successful completion of the leak test, the leak tester  402  and the collar  404  are detached from the endoscope  100 , which is ready for clinical use. 
     Reference is now made to  FIG. 5C , which illustrates a novel further leak test performed in a clinical setting just prior to insertion of the endoscope  100  into a body cavity. As indicated in  FIG. 5C , collar  404  is placed over balloon  154  and inflation/deflation control system  190  is coupled to the interior volume  106  of the endoscope  100  via leak test port  108 . The operator initiates an automatic Clinical Integrity Test Protocol (CITP) preferably by actuating a CITP button  406 . 
     The Clinical Integrity Test Protocol preferably includes, inter alia, (a) a leak test during balloon inflation and (b) a subsequent leak test during application of vacuum to the balloon. Preferably, upon successful completion of the Clinical Integrity Test Protocol, a visual indication is automatically provided to the operator, such as by illumination of an indicator light  408 . 
     Immediately following successful completion of the CITP protocol, as shown in  FIG. 5D , the endoscope  100  may be inserted, with balloon  154  in a deflated state, into a body cavity, such as a patient&#39;s intestine and advanced to a location  410  therein at which it is desired to inflate balloon  154 . 
     While balloon  154  is still in a deflated state, module  399  is automatically operative to provide periodic leak testing of balloon  154  and the interior volume  106  of endoscope  100 , while the endoscope is in a body cavity. 
     The balloon  154  is then inflated at location  410 , as shown in  FIG. 5E  by supplying pressurized gas via the leak test port  108  and the interior volume  106  of the endoscope  100  to the interior of the balloon  154 . While balloon  154  is in an inflated state, module  398  is automatically operative to provide periodic leak testing of balloon  154  and the interior volume  106  of endoscope  100 , while the endoscope is in a body cavity. 
     Inflation of balloon  154  is preferably operative to anchor the balloon endoscope and thereby to spatially stabilize the endoscope  100  in the intestine and allow various diagnostic and/or therapeutic procedures to be carried out using conventional endoscope tools and techniques as indicated, for example in  FIG. 5F . Examples of diagnostic and/or therapeutic procedures which are advantageously carried out using the balloon endoscope  100  include removal of polyps, as shown in  FIG. 5F , performing biopsies, dilating strictures, suturing, stapling and clipping. Following completion of the diagnostic and/or therapeutic procedures, the endoscope tools may be removed and the balloon  154  may be deflated to allow advancement or retraction of the endoscope. 
     A two-balloon technique, such as that illustrated in  FIGS. 5G &amp; 5H  may be employed in order to facilitate advancement of the balloon endoscope in the intestine. Conventional two-balloon endoscope advancement is known, and described in details for example in applicant&#39;s copending PCT Application No. PCT/IL2005/000152, filed Feb. 7, 2005; PCT Application No. PCT/IL2005/000849, filed Aug. 8, 2005; PCT Application No. PCT/IL2007/000600, filed May 17, 2007; and in US patent application publication No. US 2005/0171400.  FIGS. 5G &amp; 5H  show the provision of a second inflation/deflation control system  420 , which may be identical in structure and function to inflation/deflation control system  380  ( FIG. 4 ) and is also useful with the balloon endoscopes of  FIGS. 1A-3B . 
     Second inflation/deflation control system  420  preferably includes an initialization module (not shown), similar or identical to initialization module  397  of inflation/deflation control system  380 , preferably operative prior to insertion of the balloon endoscope into a body cavity. Second inflation/deflation control system  420  preferably also includes a real time leak monitoring balloon inflation module  428 , similar or identical to real time leak monitoring balloon inflation module  398  of inflation/deflation control system  380  and a real time leak monitoring balloon deflation module  429 , similar or identical to real time leak monitoring balloon deflation module  399 , of inflation/deflation control system  380 . 
     Second inflation/deflation control system  420  preferably communicates with an endoscope tool balloon  440  mounted on a flexible tube  442  of an endoscope tool  444 . In two-balloon endoscope advancement, endoscope tool balloon  440  is operated preferably using the protocol described above with reference to  FIGS. 4 and 5C . More specifically, a novel further leak test is performed in a clinical setting just prior to insertion of the endoscope tool  444  into instrument channel  122  of endoscope  100 . 
     The operator initiates an automatic Clinical Integrity Test Protocol (CITP) preferably by actuating a CITP button  456 . 
     The Clinical Integrity Test Protocol preferably includes, inter alia, (a) a leak test during balloon inflation and (b) a subsequent leak test during application of vacuum to the balloon. Preferably, upon successful completion of the Clinical Integrity Test Protocol, a visual indication is automatically provided to the operator, such as by illumination of an indicator light  458 . 
     Immediately following successful completion of the CITP protocol, the endoscope tool  444  may be inserted through the instrument channel  122  in a deflated state and thereafter inflated forward of the endoscope  100 , as shown in  FIG. 5G . 
     While balloon  440  is still in a deflated state, module  429  is automatically operative to provide periodic leak testing of balloon  440  while the endoscope is in a body cavity. 
     While balloon  440  is an inflated state, as shown in  FIG. 5G , module  428  is automatically operative to provide periodic leak testing of balloon  440 , while the endoscope  100  and the balloon  440  are in a body cavity. 
     It is appreciated that while balloon  154  and endoscope  100  are in the body cavity, periodic leak testing thereof continues in accordance with the protocols established by modules  398  and  399 , described above. 
     Stages of two-balloon advancement of the endoscope  100  are illustrated in  FIGS. 5G and 5H , employing balloons  154  and  440 . Thereafter, additional two-balloon advancement steps may take place. Following each advancement step, balloon  440  may be deflated as shown in  FIG. 5H . While balloon  440  is still in a deflated state, module  429  is automatically operative to provide periodic leak testing of balloon  440 . Once tool  444  is no longer required, it may be removed via the instrument channel  122 , when balloon  440  is in a deflated state. 
       FIG. 5I  shows removal of the balloon endoscope  100  from the patient body cavity, with balloon  154  in a deflated state. While balloon  154  is still in a deflated state, module  399  is automatically operative to provide periodic leak testing of balloon  154  and the interior volume  106  of endoscope  100 , while the endoscope is in a body cavity. 
       FIG. 5J  illustrates reprocessing, including cleaning of the balloon endoscope  100  following use thereof. Manual cleaning of balloon  154  while inflated is shown at A and machine cleaning of the balloon  154  within a liquid spray permeable inflation limiting collar  460  is shown at B. In both cases, the balloon  154  is preferably inflated via leak test port  108  and then sealed in an inflated state for cleaning, as by a stopcock  462 . 
     Reference is now made to  FIGS. 6A-6J , which are simplified pictorial illustrations of a method of manufacture of a balloon endoscope in accordance with a preferred embodiment of the present invention. 
     A conventional non-balloon endoscope  500  such as an EC-3470LK video colonoscope or a VSB-3430K video enteroscope which are commercially available from Pentax Europe GmbH, 104 Julius-Vosseler St. 22527 Hamburg, Germany, may be provided. 
     Alternatively, an endoscope of a different manufacturer may be employed. In such a case, a leak test port may be located at various locations or may not be provided. In the former case, if the location of the leak test port is not suitable, the existing leak test port may be sealed and a new leak test port formed, as by a retrofit procedure, at a suitable location in communication with the interior volume of the endoscope. In the latter case, a leak test port may be provided in communication with the interior volume of the endoscope, as by a retrofit procedure. 
     The endoscope  500  may be retrofitted as a balloon endoscope by initially removing a bending rubber sheath  502  therefrom, as seen in  FIGS. 6A &amp; 6B . This is preferably accomplished by first removing the epoxy-covered wound retaining wires  504  and  506  which attach the sheath  502  to the remainder of the endoscope  500 . As shown in a simplified manner in  FIG. 6A , this may be achieved by first grinding down the epoxy and then cutting the wire using a scalpel. 
     Thereafter, as shown in a simplified manner in  FIG. 6B , the bending rubber sheath  502  may then be slit using the scalpel and an underlying protective plate inserted between the bending rubber sheath  502  and the protective mesh  508  of the endoscope  500 . 
     The result of the steps shown in  FIGS. 6A and 6B  is an endoscope having an exposed bending section  510 . Alternatively, an endoscope may be initially constructed to have an exposed bending section  510 . 
     In a separate manufacturing sequence, an aperture  518  is formed in a conventional bending rubber sheath  520 , such as a silicone bending rubber sheath part number SPRBSS11, PVC bending rubber sheath part number SPRBSP11, or a Viton bending rubber sheath part number SPRBSV11, all commercially available from Endoscope Repair Inc. of 5201 Blue Lagoon Drive, No. 815 Miami, Fla. 33126 USA, by any suitable technique, such as punching. A filter element  522  is preferably adhered by an adhesive  524 , such as a Polychloroprene based Contact Cement commercially available from Elmer&#39;s Products Inc. of One Easton Oval Columbus, Ohio 43219, USA, to the interior of the bending rubber sheath  520  underlying aperture  518 , such as by the use of an inserter  526 . A removable fluid sealing patch  528  is preferably placed over the aperture  518  on the outside of the bending rubber sheath  520 . 
     The resulting apertured, filter-equipped and sealed bending rubber sheath assembly  530  is preferably inserted into a bending rubber sheath placement tool  532 . Tool  532  preferably includes a cylinder  533  which is shorter than sheath assembly  530 . The axial ends  534  and  536  of sheath assembly  530  are preferably bent over onto the corresponding axial ends  538  and  540  of tool  532 , as shown in  FIG. 6D . 
     A vacuum port  542  communicates with the interior of the cylinder  533  of tool  532 . A vacuum is applied between the interior of tool  532  and the exterior of sheath assembly  530  via vacuum port  542 , thereby producing radial stretching of sheath assembly  530  and resulting axial expansion thereof, as shown in  FIG. 6D . 
     Turning now to  FIG. 6E , it is seen that the endoscope having an exposed bending section  510 , ( FIG. 6B ) is inserted into the tool  532  holding the sheath assembly  530  under vacuum in a radially expanded state ( FIG. 6D ), such that the rearward end  538  of tool  532  overlies a rigid collar element  550  of endoscope  500  and the forward end  540  of tool  532  overlies a rearward portion  552  of a rigid tip portion  554  of endoscope  500  as seen at A. 
     The vacuum is then released as shown at B, allowing part of the bending rubber assembly  530  to collapse onto the reinforcement mesh  508 . As shown at C, the ends  534  and  536  of the bending rubber assembly  530  are then rolled off corresponding ends  538  and  540  of tool  532  and onto rigid collar element  550  and onto rearward portion  552  of rigid tip portion  554  of endoscope  500 , respectively. As shown in  FIG. 6F , the resulting partially retrofitted endoscope  560  has rearwardly facing edge  564  of bending rubber assembly  530  in butting relationship with a corresponding forwardly facing edge  566  of a tubular sealing sheath  568  of endoscope  560  as seen at A and a forwardly facing edge  570  of bending rubber assembly  530  in butting relationship with a corresponding rearwardly facing edge  572  of rigid tip portion  554  of endoscope  560 , as shown at B. 
     As further seen in  FIG. 6F , the tool  532  is slipped off of the endoscope  500  and the patch  528  is removed. 
     Turning to  FIG. 6G , it is seen that a balloon, preferably a pre-shaped balloon  580  such as balloon  154  as described hereinabove, is slipped over the bending rubber assembly  530  of endoscope  500  such that the respective axial ends  582  and  584  of balloon  580  are aligned with respective ends  534  and  536  of the bending rubber assembly  530  and more particularly preferably such that a rearwardly facing edge  588  of balloon  580  overlies rearwardly facing edge  564  of bending rubber assembly  530  and a forwardly facing edge  590  of balloon  580  overlies forwardly facing edge  570  of bending rubber assembly  530 . 
     As seen in  FIG. 6H , wires  592  and  594  are tightly wound about respective ends  582  and  584  of balloon  580 . Thereafter, as seen in  FIG. 6I , the wound wires are preferably encased in epoxy  596  together with the respective butting edges  564  &amp;  566  and  570  &amp;  572  and corresponding ends  534  and  536  of bending rubber assembly  530 . 
     The steps shown particularly in  FIGS. 6H and 6I  provide fluid sealing between the interior volume of the balloon  580  and the exterior thereof and also provides fluid sealing between respective ends  534  and  536  of the bending rubber assembly  530  and rigid collar element  550  and rearward portion  552  of rigid tip portion  554  of endoscope  500 . The provision of epoxy  596  additionally provides fluid sealing between the respective butting edges  564  &amp;  566  and  570  &amp;  572 . 
     The result of the manufacturing steps shown in  FIGS. 6A-6I  is a balloon endoscope constructed and operative in accordance with a preferred embodiment of the present invention. A particular feature of the present invention in both the retrofit and non-retrofit balloon endoscopes is use of the interior volume of the endoscope for balloon inflation and deflation. It is also a particular feature of the present invention that retrofit of a conventional endoscope as a balloon endoscope requires only modification of the bending section of the endoscope. 
     It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described herein above. Rather the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove as well as variations and modifications which would occur to persons skilled in the art upon reading the specifications and which are not in the prior art.