Abstract:
Provided is a balloon access device having a cap coupleable to an endoscope and a balloon for sealing with the cap when expanded. The balloon access device allows a physician to both separate collapsed tissue and visualize the path of the endoscope without administering insufflation gas to the collapsed area of a patient.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/471,957 filed Apr. 5, 2011 and International Application No. PCT/US2012/032248 filed Apr. 5, 2012, which are hereby incorporated herein by reference. 
     
    
     FIELD OF INVENTION 
       [0002]    The present apparatus embodied relates, in general, to medical devices and in particular, to access balloons used in combination with endoscopes. 
       BACKGROUND 
       [0003]    Endoscopes are well-known in the art and are flexible devices that are inserted into a natural body orifice such as the mouth or anus to provide visual and surgical access to portions of the upper and lower Gastro Intestinal (GI) tract. Endoscope accessible portions of the lower GI tract extend from the anus to the small intestine, and during this journey, the flexible endoscope must traverse a torturous convoluted path through the anus, the rectum, and through the large intestine to the ileocecal opening of the small intestine. The torturous path includes an “S” shaped passage through the rectosigmoid junction and the sigmoid colon, and around several larger than right angled bends of the splenic flexure and hepatic flexure. Additionally, in small bowel enteroscopy, an endoscope must traverse a large torturous convoluted path having multiple “S” shaped passages. 
         [0004]    Before insertion of the endoscope, the patient is given drugs to purge fecal matter from the lower GI tract. Once emptied, the tubular walls of the large intestine can flatten or collapse together into a flattened tubular configuration. The collapsed intestines may inhibit passage of the flat face of the distal end of the endoscope, and the collapsed tissue can inhibit visualization by pressing against or near to a camera mounted within the flat face. To enhance the passage of the endoscope through the collapsed lower GI tract and to improve visualization, insufflation gas is routinely pumped into the patient&#39;s lower GI tract to expand and distend the collapsed tubular tissues. The expanded walls may improve visualization and reduce tissue contact with the flat face of the endoscope as it is pushed farther and farther into the insufflated lower GI tract. The distal portion of the endoscope is steerable, and the insufflated tissue can provide room for the surgeon to visually steer the endoscope through the path ahead. 
         [0005]    The administration of insufflation gas to the lower GI tract can induce abdominal discomfort, and this has led to the common practice of using professional anesthesia providers to induce anesthesia to “knock-out” the patient. Additionally, insufflation gas may cause lengthening of anatomy and spontaneous perforation. Post surgical recovery times are provided to allow the patient to purge insufflation gas and to awaken from the anesthesia. CO2 gas control systems, CO2 tanks, and CO2 gas heaters have found their way into the operating room to provide CO2 as a insufflation gas. The CO2 gas is more readily absorbed through the patient&#39;s intestinal wall to reduce the post operative recovery time. 
       SUMMARY OF INVENTION 
       [0006]    The present invention provides a balloon access device having a cap coupleable to an endoscope and a balloon for sealing along with the cap when expanded. The balloon access device allows a physician to both separate collapsed tissue and visualize the path of the endoscope without administering insufflation gas to the collapsed area of a patient. 
         [0007]    In one embodiment, the balloon access device includes a balloon expandable from a deflated shape to an inflated shape, the balloon having a proximal end and a distal end, wherein a dome portion is formed on the distal end of the balloon, and a cap having a proximal end configured to be coupled to a distal end of an endoscope and a distal end for sealing with the proximal end of the balloon when the balloon is expanded. 
         [0008]    In another embodiment, the  1  the inflated shape includes a non-pressurized shape and a fully inflated shape. 
         [0009]    In still another embodiment, the proximal end of the balloon includes a proximal collar configured to couple to a distal end of a catheter and a sealing surface configured to seal with the cap. 
         [0010]    In yet another embodiment, the cap includes an endoscope receptacle extending into the cap through the proximal end of the cap for receiving the distal end of the endoscope. 
         [0011]    In a further embodiment, the cap includes a stop that engages a front face of the endoscope when the endoscope is received within the cap, and wherein an opening is provided through the stop to distally expose at least one of a light, opening, optics or operative channel on the front face of the endoscope. 
         [0012]    In another embodiment, the cap includes a balloon sealing portion proximate the distal end of the cap, the balloon sealing portion including a circular groove that retains and seals with a circular rib of the balloon. 
         [0013]    In still another embodiment, the cap includes an outwardly flaring balloon sealing portion that is flexible outwardly relative to a body of the cap to create a seal with the balloon. 
         [0014]    In yet another embodiment, the outwardly flaring balloon sealing portion prevents the balloon from being unseated from the cap. 
         [0015]    In a further embodiment, the cap includes a rib on an interior portion of the cap, and wherein the sealing surface of the balloon nests and seals with a receptacle of a balloon sealing portion and the rib. 
         [0016]    In another embodiment, the dome portion is hemispherical or ellipsoidal in shape. 
         [0017]    In still another embodiment, the balloon is non-concentrically disposed relative to the endoscope. 
         [0018]    In yet another embodiment, the balloon includes a distally located guide tip on a distal portion of the dome portion for guiding an operator in parting and spreading non-insufflated gastrointestinal tissue during operation. 
         [0019]    In a further embodiment, the balloon is a transparent hollow balloon. 
         [0020]    In another embodiment, the balloon access device includes a lock mechanism for securing a catheter relative to the endoscope to maintain a sealing contact between the balloon and the cap. 
         [0021]    In still another embodiment, the lock mechanism includes a releasably lockable clamp mechanism that contacts and grips the catheter. 
         [0022]    In yet another embodiment, the balloon access device includes a lock mechanism including a balloon insertion tube for receiving the balloon when the balloon is in the deflated state, the tube having a length greater than a y-portion of an operative channel within the endoscope to guide the balloon into and beyond the y-portion, and a clamp for securing a catheter relative to the endoscope to maintain a sealing contact between the balloon and the cap. 
         [0023]    In a further embodiment, the balloon access device includes a balloon insertion tube for receiving the balloon when the balloon is in the deflated state, the balloon insertion tube having a length greater than a y-portion of an operative channel within the endoscope to guide the balloon into and beyond the y-portion. 
         [0024]    In another embodiment, the balloon access device is in combination with a catheter, wherein the proximal end of the balloon is coupled to a distal end of the catheter. 
         [0025]    In still another embodiment, the balloon access device is in combination with an endoscope, wherein the proximal end of the cap is coupled to the distal end of the endoscope. 
         [0026]    In yet another embodiment, the cap is integral with the endoscope. 
         [0027]    According to another aspect of the invention, a balloon access device for use with an endoscope is provided. The device includes a balloon expandable from a deflated shape to an inflated shape, the balloon having a proximal end and a distal end, wherein a dome portion is formed on the distal end of the balloon, a cap having a proximal end configured to be coupled to a distal end of an endoscope and a distal end for sealing with the proximal end of the balloon when the balloon is passed through the cap and expanded to the inflated shape, and a balloon insertion tube for receiving the balloon when the balloon is in the deflated state, the balloon insertion tube having a length greater than a y-portion of an operative channel within the endoscope to guide the balloon into and beyond the y-portion. 
         [0028]    According to still another aspect of the invention, a method of creating a seal between a balloon and a cap is provided, the balloon having a proximal end having a sealing surface and proximal collar coupled to a distal end of a catheter, and the cap having a proximal end coupled to a distal end of an endoscope, the method including advancing the catheter and balloon through an operative channel of the endoscope until the balloon is positioned distal the distal end of the cap, expanding the balloon from a deflated shape to at least a partially inflated shape, and moving the balloon proximally towards the cap so that the sealing surface ( 66 ) abuts a distal end of the cap to create a seal between the cap and the balloon. 
         [0029]    According to yet another aspect of the invention, a method of performing a gastrointestinal procedure on a patient having gastrointestinal tissue in a non-insufflated state using an endoscope and balloon access device installed upon the endoscope is provided, the balloon access device including a cap coupled to a distal end of the endoscope and an at least partially inflated balloon coupled to a distal end of a catheter received in an operative channel of the endoscope, the method including advance the endoscope through the gastrointestinal tissue, guiding the endoscope using a camera on a distal end of the endoscope and a guide tip on a distal end of the balloon, and spreading the tissue using a body of the balloon and the guide tip, wherein the balloon is transparent so that an operator can view the tissue through the balloon using the camera and the operator can center the guide tip in a gastrointestinal tract. 
         [0030]    In one embodiment, the method includes retracting the endoscope from the gastrointestinal tissue, wherein during the retracting a balloon sealing portion of the cap flattens a luminal fold in the tissue. 
         [0031]    The foregoing and other features of the invention are hereinafter described in greater detail with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]      FIG. 1  is an isometric view of an embodiment of a transparent balloon access device deployed on an endoscope. 
           [0033]      FIG. 2  is an isometric view of the balloon access device with the transparent balloon shown in a normal unexpanded dome shape. 
           [0034]      FIG. 3  is an isometric exploded view of the balloon access device 
           [0035]      FIG. 4  is an isometric view of the balloon access device with the balloon shown collapsed by drawing a vacuum prior to being inserted into an adjacent balloon insertion tube. 
           [0036]      FIG. 5  is an isometric view of the balloon access device with a balloon seal cap placed on a distal end of the scope and with a dashed line illustrating a path where the balloon access device can enter an open instrument channel which exits within the attached balloon seal cap. 
           [0037]      FIG. 6  is a side section view of the flexible shaft of the endoscope with an un-inflated balloon being pushed longitudinally along an instrument passage of the endoscope. 
           [0038]      FIG. 7  is a side view showing the balloon after emerging from a distal end of the endoscope. 
           [0039]      FIG. 8  is a side view showing the balloon inflated after emerging from a distal end of the endoscope. 
           [0040]      FIG. 9  shows an exploded cross sectional view of an embodiment of the balloon and balloon seal cap. 
           [0041]      FIG. 10  shows an exploded cross sectional view of an embodiment of the balloon and balloon seal cap. 
           [0042]      FIG. 11  shows an exploded cross sectional view of an embodiment of the balloon and balloon seal cap. 
           [0043]      FIG. 12  shows an exploded cross sectional view of an embodiment of the balloon and balloon seal cap. 
           [0044]      FIG. 13  shows the balloon of  FIG. 12  in a normal un-inflated shape wherein the inner air pressure is the same as the outside atmospheric pressure. 
           [0045]      FIG. 14  shows the balloon of  FIG. 12  in an inflated shape where about 2.5 ml of air have been placed into the balloon and cannula. 
           [0046]      FIG. 15  shows the balloon of  FIG. 12  in an inflated shape where about 3.5 ml of air have been placed into the balloon and cannula. 
           [0047]      FIG. 16  shows the balloon of  FIG. 12  in an inflated shape where about 5 ml of air have been placed into the balloon and cannula. 
           [0048]      FIG. 17  is a side cross sectional view of the balloon access device installed upon an endoscope as the balloon access device spreads tissue to burrow through non-insufflated and collapsed luminal tissue. 
           [0049]      FIG. 18  is an enlarged side cross sectional view of the balloon access device of  FIG. 17  showing spreading forces on the collapsed luminal tissue. 
           [0050]      FIG. 19  is a view through the camera lens of the endoscope showing a guide tip of the balloon moved to a centered position in a collapsed tissue lumen opening to ensure passage of the balloon and endoscope down a center of the lumen. 
           [0051]      FIG. 20  is a cross sectional view of a blow molding dies that is configured to make the balloon of  FIG. 12 . 
           [0052]      FIG. 21  is an isometric view of a clamp mechanism to clamp or lock the tensioned cannula relative to the endoscope to maintain a sealing contact between balloon and seal cap. 
           [0053]      FIG. 22  is an alternate a clamp mechanism. 
           [0054]      FIG. 23  is a front view of a distal end of an endoscope. 
       
    
    
     DETAILED DESCRIPTION 
       [0055]    The following description of certain examples of the medical apparatus should not be used to limit the scope of the medical apparatus. Other examples, features, aspects, embodiments, and advantages of the medical apparatus will become apparent to those skilled in the art from the following description, which is by way of illustration, one of the best modes contemplated for carrying out the medical apparatus. As will be realized, the medical apparatus is capable of other different and obvious aspects, all without departing from the spirit of the medical apparatus. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive. 
         [0056]    It should be appreciated that any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. 
         [0057]      FIG. 1  is an isometric view of one embodiment of a balloon access device  30  installed upon an endoscope  100 . The balloon access device  30  is configured to fit within an operative channel  102  of the endoscope  100  when undeployed, and to deploy a transparent hollow balloon  60  across a distal face  104  of the endoscope  100 . The balloon  60  is transparent so that scope optics can view GI tissue there through, and balloon  60  can be dome shaped on at least a distal end. A distally located guide tip  62  is supported solely on a distal end of the dome shape by a membrane wall  65  of the balloon  60 . The configuration of the deployed guide tip  62  and balloon  60  on the endoscope  100  is such that non-insufflated GI tissue can be parted and spread with the tip  62  and the balloon  60  in response to pushing with the endoscope  100 . The balloon access device  30  and endoscope  100  as configured can rapidly burrow along a non-insufflated and at least partially pinched GI tract such as the non-insufflated lower GI tract, or can pass through an expanded or insufflated portion of the GI tract. As will be described in detail later, the deployed transparent guide tip  62  can be visually aimed at a center of the collapsed lumen of the non-insufflated GI tract by articulating a distal end  106  of the endoscope  100 . When the guide tip  62  is aimed, pushing the endoscope  100  initiates the spreading and parting of the collapsed tissue walls with the balloon access device  30 , thereby enabling passage of the endoscope  100  along a center of the non-insufflated lumen of the GI tract. 
         [0058]    As shown in  FIG. 1 , the balloon access device  30  is shown inserted into an operative channel  102  of the endoscope  100  and comprises a proximal handle portion  50  extending from a proximal opening of the instrument channel  102 . A biopsy valve  108  is provided on the proximal opening of the instrument channel  102  and a hollow cannula  70  extends from the proximal handle portion  50 , through the biopsy valve  108 , and into the instrument channel  102 . A distal end of the cannula  70  is secured to a proximal end of the transparent balloon  60  shown extending across a distally located front face  104  of the endoscope  100 . 
         [0059]    A balloon seal cap  40  of the balloon access device  30  is removably secured to the distal end  106  of the endoscope  100  and forms a fluid tight seal with at least one surface on a proximal end of the balloon  60 . Alternatively, it will be appreciated that the cap  40  may be integral with the endoscope. The seal cap  40  may be any suitable shape, such as cylindrically shaped. The sealing interaction of the seal cap  40  with the endoscope  100 , and the balloon  60  with the seal cap  40 , can create a sealed volume across the front face  104  of the endoscope  100  to prevent the egress of unwanted fluids across the optical lens  105  of an endoscope camera located on the front face  104  (see  FIG. 17 ). Additionally, once the seal is formed, the balloon  60  can be further secured to the seal cap  40  by applying a vacuum to the instrument channel  102  to draw the balloon  60  into further engagement with the seal cap  40 . Alternately, a vacuum port (not shown) in the endoscope  100  can be used to draw the balloon  100  against the front face  104  of the endoscope. The balloon device  30  can be rapidly deployed and inflated into place on the endoscope  100  for advancement, and rapidly deflated and withdrawn from the instrument channel  102  of the endoscope  100  for the insertion and deployment of another surgical instrument from the instrument channel  102  into the lower GI tract. An example of such another surgical instrument can be, but is not limited thereto, a snare or tissue biopsy device to retrieve a tissue sample from a suspect site. 
         [0060]      FIG. 2  shows an isometric view of the balloon access device  30 . The handle or proximal handle portion  50  includes a hollow passage  72  that extends longitudinally through the handle portion  50 , through the hollow cannula  70 , and operatively connects to an inner volume of the balloon  60 . Handle portion  50  includes a proximal luer lock  52  to removably engage hollow passage  72  with compressed gas and/or vacuum lines and or fluid lines, a valve  54  to control the flow of gas and vacuum to the distal balloon  60 , a grip  56 , and orientation wings  58 . Hollow cannula  70  can be configured to have sufficient length to work with an endoscope  100  as described above, or long enough to work with a variety of endoscopes  100  with differing lengths. 
         [0061]    In  FIGS. 2 and 3 , the transparent balloon  60  is shown in the normal unpressurized or “as manufactured” shape wherein the hollow balloon  60  can have a distal dome  64  and at least one sealing surface  66  on a proximal side. The balloon  60  is configured to be symmetrical and concentric about a longitudinal axis of the balloon  60  and a longitudinal axis of the cannula  70 , and the distal dome  64  can be hemispherical or elliptical in shape about the axis. A proximal collar  68  securely seals the balloon  60  to the catheter  70  via an attachment method such as but not limited thereto, by an adhesive or a shrink fit as described later. Proximal collar  68  can be cylindrical and can include a conical or curved portion for engaging with or sealing with the instrument passage  102  of endoscope  100 . The guide tip  62  can be a separate piece that can be secured to the dome of the balloon  60  in the exemplary manner. As best shown in  FIG. 3 , the guide tip  62  has a rounded distal tip and a stepped proximal post  69  that can be adhesively secured into a distal collar  67  formed from the balloon membrane  65 . Alternately, the guide tip could be a rounded bump formed from the balloon membrane  65 , or an injection of sealing material into the distal collar  67  such as a gob of silicone placed inside the distal collar  67 . The guide tip  62  can be transparent for visualization therethrough, or can be opaque or translucent. As shown, guide tip  62  is supported by only the balloon membrane  65  which can provide some freedom of motion of the tip  62  relative to the endoscope  100 . This freedom of motion can beneficial when navigating through collapsed tissue A hollow balloon insertion tube  80  is shown distal to the guide tip  62  may be provided to receive and store the balloon  60  and tip  62  within when the balloon is deflated by drawing a vacuum prior to being inserted into an adjacent balloon insertion tube  80  , and tube  80  can have a length sufficient to guide the balloon  60  and tip  62  into and beyond a “Y” portion of the operative channel  102  within the endoscope  100 , A deflated balloon  60  is shown in  FIG. 4  just prior to insertion within a hollow of the balloon insertion tube  80 . Before insertion, balloon  60  may have one or more deflation folds of the balloon  60  wrapped or twisted about a longitudinal axis of the balloon (not shown) to create a more compact and organized deflated balloon  60 . 
         [0062]      FIG. 5  shows the access device  30  ready for installation onto the endoscope  100 . In this view, the cylindrical seal cap  40  is positioned for placement onto the distal end  106  of the endoscope  100 . The balloon  60  is fully deflated as shown in  FIG. 4 , and resides within the balloon insertion tube  80 . A dashed line is provided to show how the balloon insertion tube  80  of the access device  30  can be inserted into the proximal opening of the instrument channel  102  of endoscope  100 , and if a biopsy valve  108  is provided, through the biopsy valve  108 . The balloon insertion tube  80  can be configured to feed the balloon  60  directly into the instrument channel  102  through the balloon insertion tube  108  with the guide tip  62  leading the collapsed balloon. Balloon insertion tube  80  can be the length as shown, or can be longer to guide the collapsed balloon past a “Y” within instrument channel  102  Balloon insertion tube  80  can be constructed from a slick or lubricious plastic such as PTFE, or can be lubricated to reduce egress of the collapsed balloon  60  into or out of the tube  80 .  FIG. 1  shows how the balloon insertion tube  80  can be retracted proximally around the cannula  72  to a position adjacent to the handle portion  50  after the full insertion of the access device  30  into the instrument channel  102 . 
         [0063]      FIG. 6  shows the fully deflated balloon as it is being pushed down channel  102  of the endoscope  100  prior to emergence of the balloon  60  from the distal face  40  of the endoscope  100 . The guide tip  62  can be configured with a tip diameter that is close to the inner diameter of the instrument channel  102  of the endoscope  100 , and an appropriate length so that the tip  62  will not cock and jam within the instrument channel  102  of the scope  100 . The tip of the guide tip  62  can be any shape that is conducive to steering the guide tip along the instrument channel  102  such as the rounded tip  62  shown, or any other guiding shape such as but not limited to a cone. 
         [0064]      FIG. 7  shows the balloon  60  after emerging from the distal end  106  of the endoscope  100 . Once the balloon  60  is extended from the endoscope  60  and beyond the seal cap  40 , atmospheric air may be induced through the hollow passage  72  to allow the balloon  60  to expand into the non-pressurized shape as shown. Once the balloon  60  is fully inflated with a fluid, such as air, to an operating pressure or volume, the balloon  60  is pulled proximally in the direction of the arrow to engage the balloon  60  with the seal tip  40 . This pulling of the balloon  60  to seal against the seal tip  40  can be accomplished by pulling on the catheter  70  or the handle portion  50  outside of the patient. If required, the balloon  60  is free to pivot somewhat about the attachment point to the cannula  70  to center itself in the seal cap  40 . 
         [0065]      FIG. 8  shows the fully inflated balloon  60  pulled against the seal cap  40  at the distal end  106  of the endoscope  100 . In this view, it can be seen that the inflation of the balloon  60  has changed the at least one proximal sealing surface  66  into a rounded dome that has maintained a fluid-tight seal with the seal cap  40 . The rounding of the at least one proximal sealing surface  66  has moved the distal dome  64  distally, and the distal dome  64  has expanded both in diameter and longitudinally as shown. The inflation of the balloon  60  can be accomplished prior to insertion of the endoscope  100  into the patient, or after insertion of the endoscope  100  into the natural orifice such as the anus of the patient. 
         [0066]      FIGS. 9 through 12  shows exploded cross sectional views of alternate exemplary embodiments of the balloon  60 , and balloon seal cap  40  of the present apparatus. The guide tip  62  is also depicted. The exemplary and previously described embodiment of balloon  60  and seal collar  90  is best shown in  FIGS. 2, and 3 , and is shown in cross section in  FIG. 11 . The reader is advised to note that the balloon access device  30  is not limited to the previously described embodiment of  FIG. 11 , nor to the alternate embodiments of  FIGS. 9-10 and 12 , nor to any of the materials or manufacturing techniques described. Since many of the embodiments of the balloons and seal caps have features that perform the same function, like numbers are identified with sub-identifiers and are meant to correspond to like features on alternate embodiments. For example, a balloon  60  in one embodiment may become a balloon  60   a  in another alternate embodiment. If differences in functions exist between like numbers such as sealing surfaces  66  and  66   a,  the description associated with the number and sub-identifier will prevail for that embodiment. All embodiments described below have a balloon  60 ,  60   a.    60   b,    60   c  and a seal cap  40 ,  40   a,    40   b,    40   c.    
         [0067]    The embodiment of  FIG. 11  comprises the hollow balloon  60 , the balloon seal cap  40  and the guide tip  62 . This embodiment uses a ring-in-groove seal between the balloon and seal cap  40 . The balloon  60  comprises the previously described distal dome  64 , the membrane  65 , and the at least one sealing surface  66 . With this embodiment of the balloon  60 , the at least one sealing surface  66  of the balloon comprises two distinct portions. The first portion comprises a circular rib  61  that rings the longitudinal axis of the balloon  60  and is configured to engage with and seal with the circular groove  41  in the seal cap  40 . The second portion of the at least one sealing surface  66  is a dish shaped portion that extends substantially radially inwardly between the largest diameter of distal dome  64  to the circular rib portion. The dish shaped portion can be configured to seal against at least a distalmost surface  48  of the cap  40 . The distal collar  67  of balloon  60  extends distally from the dome  64  and is configured to seal with the distal tip  62 . The proximal collar  68  extends proximally from the at least one sealing surface  66  and is configured to seal with the hollow cannula  70  (see  FIGS. 2 and 3 ). 
         [0068]    The balloon seal cap  40  of  FIG. 11  comprises a hollow cylinder having an endoscope receptacle  42  extending into a proximal end of the seal cap  40  to receive and seal with the distal end  106  of the endoscope  100 . A circular rib  45  can be provided at a distal end of the endoscope receptacle  42  to act as a stop that engages the front face  104  of the endoscope  100  once the scope  100  is fully received within the seal cap  40 . An opening  46  is provided through the rib  45  to distally expose the optics, lights, and openings on the endoscope front face  104 . A balloon sealing portion  44  extends distally from the rib  45  and includes the previously described circular groove  41  to retain and seal with the circular rib  61  of the balloon  60 . The distalmost surface  48  of the balloon sealing portion  44  can seal with the balloon  60 . As shown, the receptacle  42 , the opening  46 , and the balloon sealing portion  44  comprise the open hollow of the cylindrical seal cap  40 . 
         [0069]    The embodiment of  FIG. 9  comprises a balloon  60   a  and a seal cap  40   a  and is configured to provide a ball-in-socket type of sealing. The balloon  60   a  has a substantially curved at least one sealing surface  66   a  that nests within and seals with an outwardly flaring cuplike balloon sealing portion  44   a  of the seal cap  40   a . Seal cap  40   a  can be configured to flare outward to provide a larger support for the balloon  60   a  and can exceed the diameter of the endoscope  100 . Seal cap  40   a  is a hollow cylinder that further comprises an endoscope sealing receptacle  42   a,  circular rib  45   a,  opening  46   a , as well as the previously described balloon sealing portion  44   a . Balloon  60   a  includes a distal dome  64   a , a membrane  65 a, a distal collar  67   a , and a proximal collar  68   a . Cuplike balloon sealing portion  44   a  of the seal cap  40   a  can also be used to flatten luminal folds, for example to discern pathologies behind the luminal folds. 
         [0070]    The embodiment of  FIG. 10  comprises a balloon  60   b  and a seal cap  40   b  and uses a peg- in-hole arrangement for sealing. In this embodiment, the balloon  60   b  is sized to have about the same radial diameter as the distal end  106  of the endoscope and the balloon  60   b  nests and seals with a receptacle of a cylindrical balloon sealing portion  44   a . Mushroom shaped balloon  60   a  comprises a distal dome  64  with at least one sealing surface  66   a  that is substantially flat and circular. Balloon  60   b  is configured to fit snugly in the cylindrical balloon sealing portion  44   a  and to seal the at least one sealing surface  66   a  against a rib  45   b . Cylindrically shaped cap  40   b  further comprises an endoscope sealing receptacle  42   b , and an opening  46   b  extending through rib  45   b . Balloon  60   b  includes a distal dome  64   b , a membrane  65   b , a distal collar  67   b,  and a proximal collar  68   b.    
         [0071]    The embodiment of  FIG. 12  comprises a balloon  60   c  and seal cap  40   c  that is configured to provide a flat-to flat seal as the balloon  60   c  is pulled against a distalmost surface  48   c  of seal cap  40   c . As the inflating balloon  60   c  changes shape from the mushroom shape to a rounded elliptical ball shape, the seal can move to a beveled portion of a distal balloon sealing portion  44   c . Balloon  60   c  may be substantially mushroom shaped with a substantially flat at least one sealing surface  66   c  adjacent to a dome  64   c . Unlike the embodiment of  FIG. 10 , the balloon  60   c  is larger than an outer diameter of a seal cap  40   c  and overhangs the seal cap  40   c . Cylindrically shaped cap  40   c  further comprises an endoscope sealing receptacle  42   c,  circular rib  45   c , and opening  46   c . Balloon  60   a  further comprises a distal dome  64   a , a membrane  65   a,  a distal collar  67   a , and a proximal collar  68   a.    
         [0072]    The balloons  60 ,  60   a ,  60   b , and  60   c  are transparent and can be constructed from a substantially rigid balloon material or an elastomeric material. Substantially rigid cannot expand greatly beyond the normal “as made” shape when inflated and many such materials are well known in the art for use as expansion balloons for cardiac stent deployment products. Elastomeric balloons are expandable, and can comprise material such as, for example, some grades or durometers of elastomers such as polyurethane, latex, natural rubbers, silicones and the like. 
         [0073]    The seal caps  40 ,  40   a ,  40   b , arid  40   c  can comprise a substantially rigid material such as a thermoform plastic, a thermoset plastic, or a metal. With rigid embodiments of the caps, it is the deformation of the balloon  60 ,  60   a ,  60   b , and  60   c  against the rigid cap that creates the seal. In yet another embodiment, the seal caps  40 ,  40   a ,  40   b , and  40   c  can comprise an elastomeric material such as but not limited to a polyurethane, a polyethylene, silicone, rubber and the like. As such, the elastomeric properties of this embodiment can have sufficient rigidity to generally support the balloon against normal surgical operating forces, yet provide atraumatic characteristics, should substantial resistance be encountered. Rigidity of the elastomeric material could be altered by changing a durometer of the material during manufacturing. 
         [0074]    Alternately, the distal balloon sealing portion  44 ,  44   a ,  44   b ,  44   c  of the caps  40 ,  40   a ,  40   b , and  40   c  could be rigid or elastomeric and can further comprise one or more deformable gasket materials to create a seal such as but not limited to: an elastomeric lip seal, an o-ring, an over-molded elastomer, or a foam seal (not shown). Such seals can seal with the balloon  40 , the endoscope  100  or both. 
         [0075]    The distal guide tip  62  can be used with any balloon embodiments such as  60 ,  60   a ,  60   b , and  60   c . The distal guide tip  62  can include the stepped proximal post  69  which is configured to fit within the distal collar  67 ,  67   a ,  67   b,  or  67   c  to create a smooth exterior when mated with the balloon  60 ,  60   a ,  60   b , or  60   c  (see at least  FIGS. 1&amp;2 ). The guide tip  66  and cannula 70  can be adhered to the balloon  60 ,  60   a ,  60   b , or  60   c  with adhesives such as but not limited to polyurethanes or cyanoacrylates. Or, alternate fastening techniques can be used with distal guide tip  62  and cannula  70  such as but not limited to heat staking, ultrasonically welding, or laser welding. Whereas these fastening techniques are described for the attachment of the distal guide tip  62 , they can be used for all other embodiments of the apparatus such as elements of the handle portion  50  or attachment of the proximal collar  68  to the cannula  80 . 
         [0076]      FIGS. 13-16  are side views that detail the inflation of the distal portion of the balloon access device  30  on the endoscope  30 . The mushroom shaped balloon  60   c  and cap  40   c  are the embodiments shown in cross section in  FIG. 12 . For this inflation description, only the embodiment of  FIG. 12  will be described, and the description is based on physical measurements of an actual balloon  60   c  and cap  40   c  as the balloon  60   c  is inflated. 
         [0077]      FIG. 13  shows balloon  60   c  in a normal un-inflated normal shape wherein the inner air pressure is the same as the outside atmospheric pressure and the balloon  60   c  has assumed the “as manufactured” mushroom shape. As shown, the normal shape of balloon  60   c  is substantially mushroom shaped, and comprises the distal dome  64   c  attached to the proximal at least one sealing surface  66   c . The at least one sealing surface  66   c  is substantially flat and has been pulled back (via catheter  70 ) to seal against a ring of contact with the ring shaped distalrnost surface  48   c  of the seal cap  40 . With atmospheric pressure within balloon  60   c , and the valve  54  of the handle portion  50  closed, the balloon  62  is very flaccid and the guide tip  62  is substantially supported by only the membrane  65   c . Pushing the guide tip  62  towards the cannula  70  creates a large indention crater with the tip  62  standing proud within as the tip  62  is completely pushed into the dome  64   c . Measurements of the balloon  60   c  of  FIG. 13  show an outer dimension D 1  of about 18 mm at the widest diameter, and the sum of io longitudinal lengths A 1  and B 1  equal about 11 mm. The balloon  60   c  and cannula  70  of the actual test balloon  60   c  required about 2-2.1 ml of air to arrive at the flaccid shape of  FIG. 13 . 
         [0078]      FIG. 14  is another side view of the access device  30  on the endoscope  30  where about 2.5 ml of air have been placed into the balloon  60   c  and cannula  70 . At this air volume, the distal dome  64   c  maintained substantially the same shape, but the at least one sealing surface  66   c  domed slightly and pushed the distal dome  64   c  and guide tip  62  in the distal direction. This increased the sum of longitudinal lengths A 1  and A 2  to about 11.7 mm without an appreciable change in D 2 . It is visually seen that the majority of the 0.7 mm balloon longitudinal length change occurred in the doming of the at least one sealing surface  66   c  which increased dimension B 2 . Pushing on the distal guide tip  62  so that it is embedded within the balloon created a slightly smaller dish shaped indent with the guide tip  62  standing proud in the indent. The increased volume of fill also increased the resistance to movement of the tip  62 . The balloon  60   c  did not appear to move longitudinally from pushing on the guide tip  62  but expanded radially when filled with 2.5 ml of air. 
         [0079]      FIG. 15  is another side view of the access device  30  on the endoscope  30  where about 3.5 ml of air have been placed into the balloon  60   c  and cannula  70 . Once again, the distal dome  64   c  maintained substantially the same shape and the at least one sealing surface  66   c  continued to move towards a dome shape. The longitudinal length (sum of A 1  and B 1 ) increased to about 12.2 mm with the majority of the 0.5 mm additional length increase coming from additional doming of the at least one sealing surface  66   c . The dimension D 2  increased slightly to 18.73 mm. When the guide tip  62  was pushed distally into the balloon  60   c , the distal guide tip  62  had substantial resistance. Pushing on the distal guide tip  62  so that it is embedded within the balloon created a noticeably smaller dish shaped indent with the guide tip  62  standing proud in the indent. As the guide tip  62  was embedded into the balloon  60   c , the balloon  60   c  also moved distally as some of the distal movement of the guide tip  62  was transferred to the balloon  60   c . Visually, it appears that there is about the same amount of distal longitudinal movement of the balloon  60   c  as there is distal embedding of the guide tip  62 . The distal movement of the balloon  60   c  is primarily in the at least one sealing surface  66   c .    
         [0080]      FIG. 16  is another side view of the access device  30  on the endoscope  100  where about  5  ml of air have been placed into the balloon  60   c  and cannula  70 . The diameter D 1  reduced back to the original 18 mm diameter and the longitudinal length (sum of A 1  and B 1 ) increased to about 14.75 mm. Once again, the majority of the additional length increase (2.55 mm) appears to be coming from additional doming of the at least one sealing surface  66   c . There was some additional rounding of the distal dome  64   c  which may account for some of the reduction in overall diameter D 1  and some of the length change. With respect to pushing distally on the guide tip  62  with 5 ml of air, the guide tip  62  has substantial resistance and the combination of balloon geometry (mushroom shape), fill volume (ml) balloon membrane  65   c  thickness and material durometer have combined to provide an unexpected shift in load transfer that seems to prevent the guide tip  62  from creating much of a dish indent in the balloon. With this fill volume, a substantial portion of the movement of the guide tip  62  towards the cannula  70  comes from a longitudinal compression of the balloon  60   c  to a different elliptical shape, and not from dishing the guide tip  62  into the balloon  60 . This effect may be advantageous to tunneling through non-insufflated tissue lumens to maintain the distalmost positioning of the guide tip  62  during airless burrowing of the access device  30  and the endoscope  100 . It is the distalmost position of the guide tip  62  which can enable the guide tip  62  to initiate separation of the collapsed luminal tissue. Once the initial separation occurs, the collapsed tissue separation may then be transferred to the outer surface of the balloon  60   c  as the access device  30  and endoscope  100  advances along the GI tract. 
         [0081]      FIGS. 17 and 18  are side cross sectional views of the balloon access device  30  installed upon an endoscope  100  as it burrows through non-insuf Rated luminal tissue of the GI tract.  FIG. 18  is an enlarged view of a portion of the cross sectional view of  FIG. 17 . As shown, the luminal tissue has collapsed, and the balloon access device  30  is providing both a visualization pocket and a tissue separator for the operator of the endoscope  100  so that the endoscope  100  can be easily advanced farther into the patient. An arrow is provided to indicate the direction of movement of the balloon access device  30  and endoscope  100 . In this cross section, the collapsed luminal tissue  200  is partially spread by the balloon access device  30  and endoscope  100  as it burrows towards a bend in the tissue  200 . The endoscope  100  is shown in cross section and has the instrument channel  102  and front face  104  shown. Front face  104  of the scope  100  further comprises a lens  105  that views tissue through the transparent balloon  60 . A viewing angle of the lens  105  is shown as dashed lines extending from the lens  105  (see  FIG. 18 ). To prevent reduction of the viewing angle, the cap  40  may protrude above the front face  104  of the scope between about 0.5 mm to about  6 mm. Alternately, the cap  40  may protrude above the front face  104  of the scope between about  1 mm to about 3 mm. If desired, the vacuum in the endoscope  100  can be used to draw the balloon  100  against the front face  104  and the lens  105  of the endoscope  100 . The hollow catheter  70  extends longitudinally along the instrument channel  102  and is attached to the balloon  60  which is inflated (via the catheter  70 ) an amount that substantially restricts the embedding of the guide tip  62  into the balloon as described previously. The cap  40  is sealed against the endoscope and the balloon  60  is sealed within the cap  40  to seal the front face  104  of the endoscope  100  from fluids, mucous, and residual natural materials normally found within the luminal structure. As shown, ring  61  of the balloon is embedded in the groove  41  in the seal cap  40  to create a seal. 
         [0082]      FIG. 18  is an enlarged side cross sectional view of  FIG. 17 . In this view, the spreading of the collapsed opening  204  of the tissue  200  can be seen through the transparent balloon  60 . The lens  105  of the endoscope can be seen with dashed lines indicating a field of view through the balloon access device  30 . Arrows show how a spreading force F 1  is applied from the guide tip  62  onto the tissue  200 . The guide force F 1  is perpendicular or normal to the point of contact on the tissue. A second spreading force F 2  is exerted on the tissue by the inflated balloon  60 . Once again, the spreading force F 2  is perpendicular or normal to the point of contact of the membrane  65  of the balloon  60  on the tissue. 
         [0083]      FIG. 19  is a view through the lens  105  of the camera of the endoscope  100  looking at collapsed tissue through the transparent balloon  60  and guide tip  62 . In this view, the surgeon has steered the guide tip  62  of the balloon  60  to a centered position of the collapsed tissue opening  204  of the tissue  200 . Since the tissue guide  200  is transparent, tissue  200  can be seen therethrough. Once the guide tip  62  of the balloon  60  is centered, the surgeon is confident that the balloon access device  30  and endoscope  100  are aimed at the center of the collapsed lumen, and that the balloon access device  30  and endoscope  100  can now be pushed down a center of the lumen such as the large intestine. During testing of the device in actual tissue, several of the medical professional operators were surprised at the depth of penetration of the balloon access device  30  equipped endoscope  100  in such a short time. 
         [0084]      FIG. 20  is a cross sectional view of a blow molding dies that is configured to make the balloon of  FIG. 12 . As shown, the blow molding die  210  has a piece of expandable polyethylene tubing  220  placed along a longitudinal axis of the balloon shape of the die  210 . Once the tubing  220  is heated, warm compressed air can be blown to expand the polyethylene tubing  220  against the cooler inner walls of the mold  210  which can be held slightly below the melting temperature of the polyethylene tubing  220 . When the flow of warm expansion air is shut off, the tubing  220  has expanded against the walls of the mold  210  and sets in the net or normal “as manufactured” shape. Then the molded balloon  60  can be extracted by opening the die  210  to release the balloon  60 . The dashed lines show the expansion stages of the polyethylene tubing  220  as it expands towards the mold walls  210 . The natural tendency of the hot tubing  220  is to expand as a sphere until the expanding material contacts the walls of the die  210 . As a consequence, different portions of the balloon membrane  65  (see  FIG. 2 ) will be thinner than others and may taper between the thick and thin portions. For example, the portions of the tubing  220  that form the proximal collar  68  and distal collar  67  will expand not at all or very slightly and will be thicker than the balloon membrane  65  at the points of largest expansion away from the longitudinal axis. The shape of the balloon can affect the location of the thick and thin membrane  65  portions and a stiffened disk may be found near the proximal and distal collars  67 ,  68  which can affect the manner in which the balloon  60  expands (see  FIGS. 13-16 ). This thickening could affect or restrict the displacement of the guide tip  62  from tissue contact by creating a more rigid “island” of membrane  65  around the distal tip  62  that may explain the deflection behavior described previously. In an alternate embodiment, the balloon  60  can be further stiffened in local areas by a dipping process to build up the balloon wall thickness. For example, the same material as the balloon membrane  65  can be used (such as polyurethane), or alternate dipping material may be used. 
         [0085]    With some embodiments of the balloon such as that found in  FIG. 12 , a tension or pulling force may be applied to the cannula  70  to pull the balloon  60   c  into contact with the seal cap  40   c  to create a seal. It may be further desirable to include a lock or clamp mechanism  250  to hold the cannula  70  relative to the endoscope to ensure that the fluid tight seal is maintained in all tissue contacting situations.  FIG. 21  illustrates an embodiment of a clamp mechanism  250  that can be used to clamp or lock the tensioned cannula  70  relative to the endoscope  100  to maintain a sealing contact between balloon  60   c  and seal cap  40   c . Clamp mechanism  250  comprises a releasably lockable clamp mechanism that contacts and grips cannula  70  and is actuated and released via a pull member  252  to clamp the cannula  70 . Alternate clamp mechanisms such as clamp mechanism  260  can surround the cannula  70  and retain it in place via frictional contact. One example of clamp member  260  would be a biopsy valve  108  or an adaption thereof wherein the biopsy valve  108  grips the endoscope  100  and the cannula  70  with an elastomeric material. And, in yet another embodiment of a clamp mechanism, the proximal sleeve  68  of the balloon may be configured to expand within the operative channel  102  of the endoscope  100  to lock the inflated balloon to the end of the endoscope. When the balloon is deflated, the proximal sleeve  68  unlocks from the operative channel  102 . 
         [0086]      FIG. 22  shows an alternate embodiment of a clamping mechanism  270  that could be configured to replace the previously described hollow balloon insertion tube  80  with a clamping mechanism  270  that combines a hollow balloon insertion tube  280  with a user actuated clamp  282 . The clamping mechanism  270  has a longitudinal hollow that would slide freely over the cannula  70  and the collapsed balloon  60   c  could reside within (not shown). The hollow balloon insertion tube  280  can be configured to fit within the operative channel  102  of the endoscope and the biopsy valve  108  (if provided). The hollow balloon insertion tube  280  may be sized to be inserted into the operative channel  102  to a position past a “Y” branch of the channel  102 . The collapsed balloon  60   c  can then be introduced into the instrument passage  102  of the endoscope  100  without direct contact with the “Y”. Once the balloon  60   c  was extended from the scope and inflated, the clamping mechanism  270  could be pushed inward to bring a stop collar  288  into contact with the proximal opening of the instrument passage, or the biopsy valve  108  (if present). Pulling on the handle  50  or the cannula  70  while pushing on the clamping mechanism  270  can ensure a seal between the balloon  60   c  and the seal cap  40   c  (not shown). Locking the user actuated clamp  282  ensures the seal is locked and maintained between balloon  60   c  and the seal cap  40   c . As shown in  FIG. 22  but not limited thereto, the user actuated clamp  282  can comprise a deflectable cantilever beam  284  that can, when deflected, simultaneously clamp on the cannula  70  and lock with a clamp arm  286 . The clamp arm  286  can also be a cantilever, and can be deflected to release the deflectable cantilever beam  284  to unlock the user actuated clamp  282 , and to release the cannula  70 . Stop collar  288  can be used to contact and push against the endoscope or the biopsy valve  108  to maintain tension on the cannula  70 . 
         [0087]    Turning now to  FIG. 23 , a front view of the front face  104  of the endoscope is shown. The operative channel  102  of the endoscope is non-concentrically disposed in the endoscope, and accordingly the catheter  70  and balloon are non-concentrically disposed relative to a central axis of the endoscope. As described previously, when the cap  40  and balloon  60  are installed on the endoscope, pulling on the catheter seals the balloon  60  against the cap  40  and the non-concentrically disposed balloon  60  is free to pivot somewhat about the attachment point to the cannula  70  to center itself in the seal cap  40 . 
         [0088]    During operation, as the balloon  60  pushes tangentially against the intestinal wall, the force attempts to unseat the balloon from the cap. The flaring portions of the cap, shown in  FIG. 9  for example, seat the balloon to prevent the seal between the balloon and the cap from being broken or otherwise compromised. Additionally or alternatively, the cap, for example the cap shown in  FIGS. 9-12 , may include one or more longitudinal cuts in a portion of the cap protruding past the distal end  106  of the endoscope to prevent the balloon from being unseated from the cap when the balloon pushes against the intestinal wall. Alternatively, the portion of the cap protruding past the distal end  106  of the endoscope may have portions of varying heights to seal with the balloon. 
         [0089]    While the present medical apparatus has been illustrated by description of several embodiments, additional advantages and modifications may readily appear to those skilled in the art. For example, in embodiments, the seal cap  40  can be configured to grip the balloon  60  and the endoscope  100 , thereby securing the balloon  60  to the endoscope  100 . 
         [0090]    Although the invention has been shown and described with respect to a certain embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.