Abstract:
A self propelled, endoscopic apparatus formed of a flexible, fluid-filled toroid and a motorized or powerable frame The apparatus may be used to advance a variety of accessory devices into generally tubular spaces and environments for medical and non-medical applications. The apparatus when inserted into a tubular space or environment, such as the colon of a patient undergoing a colonoscopy, is advanced by the motion of the toroid. The toroid&#39;s surface circulates around itself in a continuous motion from inside its central cavity along its central axis to the outside where its surface travels in the opposite direction until it again rotates into its central cavity. As the device advances within the varying sizes, shapes and contours of body lumens, the toroid compresses and expands to accommodate and navigate the environment. The motion of the toroid can be powered or unpowered and the direction and speed may be controlled. The apparatus may be used to transport a variety of accessory devices to desired locations within tubular spaces and environments where medical and non-medical procedures may be performed.

Description:
RELATED APPLICATIONS  
       [0001]    The present application claims the benefit of U.S. Provisional Patent Application, Serial No. 60/462,787, filed Apr. 14, 2003. The entire disclosure of the above-mentioned application is hereby incorporated by reference. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    This invention relates to an apparatus useful in medical and non-medical applications to introduce accessory devices into collapsible and non-collapsible, body cavities or canals, pipes, lumens and other generally tubular spaces or environments. More particularly, the invention relates to a propulsion system for endoscopic systems.  
         BACKGROUND OF THE INVENTION  
         [0003]    An endoscope is any instrument used to obtain a view of the interior of a patient&#39;s body using a variety of means to capture and transmit the view to an observer. Endoscopes can also be used to perform a variety of diagnostic and interventional procedures such as biopsies and other small surgical procedures. Examples of endoscopes include: a colonoscope used within the colon, a gastroscope used inside the stomach, and a bronchoscope used within the trachea and bronchi. Endoscopes are often inserted into body cavities or lumens via natural orifices but can also be inserted into incisions to gain access to areas of the body where no natural entrance exists.  
           [0004]    Traditional endoscopes consist of a rigid or flexible rod or shaft with a means of collecting and transmitting an image from inside the patient&#39;s body. The rod or shaft is inserted and pushed to the location of interest. The rod or shaft typically surrounds a number of pathways used to house fiber optic cables and route instruments, catheters, devices, gasses, liquids and other substances in and out of the area of interest.  
           [0005]    Traditional endoscopes require a minimal rigidity for successful insertion and work well when the body cavity or canal, or other lumens having curves and turns. However, when it is constricted, convoluted and consists of many curves, as is the case with the colon, it can be difficult or impossible to push the endoscope to its desired location. Steerable articulating endoscopes are often used to make navigation of turns easier; however, the increased friction associated with each additional turn limits the number of turns that can be navigated successfully and ultimately limits the distance an endoscope can be introduced into the patient&#39;s body. In addition, the increased force required to complete more turns and corners raises the risk of complications such as bowel perforation as well as the discomfort and pain experienced by the patient. It would be useful to have an apparatus for endoscopic medical procedures that can navigate in such environments and can overcome the physical and procedural limitation of traditional endoscopes. It would further be useful if such an apparatus were self-propelled.  
           [0006]    Endoscopic devices may also be utilized in non-medical or commercial and industrial applications to obtain views from or introduce instruments or devices into generally tubular spaces or environments such as lumens, sections of pipe or other structures, which may have a number of curves and turns. Such tubular spaces or environments may be partially occluded or have buildup on their interior surfaces and thus present a irregular internal shape or diameter. To navigate through such spaces and environments, it would be useful to have a device or apparatus that can adapt to the internal shape or diameter of the space or environment into which it is introduced and of further use if the apparatus were self-propelled.  
         SUMMARY OF THE INVENTION  
         [0007]    The invention in it various embodiments is a propulsion apparatus that can be used to transport accessory devices within body cavities or canals, sections of pipe, lumens, and other generally tubular spaces and environments and is generally comprised of a toroid and a powered or motorized frame. The motion of the toroid can be powered or unpowered and the direction and speed may be controlled.  
           [0008]    In an embodiment of the invention, the apparatus is comprised of a toroid and a frame. The toroid is a fluid-filled, enclosed ring formed of a flexible material. The enclosed ring defines a central cavity, having an interior volume and presenting an exterior surface and an interior surface which move continuously in opposite directions when the apparatus is in motion.  
           [0009]    In one embodiment, the frame is formed of a support structure, a housing structure and a series of at least two sets of interlocking rollers or skids located on the support and housing structures. The support structure is located within the interior volume of the enclosed ring. The housing structure is concentrically and coaxially located relative to the support structure and disposed in the central cavity of the enclosed ring. The rollers or skids are located so as to maintain the two structures in a fixed spatial relationship with the flexible material of the enclosed ring being positioned between the two structures and the rollers or skids located thereon.  
           [0010]    In another embodiment, the frame is formed of a support structure located within the interior volume of the enclosed ring and a series of at least two sets of interlocking rollers or skids located on the support structure. The rollers or skids are located so as to maintain the flexible material of the enclosed ring between them.  
           [0011]    In other embodiments of the invention, the apparatus is a propulsion apparatus for transport of accessory devices. The apparatus is comprised of a toroid and a powered frame. The toroid is a fluid-filled, enclosed ring formed of a flexible material. The enclosed ring defines a central cavity and has an interior volume. The powered frame is formed of a support structure and housing structure or a support structure alone. A series of at least two sets of interlocking rollers or skids located on the support and housing structures or on the support structure in the case there is no housing structure. The support structure is located within the interior volume of the enclosed ring. The housing structure is concentrically and coaxially located relative to the support structure and disposed within the central cavity of the enclosed ring. The rollers or skids are located so as to maintain the two structures in a fixed spatial relationship with the flexible material of the enclosed ring being positioned between the two structures and the rollers or skids located thereon. The rollers may be connected to a power source and when powered provides a motive, directional force to the flexible material.  
           [0012]    In its various embodiments, the apparatus of the invention may further comprise at least one accessory device. Depending upon whether the apparatus is to be used for medical or non-medical applications, the at least one accessory device may be selected from the group consisting of endoscopes, cameras, video processing circuitry, fiber optic cables, electronic communication cables, lasers, surgical instruments, medical instruments, diagnostic instruments, instrumentation, sensors, stent catheters, fluid delivery devices, drug delivery devices, electronic devices, tools, sampling devices, assay devices, articulating segments, cables to articulate the articulating segments, other accessory devices, and combinations thereof.  
           [0013]    The apparatus of the invention may further comprise a power source connected to the rollers which when powered provide a motive force to the flexible material of the enclosed ring. The power source may be an external power source or an internal power source and may be transmitted through the shaft by various means.  
           [0014]    In its various embodiments, the apparatus of the invention may further comprise an accessory tube. The accessory tube has at least one pathway through which accessory devices can be inserted into the patient or connected to external supporting devices.  
           [0015]    The apparatus of the invention may be utilized to perform medical or non-medical procedures. In an embodiment of a procedure according to the invention, the apparatus is utilized for medical procedures. The procedure of this embodiment comprising the steps of: introducing a self-propellable, endoscopic apparatus according to the invention into the rectum and anal canal of a patient, the apparatus being equipped with at least one accessory device and connected to at least one external support device; powering the apparatus to propel the apparatus forward through the anal canal and into the colon up to a location in the colon at which at least one medical procedure is to be performed; performing the at least one medical procedure with the at least one accessory device; optionally, serially propelling the apparatus to another location in the colon at which the at least one medical procedure is to be performed and performing said at least one medical procedure; propelling the apparatus backward through the colon and into the anal canal; and removing the apparatus from the patient.  
           [0016]    In another embodiment of the invention, an endoscopic procedure is provided. The endoscopic procedure comprises the steps of: introducing a self-propellable, endoscopic apparatus into the generally tubular space or environment, the apparatus being equipped with at least one accessory device and connected to at least one external support device; powering the apparatus to propel and navigate the apparatus forward in the tubular space to a location at which at least one endoscopic procedure is to be performed; performing the at least one endoscopic procedure with the at least one accessory device; optionally, serially propelling the apparatus to another location in the tubular space at which the at least one endoscopic procedure is to be performed and performing said at least one endoscopic procedure; propelling the apparatus backward through tubular space; and removing the apparatus from the tubular space. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    [0017]FIG. 1 is a sectional view of an apparatus in accordance with an exemplary embodiment of the invention.  
         [0018]    [0018]FIG. 2 is a sectional view of an apparatus in accordance with an additional exemplary embodiment of the invention.  
         [0019]    [0019]FIG. 3 is an axial cross-sectional view of an apparatus in accordance with an exemplary embodiment of the present invention.  
         [0020]    [0020]FIG. 4 is an axial cross-sectional view of an apparatus in accordance with an additional exemplary embodiment of the present invention.  
         [0021]    [0021]FIG. 5 is an enlarged, partial, cross-sectional view of an apparatus in accordance with an exemplary embodiment of the invention.  
         [0022]    [0022]FIG. 6 is an enlarged, partial, cross-sectional view of an apparatus in accordance with an exemplary embodiment of the invention.  
         [0023]    [0023]FIG. 7 is an enlarged, partial, cross-sectional view of an apparatus in accordance with an additional exemplary embodiment of the invention.  
         [0024]    [0024]FIG. 8 is an enlarged, partial, cross-sectional view of an apparatus in accordance with an exemplary embodiment of the invention.  
         [0025]    [0025]FIG. 9 is an enlarged, partial cross-sectional view of an apparatus in accordance with an additional exemplary embodiment of the invention.  
         [0026]    [0026]FIG. 10 is an additional enlarged, partial cross-sectional view of the apparatus shown in the previous figure.  
         [0027]    [0027]FIG. 11 is an enlarged, partial, cross-sectional view of an apparatus in accordance with an exemplary embodiment of the invention.  
         [0028]    [0028]FIG. 12 is an additional enlarged, partial cross-sectional view of the apparatus shown in the previous figure.  
         [0029]    [0029]FIG. 13 is an enlarged, partial cross-sectional view of an apparatus in accordance with an additional exemplary embodiment of the present invention.  
         [0030]    [0030]FIG. 14 is a cross-sectional view of a bladder in accordance with an exemplary embodiment of the present invention.  
         [0031]    [0031]FIG. 15 is an additional cross-sectional view of bladder shown in the previous figure. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0032]    The self-propellable or self-propelled endoscopic system or apparatus of the invention can be utilized to transport a variety of accessory devices to desired locations within a number of generally tubular spaces and environments, both collapsible and non-collapsible, for medical, industrial and commercial applications. With the system of the invention, an operator, such as a doctor, medical or other technician, can navigate and traverse within generally tubular spaces and/or environments whether of standard or non-standard dimensions and/or of uniform or non-uniform quality that cause difficulty when navigated by pushing a rod or “snake” through it. Examples of such spaces or environments would include, but are not limited to a circular, square, rectangular, or other shaped tube or a tube presenting one or more such shapes along its length that is partially occluded or interior surface of which is irregular, possibly due to material buildup on the surface. And may further include a route with varying diameters, constrictions and curves.  
         [0033]    [0033]FIG. 1 is a sectional view of an apparatus  100  in accordance with an exemplary embodiment of the invention. With reference to FIG. I it will be appreciated that the system or apparatus  100  of the invention employs a toroid  102 . In the embodiment of FIG. 1, the toroid  102  comprises a bladder  104  of a flexible material  106 . The flexible material  106  of bladder  104  has an interior surface  120  and an exterior surface  122 . Interior surface  120  of flexible material  106  defines an interior volume  124  of bladder  104 . In some embodiments of the present invention, interior volume  124  of bladder  104  contains or is filled with a fluid, a gas, liquid or combination thereof. Exterior surface  122  of flexible material  106  defines a central cavity  126 .  
         [0034]    The apparatus  100  shown in FIG. 1 also includes a frame  108 . Frame  108  both supports and interacts with flexible material  106  of bladder  104 . Frame  108  is formed of a support structure  128  and a housing structure  130 . With reference to FIG. 1, it will be appreciated that housing structure  130  is disposed in central cavity  126  defined by exterior surface  122  of flexible material  106  of bladder  104 . Also with reference to FIG. 1, it will be appreciated that support structure  128  is disposed within interior volume  124  defined by interior surface  120  of flexible material  106  of bladder  104 .  
         [0035]    Support structure  128  and housing structure  130  each rotatably support a plurality of rollers. In FIG. 1, a pair of motive rollers  134  are shown contacting flexible material  106  of bladder  104 . In the embodiment of FIG. 1, rotation of motive rollers  134  will cause flexible material  106  to move relative to the rotational axis of each motive roller  134 . In the embodiment of FIG. 1, each motive roller  134  comprises a plurality of teeth  140 . With reference to FIG. 1, it will be appreciated that the teeth  140  of each motive roller  134  mate with a first thread  142  of a worm gear  144 . Accordingly, in the embodiment of FIG. 1, rotation of worm gear  144  will cause motive rollers  134  to rotate.  
         [0036]    The power for rotating motive rollers  134  can be any of a variety of internal or external power sources known to those skilled in the art to be suitable for the given application. In the case of electrical power, the power source may be stored inside the apparatus, or the power may be transmitted via wires from outside the patient or space through an accessory tube (not shown) connected to the apparatus or to one or more electrical motors located inside the housing structure or otherwise operatively connected to motive rollers  134  and/or worm gear  144 . The electrical motors, in turn, power the motive rollers  134  and/or worm gear  144 . In the case of mechanical power, rollers  134  and/or worm gear  144  may be powered by a thin, flexible, spinning rod or wire powered from a remote motor located outside the patient or space. The motion of the rod or wire is transmitted to the rollers located on the housing structure. Mechanical power may also be transmitted by a spinning spiral or spring component located inside or outside of the apparatus. This power may be manually generated.  
         [0037]    In the embodiment of FIG. 1, housing structure  130  rotatably supports a plurality of stabilizing rollers  136 . With reference to FIG. 1, it will be appreciated that each stabilizing roller  136  contacts exterior surface  122  of flexible material  106  of bladder  104 . In the embodiment of FIG. 1, a suspended stabilizing roller  138  is located proximate each stabilizing roller  136 . Each suspended stabilizing roller  138  contacts interior surface  120  of flexible material  106  of bladder  104 . In the embodiment of FIG. 1, each suspended stabilizing roller  138  defines a groove  146  that is dimensioned to receive a portion of flexible material  106  and a portion of a stabilizing roller  136 .  
         [0038]    In the embodiment of FIG. 1, each suspended stabilizing roller  138  is pivotally coupled to an arm  148 . In some useful embodiments of the present invention, each arm  148  and suspended stabilizing roller  138  act to bias exterior surface  122  of flexible material  106  against a stabilizing roller  136 . Also in FIG. 1, a plurality of suspended motive rollers  132  are disposed proximate each motive roller  134 . Each suspended motive roller  132  is pivotally supported by support structure  128 . In some useful embodiments of the present invention, support structure  128  and suspended motive rollers  132  act to bias exterior surface  122  of flexible material  106  against motive rollers  134 .  
         [0039]    For some applications, bladder  104  may be generally longer than it is wide. However, for other applications or depending upon the size or dimension of the space or environment into which the toroid  102  is to be introduced, the bladder  104  may be of substantially equal length and width or may be wider than it is long.  
         [0040]    [0040]FIG. 2 is a sectional view of an apparatus  200  in accordance with an additional exemplary embodiment of the invention. With reference to FIG. 2 it will be appreciated that apparatus  200  comprises a bladder  204  that is generally toroidal or ring shaped. Bladder  204  comprises a flexible material  206 . Flexible material  206  of bladder  204  has an interior surface  220  and an exterior surface  222 . Interior surface  220  of flexible material  206  defines an interior volume  224  of bladder  204 . In some embodiments of the present invention, interior volume  224  of bladder  204  contains or is filled with a fluid, a gas, liquid or combination thereof. Exterior surface  222  of flexible material  206  defines a central cavity  226 .  
         [0041]    The apparatus  200  shown in FIG. 2 also includes a frame  208 . Frame  208  both supports and interacts with the flexible material  206  of the bladder  204 . Frame  208  comprises a support structure  228  and a housing structure  230 . With reference to FIG. 2, it will be appreciated that housing structure  230  is disposed in central cavity  226  defined by exterior surface  222  of flexible material  206  of bladder  204 . Also with reference to FIG. 2, it will be appreciated that support structure  228  is disposed within interior volume  224  defined by interior surface  220  of flexible material  206  of bladder  204 .  
         [0042]    Support structure  228  and housing structure  230  each rotatably support a plurality of rollers. In FIG. 2, a plurality motive rollers  234  are shown contacting flexible material  206  of bladder  204 . In the embodiment of FIG. 2, rotation of motive rollers  234  is capable of causing flexible material  206  to move relative to the rotational axis of each motive roller  234 . In the embodiment of FIG. 2, each motive roller  234  comprises a plurality of teeth  240 . Each motive roller  234  is capable of mating with a worm gear  244 .  
         [0043]    With reference to FIG. 2, it will be appreciated that worm gear  244  comprises a first thread  242  and a second thread  243 . In FIG. 2, the teeth  240  of a first set of motive roller  234  are shown mating with first thread  242  of worm gear  244 . Accordingly, in the embodiment of FIG. 2, rotation of worm gear  244  will cause the first set of motive rollers  234  to rotate.  
         [0044]    In some embodiments of an apparatus in accordance with an exemplary embodiment of the present invention, a one or more motive rollers are powered by a worm gear. A housing structure of the apparatus may contain a hollow cavity to hold the worm gear in place as illustrated, for example, in FIG. 2. This hollow cavity allows the worm gear  244  to rotate relative to housing structure  230 . Worm gear  244  may also move forwards and backward along the central axis of the apparatus in the embodiment of FIG. 2. This movement allows second thread  243  of worm gear  244  to selectively engage a second set of motive rollers while first thread  242  disengages from first set of motive rollers  234 . This selective engagement may facilitate forwards and backwards movement of the apparatus. In a variation of this embodiment, the apparatus may be configured so that the first and the second set of motive rollers  234  respectively engage first and second threads  242 ,  243 .  
         [0045]    In the embodiment of FIG. 2, housing structure  230  rotatably supports a plurality of stabilizing rollers  236 . With reference to FIG. 2, it will be appreciated that each stabilizing roller  236  contacts the exterior surface  222  of flexible material  206  of bladder  204 . In the embodiment of FIG. 2, a plurality of suspended stabilizing rollers  238  are located proximate each stabilizing roller  236 . Each suspended stabilizing roller  238  contacts interior surface  220  of flexible material  206  of bladder  204 . In some useful embodiments of the present invention, each suspended stabilizing roller  238  acts to bias exterior surface  222  of flexible material  206  against a stabilizing roller  236 .  
         [0046]    With continuing reference to FIG. 2, a suspended motive roller  232  is disposed proximate each motive roller  234 . Each suspended motive roller  232  is pivotally supported by support structure  228 . In some useful embodiments of the present invention, support structure  228  and suspended motive rollers  232  act to bias exterior surface  222  of flexible material  206  against motive rollers  234 .  
         [0047]    Various embodiments of housing structure  230  and support structure  228  are possible without deviating from the spirit and scope of the present invention. One exemplary embodiment may be viewed as two tubes positioned with one inside the other. The outer tube being the support structure which is located within the interior volume of the enclosed ring or bladder. The inner tube being the housing structure which is located within the central cavity. In another embodiment exemplary embodiment, either the support structure, the housing structure or both may be comprised of a series of one or more beams that may or may not form the general shape of a cylinder.  
         [0048]    The housing and support structures may be, for example, cylindrical with a circular cross section or they may have a cross section in the shape of a square, rectangle, triangle, hexagon or any other shape with straight or curved surfaces or any combination thereof. The frame structures may also be comprised of multiple cross sectional shapes throughout its length. The flexible material  206  of the bladder  204  surface runs between the two tubes which are spaced in fixed relationship relative to each other. The distance between the two tubes is sufficient to accommodate the interlocking rollers or skids and to allow the flexible material  206  for bladder  204  to pass between the support and housing structures even if the material folds over itself or is bunched up.  
         [0049]    [0049]FIG. 3 is an axial cross-sectional view of an apparatus  300  in accordance with an exemplary embodiment of the present invention. Apparatus  300  includes a bladder  304  comprising a flexible material  306 . The flexible material  306  of bladder  304  has an interior surface  320  and an exterior surface  322 . Interior surface  320  of flexible material  306  defines an interior volume  324  of bladder  304 . In some embodiments of the present invention, interior volume  324  of bladder  304  contains or is filled with a fluid, a gas, liquid or combination thereof. Exterior surface  322  of flexible material  306  defines a central cavity  326 .  
         [0050]    In the embodiment of FIG. 3, a housing structure  330  is disposed in central cavity  326  defined by exterior surface  322  of flexible material  306  of bladder  304 . The housing structure  330  rotatably supports a plurality of motive rollers  334 . In FIG. 3, motive rollers  334  are shown contacting exterior surface  322  of flexible material  306 . In the embodiment of FIG. 3, each motive roller  334  comprises a plurality of teeth  340 . The teeth  340  of each motive roller  334  mate with a thread  342  of a worm gear  344 . Thus, in the embodiment of FIG. 3, rotation of worm gear  344  will cause motive rollers  334  to rotate. Also in the embodiment of FIG. 3, rotation of the motive rollers  334  will cause flexible material  306  to move relative to the rotational axis of each motive roller  334 .  
         [0051]    With continuing reference to FIG. 3, it will be appreciated that a support structure  328  is disposed within an interior volume  324  defined by the interior surface  320  of flexible material  306 . In the embodiment of FIG. 3, support structure  328  rotatably supports a plurality of suspended motive rollers  332 . In FIG. 3, one suspended motive roller  332  is shown disposed proximate each motive roller  334 . Also in FIG. 3, each suspended motive roller  332  can be seen contacting interior surface  320  of flexible material  306  of bladder  304 . In some useful embodiments of the present invention, support structure  328  and suspended motive rollers  332  act to bias exterior surface  322  of flexible material  306  against motive rollers  334 .  
         [0052]    In the exemplary embodiment of FIG. 3, housing structure  330  and support structure  328  each have a generally tubular shape. Thus, housing structure  330  and support structure  328  may be viewed as two tubes positioned with one inside the other. The outer tube being support structure  328  which is located within interior volume  324  defined by interior surface  320  of bladder  304 . The inner tube being housing structure  330  which is located within central cavity  326  defined by exterior surface  322  of bladder  304 .  
         [0053]    It will be appreciated that various embodiments of housing structure  330  and support structure  328  are possible without deviating from the spirit and scope of the present invention. The housing and support structures may be, for example, cylindrical with a circular cross section or they may have a cross section in the shape of a square, rectangle, triangle, hexagon or any other shape with straight or curved surfaces or any combination thereof. The frame structures may also be comprised of multiple cross sectional shapes throughout their length. The flexible material  306  of the bladder  304  surface runs between the two structures which are spaced in fixed relationship relative to each other. The distance between the two structures is sufficient to accommodate the interlocking rollers or skids and to allow the flexible material  306  for bladder  304  to pass between the support and housing structures even if the material folds over itself or is bunched Up.  
         [0054]    [0054]FIG. 4 is an axial cross-sectional view of an apparatus  400  in accordance with an additional exemplary embodiment of the present invention. Apparatus  400  comprises a bladder  404  of a flexible material  406 . In FIG. 4 a support structure  428  is shown disposed within an interior volume  424  defined by the interior surface  420  of flexible material  406 . In the embodiment of FIG. 4, support structure  428  rotatably supports a plurality of suspended stabilizing rollers  438 . With reference to FIG. 4, it will be appreciated that each suspended stabilizing roller  438  contacts the interior surface  420  of flexible material  406  of bladder  404 . In some useful embodiments of the present invention, support structure  428  and suspended stabilizing roller  438  act to bias exterior surface  422  of flexible material  406  against a stabilizing roller  436 .  
         [0055]    In the embodiment of FIG. 4, a housing structure  430  is disposed in a central cavity  426  defined by an exterior surface  422  of flexible material  406  of bladder  404 . Housing structure  430  rotatably supports a plurality of stabilizing rollers  436 . With reference to FIG. 4, it will be appreciated that each stabilizing roller  436  contacts the interior surface  420  of flexible material  406  of bladder  404 . In the embodiment of FIG. 4, each suspended stabilizing roller  438  defines a groove  446  that is dimensioned to receive a portion of flexible material  406  and a portion of a stabilizing roller  436 .  
         [0056]    [0056]FIG. 5 is an enlarged, partial, cross-sectional view of an apparatus in accordance with an exemplary embodiment of the invention. Apparatus  500  comprises a housing structure  530  and a support structure  528 . Housing structure  530  rotatably supports a motive roller  534  and support structure  528  rotatably supports a plurality of suspended motive rollers  532 . A flexible material  506  is disposed between motive roller  534  and suspended motive rollers  532 . Flexible material  506  may form, for example, a portion of a bladder in accordance with the present invention. Suspended motive rollers  532  are rotatably supported by a support structure  528 . In the embodiment of FIG. 5, housing structure  530  rotatably supports a worm gear  544 . A first thread  542  of worm gear  544  engages teeth  540  of motive roller  534 . In the embodiment of FIG. 5, rotation of worm gear  544  will cause motive roller  534  to rotate. Rotation of motive roller  534 , in turn, causes flexible material  506  to move relative to housing structure  530 . With reference to FIG. 5, it will be appreciated that flexible material  506  has an interior surface  520  and an exterior surface  522 .  
         [0057]    [0057]FIG. 6 is an enlarged, partial, cross-sectional view of an apparatus  600  in accordance with an exemplary embodiment of the invention. Apparatus  600  comprises a housing structure  630  that rotatably supports a worm gear  644 . A first thread  642  of worm gear  644  engages the teeth  640  of a motive roller  634 . Motive roller  634  is rotatably supported by housing structure  630 . A flexible material  606  is disposed between motive roller  634  and a skid  650 . Flexible material  606  may form, for example, a portion of a bladder in accordance with the present invention.  
         [0058]    In the embodiment of FIG. 6, rotation of worm gear  644  causes rotation of motive roller  634 . Rotation of motive roller  634 , in turn, causes flexible material  606  to move relative to housing structure  630 . With reference to FIG. 6, it will be appreciated that skid  650  contacts an interior surface  620  of flexible material  606 . In some useful embodiments of the present invention, skid  650  acts to bias an exterior surface  622  of flexible material  606  against motive roller  634 .  
         [0059]    [0059]FIG. 7 is an enlarged, partial, cross-sectional view of an apparatus  603  in accordance with an additional exemplary embodiment of the invention. Apparatus  603  comprises a housing structure  630  that rotatably supports a motive roller  634 . A flexible material  606  is disposed between motive roller  634  and a skid  650 . In the embodiment of FIG. 7, a pair of springs  652  act to bias skid  650  against an interior surface  620  of flexible material  606 . Springs  652  are diagrammatically illustrated in FIG. 7. Springs  652  may comprise, for example, sheet metal arms. A compression motion and an extension motion of springs  652  and skid  650  are illustrated with arrows in FIG. 7.  
         [0060]    In some useful embodiments of the present invention, skid  650  and springs  652  act to bias an exterior surface  622  of flexible material  606  against motive roller  634 . Teeth  640  of motive roller  634  engage a first thread  642  of a worm gear  644  that is rotatably supported by housing structure  630 . In the embodiment of FIG. 7, rotation of worm gear  644  causes rotation of motive roller  634 . Rotation of motive roller  634 , in turn, causes flexible material  606  to move relative to housing structure  630 .  
         [0061]    [0061]FIG. 8 is an enlarged, partial, cross-sectional view of an apparatus in accordance with an exemplary embodiment of the invention. Apparatus  700  includes a frame  708  comprising a housing structure  730  and a support structure  728 . Housing structure  730  rotatably supports a motive roller  734  and support structure  728  rotatably supports a plurality of suspended motive rollers  732 . A flexible material  706  is disposed between motive roller  734  and suspended motive rollers  732 .  
         [0062]    Suspended motive rollers  732  are rotatably supported by a support structure  728 . A pair of springs  752  of support structure  728  are diagrammatically illustrated in FIG. 8. In the embodiment of FIG. 8, springs  752  act to bias suspended motive rollers  732  against an interior surface  720  of flexible material  706 . Springs  752  may comprise, for example, sheet metal arms. A compression motion and an extension motion of springs  752  and suspended motive rollers  732  are illustrated with arrows in FIG. 8.  
         [0063]    In the embodiment of FIG. 8, housing structure  730  rotatably supports a worm gear  744 . A first thread  742  of worm gear  744  engages teeth  740  of motive roller  734 . In the embodiment of FIG. 8, rotation of worm gear  744  will cause motive roller  734  to rotate. Rotation of motive roller  734 , in turn, causes flexible material  706  to move relative to housing structure  730 .  
         [0064]    [0064]FIG. 9 is an enlarged, partial cross-sectional view of an apparatus  800  in accordance with an additional exemplary embodiment of the invention. With reference to FIG. 9 it will be appreciated that apparatus  800  comprises a bladder  804 . In some embodiments of the present invention, bladder has a generally toroidal or ring shape. Bladder  804  comprises a flexible material  806 . Flexible material  806  of bladder  804  has an interior surface  820  and an exterior surface  822 . Interior surface  820  of flexible material  806  defines an interior volume  824  of bladder  804 . In some embodiments of the present invention, interior volume  824  of bladder  804  contains or is filled with a fluid, a gas, liquid or combination thereof. Exterior surface  822  of flexible material  806  defines a central cavity  826 .  
         [0065]    The apparatus  800  shown in FIG. 9 also includes a frame  808 . Frame  808  both supports and interacts with the flexible material  806  of the bladder  804 . Frame  808  comprises a support structure  828  and a housing structure  830 . In the embodiment of FIG. 9, housing structure  830  rotatably supports a stabilizing roller  836  and support structure rotatably supports a suspended stabilizing roller  838 . With reference to FIG. 9, it will be appreciated that suspended stabilizing roller  838  contacts the interior surface  820  of flexible material  806  of bladder  804 . Stabilizing roller  836  is shown contacting an exterior surface  822  of flexible material  806  of bladder  804 . The rotation of the rollers and the movement of flexible material  806  are illustrated with arrows in FIG. 9.  
         [0066]    [0066]FIG. 10 is an additional enlarged, partial cross-sectional view of apparatus  800  shown in the previous figure. In some useful embodiments of the present invention, suspended stabilizing roller  838  acts to bias exterior surface  822  of flexible material  806  against stabilizing roller  836 . In the embodiment of FIG. 10, an arm  848  of Support structure  828  acts to bias suspended stabilizing roller  838  against interior surface  820  of flexible material  806 . A flexing motion of arm  848  is illustrated using arrows in FIG. 10.  
         [0067]    [0067]FIG. 11 is an enlarged, partial, cross-sectional view of an apparatus  900  in accordance with an exemplary embodiment of the invention. Apparatus  900  comprises a housing structure  930  that rotatably supports a worm gear  944 . A stabilizing roller  936  is rotatably supported by housing structure  930 . A flexible material  906  is disposed between stabilizing roller  936  and a skid  950 . Flexible material  906  may form, for example, a portion of a bladder in accordance with the present invention. With reference to FIG. 11, it will be appreciated that skid  950  contacts an interior surface  920  of flexible material  906 . In some useful embodiments of the present invention, skid  950  acts to bias an exterior surface  922  of flexible material  906  against stabilizing roller  936 .  
         [0068]    [0068]FIG. 12 is an additional enlarged, partial cross-sectional view of apparatus  900  shown in the previous figure. Skid  950  of apparatus  900  is shown in cross section in FIG. 12. With reference to FIG. 12, it will be appreciated that skid  950  defines a depression  956 . In the embodiment of FIG. 12, depression  956  is dimensioned to receive a portion of flexible material  906  and a portion of stabilizing roller  936 . The rotation of stabilizing roller  936  and the motion of flexible material  906  are illustrated with arrows in FIG. 12.  
         [0069]    [0069]FIG. 13 is an enlarged, partial cross-sectional view of apparatus  900  in accordance with an additional exemplary embodiment of the present invention. Apparatus  900  includes a frame  908  comprising a housing structure  930  and a support structure  928 . A stabilizing roller  936  is rotatably supported by housing structure  930 . A flexible material  906  is disposed between stabilizing roller  936  and a skid  950 . With reference to FIG. 13, it will be appreciated that skid  950  contacts an interior surface  920  of flexible material  906 . In some useful embodiments of the present invention, skid  950  acts to bias exterior surface  922  of flexible material  906  against stabilizing roller  936 . In the embodiment of FIG. 13, an arm  948  of support structure  928  acts to bias skid  950  against interior surface of flexible material  906 . A flexing motion of arm  948  is illustrated using an arrow in FIG. 13.  
         [0070]    [0070]FIG. 14 is a cross-sectional view of a bladder  104  in accordance with an exemplary embodiment of the present invention. Bladder  104  comprises a flexible material  106 . The movement of flexible material  106  is illustrated with arrows in FIG. 14. With reference to FIG. 14, an exterior portion of bladder  104  can be viewed as moving in one direction while an interior portion of bladder  104  is moving in the opposite direction. The result is that the entire shape can move along its central axis while the external material rolls around itself. Thus, the flexible material may be described as circulating around and through the frame in a continuous motion from inside the central cavity long is central axis to the outside where the exterior surface of the flexible material travels along in contact with the interior surface of a generally tubular space or environment or other lumen. A travel direction of bladder  104  is labeled TD in FIG. 14. This motion is well adapted to travel within a generally cylindrical or tubular space, even a collapsible one, such as exists with the colon or rectal canal. The entire object moves with minimal to no slipping because its exterior surface remains in relatively constant or continuous contact with the interior of the space while the interior surface of the flexible materials moves forward in the direction of travel as shown.  
         [0071]    [0071]FIG. 15 is an additional cross-sectional view of bladder  104  shown in the previous figure. In the embodiment of FIG. 15, bladder  104  is traveling a in second travel direction TD that is generally opposite the travel direction shown in the previous figure. The movement of flexible material  106  of bladder  104  is illustrated with arrows in FIG. 15. With reference to FIG. 15, an exterior portion of bladder  104  can be viewed as moving in one direction while an interior portion of bladder  104  is moving in the opposite direction.  
         [0072]    In some exemplary embodiments of an apparatus in accordance with the present invention, a frame is formed of a support structure and a series of at least two sets of interlocking rollers or skids located on the support structure. The support structure is located within the interior volume of the enclosed ring. The rollers or skids are located so as to maintain the flexible material of the enclosed ring between them. To further accommodate folds and wrinkles in the flexible material the rollers or skids may be suspended and may apply force to the flexible material and the matching rollers or skids. Embodiments of possible suspension mechanisms are illustrated in the figures.  
         [0073]    The ends of support and housing structures may be tapered for some applications. Embodiments of the invention having tapered ends are well-suited, but not necessary for medical applications and procedures, e.g., colonoscopy or rectal examination. However, such tapering is not necessary for all applications, particularly those involving spaces or environments of large dimension. The tapered ends of the support and housing structures may serve a number of functions, including, but not limited to allowing the two structures to fit and work together without sliding apart; presenting a smooth and gradual surface to over which the flexible material travels, and easing the apparatus&#39; through constrictions and its passage around curves and comers.  
         [0074]    The series of at least two sets of interlocking rollers or skids are located on the support and housing structures or in the case where only a support structure is utilized, the rollers or skids are located on the support structure. A set of rollers or skids may be comprised of one or more roller, one or more skid or combination thereof located on one or more of the structures. A set may be formed of a single roller or skid, a pair of adjacent rollers or skid, a single roller or skid on one structure and a pair comprised of two or more rollers, two or more skids or a combination of both on the other, and other variations and combinations of rollers and skids located in corresponding aligned position on each structure. The rollers or skids are interlocked in two directions, along and across the apparatus&#39; central axis. The interlocking is done in such a way as to maintain a generally constant or fixed distance between the support and housing structures, so that they are in a generally fixed spatial relationship. As shown in the figures, the flexible material of the enclosed ring passes between the rollers or skids. This helps to prevent the toroid&#39;s flexible material from being compressed between the two structures except where it interacts with the rollers or skids. When powered, the rollers engage the flexible material and provide a motive, directional force to the flexible material which allows the apparatus to move in a forward or backward direction. With the exterior surface of the enclosed ring contacting and conforming to the interior surface or surfaces of a generally tubular space or environment, the powering of the rollers moves the flexible material as illustrated in the figures. This movement of the flexible material provides the self-propulsion for the apparatus.  
         [0075]    If unpowered, the rollers or skids provide a means of facilitating the motion of the flexible material between the support and housing structures, for example when the apparatus is initially being introduced. When propelled, preferably, only the rollers on the advancing side of the apparatus are powered. This will tend to keep the flexible material from wrinkling, kinking and bunching-up by pulling the flexible material through the toroid&#39;s central cavity instead of pushing it. However, the apparatus can be operated with the rearward roller (rearward relative the direction of motion) being powered or both forward and rearward rollers being powered.  
         [0076]    The fluid-filled toroid is also well adapted to the numerous curves, comers and constrictions found in body cavities and lumens. As one part of the shape is squeezed or pushed the liquid or gas is displaced and accommodated by the flexibility of the bladder.  
         [0077]    The apparatus may include an accessory tube, such as a flexible tube, connected to the apparatus and leading outside the patient or other space into which it is introduced. For example, as the apparatus enters and travels within the patient, the tube remains connected and is pulled by the device. It can also be pushed or pulled as a means of moving the inside a patient or other space. The accessory tube can be a single pathway or conduit or may contain multiple pathways or conduits which can be used to insert a variety of accessory devices into the patient or to connect such devices to external support devices know to those skilled in the art, including but not limited to computers, analytical or diagnostic equipment or other electronic equipment appropriate to the given application.  
         [0078]    Various types of accessory devices can be utilized with or mounted to the apparatus. Such accessory devices include, but are not limited to, endoscopes, cameras, fiber optic cables, electronic communication cables, lasers, surgical instruments, medical instruments, diagnostic instruments, instrumentation, sensors, stent catheters, fluid delivery devices, drug delivery devices, electronic devices, tools, sampling devices, assay devices, other accessory devices, and combinations thereof.  
         [0079]    The material requirements for the various components of the invention can be fulfilled by a number of substances. For medical applications, all materials must possess a high degree of biocompatibility and be capable of withstanding sterilization methods know to those skilled in the art, such as radiation, steam or chemical vapor.  
         [0080]    The fluid located inside the enclosed ring or bladder may be a liquid, such as a light oil, water, saline solution, lubricant; a gas, such as air, nitrogen, or carbon dioxide; or a combination thereof. Preferably, for medical or veterinary application or use, the fluid will be non-toxic. For the enclosed ring or bladder the flexible material should be a material with puncture, rupture and abrasion resistance characteristic as appropriate to the conditions of the interior surface of the space or environment into which the apparatus will be introduced. The flexible material may also posses a textured surface that would assist its motion against the surface of the lumen it traverses. Other characteristics to be considered in the selection of suitable materials, for example, softness, flexibility and conformability. The toroid&#39;s material must also be capable of being sealed into an enclosed ring or closed bladder by some means such as heat sealing, an adhesive or a chemical bond. A variety of polymeric or plastic materials can be used as the flexible material.  
         [0081]    The support and housing structures may be formed of either a semi-flexible or semi- rigid material such as a polymer or a rigid material, such as stainless steel, a composite material or combinations thereof. The rollers or skids will require a material or group of materials that is high in strength and capable of being formed into very small parts. The roller material must also provide a sufficiently high degree of friction (not slip) against the flexible material without damaging it while the skids must provide a sufficiently low degree of friction (slip) against the flexible material without damaging it. The surfaces of the support and housing structures may be comprised of one or more materials that reduce or eliminate friction caused by the motion of the flexible material across the surfaces of the support and housing structures.  
         [0082]    For applications of a non-medical nature, the materials required must retain most properties described above but do not necessarily require biocompatibility or sterilization tolerance. The materials used for the invention in non-medical applications will require sufficient durability and compatibility to suit the environment in which they are to be used.  
         [0083]    Though a number of applications and uses of the apparatus of the invention have been identified herein above, additional applications and uses include, but are not limited to, inspection of difficult to reach pipes, tubes and caverns by carrying a camera or other optical, electrical or mechanical inspection device; transporting remotely controlled tools for use in difficult to reach locations; routing or pulling cable, wires rope, etc. through long narrow passages; pushing or pulling material through a pipe by taking advantage of the invention&#39;s ability to conform to the shape of its environment allowing it to provide a seal between the spaces on either side, i.e. the invention could facilitate emptying a pipe of material without mixing it with air or other material on the other side of the invention. Many of these applications would work equally well if the device was self-propelled or simply pushed or pulled from the outside.  
         [0084]    While exemplary embodiments of this invention and methods of practicing the same have been illustrated and described, it should be understood that various changes, adaptations, and modifications might be made therein without departing from the spirit of the invention and the scope of the appended claims.