PROPELLABLE APPARATUS WITH PASSIVE SIZE CHANGING
ABILITY
5
FIELD
This patent document relates generally to propellable apparatus  and more specifically  to a propellable apparatus with passive size changing ability.
10 BACKGROUND
Endoscopes are routinely used in medical procedures to view the interior of a patient""s body and to facilitate treatment of sites inside the body as atraumatically as possible. Some common types of endoscopes include: colonoscopes  such as to image or treat the colon  enteroscopes  such as for use
15 in the stomach or small bowel  and bronchoscopes  such as for use in the trachea or bronchi. Other instruments can also be useful when inserted into a body lumen or cavity  either with or without an accompanying endoscope.
OVERVIEW
20 One approach in facilitating use of an endoscope or other accessory
includes providing an apparatus that can facilitate its introduction into or removal from a body lumen or cavity  such as described in Ziegler et al. U.S. Patent No. 6 971 990  Ziegler et al. U.S. Patent Application No. 11/260 342 (which is published as U.S. Patent Application Publication No. 2006/0089533)
25 and Ziegler et al. U.S. Patent Application No. 11/825 528  the disclosures of each of which are incorporated by reference herein in their entirety  including their description of a propellable apparatus and related methods.
For example  a drive structure can be mounted on the endoscope or other accessory. The drive structure can propel a self-enclosed toroidal membrane 
30 such as to create propulsion force against the lumen or cavity wall. This can aid
in arivnring nr withrlrawina the pntincror nr nfhpr arrpccnry.
The present inventors have recognized  among other things  that there are several possible structures or methods that can be particularly advantageous such as when used to support this rotating toroidal membrane.
In some examples  an apparatus comprises a permeable or impermeable
5 self-enclosed tube. The tube can be sized and shaped to fit within and engage a human or animal body cavity. The tube can comprise an inner surface defining an enclosed region and an outer surface that turns outward to engage the body cavity and turns inward to encompass a central region defining a concentric longitudinal path. An attachment can be coupled to the tube. The attachment
10 can be configured to secure a payload. The tube can be powerable such as to provide relative movement of the tube relative to the cavity. This can help move the payload  with respect to the cavity  in at least one of a forward or reverse direction with respect to the longitudinal path. A compressible structure can be configured to bias the outer surface of the tube outward to engage the body
15 cavity at a first outer diameter. The compressible structure can be deformable inward in response to a compressive force from a stricture in the body cavity to provide a second outer diameter that is less than the first outer diameter.
To better illustrate the subject matter described herein  a non-limiting list of examples is provided here:
20 In Example 1  an apparatus comprises a self-enclosed tube  sized and
shaped to fit within and engage a human or animal body cavity  the tube comprising an inner surface defining an enclosed region and an outer surface that turns outward to engage the body cavity and turns inward to encompass a central region defining a concentric longitudinal path  wherein the tube is
25 powerable to provide relative movement of the tube relative to the cavity in at least one of a forward or reverse direction with respect to the longitudinal path; and a compressible structure  configured to bias the outer surface of the tube outward to engage the body cavity at a first outer diameter  the compressible structure being deformable inward in response to a compressive force to provide
30 a second outer diameter that is less than the first outer diameter.
In Example 2  the apparatus of Example 1 is optionally configured such that the compressible structure includes a foam material located within the enclosed region.
In Example 3  the apparatus of at least one of Examples 1 or 2 is optionally configured such that the compressible structure includes at least one bowed member located within the enclosed region.
In Example 4  the apparatus of at least one of Examples 1-3 is optionally 5 configured such that the compressible structure includes at least one bowed strut member located within the enclosed region.
In Example 5  the apparatus of at least one of Examples 1-4 is optionally configured such that the compressible structure includes at least one spring- loaded linked strut located within the enclosed region.
10 In Example 6  the apparatus of at least one of Examples 1-5 optionally
further comprises a frame including a support structure located within the enclosed region and a housing structure located within a central cavity of the self-enclosed tube.
In Example 7  the apparatus of Example 6 is optionally configured such 15 that the compressible structure includes a foam material attached to the support structure.
In Example 8  a apparatus comprises a self-enclosed toroidal tube  sized and shaped to fit within and engage a human or animal body cavity  the tube comprising a flexible material having an inner surface defining an enclosed
20 region and an outer surface that turns outward to engage the body cavity and turns inward to encompass a central region defining a concentric longitudinal path; an attachment coupled to the tube  the attachment to secure a payload  wherein the tube is powerable to provide relative movement of the tube relative to the cavity  and to thereby help to move the payload with respect to the cavity 
25 in at least one of a forward or reverse direction with respect to the longitudinal path; a frame including a drive support structure located within the enclosed region and a housing structure located within a central cavity of the self-enclosed tube; and a compressible support structure coupled to the drive support structure and configured to bias the outer surface of the tube outward to engage the body
30 cavity at a first outer diameter  the compressible structure being deformable inward in resprinse tca cnmpressivP ffNrcP trN PrrWirl e SPCINnd nil ter diameter that is less than the first outer diameter.
In Example 9  the apparatus of Example 8 is optionally configured such
that the compressible structure includes a foam material located within the enclosed region between the support structure and the flexible material.
In Example 10  the apparatus of Example 9 is optionally configured such that the foam material includes a plurality of foam strips longitudinally
5 extending along an outer surface of the support structure.
In Example 11  the apparatus of at least one of Examples 8-10 is optionally configured such that the compressible structure includes a plurality of bowed members located within the enclosed region.
In Example 12  the apparatus of at least one of Examples 8-11 is
10 optionally configured such that the compressible structure includes a plurality of bowed strut members located within the enclosed region.
In Example 13  the apparatus of at least one of Examples 8-12 is optionally configured such that the compressible structure includes a plurality of spring-loaded linked struts located within the enclosed region.
15 In Example 14  a method comprises deploying a propellable self-
enclosed tube within a cavity; decreasing a diameter of the self-enclosed tube to
a first diameter when a compressive force occurs within the cavity; and passively expanding the diameter of the self-enclosed tube to a second diameter  larger than the first diameter  when the compressive force is passed.
20 In Example 15  the method of Example 14 is optionally configured such
that decreasing a diameter and passively expanding the diameter include providing a compressible structure within the self-enclosed tube  the compressible structure being configured to bias an outer surface of the tube outward to engage a wall of the cavity at the second diameter  the compressible
25 structure being deformable inward in response to the compressive force to
provide the first diameter.
In Example 16  the method of Example 15 is optionally configured such that the compressible structure includes a foam material.
In Example 17  the method of at least one of Examples 15 or 16 is
30 optionally configured such that the compressible structure includes at least one bowed member 
In Example 18  the method of at least one of Examples 15-17 is
optionally configured such that the compressible structure includes at least one
bowed strut member.
In Example 19  the method of at least one of Examples 15-18 is optionally configured such that the compressible structure includes at least one spring-loaded linked strut.
5 In Example 20  the method of at least one of Examples 14-19 further
comprises securing a payload to the self-enclosed tube for transport within the cavity.
In Example 21  use of a compressible structure in the manufacture of an apparatus  including a self-enclosed tube  for the treatment or diagnosis of a
10 small bowel or colon disorder is described. The self-enclosed tube includes an outer surface that turns outward to engage a wall of the small bowel or colon; and the compressible structure is configured to bias the outer surface of the self- enclosed tube outward to engage the wall of the small bowel or colon at a first outer diameter and is configured to deform inward in response to a compressive
15 force to provide a second outer diameter that is less than the first outer diameter.
In Example 22  the use of Example 21 is optionally configured such that the compressible structure includes a foam material located within the self- enclosed tube.
In Example 23  the use of at least one of Examples 21 or 22 is optionally 20 configured such that the compressible structure includes at least one bowed member located within the self-enclosed tube.
In Example 24  the use of at least one of Examples 21-23 is optionally configured such that the compressible structure includes at least one bowed strut member located within the self-enclosed tube.
25 In Example 25  the use of at least one of Examples 21-24 is optionally
configured such that compressible structure includes at least one spring-loaded linked strut located within the self-enclosed tube.
In Example 26  the use of any of claims 21-25 optionally comprises use of a frame including a support structure located within the self-enclosed tube in
30 the manufacture of the apparatus for the treatment or diagnosis of the small bowel or colon disorder.
This Overview is intended to provide non-limiting examples of subject matter described in the present patent document. It is not intended to provide an
exclusive or exhaustive explanation of the invention. The Detailed Description is included to provide further information about the present patent document.
BRIEF DESCRIPTION OF THE DRAWINGS
5 FIG. 1 shows an example of a propellable apparatus  in
accordance with one embodiment.
FIG. 2A shows a propellable apparatus within a body cavity  in
accordance with one embodiment.
FIG. 2B shows the propellable apparatus of FIG. 2A within the
10 body cavity  in accordance with one embodiment.
FIG. 2C shows the propellable apparatus of FIG. 2A within the
body cavity  in accordance with one embodiment.
FIG. 3A shows a cross-section of a propellable apparatus  in
accordance with one embodiment.
15 FIG. 3B shows a cross-section of a propellable apparatus  in
accordance with one embodiment.
FIG. 3C shows a cross-section of a propellable apparatus  in
accordance with one embodiment.
FIG. 3D shows a cross-section of a propellable apparatus  in
20 accordance with one embodiment.
FIG. 4A shows an example of a compressible structure  in
accordance with one embodiment.
FIG. 4B shows an example of a compressible structure  in
accordance with one embodiment.
25 FIG. 5 shows another example of a compressible structure  in
accordance with one embodiment.
FIG. 6 shows another example of the compressible structure of
FIG. 5  in accordance with one embodiment.
FIG. 7 shows another example of a compressible structure  in
30 accordance with one embodiment.
DETAILED DESCRIPTION
A self-enclosed toroidal membrane can be used to create a propulsive force  such as between a propellable apparatus and the wall of the body cavity or lumen. The propellable apparatus can be used to help advance or maneuver an
5 endoscope or other accessory  such as within the body cavity or lumen.
FIG. 1 shows a sectional view of an example of a propellable apparatus 200 that includes a toroidal self-enclosed tube 204. The self-enclosed tube 204 can be driven within the internal structure of the apparatus such as to create a propulsive force as its outer surface moves relative to the tissue wall 250. Self-
10 enclosed tube 204 is generally toroidal or ring shaped. Self-enclosed tube 204
includes a flexible material 206. Flexible material 206 of self-enclosed tube 204 has an interior surface 220 and an exterior surface 222. Interior surface 220 of flexible material 206 defines an interior volume or enclosed region 224. Exterior surface 222 of flexible material 206 defines a central cavity 226.
15 The apparatus 200 also includes a frame 208. Frame 208 both supports
and interacts with the flexible material 206 of the self-enclosed tube 204. Frame 208 includes a drive support structure 228 and a housing structure 230. Housing structure 230 is disposed in central cavity 226 defined by exterior surface 222 of flexible material 206 of self-enclosed tube 204. Drive support structure 228 is
20 disposed within enclosed region 224 defined by interior surface 220 of flexible material 206 of self-enclosed tube 204.
In this example  drive support structure 228 and housing structure 230 each rotatably support a plurality of rollers. For example  a plurality of motive rollers 234 are shown contacting flexible material 206 of self-enclosed tube 204.
25 Rotation of motive rollers 234 is capable of causing flexible material 206 to move relative to the rotational axis of each motive roller 234.
A worm gear 244 includes a first thread 242 and a second thread 243.
The teeth 240 of a first set of motive roller 234 are shown mating with first
thread 242 of worm gear 244. Accordingly  rotation of worm gear 244 will 30 cause the first set of motive rollers 234 to rotate.
Housing structure 230 rotatably supports a plurality of stabilizing rollers 236. Each stabilizing roller 236 contacts the exterior surface 222 of flexible material 206 of self-enclosed tube 204. A plurality of suspended stabilizing
rollers 238 are located proximate each stabilizing roller 236 and supported by spring-loaded supports 229 of drive support structure 228. Each suspended stabilizing roller 238 contacts interior surface 220 of flexible material 206 of self-enclosed tube 204. In some embodiments  suspended stabilizing roller 238
5 acts to bias exterior surface 222 of flexible material 206 against a stabilizing
roller 236.
A suspended motive roller 232 is disposed proximate each motive roller 234. Each suspended motive roller 232 can be pivotally supported by drive support structure 228. In some embodiments  drive support structure 228 and
10 suspended motive rollers 232 act to bias exterior surface 222 of flexible material 206 against motive rollers 234.
Various embodiments of housing structure 230 and drive support structure 228 are possible. One embodiment may be viewed as two tubes positioned with one inside the other. The outer tube being the drive support
15 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  either the drive 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.
20 The flexible material 206 of the self-enclosed tube 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 self- enclosed tube 204 to pass between the support and housing structures even if the
25 material folds over itself or is bunched up.
The present inventors have recognized that it is beneficial to creating a propulsive force for the outer surface of the flexible material 204 to be in close proximity to the tissue wall 250. In the case of a body cavity or body lumen  such as for example  the colon or small bowel  the present inventors have
30 recognized that this propulsive force can increase as the diameter of the outer
surface of the flexible material increases relative to the circumference of the
body lumen. This increase in propulsive force may be driven by greater area of
surface contact between the tissue wall 250 and the rotating toroidal surface of the device.
The propulsive force may also be increased due to increased contact pressure between these surfaces brought about by the increased diameter of the
5 device. However  the present inventors have also recognized that having this relatively larger diameter for increasing propulsive force is at odds with a need to have as small a diameter as possible for introducing the apparatus (which can optionally be accompanied by an endoscope or other accessory) into the body lumen. Examples of orifices for introducing the endoscope and apparatus
10 include the anal sphincter  or through the mouth and esophageal sphincter. In addition to these orifices and reduced-diameter sphincters  there can be other points of reduced lumen diameter  such as for example the iliocecal orifice between the small bowel and colon  or strictures in any of the body lumens such as brought on by scar tissue or growths such as cancers or polyps. These points
15 of reduced diameter generally cannot accept introduction of rigid devices having diameters equal to the diameters of the internal lumens adjacent them without risk of injury or discomfort. The present inventors have also recognized that it will sometimes be desirable to have the device diameter variable such as to accommodate its extended use in one or more lumens of different diameters. An
20 example of this would be for a device that is used to propel a scope in a retrograde approach through the colon and into the small bowel. The colon typically has a diameter that can be 50-100% greater than a diameter of the small bowel. It would be beneficial if the propulsive device can effectively propel the scope through the larger diameter colon and then on into the smaller diameter
25 small bowel.
The present inventors have recognized that it is therefore desirable to have the outer diameter of the device that is configured to be variable  such as to allow a smaller diameter when passing through points or regions of reduced diameter  and to allow a larger drive diameter in larger diameter regions of the
30 anatomy. The present inventors have also recognized that it is also desirable for this size transition to occur without the need for active actuation on the part of the operator. This is because it does not require an additional step in the procedure (and additional complexity of the device). This is also because these
locations of reduced diameter may be unpredictable  for example  in where they are located  or in their degree of constriction.
One approach to providing some variability in diameter would be to use air or another compressible gas to inflate the flexible material. However  this
5 approach may be limited in the range of diameters achievable because of the gas inflation pressure that would be needed. Other approaches to providing some variability can require operator actuation  which may be difficult  for example  to repeatedly actuate multiple times or to multiple different diameters using the same propulsion device during the same medical procedure.
10 By contrast  the present patent document describes  among other things  a
variety of examples of one or more compressible structures such as can be used to help fill the volume of the diameter between (1) the outer diameter of the rigid drive mechanism that drives the toroidal flexible material; and (2) the desired outer diameter of the toroidal flexible material that provides propulsion in the
15 body lumen. These compressible structures provide some at least partially solid structure beyond just pressurized gas used to inflate the toroidal flexible material  although the compressible structures can  in some examples  be used in combination with a pressurized gas that acts to expand the diameter of the toroidal surface.
20 An illustrative example is shown in FIGS. 2A-2C  which show a
propellable apparatus 200 within a body cavity 272  in accordance with one embodiment. Apparatus 200 includes a toroidal self-enclosed tube 204  which can be driven by a drive mechanism as discussed above  along with a drive cable 274. In this example  the apparatus 200 carries an endoscope or other accessory
25 276 within the body cavity.
Apparatus 200 includes a compressible structure configured to compress to a smaller diameter  when the device passes through a sphincter or other region of reduced diameter 280  such as shown in the example of FIG. 2B.
The apparatus 200 and compressible structure can then expand back out 30 to its original diameter after passing through the region of reduced diameter 280 
such as shown in the example of FIG_
In some examples  one or more of these compressible structures can be mounted to the outer surface of the hard drive mechanism  such that the flexible
10
material 206 then slides over their outer surface(s) when the device drive is engaged to drive the flexible material.
FIG. 3A shows a cross-section of a propellable apparatus 300 carrying an endoscope or other accessory 301  in accordance with one embodiment. In this
5 example  the compressible structure includes a cellular or other foam material 310 that can be attached to the outer surface 303 of the rigid drive support structure 228 and is located within the enclosed region 302 of the propellable apparatus 300 between the outer surface 303 of the rigid drive support structure 228 and the outer surface of the flexible material 206 of the self-enclosed tube
10 204.
In one example in which the propellable apparatus is a device designed for use over an 11 millimeter diameter colonoscope  the rigid incompressible drive structure can have an outer diameter of about 22 millimeters. In this illustrative example  the foam then can be adhered to the outer surface of the
15 rigid drive structure to yield an effective uncompressed outer diameter of the foam of about 33 millimeters. This foam can include a contiguous annular band of foam covering the whole outer surface of the drive structure and providing a somewhat cylindrical-like outer foam diameter  such as shown in the example of FIG. 3A. An example of a possible foam that can be used for this is Z60-I
20 reticulated polyurethane foam  which is produced by Foamex International  of Linwood  PA. In this example  the toroidal flexible material then traverses through the internal drive structure and wraps over the outer surface of the foam. In some examples  such foam compressible structure construction allows a 33 millimeter drive diameter  while compressing down to a diameter of 25
25 millimeters or less when passing through regions of reduced diameter.
FIGS. 3B-3D show cross-sections of other illustrative examples  in accordance with one or more embodiments. In these examples  a foam material on top of the drive structure can be configured in strips such as to only cover a fraction of the surface area while still similarly supporting the flexible material
30 at an expanded outer diameter. Eliminating some of the mass of foam in this way can decrease the force needed to compress the foam to a smaller diameter as compared to the fully annular foam covering described above with respect to FIG. 3A.
11
For example  FIG. 3B shows a plurality of foam strips 320 attached longitudinally along the outer surface 303 of the rigid drive support structure 228 and located between the support structure and the outer surface of flexible material 206.
5 In FIG. 3C  the foam structure 330 includes a plurality of holes or spaces
322.
In FIG. 3D  the foam structure 340 includes a series of foam arches encircling the outer surface of the rigid drive support structure 228.
In the examples above  the thickness of the foam  the stiffness of the
10 foam  and the percent area of the outer surface of the drive structure that is covered with foam can all be varied  such as to strike a desired balance between the desired compressed diameter for passing through a restricted diameter  the desired compressive force for compressing the foam  and the desired expansive force of the foam for providing the propulsive force at the toroidal flexible
15 material when the foam is in a partially or fully expanded state within the body lumen. The diameters cited above are provided by way of illustrative example  and not by way of limitation. Other sizes of endoscopes or other accessories  and other diameters of the rigid drive structure of a propellable apparatus can be used as desired  such as for different anatomies  while still using and benefiting
20 from a passively expandable and passively compressible structure that does not require user or other actuation to conform to different anatomical sizes in use.
FIGS. 4A and 4B show an example of a compressible structure 402  in accordance with one embodiment. In this example  the compressible structure includes multiple bowed elements 404. A bowed element 404 can be connected
25 to the outer surface of the drive support structure 228 at one end 406. At the other end  the bowed element 404 can be connected to the outer surface of the drive support structure 228 using a slide track mechanism 408. In some examples  the bowed elements 404 can be used to act as leaf springs  which are bowed out to support the flexible material of the self-enclosed tube  but which
30 are able to compress as the one end moves along the slide track 408 when an
external compressive force on the flexible material increases. In some examples 
these bowed elements 404 can be made of stainless steel  nitinol  or one or more of any number of engineering polymers. The non-sliding connection 406 of the
12
bowed element 404 to the outer surface of the drive support structure 228 can include a pinned connection. This can allow rotation of that end of the bowed element 404 as the other end moves in the slide 408 on the other end when the bowed element 404 is compressed down towards the outer surface of the drive
5 support structure 228.
As shown in FIG. 4B  bowed elements 404 can be arranged on the outer surface of the drive support structure 228 to provide an overall compressible structure for a propellable apparatus.
FIGS. 5 and 6 show another example of a compressible structure  in
10 accordance with one embodiment. In this example  the compressible structure includes multiple bowed strut elements 502 supporting the flexible material 206 of self-enclosed tube 204. The ends of the elements 502 can be attached at or near opposite ends of the drive support structure 228. These connections can be fixed  pinned (such as to allow rotation)  or in respective slide track mechanisms
15 (such as to allow a degree of axial movement).
In this example  the regions of maximum strain upon the bowed elements 502 when compressed to a reduced diameter state can be located longitudinally outward from the ends of the cylindrical-like rigid drive structure rather than radially outward from its cylindrical-like circumference. This can permit more
20 space for the deformation of the bowed elements  because the space taken up by the drive support structure 228 over the endoscope or other accessory is available for flexing and attached portions of the bowed elements in front of or behind the ends of the cylindrical-like drive structure  such as shown in FIG. 6.
FIG. 7 shows another example of a compressible structure  in accordance
25 with one embodiment. In this example  the compressible structure can include multiple linkages of struts 702. Such linkages 702 can be spring loaded 704 such as at the anchor points at the drive support structure 228. This can permit the linkages 702 to support the toroidal flexible material 206 at its larger diameter  and to collapse down to a reduced diameter with increased
30 compressive force on the toroidal flexible material 206. In some examples  the struts 702 making up a linkage can be made of stainless steel wires or members  such as with holes on the ends such as to enable pinning the struts together at the joints of the linkage.
13
These disclosed examples show a number of possible structures that can achieve  without requiring user-actuation  a desired variable toroidal flexible material diameter for the propellable apparatus  which can be used to propel or maneuver an endoscope or other accessory. Other materials or variations of
5 these examples can be used  such as to achieve a similar desired variable diameter  which can benefit the performance of the propulsion system.
Additional Notes:
The above Detailed Description includes references to the accompanying
10 drawings  which form a part of the Detailed Description. The drawings show  by way of illustration  specific embodiments in which the invention can be practiced. These embodiments are also referred to herein as "examples." Such examples can include elements in addition to those shown and described. However  the present inventors also contemplate examples in which only those
15 elements shown and described are provided.
All publications  patents  and patent documents referred to in this document are incorporated by reference herein in their entirety  as though individually incorporated by reference. In the event of inconsistent usages between this document and those documents so incorporated by reference  the
20 usage in the incorporated reference(s) should be considered supplementary to that of this document; for irreconcilable inconsistencies  the usage in this document controls.
In this document  the terms "a" or "an" are used  as is common in patent documents  to include one or more than one  independent of any other instances
25 or usages of "at least one" or "one or more." In this document  the term "or" is used to refer to a nonexclusive or  such that "A or B" includes "A but not B " "B but not A " and "A and B " unless otherwise indicated. In the appended claims  the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein." Also  in the following
30 claims  the terms "including" and "comprising" are open-ended  that is  a system  device  article  or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover  in the following claims  the terms "first " "second " and
14
"third " etc. are used merely as labels  and are not intended to impose numerical requirements on their objects.
The above description is intended to be illustrative  and not restrictive. For example  the above-described examples (or one or more aspects thereof)
5 may be used in combination with each other. Other embodiments can be used  such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to comply with 37 C.F.R. § 1.72(b)  to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or
10 meaning of the claims. Also  in the above Detailed Description  various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather  inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus  the following claims are hereby
15 incorporated into the Detailed Description  with each claim standing on its own
as a separate embodiment. The scope of the invention should be determined with reference to the appended claims  along with the full scope of equivalents to which such claims are entitled.
WHAT IS CLAIMED IS:
1. An apparatus comprising:
a self-enclosed tube  sized and shaped to fit within and engage a human or
5 animal body cavity  the tube comprising an inner surface defining an enclosed region and an outer surface that turns outward to engage the body cavity and turns inward to encompass a central region defining a concentric longitudinal path  wherein the tube is powerable to provide relative movement of the tube relative to the cavity in at least one of a forward or reverse direction with respect to the
10 longitudinal path; and
a compressible structure  configured to bias the outer surface of the tube outward to engage the body cavity at a first outer diameter  the compressible structure being deformable inward in response to a compressive force to provide a second outer diameter that is less than the first outer diameter.
15
2. The apparatus of claim 1  wherein the compressible structure includes a
foam material located within the enclosed region.
3. The apparatus of any of claims 1 or 2  wherein the compressible structure
20 includes at least one bowed member located within the enclosed region.
4. The apparatus of any of claims 1-3  wherein the compressible structure
includes at least one bowed strut member located within the enclosed region.
25 5. The apparatus of any of claims 1-4  wherein the compressible structure
includes at least one spring-loaded linked strut located within the enclosed region.
6. The apparatus of any of claims 1-5  further including a frame comprising a
support structure located within the enclosed region and a housing structure located 30 within a central cavity of the self-enclosed tube.
16
7. The apparatus of claim 6  wherein the compressible structure includes a
foam material attached to the support structure.
8. An apparatus comprising:
5 a self-enclosed toroidal tube  sized and shaped to fit within and engage a
human or animal body cavity  the tube comprising a flexible material having an inner surface defining an enclosed region and an outer surface that turns outward to engage the body cavity and turns inward to encompass a central region defining a concentric longitudinal path;
10 an attachment coupled to the tube  the attachment to secure a payload 
wherein the tube is powerable to provide relative movement of the tube relative to the cavity  and to thereby help to move the payload with respect to the cavity  in at least one of a forward or reverse direction with respect to the longitudinal path;
a frame including a drive support structure located within the enclosed
15 region and a housing structure located within a central cavity of the self-enclosed tube; and
a compressible support structure coupled to the drive support structure and configured to bias the outer surface of the tube outward to engage the body cavity at a first outer diameter  the compressible structure being deformable inward in
20 response to a compressive force to provide a second outer diameter that is less than the first outer diameter.
9. The apparatus of claim 8  wherein the compressible structure includes a
foam material located within the enclosed region between the support structure and
25 the flexible material.
10. The apparatus of claim 9  wherein the foam material includes a plurality of
foam strips longitudinally extending along an outer surface of the support structure.
30
17
11. The apparatus of any of claims 8-10  wherein the compressible structure
includes a plurality of bowed members located within the enclosed region.
12. The apparatus of any of claims 8-11  wherein the compressible structure
5 includes a plurality of bowed strut members located within the enclosed region.
13. The apparatus of any of claims 8-12  wherein the compressible structure
includes a plurality of spring-loaded linked struts located within the enclosed region.
10 14. A method comprising:
deploying a propellable self-enclosed tube within a cavity;
decreasing a diameter of the self-enclosed tube to a first diameter when a compressive force occurs within the cavity; and
passively expanding the diameter of the self-enclosed tube to a second 15 diameter  larger than the first diameter  when the compressive force is passed.
15. The method of claim 14  wherein decreasing a diameter and passively
expanding the diameter include providing a compressible structure within the self- enclosed tube  the compressible structure being configured to bias an outer surface
20 of the tube outward to engage a wall of the cavity at the second diameter  the compressible structure being deformable inward in response to the compressive force to provide the first diameter.
16. The method of claim 15  wherein the compressible structure includes a foam
25 material.
17. The method of any of claims 15 or 16  wherein the compressible structure
includes at least one bowed member.
30
18
18. The method of any of claims 15-17  wherein the compressible structure
includes at least one bowed strut member.
19. The method of any of claims 15-18  wherein the compressible structure
5 includes at least one spring-loaded linked strut.
20. The method of any of claims 14-19  further including securing a payload to
the self-enclosed tube for transport within the cavity.
10 21. Use of a compressible structure in the manufacture of an apparatus 
including a self-enclosed tube  for the treatment or diagnosis of a small bowel or colon disorder;
wherein the self-enclosed tube includes an outer surface that turns outward to engage a wall of the small bowel or colon; and
15 wherein the compressible structure is configured to bias the outer surface of
the self-enclosed tube outward to engage the wall of the small bowel or colon at a first outer diameter and is configured to deform inward in response to a compressive force to provide a second outer diameter that is less than the first outer diameter.
20 22. The use of claim 21  wherein the compressible structure includes a foam
material located within the self-enclosed tube.
23. The use of any of claims 21 or 22  wherein the compressible structure
includes at least one bowed member located within the self-enclosed tube.
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24. The use of any of claims 21-23  wherein the compressible structure includes
at least one bowed strut member located within the self-enclosed tube.
25. The use of any of claims 21-24  wherein the compressible structure includes
30 at least one spring-loaded linked strut located within the self-enclosed tube.
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26. The use of any of claims 21-25  comprising use of a frame including a
support structure located within the self-enclosed tube in the manufacture of the apparatus for the treatment or diagnosis of the small bowel or colon disorder.
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ABSTRACT
An apparatus includes a self-enclosed tube  sized and shaped to fit within
and engage a human or animal body cavity  the tube comprising an inner surface defining an enclosed region and an outer surface that turns outward to engage the
5 body cavity and turns inward to encompass a central region defining a concentric longitudinal path  wherein the tube is powerable to provide relative""movement of the tube relative to the cavity in at least one of a forward or reverse direction with respect to the longitudinal path  and a compressible structure  configured to bias the outer surface of the tube outward to engage the body cavity at a first outer diameter 
10 the compressible structure being deformable inward in response to a compressive force to provide a second outer diameter that is less than the first outer diameter.
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