Endoscopic sleeve

1. A device comprising:

an endoscopic sleeve comprising a tubular member from which extend a plurality of spaced projecting elements, each of which has an initial position, said projecting elements being bendable towards both proximal and distal directions of said tubular member, wherein a force (insertion force) required to bend said projecting elements from said initial positions towards the proximal direction is less than a force (extraction force) required to bend said projecting elements from said initial positions towards the distal direction and a distance all around an outer periphery of said projecting elements decreases as the extraction force increases, and wherein said projecting elements comprise sets of projecting elements, each set spaced axially from one another, and wherein adjacent sets of projecting elements comprise a more proximal set of projecting elements and a more distal set of projecting elements, and the more proximal set of projecting elements is hindered in bending towards said distal direction by abutting against the more distal set of projecting elements.

2. The device according to claim 1 , wherein said projecting elements are more easily bendable towards the proximal direction than towards the distal direction.

3. The device according to claim 1 , wherein each of said projecting elements comprises a root portion that extends from said tubular member and a tissue interface portion that extends outwards from said root portion, wherein said root portion is thinner than said tissue interface portion and is offset proximally from a centerline of said tissue interface portion, and wherein bending of said projecting elements towards the proximal direction is not hindered and bending of said projecting elements towards the distal direction is hindered by said tissue interface portion abutting against said tubular member.

4. The device according to claim 1 , wherein said projecting elements comprise at least partial rings.

5. The device according to claim 1 , wherein said projecting elements comprise discrete wings spaced from one another by gaps about a periphery of said tubular member.

6. The device according to claim 1 , wherein gaps of one set of said projecting elements are angularly offset in a circumferential direction from gaps of an adjacent set of projecting elements.

7. The device according to claim 1 , wherein the more proximal set of projecting elements comprises an abutting portion arranged to abut against the more distal set of projecting elements, said abutting portion being wider than the gap between the projecting elements of the more distal set of projecting elements.

8. The device according to claim 1 , wherein said projecting elements have a thicker base joining said tubular member which tapers in a direction away from said tubular member.

9. The device according to claim 1 , wherein progressing proximally along a length of said tubular member, said sets of projecting elements are gradually larger in a radial direction extending out from said tubular member.

10. The device according to claim 1 , wherein seals are placed at distal and proximal portions of said tubular member.

11. The device according to claim 1 , wherein said tubular member comprise elongate, longitudinal stiffening ribs.

12. The device according to claim 1 , wherein a web is formed between two of said protruding elements.

13. A method of improving endoscopic visualization comprising installing the endoscopic sleeve of claim 1 on an endoscope and inserting the endoscope in a body lumen, wherein during distal motion of the endoscope in the body lumen said projecting elements bend towards the proximal direction so as not to hinder the distal motion of the endoscope, and during proximal motion of the endoscope in the body lumen said projecting elements sufficiently project away from said tubular member so as to engage and unfold tissue folds in said body lumen for improved endoscopic visualization of said folds.