Floating gastrointestinal anchor
Apparatus is provided for use in a stomach of a subject. The apparatus includes a gastric balloon and an anchor coupled to the gastric balloon. The anchor includes a flexible tube, which, when in a relaxed position, is shaped so as to define a portion that prevents the anchor from passing into a duodenum of the subject. The anchor also includes one or more shape-controlling elements coupled to the portion and configured to control a shape of the portion. Other embodiments are also described.
1. Apparatus for use in a stomach of a subject, the apparatus comprising a gastric balloon and an anchor coupled to the gastric balloon, the anchor comprising:
a flexible tube, which, when in a relaxed position, is shaped so as to define a portion that prevents the anchor from passing into a duodenum of the subject;
one or more shape-controlling elements coupled to the portion and configured to control a shape of the portion; and
wherein the one or more shape-controlling elements comprise one or more cross-bar elements which cross the portion of the flexible tube that prevents the anchor from passing into the duodenum, and which are configured to help maintain the shape of the portion.
2. The apparatus according to claim 1 , wherein the one or more shape-controlling elements comprise one or more bend-limiting elements configured to limit excess bending of the portion.
3. The apparatus according to claim 2 , wherein the one or more bend-limiting elements comprise a plurality of mechanical elements that are disposed in series, wherein the plurality of mechanical elements comprise mechanical elements selected from the group consisting of: a plurality of mechanical elements that are chained to one another and a plurality of mechanical elements that are free from one another.
4. The apparatus according to claim 2 , wherein the one or more bend-limiting elements are arranged in a chain.
5. The apparatus according to claim 2 , wherein the one or more bend-limiting elements comprise a bend-limiting tube shaped so as to define a plurality of slits which permit limited back and forth flexing of the bend-limiting tube.
6. The apparatus according to claim 1 , wherein the one or more shape-controlling elements run along the portion of the flexible tube.
7. The apparatus according to claim 1 , wherein the anchor is configured, when stretched, to assume an elongated position in which the tube is generally straight, and in which the cross-bar functionality is positioned approximately parallel with the tube.
8. The apparatus according to claim 1 , wherein the one or more cross-bar elements comprise at least two cross-bar elements.
9. The apparatus according to claim 1 , wherein the portion of the flexible tube that prevents the anchor from passing into the duodenum is generally planar.
10. The apparatus according to claim 9 , wherein the flexible tube comprises an additional portion that projects away from a plane defined by the planar portion and wherein the gastric balloon is coupled to the additional portion of the flexible tube.
11. The apparatus according to claim 9 , wherein the portion is generally circular.
12. The apparatus according to claim 1 , wherein the anchor is configured, when stretched, to assume an elongated position in which the tube is generally straight, and in which the one or more shape-controlling elements are positioned approximately parallel with the tube.
13. The apparatus according to claim 1 , wherein the gastric balloon comprises a 400-1000 cc balloon.
14. The apparatus according to claim 1 , wherein the anchor is configured to be positioned in an antrum of the stomach such that the anchor to some extent interferes with natural antral contractions of the antrum.