Intragastric device

1. An intragastric balloon comprising:

an initial fill gas, wherein the initial fill gas consists essentially of one or more gases selected from the group consisting of SF 6 , C 2 F 6 , C 3 F 8 , C 4 F 10 , C 3 F 6 , CF 4 , and C(ClF 2 )—CF 3 ;

a valve system configured for introducing the initial fill gas into the balloon in vivo; and

a polymeric wall comprising one or more layers, wherein the polymeric wall is configured to have, under in vivo conditions, a permeability to CO 2 of more than 10 cc/m 2 /day, and wherein the polymeric wall is configured such that, in vivo, the balloon is configured to gain in volume and in pressure during a useful life of the intragastric balloon when filled with the initial fill gas, wherein the intragastric balloon when inflated with the initial fill gas is ellipsoid with a nominal radius of from 2.5 cm to 7.6 cm, a nominal height of from 0.6 cm to 7.6 cm, a volume of from 90 cm 3 to 350 cm 3 at 37° C., an internal nominal pressure at 37° C. of 0 Pa to 103421 Pa, and a weight of less than 15 g.

2. The intragastric balloon of claim 1 , wherein the polymeric wall comprises a three layer CO 2 barrier material consisting of nylon/polyvinylidene chloride/polyethylene.

3. The intragastric balloon of claim 1 , wherein the polymeric wall comprises a three layer CO 2 barrier material consisting of nylon/ethylene vinyl alcohol/polyethylene.

4. The intragastric balloon of claim 1 , wherein the polymeric wall comprises a two layer CO 2 barrier material consisting of nylon/polyethylene and no additional CO 2 barrier material.

5. The intragastric balloon of claim 1 , wherein the polymeric wall comprises a four layer CO 2 barrier material consisting of nylon/ethylene vinyl alcohol/polyvinylchloride/polyethylene.

6. The intragastric balloon of claim 1 , wherein the polymeric wall comprises a nylon layer, a polyvinylidene chloride layer, and a polyethylene layer.

7. The intragastric balloon of claim 1 , wherein the polymeric wall comprises a nylon layer, a polyvinylidene chloride layer, a polyethylene layer, and an ethylene vinyl alcohol layer.

8. The intragastric balloon of claim 1 , wherein the polymeric wall comprises a nylon layer, a polyethylene layer, and an ethylene vinyl alcohol layer.

9. The intragastric balloon of claim 1 , wherein the intragastric balloon is configured to have a useful life in an in vivo gastric environment of at least 6 months.

10. A method for inflating an intragastric balloon, comprising:

providing an intragastric balloon comprising a valve system and a polymeric wall, wherein the polymeric wall comprises one or more layers, and wherein the polymeric wall is configured to have, under in vivo conditions, a permeability to CO 2 of more than 10 cc/m 2 /day;

introducing, in an in vivo intragastric environment, an initial fill gas into the intragastric balloon through the valve system so as to fill the intragastric balloon, wherein the filled balloon is ellipsoid with a nominal radius of from 2.5 cm to 7.6 cm, a nominal height of from 0.6 cm to 7.6 cm, an initial volume of from 90 cm 3 to 350 cm 3 at 37° C., an internal nominal pressure at 37° C. of 0 Pa to 103421 Pa, and a weight of less than 15 g, wherein the initial fill gas consists essentially of one or more gases selected from the group consisting of SF 6 , C 2 F 6 , C 3 F 8 , C 4 F 10 , C 4 F 8 , C 3 F 6 , CF 4 , and C(ClF 2 )—CF 3 ; and

exposing the filled balloon to the in vivo intragastric environment for a useful life of the intragastric balloon, whereby the initial fill gas diffuses through the polymeric wall and into the in vivo intragastric environment, and whereby gases in the in vivo intragastric environment diffuse into the balloon through the wall, whereby the intragastric balloon gains in volume and in pressure over the useful life.

11. The intragastric balloon of claim 1 , wherein the initial fill gas is SF 6 .

12. The method of claim 10 , wherein the initial fill gas is SF 6 .