Patent ID: 8202291

Claim:
An intragastric balloon, comprising: an initial fill gas consisting essentially of N 2 as an inert gas and CO 2 ; a polymeric wall having, under conditions of an in vivo gastric environment, a permeability to CO 2 of more than 10 cc/m 2 /day, such that a rate and an amount of diffusion of CO 2 from the in vivo gastric environment into a lumen of the balloon through the polymeric wall is controlled, at least in part, by a concentration of N 2 and a concentration of CO 2 in the initial fill gas, wherein the concentration of CO 2 in the initial fill gas is similar to gastric pCO 2 ; and a valve system configured for introducing the initial fill gas into the lumen of the balloon in the in vivo gastric environment, wherein the intragastric balloon is configured to have a useful life in an in vivo gastric environment of at least 30 days.