Abstract: A bariatric balloon having a gas-filled antral chamber of a flexible sheet material, the antral chamber having an elastic superior wall joined peripherally with a less-elastic annular wall, the annular wall further joined peripherally with a non-elastic inferior wall, the inferior wall of a more rigid character than the superior wall and the annular wall. The superior wall has a convex shape, the annular wall has a cylindrical shape, and the inferior wall has a planar shape. Secured below the antral chamber, a gas filled pyloric chamber joined to, and contiguous with, the antral chamber, a pyloric wall encompasses the cyloric chamber. The gas-filled antral and pyloric chambers define a volume less than the volume of a human stomach. Safety arms are mounted on a gas inlet/outlet valve and extend radially from the valve in order to prevent the deflated balloon from passing through the pyloric sphincter.

Abstract: A gastric bariatric balloon includes an upper balloon chamber for sealing against the fundus, a lower balloon chamber for sealing against the antrum and occupying the body of the stomach, and a supplementary chamber for filling at least a portion of the fundus. A tubular inlet is proximal the esophagus entry for receiving a hollow needle. This inlet is filled with a self-sealing material so that when punctured by the needle the material closes the needle hole upon withdrawal of the needle. Spaced apart voids in the material enable fluid interchange between the needle and each of the three chambers separately depending upon the depth of the needle within the inlet tube. Safety arms are mounted on the upper balloon chamber so as to prevent passage of the balloon through the pylorus in case of sudden deflation.