The medical systems, apparatuses and uses thereof for treating obesity and/or obesity-related diseases are provided which relate to devices designed to stimulate an internal surface of the stomach such as the cardia. Features of the obesity treatment devices include insertion of said devices transorally and without invasive surgery, without associated patient risks of invasive surgery, and without substantial patient discomfort. The devices include flotation portions and cardia-stimulating portions, so that as the level of stomach contents rise, the devices will contact and stimulate the nerves in the cardia region of the stomach to induce satiety. The devices may have non-inflatable balls, be made of skinned foam, have ballast members such as a weighted ball or quantity of saline for orientation, and various combinations thereof.
