Gastric banding devices, and drive systems designed to operate gastric banding devices, are disclosed. The gastric banding devices and drive systems intend to increase performance, durability, and simplicity over known gastric banding systems. Embodiments include transmission systems configured to output a variable force. Embodiments also include banding structures biased to apply a constrictive force to a patients stomach. Supporting, or skeletal, structures are also disclosed. Various drive systems designed to improve power efficiency are also disclosed.
