An implantable fluid operated device may include a fluid reservoir configured to hold fluid, an inflatable member, and a pump assembly configured to transfer fluid between the fluid reservoir and the inflatable member. The pump assembly may include one or more fluid pumps and one or more valves. An electronic control system may control operation of the pump assembly based on fluid pressure measurements and/or fluid flow measurements received from the one or more sensing devices. The electronic control system may include an internal component installed with the implanted device, and an external component that is operable by a user to provide user input, and to receive output from the implanted device.