A fluid flow system for a patient comprises a controller and an implantable pump assembly. The controller comprises a processing unit and a battery. The processing unit includes a signal generator and one or more pump operational parameters. The signal generator provides a drive signal. The battery provides power to the processing unit. The implantable pump assembly receives the drive signal from the processing unit and propels fluid based on the drive signal. The system includes a local communication device and a remote communication device that each include a unique identifier produced by a security key generator. The remote communication device includes a code generator that produces encrypted commands. The local communication device receives the encrypted commands and modifies a pump operational parameter of the processing unit based on the received encrypted command.