A Functional Electrical Stimulation (FES) system provides frequency division multiplexed transmission of control signals from a master controller to a multiplicity of microstimulators. FES systems utilize the multiplicity of microstimulators to provide electrical signals to stimulate nerves and muscles...http://www.google.ca/patents/US20010053926?utm_source=gb-gplus-sharePatent US20010053926 - Combined frequency-domain time-domain multiplexing of radio frequency communications with multiple implanted devices
