A microprocessor based bidirectional telemetry system is to be developed which will enable a controller of a Functional Electrical Stimulator (FES) to acquire analog and digital signals necessary for the control of stimulated muscle motion in the hemiplegic or hemiparetic patient. The signals will be derived from transducers positioned on the patient's body, such as foot sensors, goniometers and accelerometers. The system will preprocess these signals and either upon demand or in a regularly timed report format send the content of those signals to the FES controller. The system will consist of multiple physically identical units. Each unit will be individually programmed for a certain task or function. As FES stimulators become more sophisticated and implanted stimulators become a reality, the need to have distributed data processing and remote signal sensing will become important. The telemetry system described here will offer a number of advantages over traditional hard wire signal sensing and processing including: l) a bidirectional communication link; 2) on-board microprocessor to pre-process signal information; and 3) down-loadable program instructions to provide custom task-specific functions to individual telemetry units and the telemetry system as a whole and 4) most importantly it would eliminate the cabling between transducers in a multichannel FES system and the stimulation controller.
