Bidirectional Telemetry System for FES Applications

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