Embedded fuzzy logic controller for functional electrical stimulation system

Functional electrical stimulation (FES) is one of the most common techniques used to improve motor function in individuals with paralysis. In this study, fuzzy logic controller implemented in embedded system for wearable FES was developed. The controller was designed as Single Input Single Output (SISO) and Multi Input Single Output (MISO) controllers to manage electrical stimulation for seven muscles in thigh and shank and to induce certain joint movements. The system was realized in two steps utilizing 32-bit ARM microcontrollers, STM32F429 and STM32F103C8T6, respectively. Closed-loop control was used in the system and realized using feedback from the sensors. Serial communication was utilized for data transmission between embedded system and PC/laptop as monitoring station. Experiments done to test the performance of SISO controller of knee flexion proved that the system was able to adjust burst duration and to control joint movement induced. The system designed was expected to be helpful for clinical application of motor function improvement.