Potential of M-Wave Elicited by Double Pulse for Muscle Fatigue Evaluation in Intermittent Muscle Activation by Functional Electrical Stimulation for Motor Rehabilitation

Figure 4

Conceptual diagram of cycle-to-cycle control in controlling maximum knee extension angle in the swing phase of walking (a) and block diagram of the FES control used in this study (b). The maximum knee extension angle was controlled at the sitting position by electrical stimulation based on cycle-to-cycle control in this study. , , and show the target angle, controlled maximum angle, and joint angle change to single stimulation burst. is the burst duration. shows muscle sensitivity. E-OAF (error-based output adjustment factor) and S-OAF (sensitivity-based output adjustment factor) adjust output of the fuzzy controller in order to improve control ability.

(a) Conceptual diagram

(b) Block diagram