Fig. 1
Closed-loop optogenetic system. a Schematic of system design for CL-FOS. The peroneal or tibial nerve was optically stimulated using an LED, resulting in a contraction of the tibialis anterior or gastrocnemius muscle, yielding dorsiflexion or plantarflexion, respectively. Measurement of the footpad displacement was fed into the controller, which modulated the stimulation intensity to bring the limb to the desired angle. b Control diagram depicting pseudo-SITO (single input, two outputs) structure employed for CL-FOS control of the joint angle with PI gains where f: frequency, DC: duty cycle. c Representative trial of CL-FOS accuracy under PI control utilizing a virally transduced rat. Average SSRMSE was 3.01 ± 1.32% for square wave patterns and 1.16 ± 0.93% for sinusoidal patterns (n = 12). d Representative trial of CL-FES accuracy under PI control utilizing a virally transduced rat. Average SSRMSE was 6.31 ± 2.98% for square wave patterns and 11.18 ± 4.32% for sinusoidal patterns (n = 11)
