[Closed-loop regulation system for paralyzed lower limb joint movement based on electrical stimulation of spinal central pattern generator].

Intraspinal microstimulation (ISMS) is a rehabilitation technology that activates muscle movement by electrically stimulating the spinal cord, thereby restoring the function of paralyzed limbs. In this study, a fuzzy logic-controlled self-tuning proportional-integral-derivative (PID) algorithm was adopted. By simultaneously adjusting three key electrical stimulation parameters-amplitude, pulse width, and frequency of the pulse signal-the distal locomotor central pattern generator (CPG) in rats with spinal cord injury (SCI) was activated, realizing real-time control of hindlimb ankle joint movement in paralyzed rats. To verify the control performance of the intraspinal microstimulation system, animal experiments were conducted. Statistical results showed that the root mean square error (RMSE) of joint angle tracking was 2.50°, and the normalized root mean square error (NRMSE) was 5.78%. The results indicate that the ankle joint of the paralyzed hindlimb in SCI rats can move according to the preset angle trajectory through single-electrode intraspinal electrical stimulation.