Extraction and Analysis of Steady State Somatosensory Evoked Potentials in Lower Limbs

Abstract

Steady state somatosensory evoked potential (SSSEP) is an electrical signal generated in the cerebral cortex under external auxiliary stimulation. In the current literature, there are few studies on the extraction method of SSSEP in lower limbs. In order to be able to extract an effective SSSEP from lower limbs, electrical stimulation with different intensity is executed on the posterior tibial nerve of inner ankle of lower limbs. Select the optimal stimulation frequency combination among 5 stimulation frequency combinations through time-frequency analysis and brain topographic map. The results show that the electrical stimulation intensity of lower limbs is generally about 8 mA~25 mA, and the stimulation intensity of the left and right leg is different. The optimal stimulation frequency combination of the lower limbs is 28 Hz-33 Hz, with the best spectral characteristics for the subject at this frequency combination.