Reconstruction Of Sensory Feedback Channels Based On Evoked Tactile Sensation And Its MEG Verification

Prosthetics are the gospel of amputees,but the lack of perceptual feedback has become a bottleneck.A multi-channel sensing feedback system is built based on evoked tactile sensation with electrical stimulation.The system generates the corresponding electrical stimulation signals by the pressure on the prosthetic hand acting on the subject’s induced finger-sensing area to achieve perceptual feedback of pressure.At the same time,this project also makes a preliminary exploration of temperature feedback.A rapid prediction model of temperature is established,which provides the possibility of predicting temperature within 1 second based on the rate of sensor response.In addition,we also verify the hypothesis that electrical stimulation of projected finger map(PFM)in the stump skin of forearm amputees activates concurrently the corresponding finger areas in the somatosensory cortex(S1).The S1 responses are observed using the neuroimaging technique of Magnetoencephalography(MEG).In the experiments with an amputee,three groups of sites were stimulated:(1)the thumb and little finger areas of the PFM on the stump skin of the amputee subject;(2)the thumb and littler fingers of the contralateral hand of the subject;and(3)the contralateral forearm skin areas matching the PFM in the amputated stump.MEG results indicated that PFM stimulation evoked S1 activation consistent with homunculus organization.This may imply that the thumb and little finger areas in the PFM on the stump skin are connected neuroanatomically to the thumb and little finger areas in S1 after amputation.