Verification And Relization Of Sensory Feedback Pathway Based On Evoked Tactile Sensation

For upper limb amputation patients,the lack of hands has caused many inconveniences in life.But the existing prosthetic hands have limited functions,because they can only perform limited functions without sensory feedback.The presence of tactile finger sensation(ETS)can help amputees rebuild the sensory feedback pathway,but the mechanism of sensation is still unclear.Based on the phenomenon of sensory loss in amputees and the phenomenon of ETS,by observing the response of MEG in the brain of the subject under transcutaneous electrical stimulation,the theoretical basis of the existence of induced finger sensation region was explored.At the same time,the response of the brain was recorded by changing the magnitude of the stimulation current.Explore the differences between the ETS and the original sensory attributes of the finger.In addition,based on transcutaneous electrical stimulation technology,an improved multi-channel sensory feedback system has been set up,which can convert the pressure signal to corresponding electrical stimulation signal to stimulate the finger sensation area.This system has the abilities of multi-channel simultaneous pressure acquisition and real-time electrical stimulation.On the basis of this system,an amputee’s finger recognition experiment was performed to test whether the subjects could discern which finger in the projected finger map(PFM)area was stimulated.The existence of the induced finger sensation area was confirmed again on the basis of intuitive experiments.The final results show that the stimulation of the finger region in the PFM produces a neural signal response similar to that of the stimulating healthy finger,and their presence in the cerebral perceptual cortex is symmetrical.At the same time,with the increase of the electrical stimulation intensity,the response intensity of the corresponding area of the brain also increases,which proves that the electrical stimulation intensity has a positive correlation with the response,and the PFM region have the same attribute as original finger sensation.It is proved that there is a connection between the induced finger sensation area and the original finger nerve.