Design Of Electrotactile Stimulation System And Its Application In Prosthetic Control

Nowadays,the commercial prosthetic hand is often rejected by amputees because of the lack of sensory feedback.Thus electrotactile stimulation is introduced in the paper to close the loop and improve the effect on amputee’ s control of the prosthetic hand.Modular design concept is introduced to achieve human-machine interface.A wearable armband based on electrotactile stimulation is designed including the electrodes design,the hardware and software design for the portable stimulator.Finally,the current of different parameters was evaluated and meanwhile,the effectiveness of the armband was verified by experiments on subjects.To achieve the close-loop control for the prosthetic hand,a system is designed consisting of the driving circuit board with algorithm in software for prosthesis and modular thimbles in which the pressure sensor modules are embedded.By conducting experiments on subjects for recognition of stiffness and different bottles using different feedback methods,the system was evaluated.The results of the experiments on bottles grasping showed the electrotactile feedback could improve the successful rate effectively.Based on the electrotactile armband,the coding schemes were explored by mixing different spatial coding with frequency coding schemes in the limited skin field for stimulation.The results of the experiment advised the best choices of the mixed coding schemes for different requirements.To further improve the gesture feedback for the prosthetic hand,an electrical stimulator with high-density arrays is applied to activating the muscles in the hand.Experiments for recognition of proprioception were conducted.These researches above provide solutions for improving the sensory feedback of prosthetic hand.