| With the development of science and technology,haptic feedback technology has been widely used in life,especially in remote sensing operations,games,medical treatment and other aspects of haptic feedback technology has broad prospects.Among the various tactile reproduction methods,electric tactile sensation has attracted extensive attention from researchers due to the characteristics of flexible stimulation,simple implementation device,and precise controllability of pulse parameters.At present,the research of virtual tactile feedback based on micro-current stimulation mainly has the following problems:(1)Most of the stimulation electrodes used in the existing electric tactile research are surface-type single electrodes.During the process of electrical stimulation,as the posture of the subject's stimulation site changes,relative movement between the surface electrode and the stimulation target is likely to occur,which affects the stimulation effect.(2)In the current neuronal electrophysiology research,only the analysis of the pulse shape on the stimulus response is conducted,and the relationship between the pulse parameter and the nerve fiber stimulus response is not analyzed.(3)At present,most of the electric tactile feedback research is carried out for the qualitative analysis of the stimulus function and stimulus mode of related models.There is no quantitative evaluation method for the gradation experiment of tactile reproduction,so it is difficult to compare the advantages and disadvantages of the stimulus results.This article will conduct the following research on several key issues in the existing research:(1)Aiming at the problem of stimulation target movement during electrical stimulation,a flexible electrode array composed of multiple electrode contacts is designed.By increasing or decreasing one or more channels of stimulation pulses,the activated electrode contacts are changed to achieve the stimulation position As well as the dynamic adjustment of the stimulation range,compared with the stimulation electrodes used in related literature,it has superior performance in improving stimulation selectivity and control ability.Experiments have shown that when the size of the large and small electrode contacts is within 12-14 mm and 7-9mm,and the electrode spacing is within 2-6mm,the accuracy of stimulation is optimal.(2)In the study of neuronal electrophysiology,based on the limitations of model analysis,establish a nerve fiber conduction model to study the relationship between electrical pulse parameters and nerve fiber stimulus response,and select three kinds of pulses with different waveforms,and design multiple sets of contrast experiments with different pulse parameters under the same waveform.Compared with other literatures,the analysis of nerve fiber stimulus response in this paper is more comprehensive and detailed.(3)Propose a skin electrical stimulation model,conduct simulation experiments based on the model stimulus function and determine current parameters,and design electrophysiological tactile grading experiments;In view of the limitations of the evaluation method,a quantitative evaluation method based on electrophysiological touch grading experiments is proposed to quantitatively evaluate the actual reproduction effect of skin receptors under different stimulation modes;The quantitative evaluation results of Meissner's corpuscle and Merkel's disk are consistent with the simulation results,and achieving a good evaluation effect.In this thesis,the research work of electrical tactile stimulation is carried out by combining neuronal electrophysiological mechanism and action potential theory.Based on the analysis of nerve fiber action potential conduction,the establishment of human skin electrical stimulation models and the design of electrical tactile physiology experiments provide a new idea for the research of electrical stimulation-based tactile feedback. |
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