Electrochemical modeling and evaluation for textile electrodes to skin

Fan Li,Kui Zhang,Jinzhong Song,Yijing Yang,Yu Zhang,Hao Liu,Qingjun Liu,Zhi Xu,Jingsong Li,Tianshu Zhou

doi:10.1186/s12938-020-00772-5

Abstract

BackgroundWith the development of wearable health-monitoring technologies, a variety of textile electrodes have been produced and applied by researchers. However, there are no universal and effective methods even testing platforms for evaluating the skin–electrode electrochemical interface for textile electrodes because different human bodies have different skin characteristics.MethodsAn electrochemical modeling and evaluation for textile electrodes to skin was proposed, and two electrochemical evaluation platforms (EEP) were set up based on two simulated skin models (SSM). First, skin–electrode electrochemical interface (SEEI) models for traditional wet electrodes and textile electrodes were analyzed. Based on the SEEI models and YY/T 0196-2005 (Chinese YY/T pharmaceutical industry standard for disposable ECG electrode), three skin–electrode electrochemical characteristics (SEEC), including skin–electrode static impedance (SESI), skin–electrode alternating current impedance (SEAI), and skin–electrode polarization voltage (SEPV), were proposed. Then, three electrochemical evaluation methods for textile electrodes to skin were proposed and analyzed, which were the correlation between SEEC and skin–electrode contact pressure (SECP), skin–electrode relative movement (SERM), and conduction loss of active signals (CLAS). Finally, an electrochemical evaluation platform was set up based on an active simulated skin model (ASSM) and passive simulated skin model (PSSM).Results9 feature parameters based on the passive electrochemical evaluation platform (PEEP) and 11 feature parameters based on the active electrochemical evaluation platform (AEEP) were obtained for evaluating textile electrodes. And four kinds of textile electrode characteristics including SEEC, SECP, SERM, and CLAS were quantitatively measured based on the electrochemical evaluation platform, and the testing accuracy and range for these characteristics were measured separately. Finally, correlation between SEEC and SECP for 10 kinds of textile electrode samples was studied, and 14 electrochemical characteristics and four skin–electrode contact pressure characteristics were extracted. Experimental results showed that significant correlations were found between six SEEC characteristics and SECP characteristics, and the correlation coefficient between ACI_3 and USECP was the highest. And the polarization voltages of most dry electrode samples showed a downward trend with the increase of contact pressure.ConclusionsThe electrochemical evaluation platform yielded effective experimental data and could provide strong support for the evaluation and application of textile electrodes, which was also effective in evaluating other bioelectric electrodes such as 3M electrode, stainless steel electrode, dry electrode and microneedle electrode.

Highlights

With the development of wearable health-monitoring technologies, a variety of textile electrodes have been produced and applied by researchers
The electrochemical evaluation platform yielded effective experimental data and could provide strong support for the evaluation and application of textile electrodes, which was effective in evaluating other bioelectric electrodes such as 3M electrode, stainless steel electrode, dry electrode and microneedle electrode
The reasons for this research The reasons why we studied the skin–electrode electrochemical interface for wearable textile electrodes are shown as follows: Wearable dry biomedical electrodes, such as textile electrodes, noncontact electrodes, and microneedle electrodes, are one type of wearable sensor technologies and have been studied by an increasing number of researchers [18,19,20,21,22,23,24,25,26]

Summary

Introduction

With the development of wearable health-monitoring technologies, a variety of textile electrodes have been produced and applied by researchers. There are no universal and effective methods even testing platforms for evaluating the skin–electrode electrochemical interface for textile electrodes because different human bodies have different skin characteristics. Biomedical signals, such as electrocardiograms (ECGs), electroencephalograms (EEGs), electro-oculograms (EOGs), and electromyograms (EMGs), are widely used in patient monitoring, health examinations and family care, which provide an important basis for human health examinations [1, 2]. A variety of wearable dry electrodes have attracted attention because they are used to obtain biomedical signals from human bodies with less skin pretreatment and conductive paste. Wearable, washable, and stable, which are divided into active and passive electrodes according to whether they can be integrated with signal recording and processing circuit units

Methods

Results

Discussion

Conclusion