Comparative Study on Conductive Knitted Fabric Electrodes for Long-Term Electrocardiography Monitoring: Silver-Plated and PEDOT:PSS Coated Fabrics

Abstract

Long-term monitoring of the electrical activity of the heart helps to detect the presence of potential dysfunctions, enabling the diagnosis of a wide range of cardiac pathologies. However, standard electrodes used for electrocardiogram (ECG) acquisition are not fully integrated into garments, and generally need to be used with a gel to improve contact resistance. This article is focused on the development of washable screen-printed cotton, with and without Lycra, textile electrodes providing a medical quality ECG signal to be used for long-term electrocardiography measurements. Several samples with different Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) concentrations were investigated. Silver-plated knitted fabric electrodes were also used for comparison, within the same process of ECG signal recording. The acquisition of ECG signals carried out by a portable medical device and a low-coast Arduino-based device on one female subject in a sitting position. Three textile electrodes were placed on the right and left forearms and a ground electrode was placed on the right ankle of a healthy female subject. Plastic clamps were applied to maintain electrodes on the skin. The results obtained with PEDOT:PSS used for electrodes fabrication have been presented, considering the optimal concentration required for medical ECG quality and capacity to sustain up to 50 washing cycles. All the ECG signals acquired and recorded, using PEDOT:PSS and silver-plated electrodes, have been reviewed by a cardiologist in order to validate their quality required for accurate diagnosis.

PEDOT:PSS-Based Conductive Textiles and Their Applications

“…Ankhili et al developed an ECG sensor electrode from a PEDOT:PSS screen-printed cotton fabric and obtained a clear ECG wave amplitudes up to 50 washing cycles [94]. The same group also produced washable screen-printed cotton textile electrodes with and without lycra of different PEDOT:PSS concentration, providing a medical quality ECG signal to be used for long-term ECG measurements with a similar result to silver-plated cotton fabric at 12.8 wt% of PEDOT:PSS to pure cotton [95]. Niijima et al produced "hitoeCap" from PEDOT:PSS textile electrodes for securing electromyography of the masticating muscles [96].…”

Protocol to assess the quality of transmission lines within smart textile structures

“…It still requires new standards based on hybrid nature and cooperation of both industries. For instance, even this new industry attracted the customers and gained level of maturity, yet it is facing hurdles in terms of reliability and washability [3,[28][29][30]. For the successfulness of e-textile clothing in the market, all available components should be reliable and able to withstand certain number of washing cycles.…”

Surface modification of textile electrodes to improve electrocardiography signals in wearable smart garment

“…However it is believed that PEDOT-PSS shows hydrogel properties under wet conditions, which reduce its mechanical strength according to its water content [46], and in turn results in exfoliation from the substrates and a loss of electrical conductivity. Recently, a comparative study on silver-plated and PEDOT:PSS coated fabrics for long term monitoring [47] has shown that for both types of textile electrodes, all electrocardiographic signals were identifiable, despite higher contact impedance of PEDOT:PSS textile electrodes. The initial surface conductivity and tolerance against repetitive washing was better in PEDOT:PSS only in the case that higher amounts of PEDOT:PSS were used (pure cotton and 12.8 wt% PEDOT:PSS).…”