Characterization of screen-printed textile electrodes based on conductive polymer for ECG acquisition

The goal of this work was the characterization of textile ECG electrodes produced by screen printing with poly-3,4-ethylenedioxythiophene doped with poly(styrene sulfonate) (PEDOT:PSS) conductive organic polymer. In particular, screen printed ECG electrodes were analyzed in the light of the ANSI/AAMI standard EC 12:2000 to reasonably understand their potentialities for the development of smart garments. In fact, smart garments have to be able to resist to everyday use, including the typical garment maintenance. Simulated washing cycles were performed following the ISO 105-C10:2006 standard, monitoring the variation of the noise and impedance, through bench procedures. Human tests revealed how the ECG signals obtained with screen printed electrodes were comparable to those achievable with disposable gelled Ag/AgCl ones. The high skin-electrode contact impedance of brand new electrodes in dry condition limited their usability, whereas the addition of an electrolyte led to comparable signal quality. Remarkably, washing cycles ameliorated the performance in dry conditions up to acceptable levels. This technique can then be used to create electrodes on finished garments, able to resist to everyday use.