Conductive textile as wearable electrode in intrabody communications

Abstract

Conventional electrodes are widely used for low‐frequency applications such as biopotential measurements. However, with current advances in intrabody communication (IBC), wearable devices for health monitoring have become popular in biomedical sensing, data acquisition and high‐frequency communication systems. Wearable dry electrodes for health monitoring, made from conductive polymers, are often not properly tested for motion artefacts and lack adequate documentation. Traditionally, wet medical electrodes made with conductive gel degrades as absorption, and evaporation occurs. In this work, we introduce a new wearable dry surface electrode from conductive yarn and characterise it by motion artefact effects at 900 kHz in relation to popular wet electrodes. We also compare measurements of skin‐electrode contact impedance and scattering parameters and show that for 60 min of monitoring, dry electrode made of silver conductive textile changed by 0.82% while Ambu WhiteSensor 4500M changed by 2.25% and Noraxon #270 changed by 1.61% at low frequencies. Thus, our wearable dry electrode has more stable skin‐electrode impedance. Our wearable band electrode had a maximum of 1.0 dB loss when a 0 dB signal is transmitted across a 20‐cm channel length in comparison with Ambu WhiteSensor and Noraxon #270 electrodes which dropped by 2.62 and 2.18 dB, respectively. The result indicates that dry wearable electrodes are more suitable for measurements where body movement is restricted.