Flexible Finger-Shaped Active Dry EEG Electrode With a Configurable Application-Specific Integrated Circuit and Embedded Leadoff Detection

Abstract

Dealing with the discomfort and complex setting-up of conventional wet electrodes in the electroencephalography (EEG) monitoring for personal daily healthcare, a flexible finger-shaped active dry EEG electrode is developed and tested in this paper. The flexible finger-shaped dry electrodes, made of polydimethylsiloxane (PDMS) and elastic electrically conductive composite (ECC), penetrate through the hair to achieve stable contact with the scalp. To improve the quality of weak signal acquisition, a customized configurable application-specific integrated circuit (ASIC) is integrated using ECC based fabrication process, which amplifies the signal by 100 V/V, detects the lead-off states of electrodes, communicates with the back-end electronic module for configuration and status feedback. The amplifiers have >100 MΩ @ 50 Hz input impedance to match the large interface impedance of dry electrodes. An I2C slave controller with a dedicated wake-up oscillator is introduced for excellent configurability with a reduced number of wires and lower power consumption. Modulus of the proposed electrodes are similar as human tissue, ensuring remarkable user comfort. Besides, the process costs low and mold-casting is suitable for mass production. Over all, the easy-to-use active dry electrode could meet the requirements for daily EEG monitoring.