Novel passive ceramic based semi-dry electrodes for recording electroencephalography signals from the hairy scalp

Abstract

This study reports on a novel passive ceramic-based semi-dry electrode prototype for electroencephalography (EEG) applications. With the help of capillary forces of the porous ceramics pillars, the semi-dry electrodes build a stable electrode/scalp interface by penetrating hair and releasing a small amount saline in a controlled and sustained manner. The semi-dry electrode/scalp impedances were low and stable (44.4 ± 16.9 kΩ, n=10), and the variation between nine different positions was less 5 kΩ. The semi-dry electrodes have shown non-polarization characteristics and the maximum difference of equilibrium potential between eight electrodes was 579 μV. The semi-dry electrodes demonstrated long-term stability, and the impedance only increased by 20 kΩ within 8 h. EEG signals were simultaneously recorded using a 9-channel gel-based electrode and semi-dry electrode arrays setup on ten subjects. The average temporal cross-correlation between them in the eyes open/closed and the steady state visually evoked potentials (SSVEPs) paradigm were 0.938 ± 0.037 and 0.937 ± 0.027 respectively. Spectral analyses revealed similar response patterns with expected functional responses. Together with the advantages of quick setup, self-application and cleanliness, the result suggests the semi-dry electrode is suitable for emerging real-world EEG applications, such as braincomputer interfaces and wearable EEGs.

Facile Synthesis of MnO2 Nanoflowers/N-Doped Reduced Graphene Oxide Composite and Its Application for Simultaneous Determination of Dopamine and Uric Acid

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A Protocol for Comparing Dry and Wet EEG Electrodes During Sleep

“…EEG measurements can be performed with different types of re-usable dry electrodes. Pin-type electrodes are designed to reach the scalp through dense hair, but because they are not attached to the skin directly, they have the disadvantage of being subject to strong motion artifacts and can change position throughout the night (Li et al, 2016). Therefore, they require high pressure on the scalp to ensure high signal quality which causes discomfort and even pain during prolonged use (Gao et al, 2018).…”

Fabrication of Flexible Microneedle Array Electrodes for Wearable Bio-Signal Recording

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