Noise properties of textile, capacitive EEG electrodes

Abstract

The rigid surface of the conventional PCB-based capacitive electrode produces an undefined distance between the skin and the electrode surface. Therefore, the capacitance introduced by them is uncertain and can vary from electrode to electrode due to their different positions on the scalp. However, textile electrodes which use conductive fabric as electrode surfaces, are bendable over the scalp. Therefore, it provides a certain value of the capacitance which is predictable and calculable accurately if the effective distance to the scalp surface can be determined. In this paper noise characteristics of textile electrodes with different fabric sizes as electrode's surface and capacity calculations related to each size are presented to determine the effective distances for each electrode size.