Journal of Radio Electronics. eISSN 1684-1719. 2025. ¹11
Full text in Russian (pdf)
DOI: https://doi.org/10.30898/1684-1719.2025.11.33
DEVELOPMENT OF ACTIVE RESISTIVE-CAPACITIVE ELECTRODES
AND STUDY OF CIRCUIT ENGINEERING METHODS
FOR MINIMIZING ELECTRODE NOISE
IN THE “OPEN BCI” EEG SIGNAL RECORDING SYSTEM
D.V. Zhuravlev, A.N. Golubinsky, N.A. Letov
Voronezh State Technical University
394006, Russia, Voronezh, 20th Anniversary of October str., 84
The paper was received September 5, 2025.
Abstract. The article presents the developed active resistive-capacitive electrodes with a single gain. The electrodes are intended for use in the brain-computer interface system based on the hardware solution of the “OpenBCI” open project (Cyton registration board). Options for the circuit design of a common (reference) electrode and an active noise reduction electrode are also presented. Both circuit design and technological solutions of printed circuit boards of the developed electrodes are described. A comprehensive study has been conducted on the effect of various connection options to the registration board and circuit designs of electrodes on parameters such as Common Mode Rejection Ratio, signal-to-noise ratio and Noise factor. Simulation modeling and calculation of the parameters of the proposed options for connecting electrodes to biopotential amplifiers have been carried out. Both monopolar and bipolar methods of connecting electrodes have been investigated. Options with and without an additional bias electrode (noise reduction) have also been investigated. Connection methods and circuit design have been identified to achieve the best values of the parameters under consideration. Mock-ups of electrodes were made and field experiments were carried out with the direct recording of signals by the entire “Open BCI” system. Calculations of the considered parameters are carried out. As a result of measurements, the effectiveness of the developed methods of connecting electrodes and their circuit design options has been confirmed in practice. The value of this work lies in the fact that the parameters under consideration were calculated after recording the signals from the Cyton board as they passed through the entire system, including resistive-capacitive electrodes and a recording board. The developed implementation of the electrodes has shown its effectiveness by working in the “Open BCI” system. The best values of the measured parameters obtained after field experiments were 98.95 dB for the Common Mode Rejection Ratio, 0.421 dB for the noise factor.
Key words: brain-computer interface, resistive-capacitive, capacitive, dry active electrodes, Cyton board, common-mode attenuation coefficient, noise coefficient.
Financing: The research was carried out at the expense of a grant from the Russian Science Foundation No. 24-29-20168, https://rscf.ru/project/24-29-20168/.
Corresponding author: Zhuravlev Dmitry Vladimirovich, ddom1@yandex.ru
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For citation:
Zhuravlev D.V., Golubinsky A.N., Letov N.A. Development of active resistive-capacitive electrodes and study of circuit engineering methods for minimizing electrode noise in the “Open BCI” EEG signal recording system // Journal of Radio Electronics. – 2025. – ¹. 11. https://doi.org/10.30898/1684-1719.2025.11.33 (In Russian)