D.V. Zhuravlev1, A.N. Golubinsky2

1 Voronezh State Technical University (Voronezh, Russia)
2 A.A. Harkevich Institute of Information Transmission Problems of the RAS (Moscow, Russia)
1 ddom1@yandex.ru, 2 annikgol@mail.ru

Due to the rapid development of technology, an urgent scientific and technical task in human-machine systems is the development of alternative ways of transmitting information over a distance. One of these methods is the transmission of control actions by means of mental (imaginary) commands. The devices processing and transmitting such signals are asynchronous brain-computer interfaces. Due to the very heterogeneous composition of the electroencephalogram signals, the most complex mathematical apparatus and highly sensitive biopotential recording equipment are used to isolate informative patterns. But no matter how advanced the mathematical apparatus is, the necessary classification accuracy cannot be achieved without obtaining high-quality bioelectric signals removed from the human head. At the same time, the priority task in the development of brain-computer interfaces is the use of non-invasive, quickly installed and quick-detachable devices with increased reliability of classification of informative signs in the recorded electroencephalogram signals. The most important initial level in the structure of registration equipment are devices for removing biopotentials from the human head. Since the amplitude of the useful signal is very small (about 10 MV), and the level and amount of interference is high, the reliability and accuracy of the entire brain-computer interface system depends on the quality of the electrodes. In this paper, a study of passive resistive capacitive electrodes has been carried out. The substantiation of the use of resistive capacitive electrodes of the "dry" type in brain-computer interface systems is carried out. Equivalent schemes of skin-electrode transitions for different electrode parameters under different skin conditions are given. Other types of passive electrodes are considered and optimal capacitances and resistances of skin-electrode transitions are calculated. The advantages and disadvantages of electrodes of various types are presented, the optimal values of capacitances and resistances of skin-electrode transitions are determined. A type of dry-type passive electrodes has been identified, which is optimal for use in portable systems. For this type of passive electrodes, two electrode construction options have been studied. A comprehensive study was conducted based on simulation modeling of various skin-electrode transitions. Groups of amplitude-frequency characteristics for various types of electrodes are constructed. The practical significance of the research results lies in the fact that two options for the implementation of resistive capacitive electrodes have been proposed. Simulation modeling of implementation options and evaluation of the characteristics of such electrodes for use in asynchronous brain-computer interfaces have been carried out. As a result of the simulation, it was obtained that the electrodes of the first type (built on the basis of a double-row plug PLD) can provide a signal-to-noise ratio of 132.57 dB at the output of the system, whereas the electrodes of the second type (built on the basis of ABS plastic) are only 124.23 dB. Full-scale tests of manufactured models of resistive-capacitive electrodes of the proposed designs were also carried out. The tests carried out confirmed the calculated data. Practically and theoretically, the expediency of using resistive capacitive electrodes of the "pin" type built on the basis of a double-row plug PLD in asynchronous neurocomputer interfaces without deterioration of the quality of the recorded signal is shown.

Zhuravlev D.V., Golubinsky A.N. Theoretical and practical bases of design options for passive resistive capacitive electrodes for use in asynchronous neurocomputer interfaces. Biomedicine Radioengineering. 2025. V. 28. № 7. P. 50–63. DOI: https:// doi.org/10.18127/ j15604136-202507-06 (In Russian)

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