Development of a Wearable EEG Device Toward BCI Applications

Abstract: Electroencephalogram (EEG) technology is being explored for a wide range of applications, including healthcare, disability assistance, and brain-computer interface (BCI). However, EEG devices commonly used in laboratories are often expensive and not portable. In this study, we developed and evaluated an inexpensive, wearable EEG device as an alternative to the high-performance but immobile EEG1000 system. Long battery life is also a key requirement. Devices with these characteristics are useful for collecting data from individuals who cannot visit laboratories, such as bedridden patients, and for evaluating BCI technology in more practical settings. In particular, for studies involving a large number of participants, low-cost devices can be loaned individually, enabling efficient data collection. The developed EEG device employs a differential amplifier circuit with passive electrodes. It consists of a single-channel analog front-end and a digital section for A/D conversion and wireless transmission to a PC via Bluetooth Low Energy (BLE). The passband is 0.159–100 Hz, the sampling rate is 1 kHz, and the resolution is 16-bit within a 0–3.3 V range. Transient analysis, AC analysis, common-mode rejection ratio (CMRR), and noise analysis were conducted using a simulator. Additionally, alpha waves were recorded under eyes-open and eyes-closed conditions. These measurements were conducted simultaneously with the EEG1000 for comparison, serving as a fundamental test for BCI applications. In all 10 participants, the expected increase and decrease in alpha activity were observed. However, the alpha response was more clearly detected with the EEG1000. Future improvements will focus on enhancing performance through the adoption of active electrodes and multi-channel configurations.

Keywords: electroencephalogram, wearable, brain-computer interface

DOI: 10.54941/ahfe1006892

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