Non-contact Wearable EEG Sensors for SSVEP-based Brain Computer Interface Applications.

Electroencephalography (EEG) based brain computer interfaces (BCI) introduces promising communication pathway between the brain and external devices, not only for the motor-impaired but also the healthy users. However, the current EEG-based interface device is not convenient enough for daily uses. In this study, we developed an EEG acquisition system that records brain signals without contacting scalp. The proposed system consists of a small sized ($5.5\,\times 3\,\mathrm{cm}^{2}$ acquisition hardware and four stainless steel electrodes integrated in a regular sport hat. To demonstrate the concept, we used an in-house developed steady-state visual evoked potentials (SSVEP) paradigm and recorded EEG signals using the proposed system. The EEG signals were compared with three different brain states - Eye Closed, Eye Open, and Visual Stimulation. The results show that the BCI system can record SSVEP from the brain without any professional setups or expensive dry-electrodes.