Design a brain computer interface gaming system using steady-state visual evoked potential

The brain computer interface (BCI) is an emerging technology for paralyzed people to communicate with external environments through their minds. However, current EEG equipment utilizes metal electrodes, such as gold cup, AgCl, etc., with electrolytes to attach on human skin. These wet-type electrodes are not convenient for use. It usually requires a lousy preparation process and the refill of electrolyte after using one or two hours. In this study, the dry-electrode IMEC headset V1 system was adopted to implement a brain computer interface. Two visual stimuli, flickering at 15 and 17Hz were presented on a LCD screen. Subject´s 15 Hz or 17 Hz steady-state visual evoked potential (SSVEP) was induced to control a virtual claw machine. Users gazed at the 15 Hz stimulus to control the movement of the claw and the 17 Hz stimulus was used to clamp objects. During the operation, users gazed at one intended targets to activate its corresponding function. The proposed system has been tested in three volunteers, and the mean accuracy and mean information transfer rate (ITR) were 96% and 18.23 bits/min, respectively. According to our experience, the operation accuracy of the BCI system is related to subject´s attention level. Higher concentration level will result in better accuracy. The proposed BCI system can also be used for paralyzed patients to control home facilities for self-caring purpose in the future.