Wearable stimulator for SSVEP-based Brain-Computer Interfaces

Brain-Computer Interfaces based on Steady-State Visual Evoked Potentials require the user to focus attention on an external stimulus, which is almost always fixed at a specific location. Therefore, it is nearly impossible to focus on a stimulus to produce SSVEP activity while simultaneously observing the environment, especially a mobile environment. A compromise has to be found in applications that requires user´s attention to the stimulus as well as to the environment (e.g., controlling a wheelchair, moving a robot arm). This paper describes a wearable SSVEP stimulator to keep the stimulus always in the user´s field of view. The stimulus is mounted on a transparent visor cap which allows to keep attention to the environment and the stimulus the same time. An experiment with 6 healthy subjects has shown similar results for the visor cap in comparison to a stimulus fixed on a table.