A dry electrode concept for SMR, P300 and SSVEP based BCIs

A BCI enables a new communication channel that bypasses the standard neural pathways and output channels and in order to control an external device. Recently BCI systems are used for communication purposes, to control robotic devices to control games or for rehabilitation. A limiting factor in the wide-spread application is the usage of abrasive gel and conductive paste to mount EEG electrodes. Therefore many research groups are now working on the practical usability of dry electrodes to completely avoid the usage of electrode gel. In this chapter results for endogenous and exogenous BCI approaches are presented and discussed based on the g.SAHARA dry electrode sensor concept. Power spectra, time courses of evoked potentials, ERD/ERS values and BCI accuracy are compared for three BCI setups based on P300, SMR and SSVEP BCIs. Although the focus in this study was set to P300 evoked potentials it could be demonstrated that the used electrode concept works well for P300, SMR and SSVEP based BCIs.