A marker circuit to enable recording of auditory evoked potential using a wireless EEG system (EPOC) and a portable computer

Johnson Thie
This paper describes a circuit that enables auditory evoked potential recordings using a wireless EEG device (Emotiv EPOC) and a portable computer as the stimulus machine. The need arises since neither the portable computer nor EPOC has serial/parallel ports to send/receive marker signals that indicate the stimulus onset. The circuit produces a pulse on the EEG channels when it detects an audio stimulus. First it amplifies the audio tones produced by the stimulus machine and...