A noninvasive brain computer interface using visually-induced near-infrared spectroscopy responses.
Visually-induced near-infrared spectroscopy (NIRS) response was utilized to design a brain computer interface (BCI) system. Four circular checkerboards driven by distinct flickering sequences were displayed on a LCD screen as visual stimuli to induce subjects' NIRS responses. Each flickering sequence was a concatenated sequence of alternative flickering segments and resting segments. The flickering segment was designed with fixed duration of 3s whereas the resting segment was chosen randomly within 15-20s to create the mutual independencies among different flickering sequences. Six subjects were recruited in this study and subjects were requested to gaze at the four visual stimuli one-after-one in a random order. Since visual responses in human brain are time-locked to the onsets of visual stimuli and the flicker sequences of distinct visual stimuli were designed mutually independent, the NIRS responses induced by user's gazed targets can be discerned from non-gazed targets by applying a simple averaging process. The accuracies for the six subjects were higher than 90% after 10 or more epochs being averaged.
['Chen|Cheng-Hsuan|CH|', 'Ho|Ming-Shan|MS|', 'Shyu|Kuo-Kai|KK|', 'Hsu|Kou-Cheng|KC|', 'Wang|Kuo-Wei|KW|', 'Lee|Po-Lei|PL|']
D000328:Adult D001921:Brain D062207:Brain-Computer Interfaces D005260:Female D006801:Humans D008297:Male D010775:Photic Stimulation D019265:Spectroscopy, Near-Infrared D014796:Visual Perception D055815:Young Adult
Brain computer interface Flickering sequence Visual response Hemodynamic response Near infrared spectroscopy