Abstract
Menu selection systems using the P300 component of EEG have been under development for environmental control equipment operated by severely disabled persons. Signal processing of 13 Hz low-pass filter, averaging triggered by menu blink start time, and wavelet transform based on Morlet-type are performed and a menu is selected based on the absolute value after the process. Menu selecting experiments with 5 and 25 menus were performed ten times by ten and five healthy subjects. For five menus selection, alphabet A-E are blinked randomly in three different methods by which alphabets are displayed at five or single fixed position, or five random position. The highest success ratio was 70 % by the five fixed position. Three types of blinking methods were then used to investigate 25 menus arranged in 5 columns x 5 rows. For the matrix-type blinking, randomly selected menus of one row and column are blinked in turns. In the hierarchical blinking type, menus of each row are blinked randomly and after selected, menus belonging to the row are blinked. For the random-type blinking, five randomly selected menus are blinked simultaneously. Success ratios were 34%, 74%, and 78% respectively.
