Automatic checkout systems to monitor driver's vigilance.

A concept for designing automatic checkout systems to prevent drivers from falling asleep is presented. It is shown that such systems should use the frequency of electrodermal reactions (EDR), which is governed by changes in skin resistance. Such changes have a time constant of several seconds. To detect these reactions, a special technique was developed. Experimental investigations yielded the quantitative characteristics of EDR changes associated with decreased vigilance. It was found that, when a person started to fall asleep, the EDR frequency diminished. An EDR-based system was developed to assess the alertness level. Such a system may be employed to prevent drivers from falling asleep.