| Budget Amount *help |
¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1995: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1994: ¥800,000 (Direct Cost: ¥800,000)
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| Research Abstract |
In the present study, quantitative elucidation of relationship between the vigilance level and various parameters of the open eyes and physiological parameters was investigated. A video screen of simulating car driving was presented to nine healthy adult subjects while eye openness, blinking frequency, eye movement, EEG (O_z-C_z, C_3-C_z), ECG and sleepiness (Kuwansei Gakuin Sleepiness Scale, KSS) were recorded. Recordings were made at midnight in four sections consisting of each 15-20 min session interspaced by a 5-10 min rest period and at the daytime in one session. Mean values of each parameter were obtained for each recording session.
The blinking frequency initially increased with increasing of KSS but decreased with further increasing of KSS and individual variations were considerable in this parameter. Eye openness remained nearly the same as in the high arousal level up to ca.4.7 of KSS,above which it rapidly decreased with increasing of KSS.Eye movement decreased as KSS increased, but the mode of decrease was relatively linear in comparison with eye openness. In the EEG,the %alpha-power and its gradient increased with increasing of KSS.The %delta-power tended to decrease above 4.5 of KSS.The %beta-power tended to decrease with increasing of KSS without reaching the level of statistical significance. The %rheta-power did not show any significant changes. In the ECG,the R-R interval and the degree of its fluctuation increased with increasing of KSS.From these results it was suggested that 1) eye openness could be a good indicator of intense drowsiness, 2) the %alpha-power of the EEG is a good parameter of vigilance level, 3) there may be some correlation between the parameter changes of the open eyes and those of EEG and ECG.
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