Journal of Signal Processing
Online ISSN : 1880-1013
Print ISSN : 1342-6230
Current issue
Journal of Signal Processing, Vol.22 (2018) No.5 (Editor-in-Chief: Keikichi Hirose, Editor: Tetsuya Shimamura, Honorary Editor-in-Chief: Takashi Yahagi)
Showing 1-2 articles out of 2 articles from the selected issue
  • Naoki Fujiwara, Takumi Fukunaga, Akihiro Tanaka, Satoru Kishida
    2018 Volume 22 Issue 5 Pages 227-239
    Published: September 20, 2018
    Released: September 20, 2018

    We tried to measure fatigue levels by using several biological information, such as heart rates, flicker levels (F-values) or relative flicker value (ΔF-values) and ATMT (Advanced Trail Making Test) method. From the testing results, we found that there is a positive correlation between heart rates and F-values in the range of 'waking up' to 'awaking' stages, and the heart rates were independent of 'awaking' to 'sleep' stages. The result indicates that heart rates and F-values are related to fatigue levels. In addition, the maximum F-values and then slow decrease of F-value among the examinees correspond to 'perfect awakening' and fatigue levels in 'daily life'. Those results indicate that centrally acting fatigue is able to be measured with ΔF-value and physical fatigue levels were measured with ΔF-values when heart rates are approximately equal to before and after negotiating stairs. The F-values of the examinees decrease after consuming alcohols and then recover a few hours later, which were consistent with their blood alcohol levels. Therefore, the F-values are considered to be related with fatigue and blood alcohol level, because alcohol consumption causes indispensable symptoms of fatigue. As a result, we were able to measure various fatigue relating factors including centrally acting fatigue, physical fatigue and the fatigue of eyes, by using key biological information namely heart rates, F- or ΔF-values and ATMT method.

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  • Nobuo Nagai, Takashi Yahagi
    2018 Volume 22 Issue 5 Pages 241-242
    Published: September 20, 2018
    Released: September 20, 2018