Citation

Hefner R, Edwards D, Heinze C, Sommer D, Golz M, Sirois W, Trutschel U. Proc. Int. Driv. Symp. Hum. Factors Driv. Assess. Train. Veh. Des. 2009; 5: 110-117.

Copyright

(Copyright © 2009, University of Iowa Public Policy Center)

DOI

unavailable

PMID

unavailable

Abstract

This study was designed to evaluate the viabililty of utilizing Tachograms for estimating fatigue in industrial and transportation applications. To explore this possibility Tachograms were recorded continuously and several heart rate measures were calculated and correlated with other well established fatigue measures. It was anticipated that changes in operator fatigue during a night time study could be depicted during three different conditions. In the first condition, a 40-minute monotonous driving task, Karolinska Sleepiness Scale (KSS), Variation of Lane Deviation (VLD), number of Micro-Sleep Events (MSE), numbers of accidents, and the PERCLOS score were collected as subjective and objective fatigue measures. In the second condition, a 10-minute Compensatory Tracking Task (CTT), the Mean Distance (MD) of a moving disk to a given target, the Standard Deviation of the Distance (SDD), as well as the Mean Velocity (MV) of the disk and the Standard Deviation of the Velocity (SDV) over the test duration were used as fatigue measures. In the third condition, a 5-minute Psychomotoric Vigilance Test (PVT), the Mean Response Times (MRT), the Standard Deviation of the Response Times (SDRT), the Mean of the inverse of the Slowest 10% of Response Times (MS10% 1/RT), and the number of lapses were used as fatigue measures. Correlations between heart rate and fatigue measures were calculated and classified using experimental results of one volunteer, who completed two nighttime episodes in a real-car lab following a partial sleep deprivation design. Results show strong correlations between heart rate variability (HRV) measures and multiple fatigue measures.