Prolonged Eyelid Closure Episodes during Sleep Deprivation in Professional Drivers.
Real life ocular measures of drowsiness use average blink duration, amplitude and velocity of eyelid movements to reflect drowsiness in drivers. However, averaged data may conceal the variability in duration of eyelid closure episodes, and more prolonged episodes that indicate higher levels of drowsiness. The current study aimed to describe the frequency and duration of prolonged eyelid closure episodes during acute sleep deprivation.



Twenty male professional drivers (mean age ± standard deviation = 41.9 ± 8.3 years) were recruited from the Transport Workers Union newsletter and newspaper advertisements in Melbourne, Australia. Each participant underwent 24 hours of sleep deprivation and completed a simulated driving task (AusEd), the Psychomotor Vigilance Task, and the Karolinska Sleepiness Scale. Eyelid closure episodes during the driving task were recorded and analyzed manually from digital video recordings.



Eyelid closure episodes increased in frequency and duration with a median of zero s/h of eyelid closure after 3 h increasing to 34 s/h after 23 h awake. Eyelid closure episodes were short and infrequent from 3 to 14 h of wakefulness. After 17 h of sleep deprivation, longer and more frequent eyelid closure episodes began to occur. Episodes lasting from 7 seconds up to 18 seconds developed after 20 h of wakefulness. Length of eyelid closure episodes was moderately to highly correlated with the standard deviation of lateral lane position, braking reaction time, crashes, impaired vigilance, and subjective sleepiness.



The frequency and duration of episodes of prolonged eyelid closure increases during acute sleep deprivation, with very prolonged episodes after 17 hours awake. Automated devices that assess drowsiness using averaged measures of eyelid closure episodes need to be able to detect prolonged eyelid closure episodes that occur during more severe sleep deprivation.
Institute for Breathing and Sleep, Department of Respiratory and Sleep Medicine, Austin Health, Melbourne, Australia.|School of Psychological Sciences Monash University, Melbourne, Australia.
Pasquale K
PK
Alvaro
Institute for Breathing and Sleep, Department of Respiratory and Sleep Medicine, Austin Health, Melbourne, Australia.|RMIT University School of Health and Biomedical Sciences, Melbourne, Australia.
Melinda L
ML
Jackson
Institute for Breathing and Sleep, Department of Respiratory and Sleep Medicine, Austin Health, Melbourne, Australia.|University of Melbourne Department of Medicine Austin Health, Victoria, Australia.
David J
DJ
Berlowitz
Department of Road Safety, Vic Roads, Victoria, Australia.
Philip
P
Swann
Institute for Breathing and Sleep, Department of Respiratory and Sleep Medicine, Austin Health, Melbourne, Australia.|School of Psychological Sciences Monash University, Melbourne, Australia.|University of Melbourne Department of Medicine Austin Health, Victoria, Australia.
Mark E
ME
Howard
D000328:Adult; D001315:Australia; D001334:Automobile Driving; D001767:Blinking / Q000502:physiology*; D003198:Computer Simulation; D005143:Eyelids / Q000502:physiology; D006801:Humans; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D012892:Sleep Deprivation / Q000503:physiopathology*; D012894:Sleep Stages / Q000502:physiology*; D013997:Time Factors
automated devices; averaged data; drowsiness; eyelid closure episodes; professional drivers; sleepiness