title: Evaluation of eye metrics as a detector of fatigue.
abstract: OBJECTIVE
  This study evaluated oculometrics as a detector of fatigue in Air Force-relevant tasks after sleep deprivation. Using the metrics of total eye closure duration (PERCLOS) and approximate entropy (ApEn), the relation between these eye metrics and fatigue-induced performance decrements was investigated.
  
  
  BACKGROUND
  One damaging effect to the successful outcome of operational military missions is that attributed to sleep deprivation-induced fatigue. Consequently, there is interest in the development of reliable monitoring devices that can assess when an operator is overly fatigued.
  
  
  METHODS
  Ten civilian participants volunteered to serve in this study. Each was trained on three performance tasks: target identification, unmanned aerial vehicle landing, and the psychomotor vigilance task (PVT). Experimental testing began after 14 hr awake and continued every 2 hr until 28 hr of sleep deprivation was reached.
  
  
  RESULTS
  Performance on the PVT and target identification tasks declined significantly as the level of sleep deprivation increased.These performance declines were paralleled more closely by changes in the ApEn compared to the PERCLOS measure.
  
  
  CONCLUSIONS
  The results provide evidence that the ApEn eye metric can be used to detect fatigue in relevant military aviation tasks.
  
  
  CONCLUSIONS
  Military and commercial operators could benefit from an alertness monitoring device.
authors: Air Force Research Laboratory, 2215 First Street, Building 33, Wright-Patterson AFB, OH 45433, USA. Andy.McKinley@wpafb.af.mil
authors: R Andy
authors: RA
authors: McKinley
authors: Lindsey K
authors: LK
authors: McIntire
authors: Regina
authors: R
authors: Schmidt
authors: Daniel W
authors: DW
authors: Repperger
authors: John A
authors: JA
authors: Caldwell
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001359:Aviation; D053483:Eye Movement Measurements; D005221:Fatigue / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology*; D012892:Sleep Deprivation / Q000503:physiopathology*; D055815:Young Adult