title: Association of Subjective and Interpretive Drowsiness with Facial Dynamic Changes in Simulator Driving.
abstract: BACKGROUND
  Major injuries and death in accidents have roots in drowsiness. Sleepiness is a main result of insufficient sleep. It is vital to explore drowsiness and its level. There are various sorts of methods in the forms of subjective and objective approaches. The goal of this study was to detect the association of subjective and interpretive drowsiness with facial dynamic changes.
  
  
  METHODS
  This experimental study was conducted in the Virtual Reality Lab, in Khaje-Nasir Toosi University of Technology, Tehran Iran on 40 drivers in 2015. Facial dynamic changes (eyes, mouth and eyebrows), Karolinska Sleepiness Scale (KSS) and Observer Rating of Drowsiness (ORD) were applied. The neural network and Viola-Jones were utilized for facial characteristics detection. Statistical analyses were conducted using SPSS version 21.
  
  
  RESULTS
  Thirty-four drivers got drowsy during the test. They were selected randomly among suburban drivers at the age in a range of 26 to 60 yr old. Descriptive statistics of the dynamic changes in eyebrows, mouth and eyes showed that these features were of meaningful changes with respect to the level of drowsiness during driving. A relationship between the dynamic changes of facial features and ORD was recognized. Moreover, there was a significant relationship between facial expression and drowsiness (P<0.05).
  
  
  CONCLUSIONS
  Results of KSS and ORD illustrated that there were dynamic changes in eyes and mouth and eyebrow parameters while driver felt sleepy. This research is helpful in a way that specific changes in elements of face could be effective to provide tools to predict drowsiness.
authors.affiliation: Department of Occupational Health, School of Public Health, International Campus Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Karchani
authors.affiliation: Department of Occupational Health, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Adel
authors.initials: A
authors.lastname: Mazloumi
authors.affiliation: Department of Occupational Health, School of Public Health, International Campus Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Gebraeil
authors.initials: G
authors.lastname: NaslSaraji
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Arash
authors.initials: A
authors.lastname: Akbarzadeh
authors.affiliation: Department of Mechatronics, Faculty of Engineering, Islamic Azad University South Tehran Branch, Tehran, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Niknezhad
authors.affiliation: Department of Occupational Health, School of Public Health, Shahroud University of Medical Sciences, Shahroud, Iran.
authors.forename: Mohammad Hossien
authors.initials: MH
authors.lastname: Ebrahimi
authors.affiliation: Department of Biostatistics, School of Health, Kermanshah University of Medical Sciences, Kermanshah, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Raei
authors.affiliation: Department of Ergonomics, Faculty of Health, Work Health Research Centre, Qom University of Medical Sciences- Qom, Iran. mkhandan@muq.ac.ir.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Khandan
mesh_terms: D000328:Adult; D001334:Automobile Driving; D005149:Facial Expression; D005260:Female; D006801:Humans; D007492:Iran; D008297:Male; D008875:Middle Aged; D012892:Sleep Deprivation / Q000175:diagnosis*; D012894:Sleep Stages / Q000502:physiology*; D011795:Surveys and Questionnaires
keywords: Drowsiness; Facial dynamic changes; Karolinska Sleepiness Scale; Observer Rating of Drowsiness; Simulator driving