title: Remote detection of mental workload changes using cardiac parameters assessed with a low-cost webcam.
abstract: We introduce a new framework for detecting mental workload changes using video frames obtained from a low-cost webcam. Image processing in addition to a continuous wavelet transform filtering method were developed and applied to remove major artifacts and trends on raw webcam photoplethysmographic signals. The measurements are performed on human faces. To induce stress, we have employed a computerized and interactive Stroop color word test on a set composed by twelve participants. The electrodermal activity of the participants was recorded and compared to the mental workload curve assessed by merging two parameters derived from the pulse rate variability and photoplethysmographic amplitude fluctuations, which reflect peripheral vasoconstriction changes. The results exhibit strong correlation between the two measurement techniques. This study offers further support for the applicability of mental workload detection by remote and low-cost means, providing an alternative to conventional contact techniques.
authors.affiliation: Laboratoire de Conception, Optimisation et Modélisation des Systèmes (LCOMS), Université de Lorraine, Bâtiment ISEA (Institut Supérieur d׳Electronique et d׳Automatique), 7 rue Marconi, 57070 METZ Technopôle, France. Electronic address: frederic.bousefsaf@univ-lorraine.fr.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Bousefsaf
authors.affiliation: Laboratoire de Conception, Optimisation et Modélisation des Systèmes (LCOMS), Université de Lorraine, Bâtiment ISEA (Institut Supérieur d׳Electronique et d׳Automatique), 7 rue Marconi, 57070 METZ Technopôle, France.
authors.forename: Choubeila
authors.initials: C
authors.lastname: Maaoui
authors.affiliation: Laboratoire de Conception, Optimisation et Modélisation des Systèmes (LCOMS), Université de Lorraine, Bâtiment ISEA (Institut Supérieur d׳Electronique et d׳Automatique), 7 rue Marconi, 57070 METZ Technopôle, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Pruski
mesh_terms: D000328:Adult; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D020407:Internet; D008297:Male; D017156:Photoplethysmography; D012815:Signal Processing, Computer-Assisted; D013315:Stress, Psychological / Q000503:physiopathology*; D057190:Stroop Test; D014741:Video Recording / Q000379:methods*; D016526:Workload / Q000523:psychology*; D055815:Young Adult
keywords: Mental workload changes; Photoplethysmography; Pulse rate variability; Webcam