Non-contact video-based remote photoplethysmography for human stress detection

This paper presents the experimental results for stress index calculation using developed by the authors information technology for non-contact remote human heart rate variability (HRV) retrieval in various conditions from video stream using common wide spread web cameras with minimal frame resolution of 640x480 pixels at average frame rate of 25 frames per second. The developed system architecture based on remote photoplethysmography (rPPG) technology is overviewed including description of all its main components and processes involved in converting video stream of frames into valuable rPPG signal. Also, algorithm of RR-peaks detection and RR-intervals retrieval is described. It is capable to detect 99.3% of heart contractions from raw rPPG signal. The usecases of measuring stress index in a wide variety of situations starting with car and tractor drivers at work research and finishing with students passing exams are presented and analyzed in detail. The results of the experiments have shown that the rPPG system is capable of retrieving stress level that is in accordance with the feelings of experiments’ participants.

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Opracowanie rekordu ze środków MNiSW, umowa Nr 461252 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2020).