Remote Photoplethysmography: Evaluation of Contactless Heart Rate Measurement in an Information Systems Setting

As a source of valuable information about a person’s affective state, heart rate data has the potential to improve both understanding and experience of human-computer interaction. Conventional methods for measuring heart rate use skin contact methods, where a measuring device must be worn by the user. In an Information Systems setting, a contactless approach without interference in the user’s natural environment could prove to be advantageous. We develop an application that fulfilsthese con-ditions. The algorithm is based on remote photoplethysmography, taking advantage of the slight skin color variation that occurs periodically with the user’s pulse. When eval-uating this application in an Information Systems setting with various arousal levels and naturally moving subjects, we achieve an average root mean square error of 7.32 bpm for the best performing configuration. We find that a higher frame rate yields better results than a larger size of the moving measurement window. Regarding algo-rithm specifics, we find that a more detailed algorithm using the three RGB signals slightly outperforms a simple algorithm using only the green signal.