Facial skin temperature as a biomarker for motion sickness.

Motion sickness may prevent the adoption of automated vehicles, as passengers are more susceptible than drivers. Predicting individual susceptibility from vehicle motion is challenging due high variability between people. There is a need to measure passengers' motion sickness, preferably objectively and unobtrusively. Biomarkers, the physiological responses to motion sickness, could provide a solution. We developed and evaluated a camera-based system using electro-optical and infrared imaging to measure facial skin temperature unobtrusively. The relationship between facial skin temperature in different regions of the face and motion sickness was determined by exposing participants (n = 14) to off-vertical axis rotation, which elicited severe nausea symptoms for most participants. While temporal patterns differed between participants, subjective ratings of motion sickness were specifically and consistently inverse-related to forehead skin temperature. The potential and challenges of using infrared cameras to objectively and unobtrusively assess motion sickness during autonomous driving are discussed.