An Experiment to Non-Intrusively Collect Physiological Parameters towards Driver State Detection

Acquiring drivers’ physiological parameters is helpful for driver assistance systems to reliably estimate drivers’ comprehensive mental states, but traditional methods of measurements have to intrusively attach sensors or fasten electrodes to the body. Intrusive methods of measurement are acceptable in experimental settings but unacceptable as routine operation in daily driving. In this paper, the Smart Wheel System is introduced. The Smart Wheel System is a prototype system that collects the following cognition/emotion physiological signals: blood volume pulse, skin conductance, skin temperature, and respiration wave. It uses embedded sensors and electrodes in steering wheel and seat belt with near-zero interference. Due to the fact that hand and body movements cause temporary gap in the real-time data stream, gripping force and gripping position are collected as indicative data to compensate breaks in the physiological data stream. In the current experiments, FlexComp biofeedback system is used as a standard test instrument to verify the performance of the Smart Wheel System. The correlations between the Smart Wheel System and the FlexComp measurements range from 0.85 to 0.96. The average measurement errors range from −6% to 10%. The results show that the Smart Wheel System can be used to provide good real-time physiological parameters for onboard intelligent systems to monitor driver mental states non-intrusively.