Investigation of Non-Contact Biometric System Using Capacitive Coupling Electrodes

Recently road accidents caused by drivers falling sleep has been increasing among other car accidents. Many studies report that drowsiness occurs during driving, and it is required to develop the driver drowsiness detection system. In this study, the authors use capacitive coupling electrode sensors that enable sensing the condition of a person while driving a car without physical constraints and even being unaware of the device. This paper explains about the measurement principles of capacitive coupling electrodes, the configuration of analog circuit, and a digital filter for $R$ wave detection algorithm using a microcomputer are described. Thereafter, experiments to prove the created system can measure the RR interval are described. Further, it is shown that the RR interval measured by the system is as accurate as a cardiograph equipment electrocardiograph.