Towards a capacitively coupled electrocardiography system for car seat integration

Driver monitoring is one of the key issues to increase safety and comfort in future cars. Biomedical engineering offers diverse monitoring methods possibly useful in automotive applications. One of the monitoring modalities clearly is the detection of heart rhythm of the driver, which should not be performed based on wired systems. Here we present preliminary work and a feasibility study to integrate capacitively coupled electrocardiography (CCECG) into the seat of a standard upper-class car to measure heart rate and derive state information about the occupant. Modular CCECG sensors are implemented to examine the performance of various shapes and sizes of capacitive electrodes with the same electronic circuit. To enhance performance of the sensors, techniques like capacitance change compensation, guarding and driven seat circuit are applied. An analysis is done to find an appropriate place to install the sensors into the car seat. For comparison, measurements with and without seat cover are considered. Eventually, influences of different seat functions near real world appliances on the CCECG results are evaluated.