Mid Sweden University

Can one technical solution help prevent drowsy drivers and detect a child left behind? Yes, using a single, maintenance-free, Non-Dispersive Infrared (NDIR) gas sensor integrated in the cabin ventilation system. Carbon dioxide (CO2) is an established proxy for ventilation needs in buildings. Recently, several studies have been published showing a moderate elevation of the indoor carbon dioxide level effect cognitive performance such as information usage, activity, focus and crisis response. A study of airplane pilots using 3-hour flight simulation tests, showed pilots made 50% more mistakes when exposed to 2,500 ppm carbon dioxide compared to 700 ppm. This has a direct impact on safety. All living animals and humans exhale carbon dioxide. In our investigations we have found that an unintentionally left behind child, or pet, can easily be detected in a parked car by analyzing the carbon dioxide trends in the cabin. Even an 8-month old baby acts as a carbon dioxide source, increasing cabin CO2 levels at a 20ppm/minute rate allowing for detection within one minute. Vehicles running with the ventilation system in recirculation mode normally reach above the fresh air limit of 1,000 ppm within a few minutes. The carbon dioxide level normally stabilizes between 3,000 and 10,000 ppm. Levels that will make the driver drowsy, reducing their cognitive performance and impact safety. Using an NDIR gas sensor in the ventilation system will reduce driver performance degradation due to elevated carbon dioxide levels, allowing reliable detection of any unintentionally left behind children or pets, potentially saving lives. © 2020 SAE International. All Rights Reserved.