Portable Alcohol Detection System for Driver Monitoring

A portable alcohol detection system based on exhaled breath analysis has been developed. The system consists of a breath sensor unit, a smartphone to control the sensor unit and communicate various data, and a data cloud system. The detection system can be used to monitor a driver's status from a remote location. The breath sensor unit consists of four separate sensors. The first is a water vapor sensor that is used to verify if the applied gas is human breath. The others are semiconductor gas sensors to detect ethanol, acetaldehyde, and hydrogen, respectively. The sensors are part of a detector that is connected to a smartphone, and the driver's alcohol check results and interview data for health are automatically sent to a data cloud system. The ethanol concentration is obtained from the voltages of the three semiconductor gas sensors. From our field tests, in which we obtained data from more than 30 sensor units, we investigated the performance of exhaled breath recognition. When the field test users of our detector did not consume alcohol, their ethanol, acetaldehyde, and hydrogen concentration levels, as a result of natural human metabolism, were 1.8, 1.9, and 0.1 ppm on average, respectively.