Development of a New Breath Alcohol Detector without Mouthpiece to Prevent Drunk Driving

Breath alcohol interlock systems are used in Europe and the U.S. for drunk driving offenders, and a certain effect has been revealed in the prevention of drunk driving. Nevertheless, problems remain to be solved with commercialized detectors, i.e., a person taking the breath alcohol test must strongly expire to the alcohol detector through a mouthpiece for every test, more over the determination of the breath alcohol concentration requires more than 5 seconds. The goal of this research is to develop a device that functions suitable and unobtrusive enough as the interlock system. For this purpose, a new alcohol detector, which does not require a long and hard blowing to the detector through a mouthpiece, has been investigated. In this paper, as a tool available on board, a contact free alcohol detector for the prevention of drunk driving has been developed. The detector doesn’t require a mouthpiece for the detection because driver’s breathe sample is captured by an electric suction fan of the detector. The influence of fluctuations of the alcohol sensor signals caused by air mixing are extremely reduced by the calibration of alcohol concentration using an oxygen level of driver’s expired breath that is measured simultaneously with the alcohol content. The detector is able to measure breath alcohol concentration rapidly and easily, compared with the current breath alcohol detectors, which require a blowing through a mouthpiece. Good accuracy has been demonstrated in an experiment with the drunk subjects.