Publications

As with any research and development effort, the DADSS Research Program has published findings throughout the process. In the links below, you can access these articles and research papers, published from 2009 through the present.

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Unobtrusive Breath Alcohol Sensing System

Proceedings of the 24th International Technical Conference on the Enhance Safety of Vehicles.
Paper Number 15–0458
Publication Year: 2015

Although the vast majority of vehicle drivers are sober, drunk driving remains to be a major contributor to fatal accidents. Massive deployment of unobtrusive breath alcohol sensing systems could potentially save tens of thousands of lives worldwide every year by preventing drunk driving [1]. The work reported here is ultimately aiming at such a system. The technical performance of the present sensing system with respect to automotive requirements is summarized, and new results towards unobtrusive breath alcohol determination within vehicle compartments are presented.

Breath alcohol concentration (BrAC) can be determined unobtrusively if (i) the sensing system provides real-time signals with adequate accuracy corresponding to the local concentrations of both alcohol and a tracer gas, e g CO2, (ii) the dilution of the breath is not excessive in relation to background concentrations, (iii) the sensor location can be seamlessly integrated into the interior of a vehicle cabin. All three of these aspects are addressed in the present paper.

More than a hundred prototypes based on infrared spectroscopy were fabricated and subjected to automotive qualification tests in the full temperature range -40 … +85⁰C. In the majority of tests, adequate performance was noted. Measures are now being taken to fill remaining performance gaps. Test results with human subjects were positive and in accordance with expectations with respect to physiological variations. In-vehicle tests showed that for the best sensor position, passive breath samples allowed BrAC to be determined at a resolution of 2-4% of the US legal limit, providing proof-of-principle for unobtrusive testing. Nevertheless, vehicle integration remains to be the major technological challenge to the objective of deployment on a large scale of unobtrusive driver breath alcohol determination.

The feasibility of unobtrusive breath alcohol determination in vehicles, and adequate performance of a sensor system based on infrared spectroscopy have been experimentally demonstrated. The alcohol sensing system may advantageously be integrated into vehicles, and may also be combined with other technologies to monitor driver impairment.

Unobtrusive and Highly Accurate Breath Alcohol Analysis Enabled by Improved Methodology and Technology

Journal of Forensic Investigation
Publication Year: 2014

The study objective was to evaluate a novel method and technology for unobtrusive determination of breath alcohol in relation to current industrial accuracy standards. The methodology uses carbon dioxide as a tracer gas detected by sensor technology based on infrared spectroscopy. Part one of the investigation was to analyse the performance of hand-held prototype devices and included tests of resolution, unit-to-unit variation during calibration, response to alcohol containing gas pulses created with a wet gas simulator, and cross sensitivity to other substances. In part two of the study, 30 human participants provided 1465 breath tests in both unobtrusive and obtrusive use modes. The results of both parts of the study indicate that the prototype devices exceeded present industrial accuracy requirements. The proposed methodology and technology eliminate the previous contradiction between unobtrusiveness and high accuracy.

Critical Performance of a New Breath Alcohol Analyzer for Screening Applications

Intelligent Sensors, Sensor Networks and Information Processing (ISSNIP), 2014 IEEE Ninth International Conference
Publication Year: 2014

In screening applications there is a need for improved breath alcohol analyzers. Accuracy, specificity, usability, and through-put are critical to the device performance. Objective: To characterize the critical performance of a new contactless breath alcohol analyzer. Methods: The device is characterized by measurements using artificial breath gas and human subjects. Breath sampling is performed in ambient air using carbon dioxide as a biomarker. Results: Resolution and inter-individual variation, response time, and specificity were shown to meet the requirements of industrial standards. The feasibility of contactless measurement was demonstrated. Conclusions: The new device exhibits sufficient performance in moderately diluted breath samples. Further work is underway to reach the objective of unobtrusive breath alcohol analysis.

Unobtrusive breath testing

International Conference on Alcohol, Drugs and Traffic Safety, ICADTS 2013
Publication Year: 2013

Background Breath testing today requires cooperation, significant physical effort, and is time-consuming. In order to reach an increased acceptance for general breath testing among drivers and professionals whose sobriety is of importance for a safe work environment, a less obtrusive breath testing procedure is desirable.

Aim The aim has been to develop a breath alcohol analyser enabling fast, simple contact free breath testing with less physical effort. The sensor should meet the automotive industry’s requirements of long-time stability, and short start-up and response time, regardless of the ambient temperature. The long term goal is extensive implementation of an in-vehicle integrated unobtrusive alcohol detection system.

Results The physiological rationale of the use of CO2 as a tracer gas has been investigated, and a new non-dispersive infrared gas senor enabling measurements of both breath alcohol and expired CO2 have been developed. The gas sensor has been evaluated with excellent results in sensitivity, cross-sensitivity. In a controlled drinking study a strong correlation (r=0.95) was found between reference tests and tests performed from a distance of a few centimetres with the new sensor. As proof-of-principle of unobtrusive breath testing we have now shown detection of normal human mouth and nose breathing, and artificial gas pulses containing alcohol from a distance over 60 cm in a vehicle compartment.

Future To improve sampling of the driver’s breath, future work focuses on optimised signal acquisition and selection of positions within the vehicle compartment. Present challenges and important input to this work will be the influence from external air flows (ventilation), difference in breathing pattern (mouth/nose), passengers, and e.g. wind shield fluid. The sensor also provides possibilities to other applications, e.g. for access and passage control.

Alcohol-Impaired Driving in the United States: Contributors to the Problem and Effective Countermeasures

Traffic Injury Prevention
Publication Year: 2012

Objective: To review the effectiveness of current countermeasures in alcohol-impaired driving.

Method: This article provides an overview of the contributors to the alcohol-impaired driving problem in the United States and reviews the effectiveness of alcohol-impaired driving countermeasures.

Results: Many effective countermeasures have been used during the past few decades both to deter drivers from driving when they are over the legal limit for alcohol and to discourage driving while intoxicated (DWI) offenders from reoffending once they have been caught and convicted. In recent years, greater attention has been given to the problem of “hardcore” drinking drivers, a term coined to refer to those who repeatedly drive with high blood alcohol concentrations and are resistant to changing their behavior. Although such individuals are a legitimate target for attention, focusing predominantly on this group will result in missed opportunities to address a large portion of alcohol-impaired driving crashes. This article provides a review of the primary countermeasures that have been used to reduce alcohol-impaired driving and summarizes evidence for their effectiveness. It asks the question of where, in an environment of limited resources, attention should be focused.

Conclusions: General deterrent approaches, such as frequent and highly publicized sobriety checkpoints, have the greatest potential to save lives and should be the mainstay of state and local efforts. Specific deterrent approaches, aimed at deterring DWI offenders from reoffending, such as alcohol ignition interlocks, should be applied to all apprehended drivers, whatever their drinking history. Evidence suggests that they could benefit from them. In the future, advanced in-vehicle technologies that would prevent vehicles from being driven when their drivers are over the legal limit may hold the key to drastically reducing the alcohol-impaired driving problem.