Data from accelerometers – sensors found in most current cell phones that detect a person’s footsteps – can be used to determine if its owner is under the influence of alcohol and has exceeded the permitted BAC for driving.
A study carried out by the universities of Stanford and Pittsburgh (United States) used 22 volunteers who were given a dose of vodka sufficient to produce an amount of alcohol aspirated in air of 0.2% concentration in blood – in the United States it is used a different system, with a limit allowed to drive of 0.08%.
Subsequently, they asked people to walk ten steps in a straight line and turn around and take another ten steps. The study analyzed the data obtained by the accelerometer of their mobile devices – which were placed in the lumbar region – during the next seven hours.
Using accelerometer data, the researchers were able to determine with 92.5% accuracy when a person had a blood alcohol level greater than 0.08% Trr, and therefore exceeded the amount allowed for driving.
The two most determining data to discern if a person has consumed alcohol through the mobile phone and the accelerometer are the amplitude of the signal and the variance of the ‘x’ axis, that is, the sway when walking, according to the research, published this Tuesday in the Journal of Studies on Alcohol and Drugs.