Useful, necessary and also sneaky. Mobile phones are something they always carry with them. They are created for that and for much more, and they are pieces of technology so cutting-edge that they can even serve as a kind of improvised safety breathalyzer test to find out who has too many glasses on their body.
No, it is not about blowing the mic – although we have already seen examples of this -, but it is easier: Simply by the way you walk. Hint: the secret is in the accelerometers
Breathalyzer and mobile
A joint team from the universities of Stanford and Pittsburgh (United States) has carried out an experiment to determine whether the data collected by the accelerometers of a smart mobile phone can be used reliably to indicate that the person carrying that mobile is not in conditions of driving a car.
The study, which used 22 volunteers, provided them with a dose of vodka sufficient to produce an amount of alcohol aspirated in air of 0.2% concentration in the blood ”- in the United States a different system is used, with a permitted limit to drive 0.08%. After ‘cheering them up’ a bit, those responsible for the study asked people to walk a total of 10 steps in a straight line and turn around and walk another 10 steps. The study analyzed the data obtained by the accelerometer of their mobile devices – which were placed in the lumbar region – during the next 7 hours.
Almost 100% effective
What happened? That the research team was enormously successful, since using the data collected by the accelerometers, the researchers were able to determine with 92.5% accuracy when a person had a blood alcohol level greater than 0.08% , and therefore exceeded the amount allowed to drive.
But how does this work? What data and what reading is made of them? The two most determining data to discern whether a person has consumed alcohol through the mobile phone and the accelerometer are:
– The amplitude of the signal
– The variance of the ‘x’ axis (the rocking when walking)
According to the research, published this week in the Journal of Studies on Alcohol and Drugs, these data could be used to alert people that they are not in a position to drive if they exceed the limit allowed by law, since “50 % of people are not aware of when they have drunk more than the legal rate ”, according to the authors in the New Scientist.