Your smartphone knows if you’re drunk
In the short time that smartphone technology has existed, it has become deeply ingrained in every aspect of our daily lives. Our biology is no exception.
Smart devices are now used to measure everything from your heart rate and exercise patterns to the amount of oxygen in your blood. Even today, new applications are starting to blur the line where technology ends and biology begins.
One such application: predicting whether or not you’re drunk with prescient accuracy.
Have you ever turned your smartphone on its side and watched it switch the orientation of the screen automatically? Most of you probably have. For this trick, you can thank a tiny sensor in your smartphone known as an accelerometer. Essentially, It measures when your device accelerates in a new direction so that the device can be aware of its position.
Scientists now say that the same sensor technology in use for years is sensitive enough to evaluate how you’re walking at a given moment and prove that you’re intoxicated.
Enter Drunk Science
From previous academic studies, we know that up to 1 in 2 people fail to accurately recognize the point at which they are too intoxicated to drive. Armed with this knowledge, six doctors and researchers at Stanford University and the University of Pittsburgh began to investigate smartphone technology and the possibility that it could be used as an automated intervention tool when you are at risk of drunk driving or relapsing from alcohol treatment.
The researchers quickly zeroed in on our old friend, the humble accelerator. Study subjects first had smartphones strapped to their lower backs. They were then told to walk 10 steps forward, turn around, and walk 10 steps back to establish a baseline for the way they walked while not intoxicated.
Then the test subjects were given heavy amounts of vodka – enough to achieve more than twice the blood alcohol concentration required for police to establish drunk driving in most states – and asked to walk the same steps again.
The researchers then compared the difference between the intoxicated and non-intoxicated gaits.
“We really wanted to have enough data points over the threshold of the legal limit of alcohol, which is 0.08,” one researcher told Wired this month. “If you’re giving them a lower dose, you may only get one or two time points before the body sort of metabolizes the alcohol.
“ … Now you’ve got an objective tool. If we’re good enough, we can actually refine it, so that we can estimate what the blood alcohol content is just by their gait signatures.”
As it turns out, the old saying about being stumbling drunk is more insightful than we thought. The smartphone in the test could predict whether a subject was intoxicated with 93% accuracy. Will the smartphone of tomorrow prevent you from starting your car if you’re drunk? Probably not. At least, the researchers who created the study don’t see it that way. They see it as a possible critical tool for early intervention before bad decision-making takes place – like texting your ex.