Smartphones will be determining weather you are drunk.

Soon smartphones will be able to tell if someone is drunk based on their gait, even if the phone user doesn't know.

Brian Suffoletto, now at Stanford University in California, and his colleagues at the University of Pittsburgh in Pennsylvania, wanted to see if they could take advantage of the accelerometers built into most smartphones to detect changes in walking habits that occur when the people are drunk. . .

Suffoletto and his team recruited 22 volunteers and gave each one an hour to consume a drink mixed with enough vodka to produce an alcohol concentration in the air of 0.2%, well above the legal limit of driving in the US from 0.08. They then strapped a smartphone to each participant's lower back. Every hour for the next 7 hours, the volunteers were given a breathalyzer test, then asked to walk in a straight line for 10 paces, turn around, then back up 10 paces.

More than 90% of the time, researchers could use a person's gait changes, measured by their smartphone's accelerometer, to accurately predict when the concentration of alcohol in exhaled air exceeded 0.08%. hundred.

Suffoletto says the next step will be to determine whether similar precision is possible when the phone is placed in different positions, such as when held in the hand or in a pocket.

“It can be used by people who want a warning when they show signs of disability,” says Suffoletto. Previous research by his team found that people don't realize they're injured up to 50% of the time when they're drunk. “It can alert a person who doesn't recognize their disability and prevent them from driving when [drunk],” he says.

Since data relating to the use of smartphones and sensors, including accelerometers, is widely collected, third parties may collect this information to try to determine if a smartphone user is drunk, Suffoletto explains.

“If someone wanted to make an effort to process and analyze it, they could probably draw some conclusions about the changes in walking patterns,” he says. However, Suffoletto assures us that without further proof, "it would be a leap" to conclude that someone has been intoxicated by their own walking.