Your phone sits there in your pocket ready to give you directions to the best pizza joint in North Central Texas – and ready, too, to keep track of your calorie intake and fitness level. Your phone is ready to help you keep appointments, and also to help you while away the hours reading books, watching movies or playing games. Your phone is with you all the time, always ready to help with nearly every aspect of your life.
Add one more to the list of things your phone can do for you: determine if you’re impaired by alcohol and help you to avoid being arrested for drunk driving.
That’s according to new a study published in the Journal of Studies on Alcohol and Drugs. Researchers say they’re able to use the powerful sensors and processors in smartphones to determine when people are drunk, based solely on measurements of changes in the way they walk.
Researchers first recruited a group of 22 volunteers, ages 21 to 43. Each of them was weighed and then given weight-based vodka cocktails custom mixed to achieve in each participant a blood-alcohol content (BAC) of .20. (Note: in Texas, the legal threshold for driving while intoxicated (DWI) is a BAC of .08 percent.)
The volunteers had 60 minutes in which to consume their powerful mixed drinks. Researchers then secured a smartphone to each volunteer’s lower back with an elastic band and asked the participants to perform a simple walking exercise reminiscent of a field sobriety test.
Every hour over a 7-hour period, volunteers would walk 10 steps in a straight line, turn, and walk 10 steps back.
The phones measured and analyzed each volunteer’s movement forward and backward, side-to-side and up and down. Researchers said the phones were remarkably accurate: 90 percent of the time, they correctly determined when participants were legally intoxicated (with at least a .08 BAC) solely by measuring changes in gait.
In a statement accompanying the study, researchers said “we found preliminary evidence supporting use of gait-related features measured by smartphone accelerometer sensors to detect alcohol intoxication.”
The study’s lead author said future research will determine if phones can be just as accurate when they’re held in hands or carried in pockets.
In the near future, your phone will be able to determine that you’ve had too much to drink, alert you, and help you to avoid the harsh punishments of Texas drunk driving laws.