Checking alcohol content in the body can reveal how much a person is intoxicated. Most famously, the police use breath analysis to weed out drunk drivers who endanger themselves and others on the road. While researchers have been working on creating other non-invasive devices that can achieve this result, a team from Japan has successfully done this using an unassuming piece of headwear – earmuffs –attached to a biosensor (or a bio-sniffer).
The researchers designed these earmuffs to detect gaseous ethanol, a volatile organic compound (VOC) that emanates from blood after the body metabolizes alcohol. On detection, the earmuffs light up the light’s intensity reflecting the amount of alcohol they detect.
According to Kohji Mitsubayashi and team, collecting gas over ears ensures accurate assessment as there is less interference from sweat. It also solves complications in breath analysis which require specific end-tidal air from the lungs to accurately depict ethanol concentration. The ears also emanate VOCs “unconsciously and continuously”, reducing effort for both the analyzer and the wearer.
The “Earmuffs Test”
To check the device’s efficacy, the team tested it on three male participants. After testing their base ethanol levels for 10 minutes, the participants were asked to drink alcohol with a concentration of 0.4 grams per kilogram, while the researchers measured the device’s output for 140 minutes.
To compare, the authors measured ethanol levels using a breath analyzer. They also used a device with reagents that change color when exposed to ethanol in sweat.
Through this test, the authors confirmed that the earmuffs had similar efficacy in detecting ethanol as the established breath test. This proves that the device can be successfully used as a non-invasive alternative to a breath analyzer, which requires a tube inserted into the mouth.
They also found that the average highest concentration of ethanol the ears emanated was around 148 parts per billion. The skin of the hands only released half of that.
In the manuscript, the authors write: “The monitoring system is potentially applicable to other VOCs b[y] changing an enzyme. Using this versatility, we will further investigate external ear-derived VOCs for non-invasive and real-time assessment of metabolisms and disease screening”.