Measuring Blood Alcohol Levels Through The Ears

A new device that fits over a person’s ears can measure real-time changes in blood alcohol levels through the skin.

AsianScientist (Nov. 23, 2021) – Getting pulled over for a blood alcohol test is never fun—more so in the time of COVID-19—where you would have to take off your mask and blow into a breathalyzer, a hand-held device that measures blood alcohol levels in your breath. Thankfully, there may soon be an alternative to breath-based blood alcohol tests: a new device that fits over a person’s ears like a pair of earmuffs or headphones.

In a proof-of-principle study published in Scientific Reports, a team led by Professor Mitsubayashi Kohji of the Tokyo Medical and Dental University’s Institute of Biomaterials and Bioengineering demonstrated how such a device can non-invasively measure real-time changes in blood alcohol levels through the skin.

Their device, a pair of commercial earmuffs modified to collect gas released through the skin of a person’s ears, works by using a sensor that detects ethanol vapor and releases light with varying intensity depending on ethanol concentration.

Kohji and his colleagues used their device to continuously monitor ethanol vapor released through the ears of three male volunteers, each of whom had consumed alcohol with a concentration of 0.4 g per kg body weight, for 140 minutes. At the same time, the team also measured the alcohol levels in the volunteers’ breath.

The researchers observed that changes in the concentration of ethanol released through the ears and breath were similar over time. As ethanol concentrations in the breath and blood are correlated, this was strong support for the device’s potential to replace a breathalyzer in estimating blood alcohol levels.

While previous non-invasive blood alcohol measuring devices have used the hand as a target, sweat and thicker skin can get in the way of accurate measurements. Kohji’s findings suggest that the ears may be a more suitable instead.

In addition to producing less sweat, the average highest concentration of ethanol released through the ears was 148 parts per billion, double the concentration previously reported to be released through the skin of the hand.

The researchers also propose that the device can be modified to measure other gases released through the skin, allowing it to be used for other purposes beyond blood alcohol tests.

“Using this versatility, we will further investigate external ear-derived VOCs for non-invasive and real-time assessment of metabolisms and disease screening,” they wrote.

The article can be found at: Toma et al. (2021) External Ears for Non-invasive and Stable Monitoring of Volatile Organic Compounds in Human Blood.


Source: Tokyo Medical and Dental University; Photo: Shutterstock.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

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