In an effort to improve upon existing alcohol biosensor technology, the National Institute on Alcohol Abuse and Alcoholism (NIAAA) recently held a competition to design a wearable, discreet device capable of measuring blood alcohol levels in close to real-time, which will help to advance the mission of the NIAAA in the arenas of research, treatment and rehabilitation.

The recipient of the $200,000 first prize of the Wearable Alcohol Biosensor Challenge was BACtrack, a San Francisco-based company that makes portable breath alcohol testers.  Their winning entry, named BACtrack Skyn, is worn on the wrist and measures blood alcohol content (BAC) through sweat. Transdermal monitoring, through an electrochemical sensor, tracks the ethanol molecules that are released through the skin when alcohol is consumed. The ethanol signal is then converted into a BAC reading which is sent via Bluetooth to a smartphone to store the data. Readings can be taken every second, and can be sent from the wrist device to a smartphone or cloud.

While breathalyzers for personal use can be purchased for under $100, current portable breath alcohol testers (PBTs) used for legal and criminal justice purposes can cost upwards of $1,000. BACtrack devices are expected to cost a fraction of that, but since they cannot provide real-time blood alcohol levels, they will not become a substitute for PBTs. BACtrack monitors take around 45 minutes to take an accurate reading since that is approximately how long it takes for ethanol to be transmitted through the skin.

The benefit of the new wrist monitor is that it can continually and discreetly measure BAC and provide a history to the wearer. It will also be useful for the alcohol research community since it can reliably track and monitor BAC levels, helping to gather data for substance use treatment and research. By providing an objective measure of alcohol consumption it will decrease reliance on self-report, which can be less accurate.

The device also has personal applications. Smartphone integration can notify users who are approaching an undesired BAC level and want to slow down or stop drinking. A family member could be notified if BAC goes above 0%. The monitor can create an objective record of drinking history, without the confounding effects of self-report, and this information can be shared with a doctor or therapist.

The device, expected to be on the market in late 2016, has not yet been submitted to the Food and Drug Administration for marketing approval.