This device is based on a commercially available headset that fits the human ear, and has been improved to collect gas released from the skin of the ear and to provide the function of an ethanol vapor sensor.When the ethanol vapor emitted from the ear is detected, the sensor emits light, and the ethanol concentration can be calculated from the intensity of the light.

　In a recent proof-of-principle study, the device was used to continuously monitor the ethanol vapor released from the ears of three male subjects who ingested 1 grams of alcohol per kilogram of body weight for 0.4 minutes.As a result, the changes over time in the concentrations of "ethanol released from the ear" detected by this device and "ethanol contained in exhaled breath" measured by another sensor and device are similar in all subjects. Turned out.Previous studies have shown that breath ethanol levels correlate with blood ethanol levels, and this new device can be used in place of a breathalyzer to assess blood alcohol levels through the skin in real time. It was shown that it can be done.

　In the conventional device, the blood alcohol concentration was measured by using a hand instead of the exhaled breath as a method of measuring the low invasiveness without the need to insert a tube into the mouth. We have succeeded in detecting ethanol with an average maximum concentration of 2 ppb from the ear, which is twice the concentration of ethanol released from the skin of the hands reported so far.Therefore, the ear is considered to be a more appropriate measurement site than the hand.

　In addition, this device has the potential to be applied to disease screening tests by measuring other transdermal gases.

Paper information:[Scientific Reports] External ears for non-invasive and stable monitoring of volatile organic compounds in human blood