Clinical evaluation of a novel interstitial fluid sensor system for remote continuous alcohol monitoring

This study describes the functioning of a novel sensor that measures the alcohol concentration in the interstitial fluid (ISF) of a human subject. ISF is extracted using vacuum pressure from micropores on the stratum corneum layer of the skin. The pores are created by focusing a near infrared laser on a layer of black die attached to the skin. This poration procedure is essentially painless. Clinical studies show that the sensor readings are correlated with alcohol levels in blood and collected using a breathalyzer. Alcohol could be detected in the subject's ISF within 15 min of the first oral intake of alcohol. Tests in a laboratory setup show that the sensor exhibits a linear response to alcohol concentrations in the range 0%-0.2%. The sensor is minimally invasive and alcohol monitoring using the sensor was shown to continue even when the subject is asleep. The sensor is viable for approximately three days after skin poration. The sensor is interfaced to a wireless health monitoring system that transfers sensor data over existing wide-area networks such as the Internet and a cellular phone network to enable real-time remote monitoring of subjects.