Connections between physical objects, like devices, buildings or vehicles that are embedded with electronic sensors to collect and analyse data in real-time and/or communicate them to other devices are known as the Internet of Things. A report in the current issue of Nature now introduces a wearable device that monitors a number of physiological parameters measured from sweat from indivudial humans. The authors mixed commercially available integrated circuit (IC) technologies with a plastic wristband by printing a flexible ciruit board onto the band. Among the measured variables are the body temperature and glucose, lactate, sodium as well as potassium levels, which allow an understanding of the individuals physiological state.

The performance of each sensor on the band was evaluated using different solutions. Since some sensors are driven by enzymatic reactions, the temperature has an effect on sensor activity. To compensate in real-time for the influence of temperature, the authors used a built-in analog to digital converter and a microcontroller which simultaneously transmits data via bluetooth to a users interface on a phone. Experiments were performed to ensure the fidelity of the sensor readings from a stationary cycling and a group outdoor running experiment and validated with off-body analysis from collected sweat.

The platform, as described by the authors, could be used or reconfigured for other biomarkers within sweat to perform personalized and real-time physiological investigations. Further more, huge amounts of data could be collected in larger studies and analysed with current data mining techniques. Predictive algorithms could then use this data to monitor the health status and clinical needs of individuals and society.

Wei Gao, Sam Emaminejad, Hnin Yin Yin Nyein, Samyuktha Challa, Kevin Chen, Austin Peck, Hossain M. Fahad, Hiroki Ota, Hiroshi Shiraki, Daisuke Kiriya, Der-Hsien Lien, George A. Brooks, Ronald W. Davis and Ali Javey. Fully integrated wearable sensor arrays for multiplexed in situ perspiration analysis. Nature (2016), doi: 10.1038/nature16521 weblink