Evaluation of an RF wearable device for non-invasive real-time hydration monitoring

In this paper, we validate a novel wearable device for real time non-invasive hydration monitoring. An experiment was carried out on three sets of 12 subjects under various exercise intensities to identify how the received signal strength indicator (RSSI) captured with the device relates to the change in the body hydration, body water loss percentage (BWL%). A linear regression correlation R2 of 0.77 and a third degree polynomials correlation (R2=0.83) between ΔRSSI and BWL% is established based on the observation of the experiment, which implies that the hydration status can be quantized as body water loss by measuring ΔRSSI. Therefore, the technique and device is verified to be a potentially solid solution for wearable non-invasive real-time hydration monitoring device.