Noninvasive Microwave Sensor for Real-Time Continuous Dehydration Monitoring

Accurately assessing dehydration is crucial in many diverse clinical applications and the sports industry. Currently used methods for assessing dehydration rely on either skin pinch tests or analysis of urine. Therefore, there is a need for wearable noninvasive devices for continuous dehydration monitoring. This article presents a novel sensor design for the monitoring of dehydration levels by the use of chipless microwave resonators. The sensor design incorporates a metallic layer beyond the tag sensor itself, resulting in an isolation of the dehydration sensing system from conflicting ambient signals that provide a targeted sensing system to the tissue itself with reduced interference. The sensitivity of the sensor is high, with a ~120 kHz shift for a 1% change in dehydration) at the resonance frequency between 0.9–1 GHz.