Microwave Wearable System for Sensing Skin Hydration

In spite of the technological advancement of the healthcare system, monitoring skin hydration still remains a challenging task. The solutions currently available in the literature are inadequate to obtain continuous real-monitoring, especially in a wearable perspective. Starting from these considerations, this paper addresses the implementation of an innovative wearable device that can monitor skin hydration through microwave reflectometry technique. In particular, a preliminary validation was carried out through time-domain reflectometry (TDR) in-vivo measurements, from which the corresponding frequency-domain (FD) data were extrapolated. Successively, an in-depth study on the frequency response of the sensing element designed with respect to different skin hydration levels was carried out through full-wave simulations on human phantoms. This strategy allowed to consider different reference skin hydration levels and to obtain specific calibration curves relating the dielectric permittivity of skin to the FD-response of the monitoring system. The obtained results have thus led to the implementation of a system based on microwave reflectometry, with large potential for real-time, continuous monitoring of skin hydration.

Automated summary

This paper discusses the implementation of an innovative wearable device for monitoring skin hydration through microwave reflectometry technique. The study involved experimental validation and full-wave simulations on human phantoms to establish the relationship between skin dielectric permittivity and the monitoring system's frequency response. The results suggest that the system has the potential for real-time, continuous monitoring of skin hydration.