Experimental Assessment of Wireless Monitoring of Axilla Temperature by Means of Epidermal Battery-Less RFID Sensors

Wireless epidermal devices (WEDs), based on UHF radio frequency identification (RFID), enable a contactless and noninvasive human body monitoring through sampling of health parameters directly on the skin. With reference to body temperature, this letter reports an experimental campaign aimed at assessing the degree of agreement of a battery-less plaster-like WED, placed in the armpit region, with a standard axilla thermocouple thermometer. A measurement campaign over 10 volunteers, for overall 120 temperature outcomes, revealed a good correlation among the instruments (Person's coefficient
p
= 0.78) and a difference of less than 0.6 °C in the 95% of the measured cases, provided that a user-calibration is applied. RFID-WED enables a noncontacting reading up to 20 cm and direct connectivity with a cloud architecture. Envisaged applications are the periodic monitoring in clinical and domestic scenarios, as well as the screening of restricted communities related to COVID-19 control and recovery.