# Electromagnetic Assessment of UHF-RFID Devices in Healthcare Environment
## 2 Materials and Methods
### UHF-RFID Devices Assessed  
At the beginning of the process, there is an in situ analysis performed to identify the source of RF emission within the surrounding area. The in situ RF exposure assessment was performed at the measurement area, with the use of the selected exposure metric, measurement type and measurement techniques to satisfy the measurement objectives. Figure 2 depicts specific devices that were included into the study, i.e., manually operated (MO) and autonomous gate (AG) and autonomous shelf (AS) RFID readers (as specified in Table 1, including passive tags compatible with all the specified readers). \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Description**} & \multicolumn{2}{c}{**Key Parameters of the RFID UHF Readers Used for the Study**} \\ \cline{2-4}  & **Handheld Reader** & **Fixed xArray** & **Shelving DYANE** \\  & **AB700** & **Gateway R680** & **Smartshelf** \\ \hline \multirow{2}{*}{Reader type} & Manually Operated & Autonomous Gate & Autonomous Shelf \\  & (MO-RFID reader) & (AG-RFID reader) & (AS-RFID reader) \\ \hline \multirow{2}{*}{Frequency} & 860–960 MHz & 860–960 MHz & 860–960 MHz \\ \hline \multirow{2}{*}{Air Interface Protocol (compliant tags)} & EPCglobal UHF RFID & EPCglobal UHF RFID & EPCglobal UHF RFID \\  & Class 1 Gen 21 & Class 1 Gen 2 & Class 1 Gen2 \\  & ISO/IEC 18000-63 & ISO/IEC 18000-63 & ISO/IEC 18000-63 \\ \hline \multirow{2}{*}{Max Receive  Sensitivity} & \multirow{2}{*}{not available} & \(-\)82 dBm & \(-\)84 dBm \\  & & [0.5 mV/m] & [0.4 mV/m] \\ \hline \multirow{2}{*}{Tag read sensitivity} & \multicolumn{2}{c}{from (\(-\)22 dBm) to(\(-\)10 dBm)} \\  & & [equivalent to the range: 0.5–2 V/m] \\ \hline \multirow{2}{*}{Reading  Range} & 0–7 m & up to 1.5 m & \multirow{2}{*}{ \begin{tabular}{c} the entire interior \\ of the cabinet \\ \end{tabular}  } \\  & (according to tag & (according to tag & (according to tag & \\  & and environment) & & of the cabinet \\ \hline \multirow{2}{*}{Writing  Range} & 0–3 m & \multirow{2}{*}{not applicable} & \multirow{2}{*}{not applicable} \\  & (according to tag & & \\  & and environment) & & \\ \hline \multirow{2}{*}{Transmitted  Power} & \multirow{2}{*}{up to 1 W ERP} & up to 2 W ERP (EU1) & \multirow{2}{*}{up to 1 W ERP (EU1)} \\  & & 4 W ERP (FCC) [28] & & \\ \hline \multirow{6}{*}{Antenna} & \multirow{6}{*}{1 antenna} & \multirow{6}{*}{1 phase array antenna (52 dual-polarized beams in 9 sectors)} & \multirow{2}{*}{4 expandable to 32 antennas with  Speedway Antenna} \\  & & (52 dual-polarized & \\ \cline{1-1}  & & beams in 9 sectors) & \\ \cline{1-1} \cline{3-4} \cline{The handheld readers (AB700 (ETSI)) are gun-shaped transceivers, normally used close to the human body. The RFID is used as shown in Figure 2a and can affect specific parts of the operator's body. It is recommended to make RFID readings with the arm extended to limit the exposure, but it increases the musculoskeletal load experienced by operator [7; 8; 30]. The relevant technical specifications are specified in Table 1.  
The UHF-RFID fixed xArray (Gateway R680 (ETSI)) used for the study is located within at the Hospital Universitario de Canarias (HUC). The platform was installed for the assessment purpose, and the compliance with the requirements set was conducted. The xArray provides real-time identification and localization of the tagged items. It was positioned in the center of a room ceiling, with a room height of approximately 3.5 m, and eventually the housed estimated area was of 8 \(\times\) 8 m. The Impinj's Item Sense management software triggers and automatically handles the management and monitoring infrastructure. The UHF-RFID device used for the study is presented in Figure 2b and the relevant technical specifications are presented in Table 1.  
The device DYANE Smartshelf subject to assessment hereunder is an RFID smart shelving system, that is used for automation of tagged reagent inventory control in operating theatres and clinical laboratories in real time. It is presented in Figure 2c.