# RFID Technology for Management and Tracking: e-Health Applications
## 3 Application Example  
### Description of the Scenario  
In order to illustrate how the RFID system proposed in this contribution works, a simple demonstration has been conducted in the Central Hospital of Asturias (\"Hospital Universitario Central de Asturias\", HUCA, Asturias, Spain). The RFID system has been deployed in rooms 312 and 314, as well as in part of the hallway of the third floor, as depicted in Figure 6. One RFID antenna has been placed on each room, providing a 3 m \(\times\) 5 m coverage in front of the antenna, which corresponds to the area of the room where the bed and the medical instrumentation are placed. Although RFID antenna models are different (see Figure 7), they have a radiation pattern very similar to the one shown in Figure 2a, which is actually the radiation pattern of the antenna depicted in Figure 3d [26], measured at the spherical range in anechoic chamber of the University of Oviedo. The coverage area has been estimated based on the methodology described in Section 2.1. Besides, the power level of the RFID reader has been adjusted to reduce the maximum reading distance up to 5 m, providing RFID tags' detection capabilities even in NLOS within the coverage area, and ensuring that RFID tags outside the reading zone will not respond to RFID reader interrogations. Figure 5: (**a**) Pseudo-code showing the interaction between an end-user and the information stored in the database. (**b**) Pseudo-code illustrating how new items are introduced in the database when the user is authenticated as administrator. Information associated to the database is highlighted in green, while end-user actions using the mobile application are denoted in red. Three RFID antennas have been connected to an Impinj Speedway Revolution 4-port RFID reader [32] that provides at least 50 readings per second (depending on the reader configuration parameters, number of antennas connected to it, etc.). The RFID reader is connected to a laptop that manages it, that is, that sets up the reader and collects the events triggered every time a RFID tag is detected, updating the database accordingly. The locations of the RFID antennas and the RFID reader are depicted in Figures 6 and 7. The database has been installed on a second laptop, aiming to have a system architecture resembling a real system, where the database would be set up in a workstation on the computer service area of the hospital. In this proof-of-concept, the database has been implemented in MongoDB (Figure 8) [33], as it is one of the most widespread SQL database softwares nowadays. An Ethernet LAN has been set up to connect the RFID reader and the two laptops. Figure 6: Scheme of the RFID system architecture used for the proof-of-concept. Figure 7: Pictures of the scenario where the RFID system has been deployed (rooms 312, 314, and hallway of the “Hospital Universitario Central de Asturias”). (**a,b**) Room 312. (**c**) Hallway and room 314. (**d**) Close-up of the placement of a RFID antenna in room 312. The end-user mobile application has been installed on two smartphones (Samsung Galaxy S3 with Android 4.3, iPhone 7 with iOS 11.4) and in a tablet (Samsung GT-P5110 with Android 4.2.2). This application has been developed in NativeScript [34] to provide support to mobile devices based on both iOS and Android platforms. The application developed for this proof-of-concept is very simple, consisting of a main window showing the list of items detected by the RFID antennas and the location (event) where they were detected (Figure 9c). If the user presses the name of an item, a second window is opened. This window provides detailed information (if available) about the tagged item, such as the ID of the RFID tag, medical information, debug information for the software developer (to be removed in a final version of the application), and the action to be done by the end-user (e.g., \"administer medicine to patient\"). Examples of this window with detailed information are shown in Figure 9a,b.