# RFID Technology for Management and Tracking: e-Health Applications
## 3 Application Example
### Description of the Scenario
For the sake of simplicity, the mobile devices have been connected to the laptop hosting the database using a WLAN created ad hoc for the tests. However, the WLAN network available at the hospital could have been used to provide wireless interconnectivity. Five items (four are shown in Figure 10) were tagged with UHF RFID DogBone tags [31] in order to test the RFID system. These items were distributed between rooms 312 and 314, placing two of them on a cart used by nurses and doctors to transport medicines and medical items. The maximum number of RFID tags in these tests was not greater than 10, and the system was capable of processing 5 reads per second (taking into account the time required by all the elements of the system: RFID reader, database, and laptop acting as an interface between the database and the RFID reader). Thus, the variable _MAXCOUNT_ was set to 30, decreasing the value of the field _timeCount_ every 10 ms (_REFRESH_TIME_ = 10 ms). That means that every time a RFID tag is read it is considered active for at least 3 s (if it is read before this timeout, then the field _timeCount_ will be set back to 30, starting a new period of 3 s). First, the capability of the system to detect the tagged items was tested. For this purpose, one item was left within the coverage area of the RFID antenna located in room 312, another one was left in room 314 within the coverage area of the antenna placed in that room, and the remaining items were left outside the coverage areas. As expected, only those two aforementioned items were detected, being shown in the mobile application installed on the tablet and in the smartphone. Next, an item in room 312 was moved out of the coverage area. As expected, after 3 s since the last read, the field _timeCount_ associated to this item reached a value of 0, and in consequence, the item  
Figure 8: Screenshot of the MongoDB software [33], showing a list of the items registered in the database, together with their attributes. was removed from the list of active items. Once the item was placed again within the coverage area it was shown in the list of active items, with the same associated event \"detected in room 312\". In the third test, two items were mounted on the cart, which was placed within the coverage area of room 312. As a result, the mobile application showed 4 detected items, 3 of them in room 312. Then, the cart was moved from room 312 to room 314 at a slow pace. As soon as the cart was within the coverage area of the antenna placed in the hallway, the event associated to the items in the cart was updated to \"detected on hallway\", as shown in Figure 9c. When the cart was within the range of the antenna placed in room 314, the event associated to these two items was again updated, as shown in the following video (which also includes an overview of the system presented in this contribution): [[https://youtu.be/cvR7](https://youtu.be/cvR7) DIN-iUg]([https://youtu.be/cvR7](https://youtu.be/cvR7) DIN-iUg) (Supplementary Materials). Additional tests were conducted proving the capability of the system to detect the tagged items and to update the events accordingly. No undesired readings due to the presence of multipath were reported during these tests. Figure 9: Screenshots of the mobile application implemented to show real-time information of the tagged assets detected by the RFID system. (**a,b**) Mobile application installed in a smartphone, showing detailed information about the item detected. (**c**) Mobile application installed in a tablet, showing the list of detected items and where they are.