Reliability Improvement for an RFID-based Psychiatric Patient Tracking System

The cooperation between Field Generators, Readers and Tags accomplishes the required functions in using RFID in psychiatric patient tracking. The Field Generator constantly transmits trigger signals within its transmission range. When a tag, the patient wears, receives the trigger signal from a Field Generator, it responds to a Reader with the ID of the Field Generator. Based on the Field Generator IDs that a tag responds, the location of the patient associated with the tag can be approximately estimated. However, in recent RFID based tracking systems, some phenomena will influence the reliability of signal transmission and reduce the feasibility of the tracking system. In this paper, we have experimented on an RFID-based psychiatric patient tracking system and discussed the conditions that could influence the tracking reliability. Based on the results, an algorithm is also proposed to solve the interference resulting from signal collisions between neighboring Field Generators. Experimental results show that this algorithm has significantly improved the reliability of the tracking system, and increased the feasibility of RFID for psychiatric patient tracking.