Wanderer Alarm

Automatic estimation of patient movement direction and location to prevent wandering off patients and elderly using wearable low cost passive RFID technology.

RFID has been increasingly used in automatic identification and tracking of tagged objects. More recently, the automatic determination of the spatiality of a tagged object (a tag’s position) has become a subject of growing interest with significant applications. For example in health care applications, movement direction in patient tracking applications can enable clinicians to monitor movements of patients and prevent high risk patients (such as those with dementia) from wandering off clinical areas.

A number of existing RFID localization methods for spatial identification have been applied for tracking the direction of objects tagged with active tags. Active tags employ an active transmitter with extended tag logic and therefore can generate a strong signal back to reader over a long distance. By contrast, the performance of passive RFID tags is affected by additional noise sources, which makes accurate spatial identification of a tagged object difficult in real-world situations. Sources of  noise can be as a result of the limited working range of modulated backscatter Ultra High Frequency (UHF) RFID, noise in the received signal, multi-path effects, tag incident power affect, fading and scattering.

Our research, focuses on estimating the location and direction of traversal of   passive RFID tags. 



Dr. Damith Ranasinghe

Mr. Roberto Shinmoto Torres

Mr. Asanga Wickramasinghe

Assoc. Professor Renuka Visvanathan