Low cost and batteryless sensor-enabled radio frequency identification tag based approaches to identify patient bed entry and exit posture transitions

- We investigate a batteryless sensor enabled RFID tag for falls prevention near beds.
- We study two algorithms for automatic detection of bed entry and exits in real-time.
- The sensor on the sternum method performed better than the sensor on mattress.
- A study showed sensitivity to be 90.4% for bed exit using the sensor on sternum.
- A study showed specificity to be 93.80% for bed exit using the sensor on sternum.

IntroductionFalls in hospitals and residential care facilities commonly occur near the bed. The aim of this study was to investigate the accuracy of a continuously wearable, batteryless, low power and low cost monitoring device (Wearable Wireless Identification and Sensing Platform) with a single kinematic sensor capable of real-time monitoring to automatically detect bed entry and exit events.Materials and methodsThree dimensional acceleration readings and the strength of the transmitted signal from the WISP was interpreted to identify bed exit events and sensitivity, specificity and Receiving Operator Curves (ROC) were determined.ResultsThe sensor located over sternum method performed best with sensitivity and specificity values of 92.8% and 97.5% respectively for detecting bed entry and values of 90.4% and 93.80% respectively for bed exit. On the other hand, the sensor-on-mattress algorithm achieved sensitivity and specificity values of 84.2% and 97.4% respectively for bed entry and 79% and 97.4% for bed exit detection.ConclusionThe WISP located over the sternum method is the preferred method to detect bed entry and exit. However, further work in frail older people is required to confirm the performance of this method.