Recording proximity to everyday objects with a radio frequency identification logger while performing activities of daily living

In this contribution we present a portable system which records interactions with objects of daily use automatically. The system is based on an Ultra High Frequency (UHF) Radio-Frequency IDentification (RFID) device and can be worn around the wrist. It is able to detect proximity to objects marked with an RFID tag, store collected information and transfer it wirelessly to a server. Such devices are developed worldwide to enable elderly people to live independently at home as long as possible. One approach, which we aim at with our concept, is to record Activities of Daily Living (ADL), thus making cognitive decline in elderlies easier to detect and compensate. Compared to other approaches (e.g. video/audio surveillance, presence sensors, floor pressure sensors), RFID-based solutions have the advantage of preserving the user´s privacy, being robust with multiple inhabitants (or pets) and being easy and low-cost to install. However, their detection range and portability tend to be lower. In this article we present the concept and its evaluation in respect to the achievable detection range and ability to detect proximity to objects in a simulated breakfast scenario.