Automatic identification and placement verification of wearable wireless sensor nodes using atmospheric air pressure distribution

We present a new approach to identifying and verifying the location of wearable wireless sensor nodes (W²SNs) placed on a body by inferring differences in altitudes using atmospheric air pressure sensors. This technique is aimed at long-term, in-home monitoring applications of the elderly and patients with chronic conditions, where the user has the freedom to install and remove the W²SNs as required without caregiver assistance. Our prototype shows that each IEEE 802.15.4-capable W²SN, employing pressure sensors, is capable of detecting altitude changes sufficient to distinguish between the relative elevation of a patient´s arm and leg, and recognize which W²SN is placed on which limb; preliminary results show detection in altitudes down to 39cm apart.