Evaluation of Wireless Body Area Sensor Placement for Mobility Support in Healthcare Monitoring Systems

We present a 2-tier wireless system for healthcare monitoring of convalescing patients in non-critical condition. A network of sensors adhered to the patient’s body used for vital signs collection, and a portable coordinator device forms one tier, whereas a point-to-point link between the coordinator and a fixed access point forms the other tier. We implemented a simple but effective handoff protocol to support uninterrupted monitoring of mobile patients by employing sensor devices featuring limited radio range and low power usage that are amenable for home use. Our experiments reveal that the wrist location is the most favoured for data relaying at walking speeds, as compared to the shoulder, hip, and ankle locations. Additionally, we observed that using sensor nodes as temporary relays may reduce the packet loss rate down to 20% of the value measured when employing a single hop delivery scheme between the coordinator and the access points.