A ZigBee Based Multi-hop Health Monitoring System: Design and Performance Evaluation

With the increasing in the aging population, the health of the elderly caused widespread concern. The recently developed body sensor networks (BSN) have been confirmed to be a low cost and efficient way for elderly health monitoring. In this paper, we mainly introduced the design of a heterogeneous ZigBee based multi-hop health monitoring system which consisted data Collecting Node (CN), data Relaying Nodes (RNs), and Health Monitoring Nodes (HMNs). The CN and the RNs have prefixed position and they composed the main traffic routes for data transmission. The HMNs are placed on human body to sample the physiological signals of the people while the people can move freely in the floor of the building. In addition, the CN and the RNs have comparatively high radio transmission power to guarantee the network connectivity and coverage while the HMNs are always working with low radio transmission power to reduce energy consumption and to extend the life of the nodes. In addition, the designed health monitoring system were tested in the 11st floor of our laboratory (Area: 26.4m 52.8m), and the experiments results show that the network throughput is as high as 70.56 kbytes/s, the bit error ratio (BER) is lower than 0.03% and the packet loss ratio (PLR) is lower than 0.4%.