On Architecture of Self-Sustainable Wearable Sensor Node for IoT Healthcare Applications

In healthcare applications, the remote monitoring of moving patients depends on wearable nodes that should be mobile. Thus, wearable nodes should be power mains-disconnected most of the time to enable natural wandering of patients in the area. Thus, easy-to-use models are utilized in a seamless way. From this perspective, it becomes necessary to develop a generation of wearable nodes that are energy self-sustainable with minimal dependency on fixed power sources and also more safe in light of world health organization recommendations. In this paper, a solar energy harvesting technique is proposed to provide a mains power supply for an independent continuous operation of a patient monitoring node in sunny environments. A case study is built experimentally whereas the proposed designed node is architected as a combined node that enables parallel measurements of heart rate, blood oxygen saturation (SpO2), and body temperature. The experimental results show that the wearable node can survive more than 28 h without battery recharging from the mains. While the charging time of the battery from the solar energy harvesting is approximately 2 h.