A self-powered wearable device using the photovoltaic effect for human health monitoring

Wearable monitors have revolutionized the healthcare industry with help of non-invasive measurement technologies. However, the adoption of these vital monitors faces challenges such as high-power consumption and limited battery lifetime. In this paper, to overcome these challenges, a self-powered wearable monitoring system is designed, integrated, and experimentally validated. The system includes a photovoltaic panel (PV), a DCDC converter, supercapacitors, a pulse sensor, an accelerometer, a microcontroller unit and a Bluetooth module to extract critical physiological parameters, including heart rate, oxygen saturation, activity of daily living and deliver wireless data access to a mobile device. A theoretical model of the energy balance model was established to realize the balance between the energy harvesting capability and sensing power consumption. In an experimental study, a 50 F supercapacitor stored 430 J in 4 hours (29.9 mW) using a PV energy harvester at 500 W/m², which allows the sensor system (power consumption 5mW) to run sustainably for 24 h.