Real Time Health Monitoring System

This paper presents the design and implementation of a low-power wearable health monitoring system based on the Nordic nRF52840. The system integrates a 6-axis Inertial Measurement Unit (3-axis accelerometer and 3-axis gyroscope) for step detection and motion tracking, along with the MAX30100 optical sensor for heart rate and SpO₂ monitoring. The collected physiological and motion data are processed using embedded algorithms to estimate calorie intake and calorie expenditure in real time. The device uses Bluetooth Low Energy (BLE) for wireless transmission to a mobile system for visualization and long-term analytics. Experimental results demonstrate improved accuracy in step counting and calorie burn estimation compared to single-sensor approaches. The proposed system offers a compact, energy-efficient, and cost-effective solution for continuous health monitoring and fitness tracking.