A Microcontroller-Based Embedded System for Accurate Real-Time Cardiac Output Estimation Using Impedance Cardiography with IoT-Enabled Remote Monitoring

Accurate and continuous monitoring of cardiac output (CO) is critical for early detection of cardiovascular dysfunction. This paper presents a fully functional microcontroller-based embedded platform for non-invasive estimation of CO using Impedance Cardiography (ICG). The system integrates a bioimpedance sensing front-end based on the AD5933 impedance analyzer, real-time signal processing modules, hemodynamic parameter extraction, and Bluetooth/IoT connectivity for remote monitoring. To ensure robust performance under variable measurement conditions, the design incorporates low-latency artifact suppression through sensor fusion (accelerometer and gyroscope) and adaptive thresholding. A multistage signal processing pipeline featuring VMD-NLM-DWT filtering enhances ICG waveform fidelity for precise extraction of fiducial points. CO is estimated using a modified Kubicek model with subject-specific calibration. The platform achieves sub-5 ms response time, average power consumption below 2 mW, and a mean absolute error (MAE) of 0.32 L/min when compared to Doppler echocardiography across 20 subjects. The proposed platform offers a compelling solution for low-cost, scalable, and clinically relevant real-time cardiovascular monitoring in both clinical and remote diagnostic environments.