Exploration of Mode Decomposition for Concurrent Cardiopulmonary Monitoring using Dual Radar

Cardiopulmonary monitoring involves surveilling the important physiological parameters of an individual like the breathing rate (BR) and the heart rate (HR). This paper uses a simple, off-the-shelf dual multifrequency Continuous Wave (CW) radar setup to monitor the BR and HR of a static individual. The source separation problem of extracting the HR signal in presence of a higher amplitude BR signal poses a huge challenge and has been effectively solved by using an optimal channel selection process and the Variational Mode Decomposition (VMD) algorithm in this paper. Frequency extraction from the nonstationary signal modes produced by VMD has been performed by using the Fourier-Bessel transform to extract precise frequency information. Results show that the proposed system is accurate and outperforms other existing mode decomposition methods like Empirical Mode Decomposition (EMD) and Ensemble Empirical Mode Decomposition (EEMD) with a mean absolute error of 5.1±5.4 with respect to the number of heartbeats per minute and an accuracy of 95.87%(±4.9) with respect to the number of breaths per minute.