Heart rate extraction based on eigenvalues using UWB impulse radar remote sensing

Ultra wideband impulse (UWB) radar for vital signs measurement applications is getting much attention because it is a contactiess method. However, the heartbeat signal is usually be perturbed in strong noisy signals from stationary and non-stationary objects. In addition, the respiration signal, which has a much higher intensity than the heartbeat signal, makes it challenging to extract the heartbeat signal. Thus, this paper proposes an extraction method of heartbeat signal and frequency using eigenvalues. Eigenvalues of the vital signal were found to be strongly correlated with the fundamental and harmonic frequencies of respiration and heartbeat. Experimental results show that the proposed method could improve the signal-to-noise ratio of over 18 dB for different distances from 0.5 m to 3.0 m and different orientations of the person. Furthermore, the original signal of respiration and heartbeat can be reconstructed by the selection of the eigenvalues and the eigenvectors. (C) 2019 Elsevier B.V. All rights reserved.