Estimation of Breathing Frequency and Heart Rate by Biometric UWB Radar

Ultra-wideband (UWB) radars which are mainly focused on contactless detection of breath, heartbeat and other biological signals are generally referred to as biometric radars. It is expecting that these radars will find a whole range of applications from the medical field, through supporting emergency situation solution, up to monitoring people in their dwelling (e.g. ambient assisted living programs). Motivated by promising applications of biometric radars, we will focus in this paper on contactless measurement of breathing frequency and heart rate of static persons by UWB radar. At first, the algorithm for the estimation of the breathing frequency of a person will be outlined. Then, the main emphasis will be placed on the development of an efficient approach for the heart rate estimation. The proposed solution will include radar signal processing procedure for static person ranging, methods for improvement of low-level echo of target-to-clutter and noise ratio (exponential averaging, low-pass filter, Savitzky-Golay filter and single delay line canceller), and finally the heart rate estimation itself (peak-to-average power ratio, Welch periodogram). The good performance of the proposed algorithms will be illustrated by experimental results.