Vital signs monitoring using impulse based UWB signal

UWB technology is a new, useful and safe technology in the field of wireless body networks. This paper focuses on the feasibility of estimating vital signs-specifically breathing rate and heartbeat frequency-from the spectrum of recorded waveforms, using impulse-radio (IR) UWB radar. To this end, an analytical model is developed to perform and interpret the spectral analysis in each case. Both the harmonics and the intermodulation between respiration and heart signals are addressed. Simulations have been performed to demonstrate how they affect the detection of vital signs and also to analyze the influence of the pulse waveform in the case of UWB sensors. A filter to cancel out breathing harmonics is also proposed to improve heart rate detection. The motion of the antennas (for instance in hand-held devices) or of the person combines with the signal and might obscure physiological motion. In this work, a technique for movement compensation will be presented.