Measurement of Breath Frequency by Body-Worn UWB Radars: A Comparison Among Different Signal Processing Techniques

In this paper, different signal processing techniques are used to evaluate the breath frequency of volunteers starting from signals measured by a body-worn ultra-wideband radar. The measurement setup is based on a time domain reflectometry technique, and comprises an ultra-wideband antenna in contact with the subject's thorax, and a vector network analyzer. The breath frequencies, obtained applying the different processing techniques on the signal reflected from the human thorax, are compared in terms of accuracy against measures acquired by a piezoelectric belt, which is a widely adopted commercial system for respiratory activity monitoring. Finally, the different techniques are compared with each other in terms of accuracy and execution time.