“Do I disturb?” – how your breath interferes with your wireless BAN system

Perhaps  Christian Andreas Doppler would not have imagined that his first verified experiment of 1845 would have relevance in the twenty-first century in relation to the human body.

This time instead of a wagon full of musicians, which approached and receded, the effect that has been studied is that caused by human breath. In a nutshell, the question posed is: “How do inflation and deflation of breath affect temporal fading at a specific distance?”

Luca Petrillo, Theodoros MavridisPhilippe De Doncker from the Université Libre de Bruxelles and Julien Sarrazin, Aziz Benlarbi-Delaï from Sorbonne Universités, UPMC Univ Paris 06 have studied temporal fading and the Doppler effect due to breathing at 60 GHz on the front side of an experimental human torso.

The group of researchers started their experimentation by putting a person in an anechoic chamber in order to avoid the reflections from walls, roof, floor and furniture’, and through VNA (Vector Network Analyzer) technology have performed several measurements with horizontal and vertical polarizations for different distances of detectors on the chest and on abdomen.

Apparently, the shadowing of human torso curvature affects horizontal polarized links more than vertical ones as the academics affirmed. “Experimental results reveal that horizontal links are more subject to fading than vertical links because of the shadowing of the human torso’s curvature, which overcome polarization influence.” – the researchers highlight.

The study can be considered the first step towards innovation that lie ahead in this area of ​​research as the five researchers confirm: “Future works are needed to investigate the effect of body motion (walking, running, etc.) on the fading of on-body channels on the front side of the torso at 60 GHz.”

Interested in the full research? See here the full version.