Fig. 5
From: An objective method to detect sighs during cardio-pulmonary exercise testing
Example of a regular breathing (A) and of two sighs (B). High resolution (125 Hz) flow-over-time (red) data and volume-over-time (blue) data. Spikes of tidal volume are detected on the unfiltered cycle-by-cycle raw data of Geratherm® using unfiltered cycle-by-cycle data compared to centered value of the rolling median of 15 points. Cross-correlation of Geratherm® unfiltered cycle-by-cycle data with the high-resolution data allowed the analysis of each spike of tidal volume detected, which are illustrated by a black vertical line delimitating the start of the spike of VT. In figure B, Individual readings of the two spikes of VT by two independent scorers confirmed two deep inspirations representing sighs and not another phenomenon.
