Flow And Volume Related AR-modelling Of Lung Sounds

Usually, the analysis of phonopneumography (PPG, lung sound recordings) is implemented as an automated form of auscultation, in which spectral features of normal breath sounds as a function of time play an important role. In this paper, a new approach to PPG analysis is proposed. Ultimately, not the lime-dependence is important as such, but rather the dependence upon the phase within the respiratory cycle. Experimental results indicate that this dependence can be quantified by relating time-varying AR-coefficients of the PPG to simultaneously recorded flow and volume signals. This may allow to identify physiclogically meaningful quantities directly from recordings.