MONOFREQUENCY FORCED OSCILLATION TECHNIQUE FOR THE INVESTIGATION OF PULMONARY-FUNCTION IN CALVES - IN-VITRO AND IN-VIVO STUDIES

Parameters derived from the non-invasive and simple monofrequency forc ed oscillation technique mere compared with classical parameters of ve ntilatory mechanics in order to assess its usefulness for the investig ation of pulmonary function in calves. To facilitate this comparison, theoretical derivations were coupled with in vitro measurements, using an artificial lung model, and with in vivo studies. These studies com pared the oscillatory resistance parameters (R(OS) and Re) and the res piratory system compliance (C-rs) against the classical pulmonary resi stance (R(L)) and the dynamic compliance (C-dyn), respectively. R(OS) and Re were highly correlated (r greater than or equal to 0.87) with R (L) and the comparison between C-rs and C-dyn gave a similarly high co rrelation (r greater than or equal to 0.88). Given its simplicity, its correspondence with classical parameters and its rapidity and reprodu cibility, monofrequency forced oscillation technique seems well suited for the investigation of pulmonary function under field conditions.