Journal of Applied Physiology, Vol 39, Issue 2 305-311, Copyright © 1975 by American Physiological Society
A modified measurement of respiratory resistance by forced oscillation during normal breathing
D. C. Stanescu, R. Fesler, C. Veriter, A. Fans and L. Brasseur
We have modified the measurements of the resistance of the respiratory
system, Rrs, by the forced oscillation technique and we have developed
equipment to automatically compute Rrs. Flow rate and mouth pressure are
treated by selective averaging filters that remove the interference of the
subject's respiratory flow on the imposed oscillations. The filtered mean
Rrs represents a weighted ensemble average computer over both inspiration
and expiration. This method avoids aberrant Rrs values, decreases the
variability, and yields an unbiased mean Rrs. Rrs may be measured during
slow or rapid spontaneous breathing, in normals and in obstructive
patients, over a range of 3-9 Hz. A good reproducibility of Rrs at several
days' interval was demonstrated. Frequency dependence of Rrs was found in
patients with obstructive lung disease but not in healthy nonsmokers.
