Measurement of total respiratory impedance in dogs by the forced oscillation technique.

The resistance (Rrs) and reactance (Xrs) of the total respiratory system were determined at various frequencies in 14 healthy conscious beagle dogs. A pseudorandom noise pressure wave was produced at the nostrils of the animals by means of a loudspeaker adapted to the nose by a tightly fitting mask. A Fourier analysis of the pressure and flow signals yielded mean Rrs and Xrs, over 16 s, at frequencies from 2 to 26 Hz.

Impedance measurement during air and helium-oxygen breathing before and after salbutamol in COPD patients.

1. The forced oscillation technique is an effort-independent method used to characterize the mechanical impedance of the respiratory system. To support the hypothesis that non-invasive partitioning of total pulmonary resistance is possible by this technique, impedance was measured during air breathing and after equilibration with a mixture of 80% helium (He) and 20% oxygen (O2) in 21 chronic obstructive pulmonary disease (COPD) patients by means of a forced pseudo-random noise pressure signal over a frequency spectrum from 4 to 52 Hz.

Measurement of total respiratory impedance in infants by the forced oscillation technique.

The forced oscillation technique according to Làndsér et al. (J. Appl.

Assessment of respiratory diseases and therapeutic intervention by the forced oscillation technique in feedlot cattle.

The forced oscillation technique was used to study pulmonary function in bulls during naturally acquired pulmonary-gastrointestinal disease complex known as shipping fever and as it was treated with two different antibiotics. Fifteen double-muscled bulls of the Belgian White and Blue breed were investigated. Clinical, serological and pulmonary function values were recorded during and after naturally occurring respiratory disease.

Density dependence of respiratory input impedance in normal subjects.

1. The forced oscillation technique is a non-invasive and effort-independent test used to characterize the mechanical impedance of the respiratory system. Total respiratory impedance was assessed from 4 to 52 Hz in 15 normal subjects breathing air and a helium-oxygen mixture.