[Measuring airway resistance with the oscillation method: Oscillaire and Custovit].

Measurement of airway resistance by the oscillation method was done on the one hand by means of the pseudo random noise method (Oszillaire, Jones Company) multifrequence from 6 to 26 Hz in steps of 2 Hz. In addition, the oscillatory resistance was also determined by means of the custo vit (Customed), the frequency of the pump producing the oscillation being variable so that measurements were carried out successively at different frequencies. 2 different versions were tested. In the first version the resonance frequency was measured and then monofrequently the pertaining resistance. In another version the impedance (total airway resistance) was measured at different frequencies in a frequency range between 6 and 20 Hz in steps of 2 Hz with both methods. Additionally, the airway resistance was also measured by bodyplethysmography. A clinical study was carried out in a group of 21 healthy subjects and 34 obstructed patients with asthma bronchiale and chronic obstructive lung disease. When measuring the airway resistance with the custo vit at the frequency of resonance there was poorer differentiation between normal and obstructed subjects compared to a measurement at a fixed frequencies yielded comparable values for both methods.