Exact measurements of nasal resistance with the oscillation method.

It is demonstrated how it is possible to obtain a certain determination of the nasal resistance with the oscillation method respecting the whole airway resistance while measuring the flow. The 68 measurements with 17 probands under varying situations indicate that the values obtained are exactly the same with the two methods. There are only a few values which are outside the confidence limits. These are caused by interference from the regulation mechanism of the airway resistances e.g. in the nasal pharynx, larynx and bronchioli by augmentation of functional residual volume, which cannot be avoided. The averages of the two measurements are identical. There is no systematic error.