Figure 1.

Supine tidal flow-volume curves (control and during NEP of -5 cmH₂O) and corresponding expiratory flow-time curves (only during NEP) in representative subjects of the different groups. The hatched areas under the flow measure the volume exhaled in the first 0.5 sec. (V,NEP_0.5) and 1 sec. (V,NEP₁) after NEP application.