Figure 3.

Minute ventilations during all experiments. The ordinate displays minute ventilation (V·e) in L/min and the abscissa displays Naughton work stages. The insert indicates the studies performed with room air (RA), O₂ at flows of 2 L/min (2LO₂), and devices 1 through 4 (D1–D4). The data points are mean values and the brackets indicate 1 SEM. The zero values represent resting observations. A, B, and C depict the experiments performed at regulator settings of 2, 5, and continuous, respectively.