Computerized measurement of pulmonary gas exchange during exercise : validation of a new approach

This study was designed to e-valuate the effectiveness of the Gould 9000 IV Computerized Exercise System for the measurement of pulmonary gas exchange during exercise. The two objectives were to quantify the error variance for continuous measurement of the mixed expired gases and determine the concurrent validity of the spirometer as a mixing chamber apparatus and reservoir with an accepted criterion, the Douglas bag technique. The experimental procedures were divided into two parts. First, four Gould 9000 IV systems were attached to the Gould Ideal Lung (GIL) exercise simulator at three intensities for five minutes. The system measured volume, FE02, FEC02, and temperature and calculated oxygen consumption (V02), carbon dioxide production (VC02), and the respiratory exchange ratio (R) every twenty seconds. Experiment two utilized 45 subjects exercising at two submaximal workloads on either a bicycle ergometer or treadmill. Simultaneous collection of expired gas was performed using the 9000 IV and Douglas bag technique to examine gas exchange parameters. [...]