Validation of Respiratory Inductive Plethysmography for Measuring Exercise Tidal Volumes

Abstract : This study validated the accuracy of tidal volume (VT) measurements obtained with a respiratory inductive plethysmograph (RIP) to determine its reliability for measuring ventilation during studies of exercise and respirator wear. Values from the RIP were compared with simultaneous flowmeter volumes in 8 healthy subjects at 5 incremental work rates (60, 90, 120, 1 50, and 1 80 W) of cycling and treadmill exercise. During cycling, average RIP and flowmeter values did not differ significantly at work rates below 1 80 W for 5 of the 8 subjects. Average RIP and flowmeter VT were similar at work rates below 1 50 W for 5 of the 6 subjects who completed the treadmill iteration. The variability in these results may be attributed to several factors including RIP calibration errors and slippage of the RIP elastic bands containing the inductive coils. Correlations of breath-by-breath flowmeter and RIP VT were significant for each subject during cycling and treadmill exercise. These findings suggest that the RIP can provide reliable, noninvasive measurements of ventilation during exercise with and without respirator wear.