Measurement of exercise ventilation by a portable respiratory inductive plethysmograph

The purpose of this study was to evaluate the accuracy of a respiratory inductive plethysmograph (RIP) designed for ambulatory data collection during exercise by comparison to a pneumotachograph. Healthy young males (n = 10) wore an elastic body garment embedded with inductance sensors encircling the rib cage and abdomen. Breathing frequency (fR), tidal volume (VT) and minute ventilation (V˙I) were monitored during 5 min of rest, slow walking (3.7 km h−1), fast walking (6.1 km h−1) and slow running (8.9 km h−1) followed by an incremental treadmill test to exhaustion (14.4 ± 2.7 km h−1). Mean fR, VT and V˙I values were not statistically different between the two methods (P > 0.05). Within each of the subjects at rest and different exercise intensities, the average coefficient of determination was high for fR, VT and V˙I (R2 = 0.9233, 0.8743 and 0.9652, respectively) and the mean bias values were low (−0.102 ± 2.91, 0.033 ± 0.207 and −0.715 ± 8.362, respectively). These data suggest that the ambulatory RIP provides reasonable estimates of ventilation during rest and exercise.