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 (f(R)), tidal volume (V-T) and minute ventilation (<(V)over dot >(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 f(R), V-T and <(V)over dot >(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 f(R), V-T and (V) over circle (I) (R-2 = 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. (c) 2006 Elsevier B.V. All rights reserved.