Exposure assessment by physiologic sampling pump—prediction of minute ventilation using a portable respiratory inductive plethysmograph system
Abstract
A study was conducted to evaluate a portable respiratory inductive plethysmograph (E) for use in controlling the flow rate of a physiologic sampling pump (PSP). Specific aims were to: (1) evaluate the ability of the portable RIP system to measure
E using a direct (individual) fixed-volume calibration method (Direct
E prediction using output data from the portable RIP and subject demographic characteristics (Indirect
E estimates from indirect and direct portable RIP calibration with indirect estimation models published previously. Nine subjects (19–44 years) were divided into calibration (n = 6) and test (n = 3) datasets and performed step-tests on three different days while wearing the portable RIP and breathing through a pneumotachometer (reference). Minute ventilation and portable
E prediction that was subsequently applied to the test dataset. Direct calibration of the portable RIP system produced highly variable estimates of
E (R2 = 0.62, average % error = 15 ± 50) while Indirect
E and total volume with accuracy comparable to previously published models.