Comparison of calibration methods for respiratory inductive plethysmography in infants.
In infants under the age of 6 mo respiratory inductive plethysmograph (RIP)-calculated tidal volumes (VT) were compared with simultaneously measured volumes using a pneumotachograph (PNT) to 1) assess whether using multiple points (MP) along the inspiratory profile of a breath is superior to using only VT when calculating volume-motion (VM) coefficients, 2) verify the assumption of independent contributions of the abdomen and rib cage to VT, which was accomplished by extending the normal RIP model to include a term representing interaction between these two compartments, and 3) investigate whether VM coefficients are sleep-state dependent. Neither use of multiple points nor inclusion of the interacting term improved the performance of the RIP over that observed using a simple two-compartment model with VT measurements. However, VM coefficients obtained during quiet sleep (QS) were not reliable when used during rapid-eye-movement (REM) sleep, suggesting that coefficients obtained during one sleep state may not be applicable to another state where there is a substantial change in the relative abdominal/rib cage contributions to VT.
Institute of Biomedical Engineering, University of Toronto, Ontario, Canada.
M D
MD
Revow
S J
SJ
England
H A
HA
Stogryn
D L
DL
Wilkes
D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008176:Lung Volume Measurements; D009991:Oscillometry; D010991:Plethysmography / Q000379:methods*; D012894:Sleep Stages; D013990:Tidal Volume