Vol. 94, Issue 2, 621-630, February 2003
Chest wall kinematic determinants of diaphragm length by
optoelectronic plethysmography and ultrasonography
A.
Aliverti1,2,
G.
Ghidoli2,
R. L.
Dellacà1,2,
A.
Pedotti1,2, and
P. T.
Macklem3
1 Dipartimento di Bioingegneria, Politecnico di
Milano and 2 Centro di Bioingegneria, Fondazione Don
Gnocchi Istituto di Ricovero e Cura a Carattere Scientifico and
Politecnico di Milano, I-20133 Milan, Italy; and
3 Meakins-Christie Laboratories, Montreal Chest
Institute, McGill University Health Centre, Montreal, Quebec,
Canada H3H 2R9
To estimate diaphragm fiber
length from thoracoabdominal configuration, we measured axial motion of
the right-sided area of apposition by ultrasonography and volumes
displaced by chest wall compartments [pulmonary, abdominal rib cage,
and abdomen (Vab)] by optoelectronic plethysmography in four normal
men during quiet breathing and incremental exercise without and with
expiratory flow limitation. Points at the cephalic area of
apposition border were digitized from echo images and mapped into
three-dimensional space, and the axial distance from the xyphoidal
transverse plane (Dap) was measured simultaneously with the
volumes. Linear regression analysis between changes (
) in
Dap and the measured volume changes under all conditions
showed that 1) Dap was linearly related more
to Vab than to changes in pulmonary and abdominal rib cage volumes;
and 2) this was highly repeatable between measures. Multiple stepwise regression analysis showed that Vab accounted for
89-96% of the variability of Dap, whereas the rib
cage compartments added <1%. We conclude that, under conditions of
quiet breathing and exercise, with and without expiratory flow
limitation, instantaneous Dap can be estimated from
Vab.
chest wall volume; diaphragm area of apposition; echography
