Pressure-Volume Loops

Pressure-Volume (PV) loops capture the quasi-static mechanical properties of the respiratory system. The Salazar-Knowles equation can be fit to the PV loops, and quasi-static elastance and compliance values can be calculated.

Abbr.	Parameter	Description
A	Salazar-Knowles Parameter	The parameter A of the Salazar-Knowles equation is an upper bounds estimate of the difference between total lung capacity and zero volume.
B	Salazar-Knowles Parameter	The parameter B of the Salazar-Knowles equation is an upper bounds estimate of the difference between total lung capacity and the predicted volume at zero pressure.
K	Salazar-Knowles Parameter	The parameter K of the Salazar-Knowles equation reflects the curvature of the upper portion of the deflation PV curve.
Cst	Quasi-static Compliance	Quasi-static compliance reflects the static elastic recoil pressure of the lungs at a given lung volume.
Est	Quasi-static Elastance	Quasi-static elastance reflects the static elastic recoil pressure of the lungs at a given lung volume.
COD	Coefficient of Determination	The COD is a quality control parameter measuring the goodness of the model fit.
Area	Area of PV Loop	The area enclosed by the pressure volume loop provides an estimate of the amount of atelectasis (airspace closure) that existed before the PV loop manoeuvre.