Single compliant tank driven by pleural pressure. This is the simplest lung model possible.
This is the simplest lung model. The lung is a compliant sac with resistance to filling, i.e. a single RC tank. The model is driven by a sinusoidal function of "intrapleural" pressure. Compliance is a chord compliance such that V--> 0 if P --> 0. P, pressure represents intrapleural pressure, negative in order to keep lung volume > zero. Parameter values are approximate for a human adult.
P = PInit + PDelta*sin(2*PI*freq*t+PI/2) - PDelta
V:t = -(P + V/C) / R;
V = lung volume, P = interpleural pressure, PDelta = small change in pressure, R = lung resistance, C = lung compliance
The equations for this model may be viewed by running the JSim model applet and clicking on the Source tab at the bottom left of JSim's Run Time graphical user interface. The equations are written in JSim's Mathematical Modeling Language (MML). See the Introduction to MML and the MML Reference Manual. Additional documentation for MML can be found by using the search option at the Physiome home page.
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Y.C. Fung; Biomechanics, Springer, 1993
Please cite https://www.imagwiki.nibib.nih.gov/physiome in any publication for which this software is used and send one reprint to the address given below:
The National Simulation Resource, Director J. B. Bassingthwaighte, Department of Bioengineering, University of Washington, Seattle WA 98195-5061.
Model development and archiving support at https://www.imagwiki.nibib.nih.gov/physiome provided by the following grants: NIH U01HL122199 Analyzing the Cardiac Power Grid, 09/15/2015 - 05/31/2020, NIH/NIBIB BE08407 Software Integration, JSim and SBW 6/1/09-5/31/13; NIH/NHLBI T15 HL88516-01 Modeling for Heart, Lung and Blood: From Cell to Organ, 4/1/07-3/31/11; NSF BES-0506477 Adaptive Multi-Scale Model Simulation, 8/15/05-7/31/08; NIH/NHLBI R01 HL073598 Core 3: 3D Imaging and Computer Modeling of the Respiratory Tract, 9/1/04-8/31/09; as well as prior support from NIH/NCRR P41 RR01243 Simulation Resource in Circulatory Mass Transport and Exchange, 12/1/1980-11/30/01 and NIH/NIBIB R01 EB001973 JSim: A Simulation Analysis Platform, 3/1/02-2/28/07.