Single compliant tank driven by pleural pressure. This is the simplest lung model possible.

Description

 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.

Equations

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.