This model is based on Lutchen et al. A nonlinear model combining pulmonary mechanics and gas concentration dynamics. IEEE Trans. Biomed. Eng. 29: 629-641, 1982

Description

 The model equations derived from mass and force balances describe the intrabreath 
 dynamics of pressure, flow, volume, and gas species concentration after a step change 
 in gas composition at the airway opening.

 This model has two parallel, perfectly mixed alveolar compartments connected to a single, 
 constant-volume airway (dead space) in which no mixing occurs. There is a mixing point m 
 at the junction of the two alveolar compartments and the conducting airway (see figure below). The 
 gas that enters the airway opening during inspiration will reach the mixing point after 
 the dead space is cleared. During expiration, until the dead space is cleared, the output 
 concentration at the airway opening is the input concentration. 	

Equations

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.