Model number

This model represents an inertial flow in a rigid airway, compliant bronchiole, compliant bronchiolus and a compliant alveolus.


 This model represents a rigid airway, compliant bronchiole, compliant bronchiolus 
 and a compliant alveolus. A single resistor (R11) represents the resitance offered by the 
 airway wall to the airflow. The compliance and the resitance of the bronchiole 
 are represented by the resistor (R21 and R22) and the capacitor (Com21). Likewise the compliance and 
 the resistance offered by the respiratory bronchiole or the bronchiolus are 
 represented by the resistor (R31 and R32) and a capacitor (Com31). The alveolar sac compliance is 
 repsented by a capcitor (Com4). The alveolar sac changes its volume as a function of inlet
 flow or pressure. The resistance offered by the alveolus is represented by R41. 

diagram 1


P12 - P21 = Finlet * R21
P21 - P22 = F22 * R22
P21 = (V21-V21_0)/Com21
P22 - P31 = F22 * R31
P31 = (V31-V31_0)/Com31
P31 - P32 = F32 * R32
P32 - P41 = F32 * R41
P41 = (V41-V41_0)/Com41
d(Finlet)/dt = (Pinlet - P12 - (Finlet * R11))/L11
d(V21)/dt = F21
d(V31)/dt = F31
d(V41)/dt = F32
F21 = Finlet - F22
F31 = F22 - F32

Where: P is pressure, F is flow of “incompressible” air, R is resistance, 
       Com is capacitance, and V is the volume. 
Download JSim model project file

Help running a JSim model.

  K. R. Lutchen and G. M. Saidel, "Estimation of mechanical parameters in multicompartment models 
  applied to normal and obstructed lungs during tidal breathing," IEEE Trans. Biomed. Eng., vol. BME-33, 
  no. 9, pp. 878-887, Sept. 1986.

  Biomechanics by Y.C. Fung (Text Book)
Key terms
Compliant alveolus
Compliant airway
Compliant bronchiole
Compliant bronchiolus
Respiratory system
respiratory mechanics

Please cite 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 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.