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.
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.
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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)
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.