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Periodic airway transport and alveolus-capillary gas exchange.

Model number: 0156

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 A homogeneous model for respiratory gas exchange is presented. It contains an alveolar sac (compartment) 
 connected to a 1D airway (cylinder). The alveolar sac exchanges species with a capillary 
 (cylinder) through a single layer. The model can predict time dependent airway concentration 
 profiles in the presence of bidirectional air flow over a single or multiple breath time 
 span. Source of species can be set either in air or in blood. 	


where is the species concentration, is the volume, is the volume flow rate, is the diffusion coefficient, is the length, is the pereability-surface product, is the reaction rate, is the specie flux per unit length of capillary-alveoli interface, is the integrated specie flux through capillary-alveoli interface, is the Heaviside function, index refers to the capillary, index refers to the capillary-alveoli interface, index refers to the alveolus, and index refers to the airway.

The equations for this model may also 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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 Hlastala MP, A Model of Fluctuating Alveolar Gas Exchange During the Respiratory Cycle. 
 Respir. Physiol. 15: 214-232, 1972 	

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Key Terms

gas exchange, alveolar exchange, pulmonary circulation, bronchial circulation, pulmonary capillaries, airway, alveolar sac, PDE

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Posted by: bej


Please cite in any publication for which this software is used and send an email with the citation and, if possible, a PDF file of the paper to:
Or send a copy to:
The National Simulation Resource, Director J. B. Bassingthwaighte, Department of Bioengineering, University of Washington, Seattle WA 98195-5061.

[This page was last modified 14Mar18, 3:17 pm.]

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.