Rigid_bronchiole_compliant_alveolus

Mechanics of a rigid resistive bronchiole with compliant alveolar sac. The driving pressure is at entrance to the bronchiole; the reference extrathoracic pressure is constant at zero.

Model number: 0189

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Description

 This model represents a rigid bronchiole with a compliant alveolar sac. 
 The resistance offered by bronchial wall to the flow of air is represented by
 the resistor in the model. The alveolar sac compliance is repsented by a capcitor.
 This model lacks the pleural pressure because of which a pressure pulse
 is used to drive the model.The pressure pulse represents the pressure difference
 in the alveolar space and the pleural sac. The alveolar sac changes
 its volume as a function of inlet flow or pressure. For a step function in the pressure
 the volume of the alveolar sac increases as an exponential function.

Figure Legend:
Finlet: Inlet Flow, P: Pressure, R: Resistance, F: Flow, Com: Compliance, V: Volume.

Equations

Pinlet - P2 = Finlet * R1
P2 - P3 = Finlet * R2
P3 - P4 = (V1 - V1_0)/Com1
d(V1)/dt = Finlet

Where: P is pressure, F is flow, R is resistance, Com is capacitance, and V is the volume.

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References

  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.

  Levitzky MG. "Mechanics of Breathing", Pulmonary Physiology. 7th Edition, New York: McGraw-Hill, 2007, p. 11?53

Key Terms

Alveolus, Alveolar sac, lung mechanics, positive pressure ventilation, chest wall compliance, Respiratory system, respiratory mechanics, airway

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Acknowledgements

Please cite www.physiome.org 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.

[This page was last modified 03Feb10, 12:12 pm.]

Model development and archiving support at physiome.org provided by the following grants: 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.