Theoretical Models for the Quantification of Lung Injury Using Ventilation and Perfusion Distributions. Issue 2 (2009)

• Record Type: Journal Article
• Authors: Brook, B. S.; Murphy, C. M.; Breen, D.; Miles, A. W.; Tilley, D. G.; Wilson, A. J.
• Is Part Of: Computational and mathematical methods in medicine. Volume 10:Issue 2(2009)
• Page Start: 139
• Page End: 154
• Publication Date: 2009
• Subjects: modelling -- lung disease -- [Vdot]/[Qdot] -- log normal -- tree; Medicine -- Computer simulation -- Periodicals; Medicine -- Mathematical models -- Periodicals; 610.11
• DOI: 10.1080/17486700802201592
• Languages: English
• ISSNs: 1748-670X

Abstract

Abstract : This paper describes two approaches to modelling lung disease: one based on a multi-compartment statistical model with a log normal distribution of ventilation perfusion ratio (V ˙ / Q ˙ ) values; and the other on a bifurcating tree which emulates the anatomical structure of the lung. In the statistical model, the distribution becomes bimodal, when the V ˙ / Q ˙ values of a randomly selected number of compartments are reduced by 85% to simulate lung disease. For the bifurcating tree model a difference in flow to the left and right branches coupled with a small random variation in flow ratio between generations results in a log normal distribution of flows in the terminal branches. Restricting flow through branches within the tree to simulate lung disease transforms this log normal distribution to a bi-modal one. These results are compatible with those obtained from experiments using the multiple inert gas elimination technique, where log normal distributions of V ˙ / Q ˙ ratio become bimodal in the presence of lung disease.