Mullally William, Betke Margrit, Albert Mitchell, Lutchen Kenneth
Computer Science Department, Boston University, Boston, MA, USA.
Ann Biomed Eng. 2009 Feb;37(2):286-300. doi: 10.1007/s10439-008-9603-z. Epub 2008 Dec 10.
Computational models of the human lung have been developed to study lung physiology and have been used to identify the airways responsible for mechanical dysfunction in asthmatics. Tgavalekos et al. used models anatomically consistent with the human lung to link ventilation defects to the heterogeneous closure of small airways. Their approach implicitly assumed a high degree of independence between airway closures as indicated by the low compactness of the airway structures mapped to individual ventilation defects. Venegas et al. however, have found that significant mutual dependence of airways may play a role in patchy ventilation of asthmatics. This led us to explore the question to what extent anatomically consistent models can be built which do not implicitly assume high independence of airways but instead allow for the mutual dependence of airways responsible for ventilation defects. We propose an algorithm for generating subject-specific airway-tree models that minimize the number of airways that must be closed or severely constricted to cause observed ventilation defects. We also propose novel approaches for measuring the compactness of airway structures. Our approach shows that anatomically consistent models which link compact airway structures to ventilation defects can be built. Our model also shows that some ventilation defects may be caused by closures of larger airways than previously reported.
已经开发出人类肺部的计算模型来研究肺部生理学，并用于识别导致哮喘患者机械功能障碍的气道。Tgavalekos等人使用与人类肺部解剖结构一致的模型，将通气缺陷与小气道的异质性闭合联系起来。他们的方法隐含地假设气道闭合之间具有高度独立性，这一点从映射到个体通气缺陷的气道结构的低紧密性可以看出。然而，Venegas等人发现气道之间的显著相互依赖性可能在哮喘患者的斑片状通气中起作用。这促使我们探讨一个问题：在多大程度上可以构建解剖结构一致的模型，这些模型不隐含地假设气道具有高度独立性，而是允许导致通气缺陷的气道之间存在相互依赖性。我们提出了一种算法，用于生成特定个体的气道树模型，该模型可将为导致观察到的通气缺陷而必须闭合或严重收缩的气道数量减至最少。我们还提出了测量气道结构紧密性的新方法。我们的方法表明，可以构建将紧密的气道结构与通气缺陷联系起来的解剖结构一致的模型。我们的模型还表明，一些通气缺陷可能是由比先前报道的更大的气道闭合引起的。
