Title: Robustness and Capacities of the Human Respiratory System assessed by Multiscale Modeling

Abstract:
System engineered organ representations based on multiscale imaging provide insight into the evolutionary shaped design of the transport networks in terms of modularity, physical optimality and robustness. We show that the dimensions of airways in human lungs change systematically from area-preserving to area-increasing,thus they reflect
multifractal properties. Simulations performed by our LungSim program provide insight into distinct dynamical patterns of oxygen concentration over the breathing cycle and how resistance in the network of airways mediates convection dependent heterogeneities. Our model determines the resistance in all conductive bronchioles with respect to geometry and location within the network of airways. We show that resistance determined by the network topology of airways enhances a mismatch between physiologically demanded and predicted oxygen supply, which offers an explanation for the excess diffusion capacity of human lungs. A particular advantage of our approach is the ability to study the contribution of pathologies and aging on the function of the lung as a whole aimed to improve diagnostics and intervention planning. 

Note:  LungSim is freely available for download through
http://www.simtk.org/home/lungsim.