Section: New Results

Lung and respiration modeling

Participants : Laurent Boudin, Muriel Boulakia, Céline Grandmont, Jessica Oakes, Nicolas Pozin, Irène Vignon-Clementel.

In silico models of flow and transport in the lung are increasingly being used to predict regional deposition in healthy and diseased lungs. However, very few models have been validated with in vivo human or animal experimental data. In [36] , we create a physiologically-based simulation of airflow and particle transport in healthy and emphysematous rat lungs. Excellent agreement between the numerical predictions and experimental data is found for the healthy lungs. However, the numerical predictions are unable to predict the experimental findings of enhanced deposition in the normal regions of the emphysematous lungs and thus more sophisticated models of transport in the deep regions of the lung are needed. This is what is being explored in [42] , where interactions of flow and transport between 3D upper-parts and 1D downstream respiratory trees are captured for inspiration and expiration for the first time.

While several groups have investigated detailed flow and particle transport in the acinar regions of the healthy lung, little is currently known about diseased acini. In [35] we perform numerical simulations of flow and transport in healthy and emphysematous acini. As the alveolar septa is deteriorated in emphysema there is less surface area available for particles to deposit on. Therefore, fewer particles deposit in the diseased models. In addition, we find that particle deposition is more heterogeneously distributed in emphysema, a phenomenon that was also found in the in vivo animal experiments.