Pulmonary hypertension: fluid dynamics modeling in networks

Speaker: Prof. Mette Olufsen, Dept. Mathematics, North Carolina State University, and director of the Cardiovascular Dynamics Research Group.

Title: Pulmonary hypertension: fluid dynamics modeling in networks

Abstract:
This study discusses the use of one-dimensional fluid dynamics models for prediction of flow, pressure, shear stress, and wave propagation in pulmonary vascular networks obtained from images. The study presented here is designed for vascular networks, but techniques are applicable to examine similar features in any branched network. The model presented here includes predictions at multiple scales, including the large arteries and veins, arterioles and venules, and capillaries.  The large arteries and veins are represented by a directed graph extracted from computed tomography images, whereas the network of arterioles and venules are represented by structured trees with parameters informed by data. The capillary network modeled using a sheet approximation, is coupled to the network of arterioles and veins in a ladderlike figuration. In the large vessels, we solve the 1D Navier Stokes equations, while in the network of small vessels and capillaries we solve linearized equations, which are coupled to large vessels via outflow boundary conditions.  The model is calibrated to a healthy control, and we investigate how to determine a strategy for optimal treatment for patients with chronic thromboembolic pulmonary hypertension, how to account for uncertainty to model predictions, and how to set up approximate networks mimicking morphometric features extracted from imaging.