Numerical simulations of the flow in thoracic aortic aneurysms are carried out by using the open-source tool SimVascular and considering patient-specific geometries, obtained through in-vivo imaging. One of the main issues in these simulations is the choice of suitable boundary conditions, modeling the organs and vessels not included in the computational domain. The current practice is to use outflow conditions based on proximal resistance, capacitance and distal resistance (three-element Windkessel model), whose values are tuned to obtain a physiological behavior of the patient pressure. However, it is not known a priori how this choice affects the results of the simulation. A quantification of the impact on the numerical simulation results of uncertainties in the values of the Windkessel model parameters is carried out by using the generalized Polynomial Chaos approach. Different patient-specific geometries are considered, characterized by a different size of the aneurysms, and the effect of wall compliance is also investigated. We analyze the impact of the uncertainties in the selected outflow parameters on the time-averaged wall shear stress and on the oscillatory shear index, which are commonly used as hemodynamic descriptors.
|Titolo:||Uncertainty quantification in numerical simulations of the flow in thoracic aortic aneurysms|
|Anno del prodotto:||2016|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|