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Description
The project seeks to retrieve the local mechanical properties of the walls of the blood vessels treated as an anisotropic elastic medium. The applied method relies on solving an inverse problem of blood flow in distensible conduits. The deformation of the arteries and the blood velocity are measured using an ultrasound scanner. Knowing the Young modulus, all other used stiffness measures can be evaluated. A phantom installation will be built where the direct solution of the computational fluid dynamics (CFD) linked with the elastic deformation of the walls within the Fluid-Structure Interaction (FSI) technique will be validated. To test the reliability of the distension and velocity measurements, measurements of these quantities will be conducted using another set of sensors: 3D deformation scanner and high frequency flow meters. The application of the Uncertainty Quantification will produce the error bounds of the results. Sensitivity analysis applied to the model will identify the crucial variables whose values affect mostly the resulting distension fields. At this stage two blood flow models will be used: a full 3D CFD blood flow model with two ways FSI in its strong form and a 1D flow model in an elastic tube. Both models will be compared in the context of using the simpler model in the final formulation. The comparison will encompass the influence of non-circular geometry, material inhomogeneity. The inverse solver will be applied first on artificial data with simulated and controlled pseudo measurement data. This will result in selecting an optimal inverse algorithm. Then the artificial data will be substituted by real data collected on the phantom installation. The results will be compared with the values of the Young modulus of the conduit measured directly in an independent test. The last step or the project will be a sequence of medical experiments executed on the cardiac artery and retrieving the Young modulus using the already tested inverse procedure.