Print Email Facebook Twitter A Novel Approach to Estimating the Material Properties of Atherosclerotic Plaque Tissue Title A Novel Approach to Estimating the Material Properties of Atherosclerotic Plaque Tissue Author van den Berg, Ronald (TU Delft Mechanical, Maritime and Materials Engineering; TU Delft Biomechanical Engineering) Contributor Zadpoor, A.A. (mentor) Tolou, N. (graduation committee) Mirzaali, Mohammad J. (graduation committee) Akyildiz, A.C. (graduation committee) Degree granting institution Delft University of Technology Date 2019-07-18 Abstract The majority of cardiovascular clinical events, which are the main causes of mortality and morbidity worldwide, are caused by atherosclerotic plaque rupture. This biomechanical event occurs when the local plaque stresses exceed its strength. The plaque stresses can be assessed by computational models to predict these events. Current approaches to obtaining the plaque material stiffness properties that these models require as input have large computational costs and are therefore far from being implemented for clinical use. This study aims to develop, validate, and apply for the first time, an approach to obtaining the material stiffness properties of atherosclerotic plaque tissue much faster by employing the virtual fields method (VFM). With this method, the virtual work principle is employed with boundary problem specific, kinematically admissible virtual fields to solve energy balance equations for the material stiffness parameters that are of interest. In this study a method is presented for obtaining the virtual fields for the specific application of intraluminally pressurised atherosclerotic plaque tissue. For the purpose of validation, full field displacement maps were computed at 100 mmHg using Finite Element (FE) models based on histological slides of atherosclerotic plaque tissue. To mimic a realistic situation, the resolution and noise levels of a clinical and high frequency ultrasound scanner were used. Although higher resolution deformation maps with smaller noise levels were shown to provide more accurate results, the VFM-based technique demonstrated good performance for both the high frequency and clinical ultrasound scanner settings tested. VFM was also used in a single case study to estimate the c1 material parameter for a Neo-Hookean incompressible material model in the case of an atherosclerotic human coronary artery. The estimated c1-values for this case were: 21.5 kPa for diseased intima, 13.3 kPa for lipid, and 23.6 kPa for wall tissue. These values were in good agreement with the reported values from literature. In this study, VFM was applied successfully for the material characterization of atherosclerotic plaques for the first time. It is more attractive than current approaches as it is computationally less expensive and has a great potential to be extended for material characterization of even more plaque components than employed in the current study. Subject AtheroslcerosisVirtual Fields MethodMaterial propertiesMechanical characterizationUltrasound To reference this document use: http://resolver.tudelft.nl/uuid:5b325e30-b6af-4993-a662-8189c83275ff Embargo date 2020-07-18 Part of collection Student theses Document type master thesis Rights © 2019 Ronald van den Berg Files PDF Thesis_Report_Ronald_van_ ... 615646.pdf 6.68 MB Close viewer /islandora/object/uuid:5b325e30-b6af-4993-a662-8189c83275ff/datastream/OBJ/view