Study on cardiac biomechanics using idealized and patient-specific models

In cardiac biomechanics, people have been developing a complete model of the patient-specific heart. A finite element bi-ventricular model involves several critical steps. First is the acquisition of patient-specific heart geometry. Second is the definition of material model and its constitutive parameters which is suitable to model the behavior of heart muscle. Third is the integration of fiber orientation of myocardium into the bi-ventricular model. The first objective of this study is to investigate some significant aspects in ventricular biomechanics using a simple model of prolate spheroidal left ventricle (LV). These critical aspects include the geometry of LV, the material model, constitutive parameters and fiber orientations. Results of this simplified model are useful in developing a patient-specific model. For example, parametric study of hyper-elastic material is instructive in determining constitutive parameters of myocardium in a patient-specific model. The second objective of this study is to develop a workflow of building a patient-specific bi-ventricular model. It involves working with experimental data like CT images, DTMRI data and so on. A user defined Fung material model is also reviewed in detail. Two methods of assigning fiber orientation are discussed. Finally, the report points out the future work needed to get a valid patient-specific model which can be useful in research and clinical case.