Quantifying the mechanical properties of myocardium in cases of heart failure by preserved ejection fraction (HFpEF)
About this project
Preserved Ejection Fraction (pEF) is a condition in which the heart’s ability to pump blood throughout the body is reduced. It is characterised by a stiffening of the myocardium (cardiac tissue), leading to the heart not relaxing to its full size before contracting for the next heartbeat. This results in a reduction of the actual volume pumped by the heart and, consequently, pEF is present in approximately 50% of people who experience heart failure. The aim of this project is to determine the composite mechanical properties of myocardium that lead to pEF, and identify which component (e.g. titin) dominates these properties. An ongoing area of interest in the study of pEF is the exact way in which the properties of the myocardium change to increase the heart’s relaxation time. A better understanding of how much various tissue properties can change or which specific layers of tissue have the greatest effect on the relaxation could assist in directing treatments towards these problem areas, and focus research on the biological factors that create these changes or effect these areas. This research will be computational in nature. A coupled computational fluid-solid dynamics model will be used to create a digital twin of representative biological flow configurations. The lattice Boltzmann method will be used to model transient blood flow as a non-Newtonian Kuang-Luo fluid, while the finite element method will be used to represent the composite myocardium as a pseudoelastic, orthotropic material. A significant amount of research has been undertaken in computational haemodynamics, while more recent research has been conducted to experimentally determine the material properties of healthy myocardium. By modelling this coupled fluid-solid system, a better understanding of the exact material property changes that are associated with pEF can be achieved, as well as the possibility of exploring treatment methods.
The outcomes of this project will include (a) new knowledge on the mechanical interaction of blood and myocardium during pEF and (b) a novel computational tool that can be used to further investigate clinical issues related to heart failure. By reproducing the macroscopic flow conditions present in pEF it will be possible to identify which component of the myocardium is contributing most significantly to the abnormal behaviour. In turn, it will quantify mechanical properties of the abnormal tissue(s) and guide further research into the biological origins of these changes. This is currently unknown. The computational framework that is developed in this project will build on the extensive codebases in multiphase fluid mechanics and solid mechanics that have already been developed by the research groups of Dr Leonardi and A/Prof Ray. The novel tool that results from this work will be extensible and applicable to the investigation of a range of clinical problems related to the pulmonary system in the human body (e.g. the rupture of artherosclerotic plaque).
Information for applicants
A strong understanding of fluid mechanics and solid mechanics and experience with computational modelling/simulation.
Experience with code development and computational fluid dynamics, especially the lattice Boltzmann method.
Expected qualifications (Course/Degrees etc.)
Degree in mechanical engineering, biomedical engineering, mathematics or applied physics.
This project is open to students with a background in mechanical engineering, biomedical engineering, mathematics or applied physics. Interest and demonstrated competence in fluid mechanics, computational fluid mechanics and software engineering would be of tremendous benefit to the project.