The mechanical function of the heart is governed by the contractile properties of the cells, the mechanical stiffness of the muscle and connective tissue, and the pressure and volume loading conditions on the organ. We have shown that heart muscle has a complex layered, fibrous 3D architecture that has a profound effect on its mechanical behaviour.
Auckland Bioengineering Institute
Cardiac Mechanics
Predicting normal and abnormal mechanical processes of the heart
Accurate Finite Element models of heart shape, tissue architecture and mechanical properties have been developed to realistically predict normal and pathological mechanical processes.
Tissue testing devices have also been developed to characterise the mechanical properties of heart muscle during extension, compression and shear.
Developing better analytical techniques to improve diagnosis
One area of active research is the development of better material laws that can be used to interpret in-vitro and in-vivo tissue behaviour. Sophisticated analysis methods are being developed for the understanding of diastolic and systolic mechanisms of dysfunction. These techniques will allow improved diagnosis of patients and evaluation of treatment.
Mechanical orthotropy of cardiac tissue
Heart muscle fibre and connective tissue organisation gives rise to mechanical behaviour that varies depending on the loading orientation. This is known as mechanical orthotropy of cardiac tissue.
Tissue stretch versus load
Recordings of tissue stretch versus load (mechanical stress) registered against the fibre-sheet microstructural directions provide the necessary information to characterise the mechanical properties of heart muscle and the construction of microstructurally-based material laws.
Computational model of the ventricle
An anatomically accurate computational model of the left and right ventricles, including quantitative descriptions of the muscle architecture, allows application of realistic boundary conditions (pressure, volume) and orthotropic mechanical properties.
Heart cycle simulations
Heart cycle simulations validated against clinical and experimental recordings of organ deformation (from MRI, ultrasound, etc) provide regional estimates of ventricular wall stress. Increased wall stress is known to be correlated with oxygen demand and used as a marker for disease.
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