An Experimental And Theoretical Model For The Passive Biomechanical Properties Of The Intact Heart

Previous attempts to model the biomechanics of the heart have either imposed restrictive simplifications on geometry or have ignored the inherent complexities of the tissue. The present work intends to capitalize upon advances in cardiac imaging and material modelling to overcome some of these limitations so that the passive biomechanical properties of the intact heart may be quantified in-vivo. State-of-the-art nuclear magnetic resonance imaging (MRI) has made it possible to image the beating heart in extraordinary detail. This technology has been employed in obtaining threedimensional intact measurements of cardiac geometry synchronized with ventricular pressure. Fiducial markers suitable for cardiac MRI have been developed to assist the determination of motion from MR images. The present research also initiates a systematic formulation of constitutive equations for the passive mechanical behavior of intact myocardium - based on first principles of continuum mechanics. This will serve as a sound foundation upon which more comprehensive models may be built, and will hopefully lead to improved understanding, diagnosis, and management of cardiac disease.