Estimation of myocardial material parameters in developing zebrafish using inverse finite element analysis

The zebrafish is a widely used model for studying cardiac development. It is well known that mechanical forces are essential stimuli for the proper development of the heart. Multiphysics in silico models of the zebrafish heart, combining fluid-structure interaction, electrophysiology, and micromechanical tissue models, are powerful tools to quantify mechanical forces with high spatiotemporal precision, and they promise to greatly increase our understanding of cardiac mechanobiology. However, such models rely on accurate estimates of the material parameters of the zebrafish heart wall, which are difficult to obtain experimentally due to its small size. We address this limitation by applying an inverse finite element (FE) analysis to estimate the in vivo material parameters of the zebrafish ventricle. First, an image-derived FE model of the ventricle is coupled to a 0-D model of blood flow to simulate diastolic filling. Then, material parameters of the FE model are found using an optimization routine by matching simulation results to in vivo videos of the zebrafish ventricle. With the optimized parameters, the model shows good agreement with the in vivo deformation of the ventricle, demonstrating the viability of our approach. This work is supported by grants from the NIH and NSF.