Application of Hyperelastic-based Active Mesh Model in Cardiac Motion Recovery

Abstract

Considering the nonlinear hyperelastic or viscoelastic nature of soft tissues has an important effect on modeling results. In medicalapplications, accounting nonlinearity begets an ill posed problem, due to absence of external force. Myocardium can be consideredas a hyperelastic material, and variational approaches are proposed to estimate stiffness matrix, which take into account the linearand nonlinear properties of myocardium. By displacement estimation of some points in the four-dimensional cardiac magneticresonance imaging series, using a similarity criterion, the elementary deformations are estimated, then using the Moore–Penroseinverse matrix approach, all point deformations are obtained. Using this process, the cardiac wall motion is quantized to mechanicallydetermine local parameters to investigate the cardiac wall functionality. This process was implemented and tested over 10 healthyand 20 patients with myocardial infarction. In all patients, the process was able to precisely determine the affected region. Theproposed approach was also compared with linear one and the results demonstrated its superiority respect to the linear model.