Active Model with Orthotropic Hyperelastic Material for Cardiac Image Analysis

Abstract

Meaningful physiological models are important for studying cardiac physiology. For cardiac image analysis, the models used should be detailed enough to describe the macroscopic physiological behaviors, but should not be too complicated for the inverse problems. To achieve this goal, we propose to use an orthotropic hyperelastic biomechanical model, which has only seven parameters but was reported as the best among the five tested well-known models in a comparative study. Combining with the active contraction forces provided by electromechanical models, the cyclic cardiac dynamics can be available to provide the physiological foundation for cardiac image analysis. To facilitate the complicated inverse problems, the system is implemented under the Cartesian coordinate system, and we propose the corresponding cardiac specific boundary conditions for anatomically realistic deformations. Experiments with analytical solutions were performed to verify the correctness of the implementation, and cardiac cycles were simulated to verify the physiological plausibility of the proposed model.