Accurate biomechanical modeling of liver is of paramount interest in pre-operative planning or computer-aided per-operative guidance. Since the liver is an organ composed of three different components (parenchyma, vascularization and Glisson's capsule), an efficient and realistic simulation of its behaviour is a challenging task. In this paper we propose a complete model of liver where each component is modelled with different type of finite elements chosen according to the nature and mechanical properties of the component. The elements of different types are coupled via mechanical mapping encoded in the global stiffness matrix. In the result section, we first focus on simulation of Glisson's capsule using constant-strain triangular elements: we compare the model to a detailed non-real-time model and also reproduce previously published aspiration test showing the importance of the capsule. Finally, we demonstrate that the proposed complete liver model can be used in a real-time simulation.
