Adaptive Tetrahedral Mesh Generation for Non-uniformSoft Tissue Simulation

An accurate representation of the object's movement is important in carrying out a realistic simulation. In the case of human soft tissues, depictingtheir deformation realisticallyis not easy because the local changes on the surface of human organs have a substantial influence on their internal structure. Moreover, manipulating an organ is even more difficult when it is composed of multiple materials that are different from one another. A method of representing an organ's interior with uniform-sized tetrahedrons is commonly used. However, this method is problematicbecause theprocessing timeand the memory space need to be expansive. Therefore, we propose a method for simulating human organs that divides the interior into non-uniform tetrahedrons with different sizes depending on the density. When an organ contains tissues with multiple densities, the tetrahedron may deform differently when an external force is applied. Through this experiment, we show that it is possible to represent realistic movements inside an organ model in which low-density soft tissues and rigid tumors are mixed. We designate a few tetrahedrons to rigid tumors with little deformation and more tetrahedrons to soft tissues with a wide range of deformation. The results underscore a more accurate soft tissue simulation for the same number of tetrahedrons.