Real-time Deformation of Soft Tissue Internal Structure with Surface Profile Variations using Particle System

Intraoperative observation of tissue internal structure is often difficult. Hence, real-time soft tissue deformation is essential for the localization of tumor and other internal structures. We propose a method to simulate the internal structural deformations in a soft tissue with surface profile variations. The deformation simulation utilizes virtual physical particles that receive interaction forces from the surface and other particles and adjust their positions accordingly. The proposed method involves two stages. In the initialization stage, the three-dimensional internal structure of the surface mesh is uniformly sampled using the particle expansion and attracting-repelling force models whilst simultaneously building the internal particle connections. In the simulation stage, under surface profile variations, we simulate the internal structural deformation based on a deformation force model that uses the internal particle connections. The main advantage of this method is that it greatly reduces the computational burden as it only involves simplified calculations and also does not require generating three-dimensional meshes. Preliminary experimental results show that the proposed method can handle up to 10,000 particles in 0.3s.