Real-time multi-physics modeling of radio-frequency electrosurgical procedures

Abstract

This approach provides greatly increased visual resolution of thermal effects, yet remains physically accurate. However, a major limitation of this approach is that it still requires dynamic triangulation to provide sub-finite-element graphical rendering. To overcome this issue, we propose a novel physics-driven level set approach to capture the interfacial evolution of tissue damage to reduce meshing and re-meshing complexity. An important aspect of this work is the derivation of the level set evolution equation from the Second Law of Thermodynamics, which is consistent with Griffith’s fracture evolution criterion. The damage parameter that determines the interfacial evolution of tissue damage is characterized by solving an inverse problem that seeks to minimize the difference between the predicted and experimentally measured topological information, i.e. signed distance of a spatial point from the damaged interface. Controlled electrosurgical experiments are performed on the fresh ex vivo porcine liver to obtain the topological information of damaged tissue. Example problems are shown to simulate tissue dissection with a fixed and moving active electrode.