Deformation simulation for the needle insertion into liver

The study on the liver deformation during the needle inserted into the target lesion, plays an important role in the robot-assisted liver tumor coagulation therapy system, which impacts the operation simulation, the pre-operative surgical planning, the treatment accuracy, and the success rate. To this end, this paper presents a quasi-static finite element method to analyze the deformation of the soft tissue. According to the force modeling of the needle-insertion, the liver deformation can be divided into two states: the pre-penetration state and post - penetration state. First, both the realistic three-dimensional geometric model and the linear elastic physical model of the liver are established; second, the consecutive dynamic deformation of the liver is decomposed into several discrete quasi-static procedures, followed by the numerical simulation. The simulation results demonstrate the effectiveness and the feasibility of the proposed method.