THE POTENTIAL FIELD-BASED TRAJECTORY PLANNING FOR NEEDLE INSERTION IN A SOFT-TISSUE MODEL

This paper presents a 3D dynamic trajectory planning method for the insertion of a rigid needle into soft tissue. The optimal needle tip orientation was calculated in which applying an artificial potential field method to determine the 3D distribution of repulsive and attractive forces surrounding the target object and adjacent obstacles, e.g. bones, nerves, or arteries. Soft-tissue deformation occurs dynamically and continuously during the needle insertion. The trajectory planning was therefore temporally discretized, and the compartment searching method used in each time step. This trajectory planning method was then validated by a dynamic finite element method (FEM) simulation. The dynamic finite element model is built for the important displacement parameters of deformation node in needle insertion process. The Mooney-Rivlin material model combined with solid cubic element and an explicit center differencing scheme was used to compute the soft-tissue deformation at each time step and dynamically identify the target and obstacle positions. The proposed trajectory planning method can optimize the insertion path to achieve the target position while avoiding obstacles.