3D Motion Planning for Robot-Assisted Active Flexible Needle Based on Rapidly-Exploring Random Trees

An active flexible needle is a self-actuating needle that can bend in the tissue and reach the clinical targets while avoiding anatomic obstacles. In robot-assisted needlebased medical procedures, motion planning is a vital aspect of operations. It is challenging due to the nonholonomic motion of the needle and the presence of anatomic obstacles and sensitive organs that must be avoided. We propose a novel and fast motion planning algorithm for the robotassisted active flexible needle. The algorithm is based on Rapidly-Exploring Random Trees combined with greedyheuristic strategy and reachability-guided strategy. Linear segment and relaxation of insertion orientation are taken into consideration to the paths. Results show that the proposed algorithm yields superior results as compared to the commonly used algorithm in terms of computational speed, form of path and robustness of searching ability, which potentially make it suitable for the real-time intraoperative planning in clinical operations. 