Research On The Puncture Needle Trajectory Planning Based On Image Guided Surgery

The paper takes the robot-assisted percutaneous surgery as the object of study.The trajectory planning of flexible needle in the complex environment of human body is researched extensively in this thesis.Therein an improved algorithm for the defects of the algorithm is proposed.We also study the extraction of human organ information.In addition,the target displacement caused by the interaction between the needle and the soft tissue is analyzed.The flexible needle puncture experiments are conducted combined with the flexible needle steering algorithm.The results of the study will help doctors to predict the target displacement,and complete the preoperative path planning accurately and quickly.This research has great significance to the success of the operation.Firstly,we analyze the causes of the target displacement including flexible needle deflection and soft tissue deformation.The flexible needle deflection model is established,and its deformation is obtained by numerical simulation.The material parameters of the biomimetic tissue made by ourselves are studied as the input of the finite element analysis and combined with the flexible needle deflection to research the deformation of the tissue,so as to provide a simple method for predicting the target displacement.Secondly,the traditional artificial potential field algorithm and its advantages and disadvantages are analyzed,and an improved algorithm is proposed.According to the information of obstacles in the complex environment of the human body,this paper studies the manual segmentation and the method of extracting the information of the pelvic organs.The extracted information is visualized and the path planning of the flexible needle is carried out in this environment by using the improved artificial potential field algorithm.The planning results show that the trajectory can avoid the obstacles and the improved method can keep the efficiency of the algorithm.The experimental results prove that the improved algorithm can solve the problem that the robot trapped in the minimum potential energy well,and can escape successfully under the premise of preserving the advantages of the original method.Finally,the duty cycle algorithm of flexible needle steering has been studied and the needle steering experiment table and point identification tracking test table are established.By comparing the simulation results with the experimental results,the possible reasons for the errors are analyzed and the solutions are given.