Bionic Design And Puncture Control Of Rigid Flexible Cooperative Interventional Robot

Puncture interventional surgery is a series of diagnosis and treatment operations for the focus area of patients through the cooperation of two hands.It has the characteristics of high safety coefficient,small wound,fast recovery and flexible operation.But traditional operation method relies on doctor experience and it is easy to cause fatigue.The robot human-machine cooperation can help doctors to implement the puncture interventional surgery,which can effectively improve the safety,controllability and stability of the puncture operation.Many creatures in nature have shown good survival characteristics according to their own rigid and soft cooperation.However,the current research of cooperative robots is mostly focused on the cooperation of both arms and is mostly used in the industrial field;In addition,rigid needle is difficult to avoid obstacle during interventional operation,and flexible needle is easy to damage soft tissue.In this dissertation,the target of soft tissue precision puncture is to reduce the damage to soft tissue and improve the precision of puncture,and to carry out the research of puncture intervention based on bionic design concept,which is based on the cooperation of rigid manipulator to control the target movement of soft tissue target and flexible needle.The results provide some theoretical and experimental basis for the application of rigid and soft cooperative interventional robot precise puncture operation.According to the existing problems and actual needs of clinical puncture interventional surgery,the design requirements of rigid flexible cooperative interventional robot are obtained;Inspired by the process of leech piercing and sucking,based on the idea of bionic design and modular design,the robot body is selected,and the needle feeding mechanism and five degree of freedom rigid manipulator of the rigid flexible cooperative interventional robot are designed;The kinematics and workspace of the rigid manipulator are analyzed by MATLAB/Simulink software.The stress and deformation of the weak parts of the rigid flexible cooperative interventional robot are analyzed by ANSYS/Workbench software.The results verify that the designed structure and selected materials meet the clinical needs.The hardware and software structure of the control system of the rigid flexible cooperative interventional robot is designed by using the upper and lower computer control mode.Based on the analysis of the force of puncture needle in the process of soft tissue puncture,the discrete method is used to analyze the process of puncture needle.The improved virtual coil spring model is used to simulate the bending deformation of flexible needle for each discrete unit;In order to make the calculated results of the model closer to the actual bending effect,the bending results of different discrete degrees under the model are analyzed,the optimal discrete length is obtained,and the feasibility of the proposed model is proved.Combined with the motion characteristics of the flexible needle,the puncture path of the flexible needle is planned based on the improved asymptotically optimal fast expanding random tree(RRT *)algorithm,and the MATLAB software is used to simulate the path planning algorithm,and the results verify the superiority of the algorithm.Due to the difficulty of soft tissue modeling and large individual differences,a method of soft tissue target movement controlled by rigid manipulator based on orthogonal binocular vision is proposed.Firstly,the robot model,camera model,soft tissue model and deformation feature model are established.Then,the mapping relationship between the motion of the rigid manipulator and the soft tissue deformation features detected by vision is established,and the adaptive controller is used to achieve the control goal.Finally,the image processing method is used to realize the target detection and tracking,and the feasibility of the proposed method is verified by experiments.Based on the operation flow of clinical puncture operation,the puncture process of cooperative interventional robot is designed.According to the principle of mosquito vibration puncture,a vibration puncture method suitable for rigid flexible cooperative interventional robot is designed,and the puncture effect of the method is evaluated by experiments.In order to reduce the soft tissue damage and improve the puncture accuracy,the position relationship among the entry point,target point and obstacles in the plane is analyzed,and a rigid flexible cooperative puncture strategy based on intelligent block search and improved RRT * algorithm is proposed.The experimental platform of rigid flexible cooperative interventional robot puncture is built to verify the feasibility and effectiveness of the rigid flexible cooperative puncture strategy.