Movement Method Study On Multi-arm System Of Minimally Invasive Surgical Robot Under Laparoscope View

The combination of robotics and surgical techniques promotes the development of themedical engineering, compared with the conventional minimally invasive surgery, therobot-assisted minimally invasive surgery significantly improves the operative security andalleviates the patient’s pain and mental burden.In the minimal invasive general surgery, the doctor needs to adjust the operation field inreal time. The desired operation field performs up and down, sideways and front-to-backmotion based on the current vision information of the laparoscope, which facilitates the doctorto operate habitually in normal thinking; Since a series of operations with the microinstruments during the surgery are on the basis of the current view provided by thelaparoscope, the moving base coordinate system of the micro instruments changes with thechanging laparoscope. The current poses of the micro instruments are based on the currentlaparoscope vision coordinate system, while their desired poses are based on the current posesand the kinematic parameters (derived from the doctor actual requirements).In order to computer the motion of the micro instruments precisely under the currentview when the laparoscope keeps moving, a method for the coordinated movement of themulti instrument arms system based on the laparoscope dynamic vision is greatly needed.Firstly, introduce the mechanical structure characteristics of the instrument arms in therobotic system, establish the kinematics model of the instrument-holding arm and thelaparoscope-holding arm of the minimally invasive surgery robot. Computer the direct andinverse kinematics of the instrument-holding arm and the laparoscope-holding armrespectively, and the computation are verified by Simulink simulation.Then, with the surgery procedure of the minimally invasive surgery system, a method ofmulti instrument arms coordinated movement under the laparoscope view is proposed,establish the coordinate transform relationships among the coordinate systems involving theinstrument-holding arm base, the laparoscope-holding arm base, the micro instrument grippedby the instrument-holding arm and the laparoscope gripped by the laparoscope-holding arm,calculate the inverse kinematics of the laparoscope and the micro instrument in thelaparoscope instrument coordinate system respectively, and the corresponding calculation issimulated by Simulink, the movement algorithm solves the coordinated movement of the multi instrument arms system under the dynamic view of the laparoscope.Finally, a trajectory planning algorithm for optimizing the actual end-effector trajectoryof the instrument arm in the multi-arm system is proposed, which results in a smoother andmore accurate end-effector trajectory. The proposed algorithm is simulated by theMatlab/Simulink and SimMechanics and its correctness is validated by the data results.