System Design And Experiments On The Laryngeal Minimally Invasive Surgical Robot

The surgical robotic system can not only extend the ability of the doctor for surgery, but enhance the quality of the surgery. Facing with the laryngeal minimally invasive surgery with laryngoscope, this dissertation utilizes the design theory of the robotics and the methodology of the mathematics, such as the line geometry and dual number, to design the laryngeal surgical robotic system. It also includes the kinematics analysis, the interference analysis, the master-slave operation analysis, the performance experiments and the animal experiments. The following aspects in the dissertation have been achieved:Based on the quantified analysis of the procedure of the traditional laryngeal surgery with laryngoscope, the design requirements for the laryngeal surgical robotic system are proposed. And then the laryngeal surgical robotic system, which is in the master-slave mode, is designed. The slave manipulator is in the dual arm style which can decouple the position and the posture. In detail, the arm adopts the planar rotating joint structure driven by a cable. The wrist, which includes an interference avoidance mechanism, applies three rotating axes intersecting at one point to minimize the interference problems inside and outside of the laryngoscope. The outer image system uses the binocular stereo vision inspection technique.The workspace and manipulability of the slave manipulator are analyzed. With Monte Carlo method, the reachable workspace of the robotic end-effectors is obtained, that is just its dexterous workspace with determinate orientation. Using the F-norm of the Jacobian matrix, the manipulability of the slave manipulator is analyzed, which has wider application. Furthermore, the maximal manipulability and the maximal area of the co-workspace are taken as the objective function to optimize the key dimension of the slave and its six initial angles. What's more, the ideal layout scheme of the slave for the surgery is achieved.After the basic situation of the interference between the robotic end-effectors and the laryngoscope is analyzed, the method, that uses the line geometry, the dual number and the key points, is put forward to judge the interference. To enhance the speed of the on-line detection of the interference, the interference between the two robotic end-effectors is divided into two kinds. One is defined as the initial judgement, and the other is named as the final judgement. For the interference detection between the robotic end-effectors and the laryngoscope, the four key points and the restricted angles between the axis of the end-effectors and the laryngoscope are adopted. Thus the problem of the interference in the laryngoscope is solved effectively.The kinematic model for the slave and the master of the robot is set up. Based on the vector analytical method, the inverse kinematic equations of the slave are obtained. The direct kinematic equations of the master and the slave are solved with DH method. And the location of the laryngoscope is realized by the binocular stereo vision inspection technique. Through the analysis of the kinematic model, two spacial proportional coefficients on the position and the posture between the master and the slave are determined, among which the former is 4:1, and the latter is 1:1.The performance experiments and the animal experiments are carried out for the robot system. The performance experiments include the slave experiments based on the binocular stereo vision inspection technique, the master interference experiments in the virtual environment, and the master-slave operating experiments. These experiments effectively validate the method of detecting the interference, the fast location of the slave, and the master-slave operation. The system uses a pig to complete the animal experiments, which include the whole procedure of cutting its vocal cords. The successes of the animal experiments show the integrality of the robotic system and the feasibility of the robotic technology.