Study Of Master Slave Robot Catheter System For Minimally Invasive Surgery

This subject is supported by national natural science fund project (61105099), and thename is “Study of Modeling and Controller of Master Slave Robot Catheter System forSoft Catheter”. Minimally Invasive Surgery (MIS) is getting more and more popular indiagnosis and surgery. Compared with the traditional operation, it has so many advantagessuch as minimal trauma, pain controllable, fast recovery and less recurrence. However,conventional MIS has many disadvantages: in order to insert catheters successfully, thedoctors not only needed to have rich knowledge and practical experience, but also neededto be very well trained; during the operation, the doctors have to work around X-raycamera, so the X-ray damages the health of the doctors; the doctors’ misoperation may behurt patients. Robotic Catheter System is a best choice to solve these problems. Thedoctors can control the master hand outside of the operating room, and then the controlsignals are sent to the slave hand. When the slave hand receives the control signals, it willdrive catheter to the planned position. Robotic Catheter System not only contributes to thehealth of the doctors, but also to the security of the MIS for the patients.First of all, on the base of reading a lot of related literature at home and abroad, thisthesis discusses the topic research background and the present national and internationalresearch situation of Master Slave Robot Catheter System (MSRCS) for MIS. The existingproblems are also analyzed, and then the purpose and meaning of the subject are providedin this chapter. The structure of the MSRCS for MIS is introduced, and then we set up thedynamic model of slave hand, including the dynamic model of the axial movement and therotational movement. On the other hand, the basic principle of master-slave teleoperationrobot system is discussed, and we also give detailed explanations of the dynamic model ofa1-DOF master slave teleoperation system. In the end, teleoperation robot system’sstability, transparency and the environment for slave hand are detailed in detail.Secondly, a PID controller is designed for improving the tracking performance ofslave hand.Simulation results show that traditional PID controller used in the MSRCS will cause large overshoot or poor stability, and it may be hurt the patients. So an adaptivefuzzy PID controller is designed to reduce the overshoot, and to improve the robustnessand accuracy of tracking performance. Results obtained from simulation show that thedesigned adaptive fuzzy PID controller has better performance in tracking the master’ssignal compared with traditional PID controller, and the robustness and accuracy are alsoimproved.At last, in view of the reality that system performance is affected by communicationtime delay between the master and slave. The sliding mode control in teleoperation robotsystem is discussed. On the one hand, a sliding mode controller by using of saturationfunctions is designed to solve the problem. The simulation results show that the designedcontroller carries out force tracking and position tracking between master and slave ofteleopration systems. On the one hand, a fuzzy slide mode controller is designed forsolving chatting problems, simulation results show that position tracking between masterand slave of teleopration systems is improved, and the designed controller has a strongrobustness.