Type Synthesis On Flexible Instrument Of MIS Robot And The Study Of Master-slave Control Strategy

With the development of robotic assisted surgery, robot with flexible instrumentis gradually applied in surgery, especially in Single Port Surgery (SPS) and NaturalOrifice Translumenal Endoscopic Surgery (NOTES). In this dissertation, I focus onthe flexible robot design, including the flexible structure analysis, type synthesis,master-slave control mode and experiments. Several contributions in this dissertationare related as follow.Based on the design of ureterscopic robot and intracardiac echocardiography(ICE) robot in this dissertation, several points about flexible robot design are analyzed.The cable driving and transmission configuration, the kinematics of different DOFs offlexible instruments are analyzed. I also proposed a stiffness enhanced method forflexible instrument by driving the instrument from handle and flexible segment at thesame time. According to the experiences of doctors and the studies of differentsurgical robot, the requirements of mechanical and control design for flexible robotare also discussed.A novel type synthesis method based on constraint screw theory is proposed inthe design of closed loop cable driving (CLCD) mechanism for flexible robot. Themechanism can ensure that the total path length of driving cable is constant. Afamily of CLCD mechanisms is obtained by using the proposed method.Taking one typical CLCD mechanism obtained by using type synthesis methodas example, a surgical robotic instrument and flexible instrument can be constructedafter the CLCD mechanism improved and optimized. The developed flexibleinstrument is applied in the design of a novel single port surgical robot.To overcome the disadvantages of existing master-slave surgical robot, includinghigh cost, cumbersome mechanical design, casing surgeon fatigue, et al., a newmaster-slave operating method based on electromagnetic tracing mechanism isproposed. The new operation mode can make it possible for surgeon to use theoperation of open surgery in robotic assisted surgery. Surgeon doesn’t need train for along time any more, and can be more intuitive and immersed in the surgery. Toguarantee the safety in robotic surgery, a safety master-slave tracking strategy for thenew Master-Slave control mode is also analyzed. Experiments have been carried out to calibrate and test the developedureteroscopic robot. The relationship between flexion angle and driving angle inureteroscope is calibrated to avoid the influence of cable slack. The developedureteroscopic robot is used to do the operation test and animal experiment to comparewith the manual operation. The stiffness enhanced method for flexible instrument isverified by the experiment. Some experiments are done to verify the dexterity andpossibility of the obtained flexible instrument. The master-slave tracking experimentis also done to verified the possibility, stability and safety of the novel operationmode.