The Structural Design Of Surgical Instrument For Celiac Minimally Invasive Surgical Robot

Minimally invasive surgery has the advantage of reducing trauma to the body, shortening wound healing time, rapid recovery after operation, low cost, significantly shortening hospital stay, and appling robotic technology into minimally invasive surgery can improve surgical quality and reduce medical labor intensity, which is physicians have gradually accepted. Minimally invasive surgical robot technology has become a hot topic in medical robotics.This subject which is supported by the National 863 high-tech project Research on minimally invasive robot for laparoscopic surgery , will research on the instrument structure of minimally invasive robot. Instrument could hold, pull and cut the abnormal tissue. There are many types of surgical instruments, This subject will research on needle holders forcep.According to analyzing the abdominal surgery and operating force of instrument,the overall structure of the robot manipulator is determined. And the design requirements of instruments are presented, which results in the configuration problem of surgical instruments. surgical instrument is composed of the end effector, gearbox and the base. And the configurations of the three modules are selected, which conclude the overall configuration of surgical instrument.The specific structure of the surgical instrument is designed in detail, and the surgical instrument has four degrees of freedom(DOF) which are the operating rod rotation, the wrist rotation, holding and pitching; and the detailed design of each module is carried out. This subject uses the structure of planetary gear drive compensate the fingers coupling movement caused by the wrist rotation, and the specific implementations of wire transmission are elaborated; the wire stress is analyzed and the type of the wire is selected; the gear train is designed.The virtual prototype of surgical instrument is established used by ADAMS software to simulate and analyze the kinematic and dynamic performances. Forward kinematics simulation is to verify the correctness of instrument's drive principle; and according to inverse kinematics simulation, the velocity curves and displayments of ralated joints are obtained; from the dynamic point of view, the torque curves and power curves of the motor reducer output shafts are obtained, which are used to complete the selection of drive motor.Experimental research and performance testing of surgical instrument are carried out. The 4-DOF movements are carried out, and surgical instrument controlled by master manipulator is realized.