Research Of Surgical Instrument For Minimally Invasive Surgical Robot

As the technology of speech recognition, image compression, data transfer, newtype materials and computer control developed, also with the operating stability, accuracy,rapidity and other unparalleled advantages of robot, the growing demand of medicalrobots put more emphasis on surgical robot. The surgical robots are being increasinglyapplied to more complex surgery in different medical fields.The work is supported by “Research on key technology and demonstrationapplication of minimally invasive surgical robot for ventral and laparoscopic surgery” ofthe National863high-tech project. According to functional needs of surgical instruments,structures of surgical instruments and motor drive module have been designed.Mechanics and kinematics analysis/simulation models are founded for surgicalinstrument.Firstly, based on the processes of robot assisted laparoscopic surgery operation, weobtained the structure for the instruments for minimally invasive surgical robot. Theinstrument is divided into2modules, the robot surgical instrument module and motordrive module. Manipulators, decoupling methods, transmission structure and rapidreplacing structure make up instrument module. Manipulators contain grasper, scissorand electrome. Both mechanical design and software control are adopted in decouplingmethods. Cable-driving and pre-tightening structure is adopted in transmission structure.Asymmetrical driver disks play an essential role in rapid replacing structure.Motor drive module whose power is transmitted by cable is consisted of motor part,rotation driving part and interface to surgical instrument. Motor axes are not parallel todriving disk axes. Rotation driving part delivers power to driving disk. Interface tosurgical instrument cooperates with surgical instruments.Finally, surgical instrument are simulated to endure strength. Force analysis issimulated in ANSYS to make sure the stress and displacement of the finger and wrist andto evaluate the strength. Rod stability and bending deformation of instrument staff arealso analyzed. Then driving cable and motors are selected based with analysis before.The transformation matrixes from the basement of instrument driving motor to the fingerjoints of instrument are deduced for kinematical properties. Initial posture of theinstrument is calculated. Coupling movement of the clamp movement is simulated inAdams. The surgical clamp was tested at last.