Research On Force Sensing Microinstrument Of Laparoscopic Surgery

Laparoscopic surgery is a kind of minimally invasive surgery(MIS), compare to open surgery, laparoscopic surgery has many benefits, including reducing pain and trauma, reducing loss of blood, reducing risk of wound infections, having shorter hospital stays. But the instruments of laparoscopic surgery also have many disadvantages, such as not having enough degree of freedom, the friction between the instruments and teocar, lack of force feed back. The instruments of robot surgery system can solve some problem above. But lack of force feedback and limited flexibility are the main problem of the instrument of the robot surgery system. In this paper, the subject will research the instruments of robot surgery system for laparoscopic surgery based on full spectrum with research status and development at home and abroad.Based on the analysis of the motion of micro instrument surgery equipment and work space of the laparoscopic surgery, combined with the characteristics of laparoscopic surgery, a new micro instruments which have the ablity of force feedback has been designed. This paper adopted the cross girder, which has high rigidity and high sensitivity, as the structure of the sensor. The best parameters of the structure was got by mathmatic modeling and simulating of the struture. The position and arrangement of the srain gages have confirmed based on the design goals. This paper design a calibration system for the three-dimensional force sensor, and analysis the error of the calibration system according to the error theory, then calculate the maximum error of calibration system.This paper have conducted investigations in the static characteristics of the miniature six axis force/torque sensor. And a equipment of Calibration has been designed and produced. The calibration error of the calibration system has been analysed. This chapter provides a theoretical basis to achieve force feedback in the future.A new endo-wrist and the actuator of the micro instruments design have being designed. The micro instrument have 7 DOF, such as pitch, yaw, rotate of the shaft, open and close of the elastic separating plier. A quickly change interface have been designed for the transmission of power and signal.