Research On Laparoscopic Robot And Its Key Technology

With the development of robotics and expand of its application, surgical robots, as one branch of intelligent robot, are coming into our daily life step by step. Applying robots into modern medical field spurs the development of modern mdical technology and is also one of the main developing directions in modern medical equipment. Surgical robot technology and its equipment have gradually become the hotspot in the research field of robotics and have attracted the interest of robotic researchers.Minimally invasive surgery greatly enhances the outcome of surgery by shorting the recovery time and reducing the tissue damages incurred from incision. The use of robot into minimally invasive surgery is gradually accepted by surgeon by virtue of enhancing quality of minimally invasive surgery, reducing labour intensity of surgeon, therefore, the key technology and application related to minimally invasive robot need to be researched further.This work is supported by the National 863 high-tech project"Research on minimally invasive Robot for laparoscopic surgery", On the basis of investigating and synthesizing the current situation of minimally invasive robot, researching on key technology of minimally invasive robot, the integration of exact mechanical engineering, control theory, sensor technology, an innovative laparoscopic robot applying to minimally invasive invironment is developed. The key technology related to the laparoscopic robot has been put into further study.Firstly, the mechanical structure, software and hardware of control system of laparoscopic robot are researched. According to clinical environment of minimally invasive surgery, analysizing the requirement of minimally invasive surgery, a novel laparoscopic robot with seven degree of freedom is developed, the laparoscopic robot has two passive joints to satisfy the constraint of inserting point. Laparoscopic robot is designed by modular method, so it is easy to design and maintain. Open control structure of robot based on motion control board is studied, servo system and corresponding hardware interface board of controller are designed, and software of the control system is developed with object-oriented technology and modularization methodology, design of software fault-tolerant is introduced.Secondly, kinematics of laparoscopic robot under constraint of minimally invasive surgery is researched. The position of incision point is influenced by diaphragm thickness and breath of patient, so a method of calculating incision position is given, position kinematics is present by geometry and linear algebra method, velocity kinematics is solved through constraint conditions under minimally invasive environment. Researching on kinematics of robot not only makes surgeons get cartesian control mode in open surgery, but also settles the foundation of further research on control algorithm and trajectory planning.Thirdly, Motion control technoloty of laparoscopic robot is researched. According to characteristics of minimally invasive robotic surgical tasks, robot motion is divided into four basic actions which are analyzed separately. A novel planning arithmetic for motion under constraint of inserting point is given to improve the position accuracy. Basing on the traditional Gradient Projection Method (GPM), an efficient inverse kinematics solution with position and orientation separate method for redundant robots is introduced.Fourthly, preoperative position planning technology is researched. A strategy of robot base position planning is given by Gradient Projection Method for distance search and combines with dexterity distribution of laparoscopic robot, then an innovative arithmetic of preoperative position planning for laparoscopic robot is given to make surgeon manipulate laparoscope reaching focus.Finally, virtual simulation system for laparoscopic robot is developed by VC and CHAI 3D software, then result of preoperative position planning and motion planning can be simulated in the planform to validate the effective of theory. We conduct some motion control tests of the laparocopicrobot system, and experiment data is analysized. Results of experiments show the effectiveness of correlative theory and provided the basis for further application.