Research On Vision Navigation And Orientation In Robot Assisted Minimally Invasive Surgery System

At present, research on Robot Assisted Minimally Invasive Surgery is paid more and more attention to by relative researchers. Robot Assisted Surgery or Computer Assisted Surgery's application in Minimally Invasive Surgery is provided with important meaning, such as improving the quality of operation and reducing the damage to patient, as well as optimize surgery path and improving the rates of success. It makes the surgery more secure and more efficient, also can be achieved minimally invasive and accuracy. The Surgical Navigation and Orientation System based on vision is a necessary part of Robot Assisted Minimally Invasive Surgery System. It connects the information in image and the object of operation, which is important for a surgery to improve the precision of the holistic system and complete an operation successfully. The algorithms and experiments are useful in researching for surgical navigation system.The paper researched on Robot Assisted Minimally Invasive Surgery applied in cochlea-transplant surgery. It designed the structure of Robot Assisted Minimally Invasive Surgery system. The paper has made a systematic study on space point localizer with the technology of binocular stereovision. Aim at the characteristic of cranial base surgery, such as cochlea-transplant, this paper excogitated a method of third class navigation and orientation: The first class is made up of several camera which suspend on the top of operating room, it used for watch the scene in operation space; The second class for space point 3D localizer with the double CCD camera based on binocular stereovision. The third class tracks the instruments with one camera connect the microscope and a lamp-house. The paper has achieved the design of operating space localizer based on binocular stereovision, and it is proved by the experiment that the method is feasible. The function of the system is collect image from operating space and achieved the 3D object location for real time.The following work has been completed:1. The dissertation researched the theory of surgical navigation and the technology of orientation. A method of third class navigation and orientation has been presented. It has achieved the design of the Robot Assisted Minimally Invasive Surgery system and the object localizer based on binocular stereovision.2. The technology of camera calibration is studied in detail. Aimed at the requirement of the Robot Assisted Minimally Invasive Surgery system, Tsai's two-stage technology and its improvement are used to calibrate the camera. Based on this,the methods of change focus and screen a set of concentric circles are used to measure the center of image and the uncertainty image scale factor. The theory of stereovision and the techniques in 3D reconstruction are studied in detail. And based on this, the positions of space points can be received. The result of experiments proves that the location error is less than 0.6mm.3. The moulding board of calibration and reference point has been designed. And the paper has made a study on the technique of digital image processing, and completed the image preprocessing and feature extraction by the calculation of the center of objects. 4. The experiments were done and the errors produced in experiment were analyzed. The mathematic model of errors is established. This is the base for the expiation of the errors.The algorithms and experiments are useful in researching for surgical navigation system as well as development of medical robotics.