Research On Opto-mechanical Design And Camera Calibration Of High Definition Three Dimensional Laparoscopic System

The two dimensional (2D) laparoscope have capable of high-definition video real time outputting, however the loss of depth perception is the system defect due to2D vision. The three dimensional (3D) laparoscope with depth perception compare to2D laparoscope can improve the efficiency, shorten the learning curve, and reduce the operating time. Because of such merits and needs of3D laparoscopes, many medical imaging equipment manufacturers have developed the related technology and products for many years. But in China there still have no product of3D laparoscope.The purpose of this paper is to design a high-definition3D laparoscope system and do some research on high-definition3D laparoscope system. The research content includes: the design of opto-mechanical system of3D laparoscope, binocular camera calibration of high-definition3D laparoscope system, depth measuring experiment based on high-definition3D laparoscope system. The main work includes the following three aspects:(1) Analyzed the opto-mechanical design of3D laparoscope on the market, compared the difference of monocular stereo vision system and binocular stereo vision system, and finalized the design plan of the high-definition3D laparoscope system.(2) Studied on the different principal of camera calibration, considering the specificity of our high-definition3D laparoscope system, presented an new camera model. Based on the new camera model, we use the OpenCV to accomplish our camera calibration of high-definition3D laparoscope system.(3) Proposed a new method of depth measurement based on spatial geometry theory, performed the depth measurement with our high-definition3D laparoscope, at the measuring range10mm～150mm, the average error is under1.13mm or3%, solved the problem of big error emerged when using the stereo triangulation method or the quadratic fitting method.The optical performance of the high-definition3D laparoscope system has reached the international advanced level, and the size of the system is relatively small. The system has the ability to real time outputting dual channel1080P video. With the presented new special camera model, the system calibration based on OpenCV has the high accuracy. The depth measuring method based on spatial geometry theory has been proposed at the first time, and the accuracy of the measurement is well proved. Also the new method basically can be applied to any calibrated binocular vision system.