High-precision Trinocular Vision Localization Method For Surgical Navigation

Computer technology is used to locate position and track of surgical instruments real-time in surgery navigation system,making it possible for doctors to visualize the surgery navigation relative to locations and directions of lesion,reducing surgical injury,and enhancing the quality of surgery.Development of high precision optical positioning system-is then the key and hotspot of surgery navigation.Now,optical position technology is a monopoly by foreign industry,leading to the cost of surgery navigation productions in domestic enterprise higher than foreign industry,making it hard to promote.From the perspective of practical application,this thesis focuses on constructing nearly infrared trinocular vision positioning system.The analysis is presented of classical Pinhole Camera Model as well as the detail analysis and comparison of the strength of TSAI Calibration and Zhang Calibration.An appropriate TSAI calibration method was chosen and applied in accordance with the multi-view stereo vision for system construction.Second,the image feature point extraction and matching reconstruction method was studied.The method of extracting rapid target center based on connected components labeling was proposed.The unique character of the algorithm enabled a high execution efficiency and guaranteed high reliability and appropriate accuracy.Third,the three landmark registration algorithm of surgical was investigated.Throughout the working point of surgical instruments,rotation to get the space coordinates,and then set up the relative position relations of the landmark and working point,complete the registration process.Finally,a multi-view stereo vision based tracking and positioning strategy for surgical instrument is proposes.A multi-view stereo vision system was built by using more than two cameras.The spatial coordinate of a target was reconstructed by using the projection line intersection method.Under the condition of no line-of-sight blocking,spatial coordinate of the target can be reconstructed by extending the projection line equations.Once line-of-sight blocking occurs in one camera,the binocular stereo reconstruction method can be used.The tracking and positioning for a single LED and a self-made multi-point surgical instrument using a self-built trinocular stereo vision system demonstrated the capability of the proposed strategy.This strategy can help to solve the problem of line-of-sight blocking to some extent and avoid the missing of positioning information improving the system reliability with the required accuracy.