Performance Improvement for Two-Lens Panoramic Endoscopic System during Minimally Invasive Surgery

Abstract

One of the major challenges for Minimally Invasive Surgery (MIS) is the limited field of vision (FOV) of the endoscope. A previous study by the authors designed a MIS Panoramic Endoscope (MISPE) that gives the physician a broad field of view, but this approach is still limited, in terms of performance and quality because it encounters difficulty when there is smoke, specular reflections, or a change in viewpoint. This study proposes a novel algorithm that increases the MISPE’s performance. The method calculates the disparity for the region that is overlapped by the two cameras to allow image stitching. An improved evaluation of the homography matrix uses a frame-by-frame calculation, so the stitched videos are more stable for MIS. The experimental results show that the revised MISPE has a FOV that is 55% greater, and the system operates stably in real time. The proposed system allows a frame rate of 26.7 fps on a single CPU computer. The proposed stitching method is 1.55 times faster than the previous method. The stitched image that is obtained using the proposed method is as similar as the ground truth as the SURF-based stitching method that was used in the previous study.