Endoscopic entire 3D image acquisition of the digestive tract

Because of the narrow viewing angle of the endoscope, it is difficult to grasp the entire image of the digestive tract at once. Therefore, blind spots may occur due to the shape of the gastrointestinal tract, which may result in missed lesions. Virtual endoscopy using CT is the current standard method for obtaining an overall view of the digestive tract. However, since virtual endoscopy detects surface irregularities, it cannot detect lesions without irregularities, including early cancers. In our previous study, we proposed a method of endoscopic entire 3D image acquisition of the digestive tract using a stereo endoscope. However, stereo endoscopes increase the burden on the patient due to the larger endoscope tube. Therefore, in this paper, we propose method of endoscopic entire 3D image acquisition of the digestive tract using a monocular endoscope. The method is as follows: 1) Move the endoscope to capture a series of images of the digestive tract, 2) Estimate the position of the endoscope in each frame by image analysis, 3) acquire 3D points using the continuous images and 4) Reconstruct an entire image of the digestive tract from the 3D point cloud. To confirm the effectiveness of this method, an experiment was conducted using a pattern placed inside a straight tube. The results suggest that this method of endoscopic entire 3D image acquisition of the digestive tract using a monocular endoscope may be able to determine the 3D location of lesions such as early-stage esophageal cancer.