An ORB-SLAM3-based Approach for Surgical Navigation in Ureteroscopy.

In ureteroscopy a flexible ureteroscope is used to inspect the kidneys and the ureters. In this context, we investigate robotic solutions that leverage recent developments from Simultaneous Localization and Mapping (SLAM) to provide a 3D map of the organ to be explored and the ureteroscope's pose. With this aid, the surgeoncan navigate through the organ more precisely. Additionally, for the final organ inspection, the risk of missing certain regions of the organ is minimized. In this paper, we propose a visual, monocular SLAM system based on ORB-SLAM3 that is able to estimate the pose of the ureteroscope's tip. In order to fulfill this task, we introduce two pre-processing steps. The first one aims at increasing the contrast of the image and the second one helps to avoid detecting features in non-desired regions (e.g. reflections). Additionally, we extend ORB-SLAM3 with A-KAZE and SuperPoint features and compare their performances to ORB features. The proposed method is evaluated in two experiments. The first experiment shows that we are able to estimate the trajectory of the ureteroscope and the map of a synthetic kidney with low errors. The second experiment shows that the method also gives promising results in cystoscopy.