BodySLAM: A Generalized Monocular Visual SLAM Framework for Surgical Applications

Endoscopic surgery relies on two-dimensional views, posing challenges for surgeons in depth perception and instrument manipulation. While Simultaneous Localization and Mapping (SLAM) has emerged as a promising solution to address these limitations, its implementation in endoscopic procedures presents significant challenges due to hardware limitations, such as the use of a monocular camera and the absence of odometry sensors. This study presents a robust deep learning-based SLAM approach that combines state-of-the-art and newly developed models. It consists of three main parts: the Monocular Pose Estimation Module that introduces a novel unsupervised method based on the CycleGAN architecture, the Monocular Depth Estimation Module that leverages the novel Zoe architecture, and the 3D Reconstruction Module which uses information from the previous models to create a coherent surgical map. The performance of the procedure was rigorously evaluated using three publicly available datasets (Hamlyn, EndoSLAM, and SCARED) and benchmarked against two state-of-the-art methods, EndoSFMLearner and EndoDepth. The integration of Zoe in the MDEM demonstrated superior performance compared to state-of-the-art depth estimation algorithms in endoscopy, whereas the novel approach in the MPEM exhibited competitive performance and the lowest inference time. The results showcase the robustness of our approach in laparoscopy, gastroscopy, and colonoscopy, three different scenarios in endoscopic surgery. The proposed SLAM approach has the potential to improve the accuracy and efficiency of endoscopic procedures by providing surgeons with enhanced depth perception and 3D reconstruction capabilities.