Sarascope 2.0: A Novel Endoscopic System for Robotic Minimally Invasive Surgery

In Robotic Minimally Invasive Surgery (RMIS), ac- curate intra-operative depth perception is critical for complex maneuvering and is a prerequisite for advanced computer-assisted interventions, such as Augmented Re- ality (AR) and autonomous task execution . While stereoscopic endoscopes address the limitations of monocular systems, they are severely constrained by the anatomical access ports (trocars). Conventional stereo endoscopes must fit both optical channels within a 10 mm or 12 mm diameter shaft, resulting in a narrow stereo baseline (typically <8 mm). This intrinsic limi- tation leads to poor triangulation accuracy, especially at increasing working distances. Several research efforts have explored methods to overcome this limitation. Early work in computer vision investigated the concept of variable-baseline stereo, demonstrating that increasing the distance between viewpoints significantly improves depth estimation accuracy, particularly in mid- to long- range scenarios. However, translating these principles into endoscopic systems remains challenging due to strict size and access constraints. Recent developments in both industry and academia aim to overcome fixed-baseline limitations in endoscopy. The Vicarious Surgical platform utilizes a multi-camera, distributed viewpoint architecture to broaden 3D perception. Similarly, Salcudean et al. (UBC) have developed ’pickup’ stereoscopic cameras that can be repositioned intra-operatively to optimize sensing baselines and reconstruction accuracy. Building upon previous work in endoscopy, we introduce Sarascope 2.0, a completely new concept focused on overcoming the baseline limitation. Unlike standard fixed-geometry endoscopes, Sarascope 2.0 features a rigid shaft with a deployable distal tip. Through a novel mechanical “tilt” actuation, the distal cameras rotate outwards upon reaching the surgical site, achieving a wide extended baseline of the stereo cameras of 2.5 cm. This significant increase in baseline facilitates high-fidelity 3D reconstruction previously unattainable with standard laparoscopic tools. In this paper, we present the system architecture of Sarascope 2.0, the calibration methodology developed and experimental results validating the quality of the resulting dense 3D point clouds and reconstruction.