A Track-based Colon Endoscopic Robot with Depth Perception Stereo Cameras for Haustral Fold Detection during Colonic Navigation

Colon endoscopic robots represent a promising screening modality for the visualization of colon cancers with high sensitivity. However, current colonoscopy robots are often characterized by intricate and bulky mechanical structures, which pose practical challenges when moving through the complex and narrow environment of the colon. Moreover, these robots are typically equipped with a single camera, limiting their ability to accurately estimate the depth of haustral folds in the colon, which is of great importance for the active colonic navigation of the robots. To address these challenges, we develop a track-based stereoscopic endoscopic robot (TSER) which is equipped with four tracks positioned at the corners of its body. This innovative design maximizes the contact between the tracks and the colon wall, enhancing maneuverability. The tracks are constructed from de-molded polydimethylsiloxane (PDMS) and incorporate micro-patterns on their outer surfaces. We have proposed a straightforward strategy for detecting haustral folds using TSER’s stereo camera, which allows for precise identification of their position and depth. The TSER achieves an average motion speed of 9.8 mm/s in a bellows tube that contains silicone oil and a speed of 5.2 mm/s in an exvivo porcine intestinal segment. Impressively, the TSER boasts an 88.11% accuracy rate in haustral fold depth estimation, surpassing the performance of existing geometric shape fitting methods. These results demonstrate that the TSER holds great potential for effective and efficient movement and inspection within the colon, offering a promising solution for improved colon cancer screening.