Fig. 1. Trocar-camera assembly^[26]

Fig. 2. Dual-view capsule endoscope^[30]

Fig. 3. Design scheme of compact dual-view endoscope^[33]

Fig. 4. Design scheme of freeform surface lens^[33]

Fig. 5. Principle schematic diagram of panoramic annular lens

Fig. 6. Endoscope system based on PAL and freeform surface lens^[34]

Fig. 7. Design of foveated wide angle endoscope lens^[36]

Fig. 8. Design of endoscope based on convex parabolic mirrors^[38]

Fig. 9. Prototype of bionic endoscope based on compound lens^[39]

Fig. 10. Schematic diagram of compact dual-view endoscope design^[41]

Fig. 11. Disparity results of real endoscopic images. (a) Input image (left); (b) disparity map produced by the SGBM algorithm; (c) disparity map produced by StereoNet

Fig. 12. Reconstruction 3D point cloud of the whole stomach^[60]

Fig. 13. Experiment scene and full-view 3D point clouds

Fig. 14. Framework for monocular SLAM-endoscopy^[70]

Fig. 15. 3D point cloud reconstructed by SfM^[71]

Fig. 16. (a) Schematic diagram of CapsoCam SV1 capsule endoscope and (b) image captured by SV1

Fig. 17. Typical signs of mucosal atrophy detected by panoramic capsule endoscope^[8]

Fig. 18. Images captured by traditional colonoscopy and FUSE^[73]

Fig. 19. (a) FUSE colonoscope; (b) image captured by FUSE