Endoscopic Landmark Detection

CNN-based endoscopic image analysis for autonomous GI robot navigation

During my undergraduate studies, I contributed to a medical robotics research project on automatic anatomical landmark detection in endoscopic images. The project aimed to support autonomous navigation of gastrointestinal robots by detecting the natural anatomical centre of the pylorus, the opening between the stomach and the duodenum.

This project was later published as: Su, B., Gong, Y., Chen, Y. et al. Detection of Healthy and Diseased Pylorus Natural Anatomical Center with Convolutional Neural Network Classification and Filters. J. Med. Biol. Eng. 42, 216–224 (2022). doi.org/10.1007/s40846-022-00696-6

Project background

For a gastrointestinal robot to move autonomously from the stomach into the duodenum, it needs to recognise the pylorus and identify a safe passage point. The pyloric centre is an important target because it provides a natural anatomical reference for guiding robot movement while reducing potential soft-tissue injury.

However, endoscopic images are visually complex. The appearance of the pylorus can vary between healthy and diseased cases, and the target structure may change shape, contrast, and orientation. This project therefore explored whether computer vision methods could automatically detect the pylorus centre from endoscopic images.

What we developed

The method combined convolutional neural network classification with classical image-processing filters, including Sobel and Laplace operators. The CNN component was used to classify image regions, while the filtering steps helped refine anatomical boundaries and estimate the pylorus centre.

The algorithm was evaluated across healthy and diseased pylorus images, including multiple anatomical appearances and pathological settings.

CNN
Image classification for pylorus localisation
Filters
Sobel and Laplace operators for boundary refinement
Real-time
Designed for fast anatomical centre tracking

Main results

The published study reported an average pylorus-centre detection error of 22.33 pixels, corresponding to a 2.33% relative error against the 960-pixel diagonal length of the endoscopic image. The average processing time was 26.51 ms per image, supporting the feasibility of real-time tracking.

22.33 px
Average centre-detection error
2.33%
Relative error against image diagonal length
26.51 ms
Average processing time per image