AMNCutter: Affinity-Attention-Guided Multi-View Normalized Cutter for Unsupervised Surgical Instrument Segmentation

Mingyu Sheng, Jianan Fan, Dongnan Liu, Ron Kikinis, Weidong Cai; Proceedings of the Winter Conference on Applications of Computer Vision (WACV), 2025, pp. 4533-4544

Surgical instrument segmentation (SIS) is pivotal for robotic-assisted minimally invasive surgery assisting surgeons by identifying surgical instruments in endoscopic video frames. Recent unsupervised surgical instrument segmentation (USIS) methods primarily rely on pseudo-labels derived from low-level features such as color and optical flow but these methods show limited effectiveness and generalizability in complex and unseen endoscopic scenarios. In this work we propose a label-free unsupervised model featuring a novel module named Multi-View Normalized Cutter (m-NCutter). Different from previous USIS works our model is trained using a graph-cutting loss function that leverages patch affinities for supervision eliminating the need for pseudo-labels. The framework adaptively determines which affinities from which levels should be prioritized. Therefore the low- and high-level features and their affinities are effectively integrated to train a label-free unsupervised model showing superior effectiveness and generalization ability. We conduct comprehensive experiments across multiple SIS datasets to validate our approach's state-of-the-art (SOTA) performance robustness and exceptional potential as a pre-trained model. Our code is released at https://github.com/MingyuShengSMY/AMNCutter.