MAF-Net: A multi-scale attention fusion network for automatic surgical instrument segmentation

Abstract

Accurate localization of surgical instruments is of utmost importance for precise robot-assisted surgeries. With the development of artificial intelligence, deep convolutional neural networks (DCNNs) have been widely employed for automatic image segmentation, owing to their strong ability to generate contextual features, especially in the encoder–decoder framework. However, existing segmentation networks lack the feature capturing capability on micro objects and have shortcomings in processing local semantic features. These limitations can affect the precise segmentation of surgical instruments. In response to these issues, this paper proposes a multi-scale attention fusion network called MAF-Net, which comprises residual dense module, a multi-scale atrous convolution (MSAC) module, and an attention fusion module (AFM). To improve the processing ability of local contextual features, we propose replacing skip connections with residual dense module to acquire stronger contexts. Furthermore, a MSAC module is proposed for local feature enhancement, thereby enhancing attention on multi-scale features. In addition, an AFM module is introduced to integrate multi-scale information by cross-scale feature fusion. Experimental results, using two public datasets, Endovis2017 and kvasir-instrument, demonstrate that the proposed network has the ability to achieve precise surgical instrument segmentation and outperforms related advanced methods.