Abstract:Objective:To investigate the application effect of an artificial intelligence model based on the dual-branch semantic segmentation network (BiSeNet V2) in segmenting ultrasound images for anterior approach sciatic nerve blocks, and to provide an intelligent auxiliary method for nerve block localization.Methods:Prospectively, 100 patients undergoing ultrasound-guided anterior sciatic nerve blocks at the Second Clinical Medical College of Lanzhou University were enrolled from March to June 2025, yielding a total of 3000 ultrasound images. Two experienced anesthesiologists manually annotated the nerve regions using ITK-SNAP software. The collected data were randomly divided into training, validation, and test sets in a 6:2:2 ratio. A model based on the dual-branch BiSeNet V2 architecture was built and trained on the PyTorch platform. Evaluation metrics included the Mean Intersection over Union (mIoU), Mean Dice Coefficient (mDice), and overall accuracy.Results:The model achieved an mIoU of 0.671 and an mDice of 0.801 on the test set, with an overall accuracy of 98.7%. The median Intersection over Union (IoU) after 5-fold cross-validation was 0.973 (interquartile range), indicating stable model performance across different data splits.Conclusion:The ultrasound image segmentation model based on BiSeNet V2 can achieve high-precision identification of the sciatic nerve via the anterior approach while ensuring real-time segmentation speed, demonstrating good potential for clinical application.