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arXiv · 2607.21918

Action-Conditioned World Model for Goal Plane Probe Guidance in Robotic Ultrasound

Siqi Fan·Mingcong Chen·Ran Liu·Zixuan Yang·Xiaoyu Fu·Xiaoqing Gao·Yunhui Liu·Hongbin Liu
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Abstract

We present an action-conditioned world model framework for goal plane probe guidance in robotic ultrasound, with a focus on neck ultrasound scanning. Autonomous ultrasound tasks often require large numbers of probe-motion trajectories for training, but collecting high-quality demonstrations is labor-intensive and explicit simulators are difficult to build because ultrasound appearance depends on contact, tissue deformation, and view-dependent acoustic artifacts. We address this problem with a two-stage model-based learning pipeline. First, a latent conditional diffusion world model predicts future ultrasound observations from recent context frames, probe motions and temporal offset. Second, a goal-conditioned temporal transformer predicts ordered probe motions and is fine-tuned using rewards from the frozen world model. Experiments on the self-collected dataset show that the world model preserves action-dependent anatomical structure on target-directed scans. In real-world closed loop experiments, the framework achieves success rates of 70.0\% for carotid guidance and 65.0\% for thyroid guidance. These results demonstrate the potential of learned ultrasound dynamics for training goal-directed robotic probe navigation.

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Siqi Fan, Mingcong Chen, Ran Liu, Zixuan Yang, Xiaoyu Fu, Xiaoqing Gao, Yunhui Liu, Hongbin Liu. 2026-07-24. Action-Conditioned World Model for Goal Plane Probe Guidance in Robotic Ultrasound. https://arxiv.org/abs/2607.21918

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