Towards Surgical World-Action Modeling: A Preliminary Joint Visual-Trajectory Forecasting for Surgical Motion Planning

Towards Surgical World-Action Modeling: A Preliminary Joint Visual-Trajectory Forecasting for Surgical Motion Planning

|Authors: Weiliang Huang, Huanrong Liu, Bob Zhang, Qi Dou, Zhen Chen, Yun Gu, Guy Rosman, Qingbiao Li

|Venue: arXiv preprint | Year: 2026

|arXiv: 2608.20284v1

Abstract

Reliable surgical planning requires models to anticipate not only how instruments will move, but also how the operative visual state will evolve together with such motion. Existing approaches typically treat future scene generation and instrument trajectory prediction as two separate tasks. Scene-only models cannot directly evaluate the accuracy of future instrument motion at the trajectory level, while trajectory-only models fail to capture the visual consequences of instrument movement, leaving the consistency between predicted trajectories and future scene evolution unaddressed. Jointly forecasting both provides a more complete account of surgical action-scene dynamics by enabling explicit trajectory-level evaluation while simultaneously modeling the corresponding visual evolution. To bridge this gap, we present a preliminary joint visual-trajectory world-action model that simultaneously forecasts future visual states and instrument trajectories from historical surgical observations. Specifically, we encode historical video frames and tool trajectories into latent representations, which are processed by a temporal-spatial encoder and subsequently decoded through separate visual-state and trajectory prediction heads. Based on this preliminary architecture, a chunked autoregressive rollout is repeatedly applied to predict fifteen future steps. The chunked strategy consistently outperforms direct one-shot prediction across all evaluated horizons, improving first-segment PSNR from 18.86 to 23.11 dB and reducing ADE from 45.77 to 22.22 pixels. These results demonstrate the initial feasibility of joint visual-motion forecasting. However, we observe progressive visual degradation and accumulated trajectory errors over longer prediction horizons, which remain important challenges for future surgical world-action modeling.

Key Contributions

• Reliable surgical planning requires models to anticipate not only how instruments will move, but …
• Existing approaches typically treat future scene generation and instrument trajectory prediction …
• Scene-only models cannot directly evaluate the accuracy of future instrument motion at the trajec…
• Jointly forecasting both provides a more complete account of surgical action-scene dynamics by en…
• To bridge this gap, we present a preliminary joint visual-trajectory world-action model that simu…

Topics

• vision
• reinforcement-learning
• planning
• benchmark

Code & Data

• GitHub repository: https://github.com/anonymous-authors-code/MICCAI2026_Workshop_

BibTeX

@article{Huang2026_260820284v1,
  title     = {Towards Surgical World-Action Modeling: A Preliminary Joint Visual-Trajectory Forecasting for Surgical Motion Planning},
  author    = {Weiliang Huang and Huanrong Liu and Bob Zhang and Qi Dou and Zhen Chen and Yun Gu and Guy Rosman and Qingbiao Li},
  year      = {2026},
  eprint    = {2608.20284v1},
  archivePrefix = {arXiv},
  primaryClass  = {cs.CV},
  url       = {https://arxiv.org/abs/2608.20284v1}
}