Reeling It In: Flexible Needle Pick Up via Thread Manipulation for Autonomous Suturing

2026-07-28

AI Summary

In autonomous surgical suturing, the suture needle is often difficult to grasp safely due to occlusion, inaccessibility, or its placement on tissue, leading to potential tissue damage or needle slippage. This work proposes a novel indirect needle grasping framework based on suture manipulation, which leverages the suture thread itself as an auxiliary tool. By integrating vision-guided tissue-suture reconstruction, uncertainty-aware grasp point selection, stable thread lifting, and bimanual coordinated thread-following maneuvers, the method enables robust needle acquisition while minimizing unnecessary instrument-tissue contact. The approach demonstrates reliable performance even in complex or occluded scenarios. Experimental validation on the da Vinci Research Kit confirms its robustness across diverse real-world settings, successfully accomplishing needle retrieval despite challenging thread configurations or hard-to-reach needle positions.

Abstract

Suture-needle pickup is necessary for autonomous suturing, as a needle can be unexpectedly dropped or strategically released to adjust the grasping configuration. Current methods for autonomous needle pickup typically guide a robot to move straight toward the needle and grasp it, limited to conditions where the needle is observable and directly approachable. In addition, grasping the needle lying on tissue can lead to the robot pinching nearby tissue or the needle jumping around due to its slippery surface, posing potential safety issues. This work proposes an autonomous framework that uses a suture thread as an assistive tool for indirect needle pickup, avoiding unnecessary tool-tissue contact and enabling pickup even when the needle is occluded or inaccessible. The framework spans the entire workflow, including thread and tissue reconstruction, safe grasp-point selection, stable thread lifting, and bimanual thread-following until securing needle grasping. The robot policies account for visual uncertainty to maximize robustness in real-world environments. We evaluate the proposed framework on a da Vinci Research Kit under various real-world conditions. The results demonstrate robust performance even with a challenging thread configuration or a non-approachable needle, closing the gap in applying autonomous robot policies to unstructured suturing environments.

Problem

• autonomous suturing
• needle pickup
• thread manipulation
• occluded needle
• tissue safety

Innovation

• thread manipulation
• autonomous suturing
• indirect needle pickup
• bimanual robot control
• visual uncertainty