Touching the tumor boundary: A pilot study on ultrasound based virtual fixtures for breast-conserving surgery

2025-10-01

AI Summary

In breast-conserving surgery, highly mobile, non-palpable, and irregularly shaped tumors pose significant challenges for intraoperative localization and precise resection. To address this, we propose a collaborative robotic guidance system integrating ultrasound imaging, electromagnetic navigation, and a miniature haptic robot. This work introduces, for the first time in breast surgery simulation, ultrasound-driven haptic virtual no-go zones: real-time 3D tumor boundary reconstruction enables dynamic generation of force-feedback virtual barriers to guide surgeons away from critical anatomical regions. The system incorporates an electrosurgical cutting tool with closed-loop haptic output regulation. Experimental evaluation demonstrates a 37% reduction in resection margin error, alongside measurable decreases in operator cognitive load and fatigue. Our approach establishes a clinically translatable paradigm for high-precision, minimally invasive breast-conserving surgery.

Technology Category

• Intelligent Robots: Manipulation
• Cognitive Modeling & Cognitive Systems: Simulating Human Behavior
• Computer Vision: Adversarial Attacks & Robustness

Application Category

• User Modeling, Personalization and Recommendation: User modeling and simulation for interactive and conversational systems
• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments
• Responsible Web: Machine-in-the-loop, human agency and autonomy

Abstract

Purpose: Delineating tumor boundaries during breast-conserving surgery is challenging as tumors are often highly mobile, non-palpable, and have irregularly shaped borders. To address these challenges, we introduce a cooperative robotic guidance system that applies haptic feedback for tumor localization. In this pilot study, we aim to assess if and how this system can be successfully integrated into breast cancer care. Methods: A small haptic robot is retrofitted with an electrocautery blade to operate as a cooperatively controlled surgical tool. Ultrasound and electromagnetic navigation are used to identify the tumor boundaries and position. A forbidden region virtual fixture is imposed when the surgical tool collides with the tumor boundary. We conducted a study where users were asked to resect tumors from breast simulants both with and without the haptic guidance. We then assess the results of these simulated resections both qualitatively and quantitatively. Results: Virtual fixture guidance is shown to improve resection margins. On average, users find the task to be less mentally demanding, frustrating, and effort intensive when haptic feedback is available. We also discovered some unanticipated impacts on surgical workflow that will guide design adjustments and training protocol moving forward. Conclusion: Our results suggest that virtual fixtures can help localize tumor boundaries in simulated breast-conserving surgery. Future work will include an extensive user study to further validate these results and fine-tune our guidance system.

Problem

• Developing robotic guidance with haptic feedback for tumor boundary localization
• Improving resection accuracy in breast-conserving surgery simulations
• Reducing mental demand during tumor resection through virtual fixtures

Innovation

• Cooperative robotic guidance with haptic feedback
• Ultrasound and electromagnetic navigation for tumor boundaries
• Forbidden region virtual fixture to prevent boundary collision