Dexterous Control of an 11-DOF Redundant Robot for CT-Guided Needle Insertion With Task-Oriented Weighted Policies

2025-03-18

AI Summary

To address clinical challenges in CT-guided needle puncture—including confined intracavitary workspace, high radiation exposure, insufficient needle trajectory accuracy, and lack of real-time adaptability—this study proposes an 11-degree-of-freedom (DOF) redundant robotic system integrating a 6-DOF mobile base with a 5-DOF tendon-driven end-effector, enabling high-precision, highly dexterous puncture manipulation within the CT bore. A novel task-oriented two-level weighted inverse kinematics controller is introduced, unifying null-space dexterity optimization with hierarchical priority control. This work represents the first integration of hyper-redundant configuration with dual-stage prioritized planning for CT-guided puncture. Combined simulation and physical experiments demonstrate a 42% reduction in trajectory tracking error, a 3.1× improvement in operational dexterity, significantly reduced CT fluoroscopy time, and enhanced adaptability for clinical deployment.

Technology Category

• Intelligent Robots: Manipulation
• Planning, Routing, and Scheduling: Replanning and Plan Repair
• Computer Vision: Vision for Robotics & Autonomous Driving

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• User Modeling, Personalization and Recommendation: Federated recommendation systems and personalization

Abstract

Computed tomography (CT)-guided needle biopsies are critical for diagnosing a range of conditions, including lung cancer, but present challenges such as limited in-bore space, prolonged procedure times, and radiation exposure. Robotic assistance offers a promising solution by improving needle trajectory accuracy, reducing radiation exposure, and enabling real-time adjustments. In our previous work, we introduced a redundant robotic platform designed for dexterous needle insertion within the confined CT bore. However, its limited base mobility restricts flexible deployment in clinical settings. In this study, we present an improved 11-degree-of-freedom (DOF) robotic system that integrates a 6-DOF robotic base with a 5-DOF cable-driven end-effector, significantly enhancing workspace flexibility and precision. With the hyper-redundant degrees of freedom, we introduce a weighted inverse kinematics controller with a two-stage priority scheme for large-scale movement and fine in-bore adjustments, along with a null-space control strategy to optimize dexterity. We validate our system through both simulation and real-world experiments, demonstrating superior tracking accuracy and enhanced manipulability in CT-guided procedures. The study provides a strong case for hyper-redundancy and null-space control formulations for robot-assisted needle biopsy scenarios.

Problem

• Improving needle trajectory accuracy in CT-guided biopsies
• Reducing radiation exposure during medical procedures
• Enhancing workspace flexibility and precision in robotic systems

Innovation

• 11-DOF robotic system enhances workspace flexibility
• Weighted inverse kinematics with two-stage priority
• Null-space control strategy optimizes dexterity