Path Replanning for Orientation-Constrained Needle Steering.

Area of Science:

• Neurosurgery
• Robotics
• Medical Imaging

Background:

• Accurate catheter positioning is crucial for effective needle-based neurosurgical procedures.
• Challenges include tissue deformation, anatomical obstacles, and precise catheter control.

Purpose of the Study:

• To develop a novel path-replanning system for real-time, obstacle-free path generation during needle insertion.
• To enable precise guidance of a programmable bevel-tip needle (PBN) in a closed-loop system, accounting for anatomical changes.

Main Methods:

• A path-replanner combines 'Bubble Bending' for online path deformation and convex optimization for path smoothing.
• The system integrates electromagnetic sensor feedback for real-time needle tip tracking and guidance.
• Surgical constraints for avoiding sensitive structures are incorporated into the planning process.

Main Results:

• Simulations demonstrated an average targeting error of 0.65 ± 0.46 mm and 3.25 ± 5.23 degrees in a deformable environment.
• In-vitro tests on a gelatin phantom yielded an average error of 1.81 ± 0.51 mm and 5.9 ± 1.42 degrees.
• The PBN was guided with bounded curvature to the target pose, meeting surgical criteria.

Conclusions:

• The developed online steerable needle path-planner effectively avoids obstacles and optimizes surgical criteria.
• This method enhances accuracy in neurosurgical procedures involving tissue deformation and real-world inaccuracies.