MRI-compatible manipulator with remote-center-of-motion control

Area of Science:

• Robotics
• Medical Imaging
• Surgical Technology

Background:

• MRI-guided therapy requires precise needle placement.
• Selecting optimal needle insertion paths is challenging and time-consuming.
• A remote center of motion (RCM) is crucial for accurate targeting.

Purpose of the Study:

• To develop and evaluate a needle-guiding manipulator for MRI-guided therapy.
• To enable physicians to freely select needle insertion paths.
• To maintain a remote center of motion (RCM) at the tumor site during procedures.

Main Methods:

• The manipulator features a 3-DOF base stage and a 2-DOF passive needle holder.
• Synergistic control maintains the virtual RCM at a preplanned target.
• Encoder outputs from the needle holder drive the base stage motors.

Main Results:

• The manipulator aids in finding optimal needle insertion paths for liver tumors.
• The virtual RCM accuracy was within 3.0 mm.
• Physicians located needle insertion paths faster using the manipulator (P=0.001).
• Total alignment time, including planning, was not significantly reduced.

Conclusions:

• The robotic manipulator shows potential for accurate, interactive needle path selection in MRI-guided liver ablation.
• It can improve the efficiency and precision of therapeutic interventions.
• Further refinement may address overall time reduction in clinical settings.