Multi-Imager Compatible, MR Safe, Remote Center of Motion Needle-Guide Robot

Area of Science:

• Medical Robotics
• Image-Guided Interventions
• Biomedical Engineering

Background:

• Direct image-guided interventions (DIGI) require precise instrument manipulation.
• Existing robotic systems may face limitations in MRI environments due to electromagnetic interference.
• The development of MR-safe and accurate robotic manipulators is crucial for advancing minimally invasive procedures.

Purpose of the Study:

• To report the development of a novel robotic manipulator for direct image-guided interventions.
• To evaluate the system's safety, accuracy, and compatibility with MRI environments.
• To assess the manipulator's performance in preclinical tests for guiding slender instruments.

Main Methods:

• A new robotic manipulator was designed using pneumatic step motors and non-metallic materials.
• The manipulator features a two-degree-of-freedom (DoF) remote center of motion parallelogram mechanism for needle-guide orientation.
• A third remote DoF was incorporated for manual needle insertion depth control, alongside registration markers for image-to-robot alignment.

Main Results:

• The robotic system is MR safe (ASTM F2503-13) with minimal MRI signal-to-noise ratio change (<1%).
• Electromagnetic compatibility (EMC) testing confirmed no significant EM emissions.
• The manipulator demonstrated high structural stiffness (33 N/mm) and angular accuracy (0.177°).
• In vitro MRI-guided targeting accuracy and precision were 1.71 mm and 0.51 mm, respectively.

Conclusions:

• The developed robotic system is suitable for direct image-guided interventions requiring millimeter accuracy.
• Its MR safety, EMC compliance, and precise targeting capabilities make it a promising tool for various medical applications.
• The multi-imager compatibility allows for potential use with other imaging modalities, expanding its clinical utility.