Prostate Targeting: Compact Robot With Harmonic Stepper Motors for MRI-Guided Needle Therapy

Area of Science:

• Robotics
• Medical Imaging
• Biomedical Engineering

Background:

• Magnetic Resonance Imaging (MRI) offers superior image quality and contrast, ideal for soft tissue tumor targeting in interventional procedures.
• Existing robotic systems for MRI-guided interventions face challenges with compatibility and precision.

Purpose of the Study:

• To present an innovative, MR-compatible robotic system for precise tumor targeting using MRI.
• To introduce novel Harmonic Pneumatic Motors for driving the robotic system within the MR environment.

Main Methods:

• Development of a four degrees of freedom (DOFs) robot utilizing four Harmonic Pneumatic Motors.
• The Harmonic Pneumatic Motor employs a harmonic gearbox mechanism for torque generation.
• Integration of a dual-stage needle guide for enhanced targeting accuracy.

Main Results:

• The Harmonic Pneumatic Motor achieves a step size of 0.9° and a maximum output torque of 825 mN·m.
• Experimental tests confirmed a high robot positioning accuracy of 1.56 mm.
• MR testing showed negligible signal-to-noise ratio (SNR) reduction, indicating excellent MR compatibility.

Conclusions:

• The Harmonic Pneumatic Motor-Driven Robot offers a significant advancement for compact MRI robots.
• The system provides a precise, safe, and compatible solution for MRI-guided interventional procedures.