An MR-conditional high-torque pneumatic stepper motor for MRI-guided and robot-assisted intervention
Yue Chen1, Ka-Wai Kwok, Zion Tsz Ho Tse
1College of Engineering, The University of Georgia, Athens, GA, USA.
Annals of Biomedical Engineering
|June 25, 2014
Summary
This study introduces a novel MR-conditional pneumatic stepper motor for precise actuation in MRI environments. The motor achieves high torque with minimal impact on image quality, enabling advanced image-guided surgery.
Area of Science:
- Engineering
- Medical Imaging
- Robotics
Background:
- Magnetic resonance imaging (MRI) enables detailed soft tissue visualization.
- MR-conditional actuators are crucial for developing image-guided and robot-assisted surgical devices used during MRI.
- Existing actuators may interfere with MR image quality.
Purpose of the Study:
- To present a simple design for an MR-conditional stepper motor.
- To achieve precise, high-torque actuation without degrading MR image quality.
- To establish a standard for evaluating pneumatic motors for MRI applications.
Main Methods:
- Designed an MR-conditional stepper motor using two pneumatic cylinders and a planetary gearbox.
- Tested the motor's dynamics performance, including output torque and accuracy.
- Evaluated MRI compliance by testing in 3T MRI scanners and assessing image artifacts and signal-to-noise ratio (SNR).
Main Results:
- Achieved a maximum output torque of 800 mN·m.
- The motor demonstrated minimal impact on MR image quality, with only a 2.35% SNR reduction and no observable artifacts beyond the motor body.
- The motor's accuracy was investigated in relation to operating speed and step size.
Conclusions:
- The developed pneumatic stepper motor is MR-conditional and suitable for precise actuation in MRI environments.
- The motor design offers high torque and minimal interference with MR imaging.
- The study provides a validated method for assessing the MRI compatibility of pneumatic motors for future integration into motorized devices.
