Mechanical validation of an MRI compatible stereotactic neurosurgery robot in preparation for pre-clinical trials

Abstract

The use of magnetic resonance imaging (MRI) for guiding robotic surgical devices has shown great potential for performing precisely targeted and controlled interventions. To fully realize these benefits, devices must work safely within the tight confines of the MRI bore without negatively impacting image quality. Here we expand on previous work exploring MRI guided robots for neural interventions by presenting the mechanical design and assessment of a device for positioning, orienting, and inserting an interstitial ultrasound-based ablation probe. From our previous work we have added a 2 degree of freedom (DOF) needle driver for use with the aforementioned probe, revised the mechanical design to improve strength and function, and performed an evaluation of the mechanism’s accuracy and effect on MR image quality. The result of this work is a 7-DOF MRI robot capable of positioning a needle tip and orienting it’s axis with accuracy of 1.37 ± 0.06mm and 0.79° ± 0.41°, inserting it along it’s axis with an accuracy of 0.06 ± 0.07mm, and rotating it about it’s axis to an accuracy of 0.77° ± 1.31°. This was accomplished with no significant reduction in SNR caused by the robot’s presence in the MRI bore, ≤ 10.3% reduction in SNR from running the robot’s motors during a scan, and no visible paramagnetic artifacts.

Robotic Assisted MRI-Guided Interventional Interstitial MR-Guided Focused Ultrasound Ablation in a Swine Model

“…In an initial 3 animals, we optimized the workflow of the robot in the MR suite, and made modifications to the robotic arm to allow range of motion to reach the right and left frontal lobe and the cannula to penetrate the brain. 18 We optimized the use of Slicer software (3D Slicer, http://www.slicer.org) for neuronavigation use. 19 Accuracy during these experiments mirrored our phantom experience which showed a root mean square error 1.38 ± 0.45 mm in tip position and 2.03 ± 0.58 • in insertion angle.…”

Applications of high magnetic field in interventional medical treatment

“…由于磁共振系统有三轴梯度线圈, 这样就可以构造3个方向上的作动轴, 实现空间多自 由度的运动 [76,77] . 一个高自由度的作动器, 能够定位 插入, 并围绕轴旋转, 精度非常高, 且不会出现顺磁 伪影 [78] . 利用机械装置将转动转换为介入治疗系统 的 移 动 , 可 实 现 磁 共 振 系 统 控 制 的 手 术 过 程 [75~81] .…”

Magnetic resonance–guided interstitial high-intensity focused ultrasound for brain tumor ablation

“…2). 24 The robot is registered to the MRI scanner coordinate system with a fiducial frame attached to the bottom of the base platform, composed of 9 tubes filled with MRI-visible, high-contrast fluid and configured in a set of Z shapes similar to a standard Cosman-Roberts-Wells frame. 25 Localization of the robot with respect to the imaging system, and thus the animal, was accomplished by using multiple coronal images of the Z-shaped framework.…”