“Interactive multi-stage robotic positioner for intra-operative MRI-guided stereotactic neurosurgery”, a paper in Advanced Science

Feb 23, 2024

Professor Ka-Wai Kwok of the Department of Mechanical Engineering and his team worked on the research for the topic “Interactive Multi-Stage Robotic Positioner for Intra-Operative MRI-Guided Stereotactic Neurosurgery”. The research findings were recently published in Advanced Science on December 10, 2023.

Details of the publication:

Interactive Multi-Stage Robotic Positioner for Intra-Operative MRI-Guided Stereotactic Neurosurgery

Zhuoliang He, Jing Dai, Justin Di-Lang Ho, Hon-Sing Tong, Xiaomei Wang, Ge Fang, Liyuan Liang, Chim-Lee Cheung, Ziyan Guo, Hing-Chiu Chang, Iulian Iordachita, Russell H. Taylor, Wai-Sang Poon, Danny Tat-Ming Chan, Ka-Wai Kwok, article in Advanced Science


Magnetic resonance imaging (MRI) demonstrates clear advantages over other imaging modalities in neurosurgery with its ability to delineate critical neurovascular structures and cancerous tissue in high-resolution 3D anatomical roadmaps. However, its application has been limited to interventions performed based on static pre/post-operative imaging, where errors accrue from stereotactic frame setup, image registration, and brain shift. To leverage the powerful intra-operative functions of MRI, e.g., instrument tracking, monitoring of physiological changes and tissue temperature in MRI-guided bilateral stereotactic neurosurgery, a multi-stage robotic positioner is proposed. The system positions cannula/needle instruments using a lightweight (203 g) and compact (Ø97 × 81 mm) skull-mounted structure that fits within most standard imaging head coils. With optimized design in soft robotics, the system operates in two stages: i) manual coarse adjustment performed interactively by the surgeon (workspace of ±30°), ii) automatic fine adjustment with precise (<0.2° orientation error), responsive (1.4 Hz bandwidth), and high-resolution (0.058°) soft robotic positioning. Orientation locking provides sufficient transmission stiffness (4.07 N/mm) for instrument advancement. The system's clinical workflow and accuracy is validated with lab-based (<0.8 mm) and MRI-based testing on skull phantoms (<1.7 mm) and a cadaver subject (<2.2 mm). Custom-made wireless omni-directional tracking markers facilitated robot registration under MRI.