Robotic System With Stewart Platform and RCM Mechanism for Enhanced Precision and Safety in Non-Invasive Brain Stimulation.

Robotic technology has emerged as a promising solution for non-invasive brain stimulation (NIBS), which demands precise and repetitive stimulator movements. Conventional NIBS robots predominantly employ commercial robot arms with serial-link configurations, exhibiting precision and safety constraints. These arms have high end-effector inertia, making them suboptimal for compensating against unintended patient movements, such as respiration. Furthermore, the serial-link structure has a restricted workspace to access the hemispherical head geometry, posing potential collision risks between the robot and patient. This study proposes a robotic system integrating a Stewart platform and remote center of motion (RCM) mechanism to enhance accuracy and safety in NIBS applications. The low moment of inertia in parallel robots ensures precise and safe movements. Custom-designed RCM mechanism-based joints, optimized for NIBS, ensure comprehensive brain region coverage while minimizing collision risks. Furthermore, the robot incorporates an image-guided navigation system with a multi-stage control algorithm, optimizing patient comfort and procedural efficiency. Experimental validation, including NIBS tests on a customized phantom, demonstrates the system's feasibility. This paper presents the first successful implementation of a Stewart platform and RCM mechanism-based robot for NIBS, significantly advancing the field in terms of accuracy and safety.