Head-Mounted Hydraulic Needle Driver for Targeted Interventions in Neurosurger

Needle interventions are crucial in neurosurgery, requiring high precision and stability. This paper presents a 5-DoF head-mounted hydraulic needle robot designed for accurate and targeted needle insertion and neuroimaging in the deep brain. The robot is compact and lightweight by utilizing a hydraulic pipe transmission to connect the needle driver and actuator. The syringe pistons serve as the actuator and executor, enabling synchronized motion, minimal hysteresis, and high-accuracy insertion. The hydraulic transmission system exhibits hysteresis of less than 0.8 mm, with bidirectional insertion accuracy of approximately 0.05 mm. The resulting needle driver features a compact structure measuring 48 mm × 25 mm × 9 mm, accompanied by a 70-mm-long needle guide. The needle driver is mainly 3D printed, while the hydraulic transmission ensures full compatibility with magnetic resonance imaging (MRI) by isolating all electromagnetic parts from the executor. This compact and lightweight robot-assisted needle intervention system significantly enhances the safety, accuracy, and effectiveness of deep-brain neuroimaging. The feasibility of precise positioning and insertion is further demonstrated by deploying an optical coherence tomography (OCT) microneedle in a rat brain.