Design, Modeling, and Experimental Characterization of a Fast Additively Manufacturable MRI-Compatible Pneumatic Motor for Surgical Robots

Abstract

For robot assisted surgery under magnetic resonance imaging (MRI) guidance, constraints such as material limits, actuation method limits and available sensor limits have made the design and control of an actuation and transmission system the most challenging problem.Aiming at tackling the aforementioned issues, this paper proposes a novel pneumatic powered motor, which features few as two inputs, continuous and back-drivable motion outputs, integrated MRI-compatible speed sensor, compact modularly switchable downspeed components, and fast additively manufacture ability (22 components in total).It promisingly fills the gap between the current MRI-compatible surgical robots and available actuation methods and offers an alternative approach for the community to actuate various surgical robotic platforms.Detailed design methods for the pneumatic motor and integrated rotary encoder are developed first.Motor performances are experimentally evaluated next to analyse and demonstrate its characteristics under various pressures against different load torques.Finally, the proposed pneumatic motor is compared with recent MRI-compatible pneumatic actuators, illustrating the feasibility of the proposed fluid power motor for actuations of MRI surgical robots.