Hydrostatic Actuation for Remote Operations in MR Environment

This article presents a novel design and experiment of a system of hydrostatic actuation, transmission network, and control as a research platform for investigating magnetic resonance image (MRI) based tracking and intervention of a moving target. Based on novel double-acting piston-cylinder type rolling diaphragm fluid actuators, the system comprises two remotely controlled modules, an instrument manipulation module and a target motion module. The instrument manipulation module controls an instrument to access a target and it features a fluid network of multiple actuators and several modes of the instrument intervention of a stationary or moving target. The target motion module generates emulated target motions, such as breathing profiles, in the interventions. It also serves as truth motion for developing and testing MRI scanning and tracking algorithms. An iterative learning control is employed to create precise target motion profiles without needing real-time feedback from an MR-safe/conditional sensor. Integrating the two modules, the system enables closed-loop actuated intervention study with real-time MRI.