Faculty Advisor

Cosme Furlong

Faculty Advisor

James Van de Ven

Faculty Advisor

John Sullivan

Faculty Advisor

Gregory Fischer


"This thesis presents the development of a magnetic resonance imaging (MRI) compatible pneumatic actuation test system regulated by piezoelectric valve for image guided robotic intervention. After comparing pneumatic, hydraulic and piezoelectric MRI-compatible actuation technologies, I present a piezoelectric valve regulated pneumatic actuation system consisted of PC, custom servo board driver, piezoelectric valves, sensors and pneumatic cylinder. This system was proposed to investigate the control schemes of a modular actuator, which provides fully MRI-compatible actuation; the initial goal is to control our MRI-compatible prostate biopsy robot, but the controller and system architecture are suited to a wide range of image guided surgical application. I present the mathematical modeling of the pressure regulating valve with time delay and the pneumatic cylinder. Three different sliding mode control (SMC) schemes are proposed to compare the system performance. Simulation results are presented to validate the control algorithm. Practical tests with parameters determined from simulation show that the system performance attained the goal. A novel MRI- compatible locking device for the pneumatic actuator was developed to provide safe lock function as the pneumatic actuator fully stopped."


Worcester Polytechnic Institute

Degree Name



Mechanical Engineering

Project Type


Date Accepted





MRI-compatible robot, pneumatic actuator, sliding mode control, MRI-compatible lock