Development of an MRI-Compatible, Compact, Rotary-Linear Piezoworm Actuator

Abstract

A piezoelectric actuator was developed to operate safely deep inside the magnetic resonance imaging (MRI) machine bore. It is based on novel design that produces linear and rotary motion simultaneously increasing the accuracy of medical needle insertion procedures. The actuation method is based on the piezoworm principle, minimizing the actuator size, maximizing output force, and permitting micrometer scale insertion accuracy. Beryllium copper with high stiffness and strength was used in constructing the actuator to minimize image distortion and to achieve the targeted performance. Performance tests were performed by controlling the frequency input and observing the effect on speed, force and torque. The device achieved a linear speed of 5.4 mm/s and a rotary speed of 10.5 rpm.