Development of Multi-DOF Ultrasonic Actuators for Surgical Tools

Abstract

Over the past decade, robotic technology has been rapidly gaining acceptance in the operation room. In robotic surgery, compact manipulators with multi-degree-of-freedom (DOF) are essential owing to a small work volume in the patient body. To generate multi-DOF motion, single DOF actuators such as electromagnetic motors have been conventionally used. That, however, requires multiple actuators, which in turn results in bulky mechanism combined with reduction device. In recent years, various compact multi-DOF actuators have been proposed and developed. Among them ultrasonic motors have become popular due to its simple structure and high torque capacity. Our previous work developed an ultrasonic motor capable of generating a multi-DOF rotation of a spherical rotor using three natural vibration modes of a bar-shaped stator. This study develops a novel multi-DOF master-slave system for surgical procedures using the single ultrasonic motor. The system consists of surgical forceps on multi-DOF wrist with joystick controller. Experiments have confirmed high responsiveness of the master-slave system with real-time position control scheme.