Development of a Parallel-Mechanism-Based Robotic Wrist With Remote Center of Motion Capability to Assist Ultrasound Scanning

In recent years, the combination of ultrasound imaging and robotics has opened up new possibilities, and a flexible and efficient robotic wrist is the key to achieving the implementation of this technology. Equipped with an ultrasound probe, a robotic wrist with remote center of motion (RCM) control can effectively assist physicians in performing ultrasound examinations. In this paper, we present the development of a parallel mechanism-based robotic wrist and illustrate the kinematic solution of the control, which can effectively set different RCM points. For validation, we tested the control accuracy of the prototype using an optical tracking system and the results show that the average absolute translational error is 0.51mm, rotational error is 0.41° and the constraint point error along the axis is 0.57mm. Furthermore, to simulate a realistic environment, an ultrasound image acquisition experiment is designed based on an ultrasound abdominal phantom. The results effectively demonstrate the effectiveness of RCM control for adjusting actual ultrasound images through real image acquisition, demonstrating the usefulness of the method in assisting physicians to perform ultrasound sweeps as well as providing new ways of acquiring diagnostic information.