Development of a Robotic Carotid Blood Flow Measurement System-Automated Positioning and Visual Servoing of the Ultrasound Probe by Ultrasound Image Feedback-

Abstract

One of the important tasks required for sonographers is an accurate positioning of ultrasound probe. Especially, the measurement of the diameter of the blood vessel is affected by the positioning error of the probe. For this purpose, we have been developing a robot system for the medical ultrasound diagnosis, which composed of a 6-DOFs probe manipulator and supporting arm. In this paper, we present an implementation of fully automated positioning algorithm of the ultrasound probe on the carotid artery, by means of image feedback. A probe holding robot firstly detects the patient skin, then scans and detects the longitudinal section of the carotid artery, guide the probe towards the position where the tissue layers of the artery walls are most clearly observed. Furthermore, a new method of the visual servoing for tracking the out-of-plane motion for the medical ultrasound is presented. Automated positioning algorithm is tested in eleven volunteers and the results show that the system successfully completed the task in 91% of the trials. Visual servoing algorithm is also tested and the experimental results show its effectiveness.