Robotic Arm Based Automatic Ultrasound Scanning for Three-Dimensional Imaging

This paper presents a human skin inspired automatic robotic ultrasound (US) system for three-dimensional (3-D) imaging. A depth camera was adopted to capture the point cloud of the skin surface. According to the 3-D contour of the skin surface, the scan range and scan path for the US probe could be automatically determined. Then, we used a normal-vector-based method to determine the pose of the robotic arm corresponding to each scan point in the scan path. In addition, two force sensors could feedback the contact force between the scanned tissue and the emission plane of the probe for fine-tuning the pose of the robotic arm. After the scanning, the system could realize 3-D US reconstruction. Experimental results validate the feasibility of the proposed system. It is expected that the proposed system will be useful in clinical practices.

I. Introduction

As an indispensable diagnosis-aid technology, ultrasound (US) examination is of increasing importance in recent years [1]. It provides the B-scan with low cost and no radiation in real time [2]. The use of US would even increase in daily medicine and healthcare routines in the future. Traditional two-dimensional (2-D) US can dynamically display 2-D images of the region of interest [3]. However, the lack of 3-D anatomy information makes the diagnosis result heavily dependent on the subjective experience of the doctor. The 3-D US can overcome this serious limitation [4]–[9]. 3-D US imaging can be realized with three main steps: first, collect the raw B-scans labeled with corresponding spatial information; second, reconstruct the 3-D volume; and finally, render and display the 3-D volume. Every step has a significant influence on the accuracy of 3-D imaging. Except for systems using 2-D arrays, 3-D US images are reconstructed from raw B-scans, with their respective spatial information. Therefore, the scanning manners (especially the skills for manipulating the probe) and precise recording of position and orientation of B-scans are very important to ensure correct 3-D reconstruction. Only based on accurate 3-D US imaging data, 3-D image analysis [10], [11] can be further realized.