Fully Robotized 3D Ultrasound Image Acquisition for Artery

Current imaging of the artery relies primarily on computed tomography angiography (CTA), which requires contrast injections and exposure to radiation. In this paper, we present a method for fully autonomous artery 3D image acquisition using a linear ultrasound (US) probe and a 6 DoFs robot arm with a 3D camera. Robotic vessel acquisition can minimize tissue deformation and permit the reproduction of scans. Additionally, the robotic-based acquisition can provide more precise vessel position data that can be utilized for 3D reconstruction as a preoperative image. The first scanning point is determined by the 3D camera using a neural network for leg area estimation. A visual servo algorithm adjusts the in-plane motions using a cross-sectional vessel segmentation produced by a neural network with a UNet structure, while a US confidence map regulates the in-plane rotation. The robot is equipped with impedance control to maintain a constant and safe scan. Experiments on a leg phantom and a volunteer indicate that the robot can follow the vessel and modify its position to provide a sharper US image. The average error of phantom scanning in y-axis and z-axis are 0.2536mm and 0.2928mm, respectively, while the root means square error (RMSE) of contact force in the volunteer experiment is 0.2664N. In addition, a 3D vessel reconstruction demonstrates the possibility of robotic US acquisition as a preoperative image.

I. Introduction

The history of ultrasound (US) applications began 1826, when sound waves, known as sonar, were used to detect the distances underwater. In 1942, ultrasonic was initially used as a medical imaging technique in the United States [1]. Ultrasonography is an imaging technique that is non- invasive. Unlike computerized tomography (CT) scans, the patient was not exposed to ionising radiation. In contrast to magnetic resonance imaging (MRI), cardiac pacemakers and metal implants are risk-free for the patient. Ultrasound can detect, localize, and characterize the majority of soft tissue lesions effectively [2]–[4]. Besides locating the lesion and directing the treatment, ultrasonography is a valid imaging method in interventional radiology [5]. The application of ultrasound in the medical and surgical fields encompasses a variety of disciplines, including gynecology and obstetrics, urology, general surgery, and vascular and orthopaedic surgery.