RobUSt–An Autonomous Robotic Ultrasound System for Medical Imaging

Abstract

Medical ultrasound (US) systems are widely used for the diagnosis of internal tissues. However, there are challenges associated with acquiring and interpreting US images, such as incorrect US probe placement and limited available spatial information. In this study, we expand the capabilities of medical US imaging using a robotic framework with a high level of autonomy. A 3D camera is used to capture the surface of an anthropomorphic phantom as a point cloud, which is then used for path planning and navigation of the US probe. Robotic positioning of the probe is realised using an impedance controller, which maintains stable contact with the surface during US scanning and compensates for uneven and moving surfaces. Robotic US positioning accuracy is measured to be 1.19±0.76mm. The mean force along US probe z-direction is measured to be 6.11±1.18N on static surfaces and 6.63±2.18N on moving surfaces. Overall lowest measured force of 1.58N demonstrates constant probe-to-surface contact during scanning. Acquired US images are used for the 3D reconstruction and multi-modal visualization of the surface and the inner anatomical structures of the phantom. Finally, K-means clustering is used to segment different tissues. Best segmentation accuracy of the jugular vein according to Jaccard similarity coefficient is measured to be 0.89. With such an accuracy, this system could substantially improve autonomous US acquisition and enhance the diagnostic confidence of clinicians.

Intravascular Tracking of Micro-Agents Using Medical Ultrasound: Towards Clinical Applications

“…These end-effector poses are generated based on the surface geometry captured using the 3D camera and the positions of the vessel centroids derived from intraoperative US scan by using the vessel segmentation algorithm described in section II.A. Surface scanning and the impedance control used for realizing the robot motion are both described in our prior work [35]. Path planning algorithm developed for this application is designed to calculate a surface path for acquiring US images containing consecutive centroids in sagittal crosssection of the vessel.…”

“…Based on this notion, a study by Zettinig et al [34] showed that US visual servoing can be used for neurosurgical navigation and needle guidance. Furthermore, in our previous studies, we have demonstrated both optical visual servoing [21] and impedance control [35] used for body motion compensation while performing robotic US scanning along the planned surface path.…”

Scanning Path Planning of the Robot for Breast Ultrasound Examination Based on Binocular Vision and NURBS

“…According to the average distance from point pi to the neighboring points, the point cloud noise is removed, as shown in Equation (12). 12), the points will be reserved, otherwise, the points will be removed.…”

“…Robots can assist doctors in completing breast ultrasound examinations, thus reducing the work intensity of doctors. Robots can accurately complete repetitive scanning operations to improve examination efficiency, standardize operation processes and reduce labor costs [10]- [12]. The robot for breast ultrasound examination requires high precision and efficiency to meet the scanning requirements.…”

A Fully Autonomous Robotic Ultrasound System for Thyroid Scanning

“…Most existing autonomous systems are still at level 2 [27][28][29][30], which rely on experts to design the acquisition procedure. Although some systems can reach level 3 (i.e., [31][32][33][34]), their clinical feasibility must be investigated further and compared with robotic assistant systems. To this end, fully autonomous robotic diagnosis is still challenging, as it calls for more perception, planning and control on the part of the robot.…”