3D Robotic Ultrasound System

Abstract

Diagnostic imaging is a fundamental requirement for the effective treatment of about 25 % of patients globally. Ultrasound imaging is considered the safest, least expensive and most convenient diagnostic imaging modality. Its widespread adoption has been in the area of 2D imaging. However, the accuracy of diagnosis with 2D ultrasound imaging is highly dependent on the experience and expertise of the sonographer because the sonographer has to mentally create a 3D impression from multiple 2D images of the region of interest and this could lead to erroneous diagnosis. 3D ultrasound imaging addresses this concern, however, it drives up the cost of ultrasound imaging. Also, disadvantages such as difficulty in taking quality images, prolonged time in learning how to effectively take these images and human distress during the acquisition of these images have been reported. By leveraging the high level of precision, accuracy and maneuverability provided by robotic systems in conjunction with low-end ultrasound imaging platforms, 3D ultrasound images can be captured, the problem of human distress alleviated and subsequently reducing the cost of 3D ultrasound imaging. This project sought to explore the feasibility of designing a low-cost 3D ultrasound robotic system. The design followed a distributed system approach using ROS (Robotic Operating System) where the data acquisition decoupled from the processing and visualization unit. The performance of the design was tested by constructing 3D ultrasound images of custom made phantoms. These results were compared with 3D ultrasound images of the phantoms acquired using the Philips EPIQ 7 - a high-tier ultrasound machine. The results obtained with this design had a low resolution in comparison with those obtained with the Philips EPIQ 7 however, a 3D point cloud representation of the object embedded in the phantom can be seen. Also, a full 3D image of the phantom could not be acquired due the transducer movement limitations of the design. This design successfully demonstrates the feasibility of integrating low-end electronics with robotic systems to acquire 3D ultrasound images.