2D Ultrasound-Guided Visual Servoing for In-Plane Needle Tracking in Robot-Assisted Percutaneous Nephrolithotomy

摘要

Ultrasound (US)-guided percutaneous nephrolithotomy is a surgical procedure for large kidney stone removal through an incision in the patient's back. To gain kidney access, the surgeon steers a needle towards the kidney while simultaneously controlling the position and orientation of a US probe to keep the needle in the image plane. To successfully reach the kidney while avoiding delicate structures, a significant level of skill and precision is required. To alleviate the surgeon's cognitive workload, robot-assisted needle tracking can be implemented to autonomously track the needle in the US images and adjust the US probe's position and orientation such that the same portion of the needle is visible in the images. This paper presents a US-guided visual servoing (VS) algorithm to track the translation and rotation of a needle in a plane. Image features representing the desired pose of the needle in the image are defined, through which an interaction matrix is devised to relate the rate of the change of the image features in US images to the required position and orientation of the US probe connected to a robotic manipulator. Experimental results in 4 experimental scenarios in a water tank demonstrate the capability of the proposed method in tracking the needle in real-time with an accuracy of 2.6 mm with a control rate of 20 Hz. Although VS has been used to track surgical targets in the past, this paper proposes the first implementation of VS for needle tracking in longitudinal US images subjected to 3-DOF motion in a plane without any prior knowledge of needle trajectory or additional position sensors.