Body-mounted MR-conditional Robot for Minimally Invasive Liver Intervention

TL;DR

This paper introduces a compact, body-mounted MR-conditional robot designed for precise needle guidance during MR-guided microwave ablation of liver tumors, improving workflow speed and accuracy.

Contribution

The paper presents a novel MR-conditional robotic platform with pneumatic actuation and optical control, optimized for use inside MR scanners for minimally invasive liver interventions.

Findings

Robot-assisted needle insertion error of 2.6±1.3 mm

Successful MR-conditionality verified in phantom studies

System shows promise for improved needle placement accuracy

Abstract

MR-guided microwave ablation (MWA) has proven effective in treating hepatocellular carcinoma (HCC) with small-sized tumors, but the state-of-the-art technique suffers from sub-optimal workflow due to speed and accuracy of needle placement. This paper presents a compact body-mounted MR-conditional robot that can operate in closed-bore MR scanners for accurate needle guidance. The robotic platform consists of two stacked Cartesian XY stages, each with two degrees of freedom, that facilitate needle guidance. The robot is actuated using 3D-printed pneumatic turbines with MR-conditional bevel gear transmission systems. Pneumatic valves and control mechatronics are located inside the MRI control room and are connected to the robot with pneumatic transmission lines and optical fibers. Free space experiments indicated robot-assisted needle insertion error of 2.6$\pm$1.3 mm at an insertion depth of 80 mm. The MR-guided phantom studies were conducted to verify the MR-conditionality and targeting performance of the robot. Future work will focus on the system optimization and validations in animal trials.