Simple methods to test the accuracy of MRgFUS robotic systems

Abstract

Background Robotic‐assisted diagnostic and therapeutic modalities require a highly accurate performance to be certified for clinical application. In this paper, three simple methods for assessing the accuracy of motion of magnetic resonance‐guided focused ultrasound (MRgFUS) robotic systems are presented. Methods The accuracy of motion of a 4 degrees of freedom robotic system intended for preclinical use of MRgFUS was evaluated by calliper‐based and magnetic resonance imaging (MRI) methods, as well as visually by performing multiple ablations on a plastic film. Results The benchtop results confirmed a highly accurate motion in all axes of operation. The spatial positioning errors estimated by MRI evaluation were defined by the size of the imaging pixels. Lesions arrangement in discrete and overlapping patterns confirmed satisfactory alignment of motion trajectories. Conclusions We believe the methods presented here should serve as a standard for evaluating the accuracy of motion of MRgFUS robotic systems.

Robotic device for transcranial focussed ultrasound applications in small animal models

“…The motion accuracy of both systems was assessed following a calliper‐based methodology as previously detailed in the literature 35 . The obtained results demonstrate that the motion error is decreasing with increasing motion step in all axes, with a maximum positioning error of about 0.1 mm for the 1‐mm step.…”

“…The accuracy and repeatability of robotic motion for the two versions of the robot was assessed following a calliper‐based method as previously detailed in the literature. 35 Briefly, motion steps of 1, 5, and 10 mm were commanded through the motion commands of the relevant software and compared with the actual displacements as measured with a high‐precision digital calliper. Additionally, the speed of motion in each axis was estimated by the activation time of the motion actuators, which is provided by the controlling software and equals to the time needed for the stage to cover the commanded step.…”

Robotic system for top to bottom MRgFUS therapy of multiple cancer types

“…A smooth and accurate rotation is established through a series of speed reduction gears that amplifies the motors' torque. It is noted that the robotic system has a motion accuracy level comparable to previous versions 21–23 since it follows a similar principle of motion, according to simple accuracy assessment methods 24 …”

“…It is noted that the robotic system has a motion accuracy level comparable to previous versions [21][22][23] since it follows a similar principle of motion, according to simple accuracy assessment methods. 24 ANTONIOU ET AL. space under the system for comfortable supine positioning of the patient.…”

Full coverage path planning algorithm for MRgFUS therapy

“…It is interesting to note that plastic films can be considered the cheapest phantom for quality assurance of hardware and software FUS systems. Notably, grid ablation on plastic films was previously proposed as a simple method to test the accuracy of robotic motion of FUS devices, 25 being beneficial over other proposed MRI‐based methods 26 in terms of cost‐effectiveness, ease of implementation, and accuracy.…”