Krieger Axel, Song Sang-Eun, Cho Nathan B, Iordachita Iulian, Guion Peter, Fichtinger Gabor, Whitcomb Louis L
Department of Mechanical Engineering and the Laboratory for Computational Sensing and Robotics, Johns Hopkins University, Baltimore, Maryland, USA, and is presently with Sentinelle Medical Inc., Toronto, Canada.
IEEE ASME Trans Mechatron. 2012 Sep 12;18(1):273-284. doi: 10.1109/TMECH.2011.2163523. Epub 2011 Oct 17.
This paper reports the design, development, and magnetic resonance imaging (MRI) compatibility evaluation of an actuated transrectal prostate robot for MRI-guided needle intervention in the prostate. The robot performs actuated needle MRI-guidance with the goals of providing (i) MRI compatibility, (ii) MRI-guided needle placement with accuracy sufficient for targeting clinically significant prostate cancer foci, (iii) reducing interventional procedure times (thus increasing patient comfort and reducing opportunity for needle targeting error due to patient motion), (iv) enabling real-time MRI monitoring of interventional procedures, and (v) reducing the opportunities for error that arise in manually actuated needle placement. The design of the robot, employing piezo-ceramic-motor actuated needle guide positioning and manual needle insertion, is reported. Results of a MRI compatibility study show no reduction of MRI signal-to-noise-ratio (SNR) with the motors disabled. Enabling the motors reduces the SNR by 80% without RF shielding, but SNR is only reduced by 40% to 60% with RF shielding. The addition of radio-frequency shielding is shown to significantly reduce image SNR degradation caused by the presence of the robotic device. An accuracy study of MRI-guided biopsy needle placements in a prostate phantom is reported. The study shows an average in-plane targeting error of 2.4 mm with a maximum error of 3.7 mm. These data indicate the system's needle targeting accuracy is similar to that obtained with a previously reported manually actuated system, and is sufficient to reliably sample clinically significant prostate cancer foci under MRI-guidance.
本文报道了一种用于前列腺磁共振成像（MRI）引导下针干预的主动式经直肠前列腺机器人的设计、开发及MRI兼容性评估。该机器人进行主动式针MRI引导，目标是提供：（i）MRI兼容性；（ii）MRI引导下的针放置，其精度足以靶向临床上重要的前列腺癌病灶；（iii）减少介入手术时间（从而提高患者舒适度并减少因患者运动导致针靶向错误的机会）；（iv）实现介入手术的实时MRI监测；（v）减少手动针放置中出现错误的机会。报道了该机器人的设计，其采用压电陶瓷电机驱动的针引导定位和手动针插入。MRI兼容性研究结果表明，在电机禁用时MRI信噪比（SNR）没有降低。启用电机在没有射频屏蔽的情况下会使SNR降低80%，但在有射频屏蔽的情况下SNR仅降低40%至60%。结果表明，添加射频屏蔽可显著降低由机器人设备的存在导致的图像SNR退化。报道了在前列腺模型中进行MRI引导的活检针放置的精度研究。该研究显示平面内靶向平均误差为2.4毫米，最大误差为3.7毫米。这些数据表明该系统的针靶向精度与先前报道的手动驱动系统相似，并且足以在MRI引导下可靠地对临床上重要的前列腺癌病灶进行采样。
