School of Medicine. University of Dundee, Dundee, UK.
School of Medicine. University of Dundee, Dundee, UK.
Comput Methods Programs Biomed. 2017 Dec;152:125-130. doi: 10.1016/j.cmpb.2017.09.006. Epub 2017 Sep 20.
Magnetic Resonance Guided Focused Ultrasound (MRgFUS) for liver tumour ablation is a challenging task due to motion caused by breathing and occlusion due the ribcage between the transducer and the tumour. To overcome these challenges, a novel system for liver tumour ablation during free breathing has been designed.
The novel TRANS-FUSIMO Treatment System (TTS, EUFP7) interacts with a Magnetic Resonance (MR) scanner and a focused ultrasound transducer to sonicate to a moving target in liver. To meet the requirements of ISO 13485; a quality management system for medical device design, the system needs to be tested for certain process parameters. The duration of sonication and, the delay after the sonication button is activated, are among the parameters that need to be quantified for efficient and safe ablation of tumour tissue. A novel methodology is developed to quantify these process parameters. A computerised scope is programmed in LabVIEW to collect data via hydrophone; where the coordinates of fiber-optic sensor assembly was fed into the TRANS-FUSIMO treatment software via Magnetic Resonance Imaging (MRI) to sonicate to the tip of the sensor, which is synchronised with the clock of the scope, embedded in a degassed water tank via sensor assembly holder. The sonications were executed for 50 W, 100 W, 150 W for 10 s to quantify the actual sonication duration and the delay after the emergency stop by two independent operators for thirty times. The deviation of the system from the predefined specs was calculated. Student's-T test was used to investigate the user dependency.
The duration of sonication and the delay after the sonication were quantified successfully with the developed method. TTS can sonicate with a maximum deviation of 0.16 s (Std 0.32) from the planned duration and with a delay of 14 ms (Std 0.14) for the emergency stop. Student's T tests indicate that the results do not depend on operators (p > .05).
The evidence obtained via this protocol is crucial for translation- of-research into the clinics for safe application of MRgFUS. The developed protocol could be used for system maintenance in compliance with quality systems in clinics for daily quality assurance routines.
由于呼吸引起的运动和 transducer 与肿瘤之间的肋骨引起的阻塞，磁共振引导的聚焦超声（MRgFUS）用于肝脏肿瘤消融是一项具有挑战性的任务。为了克服这些挑战，设计了一种用于在自由呼吸期间进行肝脏肿瘤消融的新型系统。
新型 TRANS-FUSIMO 治疗系统（TTS，EUFP7）与磁共振（MR）扫描仪和聚焦超声 transducer 相互作用，以在肝脏中对移动目标进行超声治疗。为了满足医疗器械设计的 ISO 13485 要求；需要对系统进行某些过程参数的测试。需要对超声治疗的持续时间以及超声治疗按钮激活后的延迟进行量化，以实现肿瘤组织的高效和安全消融。开发了一种新的方法来量化这些过程参数。在 LabVIEW 中编写了一个计算机化的示波器，通过水听器收集数据；光纤传感器组件的坐标通过磁共振成像（MRI）输入到 TRANS-FUSIMO 治疗软件中，以将传感器的尖端超声治疗，与示波器的时钟同步，通过传感器组件支架嵌入脱气水箱中。对于 50W、100W 和 150W 的功率，执行了 10 秒的超声治疗，以量化由两名独立操作人员执行的实际超声治疗持续时间和紧急停止后的延迟三十次。计算了系统与预定义规格的偏差。使用学生 T 检验来研究用户依赖性。
成功使用开发的方法量化了超声治疗的持续时间和超声治疗后的延迟。TTS 可以以与计划持续时间相差 0.16 秒（标准偏差 0.32）的最大偏差进行超声治疗，并在紧急停止时延迟 14 毫秒（标准偏差 0.14）。学生 T 检验表明，结果不依赖于操作人员（p>.05）。
通过该方案获得的证据对于将研究转化为临床应用至关重要，以确保 MRgFUS 的安全应用。开发的方案可用于符合临床质量体系的系统维护，以进行日常质量保证常规。
