Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.
Government Associate Laboratory, ICVS/3B's-PT, Braga/Guimarães, Portugal.
Med Phys. 2020 Jan;47(1):19-26. doi: 10.1002/mp.13879. Epub 2019 Nov 22.
Electromagnetic tracking systems (EMTSs) have been proposed to assist the percutaneous renal access (PRA) during minimally invasive interventions to the renal system. However, the influence of other surgical instruments widely used during PRA (like ureteroscopy and ultrasound equipment) in the EMTS performance is not completely known. This work performs this assessment for two EMTSs [Aurora Planar Field Generator (PFG); Aurora Tabletop Field Generator (TTFG)].
An assessment platform, composed by a scaffold with specific supports to attach the surgical instruments and a plate phantom with multiple levels to precisely translate or rotate the surgical instruments, was developed. The median accuracy and precision in terms of position and orientation were estimated for the PFG and TTFG in a surgical environment using this platform. Then, the influence of different surgical instruments (alone or together), namely analogic flexible ureterorenoscope (AUR), digital flexible ureterorenoscope (DUR), two-dimensional (2D) ultrasound (US) probe, and four-dimensional (4D) mechanical US probe, was assessed for both EMTSs by coupling the instruments to 5-DOF and 6-DOF sensors.
Overall, the median positional and orientation accuracies in the surgical environment were 0.85 mm and 0.42° for PFG, and 0.72 mm and 0.39° for TTFG, while precisions were 0.10 mm and 0.03° for PFG, and 0.20 mm and 0.12° for TTFG, respectively. No significant differences were found for accuracy between EMTSs. However, PFG showed a tendency for higher precision than TTFG. AUR, DUR, and 2D US probe did not influence the accuracy and precision of both EMTSs. In opposition, the 4D probe distorted the signal near the attached sensor, making readings unreliable.
Ureteroscopy- and ultrasonography-assisted PRA based on EMTS guidance are feasible with the tested AUR or DUR together with the 2D probe. More studies must be performed to evaluate the probes and ureterorenoscopes' influence before their use in PRA based on EMTS guidance.
电磁跟踪系统（EMTS）已被提议用于辅助微创介入肾系统的经皮肾穿刺（PRA）。然而，在 PRA 期间广泛使用的其他手术器械（如输尿管镜和超声设备）对 EMTS 性能的影响尚不完全清楚。这项工作针对两种 EMTS（Aurora 平面场发生器（PFG）；Aurora 桌面场发生器（TTFG））进行了评估。
开发了一个评估平台，由一个带有特定支架的支架组成，用于固定手术器械，以及一个带有多个水平的板状幻影，用于精确平移或旋转手术器械。使用该平台，在手术环境下，对 PFG 和 TTFG 分别估计了位置和方向的中位精度和精度。然后，评估了不同手术器械（单独或组合），即模拟柔性输尿管镜（AUR）、数字柔性输尿管镜（DUR）、二维（2D）超声（US）探头和四维（4D）机械 US 探头，对两种 EMTS 的影响，通过将仪器与 5-DOF 和 6-DOF 传感器耦合。
总体而言，在手术环境中，PFG 的位置和方向精度的中位数分别为 0.85mm 和 0.42°，TTFG 分别为 0.72mm 和 0.39°，而 PFG 的精度分别为 0.10mm 和 0.03°，TTFG 分别为 0.20mm 和 0.12°。EMTS 之间的准确性没有显著差异。然而，PFG 的精度倾向于高于 TTFG。AUR、DUR 和 2D US 探头不影响两种 EMTS 的准确性和精度。相反，4D 探头会扭曲附着传感器附近的信号，导致读数不可靠。
基于 EMTS 引导的输尿管镜和超声辅助 PRA 是可行的，可与测试的 AUR 或 DUR 以及 2D 探头一起使用。在基于 EMTS 引导的 PRA 中使用之前，必须进行更多的研究来评估探头和输尿管镜的影响。
