Atsumi Hideki, Matsumae Mitsunori, Hirayama Akihiro, Sato Kenichiro, Shigematsu Hideaki, Inoue Go, Nishiyama Jun, Yoshiyama Michitsura, Tominaga Jiro
Department of Neurosurgery, Tokai University School of Medicine, Isehara, Kanagawa, Japan.
Neurol Med Chir (Tokyo). 2011;51(8):611-6. doi: 10.2176/nmc.51.611.
Flexible endoscopes can be used in areas that are difficult to approach using rigid endoscopes. No current real-time navigation systems identify the tip of the flexible neuroendoscope. We have developed a flexible neuroendoscope mounted with a magnetic field sensor tip position-tracking system and evaluated the accuracy of this magnetic field neuronavigation system. Based on an existing flexible neuroendoscope, we created a prototype with a built-in magnetic field sensor in the tip. A magnetic field measurement device provides a magnetic field with a working volume of 500 × 500 × 500 mm in front of the device. The device consists of a flat field generator that creates a pulsed magnetic field, connected to a system control unit that interfaces with a computer. The magnetic field sensor (1.8 × 9 mm) was sealed in a site 0.9 mm from the endoscope tip. Accuracy of neuroendoscope tracking was measured using a three-dimensional coordinate-measuring machine that measures the position of objects along 3 axes, with an error of about 3 µm. The accuracy for this neuroendoscope with built-in magnetic field sensor was root mean square error of 1.2 mm and standard deviation of 0.5 mm. This magnetic field neuronavigation system enables real-time tracking of the tip of the flexible neuroendoscope. Application of this flexible neuroendoscope to intraoperative navigation appears promising, and may provide new advantages for minimally invasive endoscopic surgery.
软性内窥镜可用于刚性内窥镜难以到达的区域。目前尚无实时导航系统能够识别软性神经内窥镜的尖端。我们开发了一种安装有磁场传感器尖端位置跟踪系统的软性神经内窥镜，并评估了这种磁场神经导航系统的准确性。基于现有的软性神经内窥镜，我们制作了一个在尖端内置磁场传感器的原型。一个磁场测量装置在其前方提供一个工作体积为500×500×500毫米的磁场。该装置由一个产生脉冲磁场的平面场发生器组成，连接到一个与计算机接口的系统控制单元。磁场传感器（1.8×9毫米）密封在距内窥镜尖端0.9毫米的位置。使用三维坐标测量机测量神经内窥镜跟踪的准确性，该测量机可沿三个轴测量物体的位置，误差约为3微米。这种内置磁场传感器的神经内窥镜的准确性为均方根误差1.2毫米，标准差0.5毫米。这种磁场神经导航系统能够实时跟踪软性神经内窥镜的尖端。将这种软性神经内窥镜应用于术中导航似乎很有前景，并且可能为微创内窥镜手术提供新的优势。
