Development of the Computer Assisted Neurosurgery (CANS)

计算机和成像技术的最新进展不仅为神经外科医生提供了更好的诊断方法，如计算机断层扫描(CT)和磁共振成像(MRI)，而且也为外科手术辅助器械的研究开辟了新的途径。为了提供准确的CT或MR图像的空间信息，我们开发了一个计算机辅助神经外科导航系统(CANS导航器)，它可以在术前的CT或MR图像上显示手术操作的活动点。该系统由三维数字化仪、个人计算机和图像处理单元组成。利用最新开发的磁场调制技术的三维数字化仪确定树脂探头、三角形指针或带有小型磁场传感器的吸管的空间位置和方位角。使用头皮上的四个基准标记将探头的空间数据转换到患者的术前CT或MR图像上。这种无框架和无臂导航系统将CT或MRI立体定位引入传统的开放神经外科，而不限制手术范围或干扰手术程序。在不久的将来，我们不仅希望提高这一神经外科导航系统的精度，而且希望将功能解剖数据库与外科手术更紧密地结合起来，开发出安全、精确的计算机辅助神经外科手术。

Recent progress in computer and imaging technology not only has provided neurosurgeons with improved methods for diagnosis such as computerized tomography (CT) and magnetic resonance imaging (MRI) but also has opened up new avenues for investigation into ancillary instrumentation for surgical procedures. To make available precise spatial information of CT or MR images for the actual operative procedure, we have developed a computer-assisted neurosurgical navigational system (CANS navigator), which indicates the active point of surgical manipulation on the preoperative CT or MR images. The system consists of a 3 dimensional digitizer, a personal computer, and an image processing unit. The 3 dimensional digitizer utilizing recently developed magnetic field modulation technology determines the spatial position and orientation angles of the resin probe, triangle-shaped pointer, or suction tube with an attached small magnetic field sensor. Four fiducial markers on the scalp were used to translate the spatial data of the probe onto the preoperative CT or MR images of the patient. This frameless and armless navigational system introduces CT or MRI-stereotaxy to conventional open neurosurgery without limiting the operative field or interfering with the surgical procedures. In the near future, we hope not only to improve the accuracy of this neurosurgical navigational system, but also to combine functional-anatomical data base more closely with the surgical procedures to develop a safe and precise computer-assisted neurosurgery.