Schendel Stephen, Montgomery Kevin, Sorokin Andrea, Lionetti Giancarlo
National Biocomputation Center, Stanford University, CA 94305, USA.
J Craniomaxillofac Surg. 2005 Aug;33(4):223-8. doi: 10.1016/j.jcms.2005.05.002.
The objective of this project was to develop a computer-based surgical simulation system for planning and performing cleft lip repair. This system allows the user to interact with a virtual patient to perform the traditional steps of cleft-lip repair (rotation-advancement technique).
The system interfaces to force-feedback (haptic) devices to track the user's motion and provide feedback during the procedure, while performing real-time soft-tissue simulation. An 11-day-old unilateral cleft lip, alveolus and palate patient was previously CT scanned for ancillary diagnostic purposes using standard imaging protocols and 1mm slices. High-resolution 3D meshes were automatically generated from this data using the ROVE software developed in-house. The resulting 3D meshes of bone and soft tissue were instilled with physical properties of soft tissues for purposes of simulation. Once these preprocessing steps were completed, the patient's bone and soft tissue data are presented on the computer screen in stereo and the user can freely view, rotate, and otherwise interact with the patient's data in real time. The user is prompted to select anatomical landmarks on the patient's data for preoperative planning purposes, then their locations are compared against that of a 'gold standard' and a score, derived from their deviation from that standard and time required, is generated. The user can then move a haptic stylus and guide the motion of the virtual cutting tool. The soft tissues can thus be incised using this virtual cutting tool, moved using virtual forceps, and fused in order to perform any of the major procedures for cleft lip repair. Real-time soft tissue deformation of the mesh realistically simulates normal tissues and haptic-rate (>1 kHz) force-feedback is provided. The surgical result of the procedure can then be immediately visualized and the entire training process can be repeated at will. A short evaluation study was also performed. Two groups (non-medical and plastic surgery residents) of six persons each performed the anatomical marking task of the simulator four times.
Results showed that the plastic surgery residents scored consistently better than the persons without medical background. Every person's score increased with practice, and the length of time needed to complete the 11 markings decreased. The data was compiled and showed which specific markers consistently took users the longest to identify as well as which locations were hardest to accurately mark.
These findings suggest that the simulator is a valuable training tool, giving residents a way to practice anatomical identification for cleft lip surgery without the risks associated with training on a live patient. Educators can also use the simulator to examine which markers are consistently problematic, and modify their training to address these needs.
本项目的目标是开发一个基于计算机的手术模拟系统，用于唇裂修复手术的规划和实施。该系统允许用户与虚拟患者进行交互，以执行唇裂修复的传统步骤（旋转推进技术）。
该系统与力反馈（触觉）设备相连，以跟踪用户的动作并在手术过程中提供反馈，同时进行实时软组织模拟。此前，对一名11天大的单侧唇裂、牙槽突裂和腭裂患者进行了CT扫描，使用标准成像协议，层厚为1毫米，用于辅助诊断。使用内部开发的ROVE软件从这些数据中自动生成高分辨率3D网格。为了模拟目的，将生成的骨骼和软组织3D网格赋予软组织的物理属性。一旦完成这些预处理步骤，患者的骨骼和软组织数据将以立体形式显示在计算机屏幕上，用户可以实时自由查看、旋转并以其他方式与患者数据进行交互。提示用户在患者数据上选择解剖标志点用于术前规划，然后将其位置与“金标准”进行比较，并根据其与该标准的偏差和所需时间生成一个分数。然后，用户可以移动触觉笔并引导虚拟切割工具的运动。因此，可以使用这个虚拟切割工具切开软组织，使用虚拟镊子移动软组织，并进行融合，以执行唇裂修复的任何主要步骤。网格的实时软组织变形逼真地模拟了正常组织，并提供了触觉速率（>1千赫兹）的力反馈。然后可以立即可视化手术结果，并且整个训练过程可以随意重复。还进行了一项简短的评估研究。两组（非医学人员和整形外科住院医师），每组六人，对模拟器的解剖标记任务进行了四次操作。
结果表明，整形外科住院医师的得分始终高于没有医学背景的人员。每个人的分数随着练习而提高，完成11个标记所需的时间缩短。对数据进行整理后，显示出哪些特定标记始终是用户识别时间最长的，以及哪些位置最难准确标记。
这些发现表明，该模拟器是一种有价值的训练工具，为住院医师提供了一种在不承担与活体患者训练相关风险的情况下练习唇裂手术解剖识别的方法。教育工作者也可以使用该模拟器来检查哪些标记始终存在问题，并修改他们的训练以满足这些需求。
