Hilbert M, Müller W
Regensburg University Hospital, E.N.T. Department, Germany.
Stud Health Technol Inform. 1997;39:237-45.
Virtual environments provide a new dimension of graphic simulation. The interaction between the human and the computer is now intuitive for the user. The use of virtual reality (VR) gives the user the feeling of participating in a (computer generated) scenario very much like reality. This feeling is an essential requirement for simulation of surgical interventions using digital data. Especially in the fields of sinus and skull-base surgery, computer assisted simulation could present a valuable and effective alternative method for honing endoscopic skills. Traditionally, surgeons gain experience through anatomic preparation and education by more experienced colleagues. Landmarks like skull base, carotid arteria or optical nerve have to be identified intraoperatively in order to orientate in this critical region. Highly sensitive structures can be damaged most easily. The quality of surgical skills can be characterized as the sum of knowledge, individual experience and manual dexterity. It is conceivable that a surgeon's level of training and experience could be significantly increased by use of VR. With this in mind, a VR-based simulator for procedures in sinus surgery will improve most of these parts. To provide the virtual environment, a realistic representation of the region of interest with all relevant anatomical structures is required. Based on data from tomographic imaging studies, a three-dimensional representation of the paranasal sinuses is semiautomatically reconstructed. Textures derived from endoscopic images are superimposed on the virtual anatomic structures and provide better realism. Two main components of the VR interface can be distinguished: the 3-D interaction to guide the surgical instruments and the 2-D graphical user interface for visual feedback and control of the session. Moreover, the 3-D interaction has to be realized by means of Virtual Reality techniques providing a simulation of an endoscope and an intuitive handling of other surgical instruments.
虚拟环境提供了图形模拟的新维度。人与计算机之间的交互现在对用户来说很直观。虚拟现实（VR）的使用给用户一种参与（计算机生成的）场景的感觉，非常类似于现实。这种感觉是使用数字数据模拟手术干预的基本要求。特别是在鼻窦和颅底手术领域，计算机辅助模拟可以为磨练内镜技能提供一种有价值且有效的替代方法。传统上，外科医生通过解剖准备和更有经验的同事的指导来积累经验。在手术中必须识别诸如颅底、颈动脉或视神经等标志，以便在这个关键区域中定位。高度敏感的结构最容易受损。手术技能的质量可以被描述为知识、个人经验和手动灵巧性的总和。可以想象，使用VR可以显著提高外科医生的训练水平和经验。考虑到这一点，基于VR的鼻窦手术模拟器将改善其中的大部分方面。为了提供虚拟环境，需要对感兴趣的区域以及所有相关解剖结构进行逼真的呈现。基于断层成像研究的数据，半自动重建鼻旁窦的三维表示。从内镜图像中获取的纹理叠加在虚拟解剖结构上，提供更好的真实感。可以区分VR界面的两个主要组件：用于引导手术器械的三维交互和用于视觉反馈及会话控制的二维图形用户界面。此外，三维交互必须通过虚拟现实技术来实现，该技术提供内窥镜的模拟以及对其他手术器械的直观操作。
