Schmerber S, Chen B, Lavallée S, Coulomb M, Chirossel J P, Lavieille J P, Reyt E
Clinique ORL du CHU de Grenoble, BP 217, 38043 Grenoble Cedex 9.
Ann Otolaryngol Chir Cervicofac. 2001 Feb;118(1):35-44.
To make the surgical procedure safer and more precise in FESS, a non-invasive markerless computer-assisted system (CAS) is described for intra-operative navigation whenever the critical regions may be affected by surgical manipulation.
Twenty patients with benign diseases of the paranasal sinuses were treated by Computer Assisted Video-endoscopic surgery, between December 1997 and March 1998. For the determination of accuracy and reproducibility of the system, ten anatomical landmarks on each side of the paranasal sinuses were chosen and measured. All of these points were identified on the direct live video-endoscopy image and compared to those obtained with the Optical Digitizing System (Flashpoint 5000(R)), on axial, coronal and sagittal view. The Optical Localizer we used detects the position of the relative coordinates of two rigid bodies made of IR-LED's each, one rigid body is secured to the head' of the patient with a headset, so that patient motion can be tracked, and the second rigid body attached to the operating instrument, leading to direct localization of the tip of the instrument. We use a markerless, skin surface-based registration method, which has the advantage to avoid doing a second CT scan examination usually performed to process the position of the fiducial markers. We register the data from the patient's usual paranasal CT scan.
Computer-assisted surgery does not increase significantly the duration of the operation. Our markerless skin surface points registration method is reliable enabling of the movements patient's head during the procedure. Computer assistance can be used in almost any type of endoscopic sinonasal procedure. We obtained a registration and calibration accuracy of less than 1.5 mm in 89.2% of cases.
CAS enables the surgeon to have a more thorough understanding of the complicated anatomy of paranasal sinuses, and may be especially helpful in revision surgery when normal anatomic landmarks are lacking. Due to the passive optical technology (Passive Polaris(R)), we are continuing clinical studies in ENT surgery in order do improve the system and to simplify its current management.
为使功能性鼻内镜鼻窦手术（FESS）的外科手术更安全、更精确，本文描述了一种非侵入性无标记计算机辅助系统（CAS），用于在关键区域可能受手术操作影响时进行术中导航。
1997年12月至1998年3月期间，20例鼻窦良性疾病患者接受了计算机辅助视频内镜手术。为确定该系统的准确性和可重复性，在鼻窦两侧各选取10个解剖标志点并进行测量。所有这些点均在直接实时视频内镜图像上识别，并与在轴向、冠状面和矢状面上使用光学数字化系统（Flashpoint 5000(R)）获得的点进行比较。我们使用的光学定位器可检测两个由红外发光二极管制成的刚体的相对坐标位置，其中一个刚体通过头戴设备固定在患者头部，以便跟踪患者的运动，第二个刚体附着在手术器械上，从而直接定位器械尖端。我们采用一种基于皮肤表面的无标记配准方法，其优点是避免了通常为处理基准标记位置而进行的第二次CT扫描检查。我们将患者常规鼻窦CT扫描的数据进行配准。
计算机辅助手术并未显著增加手术时长。我们基于皮肤表面点的无标记配准方法可靠，能够在手术过程中跟踪患者头部的运动。计算机辅助可用于几乎任何类型的鼻内镜鼻窦手术。在89.2%的病例中，我们获得了小于1.5毫米的配准和校准精度。
CAS使外科医生能够更全面地了解鼻窦复杂的解剖结构，在缺乏正常解剖标志的翻修手术中可能特别有用。由于采用了被动光学技术（Passive Polaris(R)），我们正在继续进行耳鼻喉科手术的临床研究，以改进该系统并简化其当前管理。
