外科医生视线在混合现实中的全息图注册和定位中的价值。

PURPOSE: Mixed reality (MR) is being evaluated as a visual tool for surgical navigation. Current literature presents unclear results on intraoperative accuracy using the Microsoft HoloLens 1. This study aims to assess the impact of the surgeon's sightline in an inside-out marker-based MR navigation system for open surgery. METHODS: Surgeons at Akershus University Hospital tested this system. A custom-made phantom was used, containing 18 wire target crosses within its inner walls. A CT scan was obtained in order to segment all wire targets into a single 3D-model (hologram). An in-house software application (CTrue), developed for the Microsoft HoloLens 1, uploaded 3D-models and automatically registered the 3D-model with the phantom. Based on the surgeon's sightline while registering and targeting (free sightline /F/or a strictly perpendicular sightline /P/), 4 scenarios were developed (FF-PF-FP-PP). Target error distance (TED) was obtained in three different working axes-(XYZ). RESULTS: Six surgeons (5 males, age 29-62) were enrolled. A total of 864 measurements were collected in 4 scenarios, twice. Scenario PP showed the smallest TED in XYZ-axes mean = 2.98 mm ± SD 1.33; 2.28 mm ± SD 1.45; 2.78 mm ± SD 1.91, respectively. Scenario FF showed the largest TED in XYZ-axes with mean = 10.03 mm ± SD 3.19; 6.36 mm ± SD 3.36; 16.11 mm ± SD 8.91, respectively. Multiple comparison tests, grouped in scenarios and axes, showed that the majority of scenario comparisons had significantly different TED values (p < 0.05). Y-axis always presented the smallest TED regardless of scenario tested. CONCLUSION: A strictly perpendicular working sightline in relation to the 3D-model achieves the best accuracy results. Shortcomings in this technology, as an intraoperative visual cue, can be overcome by sightline correction. Incidentally, this is the preferred working angle for open surgery.

目的：混合现实（MR）正被评估为手术导航的一种视觉工具。目前的文献对使用 Microsoft HoloLens 1 的术中准确性结果呈现出不明确的结果。本研究旨在评估基于内部标记的 MR 导航系统在开放手术中对视线的影响。

方法：阿克什胡斯大学医院的外科医生对该系统进行了测试。使用定制的幻影来进行测试，该幻影内部墙壁上包含 18 个线靶十字。进行 CT 扫描以将所有线靶分割成单个 3D 模型（全息图）。为 Microsoft HoloLens 1 开发的内部软件应用程序（CTrue）上传 3D 模型，并自动将 3D 模型与幻影注册。基于注册和目标时的外科医生视线（自由视线/F/或严格垂直视线/P/），开发了 4 种场景（FF-PF-FP-PP）。在三个不同的工作轴（XYZ）中获得目标误差距离（TED）。

结果：纳入了 6 名外科医生（5 名男性，年龄 29-62 岁）。在 4 种场景中总共收集了 864 次测量值，每个场景进行了两次测量。场景 PP 在 XYZ 轴上的 TED 最小，平均值为 2.98±1.33mm；2.28±1.45mm；2.78±1.91mm。场景 FF 在 XYZ 轴上的 TED 最大，平均值为 10.03±3.19mm；6.36±3.36mm；16.11±8.91mm。按场景和轴分组的多重比较测试表明，大多数场景比较的 TED 值具有显著差异（p<0.05）。无论测试的场景如何，Y 轴始终表现出最小的 TED。

结论：与 3D 模型成严格垂直关系的工作视线可获得最佳的准确性结果。术中作为视觉提示的这项技术的缺陷可以通过视线校正来克服。顺便说一句，这是开放手术的首选工作角度。