Background and objective

The distal interlocking of intramedullary nail remains a technically demanding procedure. Existing augmented reality based solutions still suffer from hand-eye coordination problem, prolonged operation time, and inadequate resolution. In this study, an augmented reality based navigation system for distal interlocking of intramedullary nail is developed using Microsoft HoloLens 2, the state-of-the-art optical see-through head-mounted display.

Methods

A customized registration cube is designed to assist surgeons with better depth perception when performing registration procedures. During drilling, surgeons can obtain accurate and in-situ visualization of intramedullary nail and drilling path, and dynamic navigation is enabled. An intraoperative warning system is proposed to provide intuitive feedback of real-time deviations and electromagnetic disturbances.

Results

The preclinical phantom experiment showed that the reprojection errors along the X, Y, and Z axes were 1.55 ± 0.27 mm, 1.71 ± 0.40 mm, and 2.84 ± 0.78 mm, respectively. The end-to-end evaluation method indicated the distance error was 1.61 ± 0.44 mm, and the 3D angle error was 1.46 ± 0.46°. A cadaver experiment was also conducted to evaluate the feasibility of the system.

Conclusion

Our system has potential advantages over the 2D-screen based navigation system and the pointing device based navigation system in terms of accuracy and time consumption, and has tremendous application prospects.

中文翻译：

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基于增强现实的导航，利用Microsoft HoloLens 2进行髓内钉的远端互锁

背景和目标

髓内钉的远端互锁仍然是一项技术要求很高的程序。现有的基于增强现实的解决方案仍然遭受手眼协调问题，延长的操作时间和不足的分辨率。在这项研究中，使用Microsoft HoloLens 2（最先进的光学透视头戴式显示器）开发了用于髓内钉远端互锁的基于增强现实的导航系统。

方法

设计了定制的注册立方体，以帮助外科医生在执行注册程序时具有更好的深度感知。在钻孔过程中，外科医生可以获得髓内钉和钻孔路径的准确且原位的可视化，并启用动态导航。提出了一种术中警告系统，以提供实时偏差和电磁干扰的直观反馈。

结果

临床前体模实验表明，沿X，Y和Z轴的重投影误差分别为1.55±0.27 mm，1.71±0.40 mm和2.84±0.78 mm。端到端评估方法表明，距离误差为1.61±0.44 mm，3D角度误差为1.46±0.46°。还进行了尸体实验以评估该系统的可行性。

结论

就准确性和时间消耗而言，我们的系统与基于2D屏幕的导航系统和基于定点设备的导航系统相比具有潜在的优势，并且具有广阔的应用前景。