面向虚拟术前切割导板与下颌骨的基于表面的配准技术用于重建手术

中文摘要 AI 辅助

下颌骨重建用于节段切除术后恢复面部连续性与口腔功能。定制化切割导板可将基于计算机断层扫描（CT）的手术计划带三维信息传递至手术室，但打印导板会增加成本与交付周期，制造后无法适配，且若失去无菌性可能中断手术。本文研究一种无标记增强现实（AR）替代方案，通过表面几何结构将虚拟切割导板配准至暴露的下颌骨。该方法将基于表面的配准技术扩展至经口入路场景，其中牙齿构成最具辨识度的可见表面。完成相机标定后，HoloLens 2飞行时间相机采集术中局部点云。用户仅需提供基于头部的粗略对齐以裁剪感兴趣区域。基于牙齿加权的全局阶段计算对应关系并求解截断最小二乘刚性对齐。非对称点到平面迭代最近点（ICP）阶段将完整CT下颌骨与局部深度云目标进行精配准。导板至下颌骨的变换将导板置于HoloLens世界坐标系，同时随目标运动进行位姿更新与插值。本文定义盲法体模方案，包含30个目标配准误差（TRE）点，分别在完全暴露、中等暴露及仅牙齿暴露条件下测试，另加运动到显示延迟测试。结果显示，三种暴露条件下的中位TRE分别为4.05、6.10、7.10 mm，中位延迟为0.805 s。这些数值支持用AR替代物理打印导板的可行性，该流程移除了安装的基准标记与手动地标选择，为经口切割导板提供了可验证的实现路径。

英文摘要

Mandibular reconstruction restores facial continuity and oral function after segmental resection. Patient-specific cutting guides transfer a computed tomography (CT)-based plan to the operating room with three-dimensional information, but printed guides add cost and lead time, cannot adapt after fabrication, and may interrupt surgery if sterility is lost. We investigate a markerless augmented reality (AR) alternative that registers a virtual cutting guide to the exposed mandible from surface geometry. The method extends surface-based registration for the transoral setting, where teeth form the most distinctive visible surface. After camera calibration, a HoloLens 2 time-of-flight camera captures a partial intraoperative point cloud. The user supplies a rough head-based alignment only to crop the region of interest. A teeth-weighted global stage computes correspondences and solves a truncated least-squares rigid alignment. An asymmetric point-to-plane iterative closest point (ICP) stage refines the complete CT mandible against the partial depth cloud target. The guide-to-mandible transform places the guide in the HoloLens world frame, while pose updates and interpolation follow target motion. We define a blinded phantom protocol with 30 target registration error (TRE) points under full, intermediate, and teeth-only exposure, plus a motion-to-display latency test. Our median TRE is 4.05, 6.10, and 7.10 mm respectively, and median latency is 0.805 s. These values support the feasibility of using AR to replace physical prints. The workflow removes mounted fiducials and manual landmark selection and provides a testable path toward transoral cutting guidance.

发表机构

• Vanderbilt University（范德堡大学）

机构由 AI 辅助整理，请以论文原文为准。