Patient-specific customized cranial implants (CCIs) are designed to fill the bony voids in the cranial and craniofacial skeleton. The current clinical approach during single-stage cranioplasty involves a surgeon modifying an oversized CCI to fit a patient's skull defect. The manual process, however, can be imprecise and time-consuming. This article presents an automated surgical workflow with a robotic workstation for intraoperative CCI modification that provides higher resizing accuracy compared to the manual approach. We proposed a 2-scan method for intraoperative patient-to-CT registration using reattachable fiducial markers to address the registration issue caused by the clinical draping requirement. First, the draped defected skull was 3D scanned and registered to the CT space using our proposed 2-scan registration method. Next, our algorithm generates a robot cutting toolpath based on the 3D defect model. The robot then performs automatic 3D scanning to localize the implant and resizes the implant to match the cranial defect. We evaluated the implant resizing accuracy of the proposed paradigm against the resizing accuracy of the manual approach by an expert surgeon on two plastic skulls and two cadavers. The evaluation results showed that our system was able to decrease the bone gap distance by more than 60% and 30% on plastic skulls and cadavers respectively compared to the manual approach, indicating lower risk of post-surgical complication and better aesthetic restoration.

中文翻译：

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用于单期颅骨成形术的自动植入物尺寸调整

患者特定的定制颅骨植入物 (CCI) 旨在填充颅骨和颅面骨骼中的骨空隙。目前单期颅骨成形术的临床方法涉及外科医生修改超大 CCI 以适应患者的颅骨缺损。然而，手动过程可能不精确且耗时。本文介绍了一种自动化手术工作流程，其中包含用于术中 CCI 修改的机器人工作站，与手动方法相比，它提供了更高的尺寸调整精度。我们提出了一种使用可重新连接的基准标记进行术中患者与 CT 配准的 2 次扫描方法，以解决由临床悬垂要求引起的配准问题。首先，使用我们提出的 2 扫描配准方法对悬垂的缺陷颅骨进行 3D 扫描并配准到 CT 空间。下一个，我们的算法基于 3D 缺陷模型生成机器人切削刀具路径。然后机器人执行自动 3D 扫描以定位植入物并调整植入物的大小以匹配颅骨缺损。我们根据专家外科医生对两个塑料头骨和两具尸体的手动方法调整大小的准确性评估了所提出范例的植入物调整大小的准确性。评估结果表明，与手动方法相比，我们的系统能够将塑料头骨和尸体的骨间隙距离分别减少 60% 和 30% 以上，表明手术后并发症的风险更低，美学修复效果更好。我们根据专家外科医生对两个塑料头骨和两具尸体的手动方法调整大小的准确性评估了所提出范例的植入物调整大小的准确性。评估结果表明，与手动方法相比，我们的系统能够将塑料头骨和尸体的骨间隙距离分别减少 60% 和 30% 以上，表明手术后并发症的风险更低，美学修复效果更好。我们根据专家外科医生对两个塑料头骨和两具尸体的手动方法调整大小的准确性评估了所提出范例的植入物调整大小的准确性。评估结果表明，与手动方法相比，我们的系统能够将塑料头骨和尸体的骨间隙距离分别减少 60% 和 30% 以上，表明手术后并发症的风险更低，美学修复效果更好。