C-arm X光攝影機因為機動性高、取像速度快、及造影成本低等特性，是骨科手術常用的工具，但為了有效確認刀具的方位，須頻繁地拍攝以更新影像，致使病患在手術過程中承受高劑量的輻射，對醫療人員而言，長期累積的放射線劑量亦嚴重威脅身體健康，因此，如何有效減低C-arm的操作時間或使用量，並維持甚或提高手術精度，對於病患或醫療人員都是重要的考量。本研究目的在發展以C-arm影像作為手術導引與定位依據的技術，可在拍攝兩張影像的情況下，在術前由影像中相對應的成像位置計算目標點空間座標，以量測病灶的幾何尺寸，作為規劃手術的依據。手術進行過程中，可將刀具軸向即時地投影在經過畸變校正的C-arm影像上，讓醫師確認刀具與病灶的相對方位關係，達到導引定位之目的。應用此一技術建構之電腦輔助系統已於前十字韌帶重建手術中驗證其可行性與實用性。

Due to high mobility, fast imaging, and low manipulation cost, C-arm fluoroscopy is frequently used for orthopedic surgery. However, mass use of C-arm fluoroscopy for confirmation of operation results is harmful to the health of the patient and medicine persons because of accumulated dosage of radiation. In this research, we have developed image-guided stereotactic technology. Only two images are needed to determine spatial positions and orientations of the targets. A prototype of surgical navigation system has been built. The system provides the functions of preoperative planning by selecting the surgical path on the two C-arm images and intraoperative guidance by watching the difference of the preplanned and real surgical paths. This system has been also applied to preliminary clinical test of anterior cruciate ligament reconstruction (ACL Reconstruction) to verify its clinic feasibility and practicability.

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