開顱手術（Craniotomy）是治療頭部受傷患者的常規方法之一。手術完成後需進行顱骨成形手術（Cranioplasty）來固定和修復顱骨。目前在臨床上越來越多醫生在進行顱骨成形手術時使用電動骨科螺絲起子(Electric orthopedic screwdriver)以植入骨釘及固定骨板。然而，因顱骨骨釘較小，裝填較費時且需極為小心。另外，使用電動骨科螺絲起子植入骨釘時，如能將扭矩、轉速最佳化，應能有最好的植入結果，但是過去的文獻中很少對此問題進行深入探討。本研究目標為嘗試改善目前的電動骨科螺絲起子的設計及植入方式，主要包括兩個部分：連續裝填機構的設計與驗證，及骨釘植入顱骨的有限元素分析與實驗。

本研究使用電腦輔助設計（Computer aided design, CAD）軟體設計了一款可適用於電動骨科螺絲起子的顱骨骨釘連續裝填機構。此設計將顱骨骨釘以骨釘座進行固定後裝填在旋轉匣中進行使用。透過3D列印機使用聚乳酸(Polylactic acid, PLA)材料製作所設計機構的各個組件，再經過研磨處理以改善組件表面品質、精度及公差後，組裝完成產品原型，並進行連續裝填與植入功能的測試與驗證。

此外，本研究使用有限元素方法（Finite Element Method, FEM）進行骨釘植入顱骨的顯性動力學（Explicit dynamics）分析。以本研究所建立的骨釘植入顱骨有限元素模型，設定轉速180 rpm、下壓力5N及破壞位移參數(Displacement at failure) 0.2的情形下，骨釘植入顱骨過程中扭矩值初期隨著植入深度增加而增大，最後趨近一穩定值165N-mm。最後，我們使用豬顱骨作為人類顱骨的替代物進行骨釘植入顱骨實驗，並以實驗所量得的扭矩值探討及驗證本研究有限元素模擬結果的準確性。

Craniotomy is a common procedure for treating head injuries, and cranioplasty is performed afterwards to fix and restore the skull. In clinical practice, an increasing number of surgeons are using electric orthopedic screwdrivers for implanting bone screws and fixing bone plates during cranioplasty. However, the small size of skull bone screws makes the loading process time-consuming and requires extreme caution. Additionally, optimizing torque, speed, and downward pressure during the implantation process using an electric orthopedic screwdriver could lead to better implantation outcomes. However, there has been limited research on this topic in the existing literature. This study aims to improve the design and implantation process of electric orthopedic screwdrivers, and focuses on two main aspects: the design and validation of a continuous screw loading mechanism and Finite Element Method and experiments of bone screw implantation into the skull.

Using Computer-Aided Design (CAD) software, a continuous screw loading mechanism suitable for electric orthopedic screwdrivers was designed for skull bone screws. The mechanism used bone screw holders to hold the bone screws in place securely and load them into a rotating chamber. The components of the designed mechanism were 3D printed using polylactic acid (PLA) material. After post-processing, including surface quality and precision improvement, and tolerance adjustment, the assembled prototype was tested and verified for continuous screw loading and implantation functionality.

Furthermore, Finite Element Method(FEM) using explicit dynamics was conducted to simulate bone screw implantation into the skull. A finite element model of bone screw implantation into the skull was established. Under a rotation speed of 180 rpm, a downward pressure of 5N, and a displacement at failure parameter of 0.2, the simulation showed the torque values during the bone screw implantation process initially increased with the implantation depth and eventually reached a stable value of 165 N-mm. Finally, experiments were conducted using porcine skull specimens as substitutes for human skulls to implant the bone screws. The torque values obtained from the experiments were used to validate and verify the accuracy of the finite element simulation results.

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