在嚴重骨折中一骨塊可能完全斷裂成兩破裂骨塊，在手術中需要進行破裂骨塊復位，以確保破裂處可銜接復原，此一骨塊復位程序需要精密的手術，稱為｢骨復位手術｣。傳統上使用開放式手術以人工操作方式將破裂骨塊復位到其原始位置，由於術中醫學影像技術的進步，此種手術已可使用微創手術的方式進行，更新的技術則可使用機械手臂進行骨塊復位的操作，以達到更佳的精度與可靠性。臨床上使用機械手臂進行骨復位手術仍然很少，主要原因為缺乏專用於此一領域之機械手臂的發展，因為相關機械手臂機構的發展並非僅考慮機構層面而已，更需要考慮手術中破裂骨塊隱藏在肌肉背後種種複雜的現象與問題。 本計畫的目的為設計一專用於骨復位手術之機械手臂，擬發展一全新的機械手臂機構，以3-RPS之平行式機構為基礎，結合一雙三角之六邊形星形結構，並由兩組RPS所組成。經由先期的研究探討，已對該機構進行完整的分析，其最佳化設計與運動學表現有關，以力量傳遞為規則建立最佳化設計，並且以最小工作空間與最小相互作用力的需求為最佳化之拘束條件。 本研究擬研究骨復位手術所需之機械手臂機構設計，使用實驗室發展之骨復位術前模擬軟體-PhysiGuide，進行一系列模擬，決定機械手臂機構設計規格。骨復位手術模擬所需真實病患之CT影像，及肌肉組織與破裂骨塊間相互間作用力的資訊，將由合作醫師提供。本研究也將完成所設計機械手臂之雛型製造，並執行一系列實驗以驗證機械手臂可依據PhysiGuide軟體規劃之路徑運動，也將測試此一機構可平衡來自於肌肉作用於骨塊的力量。為進行平衡肌肉作用力的實驗，本研究也將設計一平台，於其上裝置骨塊模型，並使用彈簧與可調式鋼線以模擬肌肉之作用力。 ;In severe fracture cases, a bone can be completely separated into two fragments. In order to guarantee a re-ossification of the bone, it is mandatory to reposition the bone fragment together. This process requires a delicate surgery called “bone reduction surgery”. Originally, the operation consisted in manipulating the bones fragments by hand in open surgery. But the development of intra-operative imaging, it has been then possible to perform a minimally invasive version of this type of operations. The most advanced technique rely on the use of a robotic manipulator to manipulate the bone fragment with higher precision and stability. The state of the art of this field is still limited as it is relatively recent compared to general medical robotics. Moreover, the diversity of mechanical architecture used for existing prototypes is also limited and they do not seem to result from a studies focused on the kinematic aspects.This objective of this project proposal is to design a new robotic system dedicated to bone reduction surgery. For the design of the robotic manipulator, a new mechanical architecture is proposed. It is based on a 3-RPS parallel mechanism combined with a double-triangle hexagonal star composed two combinations of RPS. After the complete analysis of this mechanism, its optimization will be based on the kinematic performance, and the force transmission as criteria to optimize and on the minimum required workspace and minimum required force interaction as constraints.The kinematic specification associated with the bone reduction surgery will be obtained from a series of simulations performed on a locally programmed software dedicated to preplanning reduction surgery, namely PhysiGuide. These simulations will be based on real patients’ data provided by our medical collaborator. The force interaction generated by the patient’s muscular tissue on the bone fragments will be provided by our medical collaborator. Once manufactured, a series of experiment will be performed on the robotic prototype in order to verify its ability to generate the appropriate trajectories issued by the PhysiGuide software. The prototype will be also tested on its ability to counter balance the force interaction of the muscular tissues. A specific platform composed of bone models attached with adjustable cables and springs will be designed and mounted in this regards.
