利用機械手臂關節測試系統模擬腳踏運動以利量測試體膝關節合力

Abstract

以往研究膝關節力學的方式主要分為活體研究與試體研究：活體研究雖能量測人體膝關節之運動學資訊，但卻無法得知關節內部詳細之力學表現；而透過六軸機械手臂輔助之試體研究雖能得知動作中之生物力學表現，但卻無從得知屬於試體之活體功能性運動學資訊，故無法模擬其動作並觀察其中生物力學。若能得知屬於試體、具活體意義的運動學資訊，未來便能利用試體實驗模擬自行車運動，並觀察過程中的生物力學變化，以對臨床復健及運動層面上的自行車運動給予建議。 本研究利用膝關節形狀參數所表達的骨頭模型與利用以訓練好的類神經網路輸出的自行車踩踏運動學參數，找出形狀參數對於自行車踩踏運運動六個自由度的敏感度，並結合了三維全域變形及應變量測系統與機械手臂關節測試系統，由此探討腳踏運動對於膝關節之影響。本研究進行腳踏運動模擬，並重建韌帶位置，藉由模型對位可獲完整韌帶位置和骨頭模型，與量測出骨頭運動學資訊，推算出膝關節韌帶之應變。 經由結果得出，若個別改變股骨端的第五個係數以及第六個係數或是個別改變脛骨端的第八個係數以及第十個係數，將會使得類神經網路輸出的腳踏運動六個自由度的運動學參數變化較大。反之，個別改變股骨端的第一個係數以及第九個係數或是改變脛骨端的第一個係數以及第七個係數，會使的類神經網路輸出的運動學參數相較於其他係數不會有太大的改變。可以從結果中發現自行車其行過程中在Flexion(+)/Extension(-)的動作以及Proximal(+)/Distal(-)的動作相較於其他四個字由度的動作有較大的力量、力矩變化，可以建議利用自行車運動作為復健之患者在復健期間應該適當的調整這兩個自由度的動作。

The knee joint is one of the largest joints in humans and plays an important part in various functional movements in daily life, such as walking, going upstairs and downstairs, sitting and standing. Besides, cycling plays an important part in daily life, with functions such as transportation, entertainment, and sports fitness. Cycling is often taken as a rehabilitation treatment for the patients with injury of lower extremities. However, pedaling wrongly may cause injuries of knee joints. Therefore, revealing detail biomechanics of a pedaling knee is important. Biomechanics of knee had been studied mainly by in vivo and in vitro ways. With the in vivo method, kinematics of a living individual can be measured, but not the detail biomechanics. On the other hand, detail biomechanics can be measured by in vitro studies, but not in living, functional movements. Therefore, providing the living kinematics for cadavers to in vitro experiments could help figure out the biomechanics of pedaling. This study combines a three-dimensional overall deformation and strain measurement system (VIC3D) with a robot-based joint testing system to explore the impact of pedal motion on the knee joint. In this study, pedal motion simulations were performed to reconstruct the cartilage surface. Through model alignment, a complete cartilage and bone model can be obtained, and bone kinematics can be measured to calculate knee cartilage deformation and ligament strain. This study uses the bone model expressed by the shape coefficients of the knee joint and the bicycle pedaling kinematics parameters output by the trained neural network to find out the sensitivity of the shape coefficients to the six degrees of freedom of the bicycle pedaling movement. This study combines a three-dimensional overall deformation and strain measurement system (VIC3D) with a robot-based joint testing system to explore the impact of pedal motion on the knee joint. In this study, pedal motion simulations were performed to reconstruct the cartilage surface. Through model alignment, a complete cartilage and bone model can be obtained, and bone kinematics can be measured to calculate knee cartilage deformation and ligament strain. According to the results, if the fifth and sixth coefficients of the femoral are changed individually, or the eighth and tenth coefficients of the tibial are changed individually, the pedal motion output by the neural network will be huge change of six degree of freedom. Conversely, individually changing the first coefficient and the ninth coefficient of the femoral or the first coefficient and the seventh coefficient of the tibial will make the kinematic parameters output by the neural network different from other coefficients. In addition, it can be found from the results of the robot-based joint testing system experiment that the movements of Flexion (+)/Extension (-) and Proximal (+)/Distal (-) during the cycle of the bicycle are compared with the movements of the other four degree of freedom. There are large changes in strength and torque. It can be suggested that patients who use bicycle exercise as rehabilitation should adjust these two degrees of freedom during rehabilitation.