利用工業機械手臂測試系統量測試體踝關節生物力學之研究

Abstract

人體關節之生物力學研究通常在評估關節鬆弛度(勁度)及內部各組織的受力分布，雖然目前已有許多方法被使用來量測關節及其內部組織之力學特性，如植入感應器、關節評估儀器、電腦模擬。但由於人體關節運動是屬於多自由度，且組織有幾何及材料的非線性，因此要如何模擬出人體關節實際的受負載情形及運動路徑並量測到內部組織的受力分布一直是生物力學領域中一大挑戰。 因為人體每個關節都具有六個自由度，因此要準確的說明人體運動的狀態的方式，必須也是六個自由度的運動，而本研究所開發的此關節測試系統係利用機械手臂來控制關節的六自由度運動，同時在機械手臂末端效應器上安裝六軸力規以推算得到關節受力，系統之軟、硬體整合及數學運算則是自行開發一控制介面加以統整。本研究除了關節測試系統的架設，亦將利用本實驗室之動作分析系統來驗證距骨再進行採前拉試驗或距骨傾斜測試的相互移動關係，最後透過試體實驗整合至關節測試系統之控制介面，以提供系統更穩定且快速的控制程序。並由試體實驗的結果驗證關節控制系統及控制方法之可行性。 此系統在生物力學的應用方面主要有兩大功能。分別是可以量得關節在力量控制下的運動軌跡，觀點近似於臨床上的理學檢查。以及執行重複關節運動路徑時，可同時量得該運動路徑下的關節受力。進而利用力學的疊加定理求得關節內部組織的原位力。因此，以機械手臂發展關節測試系統以精確量測關節之運動學及力動學資料，將有助於了解關節的鬆弛度(勁度)表現及內部組織在關節運動中的功能與貢獻。

Biomechanical studies of human joints often aim at determining the joint stiffness and the contribution of the soft tissues in terms of load and strain. Many methodologies have been applied to measure the mechanical properties of those tissues, e.g. implanted transducer, arthrometer, computer modelling. Nevertheless, it remains difficult to simulate the loading conditions applied to the joints since joint motion is multi-degree-of-freedom and joint is geometrically and materially nonlinear. The purpose of this study is to develop a Robot-based Joint Testing System（RJTS）and integrate motion analysis system. Prior to the testing of human joints, computer simulation and animal experiment were executed to facilitate the development of the RJTS.The robotic manipulator can control the joint motion accurately and combine a 6-axis load cell mounted on the end effector of robot to measure loads. In order to integrate the RJTS, an interface coded in Visual Basic was developed to perform the 6-DOF position/force-moment control. Moreover, it was integrated into the RJTS interface for in vitro experiment. To measure the path of joint motion under specific loads and to reproduce a path combining the measurement of simultaneous loads are the two mainly functions of RJTS. Since RJTS is capable of measuring the kinematic and kinetic data of joints accurately and the in situ forces of soft tissues by the principle of superposition, which is helpful to measure the joint stiffness and understand the function and mechanical contribution of soft tissues.