THE MOTION MEASUREMENT OF HUMAN UPPER LIMB BASED ON ELECTROMAGNETIC TRACKING SYSTEM

摘要

The measurement and analysis of human motion is widely used in rehabilitation, athletics, ergonomics, diagnosis, bionics and computer graphics etc. We have developed a motion measurement and analysis system for human upper limb based on PolhemusTM electromagnetic tracking system in this paper. Firstly, according to the skeleton structure of human, the out-of-perpendicular joint coordinate systems were built in elbow and wrist joint, and put forward a new method to determine the actual orientations of elbow flexion-extension axis and wrist flexion-extension axis, redefined the seven degrees of freedom (DOF) of human upper limb. Secondly, put forward an improved algorithm to calculate motion parameters of upper limb based on above-mentioned model. This algorithm can calculate the above-mentioned orientations and the range of seven DOF in motion with data collected by the electromagnetic sensors, and successfully programmed the algorithm with MATLAB. Thirdly, the Activities of Daily Living (ADLs) of human upper limb are studied, 16 basic actions have got by disassembling and abstracting ADLs. As a result, these basic actions can substitute for ADLs when we research on the range of motion (ROM). Finally, an experiment was performed to verify the correctness of the algorithm and the program. We measured basic actions of human arm in ADL using electromagnetic system, and got the range of seven DOF in motion using MATLAB program. The test shows that the measurement and analysis system based on electromagnetic system is an accurate and easy way for motion measurement of upper limb.