Quantification of inertial sensor-based 3D joint angle measurement accuracy using an instrumented gimbal
Quantification of inertial sensor-based 3D joint angle measurement accuracy using an instrumented gimbal
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DOI：
10.1016/j.gaitpost.2011.05.018
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发表时间：
2011-07-01
期刊：
影响因子：
2.4
通讯作者：
Li, Q.
中科院分区：
文献类型：
--
作者：
Brennan, A.;Zhang, J.;Li, Q.
本研究量化了惯性传感器在3D解剖关节角度测量中相对于仪表万向节的准确性。万向节绕三个轴旋转，并在ISB推荐的膝关节坐标系中直接测量角度。通过使用物理上固定到万向节的传感器附接装置，基本上消除了由于传感器附接（传感器附接矩阵的不准确性）引起的关节角度估计误差，仅留下由于惯性传感器引起的误差。传感器对应的角度估计误差（RMSE）在屈曲/伸展时为3.20度，外展/内收时为3.42度，内旋/外旋时为2.88度。Bland-Altman平均值的最大绝对值为-1. 63度外展/伸展，3. 22度外展/内收和-2. 61度内旋/外旋。本研究中报告的误差幅度意味着，即使在人类步态研究中不可重现的理想条件下，惯性角测量也会出现几度的误差。相反，报告的误差小于先前在人类步态研究中报告的误差，这表明传感器附件也是惯性步态测量中的重要误差源。所提出的装置和方法可用于量化不同传感器系统和方位估计算法的性能，并在人体实验之前验证实验协议。皇冠版权所有（C）2011由Elsevier B. V.出版。保留所有权利。
This study quantified the accuracy of inertial sensors in 3D anatomical joint angle measurement with respect to an instrumented gimbal. The gimbal rotated about three axes and directly measured the angles in the ISB recommended knee joint coordinate system. Through the use of sensor attachment devices physically fixed to the gimbal, the joint angle estimation error due to sensor attachment (the inaccuracy of the sensor attachment matrix) was essentially eliminated, leaving only error due to the inertial sensors. The angle estimation error (RMSE) corresponding to the sensor was found to be 3.20 degrees in flexion/extension, 3.42 degrees in abduction/adduction and 2.88 degrees in internal/external rotation. Bland-Altman means of maximum absolute value were -1.63 degrees inflexion/extension, 3.22 degrees in abduction/adduction and -2.61 degrees in internal/external rotation. The magnitude of the errors reported in this study imply that even under ideal conditions irreproducible in human gait studies, inertial angle measurement will be subject to errors of a few degrees. Conversely, the reported errors are smaller than those reported previously in human gait studies, which suggest that the sensor attachment is also significant source of error in inertial gait measurement. The proposed apparatus and methodology could be used to quantify the performance of different sensor systems and orientation estimation algorithms, and to verify experimental protocols before human experimentation. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.