Peter L. Reichertz Institute for Medical Informatics, University of Braunschweig-Institute of Technology and Hannover Medical School, Mühlenpfordtstr. 23, D-38106 Braunschweig, Germany.
Comput Methods Programs Biomed. 2012 May;106(2):97-103. doi: 10.1016/j.cmpb.2011.10.014. Epub 2011 Nov 29.
One of the key problems in accelerometry based gait analyses is that it may not be possible to attach an accelerometer to the lower trunk so that its axes are perfectly aligned to the axes of the subject. In this paper we will present an algorithm that was designed to virtually align the axes of the accelerometer to the axes of the subject during walking sections. This algorithm is based on a physically reasonable approach and built for measurements in unsupervised settings, where the test persons are applying the sensors by themselves. For evaluation purposes we conducted a study with 6 healthy subjects and measured their gait with a manually aligned and a skewed accelerometer attached to the subject's lower trunk. After applying the algorithm the intra-axis correlation of both sensors was on average 0.89±0.1 with a mean absolute error of 0.05g. We concluded that the algorithm was able to adjust the skewed sensor node virtually to the coordinate system of the subject.
基于加速度计的步态分析的一个关键问题是，可能无法将加速度计附着到下躯干上，使得其轴与受试者的轴完全对齐。在本文中，我们将介绍一种算法，该算法旨在在行走段期间将加速度计的轴虚拟地与受试者的轴对齐。该算法基于合理的物理方法，并针对无人监督的测量环境而构建，在这种环境中，测试人员自行使用传感器。为了评估目的，我们进行了一项包含 6 名健康受试者的研究，并使用手动对齐和附着在下躯干上的倾斜加速度计测量了他们的步态。应用算法后，两个传感器的轴内相关性平均为 0.89±0.1，平均绝对误差为 0.05g。我们得出结论，该算法能够将倾斜传感器节点虚拟地调整到受试者的坐标系。
