Université Paris-Saclay, ENS Paris-Saclay, CNRS, Centre Borelli, F-94235 Cachan, France.
Université de Paris, CNRS, Centre Borelli, F-75005 Paris, France.
Sensors (Basel). 2020 Mar 30;20(7):1939. doi: 10.3390/s20071939.
The automatic detection of gait events (i.e., Initial Contact (IC) and Final Contact (FC)) is crucial for the characterisation of gait from Inertial Measurements Units. In this article, we present a method for detecting steps (i.e., IC and FC) from signals of gait sequences of individuals recorded with a gyrometer. The proposed approach combines the use of a dictionary of templates and a Dynamic Time Warping (DTW) measure of fit to retrieve these templates into input signals. Several strategies for choosing and learning the adequate templates from annotated data are also described. The method is tested on thirteen healthy subjects and compared to gold standard. Depending of the template choice, the proposed algorithm achieves average errors from 0.01 to 0.03 s for the detection of IC, FC and step duration. Results demonstrate that the use of DTW allows achieving these performances with only one single template. DTW is a convenient tool to perform pattern recognition on gait gyrometer signals. This study paves the way for new step detection methods: it shows that using one single template associated with non-linear deformations may be sufficient to model the gait of healthy subjects.
步态事件（即初始接触（IC）和最终接触（FC））的自动检测对于从惯性测量单元中描述步态特征至关重要。在本文中，我们提出了一种从个体的步态序列信号中检测步幅（即 IC 和 FC）的方法，该方法使用步态模板字典和动态时间规整（DTW）拟合度量来将这些模板检索到输入信号中。还描述了从注释数据中选择和学习适当模板的几种策略。该方法在 13 名健康受试者上进行了测试，并与金标准进行了比较。根据模板的选择，所提出的算法在检测 IC、FC 和步幅时长方面的平均误差从 0.01 到 0.03 秒不等。结果表明，仅使用单个模板即可使用 DTW 实现这些性能。DTW 是在步态陀螺仪信号上执行模式识别的便捷工具。这项研究为新的步幅检测方法铺平了道路：它表明，使用单个模板结合非线性变形可能足以对健康受试者的步态进行建模。
