Sampling rate influences the regularity analysis of temporal domain measures of walking more than spatial domain measures.
Sampling rate influences the regularity analysis of temporal domain measures of walking more than spatial domain measures.
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DOI：
10.1016/j.gaitpost.2021.05.031
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发表时间：
2021-07
期刊：
影响因子：
2.4
通讯作者：
Yentes JM
中科院分区：
文献类型：
--
作者：
Fallahtafti F;Wurdeman SR;Yentes JM
步行的时空动力学可以提供有用的信息，步行性能。大多数情况下，步态运动的识别是使用3-D电影摄影来执行的。运动捕捉系统的采样率可能会影响这些测量的准确性，尽管在不同程度上的空间与时间域内的测量。采样频率对空间和时间域内常用的测量分析方法有何影响？具体而言，平均值，变异性（即标准差），和规律性（即样本熵）的步长（即空间域）和步时间（即时间域）的措施进行了评估后，11名年轻人的首选速度跑步机步行10分钟。时空平均测量值不受采样频率变化的影响。频率≥ 120 Hz时，空间变异性测量结果一致，而在120 Hz或更低频率下采样时，由于捕获变异性的分辨率降低，时间变异性增加。在评估规律性时，较低采样率下的时间分辨率差导致“分箱”，限制了矢量模式的多样性。结果，更多的向量被归类为相似的，导致信号看起来更周期性。对于空间域，样本熵不受影响，这表明与步长相比，步长对采样率的敏感性更大。采样率影响步态事件的识别。通过降低采样率，增加了时间间隔并降低了分辨率，导致时间域中步态事件检测的准确性降低。120 Hz的采样率是用于计算变异性和样本熵的时空数据的最低采样率。
The spatiotemporal dynamics of stepping can provide useful information about walking performance. Most often, the identification of gait motion is performed using 3-D cinematography. The sampling rate of motion capture systems may influence the accuracy of these measures albeit in varying degrees for measures within the spatial versus temporal domain. What are the effects of sampling frequency on common analysis methods of measures within the spatial and temporal domain? Specifically, mean, variability (i.e. standard deviation), and regularity (i.e. sample entropy) of step length (i.e. spatial domain) and step time (i.e. temporal domain) measures were assessed following ten minutes of preferred-speed treadmill walking in eleven young adults. The spatiotemporal mean measures were not affected by changing sampling frequencies. Frequencies ≥120Hz showed consistent results for spatial variability measures, while temporal variability increased due to decreased resolution in capturing variability when data was sampled at 120Hz or less. In assessing regularity, poor temporal resolution at lower sampling rates led to “binning”, limiting the variety of vector patterns. As a result, more vectors were classified as similar, leading to a signal appearing more periodic. For the spatial domain, sample entropy was not affected, indicating the greater sensitivity of step time to sampling rate compared to step length. Sampling rate influenced recognition of gait events. By reducing the sampling rate, the time intervals were increased and reduced the resolution leading to less accurate gait event detection in the temporal domain. The sampling rate of 120Hz is the minimum sampling rate that should be used to calculate spatiotemporal data for variability and sample entropy.
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影响因子：
2.4
作者：
Yentes JM;Denton W;McCamley J;Raffalt PC;Schmid KK
通讯作者：
Schmid KK
DOI：
10.1080/15412555.2020.1750578
发表时间：
2020-04-16
影响因子：
2.2
作者：
Yentes, Jennifer M.;Fallahtafti, Farah;Rennard, Stephen I.
通讯作者：
Rennard, Stephen I.
影响因子：
2.7
作者：
McCamley, John D.;Denton, William;Yentes, Jennifer M.
通讯作者：
Yentes, Jennifer M.
影响因子：
2.4
作者：
Zeni, J. A., Jr.;Richards, J. G.;Higginson, J. S.
通讯作者：
Higginson, J. S.
影响因子：
2.4
作者：
O'Connor, Ciara M.;Thorpe, Susannah K.;Vaughan, Christopher L.
通讯作者：
Vaughan, Christopher L.