Technical reliability assessment of three accelerometer models in a mechanical setup
Technical reliability assessment of three accelerometer models in a mechanical setup
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DOI：
10.1249/01.mss.0000239394.55461.08
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发表时间：
2006-12-01
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影响因子：
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通讯作者：
Tremblay, Mark S.
中科院分区：
文献类型：
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作者：
Esliger, Dale W.;Tremblay, Mark S.
目的：利用机械实验室装置确定三种最常用的加速度计模型中哪一种具有最佳的仪器内部和仪器间可靠性。其次，确定加速度和频率对这些可靠性措施的影响。方法：进行三项实验。首先，在液压激振板上分别放置了5个actual、Actigraph和RT3加速度计，并在垂直平面上以不同的加速度和频率同时加速。使用六种不同强度的条件来产生一系列加速度计计数。采用标准偏差、测量标准误差、变异系数和类内相关系数计算信度。在第二和第三个实验中，39个practical加速度计和50个Actigraph加速度计被置于同样的六种条件下。结果：实验1显示RT3的可靠性较差（仪器内和仪器间CV bbb40 %）。实验2和3清楚地表明，practical （CVintra = 0.5%, CVinter = 5.4%）比Actigraph （CVintra = 3.2%, CVinter = 8.6%）更可靠。实际的可变性与条件的加速负相关，而在Actigraph中没有发现加速和可靠性之间的关系。Actigraph的变异性与病情的频率呈负相关，而在practical中，频率与可靠性之间没有关系。结论：在本研究测量的三种加速度计模型中，practical具有最佳的仪器内部和仪器间可靠性。然而，在不同的加速度和频率的实际和活动计数的可变性的差异趋势排除了选择一个优越的模型。我们需要做更多的工作来理解为什么设计用来测量相同物体的加速度计的表现如此不同。
Purpose: To determine which of the three most commonly used accelerometer models has the best intra- and interinstrument reliability using a mechanical laboratory setup. Secondly, to determine the effects that acceleration and frequency have on these reliability measures. Methods: Three experiments were performed. In the first, five each of the Actical, Actigraph, and RT3 accelerometers were placed on a hydraulic shaker plate and simultaneously accelerated in the vertical plane at varying accelerations and frequencies. Six different conditions of varying intensity were used to produce a range of accelerometer counts. Reliability was calculated using standard deviation, standard error of the measurement, coefficient of variation, and intraclass correlation coefficients. In the second and third experiments, 39 Actical and 50 Actigraph accelerometers were put through the same six conditions. Results: Experiment 1 showed poor reliability in the RT3 (intra- and interinstrument CV > 40%). Experiments 2 and 3 clearly indicated that the Actical (CVintra = 0.5%, CVinter = 5.4%) was more reliable than the Actigraph (CVintra = 3.2%, CVinter = 8.6%). Variability in the Actical was negatively related to the acceleration of the condition, whereas no relationship was found between acceleration and reliability in the Actigraph. Variability in the Actigraph was negatively related to the frequency of the condition, whereas no relationship was found between frequency and reliability in the Actical. Conclusion: Of the three accelerometer models measured in this study, the Actical had the best intra- and interinstrument reliability. However, discrepant trends in the variability of Actical and Actigraph counts across accelerations and frequencies preclude the selection of a superior model. More work is needed to understand why accelerometers designed to measure the same thing behave so differently.