School of Physiotherapy and Curtin Health Innovation Research Institute, Curtin University, Perth, Australia.
BMC Med Res Methodol. 2012 Apr 20;12:54. doi: 10.1186/1471-2288-12-54.
This study aimed to develop a translation equation to enable comparison between Actical and ActiGraph GT3X accelerometer counts recorded minute by minute.
Five males and five females of variable height, weight, body mass index and age participated in this investigation. Participants simultaneously wore an Actical and an ActiGraph accelerometer for two days. Conversion algorithms and R(2) were calculated day by day for each subject between the omnidirectional Actical and three different ActiGraph (three-dimensional) outputs: 1) vertical direction, 2) combined vector, and 3) a custom vector. Three conversion algorithms suitable for minute/minute conversions were then calculated from the full data set.
The vertical ActiGraph activity counts demonstrated the closest relationship with the Actical, with consistent moderate to strong conversions using the algorithm: y = 0.905x, in the day by day data (R(2) range: 0.514 to 0.989 and average: 0.822) and full data set (R(2) = 0.865).
The Actical is most sensitive to accelerations in the vertical direction, and does not closely correlate with three-dimensional ActiGraph output. Minute by minute conversions between the Actical and ActiGraph vertical component can be confidently performed between data sets and might allow further synthesis of information between studies.
本研究旨在建立一个翻译方程，以便对每分钟记录的 Actical 和 ActiGraph GT3X 加速度计计数进行比较。
本研究纳入了 5 名男性和 5 名女性，他们的身高、体重、身体质量指数和年龄各不相同。参与者同时佩戴 Actical 和 ActiGraph 加速度计两天。针对每位受试者，我们每天计算全向 Actical 与三种不同 ActiGraph（三维）输出之间的转换算法和 R²：1）垂直方向，2）组合向量，3）定制向量。然后，我们从完整数据集计算出三个适合每分钟/分钟转换的转换算法。
垂直方向的 ActiGraph 活动计数与 Actical 最密切相关，使用算法：y=0.905x，在每日数据（R²范围：0.514 至 0.989，平均：0.822）和完整数据集中具有一致的中度至强转换（R²=0.865）。
Actical 对垂直方向的加速度最敏感，与三维 ActiGraph 输出相关性不强。在数据集之间，Actical 和 ActiGraph 垂直分量之间可以进行准确的每分钟转换，这可能允许进一步综合研究之间的信息。
