Department of Kinesiology, University of Massachusetts, Amherst, MA 01003, USA.
Med Sci Sports Exerc. 2012 Jan;44(1 Suppl 1):S86-9. doi: 10.1249/MSS.0b013e3182399f5e.
Since the 1980s, accelerometer-based activity monitors have been used by researchers to quantify physical activity. The technology of these monitors has continuously evolved. For example, changes have been made to monitor hardware (type of sensor (e.g., piezoelectric, piezoresistive, capacitive)) and output format (counts vs raw signal). Commonly used activity monitors belong to the ActiGraph and the Actical families. This article presents information on several electromechanical aspects of these commonly used activity monitors. The majority of the article focuses on the evolution of the ActiGraph activity monitor by describing the differences among the 7164, the GT1M, and the GT3X models. This is followed by brief descriptions of the influences of device firmware and monitor calibration status. We also describe the Actical, but the discussion is short because this device has not undergone any major changes since it was first introduced. This article may help researchers gain a better understanding of the functioning of activity monitors. For example, a common misconception among physical activity researchers is that the ActiGraph GT1M and GT3X are piezoelectric sensor-based monitors. Thus, this information may also help researchers to describe these monitors more accurately in scientific publications.
自 20 世纪 80 年代以来，研究人员一直使用基于加速度计的活动监测器来量化身体活动。这些监测器的技术不断发展。例如，已经对监测器硬件（传感器类型（例如，压电、压阻、电容））和输出格式（计数与原始信号）进行了更改。常用的活动监测器属于 ActiGraph 和 Actical 系列。本文提供了有关这些常用活动监测器的几个机电方面的信息。本文的主要重点是描述 ActiGraph 活动监测器的演变，通过描述 7164、GT1M 和 GT3X 型号之间的差异来实现。然后简要介绍设备固件和监测器校准状态的影响。我们还描述了 Actical，但讨论简短，因为自首次推出以来，该设备没有发生任何重大变化。本文可以帮助研究人员更好地了解活动监测器的工作原理。例如，体力活动研究人员的一个常见误解是 ActiGraph GT1M 和 GT3X 是基于压电传感器的监测器。因此，这些信息也可以帮助研究人员在科学出版物中更准确地描述这些监测器。
