Scaling and Correcting Accelerometer Data Affected by 16CPAN03
In March of 2016, ActiGraph identified an issue that caused a data anomaly (raw data attenuation) on wGT3X-BT activity monitor units shipped between November 7, 2013 and March 24, 2014 which had collected data with firmware versions 1.4.0, 1.4.1, 1.5.0, 1.6.0 or 1.7.0. In order to minimize the impact on academic publications which rely on data from these units, ...
ActiGraph White Paper: IMU Data
ActiGraph has recently released the ActiGraph GT9X Link, which contains an Inertial Measurement Unit (IMU). The IMU sensors and data output units of measure are listed in Table 1 below.
ActiGraph White Paper: Accelerometer Technologies, Specifications, and Limitations
Technology advances and manufacturing efficiency improvements have drastically increased the options and flexibility available to users of accelerometer-based products. These advancements have led to confusion among activity monitor users, and many have been led to believe that device output normalization is an obvious and easy step. In truth, there are ...
ActiGraph White Paper: Low Frequency Extension Filter
ActiGraph's new low frequency extension filter option now allows users to capture data previously unavailable. By adjusting filter criteria to allow more data to be retained in low activity and/or low frequency environments, elderly or other slow moving subjects can be studied. This filter significantly improves response to both ...
ActiGraph White Paper: Actigraphy Sleep Scoring Algorithms
At present there are two algorithms that are primarily used to perform sleep scoring on actigraphy data captured by ActiGraph devices. These are the Cole-Kripke1 algorithm and the Sadeh2 algorithm.
ActiGraph White Paper: Estimating Human Position with the ActiGraph GT3X Triaxial Activity Monitor
With the introduction of 3-axis accelerometers, it is now possible to expand beyond gross measurement of physical activity and classify activity types. The ActiGraph GT3X Triaxial Activity Monitor takes a first step in this direction with an inclinometer feature that indicates whether a subject is standing, sitting or lying ...
ActiGraph White Paper: What is a Count?
ActiGraph routinely fields questions and inquiries regarding the definition of a ‘count’, the unit of measure for activity for ActiGraph’s monitors. Users are concerned about the ambiguity of this term and how it relates to the physical world. Although the origin of the term ‘count’ is unknown ...