ACTIGRAPH AND ACTICAL PHYSICAL ACTIVITY MONITORS: A PEEK UNDER THE HOOD
By D. John, Patty S. Freedson. Medicine & Science in Sports & Exercise, 2012
382 citations recorded by the source corpus.
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 electro-mechanical 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 paper 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.
Subfields: Computer Vision and Pattern Recognition, Electrical and Electronic Engineering, Physiology
View Paper: https://www.semanticscholar.org/paper/c7bb0e2f3dcb61dd1db25314be9a76f2e9b20f40
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In Computer Vision and Pattern Recognition
In Electrical and Electronic Engineering
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Citations in the corpus
- Systematic review of the validity and reliability of consumer-wearable activity trackers (2015, background): “As an alternative, the company supporting ActiGraph accelerometers currently makes firmware updates available to the public via their website, allowing researchers to assess those changes for impact on the measurement properties of the accelerometer [55, 56].”
- Daily physical activity assessment with accelerometers: new insights and validation studies (2013, methodology): “In the mid-2000s Actigraph replaced the model AM7164 by the GT1M and with that switched from a piezoelectric to a capacitive sensor (33).”