Actigraphy and the USB Accelerometer X6-1A Data Logger

actigraphy

Recording human activity is known as actigraphy and is important to the study of sleep disorders, exercising, atheletic performance, geriatrics, and other sciences related to human movement. An actigraph, or actimetry sensor, measures the movements made by the patient. The simplest actigraph is a pedometer, which counts the gross cyclic movement of the body. However, a pedometer doesn't record when a movement occured, to what extent the movement was made, or the direction of the movement. The USB Accelerometer X6-1A data logger made by Gulf Coast Data Concepts utilizes a 3-axis accelerometer to achieve a complete recording of movement in a small, inexpensive package. This device is used by medical research professionals to monitor and quantify the activity of patients.

X6-1A Accelerometer

Click here to purchase for $89

The X6-1A features:

The system is small enough to fit in a pocket or on a belt and the battery can last for up to 7 days (depending on system configuration). Data is recorded to easily readable, comma separated files. Plug the USB Accelerometer into any Linux/Windows/Mac computer and the 1Gb internal memory is recognized as a Mass Storage Device (just like a USB flash drive). The results can be reviewed using the included XLR8R Java application or loaded into any spreadsheet or data analysis package. Read the complete technical capabilities of the USB Accelerometer X6-1A.


Example Application

The constant recording capability of the X6-1A allows for spectral characterization, or "finger printing", of human activities. Illustrated below are several common activities recorded by the X6-1A and processed into energy versus frequency plots. The spectral data was generated using an open source statistical analysis package called "R" and imported into Microsoft Excel for graphing purposes. The script code used can be downloaded here.

Walking Spectral Characteristics

Running Spectral Characteristics

House Work Spectral Characteristics