DennisDean

The answer to this is yes! Alpha, beta, theta and delta band values are computed automatically with the SpectralTrainFig. The spectral bands by which SpectralTrainFig summarizes the frequency spectrum can be set by uploading a band setting file, which can be found in the programs release section. The instructions for the 'Set Bands' function can be found in the readme associated with the source code.

Before I answer the question, I want to stress the importance of reviewing EDF contents before analyzing data stored in an EDF file.

The best way to review an EDF's content is to use one of the many publicly available EDF viewers. The EDF specification page lists publicly available EDF tools. We have made a MATLAB based EDF viewer available. Since most research is collaborative, I would suggest that working groups use the same viewer.

We develop a MATLAB program specifically for reviewing the contents of an EDF file. The program, SignalRasterViewer, is a general purpose utility for checking and viewing the contents of an EDF file.

The European Data Format (EDF) was developed to store data from sleep studies in 1992. Despite enhancements and proposed alternatives, the original EDF format remains the most common way to exchange EDF files. If you are interested in understanding the details of the format, you might want to read the original article or visit the EDF specification site.

#For Programmers# Accessing data from an EDF file can be tricky when starting out since the file structure is little more complication than a CSV file. Fortunately, there are publicly available EDF readers/loaders for most programming languages. The EDF Specification page maintains a list publicly available EDF tools which you might want to review. New EDF loader/reader seem to be made available regularly. I would recommend that you Google EDF, load/read and the programming language you are working with to identify recently released tools.

We have develop a set of EDF tools written in MATLAB that includes an EDF loader. We have posted a MATLAB based tutorial that describes how to use our MATLAB EDF loader to help you get started.

These are great questions!

I will answer in a new topic.

The artifact detection method used in SpectralTrainFig is a spectral threshold based method developed by our Zurich colleagues and first described here. The spectral threshold methods uses two spectral bands (delta band = [0.6, 4.6] Hz, beta band = [40,60] Hz) and identified artifacts relative to a 15 epoch moving average. 30 second epochs that exceed the delta or beta thresholds are identified as artifact and excluded from summary analysis. The recommended thresholds are 2.5 and 2.0 respectively for the delta and beta bands. The program is currently configured to analyze 30 second sleep epochs but could be adapted to analyze 20 second epochs. The motivation for the thresholds are to identify epochs which are 'clearly' artifact. The approach can be interpreted as finding epochs most likely to be contaminated with low and/or high frequency movement. Note that all of the spectral artifact detection thresholds are parameters and can be adjusted from the command line interface (script file).

We decided to develop a set of tools to make spectral analysis easier and in order to achieve our research objectives. A description with examples can be found:

https://github.com/DennisDean/SpectralTrainFig/blob/master/README.md

Also, I have received many questions about spectral analysis from researchers within and adjacent to the sleep field. I would ask if you have a question about spectral analysis or the software above, that you post it in this forum. The questions and answers will be used to update the documentation and to improve the software.