Scoring your EEG data to perform polysomnography

Tuesday, 02 de June de 2020

Scoring your EEG data to perform polysomnography

I recently came across the need to score the data I collected with EEG. I did all the processing with the BrainVision Analyzer software, but unfortunately the software was not developed to perform sleep staging.

In the research we performed 20 data collections with 32 electrodes using an actiCHamp and Recorder, for each subject we collected the entire night's sleep, at least 10 hours per subject, Saved in .edf format and with an average size of 2 GB each.

The Data was also pre-processed using the BrainVision Analyzer software. Appling a filter, Independent Component Analysis (ICA), Raw data inspection, segmentation, transformed some electrodes and adjusted the reference.

I could have used the raw data by going straight into the folder. In order to use the processed data, I needed to export this data through Export> EDF Export. After that the file was saved in the folder where I defined it as "export" when I created Workspace in Analyzer.

But when I looked for a way to stage this data through the Analyzer, I didn't find it. So I had to look for alternative ways:

One of them was to use Matlab's Toolbox “Hume”. This toolbox uses functions from the EEGLAB toolbox and the Biosig toolbox. This toolbox was developed by Jared M. Saletin PhD from Brown University in partnership with Stephanie Greer PhD.

At the top right are the buttons to add the stage for that moment. Above the eeg data are part of the internship already carried out.

Below is the description of the hume website:

“Hume is an open-source MATLAB program for scoring and analyzing sleep polysomnography and EEG building on the EEGLAB toolbox. Hume allows researchers to unify their sleep EEG workflow across different acquisition systems. If it can be loaded into EEGLAB, Hume can work with it. Hume supports event-marking, artifact-rejection, the generation of sleep statistic reports, inter-scorer reliability comparisons, and storing output in off- and on-line databases (work in progress). ”


On this site the toolbox can be downloaded for free:
https://www.jaredsaletin.org/hume

Another free internship program I found was Neuron Spectrum. This is what I decided to use because it is also free and you do not need to have Matlab installed.

This software is very easy to use. After installation I manage to open the EEG .edf file easily. On the Exam> Import path.

Similar to Hume, the buttons appear at the top, but on the left side. The data appears in the lower region and the display may have changed sensitivity and time period. However, it has several extra functions that I haven't explored yet.


It presents the window “Analysis of the sleep stages”, in which we can see the information and percentages referring to the stage, as well as export them to Excel. And it is not necessary to have completed the internship for this.

 
Neuron Spectrum can be downloaded from the following website: https://kandel.com.br/suporte/software/

Autor:

César Noronha

Guru

cesarnoronha@brainsupport.co