Plugin for post-processing the results of MP decomposition of EEG and creating reports describing the time evolution of selected structures, as proposed in the paper
Electroencephalographic profiles for differentiation of disorders of consciousness by
U. Malinowska, C. Chatelle, M.-A. Bruno, Q. Noirhomme, S. Laureys and Piotr. Durka, BioMedical Engineering OnLine2013, 12:109, available at
http://www.biomedical-engineering-online.com/content/12/1/109
Input: results of MP decomposition (decomposition book, stored usually in a *.b file).
Output:
To run the plugin one needs to run the MP decomposition of the signal first. Depending on the signal length and desired accuracy, this may be a time-consuming task; information about the parameters of MP decomposition can be found in the help for MP decomposition module. To run this plugin one atually does not have to load the actual signal into Svarog (this may be needed to inspect the occurrences of single structures, as described in the following part about the tags), since the plugin operates solely on the decompositions books.
First thing to do in the window opened via "Tools/EEG Profiles (MP)" is choosing the *.b file containing all the structures (mostly Gabor functions, i.e. sines with Gaussian envelope) fitted to the signal by the MP algorithm.
The next, central panel is an interface for setting the filters on the relevant structures in terms of their amplitude (peak to peak), frequency, scale (corresponding to the time width of the structure, approx. half-width of the Gaussian), and phase. Ranges of these parameters define criteria of inclusion of given structures in the report. There can be several structures presented in one report, and they will be organized as separate charts in horizontal subplots. New chart is added with the green "+", an opens a window for choosing the type of structure, type of report and the time interval. Predefined types of structuers with default values of parameters include:
After clicking the "add chart" button, a panel with parameter ranges definig selected structures is added. Default values of these parameter ranges relate to the more or less standard definitions of EEG structures established in the tradition of visual EEG analysis; for example, sleep spindles are by default defined as structures conformin to the following criteria:
Clicking "ok" starts computation of the charts presenting time evolution of selected structures. When the task is finished, "get result" button gets us to the window presenting the charts. We can save these results as a graphic PNG files with resolution selected in the fields at the top of the window, and/or as tags marking the occurence of each of the selected structures. To actually see the chosen structures one needs to load the signal (for computing the profiles we used only the results of MP decomposition) and then open the saved tag via "Tags / Open Tag..." .