How to Use CNT in Matlab

Matlab can be customized to use CNT data.

Matlab is a computer programming language and numerical analysis environment developed by Mathworks Inc. As a stand-alone programming language, it can be customized to support a range of data formats, including CNT files. A CNT file contains a binary form of the data produced by some neurophysiology monitoring devices such as an electroencephalograph. You can read and analyze CNT files with a freely available program for Matlab called the Bioelectromagnetism Matlab Toolbox.

Instructions

1. Browse to eeg.cvs.sourceforge.net and click the “Download GNU tarball” link, just below the list of files in the center of the screen. This installer contains the Bioelectromagnetism Matlab Toolbox. The file is rather large (288MB) and may take some time to download.

2. Extract the downloaded file to any location on your computer. To accomplish this, first create a new folder on your computer's hard drive and then double-click the Bioelectromagnetism file you just downloaded. When a list of files appears, select all of the files and drag them into your new folder.

3. Lauch Matlab. When the Matlab desktop opens, click inside the command line, type the line of code below and press “Enter.”

   addpath path\to\folder -end

   Replace “ path\to\folder” with the actual path to the files you extracted in Step 1.

4. Go back to the Matlab command line. Type “eeg_toolbox” (without quotations) and press “Enter.” Wait a few moments for the EEG Toolbox [alpha] dialog box to appear.

5. Click “File” from within the EEG Toolbox window. Hover your mouse over “Open” and then click “Voltage.” The EEG File Load dialog box opens. From the Data Type drop-down menu, select either “Scan41” or “Scan3x,” depending on which type of CNT file you are using. Then click “Browse” and navigate to the location of the CNT file. Double-click on the file; then click “Plot” to load the file into Matlab.

Tips & Warnings

• For additional help, type “doc_bioelectromagnetism” on the Matlab command line and press “Enter.” This brings up the documentation for the program.

References

• Sourceforge: Bioelectromagnetism Matlab Toolbox

Resources

• Sourceforge: EEG CVS Repository (Downloads)