NetStation

From Waisman Brain Imaging Wiki

NetStation is an integrated hardware/software solution for recording high-density (128 or 256 channel) EEG signals. It uses geodesic sensor nets rather than traditional sensor-embedded caps to detect the signals, which are then routed to software-controlled amplifiers. The data from the amps is sent over USB cables to dedicated Macintosh computers for recording and analysis.

NetStation is produced by Electrical Geodesics, Inc. (http://www.egi.com/index.html)

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Company Resources

Third-Party Resources

Our Tips & Tweaks

• NetStation produces data files that are in an EGI-proprietary format. That means that we can't open them with any software other than NetStation. In addition, the data files are in Macintosh-specific format, which means that they can't be easily copied to the lab network without losing some critical information (specifically, the "resource" fork of the file, which tells Macs that the files are indeed created by NetStation). If you try to copy them to the lab network and back, you probably won't be able to open them again--they'll be garbage. These files are often referred to as "NSR" or "NetStation Recording" files, or "NetStation original data" files.
  
  
• To work around this "feature", EGI provides with a utility to convert "NSR" files to "RAW" format. This utility is a stand-alone application that is bundled with early versions of NetStation, and is built-in to NetStation in later versions. The "RAW" format is public, so that we know its internal structure and how to read "RAW" files. Plus, it is platform-independent, so we can easily transfer "RAW" files to and from the lab network and to Windows and Linux computers with no problems. However, some information is lost in the conversion from "NSR" to "RAW" format: some event code info is dropped, and the EEG data is pre-scaled (it isn't really raw). So, "RAW" isn't perfect, but it does allow us to analyze the data using Larry's MATLAB routines and other applications like EEGLAB. If you intend to do part or all of your analysis in NetStation, it is better to use the "NSR" files for the NetStation-based analysis. For any other analysis, you must use "RAW" files.
  
  
• NOTE: You cannot recreate "NSR" files from "RAW" files. But it is easy and fast to create "RAW" files from "NSR" files. So be very careful to archive and verify your original "NSR" files.
  
  
• Because of these issues with the data file formats, we've devised a specific methodology for the collection and archiving of NetStation data. Here are the general steps to follow:
  
  
  1. Collect data with NetStation. This is in EGI's proprietary Mac-only "NSR" format.
     
     
  2. Burn collected "NSR" data to CD/DVD. Burn two copies. Label the CD/DVDs clearly and with as much detail as possible. Use CDs if at all possible, and DVDs only if your data files are huge, as CDs are less fragile and more likely to have a longer life in storage.
     
     
  3. Verify the burned CD/DVDs by opening somewhere between a few and all of your data files in NetStation and poking around in each one a bit. If they look funny, check by opening the originals. If the original data files and CD copies don't match, throw away the CDs and re-burn them from scratch.
     
     
  4. Store one copy of the CD/DVDs with the other lab archived disks, hopefully never to be touched again. There's a box in Brogden room 366 for this.
     
     
  5. Trot the other ("working") copy over to a Mac connected to the network (one of the ones in 381; whichever has enough disk space). Copy the data to the networked Mac.
     
     
  6. Convert the data to RAW format if needed. Copy the RAW files to your study directory (/exp/<yourstudy>/... aka W:\exp\<yourstudy>\...). Do your MATLAB/EEGLAB analysis on the network.
     
     
  7. Do whatever NetStation data analysis you need to do on the networked Mac (if any).
     
     
  8. Archive any intermediate/result data files to CD/DVD that take a long time to create or are "tricky" to create. Make two copies, and verify both copies. Put one copy in the "archive disks" box in Brogden 366, and keep the other copy.
     
     
  9. Clear your data off of the networked Mac when you're done with your analysis.
     
     
  10. Write up the results of your brilliant study and get published in Nature Neuroscience (http://www.nature.com/neuro/index.html).
      
      
• Sometimes NetStation gets a little lost. There's a trick that seems to help NS find itself most of the time.
  • For NetStation 3:
    • Quit out of NetStation if it hasn't crashed out by itself.
    • Double-click on the boot disk's icon (this is almost always the top-right-most icon on the desktop).
    • Open the "Documents" folder, then the "NetStation User Data" subfolder within it, then the "Support" sub-subfolder.
    • In it, you should see two files, "Resources Database" and "Tools Database". Drag both files to the desktop.
    • Now try running NetStation again. Better?
      • Yes? Throw away the "Resources Database" and "Tools Database" files from the desktop; NetStation has created new copies and doesn't need the old ones.
      • No? If that didn't seem to help, repeat all of the above steps, but reboot the Mac before you try running NetStation.
    • Another thing to try:
      • Double-click on the boot disk's icon
      • Open the "System Folder" folder, then the "Preferences" subfolder within it.
      • In it, somewhere in the middle of a long list of files, you should find a file called "Net Station 3.0 Preferences". Drag it to the desktop.
      • Reboot and try running NetStation again. If NetStation is happier, throw away the preferences file; NetStation will create a new one.
    • If *that* doesn't help, go find an IT person like Ram, Alanna, John, or Adrian.

    
    

  • For NetStation 4: Finish me!

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