EDFbrowser manual

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Filemenu

  Use the Filemenu to open or close a file. After the file has been opened,  the signaldialog will appear.


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Signalsmenu

  Use the Signalsmenu to add or remove signals.  If you want to remove only one particular signal,
  leftclick on the signallabel of the signal you want to remove. A small dialog will appear and gives
  you the possibility to remove that particular signal from the screen. See also Signaldialog.


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Displaymenu

  Use the Displaymenu to choose the pagetime (the amount of seconds that must be shown on the screen).
  Be aware that a pagetime of more than five minutes slowsdown the program. Specially when there are
  many signals on the screen and/or high samplefrequencies. 


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Amplitudemenu

  Use the Amplitudemenu to adjust the amplitude of all signals on the screen.
  If you want to adjust the amplitude of one particular signal, use Signalproperties.


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Signallabel

  The signallabel is the name of the signal which is printed on the screen at the start of the trace.
  This little piece of text has some "hidden" functions. When you leftclick on it, the Signalproperties
  dialog will be opened. You can also drag this label with the left or right mousebutton to change
  the offset or amplitude of the signal, see also Adjusting the position and size of the signals.


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Signaldialog

 Use the signaldialog to add one or more signals to the screen. Go to Signals -> Add.
 On top you will see a list of opened files.
 Select (highlight) the file from which you want to add signals. At the left part of the dialog you see a list of
 all the signals which are in the selected file. Select one or more signals and click on the "Add signals"
 button. Now you will see the selected signals on the screen. You can add more signals afterwards,
 just go to Signals -> Add.

 When you want to make a combination (subtraction) of two or more signals, do as follows. Open the signalsdialog.
 Select the file from which you want to add signals. In this example we choose an EEG file which contains
 the signals "P3" and "C3" and we want to subtract "C3" from "P3".
 - Select (highlight) the signal "P3".
 - Click on the "Add" button.
 - Select (highlight) the signal "C3".
 - Click on the "Subtract" button.
 - Click on the "Display Combination" button.
 - The result of "P3" minus "C3" will appear on the screen.

 Now you can add more combinations or simply close the dialog.

 note: It is only possible to make combinations with signals who:
 - are from the same file
 - have the same samplerate
 - have the same physical dimension (e.g. uV)
 - have the same sensitivity (e.g. uV/bit)


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Signalproperties


  You can view or adjust the properties of a specific signal by leftclicking on the signallabel.
  A small dialog will be opened and let you change the amplitude and color.
  You can also remove filters (if any) or remove the signal from the screen.
  Another option is to activate one or more crosshairs for precise measurements.

  Another way to view/change the properties of a signal is to go to Signals -> Properties.
  This will show you a list of all signals which are on the screen. Simply click on the
  signal of interest.


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Adjusting the position and size of the signals

  Leftclick on the signallabel and move the mousepointer up or down while keeping the
  left mousebutton pressed. This will move the signal up or down on the screen i.e. it
  changes the offset of the signal.

  Rightclick on the signallabel and move the mousepointer up or down while keeping the
  right mousebutton pressed. This will increase or decrease the amplitude of
  the signal on the screen.



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Navigation

  Navigation throug a file can be done by using the PageUp/PageDown buttons on your keyboard.
  Use the Arrowkeys to shift the screen one tenth of the pagetime.



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Annotations

  When a file contains annotations, the annotationwindow will appear.
  Just click on one of the annotations to jump to that position in the file.
  This window is dockable. You can change the size of the window, but also the position.
  You can make the window floating as well by dragging it with the mouse. After closing
  the annotationwindow, you can make it appear again via Window -> Annotations.
 


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Filters

  Use the filtermenu to add or remove filters. There are two types available, highpass or lowpass.
  These filters emulate first order analoge filters (RC-filters) with a 6dB/octave slope. After selecting
  a low- or highpass filtertype, select the frequency or time constant and select one or more signals
  to apply.


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Zoomfunction

 You can zoom into a signal/curve on the screen by drawing a rectangle with the mouse.
 Keep the left mousebutton pressed and move the mousepointer in the direction of the
 right lower corner. When you release the left mousebutton, the content of the rectangle
 will be expanded to the whole screen.  You can repeat this step and zoom in again.

 Use the backspace button on your keyboard to zoom out and restore the previous settings.
 After using the backspace button, you can zoom in again by pressing the insert button on
 your keyboard.


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Crosshairs

  You can use one or two crosshairs for precise measurements. Leftclick on the signallabel
  of the signal of interest. A small dialog will appear. Click on crosshair. A crosshair will
  appear and follows your mouse movements. Leftclick to leave the crosshair at a fixed
  position. Now you can add another crosshair. The second crosshair will show you the
  differences (delta) in time and value of the signal(s). Rightclick to remove the crosshair(s).


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Montages

  Montages can be used to store information about which signals should be shown on
  the screen, what combinations (subtractions) should be made and other properties
  like filters, amplitude and color. Once you have loaded a file for review and
  you have added all the signals you want (and/or all the combinations/subtractions) and
  you have adjusted amplitude and colors and/or filters, you can save them as a montage.
  Go to Montage -> Save. A dialog will be opened where you can choose a directory
  and filename to store your montage.
  Next time when you load a file, you can load a montage via Montage -> Load.

  You can view the properties of a montage via Montage -> View saved montages or
  Montage -> View this montage.

  note:

  It is important that the names (labels) of the signals are correct when you use a montage
  to review different files.



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Colors

  Go to Tools -> Options to change the colors like you prefer.



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Calibration

  Go to Tools -> Options -> Calibration to calibrate your screen.
  This will achieve that the amplitude expressed in units/cm will have
  the correct value.



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Timelock / File synchronisation

When you open multiple files, you can choose  to "timelock" all files with
each other. This means that when you navigate (by pressing PgUp/Pgdwn)
this will affect all signals on the screen. When you choose to "unlock" the files,
only the signals of the "reference" file will be moved on the screen. You can
change which file should be the reference in the Time-menu.

There are three kinds of timelock:

- Offset

    The start of the recording of all files will coincide with each other.

- Absolute time

    The clock/date-time of the different files will coincide with each other.
    (this is only usefull when the period of registration overlap eachother)

- Userdefined synchronizing

  Use this option when you want to align two or more files manually.


The time shown in the leftbottom corner represents the time from the
file that acts as the "reference". You can change which file should be
the reference in the Timenu.

You can adjust the horizontal position (time) of two different files by using
two crosshairs. Put one crosshair at a signal of the first file and put the second
crosshair at a signal of the second file. Now click on Time -> synchronize by crosshairs.
Now the position of the two crosshairs (and that particular position of the two files) will
coincide with eachother.



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EDF(+)/BDF to ASCII format converter

 This tool converts all the signals in an EDF or BDF-file to a plain ASCII text-file.
 It supports different samplerates between the signals.

 Four textfiles will be created:

  - EDFfilename_header.txt  contains the general header of the file.
  - EDFfilename_signals.txt contains all signal headers of the file.
  - EDFfilename_data.txt    contains the data of all signals.
  - EDFfilename_annotations.txt contains all annotations.

  filename_data.txt contains a separate line for each sampletime that occurs.
  Note to windows-users: these lines are separated by a linefeed only,
  so the file does NOT look OK in Notepad, use Wordpad instead.

  Each line contains the comma-separated values of the sampletime and of all
  samples that were taken at that time.
  Sampletime is expressed in seconds, while sample values are expressed in the
  physical dimensions that are specified in filename_signals.txt.
  All values have a dot (.) as decimal separator.

  Different sampling frequencies are allowed in the file. In that case,
  not all signals are sampled at each sampletime.
  Those sample values are simply left empty, but the comma-separator is there.

  note:

  All comma's in headertext and annotations will be replaced by
  single quotes (') because they interfere with the comma-separated
  txt-files.

  Unicode/UTF-8 decoding in annotations is not supported because of
  the limitations of the ASCII txt-files.


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 ASCII to EDF format converter

 This tool converts an ASCII-file to EDF. The following rules apply:

 - the data in the ASCII-file must be presented in their physical dimension (i.e. uV)
 - the data in the ASCII-file must be organised in columns and rows
 - a row must contain values from different signals/channels aquired at the same sampletime
 - a column must represent a continuous sampled signal/channel
 - all signals/channels must have the same samplefrequency
 - the timeinterval between two consecutive samples of the same signal/channel must have a stable value
   (fixed samplerate)

 Enter the following parameters:

 - the character that separates the different columns (i.e. "tab" ","(comma) ";"(semicolon) " "(space) etc.)

 - the number of columns

 - the line at which the data starts. some ASCII-files contain headers, so use this entry
   tell the converter to skip n-lines before interpreting the data

 - samplefrequency

 - patientname

 - recording (a description about the type of recording/aquisition)

 - startdate and time of the aquisition

 - signals: for every column in the ASCII-file, there is a row in the signals-table.
                  every row has a checkbox and three textinputfields:

   - label (i.e. FP1, SaO2, Heartrate, etc.)
   - physical maximum (the maximum physical value that can occur, i.e. the maximum inputlevel
     of the aquisition equipment. A common value in EEG applications is 3000 uV)
     physical minimum will be equal to physical maximum. for example, if you enter 3000, the
     range will be from +3000 to -3000
   - physical dimension (i.e. uV, %, mmHg, bpm)

 It is possible to exclude columns, by unchecking the corresponding row in the signals-table,
 this can be usefull when a column contains a time/datestamp or when you don't want to include
 a particular signal in the EDF-file.

 Click on the startbutton to start the conversion.
 Click on the savebutton to save the entered parameters in a template.
 Click on the loadbutton to load parameters from a template.


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Nihon Kohden to EDF(+)  format converter

 This tool converts EEG-files in Nihon Kohden format to the European Data Format
 (EDF or EDF+ with annotations/events).

 Three files are needed for a conversion to EDF+:

  - nihonkohdenfile.eeg
  - nihonkohdenfile.pnt
  - nihonkohdenfile.log

  In case you have only the nihonkohdenfile.eeg you can not convert to EDF+.
  It is still possible to convert to EDF. In that case there will be no annotations/events and patientinfo.

  Note that not all Nihon Kohden devices are supported by this tool.
  At this moment it supports the following devices:

  - EEG-1100
  - QI-403A
  - EEG-2100
  - DAE-2100


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EDF(+) and BDF compatibility checker

 This tool checks if a file is EDF(+) or BDF compliant.
 It checks the data and all the annotations and timestamps.
 When it finds an error, it tells you what the error is and where it is in the file.

 The official description of the EDF and EDF+ fileformat can be found at:

 http://www.edfplus.info

 note:

 A compatibility check of the header of the file is already done when you open an
 EDF(+)/BDF file for review. When a file appears to be incompatible it will not be
 opened, you will be informed about the cause of the incompatibility instead.


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Print to EDF

  The option "Print to EDF" creates a new EDF-file which will contain the signals
  (and annotations) as they are on your screen. What you see is what you get,
  like when you print to a printer, PDF-file or image. You can also open multiple
  files, shift them in time (by using the different timelock options in the timemenu)
  and "print" the result as one new EDF-file. The result wil contain the time-shifted
  signals.
  It is also possible to extract one or more signals from one (or more) files into a new file.

  This function is located in File->Print menu.

  The following rules apply:

  - the length (duration) of the new file will be equal to the selected displaytime (pagetime)

  - combined signals (subtractions) will become one signal like they are on your screen

  - only EDF- and EDF+-files can be printed to EDF (multiple files is possible)

  - in case of multple files, the new file will get the patientname, recording, date and time
    of the file that has the reference at the moment of printing,
    you can select the reference in the Time-menu

  - discontinues EDF+ files (EDF+D) can not be printed to EDF(+)

   - if (one of) the file(s) is of type EDF+, the outputfile will be an EDF+ file as well,
    otherwise EDF

  - when selected multiple files, the datarecordduration of these files
    needs to be the same or an integer multiple of eachother

   - if you selected any filters, these will be applied as well


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Print to BDF

  The option "Print to BDF" creates a new BDF-file which will contain the signals
  as they are on your screen, in the same way like the "Print to EDF" function,
  except that it is also possible to print EDF(+) files to BDF. You can even mix
  EDF and BDF files onto your screen and print them to a new BDF file.


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Commandline options

  edfbrowser [datafile.edf] [mymontage.mtg]

  It is possible to start the program from the commandline:

  edfbrowser.exe

  this will start the program.

  or

  edfbrowser.exe myfile.edf

  this will start the program with the file myfile.edf opened.

  or

  edfbrowser.exe myfile.edf mymontage.mtg

  this will start the program with the file myfile.edf opened and using the montage mymontage.mtg.

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FAQ

 Q.  How do I add signals to the screen?

 A.  Use the signalsdialog.


 Q.  How can I change the amplitude of a signal?

 A.  Leftclick on the signallabel of that signal. A small dialog will appear. There is a
       spinbox that will let you change the amplitude of the signal.
       Another way is to rightclick on the signallabel and move the mousepointer up or down
       while keeping the right mousebutton pressed. This will increase or decrease the amplitude
       of the signal on the screen.

 Q.  How can I see the value of a signal?

 A.  Use a crosshair.


 Q.  I added signals from multiple files but some of them are not visible on the screen.

 A.  Go to the "Time" menu and set it to "Synchronize start of files".
       Then select Time -> Go to start of file.
        Now select Amplitude -> Fit to pane.


 Q.  I want to open two files in different windows.

 A.  Start the program twice and you can open files in different windows.


  Q.  When I try to open a file, it says that the file is not EDF(+)/BDF compliant.
       What do I do?

 A.  Try to find out what program created that file. Write the maker/developer of that
       program and tell him/her that the program does not produce valid EDF(+)/BDF files.
       Ask him/her to fix that program.


  Q.  When I print to a PDF file, the traces look grey instead of black when I open the file
       in Adobe Reader 8.x.

 A.  In Adobe Reader, go to Edit->Preferences->Page Display and uncheck "Smooth line art".


  Q.  What are the system requirements?

 A.  There are no special requirements. However, the faster your CPU and the more memory,
       the faster you can navigate. For example, a large pagetime (five minutes or more) will make
       the responsetime of the program longer, specially when you add a lot of signals and/or
       when the samplerate is high.
       When you open a file with a size of hundred megabytes and you choose to make the whole
       recording visible on the screen, the program will load the whole file (hundred megabytes)
       into memory.


 Q.  Which operatingsystems are supported?

 A.  Linux and Windows 2000/XP.


 Q.  Which license is used for the program?

 A.  The GNU General Public License version 2. For more info go to Help -> About.


 Q.  I think I found a bug. Where do I report it?

 A.  First check if you are using the latest version of EDFbrowser.
       If the bug persists, send an email to teuniz@gmail.com



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