Use the Filemenu to open or close a file. After the file has been opened,
the signaldialog will appear.
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.
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.
Use the Amplitudemenu to adjust the amplitude (size/gain) of all signals on the screen.
If you want to adjust the amplitude of one particular signal, use Signalproperties.
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.
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 in the same file
- have the same samplerate
- have the same physical dimension (e.g. uV)
- have the same sensitivity (e.g. uV/bit)
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.
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 (size/gain) of
the signal on the screen.
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.
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.
Use the filtermenu to add or remove filters. First select the type of filter: highpass, lowpass, notch, bandpass or bandstop.
Now select the model: Butterworth, Chebyshev or Bessel (a notchfilter has resonator model only).
Then set the frequency(s) of the filter.
Depending on the type and model of the filter, you can adjust the order, Q-factor and passbandripple.
The curve will show the frequency and phase response of the filter.
Now select one or more signals to apply to and click the "Apply" button.
Reviewing the filters can be done in the "Montage" -> "View this montage" menu.
To view the powerspectrum of a signal, Go to Window -> Spectrum.
A small dialog will be opened which shows a list of signals which are on the screen.
Click on a signal of interest and a docked Powerspectrum (FFT) will be opened.
A powerspectrum (FFT) will be made of the corresponding signal.
The amount of datasamples used to perform the FFT equals the data which is
shown on the screen. Increasing or decreasing the FFT blocksize affects the FFT resolution.
The FFT blocksize can be set in Tools -> Options -> Powerspectrum.
This Powerspectrum will be automatically updated when you navigate through the file. Clicking on the
"ctls" button toggles the controls. Here you can switch-on colorbars to highlight different frequency-
regions. The properties of the colorbars (number of colorbars, frequency, color, etc.) can be adjusted
in the options-menu. Go to Tools -> Options en select the Powerspectrum tab. The height of the colorbar
is relative to the sum, peak or average of the the power of all the frequency-bins in that region, according
to the settings in the options menu.
Use the sliders to zoom into a particular area.
When you check the "Squareroot" checkbox, the squareroot of the power will be shown (amplitude).
Printing can be done by clicking on the printbutton. You can print to a printer, file (PDF or Postscript)
or as an image. It is also possible to "print" to a textfile. It exports the data to text (ASCII).
Clicking on the cursorbutton will display a cursor. Use the mouse to drag the cursor.
It is also possible to show the powerspectrum in a separate window. Leftclick on the signallabel.
A small dialog will be opened, now click on "Spectrum". This powerspectrum is static and will not
update when you change the fileposition (pressing PgUp/PgDn etc.). This way you can compare
multiple powerspectra from different signals and/or filepositions.
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.
You can use a floating ruler for measurements. Leftclick on the signallabel of the signal
of interest. A small dialog will appear. Click on Ruler. A floating ruler will appear.
Drag and drop the ruler with the left mousebutton. Rightclick to remove the ruler.
Note: the ruler will appear only when the displaytime (pagetime) is set between 2 and 60 seconds
AND when the amplitude (size/gain) is set between 1 and 2000.
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. Drag and drop the crosshair with the left mousebutton. 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).
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.
You can bind the F1 to F8 keys to eight different montages. This way you can quickly switch
between different montages by pressing key F1, F2, etc.
Go to Montage -> Edit key-bindings for montages.
It is possible to create keyboard shortcuts (bindings) for predefined montages.
Go to Montage -> Edit key-bindings for montages. Click on the first row (F1);
Now you can select a montage. You can assign eight different
montages to keys F1 - F8.
Now you can quickly switch between predefined montages by pressing one of these keys.
Go to Tools -> Options to change the colors like you prefer.
Go to Tools -> Options -> Calibration to calibrate your screen.
This will achieve that the amplitude expressed in units/cm will have
the correct value.
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.
To view the content of the header of a file (patientname, recording, signalproperties like samplerates etc.),
go to file -> info and select the file of interest.
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.
This tool exports the annotations. You can choose to save as a comma separated textfile or
to save as an EDFplus file. If you have opened multiple files, you can choose to export all
annotations of all opened files into one new file. The header of the file which acts as
the "reference" will be copied into the new EDFplus file. The "reference" file can be selected
in the menu Time -> Timereference.
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, bpm, mmHg, etc.)
- 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
to 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 four inputfields:
- label (name of the signal/channel 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)
- multiplier is normally 1.0. Some programs exports their ascii-data expressed in Volts while
the signal is in the microVolt range. By changing the multiplier you can add gain to the signal before converting.
For example, if the ascii-data is expressed in Volts and the signal is in the microVolt range (EEG),
set the physical maximum to 3000, set the physical dimension to "uV" and set the multiplier to 1000000.
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.
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.
This tool converts the ASCII-output (*.txt) of the Finometer (Beatscope) to EDF.
Finometer is a non-invasive stationary blood measurement and beat to beat haemodynamic monitoring system
made by Finapres Medical Systems.
Start Beatscope and open the file of interest.
Go to File -> Export.
- set export type to textfile
- set timeformat to seconds
- check output: header
- set averaging to none
- check datacolumnwidth: delimiter
- set delimiter to semicolon ";"
- check export beats and/or events: beats only
- select the channels you want to export
Now click on the Export-button to create the file.
In EDFbrowser, you'll find the Finometer to EDF converter in the Tools-menu.
In order to create a correct EDF-file header, enter the patients name and a description about
the type of recording/aquisition.
Adjust the startdate and starttime to the date and time when the Finometer registration took place.
Click on the "select file" button to select the Finometer/Beatscope file.
This tool converts an Emsa eeg-file (*.PLG) to EDF+. If the corresponding *.LBK file is
present, the annotations/events will be exported to EDF+ as well.
This tool converts an EDF+D file to multiple EDF+C files. An EDF+D file can contain
interrupted recordings. This converter export every uninterrupted recording to a new
uninterrupted EDF+C file.
This tool can be used for BDF+D files as well.
This tool converts a BDF file to an EDF file. A BDF+ file will be converted to
EDF+, including the annotations/events.
It uses a first order highpass-filter to remove the DC-part of the signal in order
to make the 24-bits samples fit into the 16-bits samples of EDF.
The cutoff-frequency of the highpass-filters can be adjusted for every signal.
You can also select which signals have to be converted into the new EDF(+) file.
Increasing the divider lowers the resolution but increases the range (physical
maximum and minimum)
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
A description of the BDF fileformat can be found at:
http://www.biosemi.com/faq/file_format.htm
A description of the BDF+ fileformat can be found at:
http://www.teuniz.net/edfbrowser/bdfplus%20format%20description.html
note:
A compatibility check of the header of the file is always done when you open an
EDF(+)/BDF(+) file. When a file appears to be incompatible it will not be opened,
you will be informed about the cause of the incompatibility instead.
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
- 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
- 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
The option "Print to BDF" creates a new BDF-file which will contain the signals
(and annotations) 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.
The annotation editor can be used to add, remove or edit annotations.
Start the editor via menu -> Window -> Annotation editor.
To create a new annotation, write the text of the annotation in the description window and set
the onset time. You can set the duration time as well. If the duration time is unknown or not
applicable, set it to the value -1. Now click on the create button.
Instead of manually entering the onset time, you can use a crosshair.
Drag and drop the crosshair and the onset time will be automatically adjusted.
You can use a second crosshair to adjust the duration time.
To modify an existent annotation, click on the annotation in the annotation window.
Adjust the text and or time, manually or drag and drop the annotation marker.
To delete an annotation, click on the annotation in the annotation window and click
on the delete button.
When you are finished editing annotations, save the file in menu -> File -> Save.
Your file will not be altered, instead a copy of your file with the edited annotations
will be made.
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.
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 a file, the borders are cut away (the first characters of the signallabels are missing).
A. In the printerdialog, choose "landscape" and the right papersize (A4) and
adjust the margins in the printerproperties.
For example, set top and bottom margins to 0.85 cm and the left and right margins to 1.27 cm.
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. Why are the annotationmarkers not visible?
A. Go to menu -> Tools -> Options -> Colors. Check "Annotation marker" and make sure that it
has a different color than the background color.
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