User and Service Manual
XLTEK EEG32U Amplifier
27
Calibration and Verification
There is no need to calibrate the NeuroWorks Software or the EEG32U headbox. All calibration is done at
the factory before the system is shipped. To verify that the EEG32U headbox system is correctly
calibrated, perform the following procedure:
1. Connect the
EEG32U
headbox to an
XLTEK
acquisition station and turn the system on.
2. Start
XLTEK Database
(XLDB).
3. To start a new study, click
New
.
4. Choose
Edit > Settings > Acquisition
.
5. In the Acquisition tab, set the
Reference Electrode
to
Common
.
6. Design a bipolar montage using pairs of the channels to be verified. For example, to verify C3,
C4, O1 and O2, use a montage with C3-C4 and O1-O2.
7. Apply a sine wave of 50 microvolts, peak-to-peak amplitude, 10 Hz to all channels of the group
using a signal generator. Ensure that there is a 50 Ohm load on the generator output if the
generator is designed to deliver the specified level into this load.
8. Set the
LFF
filter to 0.1, the
HFF
filter to OFF, and the
Notch
filter to OFF.
9. Verify that no sine wave is greater than 50 microvolts peak-to-peak. The accuracy of the gain is
+/- 1%.
NOTE:
For more information on setting up a montage, consult the online Help.
Channel Test
While you are working in the NeuroWorks live recording screen, a channel test may be performed to
verify the integrity of the signal processing from the amplifier input through to the display. A channel test
applies a test signal to all channels. This allows you to examine the waveforms on the screen to see if all
of the channels are functioning.
NOTE:
A channel test does not validate the connection from the patient electrode to
the amplifier input.
To Run a Channel Test
1. In NeuroWorks EEG, choose
Edit > Settings
. The
Edit Settings
box appears.
2. To open the
Acquisition
dialog box, click the
Acquisition
tab.
3. Select Common in the
Reference Electrode
list box and click
OK
.
4. Choose
Controls > Channel Test Signal
. The
Channel Test
control bar appears above the
waveform window.
5. Use the Channel Test toolbar to select the desired wave
shape
,
amplitude
, and
frequency
.
6. To stop the channel test, click
Done
.
Channel Test Signal Control
The Channel Test Signal control in NeuroWorks EEG turns on the channel test signal according to the
last settings saved and displays the Channel Test Signal toolbar. The toolbar has controls for shape,
amplitude and frequency.
