User Manual

3. EEG/PSG MEASUREMENT
3.6 Operator's Manual WEE-1000
Attaching the Electrodes (EEG Measurement)
Guidelines for Input Jack
Use
You must follow these guidelines to obtain correct EEG recordings.
Required Electrodes
Do not perform EEG measurement without the Z, C3, C4, A1 and A2 electrodes.
Input Jack Z
Connect the lead from the electrode (Z electrode) attached on the patient’s nasion
to input jack Z on the electrode junction box. This input jack is used to eliminate
AC interference.
The input jack Z is also used for checking electrode impedance.
Input Jacks C3 and C4
The C3 and C4 electrodes are the system reference electrodes for EEG
measurement. Input jacks C3 and C4 must be used for EEG measurement even if
C3 and C4 are not programmed in any montage.
Connect the leads from the electrodes on positions C3 and C4 to input jacks C3 and
C4, respectively.
Input Jacks A1 and A2
The A1 and A2 electrodes are the reference electrodes for skin-electrode impedance
check. Input jacks A1 and A2 in addition to Z, C3 and C4 must be used for the
electrode impedance check.
When checking electrode impedance, connect the leads from the electrodes on
positions A1 and A2 to input jacks A1 and A2, respectively.
Checking Original Electrode Potentials for All Active Electrodes
Check the original electrode potential for all active electrodes by programming a
montage with the system reference (Use the pattern VA (factory default setting) or
select the 0 V button for reference electrode on the Montage dialog box). Refer to
“Programming Patterns” in Section 4 of the electroencephalograph operator’s
manual.
The digital EEG displays the EEG waveform in each channel by subtracting two
electrode potentials selected to a montage. The subtracted result will be incorrect, if
the electrode attachment is not correct, the original electrode potential is flat, or
unstable or artifact is superimposed on the original electrode potential. Omit the
measurement result if the displayed EEG waveform is incorrect.