Parameter Aim Adjustment Example When to Adjust
Sensitivity
5-10 µV/mm
Increase
amplitude
overall
Decrease the voltage
required to produce a
deflection.
Change from 7 µV/mm to 5
µV/mm
need to detect low-amplitude
subtle activities i.e. ECI protocol
Decrease
Amplitude
overall
Increases the voltage
required to produce a
deflection.
Change 7 µV/mm to 10
µV/mm)
signals are too strong i.e. waveform
to be cut off or "clipped" at the top
or bottom
Filter
1 - 70 Hz
LFF
HFF
Decrease
amplitude of high
freq
activities
Decrease the HFF
(High-Frequency
Filter)
/LPF (Low pass filter)
setting
Change from 70 Hz to 30 Hz
– the higher further will
flatter ie 70 Hz that
attenuates 30% will
attenuate 100% after
adjusting
Need to reduce muscle artifacts or
high-frequency noise.
But may screen out spike, sharp
component
Decrease
amplitude of low
freq
activities
Increase the LFF (Low-
Frequency-Filter)/HPF
setting
Or decrease the Time
constant
Change from 1 Hz to 10 Hz
or higher – the lower
further will flatter ie 1 Hz
that attenuates 30% will
attenuate 100% after
adjusting
Need to reduce low-frequency
artifacts like sweating artifacts or
baseline drift.
But it may distort the after-spike
slow wave component.
Differential
amplifier
Impedance 100
Ω -10 KΩ
And the balance-
different <2 KΩ
Increase
amplitude from
deep structure
Increase
interelectrode
distance
Change the distance
between Cz to Pz from 6 to
10 cm to detect low
amplitude signal
To detect deep and subtle brain
activities ACNS recommends
interelectrode distances of > 10 cm
for Electrocerebral inactivity (ECI)
study.
Preventing noise Maintain consistent Impedance electrodes 10 To reduce noise that masks the true
