EEG Instrumentation and Calibration 2

Question 1

What is the standard calibration signal used to verify EEG amplifier function?

Accepted Answer

A 50 µV square wave at 1 Hz

Answer

A 10 µV sine wave at 10 Hz

Answer

A 100 µV triangle wave at 5 Hz

Answer

A 200 µV sine wave at 60 Hz

Question 2

The common mode rejection ratio (CMRR) of an EEG differential amplifier measures its ability to:

Accepted Answer

Reject signals that are identical at both inputs while amplifying their difference

Answer

Amplify all signals equally across the frequency spectrum

Answer

Filter out frequencies above 70 Hz

Answer

Maintain constant impedance across all electrodes

Question 3

The high-frequency filter (low-pass filter) in EEG recording at a typical setting of 70 Hz will:

Accepted Answer

Attenuate frequencies above 70 Hz while passing lower frequencies

Answer

Block all frequencies below 70 Hz

Answer

Only display the 70 Hz component

Answer

Amplify frequencies above 70 Hz

Question 4

What is the minimum recommended sampling rate for routine digital EEG recording?

Accepted Answer

256 Hz

Answer

64 Hz

Answer

128 Hz

Answer

1024 Hz

Question 5

The time constant of an EEG amplifier determines:

Accepted Answer

The rate at which a DC-shifted signal decays back to baseline through the low-frequency filter

Answer

How quickly the amplifier reaches maximum gain

Answer

The maximum amplitude the amplifier can display

Answer

The number of channels that can record simultaneously

Question 6

During a routine EEG, the standard display sensitivity is set to:

Accepted Answer

7 µV/mm

Answer

3 µV/mm

Answer

15 µV/mm

Answer

50 µV/mm