RPSGT Electroencephalography & Signal Interpretation Flashcards

What electrode impedance level is considered acceptable for PSG recordings per AASM standards?

Answer: Below 5 kΩ

AASM standards recommend electrode impedance below 5 kΩ to ensure adequate signal-to-noise ratio and signal quality throughout PSG recordings.

The common mode rejection ratio (CMRR) of a PSG amplifier is important because it:

Answer: Rejects electrical noise shared by both recording electrodes

High CMRR enables the differential amplifier to cancel out electrical noise (such as 60 Hz line artifact) that is common to both recording electrodes.

The recommended high-frequency filter (HFF) setting for EEG channels in PSG is:

Answer: 35 Hz

AASM recommends a 35 Hz high-frequency filter for EEG channels to attenuate muscle artifact while preserving clinically relevant EEG frequencies including spindles and K-complexes.

Electrode pop artifact in PSG EEG is caused by:

Answer: Sudden change in electrode impedance

Electrode pop artifact appears as sharp transient deflections caused by sudden changes in electrode-skin impedance, typically from loose, dried, or poorly applied electrodes.

In PSG signal digitization, aliasing occurs when:

Answer: The sampling rate is less than twice the highest frequency of interest

Aliasing is a digitization artifact arising when the Nyquist theorem is violated — the sampling rate must be at least twice the highest signal frequency to prevent false frequencies.

Which pre-study procedure verifies that all EEG channels are functioning correctly by having the patient perform standardized tasks?

Answer: Biocalibration

Biocalibration has the patient perform tasks such as eyes open/closed, deep breathing, teeth clenching, and looking in each direction to verify proper signal detection across all channels.