Certified Polysomnographic Technician Certification Certified Polysomnographic Technician Certification Equipment Setup & Calibration 2 — Questions and Answers
Question 1: What is the standard high-frequency filter (low-pass filter) setting for chin EMG channels in PSG?
- 35 Hz
- 70 Hz (Correct answer)
- 120 Hz
- 500 Hz
Correct answer: 70 Hz
The standard high-frequency filter for chin EMG in PSG is 70 Hz, which removes high-frequency noise while preserving the EMG signal.
Question 2: The reference electrode for EEG derivations in PSG is typically placed at which location?
- Nasion
- Mastoid process (A1 or A2) (Correct answer)
- Inion
- Vertex (Cz)
Correct answer: Mastoid process (A1 or A2)
The mastoid processes (A1 for left, A2 for right) are the standard reference electrode sites for EEG derivations in PSG recording.
Question 3: Which respiratory effort monitoring device measures thoracic and abdominal movement using inductive plethysmography?
- Piezoelectric belt
- Respiratory inductance plethysmography (RIP) belt (Correct answer)
- Nasal pressure cannula
- Esophageal manometer
Correct answer: Respiratory inductance plethysmography (RIP) belt
Respiratory inductance plethysmography (RIP) belts measure cross-sectional area changes of the thorax and abdomen to assess respiratory effort.
Question 4: During CPAP titration, what does a technologist do when the patient continues to have obstructive apneas at the current pressure?
- Decrease pressure by 1–2 cm H₂O
- Increase pressure by 1–2 cm H₂O (Correct answer)
- Switch to bilevel PAP immediately
- Wake the patient and reapply the mask
Correct answer: Increase pressure by 1–2 cm H₂O
When persistent obstructive apneas occur during CPAP titration, the technologist increases pressure by 1–2 cm H₂O per AASM titration protocols.
Question 5: What is the purpose of the body position sensor in a PSG recording?
- To detect leg movements
- To record patient weight shifts during arousals
- To document position-dependent respiratory events (e.g., supine vs. non-supine) (Correct answer)
- To measure thoracic effort
Correct answer: To document position-dependent respiratory events (e.g., supine vs. non-supine)
The body position sensor tracks patient position throughout the night to correlate respiratory events and sleep quality with body position, identifying positional OSA.
Question 6: Which artifact in the EEG channel appears as a regular, large-amplitude deflection at ~1 Hz and is caused by cardiac electrical activity?
- ECG artifact (Correct answer)
- Electrode pop artifact
- 60 Hz interference
- Sweat artifact
Correct answer: ECG artifact
ECG artifact appears as regular QRS-like deflections in EEG channels, caused by volume conduction of cardiac electrical signals through body tissue.
Certified Polysomnographic Technician Certification Certified Polysomnographic Technician Certification Equipment Setup & Calibration 2
What is the standard high-frequency filter (low-pass filter) setting for chin EMG channels in PSG?