Free RST Patient Setup and Instrumentation Questions and Answers — Questions and Answers
Question 1: When performing physiological calibrations prior to a polysomnogram, the technologist asks the patient to look left and then right. Which of the following channels is being primarily evaluated with this action?
- Electrooculogram (EOG) (Correct answer)
- Electroencephalogram (EEG)
- Electromyogram (EMG)
- Electrocardiogram (ECG)
Correct answer: Electrooculogram (EOG)
The EOG channels are used to monitor eye movements. Asking the patient to look left and right creates characteristic out-of-phase deflections in the EOG channels, verifying proper electrode placement and signal response.
Question 2: A sleep technologist measures a patient's head from the nasion to the inion, finding a distance of 36 cm. According to the International 10-20 system, what is the distance from the nasion to the Fz electrode placement?
- 7.2 cm (Correct answer)
- 3.6 cm
- 10.8 cm
- 9.0 cm
Correct answer: 7.2 cm
The International 10-20 system specifies that the distance from the nasion to Fz is 20% of the total nasion-inion measurement. Therefore, 20% of 36 cm is 7.2 cm.
Question 3: During a study, the technologist observes a persistent, rhythmic artifact in the EEG and EOG channels that corresponds with the patient's heart rate on the ECG channel. What is the most likely cause of this artifact?
- Sweat artifact
- Pulse artifact (Correct answer)
- 50/60 Hz electrical interference
- Movement artifact
Correct answer: Pulse artifact
Pulse artifact, or ECG artifact, occurs when an electrode is placed on or near a pulsating blood vessel. The electrical signal of the heart (QRS complex) is then picked up by the nearby electrode, causing a rhythmic artifact synchronized with the heartbeat.
Question 4: A patient arrives for their sleep study and reports having used a thick hair conditioner and styling gel after washing their hair. Which of the following is the most significant challenge the technologist might face during setup?
- Difficulty placing the nasal cannula
- Inaccurate pulse oximetry readings
- High and unstable electrode impedances (Correct answer)
- Incorrect respiratory effort belt placement
Correct answer: High and unstable electrode impedances
Hair products like conditioners and gels can create a barrier on the scalp, making it difficult to achieve low and stable electrode impedances. This can lead to poor signal quality from the EEG electrodes. The patient's skin and hair should be clean and dry for optimal electrode application.
Question 5: Which of the following is the primary purpose of performing bio-calibrations at the beginning of a polysomnography recording?
- To allow the patient to fall asleep more quickly
- To ensure the automated scoring software is functioning
- To document the patient's baseline vital signs
- To verify that all sensors and electrodes are functioning correctly (Correct answer)
Correct answer: To verify that all sensors and electrodes are functioning correctly
Bio-calibrations involve having the patient perform specific maneuvers (e.g., blinking, moving limbs, holding breath) to generate known physiological signals. This process verifies that all electrodes and sensors are placed correctly, are functioning properly, and are accurately reflecting the patient's physiological changes before the study begins.
Question 6: During patient setup, the technologist places respiratory effort belts around the patient's chest and abdomen. What is the primary physiological activity these belts are designed to measure?
- Heart rate variability
- Snoring vibrations
- Paradoxical breathing (Correct answer)
- Body temperature fluctuations
Correct answer: Paradoxical breathing
Respiratory effort belts measure the expansion and contraction of the thoracic and abdominal cavities during breathing. They are essential for identifying respiratory effort and detecting paradoxical breathing, a key indicator of obstructive respiratory events where the chest and abdomen move out of phase.
Free RST Patient Setup and Instrumentation Questions and Answers
When performing physiological calibrations prior to a polysomnogram, the technologist asks the patient to look left and then right.
Which of the following channels is being primarily evaluated with this action?