Free RST Instrumentation, Equipment & Data Acquisition Questions and Answers

Question 1

Which electrode placement is critical for measuring brain wave activity during polysomnography?

Accepted Answer

C3-A2 and O2-A1

Answer

C3-A2 and O2-A1 are standard electrode placements for measuring brain wave activity (EEG) during polysomnography, particularly for sleep staging. C3 and O2 represent central and occipital cortical areas, respectively, while A1 and A2 are reference electrodes on the mastoids. These placements are crucial for identifying the characteristic waveforms of different sleep stages, such as sleep spindles and K-complexes in NREM sleep, and low-amplitude mixed-frequency activity in REM sleep.

Question 2

What is the purpose of a thermistor in sleep studies?

Accepted Answer

To detect airflow (oral/nasal breathing)

Answer

A thermistor is a sensor used in sleep studies to detect airflow by measuring temperature changes at the nose and mouth. During inhalation, cooler ambient air passes over the thermistor, causing a temperature drop, while during exhalation, warmer exhaled air causes a temperature rise. This allows for the identification of breathing patterns, apneas (cessation of airflow), and hypopneas (reduced airflow).

Question 3

Which sensor is used to measure respiratory effort during polysomnography?

Accepted Answer

RIP belts

Answer

Respiratory Inductance Plethysmography (RIP) belts are sensors used in polysomnography to measure respiratory effort. These elastic belts are placed around the chest and abdomen and detect changes in circumference as the chest wall and abdomen expand and contract during breathing. This allows for the differentiation between obstructive events (where effort is present) and central events (where effort is absent).

Question 4

What does the submental EMG channel primarily assess?

Accepted Answer

Muscle tone for sleep staging

Answer

The submental EMG (electromyogram) channel is primarily used in polysomnography to assess muscle tone, which is a critical parameter for sleep staging. During REM sleep, there is a characteristic loss of muscle tone (atonia), which is clearly visible on the submental EMG. Conversely, higher muscle tone is observed in wakefulness and NREM sleep, helping differentiate these stages.

Question 5

Which parameter is measured by a pulse oximeter during a sleep study?

Accepted Answer

SpO2 (oxygen saturation)

Answer

A pulse oximeter is a non-invasive device used during a sleep study to continuously measure the percentage of oxygen-saturated hemoglobin in the blood, known as SpO2. This measurement is crucial for detecting oxygen desaturations, which are drops in blood oxygen levels often associated with apneas and hypopneas, indicating the severity of sleep-disordered breathing.

RST - Registered Sleep Technologist Practice Test

RST - Registered Sleep Technologist Practice Test

Free RST Instrumentation, Equipment & Data Acquisition Questions and Answers