Technology & Tools Flashcards

The International 10-20 electrode placement system divides the head based on measurements that are what percentage of total skull dimensions?

Answer: 10% and 20%

The 10-20 system uses 10% and 20% intervals of total nasion-to-inion and preauricular distances to place electrodes.

Which electrode placement is used for the left eye's recording derivation (E1) in standard AASM PSG montages?

Answer: 1 cm below and 1 cm lateral to the outer canthus of the left eye

AASM recommends E1 placement 1 cm below and 1 cm lateral to the left outer canthus to capture both horizontal and vertical eye movements.

Respiratory inductance plethysmography (RIP) measures thoracoabdominal movement by detecting changes in:

Answer: Inductance of wire coils embedded in elastic bands

RIP bands contain sinusoidally wound wires whose inductance changes as cross-sectional area of the thorax or abdomen changes with breathing.

A patient's PAP device data shows a residual AHI of 15 events/hr despite a fixed CPAP pressure of 12 cmH2O. The waveform pattern shows clustered events. This pattern is MOST consistent with:

Answer: Treatment-emergent central sleep apnea

Clustered central events emerging after initiation of CPAP therapy for OSA is the hallmark of treatment-emergent (complex) central sleep apnea.

What is the primary purpose of using a reference electrode (e.g., M1 or M2) in EEG derivations during PSG?

Answer: To serve as the electrically inactive reference point for differential amplification

Reference electrodes (mastoids) provide a relatively electrically quiet site for differential amplification, allowing the active electrode's signal to dominate the derivation.

The leg EMG electrodes for PLMS detection are placed on which muscle, and at what inter-electrode distance?

Answer: Tibialis anterior; 5–7 cm apart

AASM recommends placing leg EMG electrodes on the tibialis anterior muscle with inter-electrode distance of 2–3 cm apart.

When performing a biocalibration at the start of PSG, asking the patient to hold their breath for 10 seconds primarily tests which channel?

Answer: Respiratory airflow and effort channels

Breath-holding calibration verifies that airflow (thermistor/nasal pressure) and respiratory effort (RIP/piezo) channels correctly show cessation of breathing.