CPSGT cheat sheet

Wake with eyes closed: alpha rhythm 8–13 Hz maximal over occipital regions; alpha attenuates with eye opening.

N1: low-amplitude mixed-frequency EEG, slow eye movements, and vertex sharp waves; alpha occupies <50% of the epoch.

N2: K-complexes (≥0.5 s) and/or sleep spindles (11–16 Hz, ≥0.5 s) without sufficient slow-wave activity.

N3: slow-wave activity 0.5–2 Hz, >75 µV peak-to-peak, occupying ≥20% of the epoch.

REM: low-amplitude mixed-frequency EEG, rapid eye movements, lowest chin EMG, and sawtooth waves.

Arousal: abrupt EEG frequency shift ≥3 s; in REM, requires concurrent chin EMG increase ≥1 s.

Apnea: ≥90% airflow reduction for ≥10 s; hypopnea: ≥30% reduction for ≥10 s with ≥3% desaturation or arousal.

Sleep efficiency = total sleep time ÷ time in bed × 100.

MSLT: 5 naps; mean sleep latency ≤8 min plus ≥2 SOREMPs supports narcolepsy.

Use the 10–20 system: measure 10% and 20% distances from nasion, inion, and preauricular points to place electrodes reproducibly.

Standard EEG derivations: F4-M1, C4-M1, O2-M1, with backup F3-M2, C3-M2, O1-M2.

Keep electrode impedance ≤5 kΩ; high impedance increases 60 Hz and movement artifact.

Prep skin with alcohol and mild abrasive; avoid excessive abrasion that causes bleeding or pain.

Left EOG: 1 cm below and 1 cm lateral to left outer canthus; right EOG: 1 cm above and lateral to right outer canthus.

Chin EMG: two electrodes below the chin and one above, placed midline and separated to avoid bridging.

Place oximeter probe on a warm, perfused finger; remove nail polish and verify waveform.

Before lights out: perform bio-calibration, check impedances, test signals, and document setup.

Record EEG at ≥200 Hz, commonly 200–500 Hz; lower rates may miss brief EEG features.

EEG filters: low 0.3 Hz, high 35 Hz; EOG filters similar; chin EMG typically 10–100 Hz.

A 50 µV square-wave calibration verifies amplifier gain and channel response.

Use 60 Hz notch filter only when needed; first check impedance, ground, and cable routing.

Sweat artifact: slow rolling baseline; dry the skin and improve electrode adhesion.

ECG artifact: regular sharp spikes in EEG/EMG; reposition electrodes and check references.

Event markers identify snores, movements, interventions, and technical events for later scoring.

Tech notes document medications, complaints, interventions, artifacts, lights out/on, and unusual events.

Before the study, explain sensors and procedure; instruct no caffeine or alcohol and washed hair.

Monitor audio/video and alarms; verify sensor signals and patient position throughout the recording.

CPAP titration: adjust pressure to eliminate apneas/hypopneas and maintain SpO2 ≥90%.

Oxygen titration: adjust flow per order to keep SpO2 ≥90%; document flow and response.

If chest pain, dyspnea, or loss of consciousness occurs, call for help, stay with patient, and follow emergency protocol.

Perform hand hygiene before/after contact and disinfect reusable sensors between patients.

Document interventions, patient complaints, technical problems, and provider notifications.

Work within supervised scope; escalate complex decisions and abnormal findings to supervisor.