During a sleep study or polysomnogram (PSG), these instruments record these activities:
- EEG (electroencephalogram) for brain wave activity
- EMG (electromyogram) for muscle activity like face twitches, teeth grinding, and leg movements
- EOG (electrooculogram) for eye movements important in determining sleep stages
- EKG (electrocardiogram) for heart rate and rhythm
- Nasal airflow sensor for airflow
- Snore microphone for snoring