Sleep Medicine

Sleep Architecture & Hypnogram

Generate sleep hypnograms with realistic NREM-REM cycling. Explore normal sleep, narcolepsy, OSA, depression, insomnia, and REM sleep behavior disorder.

Clinical Presets

Healthy 25-year-old: efficient sleep, good SWS, normal REM latency (~90 min)

SWS predominates in the first third of the night
REM periods lengthen toward morning
4-5 complete NREM-REM cycles expected

Recording Time (hours)Sleep Onset Latency (min)REM Latency (min)Slow-Wave Sleep FractionREM FractionSleep EfficiencyAwakeningsCycle Length (min)Random Seed

Hypnogram

Sleep stages over time

Sleep metrics

Total sleep

7.0h

Efficiency

87%

REM latency

168 min

Cycles

WASO

47 min

Stage distribution

Select a stage for EEG details

Normal sleep architecture

Normal adult sleep cycles through NREM (N1→N2→N3) and REM in ~90-minute cycles, 4-5 per night.
SWS (N3) predominates in the first third of the night — this is when growth hormone peaks.
REM periods lengthen across the night — the longest REM period is typically just before waking.
N2 comprises ~50% of total sleep time, N3 ~20%, REM ~22%, N1 ~5%.
Sleep efficiency >85% is considered normal. SOL <30 min is normal.

What to notice

Total sleep time: 418 min (7.0 hours).
Sleep efficiency: 87% (normal).
REM latency: 168 min (prolonged).
3 NREM-REM cycles detected.
WASO: 47 min (elevated — sleep fragmentation).

Clinical correlates

Short REM latency (<15 min): narcolepsy (SOREMPs), depression, medication withdrawal
Reduced SWS: aging (normal), depression, OSA, fibromyalgia, chronic pain
Increased awakenings: OSA, PLMS, pain, anxiety, environmental factors
Low sleep efficiency: insomnia (psychophysiologic, paradoxical), poor sleep hygiene
REM without atonia: REM sleep behavior disorder → alpha-synucleinopathy prodrome