Sleep cycle between REM and deep sleep, mimicks natural sleep patterns

Starts at 15 Hz and takes you down to a deep sleep at 0.4 HZ, then cycles through stage 2 up to 7 HZ for REM sleep. Overall, cycles down to deep stage 4 sleep twice, down to stage 3 once and stage 2 twice, each time returning to REM sleep. After 7 hours it stays at 7Hz REM sleep indefinitely. This can be used for naps.