 Sleep states could be used to sound a wake-up alarm only when the sleeper was in the light stages of sleep, likely to awake more refreshed.Details of sleep could be uploaded to the MyZeo Web site, where they were stored, with detailed historical charts of sleep patterns downloadable, and email suggestion on improving sleep could be sent.The state of sleep was detected by a headband, essentially comprising three long-lasting electrodes made of electrically conductive fabric and a wireless unit, that transmitted data to a Zeo bedside clock unit or Apple iPhone which displayed data and sounded the wake alarm.