Bio-alarm Clocks: The New Wake-up Call
Study of the sleep cycle in humans has led to the invention of bio-alarm clocks. This innovative devices track the different rhythms of your body as you pass through different stages of your sleep and then wake you at the best time – so that you do not feel sleepy on waking up. To know how bio-alarms clocks work, you have to first understand the human sleep cycle. Our sleep can be divided into three broad stages – the waking stage, the non-REM (Rapid Eye Movement) sleep, and REM sleep.
The waking stage is the initial stage when we feel drowsy, our muscles relax, and our eyes become droopy. Once we fall asleep, we enter the non-REM sleep stage first. This is the dreamless portion of our sleep when we gradually go from a light, superficial sleep to a deep, slow-wave sleep – this change can be further divided into four different stages. After the non-REM sleep stage, we enter the REM stage where we have dreams and intense Rapid Eye Movement.
Following this, we cycle between the four stages of non-REM sleep and the REM stage for the rest of the night. Each stage has a characteristic muscle rhythm that can be detected by electrodes. Although the first cycle is of 90-110 minute duration, subsequent cycles last longer than this.
The fundamental principle on which bio-alarm clocks operate is to detect the body rhythms with electrodes and then set off the alarm at the end of a cycle of sleep. Considering that sleep cycles normally last for 90 -110 minutes, these devices have a 30-minute margin of error approximately.
A wide variety of bio-alarms is available. While some bio-alarm clocks (such as Sleeptracker and aXbo Sleep Phase Alarm Clock) are designed like watches so that you wear them on your wrist, others (such as SleepSmart) are designed as headbands. The former detect body movements from your pulse and track your sleep cycles, while the latter detect brainwaves directly. Whatever be the model, these alarms are redefining the way we sleep – and the way we wake up.