iPhone App: Sleep Cycle

Sleep, for some people, is luxury. When you’re a student, a blog writer, a guitar player in a band and a web designer (yes, me), every minute your eyes are closed is precious.
The student part is especially sleep-depriving: not only do you spend nights learning for tests or writing papers (well, when you’re not on Facebook), but you have to get up the next morning to attend classes. Also, if you’re in a uni where attendance is not compulsory, you’ll just sleep all day and end up jet-lagged and have a hard time recovering.
While certain aspects of sleep may still be a little mysterious to scientists, we know that we go through two main stages during the night. The most important one is REM (Rapid Eye Movement) sleep, during which – you guessed it – the eyes move rapidly, and your dreams are the most memorable. An average adult spends 90–120 minutes of a night’s sleep in the REM stages, which tend to be quite short and interrupted by Non-REM sleep, which are light to deep sleep phases.

As a rule of thumb, the lighter your sleep, the easier your waking will be. Have you ever woken up feeling completely wrecked when the alarm clock goes off, despite the fact that you have slept “enough” hours? When this happens you have probably been awakened during a deep sleep phase, and your whole day can turn into one long zombie marathon.

If only there was a way to monitor your sleep, and to be woken up only during the lightest stages! But oh wait! As it turns out, there is an app for that. Meet Sleep Cycle, the iPhone application that will change your life – it certainly has changed mine.

How does it work?

Sleep Cycle requires you to put your iPhone, face down, on your bed. It will monitor your sleep by sensing your movements, which tend to change according to the sleep stage you’re in thanks to the accelerometer. Before you go to sleep, just select a wake up time margin of ±15 minutes, and the app will wake you up during the lightest sleep phase in that 30 minutes window.
Are you suspicious? Another voodoo, too good to be true app? Another “nude scanner“, “hand warmer” or “air blower” app? That’s what I was thinking, until I tried it.

: Normal sleep

I have been using the app for two weeks now, and it really blew me away. For my first test run, I chose a very ordinary situation: going to sleep at 00AM, waking up at 7AM. With a normal alarm, my chances of being tired at wake up would be about 50/50, because I usually need about 7 hours of sleep, but then again it depends which phase I’m in when the alarm goes off. This time, waking up was extremely smooth. The music started playing (there’s a beautiful selection of sounds available, most of them are very peaceful and relaxing, and some are actually very nice instrumental pieces I’d be interested in listening to outside of the app’s context), and as soon as it was loud enough for me to hear, I woke up, fresh as a daisy. Very good performance of Sleep Cycle so far, but then again it may just have been luck. Thankfully, the app also draws a graph of your sleep for you to inspect upon waking up. This feature alone would be enough for a dedicated app!

: Sleep under influence

For my second night with Sleep Cycle, I decided to go though on the app – and myself. I went to sleep at 1AM again, but decided to wake up at 5AM. Only 4 hours of sleep would normally ruin my day, but how well did Sleep Cycle calculate my wake up time? Pretty well. It wasn’t the most pleasant morning of my life (it was still nighttime, which can have quite a psychological impact), but I wasn’t exhausted, and I was able to get to work normally, after a good breakfast.

After a week with the app, I decided to put it to the ultimate test. After a concert, lots of alcohol and a sleep-deprived night before that, I was truly dead – ready to sleep 15 hours non-stop. In the midst of all the blurriness and craziness, I had a last thought for my beloved TechHaze readers before going to sleep and did not forget to set up Sleep Cycle for a relatively short 8hour sleep. I won’t lie, waking up wasn’t a pleasure, but after all, I did wake up, which is not a given in this kind of situations, and most of the discomfort was due to the hangover, not so much exhaustion.

Verdict

I can’t live without Sleep Cycle anymore. What surprised me most was that the app actually worked as advertised. I don’t know if it’s some kind of placebo effect, but I don’t care, because it works! The UI is well designed, the instructions are clear. There’s even a test screen which will help you find the optimal position in your bed: just lie down, and as soon as you roll-over, the phone should beep. The music that’s shipped with the app is really nice, the app is easy to use and it makes your life easier, what else do you want?
Oh well, a few things. Because the app has to be running, and because the iPhone OS doesn’t support multitasking, you won’t be able to run the iPod app while falling asleep. Sure, there’s a walk-around, but a built-in function would be a nice plus.
Because the app is constantly running, you’ll have to plug your iPhone in all the time, which limits the range of possible locations in your bed because of outlet proximity (or lack thereof). It would be nice if one could choose custom music from the iPhone library to wake up to, or a broader (or more restricted) time window for the wake up time. Oh, and too bad the app doesn’t (officially) support the iPod touch, but this is due to Apple’s limitations.
But from what I’ve read on the developer’s website, some of these features are already being worked on for a future update, which is great.
This app will cost you 0.99$ and now has fixed spot on my iPhone. Bonne nuit.