As the “quantified self” movement/phenomenon rolls forward, I thought it was appropriate to talk about a few different ways to measure sleep. This isn’t an all-inclusive list, but it covers the major “technologies” involved – so if there’s something not talked about here, it will more than likely fall into one of these major categories.
When we talk about measuring sleep, I think we can group these devices into three major categories:
- Brainwave monitors that behave like an EEG
- Accelerometer based Smartphone apps
- Accelerometer based personal fitness devices
If you’ve read much on this blog, you’ll know that I’m a big fan of the Zeo Sleep Management System. It’s basically a single channel EEG that monitors your brainwaves during sleep by using a headband that you wear overnight. I’ve got a much more detailed review of the Zeo here, so I’ll not repeat it.
Zeo is like having part of a sleep lab in your bedroom. It won’t monitor your respiration or pulse, but it will tell you (with incredible detail) what stage of sleep you were in at a specific time.
The Zeo Mobile version that I have uses the headband teamed up with an app for your Smartphone. It costs about $100.
Accelerometer Smartphone Apps
These are widely available for any Smartphone with an internal accelerometer (which is most of them these days). They all work pretty much the same way:
- They rely on a Smartphone app you download from the appropriate app store – usually between $0.00 and $1.99.
- You plug in the Smartphone so it stays on and charged all night.
- After turning on the app, which turns on the sensitive accelerometer in the phone, you place the Smartphone on the bed – normally beside your pillow (where it can detect motion but not interfere with your sleep).
- When the phone detects motion with the accelerometer (it will require some time to calibrate), it will correlate it with the likely sleep state you are in (you move different amounts based on the sleep state), and display it on the phone.
I’ve used apps for the Andoid and iPhone platforms, and they perform similarly. They are nowhere near as accurate as the brainwave measurement method, but good enough to activate an alarm when you’re in a lighter stage of sleep (and that’s the primary intent). Oh, they cost less than a cup of coffee.
A few of the Smartphone apps are:
Accelerometer Fitness Devices
This last category covers the newer “wearable” devices. They work by embedding an accelerometer in a device that you wear – clip on to a piece of clothing (FitBit Ultra) or wrap around your wrist (Jawbone Up). Both of these cost $100 as well.
These products are more accurate than the Smartphone based apps, but less than the brainwave devices. They still rely on detecting motion, but not in the “motion of the bed” as the previous apps do, but rather the actual motion of your body.
However, if you are wide awake and perfectly still, these will believe you are sound asleep.
Note that monitoring sleep is just one of several uses for the fitness tracking devices – they can also measure your activity during the day, so they are much more multipurpose than just at nighttime.
In short, the price point of all these devices is from free (or almost free) to $100.00 – with nothing in between. Their accuracy and utility correlates pretty well with their price. You get basic sleep information with the Smartphone apps, incredible accuracy with the Zeo, and more utility but middle-of-the-road accuracy with FitBit and Jawbone.
All of them will give you some major insight into your life … at least the third of it where you’re asleep.