Zeo Sleep Tracking

Sleep Tracking

The Zeo is a small headband that contains a single-channel EEG. The company produced two major versions: a Bedside model (photo left) with integrated alarm clock, and a Mobile version that connects to phones over Bluetooth.

The accuracy of the readings is fairly high, at 75%1 – 81%. The device displays readings as hypnograms and categorize each sleep stage. As a result, this facilitates data interpretation. The measuring process starts when you remove the device from the charger, and stops as soon as you place it back.

Zeo Bedside

This is an earlier product. The headband communicates exclusively with the clock, so no phone connectivity. The last sleep is shown on the screen in front, together with the “ZQ” score.

The device saves all sleep history to the SD card. You can retrieve all sleep logs on the device. 
It’s also possible to view the data on a PC, by using the SD card.
The PC displays a higher data resolution than on screen. 

The Zeo Bedside consists of several components:

  1. Alarm clock unit
  2. EEG module
  3. Sensor headband
  4. Power adapter
  5. (optional) replacement sensor headband
  6. Generic SD card
  7. Generic SD card reader

Zeo Mobile/Zeo Pro

The Zeo Mobile is the second product that came out and is the most popular. However, there are no significant differences between the Zeo Mobile and the Zeo Pro. At this time, it is only possible to use the Android app, or sideload it on iOS. The device consists of a charging dock, a charger (5v mini-USB), the Zeo main unit and a headband/sensor pad.

The phone connects over Bluetooth and is used to collect and view the data. In case of connection loss, the Zeo can save one night of sleep on the device itself. Pressing the button reconnects the Zeo to the device and another press will upload the saved data. In the app, you can view the hypnogram and the ZQ. In a notification bar, you can see your current night’s progress.

The original Zeo app is a bit outdated and limited; especially, the sharing functions do not work accurately anymore. For this reason it is highly recommended to also get the “Zeo Companion app” (APK link) which gives a more precise hypnogram in 30-second intervals. By using the share function, it is possible to export images like this:

 

The Zeo Pro consists of the following components:

  1. Charging dock
  2. EEG module
  3. Sensor headband
  4. Power adapter
  5. (optional) Replacement sensor headband
  6. (not shown: Android device with app)

Quirks

Due to the similarity in EEG signals of NREM1 and REM, it is relatively common that at the start of a sleep block, there is some mislabeled REM sleep. If you look at the hypnogram, it looks like this:

Because of this, the Zeo has a tendency to slightly overestimate the amount of REM sleep.

Tips

The original recommendation of Zeo to replace the headband every few months has gotten difficult and expensive, due to the limited replacement availability. However, there are certain things that you can improve the lifespan:

  • Clean your forehead before use
  • Occasionally clean the sensor pad with alcohol
  • Sometimes, if readings are bad, the headband is just too loose.

The headbands are NOT compatible between versions. This is because they have a different snap layout. Make sure you are getting the right one if you buy them separate.

It is possible to make DIY replacement headbands
There are also headbands available on eBay. They have different styles and are supposed to last indefinitely for $60 (+ shipping). However, these have not yet been evaluated.

Using the Zeo Bedside, it is possible to get a raw output signal by connecting it with a serial cable. http://www.sleepstreamonline.com/rdl/starting.html. We are currently investigating this.

How to purchase

Because the Zeo goes bankrupt in 2013, they are only available second-hand. On eBay, they are generally available between $50-80, depending on condition and integrity. You may also be able to find a great deal at a more local platform, so check the Facebook marketplace and other local options.

In the Discord, there is the option to get the Marketplace tag; this way you will be tagged if a new deal is available.

New headbands are in small silver packets; if any of those are included, that is a huge plus and worth investing a bit more. This is because it is the main lifespan-limiter.

If you find a Zeo, make sure to get the first 4 components from the above lists! Depending on where you get your Zeo from, the power plug may not match your local outlets. The supplied plugs work on all voltages, but you may require a travel adapter. Alternatively, the Zeo Bedside works on a 5v 500mA adapter with a 5.5mm diameter round plug with 10mm in length. The Zeo Mobile/Pro works on any Mini USB cable connected to a power source. Therefore, if you find a deal without a charger, do not be disappointed.

Android applications:
– Zeo sleep manager
– Zeo Companion app

Main author: Jelte1234

Page last updated: 11 April 2020

1.
Shambroom J, Fábregas S, Johnstone J. Validation of an automated wireless system to monitor sleep in healthy adults. J Sleep Res. 2012;21(2):221-230. [PubMed]