Does the app know if I am awake?
In general, actigraphy is not powerful enough to distinguish you being awake in the bed and not moving from being out of bed for toilet. This means that it is not able to tell how long it takes you to fall asleep. It also gets confused when you go to toilet in the night. However, we have developed an experimental way of overcoming this deficit.
a) Awake detection
Enable awake detection in Settings > Sleep tracking > Awake detection.
Awake detection estimates the length of the awake phase in two ways:
- By comparing the length of the first light phase of your sleep with a standard, we can estimate how long it took you to fall asleep
- By considering unusual positions of your device, we can find time points in which You were awake and estimate from there. This works as an automatic pause.
b) Without using awake detection
In this case we need a little help from you to correct your sleep tracking data. Use the sleep tracking pause feature whenever you are tracking but not sleeping.
Pause is available from sleep tracking screen using the Pause button. This will display the pausing dialog with the pause time left. Pausing is designed to finish without your further interaction. You may add +5 minutes anytime.
You can add pause time without looking at the touch screen. This feature needs to be enabled in Settings > Sleep tracking > Volume and camera button effect. This allows to cap pausing at minimally 5 minutes every time your press the volume of camera buttons. If your device is tracking with screen on (see the next section for details), no other action is required. If your device tracks with screen off the sequence to cap pausing is to press the power button and than one of the volume buttons or camera button.
In case you already know your typical fall asleep sequence you can configure automatic pause time at sleep tracking start. This option is available in Settings > Sleep tracking > Delayed sleep tracking.
You can also edit your sleep graph ex-post in order to correct your wake up or before fall asleep periods. This can be done in the sleep graph detail screen. Graph detail screen is displayed, when you click on a graph on the screen that lists all your recordings. You can select the related portion of the sleep graph and choose MENU > Delete selected
Using heart rates for awake detection
In contrast to manual techniques or estimates, using a heart rate sensor gives us an exact information about your awake times.
During sleep, your heart beats up to 10 BPM slower than when awake. Heart rate tracking together with actigraphy gives a solid overall picture about your sleep.
- actigraphy recognizes between light and deep sleep phases
- heart rates help to identify awake and asleep states
We always take a 5 minute average HR values to check your awake state. This means mainly two things:
- We cannot measure awake states shorter than 5 minutes
- You do not need to supply your resting heart rate since we infer that from your sleep values
Sleep as Android supports most Bluetooth heart rate devices via BLE, and various smartwatches sensor. Please refer to Wearable
for more details.
Using light level for awake detection
Sleep as Android uses the ambient light sensor (lux sensor) that is present in nearly every smartphone to measure the level of ambient light in your bedroom.
How to enable
Settings > Sleep tracking > Awake detection
What does it do
When awake detection is enabled, light is being measured during sleep tracking.
- You will see light level plotted on your sleep graph (in the same way as heart rates or breath is plotted), in lux units.
- #dark / #light tags will be added to your sleep records.
- If there is disturbing light (more than 30 lux) after sunset, we consider it as an Awake period.
The #dark tag is added when you have less than 30 lux for at least 90% of the night.
The #light tag is added when you have more than 60 lux for at least 33% of the night.
Light measurement also plays a role in automatic sleep tracking.