Important features

Sleep Score

This is a single number from 0 to 100 indicating the quality of sleep for the night. Number is strongly based on total sleep time, but also the amount of REM and DEEP sleep, and number of estimated awakenings are in the math. This means that the more you sleep, the more you have REM sleep, and the more you have DEEP sleep, and the better your Sleep Score is. Usually values around 80 and higher can be regarded as good.


Disclaimer: The estimation of awakenings is based on movement activity. Quietly Watching TV or reading in bed without moving much is easily interpreted as sleep. Also if user is awake long times at night but not tossing&turning, just trying to fall a sleep, is estimated as being asleep. Therefore the product is not suitable for estimation of actual sleep/awake time and sleep quality in all use cases. 

All three Sleep Stages

EMFIT QS health monitor estimates how much light, deep, and REM sleep you get each night. Sleep is the time when your body gets ready for the day ahead, and when we talk about sleep quality, it’s REM and Deep sleep that get all the attention.

Deep sleep is the time when your body recovers. When the cells repair themselves and your body gets ready for all the physical challenges of a new day.

REM sleep is when your mind recovers, making sure that all the important things you learned, saw, and experienced during the day are stored in a safe place.

What about light sleep? Well, that’s just a lighter stage of sleep that doesn’t do much for you – it’s just there.

Heart Rate Variability (HRV)

Heart rate variability, or the change in time intervals between heart beats, is a broad indicator of your overall health and fitness. 


If your heart beats steadily with intervals of identical length between each pulse, you have low HRV, which is considered “bad.” If your heart beats are of varying length between each pulse, you have high HRV, which is considered “good.”  Years of clinical research has shown that the higher the HRV, the greater your resilience and the lower your stress. The lower the HRV, the lower your resilience and the greater your stress. 

Heart & breathing rates

Emfit QS measures your heart and breathing rates and uses this data along with movement activity data to calculate the sleep classes.

It also measures resting heart rate, which tells about general health. For example, a couple days before getting actual flue symptoms, your resting heart rate will usually rise, letting you know you might want to prepare for some not-so-dashing days ahead.


Resting heart rate may also be used for example as a mild indicator of stress or overtraining.

Recovery data

Total Recovery is simply difference between morning and evening HRV values. Usually it should be positive, indicating that there has been efficient recovery and resting during the night.

Values of Recovery are highly individual, and you should inspect them against your own baseline values, and also in comparison to Evening HRV values.

Autonomic Nervous System Balance

Knowing the balance of the autonomic nervous system is important, because it controls and regulates all the functions necessary to maintain life. This is known as the balance between sympathetic and parasympathetic nervous system, and the balance can be affected by stress, for example.

Movement activity, tossing & turning

EMFIT QS tracks how restless your sleep is based on the amount of movement during sleep. One of our users, Sky Christopherson, World Record holder and founder of OAthlete, uses movement data as an indicator of how hard his athletes’ workouts are; the more restless the sleep, the harder the previous workout has been for the athlete’s body and the lighter the next workout should be.

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