How Do Sleep Trackers Work? Everything You Wanted To Know About

How Do Sleep Trackers Work

With so many doctors recommending us to have a good night’s sleep. It is becoming a necessity for one to measure the quality and quantity of sleep to beat the threshold.

Many devices come up every year, claiming to assist you track your sleep patterns. The question is that bugs many is that, how accurate is this data. Is there is any chance that is this data is reliable to make the correct judgment and improve the quality of sleep.

I have scoured the studies and the internet to give you a comprehensive answer to your question. Here are the thoughts and opinions of medical experts and research gurus.

A Deep Dive into the Sleep Tracking Technology

Sophisticated software and devices have been developed to monitor sleep patterns. To understand these patterns, let me walk you through basic concepts.


An actigraphy is an invasive way of measuring movement. The basis of this concept comes from the fact that when you sleep, you don't make any movement. You're at rest.

Personally, I will have to agree that it is a smart way of looking at sleep patterns but it has certain limitations. One being that, you can sit for two hours watching television in a stationery position and the device will measure that you're asleep. Which is not effective according to some experts.

In other words, actigraphy measures only one single metric, movement.


This device uses MEMS technology( Micro-Electric-Mechanical Systems), the tiny components act as sensors in actigraphy. Their role is to measure the quantity and quality of sleep. The accelerometer is found in most sports and fitness tracking devices.


It is the traditional ways of measuring sleep patterns. This procedure involves a person going to the lab and over 20 wires are attached to the person's head while they're asleep.

Polysomnography measures breathing rate, heart rate, eye movement. Some experts vouch for the Polysomnograghy over actigraphy. However, many still disagree with it, because when a person is in the lab, they can't have a good night sleep. And that makes the polysomnography not a good indicator of measuring sleep quality.

Research and Studies

Hakim and Martin published a report in 2011, the research was to determine the usefulness and accuracy of the actigraphy. They looked at the following factors in their assessments:

  •  Daily sleep diaries.
  • Clinical interviews and sleep questions.
  • Laboratory polysomnography (PSG)
  • Videosomnography in charts.

Both of these two researchers concluded that an actigraphy is useful in the assessment of sleep in the natural environment. In other words, you can get an accurate data from actigraphy if you have a normal sleep pattern.

A normal pattern of sleep is where you sleep without making considerable movements. From the research, you can't measure the quality or quantity of sleep using an actigraphy, if you have sleep disorders.

You can only use to estimate information, where you can get the accurate data on the total time your sleep, sleep percentage and how after sleep waking occurs.

Another interesting quote comes from Michael Scullin, from Emma University School of Medicine's Department of Neurology:

" Consumers should not expect that these devices will be able to distinguish between sleep because this devices rely on the movement, when sleep stages are defined primary by the brain activity."

From these three researches, it is true that waking time is tricky for the actigraphy to measure, because periods of no movements can be registered as sleep.

What about polysomnography?

Polysomnography gives accurate data on the measurement of sleep patterns. You can get accurate data from this device if you have sleep disorders.

In other words, people can't use polysomnography if they have healthy patterns of sleep. That's because when they go to the lab they won't sleep well. It is difficult to sleep when you have over 20 wires on your head get information from you.


It's not that easy to judge how sleep trackers operate, and even how they work, whether you sleep in a bed, couch or recliner. Actigraphy works when they measure the total amount of time spent when one is sleeping.

There is little independent scientific research test on those devices. You can't fully trust them to give you accurate information. What you can do with sleep trackers is to have a realistic expectation into what they can do.

Even if researchers decided to test different sleep trackers, by the time they have published the results, new devices would be in the market.


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