How do smartwatches track sleep?
As you know, nowadays smartwatches are on-trend. As a result, many smartwatch brands are introducing different types of advanced features day by day. According to the brands’ claims, smartwatches can track sleep, heart rate, measure blood pressure, etc.
In this article, I will specifically discuss the feature of sleep tracking. I will discuss how do smartwatches track sleep and what technology they use for monitoring sleep. Furthermore, I will also discuss if their results are even accurate? And can we rely entirely on their results?
This article aims to give you a brief overview of how watches track sleep, so I will not go into too much depth. So I’m going to cover the following points.
- What technology do Smartwatches use for tracking sleep?
- Are the results accurate?
- Can we rely entirely on their results?
- What technology do Smartwatches use for tracking sleep?
- Are the results accurate? How sensitive are these sensors?
- Can you rely entirely on their result?
What technology do Smartwatches use for tracking sleep?
The process of how smartwatches track sleep is very simple. They only need the combination of three things:
1) A motion sensor: The motion sensor in the smartwatch is used to detect movement. The watch will monitor any movement that you make during your sleep time. If it detects that you are restless, it will send that data to the app.
2) PPG (Photoplethysmogram): This is a type of sensor which uses light to detect how much blood is flowing through your body.
3) Galvanic Skin Response (GSR): This sensor detects electrical impulses in your skin which can be used to measure your stress level.
Now Let me explain the last two a little more.
How PPG (Photoplethysmogram) helps in Monitoring sleep in smartwatches?
Smartwatches use PPG (Photoplethysmogram) to determine how much blood flows through your wrist. The monitor checks your body’s light absorbance levels. When you are awake or active, there is more blood flow and light absorbance in your skin. But when you fall asleep, there is less blood flow and light absorbance in your skin.
How Galvanic Skin Response (GSR) helps in Monitoring sleep in smartwatches?
Galvanic Skin Response (GSR) sensors measure your skin conductance. This is the ability of your sweat glands to react to stimuli such as changes in the environment, stress level, and excitement. If you are stressed or excited, your skin will become more active, and the sensor will pick up these electrical impulses. So if the watch measures a high level of activity, it can assume you’re awake. And if the watch measures a low level of activity, it can assume you’re asleep.
The sensors I mentioned above are embedded in the watch so that they can constantly monitor your sleep.
Where are these sensors located in the watch?
The motion sensor is usually located at the back of the watch, while the PPG and GSR sensors are located on the side of the watch near your thumb. So as long as your wrist is touching the mattress, these sensors will be able to monitor your sleep.
How do you access the data given by these sensors?
The data collected by the sensors is then processed and analyzed by an app on your smartphone. The app will show you a detailed breakdown of your sleep, including how much time you spent in deep sleep, light sleep, and REM sleep. It will also show you how many times you woke up during the night.
Are the results accurate? How sensitive are these sensors?
As I mentioned above, smartwatches track sleep by utilizing motion sensors, PPG (Photoplethysmogram) and GSR. But due to some reasons, the data won’t be 100% accurate.
For instance, it won’t pick up any movement if your watch is not touching the mattress. So if you happen to move around in your sleep, the watch might not pick up that movement. Also, if you toss and turn a lot during the night, the data collected by the motion sensor will be inaccurate. And finally, if you are stressed or excited before bed, your skin conductance level will be high and the GSR sensor will pick that up. So the data collected by the GSR sensor might not be accurate.
But overall, the data collected by these sensors is still very reliable and can give you a good idea about your sleep habits. And if you’re not happy with the results, you can constantly adjust the settings on your app to get a more accurate reading.
Can you rely entirely on their result?
You can’t wholly rely on the results because of the inaccuracy issues I mentioned above. If you have a severe problem with your sleep, you should consult a doctor or medical professional instead of a smartwatch. A doctor will give you a more accurate diagnosis and might be able to help you with your sleep problems. But if you don’t have any significant issues and just want to track your sleep to manage it better, then a smartwatch can give you a pretty accurate reading which you can rely on.
However, keep in mind that you also need to maintain a healthy lifestyle when using these devices for tracking sleep. For instance, your diet and exercise can significantly impact the quality of your sleep. So if you want to get accurate results from these devices, you should maintain healthy habits as well.
So now you know how smartwatches track sleep. They use motion sensors, PPG sensors, and GSR sensors to monitor your sleep. The data collected by these sensors is processed and analyzed by an app on your smartphone. The app will give you a detailed breakdown of your sleep, including how much time you spent in deep sleep, light sleep and REM sleep. The results you get from these devices aren’t 100% accurate, but they’re still reliable and can give you a good idea about your sleep habits. But if you have severe problems with your sleep, I would recommend consulting a doctor instead.