In 2020, as COVID-19 hit the world, one aspect of our body became the buzzword- blood oxygen saturation. Just like people would monitor their blood pressure, pulse, or temperature, they were suddenly keen on monitoring the blood oxygen levels aka SpO2 levels. This was because a low SpO2 was a warning sign for someone infected with COVID-19.
A number of fitness bands and smartwatches are, therefore, already offering SpO2 monitoring now. Like the Apple Watch Series 6, for example. But the feature is still mostly limited to extremely pricey gadgets. Exception? The just-launched OnePlus Band which, despite its low price of Rs 2499, comes with an SpO2 monitor.
So, what is this SpO2 monitor and what does it do?
SpO2: How it is calculated
The modern-day smart band or watch is more than just a tool to track your steps or, for that matter, push notifications to your wrist. Like other bands, the OnePlus Band too comes with a collection of fitness trackers and sensors, one of which is the SpO2 monitor.
This, as a sensor, is growing quite swiftly in popularity, with an increasing number of users demanding the same on their fitness trackers. Apart from standalone medical pieces of equipment, SpO2 monitors till now have mostly been seen on smartwatches. That is, until now.
While there are a few ways of testing oxygen levels in the blood, on the OnePlus Band, we have the most common of implementations -- the use of a red infrared light emitted from different LEDs placed on the underside of the central console to calculate if the user's blood has enough oxygen in it.
The band then calculates the level of absorption of the infrared light to figure out the percentage of oxygenation of the user's blood. If the level of oxygenation in the blood of a user is high, it will absorb more infrared light, while deoxygenated blood will allow more of it to be passed through. While not exactly the most sophisticated of methods, this is definitely one of the easiest non-invasive ways of checking blood oxygen levels.
SpO2: Why it is needed
As we mentioned above, SpO2 tracking on smart wearables isn't necessarily the most accurate or sophisticated way of gathering information about how oxygenated your blood is. However, it is still the easiest way of knowing if your blood oxygen levels are dropping.
For a healthy adult, the blood oxygen levels should be around 95 per cent, with numbers dipping down to 90 per cent and slightly below also acceptable during sleep. But lower levels of SpO2 can lead to issues such as fatigue, light-headedness, numbness, and nausea among other serious complications, and can hint at underlying health issues. During infections with COVID-19, dipping levels of SpO2 can indicate a severe infection that requires immediate medical attention.
In other words, it is good to have a SpO2 monitor handy, even if the reliability of such a sensor in a fitness band may not be 100 per cent accurate all the time.
SpO2 tracking: How it works
One of the most important usages of SpO2 tracking is when you're exercising or when you're in high altitude areas. While we did not get the chance to test the OnePlus Band's SpO2 feature in a high-altitude area, we did get the chance to test it out while exercising. The SpO2 tracker on the device can be invoked on command which helps give you an idea if you need to take a break from your workout regime. For us, the tracker showed above 90 per cent saturation of oxygen in between a session of a light workout which included few short sprints and basic exercising.
How useful one will find the SpO2 data is going to differ from user to user. But the fact that such a sensor is now available in an affordable fitness band like the OnePlus Band is going to give consumers some choice. It is also worth noting that the OnePlus Band gets the software and functionality of the SpO2 monitor mostly right.
The sensor in the OnePlus Band not only shows the blood oxygen level but can also tell the user what sort of sleep they are getting, thereby again helping them figure out potential health issues. In the case of the OnePlus Band, the data collected from the heart-rate monitor can automatically be used in tandem with the data collected from the SpO2 sensor, and then later used by the OnePlus Health app to give the user a detailed report on how well they are sleeping, and if they need to see a doctor. Kinda neat, no?