When we breathe in, oxygen enters our lungs, and it is then transferred to our red blood cells for distribution throughout our bodies. Since, our bodies require a lot of oxygen to function, healthy individuals constantly have an oxygen saturation level of at least 95%.
Ailments like COVID-19 and asthma make it more difficult for humans to absorb oxygen from the lungs. As a result, oxygen saturation levels fall to 90% or lower, signaling the need for medical intervention.
Doctors use pulse oximeters, the clips you put over your fingertip or ear, to check oxygen saturation in a clinic. However, patients might benefit from routinely checking their oxygen saturation at home to keep a watch on symptoms like COVID.
Considering that everyone has a smartphone today. And smartphones already have several cool health-related features. In addition to tracking your steps and sleep, your smartphone can also measure your pulse and respiration.
Now, a team of researchers from the University of Washington wants to expand that toolkit by measuring blood oxygen levels.
Researchers developed an algorithm that could estimate blood oxygen saturation to the same level as over-the-counter pulse oximeters permitted by the FDA.
The most recent achievement overcomes two significant obstacles. First of all, this technique does not need the user to hold their breath.
The new computational method created by scientists can reach the same baseline level as medical-grade pulse oximeters. Especially in contrast to earlier smartphone-based SpO2 monitoring methods, which could only measure a floor of 85%.
The method used here is not all that dissimilar from what SpO2 sensors in smartwatches like the Samsung Galaxy Watch 5 and Apple Watch Series 8 do.
The rate of light absorption varies as the flash illuminates the blood’s journey through the arteries. These fluctuations are then analyzed by a customized algorithm to determine the blood’s oxygen saturation level.
Future of phone-based health monitoring
The accessibility of smartphones as a tool for testing blood oxygen saturation levels is one of their largest benefits. Additionally, the technique does not require any special gear or an elaborate multi-camera setup.
It only requires a camera sensor and an LED flash at the back.
Furthermore, it is much simpler to communicate the SpO2 data from a smartphone to a medical professional. Rather than it is to take the reading on a smartwatch, couple it with the phone using a companion software, sync the data, and then transfer it.
These days, monitoring SpO2 levels is crucial because COVID-19 is wreaking havoc on our planet.
To allow other interested parties to build upon it, the team has made the complete dataset available for use. This is essential once more since there were only six human participants in the study, and only one of them had African ancestry. Of them, five were Caucasians.
To fine-tune the underlying system and make smartphone-based SpO2 measurements more egalitarian and accurate, greater diversity and a larger volunteer network are needed. Smartwatches like the Apple Watch have already demonstrated mistake proneness with non-white participants, people with tattoos, and people with fat body types.