New York: A team of US researchers has found that smartphones are capable of detecting blood oxygen The saturation level drops to 70 percent which is the lowest value a Pulse oximeter Must be able to measure.
Proof of theory research by University of Washington (UW) and University of California San Diego The researchers involved having participants hold their finger over a camera and smartphone flash, which used a deep-learning algorithm to sense blood oxygen levels.
When the team delivered a controlled mixture of nitrogen and oxygen to six subjects to artificially lower their blood oxygen levels, the smartphone correctly predicted whether the subject had low blood oxygen levels 80 percent of the time.
“Other smartphone apps that do this have been developed by asking people to hold their breath. But people feel very uncomfortable and have to breathe after a minute or so, and that’s to represent the full range of their blood-oxygen levels. “There is little to no clinically relevant data,” said co-lead author Jason Hoffman of the University of Washington.
“With our test, we were able to collect 15 minutes of data from each subject. Our data shows that the smartphone can work well in the critical threshold range,” Hoffman said in a study published in Digital Medicine.
Another advantage of measuring blood oxygen levels on a smartphone is that almost everyone has one.
“This way you can do multiple measurements with your own device at either no cost or low cost,” co-author Dr. Added Matthew Thompson, professor of family medicine UW School of Medicine.
This would be really beneficial for telemedicine appointments to be able to quickly determine if patients need to go to the emergency department or if they can continue to rest at home and make an appointment with their primary care provider later.
To collect data to train and test the algorithm, the researchers asked each participant to wear a standard pulse oximeter on one finger and then place the other finger on the same hand over the smartphone’s camera and flash.
The researchers used the participants’ data to train a deep learning algorithm to infer blood oxygen levels. The rest of the data was used to validate the method and then tested to see how well it performed on new subjects.
“The camera records how much the blood absorbs light from the flash in each of the three color channels it measures: red, green and blue,” said senior author Edward Wang, assistant professor at UC San Diego.
The team hopes to continue this research by testing the algorithm on more people.
