A phone camera flash can measure oxygen in the blood by up to 70% at home


A team of American researchers has discovered that smartphones are able to detect oxygen saturation levels in the blood by up to 70%, which is the lowest value that a pulse oximeter should be able to measure, by recording how much blood absorbs light from the flash in each of the colored channels. The three it measures: red, green, and blue, according to the newspaper Washington.

The proof-of-principle research by researchers from the University of Washington and the University of California, San Diego, involved participants placing their fingers on a camera and smartphone flash, which uses a deep learning algorithm to decode oxygen levels in the blood.

When the team administered a controlled mixture of nitrogen and oxygen to six people to artificially lower blood oxygen levels, the smartphone correctly predicted whether the person had low blood oxygen levels 80 percent of the time.

Other smartphone apps have been developed that do this by asking people to hold their breath, but people feel very uncomfortable and have to breathe after a minute or so, before their blood oxygen levels drop enough to represent the full range of data.

Lead author Jason Hoffman, co-author of the study published in Digital Medicine, said:npjFrom the University of Washington: “With our testing, we are able to collect 15 minutes of data from each subject, as our data shows that smartphones can perform well under critical conditions.”

Co-author Dr Matthew Thompson, professor of family medicine at the University of Washington School of Medicine, added: ‘This way you can get multiple measurements using your own device either at no cost or at low cost, and this will be useful for remote doctor appointments to be able to determine if patients need To go to the emergency department quickly or whether they can continue to rest at home and make an appointment with their primary care provider at a later time.

The researchers used data from participants to train a deep-learning algorithm to pull oxygen levels in the blood. The rest of the data was used to validate the method and then test it to see how well it performed on the 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 lead author Edward Wang, associate professor at the University of California, San Diego.

Scroll to Top