The U.S. Food and Drug Administration is currently working on improving pulse oximeters to reduce the device’s built-in racial bias against people with darker skin tones.
In a draft guidance released earlier this year, the FDA called for manufacturers to expand the skin tone varieties when tests are done on how well the devices work. The unit is calling for increased testing to show that the pulse oximeters work well on everyone for all skin pigments.
Through their draft guidance, the FDA provided a series of recommendations for clinical testing. The recommendations included having “a diversely pigmented group of 150 or more healthy participants” in early testing phases and having at least 25% of the study group fall within each skin color group included in the Monk Skin Tone scale.
Another recommendation included being transparent about the racial bias in the devices and appropriately labeling the pulse oximeters with a warning that skin tone can cause differences in the device’s performance.
“This draft guidance is aligned with the FDA’s broader commitment to helping facilitate the development of high-quality, safe, and effective medical devices,” said the director of the FDA’s Center for Devices and Radiological Health, Michelle Tarver, M.D., Ph.D. per the FDA’s official announcement. “Our draft recommendations are based on the best available science to help address concerns of disparate performance of pulse oximeters based on an individual’s skin pigmentation.”
The bias in pulse oximeters has long been detected, yet nothing has been done to address the issues. In a 1990 paper, researchers first reported that the device overestimated the oxygen saturation in Black patients more than any other demographic. The report was further backed by a 2005 study and a 2007 study that reaffirmed that pulse oximeters tended to overestimate oxygen levels in people with darker skin tones.
Thank you @JulianGloverTV @ABC news for having me on to discuss the travesty of the pulse ox device. Pulse oximeters have been shown to overestimate oxygen levels in those with darker skin, leading to denial of oxygen, an ambulance ride, hospital admission, and treatment. pic.twitter.com/BIwazpZVZL
— Noha Aboelata, MD (@NohaAboelataMD) January 19, 2023
Although researchers attempted to draw attention to the racial disparities in the device, attention shifted to the issue during the COVID-19 pandemic. The pandemic brought forth new focus on disparities in health care, drawing attention to pulse oximeters as they were used increasingly to determine the effects of the virus.
First created in the 1970s in Japan, pulse oximeters are clamps that are attached to fingers and toes to measure oxygen saturation and detect respiratory issues. The device uses light to measure saturation, sourcing red light to measure how much of it is absorbed by the finger.
The more light is absorbed, the higher the oxygen level in the blood. A rate of 100% indicates that the oxygen saturation is normal, while those below 90% indicate there’s an issue.
With darker skin tones, the devices tend to make errors in their readings as they usually read them as normal when they can be dangerously low, leading to undiagnosed respiratory issues.
