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- The FDA proposes new guidelines for blood oxygen monitors to improve accuracy across skin tones.
- Manufacturers should test devices on a diverse group using the Monk Skin Tone Scale.
WASHINGTON — The U.S. health regulator on Monday proposed new guidelines for widely-used blood oxygen monitoring devices to improve their performance across skin tones amid growing evidence that the current ones are not reliable for patients with darker skin.
Pulse oximeters clip onto a fingertip and pass red and infrared light through the skin to gauge oxygen levels in the blood. Doctors have long known that pulse oximeters are less accurate in estimating blood oxygen levels in non-white patients.
The discrepancies were considered insignificant until the COVID-19 pandemic, which exposed some of the risks associated with these flaws.
In its draft guidance, the U.S. Food and Drug Administration recommends that manufacturers gather data from a "diversely pigmented group of 150 or more healthy participants" to test device performance.
All participants should also be evaluated on a 10-skin tone scale called the Monk Skin Tone Scale, with at least 25% falling into each of the 10 groups.
Previous rules required pulse oximeters to be tested on a minimum of just 10 subjects, only two of whom must be "darkly-pigmented."
Leo Anthony Celi, principal research scientist at the Massachusetts Institute of Technology, said this was a "step in the right direction," but the testing of devices on healthy individuals could be problematic.
"We're using this (device) for patients in the intensive care unit, patients who are undergoing surgery," he said.
The proposed guidance, if finalized, would apply to devices used for medical purposes and not to those sold directly to consumers in stores or online that are not approved by the FDA.
The agency said it expects some already approved devices may meet the updated criteria without significant hardware or software changes.
Pulse oximeter manufacturer Medtronic said "it was deeply committed to achieving equitable care for all patients," and was using the Monk Skin Tone Scale in one of its studies.
