Experimental Pulse Oximeter Accurate Regardless Of Skin Tone, Researchers Say

August 12, 2026
Dennis Thompson HealthDay Reporter

Pulse oximeters became widely known during the COVID-19 pandemic, as doctors used the finger clip devices to tell whether a respiratory infection was robbing patients of needed oxygen.

But skin tone impairs the effectiveness of pulse oximeters, causing them to overestimate blood oxygen levels of darker-toned people.

That’s no longer a problem with a new type of pulse oximeter, researchers at Tufts University say.

The new device can accurately read blood oxygen levels regardless of skin tone, age or other factors that can interfere with their readings, researchers said.

Testing has shown that the new device — called ChromaSense — has accuracy within 1.4% to 2.9% of standard oximeters, researchers said.

Traditional pulse oximeters “read” blood oxygen levels using red and infrared light. Oxygen-rich blood absorbs those colors differently from oxygen-poor blood.

The problem is that light doesn’t pass through darker skin the same way as it does through lighter skin. Melanin, a pigment in the skin, absorbs and scatters light, and for people with darker skin the level of extra absorption can interfere with accurate readings.

The new device, called ChromaSense, also uses light, but it first measures a person’s skin tone and then adjusts its light level and analysis to match the patient.

“If you train a model that converts light signals to blood oxygen, pulse or pressure and you don’t ensure that the dataset that you’re training with is diverse enough in terms of age, race and gender, it can affect the performance or accuracy of the model,” researcher Valencia Koomson said in a news release. She’s an associate professor of electrical and computer engineering at Tufts in Medford, Massachusetts.

As many as 17% of Black patients can have dangerously low blood oxygen levels that are missed by traditional pulse oximeters, a rate of misdiagnosis three times that of white patients, according to a 2020 New England Journal of Medicine study cited by the research team.

“An apparently high-performing model can look far less impressive once broken down into specific groups,” Koomson said.

The ChromaSense device uses a watch-sized box attached to the wrist that measures reflected light from skin and tissue, as opposed to only measuring light transmitted through a finger.

Researchers are working to hone the device so that it can also detect blood pressure.

Tests on more than 2,300 adult ICU patients showed accuracy up to 90% for blood pressure readings, researchers said.

“The blood-pressure work is not yet built into ChromaSense, but the goal is in the future to embed that machine learning model into the device,” Koomson said.

More information

The National Council on Aging has more on testing oxygen levels at home.

SOURCE: Tufts University, news release, Aug. 7, 2026

Medical Technology: Misc.