Updated February 8 A pulse oximeter measures blood oxygen levels and is one of the key ways to determine how serious someone's case of COVID-19 is. But it's not always a racially equitable device. It can produce inaccurate results for people with darker skin tones. And we know that thanks to an Oregonian. THE FINDING: Michael Sjoding, a pulmonary physician and professor based in Michigan and originally from Salem, Ore., conducted a study on the device, which was published in December. His findings were first noted by the Salem Reporter. The results, which analyzed white and Black ICU patients, revealed that compared to white patients, Black patients had hidden and dangerously low oxygen levels in their blood not detected by a pulse oximetry device at nearly three times the rate of white patients.