New Pulse Oximeter Reads Oxygen Regardless of Skin Tone

Traditional pulse oximeters, commonly used during the COVID-19 pandemic to gauge blood oxygen levels, have a critical flaw: their accuracy is compromised by skin tone. These devices, which use red and infrared light to measure oxygen saturation, often overestimate oxygen levels in individuals with darker skin due to melanin's effect on light absorption. This can lead to dangerous missed diagnoses, with as many as 17% of Black patients having their low blood oxygen levels underestimated, a rate three times higher than white patients, according to a 2020 study.

Researchers at Tufts University have developed a new device called ChromaSense that overcomes this limitation. Unlike older models that transmit light through a finger, ChromaSense uses a wrist-worn device to measure reflected light from skin and tissue. It first assesses the patient's skin tone and then calibrates its light levels and analytical algorithms accordingly. This skin-tone-blind approach ensures accurate readings across diverse populations. Early testing shows ChromaSense has accuracy within 1.4% to 2.9% of standard oximeters.

The innovation is not stopping at oxygen saturation. The research team is also working to integrate blood pressure detection capabilities into the ChromaSense device. Initial tests on over 2,300 adult ICU patients demonstrated up to 90% accuracy in blood pressure readings, with the goal of embedding this machine learning model into future versions of the device.