Similar disparities have surfaced around several health devices, including Fitbits. Photographic film calibrated for white skin, for example, often created distorted images of nonwhite people until its built-in assumptions started to be acknowledged and reworked in the 1970s traces of racial biases remain in photography still today. This should give us pause, since a range of technologies based on color sensing are known to reproduce racial bias. To “see” your blood, though, the light must pass through your skin. I began to wonder exactly what this object was telling us. Our doctor said to go back to the hospital if the device’s reading dropped to 92 and stayed there, but most nights it hovered along that edge. Normal readings are in the range of 95 to 100 percent my husband could only sleep if I stayed up to make sure his readings didn’t plummet into the 70s again. When COVID-19 fevers moved through my household earlier this year, everything suddenly revolved around the number on its tiny screen, which reports oxygen saturation as a percentage. This compact medical device, costing as little as $20, clips onto a fingertip and helps gauge how much oxygen is making it to the blood. Read the medical study here and a New York Times story about the study here.ĬOVID-19 care has brought the pulse oximeter into many American homes.

Editors’ Note: On December 17, 2020, the New England Journal of Medicine published a research letter, “Racial Bias in Pulse Oximetry Measurement,” prompted by some of the issues explored in this essay.

Scientific color machine