Early in the COVID-19 pandemic, research from the University of Michigan uncovered inaccuracy in readings based on race when using pulse oximeters, finger-tip devices used to determine how much oxygen is present in the blood in patients in respiratory failure. This work was followed by other studies from around the world finding the same inaccuracy in many different critically ill patients, and that it seems to have led to failure to provide timely treatment in Black COVID-19 patients.