pulseoximeter-150x150Until the coronavirus pandemic struck, few regular folks knew about pulse oximeters, much less had one on hand for urgent use. The devices, which fit over a finger, are supposed to give fast readings on the levels of oxygen in patients’ blood — a key measure of their respiratory wellness.

But the devices, whether in relatively inexpensive consumer versions or in medical-grade units used in doctor’s offices, clinics, and hospitals, are far from perfect. They suffer major inaccuracies when used by those with darker skin.

Federal regulators have known about this flaw for years. But at a time when patients, families, doctors, and hospitals relied on the devices routinely to make critical treatment decisions affecting those struggling with likely coronavirus infections, an information chasm opened. Doctors urged people to pop by drug stores and other retailers to pick up the devices, saying that they could be helpful in letting them know when their oxygen levels were dipping in concerning enough fashion that they should seek emergency treatment.