Farewell to the Inventor of the Pulse Oximeter

Takuo Aoyagi, an inventor of the pulse oximeter, an ingenious and indispensable medical device that measures oxygen in the blood and has become a staple of hospitals around the world, emerging in recent months as a key tool in the fight against the novel died on April 18. He was 84 years old.

Takuo Aoyagi’s research in the early 1970s led to the invention of the pulse oximeter, a key tool in the battle against the coronavirus. “It’s been absolutely revolutionary in terms of improving the safety of acute-care procedures as well as improving diagnostic training, because it’s such a useful sickness index,” said Lance Terada, chief of pulmonary and critical care medicine at the University of Texas Southwestern Medical Center in Dallas.

While working in the operating room or performing a pulmonary procedure, he added by phone, “you have one eye on what you’re doing and the other eye on the pulse oximeter,” a device that can be applied to the forehead or, more often, painlessly clipped to a finger or ear. “The most valuable thing about the pulse oximeter is that it’s one of very few pieces of data that we monitor in real time,”