Takuo Aoyagi, a Japanese engineer whose pioneering work in the 1970s led to the modern pulse oximeter, a lifesaving device that clips on a finger and shows the level of oxygen in the blood and that has become a critical tool in the fight against the novel coronavirus, died on April 18 in Tokyo. He was 84.
His invention, which clips onto a patient’s finger, has saved millions of lives and is a vital tool in the fight against the novel coronavirus.
The pulse oximeter has become “an indispensable addition to medicine,” said V. Courtney Broaddus, a professor emeritus of medicine at the University of California, San Francisco. Historically, patients were measured by four vital signs: temperature, blood pressure, pulse and respiratory rate. “It has become the fifth vital sign,” she said of oxygen level.
