Development of Pulse Oximetry

In 1972 the Japanese bioengineers Takuo Aoyagi and Michio Kishi, working at the company Nihon Kohden, built the first pulse oximeter, a device that estimates the oxygen saturation of arterial blood by comparing how much red and infrared light the pulsing blood absorbs. The surgeon Susumu Nakajima and colleagues tested the device on patients and published their results in 1975, and commercial versions followed soon after, with Minolta releasing the first finger worn pulse oximeter in 1977 and the American companies Biox and Nellcor introducing their own versions in 1980 and 1983. By 1987 pulse oximetry had become a standard part of monitoring patients under general anesthesia in the United States, and it subsequently spread into recovery rooms and intensive care units as a routine, continuous check on a patient's breathing.