Pulse Oximetry and the Legacy of Dr. Takuo Aoyagi

Pulse Oximeters

Adapted from Special Feature on Pulse Oximeters: The invention that changed the paradigm of patient safety around the world. (LiSA (1340-8836) vol28 No3 Page237-308, 2021.03 (in Japanese)

Disclaimer: The information provided is for safety-related educational purposes only, and does not constitute medical or legal advice. Individual or group responses are only commentary, provided for purposes of education or discussion, and are neither statements of advice nor the opinions of APSF. It is not the intention of APSF to provide specific medical or legal advice or to endorse any specific views or recommendations in response to the inquiries posted. In no event shall APSF be responsible or liable, directly or indirectly, for any damage or loss caused or alleged to be caused by or in connection with the reliance on any such information.

Pulse Oximeters: The Invention that Changed the Paradigm of Patient Safety Around the World
by Katsuyuki Miyasaka, M.D., Ph.D.

Dr. Takuo Aoyagi

Dr. Takuo Aoyagi

I feel greatly honored to have been asked by the editorial board to organize a special memorial issue on Dr. Takuo Aoyagi. I would like to thank the editorial board for their wise decision to take this timely opportunity to tell the world about the great contribution Dr. Aoyagi made to humanity. Many contributors are from countries other than Japan, all of whom showed great interest in this project. They kindly agreed to search their files and memories from 40 years ago and send their memorial contributions on a tight schedule so that we would have time to translate their articles into Japanese. Drs. David J. Steward, Jeffrey Cooper and others sent their manuscripts in record time, some as short as six days and I am very grateful for the great interest shown by all.

As you read through this collection of articles, many of you will find new information and developments previously unknown to the public. I hope that this memorial will give all of us the opportunity to reconfirm what we know of the great legacy left to us by the late Dr. Aoyagi… [Continue]


Anesthesia Patient Safety Foundation (APSF)The Anesthesia Patient Safety Foundation (APSF): A 35 Year Commitment to Patient Safety
by Steven Greenberg, MD, FCCP, FCCM
In the 1970’s and 1980’s, anesthesia adverse events had reached a tipping point. It was approximated that anesthesia related mortality prior to 1985 was 1:10,000 healthy patients. A highly publicized… [Continue]

Mainstream CO2 sensor cap-ONE (TG-980P)Pulse Oximetry and Innovation – Ability to Translate Invention to Innovation
by Hirokazu Ogino
On June 20, 2015, I witnessed a historical moment in the ballroom of the Waldorf Astoria hotel in New York. Dr. Takuo Aoyagi, who invented pulse oximetry, was being awarded a Medal for… [Continue]

Lifebox Pulse OximetryPulse Oximetry: The Heart of Lifebox’s Work – Honoring Dr. Takuo Aoyagi
by Kitty Jenkin; Alex Hannenberg, MD; Atul Gawande, MD, MPH
Dr. Takuo Aoyagi’s invention of the pulse oximeter has saved the lives of millions of people across the globe. After the sadness of his death this year, Lifebox, a non-profit founded… [Continue]

OXIMET Met 1471 Pulse OximeterThe Development of Pulse Oximeters in Japan: Good Competitors, Nihon Kohden and Minolta Camera
by Ikuto Yoshiya; Akio Yamanishi
The pulse oximeter is currently one of the most indispensable devices in the medical world, like the electrocardiogram or the sphygmomanometer. Even in early spring, 2021, as SARS-CoV-2 is still… [Continue]

The Ratio of Ratios and the Nobel Prize
by Kirk Shelley MD, PhD
I was truly heartbroken to hear of Dr. Aoyagi’s passing. His remarkable genius created the device I have spent most of my life devoted to studying. He was a warm and gentle man who was profoundly humble… [Continue]

Nellcor Pulse Oximeter Prototype as delivered to us in 1982.<br /> Note the absence of the "N-100" designation, this was added at a later date as N-100A. The first commercial model was called N-100B.Nellcor: Continuous Perioperative Oximetry Comes to North America
by David J Steward MB BS, FRCPC
Instruments intended to non-invasively measure the oxygen saturation of arterial blood were introduced as early as 1942. Very rarely their potential value as a monitor in anesthetized patients was evaluated, as for example… [Continue]

N-100 Pulse OximeterAoyagi’s Legacy in the US: What Influenced Its Acceptance?
by Jeffrey B. Cooper, Ph.D.
While Takuo Aoyagi’s name was not widely known in the US, his invention of a practical way to monitor oxygen saturation has had a huge impact on healthcare, on anesthesiology in particular… [Continue]

Adoption of Pulse Oximetry into the JSA Anesthesia Safety Guidelines – The Brilliance of Aoyagi’s Intellectual Legacy – Talk of Nobel Prize
by Shosuke Takahashi, MD

Different Roles of Japanese and US Industry in the Clinical Introduction of Pulse Oximeters: Long Way from Development to Commercialization
by Hironami Kubota

Using a Fundamental Approach to Improve the Accuracy of Pulse Oximetry – The Research to which Dr. Aoyagi Devoted His Life
by Kazumasa Ito

Pulse Oximeter: Dissemination in Neonates and Its History
by Hiroshi Nishida, MD, PhD

How Pulse Oximetry Influenced Medicine and How Its Evolution Will Influence Medicine
by Joe Kiani, BSEE, MSEE

The Role Played by an Import Company in Introducing Pulse Oximetry to Japan: Me, My Company and Pulse Oximeters
by Yasuhiko Sata

Commemoration of Dr. Takuo Aoyagi’s Impact: A Tree that was Heard to Fall
by Robert J. Kopotic, MSN, RRT, PhDh