|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)
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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 Innovations in Healthcare Technology, the first for a Japanese, by the Institute of Electrical and Electronics Engineers (IEEE), the world’s largest association for electrical and electronic engineers, the founders of which included greats like Thomas Alva Edison. Even though he was 79 years old at that time, Dr. Aoyagi walked resolutely on to the stage in a tuxedo, gave an acceptance speech which, even if not fluent, was clear and powerful, and received a great ovation 1. This was a moment of recognition of the great invention by Dr. Aoyagi and of the contribution of Japan to medical safety worldwide. (Figure 1)
Nihon Kohden Corporation also takes great pride in the invention of pulse oximetry by Dr. Aoyagi, although it has since become a story of success and failure. Innovation is said to represent invention translated into implementation. Our company successfully invented pulse oximetry but has fallen behind other companies in its implementation.
Looking back into history, pulse oximetry may have been invented a bit too early, like many other inventions. In 1974 2, when Dr. Aoyagi invented the principles of pulse oximetry, semiconductor devices, such as light-emitting diodes (LEDs), had not yet become well established, and small probes suitable for clinical use could not be developed. (Figure 2) Therefore, it took nearly another 10 years before LED-mounted small probes were introduced. Also, the market for continuous monitoring of blood oxygen saturation was still not recognized. A change occurred in the first half of the 1980s, when intraoperative medical accidents became an issue in the United States. Nellcor, Inc., which was founded by Dr. New, caught the wave of technological innovation and market changes at this time, and paved the way for the implementation of continuous oxygen saturation monitoring. In the 1990s, Masimo Corporation, founded by Kiani, distinguished itself by creating the current market for pulse oximeters.
Why did Nihon Kohden Corporation fail to seize the market opportunity even though it invented the principles of pulse oximetry? A look into this problem revealed the deep gap between invention and implementation. What is required to overcome this gap is an ability different from inventive ability alone3; that is, the ability to disseminate innovative technology to the market, in other words, marketing capability. Regarding the contribution of these companies to the development of pulse oximeters, Dr. Aoyagi stated the following, in his contribution in 1990 4: “Nellcor, Inc. (snip) widely advertised the clinical importance of pulse oximeters.”
Using this past failure as a lesson, Nihon Kohden has since attempted to disseminate new inventions derived from pulse oximeters worldwide. Estimated continuous cardiac output (esCCO), first invented by Dr. Yoshihiro Sugo of our company, is a non-invasive measure of the pulse wave transit time from the electrocardiographic waveform and the pulse wave from a fingertip pulse oximeter, and provides a continuous estimate of the cardiac output 5,6,7. Considering that Dr. Aoyagi conceived of the principles of pulse oximetry during the study of cardiac output measurement using the dye-dilution method, I am deeply moved by the fact that the cardiac output can also be estimated by a different method using pulse oximetry.
Similarly, “cap-ONE,” which is the world’s smallest and lightest mainstream CO2 sensor developed by Dr. Shinji Yamamori of our company, is more like a breakthrough toward implementation than invention. The achievement of microminiaturization (approximately 4 g, one-fifth compared with the previous model) using an original technology enabled its application into various clinical settings. (Figure 3) Recently, our company successfully implemented magnetic resonance imaging (MRI)-compatible mainstream CO2 monitoring for the first time in the world 8,9,10. (Figure 4)
Representative Director, President and Chief Executive Officer of Nihon Kohden Corporation
- 2015 IEEE Honors Ceremony; 2015 June. [cited 2020 Nov. 9] Available from: https://ethw.org/2015_IEEE_Honors_Ceremony
- Aoyagi T, Kishi M, Yamaguchi K, Watanabe S. Improvement of an earpiece oximeter. Japanese Journal of Medical Electronics and Biomedical Engineering. In: Abstracts of the 13th annual meeting of the Japanese Society of Medical Electronics and Biological Engineering. 1974; Oosaka. vol 12 suppl: 90-1.
- Geoffrey A. Moore. Crossing the Chasm ver.2. 2014; Tokyo, SHOEISHA.
- Aoyagi T, The birth and theory behind pulse oximeters. The Journal of Japan Society for Clinical Anesthesia. 1990; 10: 1-11. (In Japanese)
- Sugo Y, Ukawa T, Takeda S, et al. A Novel Continuous Cardiac Output Monitor Based on Pulse Wave Transit Time. Annu Int Conf IEEE Eng Med Biol Soc 2010; 2010: 2853-6.
- Yamada T, Tsutsui M, Sugo Y, Sato T, et al. Multicenter study verifying a method of noninvasive continuous cardiac output measurement using pulse wave transit time: a comparison with intermittent bolus thermodilution cardiac output. Anesth Analg 2012; 115: 82-7.
- Maglioccav A, Rezoagli E, Anderson TA, et al. Cardiac Output Measurements Based on the Pulse Wave Transit Time and Thoracic Impedance Exhibit Limited Agreement With Thermodilution Method During Orthotopic Liver Transplantation. Anesth Analg 2018; 126: 85-92.
- Takatori F, Yamamori S, Inoue M, et al. A novel mainstream capnometer system for non-intubated pediatric patients requiring oxygen administration. Conf Proc IEEE Eng Med Biol Soc. 2011; 2011: 1189-92.
- Takahashi D, Hiroma T, Nakamura T. PETCO2 measured by a new lightweight mainstream capnometer with very low dead space volume offers accurate and reliable noninvasive estimation of PaCO2. Research and Reports in Neonatology. 2011; 1: 61-66.
- Napolitano N, Nishisaki A, Buffman HS, et al. Redesign of an Open-System Oxygen Face Mask With Mainstream Capnometer for Children. Respir Care. 2017; 62(1):70-77.
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