Instrument manufacturer Roland has launched Zentracker, a mobile app that lets users record multitrack audio and apply sound effects. The app is now available…
Pulse oximetry uses non-invasive photon technology to measure the redness of human blood. Oxygen saturation is essential when monitoring hospitalized patients and is now being used by extreme athletes to maximize physical performance. The reactivity of oxygen drives the main energy generation system of the human body. The inventors of this technology (Masimo Corporation) recently won a landmark US $467 million dollar patent infringement lawsuit.
Mitochondria are masters of oxygen. In the presence of oxygen, they generate the adenosine triphosphate energy (ATP) that powers our muscles and vital organs. Mitochondria are the oxygen-consuming high-efficiency furnaces (inside each of your 37 trillion cells) that convert sugar and body fat into cell energy. Without oxygen, cells revert to anaerobic glycolysis for net gain of only 2 ATP per glucose molecule. With oxygen, mitochondria can produce 34 ATP per glucose…17 times more energy!
The first step in understanding how mitochondria achieve this energy advantage is to understand oxygen. A single atom of oxygen (element “O”, atomic number 8) has 8 protons and 8 electrons. Two of these electrons are unpaired, making O highly reactive because it is more stable when these electrons are shared with other atoms. An atom of O is therefore very short lived and will readily combine with other nearby atoms to create other molecules such as H2O (water), CO2 (carbon dioxide), Fe2O3 (iron oxide, rust), and even with itself to form O2 (what we commonly call oxygen). An oxygen atom basically wants to combine with everything and anything, driving many chemical reactions inside and outside the body.
It was once thought that oxygen was a prerequisite for life. However, it is now believed that life on Earth originated without oxygen. Oxygen would have been too reactive and resulted in far too simple chemicals, rather than the more complicated chemicals required for life to begin. The classic Miller-Urey experiment (first performed in 1953) demonstrated that if the gases presumed to be present in Earth’s primitive atmosphere (water, methane, hydrogen, carbon dioxide, and ammonia, but not oxygen) are exposed to electrical spark, many organic molecules are produced including: 22 amino acids (the building blocks of proteins), nucleotides (the building blocks of DNA), and sugars. Life first developed when these organic chemicals combined in shallow cesspools at the edges of the oceans, under anaerobic (zero oxygen) conditions.
Two of the greatest leaps in evolution were photosynthesis (the capture of solar energy and production of oxygen) and oxidative phosphorylation (the use of oxygen to create more energy). Without oxygen and without mitochondria, our early ancestors would literally not have had the energy to crawl out of the primordial ooze. When you exercise it is easy to take for granted the air you breathe, but inside every one of your cells, your mitochondria turn the reactivity of oxygen into athletic power.
In the hospital situation, pulse oximetry is part of the standard of care when monitoring critically ill patients and during medical/surgical procedures. More immediate than blood pressure and more telling than heart rate alone, falling oxygen content in the blood tells healthcare workers that the patient is in serious trouble. When the oxygen desaturation alarm goes off, doctors and nurses pay attention.
Oxygen is transported by the hemoglobin in your red blood cells. Each hemoglobin molecule can old four oxygen molecules. Hemoglobin is a dynamic molecule that changes shape as it binds and releases oxygen. This allows hemoglobin to bind oxygen faster in lung alveoli and release oxygen faster in capillaries. Medical students are taught the hemoglobin dissociation curve with the postage stamp analogy. The four bound molecules of oxygen are like a square of four postage stamps.
Once the first stamp detaches (two tears) it facilitates release of the other three stamps (one tear each). Likewise, when oxygen binds hemoglobin it alters its chemical configuration, turning the hemoglobin bright red. The fingertip clamp of a pulse oximeter shines and measures light to detect this redness to calculate oxygen saturation. Masimo further refined the accuracy of this non-invasive photon-based technology make it the leader in pulse oximetry and patient monitoring.
As mentioned in Chapter 10 of our book, the recent miniaturization of this technology allows oxygen measurement in athletes outside of the laboratory setting, so oxygen saturation can now be recorded when athletes train outdoors in practical situations. Masimo pulse oximetry is used by athletes such as Dotsie Bausch (2012 Olympic silver medalist in women’s team pursuit cycling) and Stig Severinsen, PhD (Guinness Book of World Records holder for longest underwater breath hold at 22 Minutes).
In the patent infringement case (which began in 2009) Masimo Corporation sued Philips Electronics North America Corporation for using its pulse oximetry technology without license or permission. Philips’ weak defense was that Masimo’s patents were void because they were “obvious” and described inadequately. In 2014 a jury decided that Philips did not prove those claims and awarded Masimo US$467-million, a figure that was upheld on appeal in 2015. This lawsuit proves the value of this ground-breaking technology. The global patient-monitoring device industry is expected to be worth US$22.2-billion by 2018. More important than these huge monetary figures, the practical use of oxygen technology has saved countless human lives.
Full disclosure: When I was writing my book with Greg LeMond, The Science of Fitness, Masimo had simultaneously developed a new portable pulse oximeter. Because our book is based on oxygen consumption by mitochondria, I contacted Masimo and each author received a gratis iSpO2 device to evaluate. No money was exchanged. We reviewed the device in our book and Masimo mentioned our book in a corporate product press release.
Featured image: Masimo’s iSpO2 portable pulse oximeter for Android smart phones. An iPhone version is also available. Photo by Masimo Corp.