#BLOOD OXYGEN METER SKIN#
#BLOOD OXYGEN METER PROFESSIONAL#

It uses a pair of LEDs вЂ“ one for IR and one for red visible light вЂ“ and a single photosensor, Figure 1. Q: So how does pulse oximetry actually work?ДЄ: The optically based SpO2 approach is elegant and simple in concept, but is fairly complicated in practice.

Reference 1 provides more historical background. Since then, improvements in LED performance (color accuracy, consistency of output, and other factors) and photodetector performance have been key parts of the success of turning the concept into a very practical and inexpensive reality. They first introduced the use of LEDs for the red and infrared light sources, resulting in continuous, real-time, noninvasive oxygen saturation readings.

Q: When did LEDs enter the story?ДЄ: In the late 1970вЂ™s, the Biox Corporation in Colorado made significant advances in pulse oximetry, using two-wavelength measurements.

#BLOOD OXYGEN METER SKIN#

There were other, more advanced attempts along the way, focused on a) developing the needed light sources at the right wavelengths and corresponding optical-electrical sensors, and b) better understanding of the relationship between light transmission at various wavelengths and SpO2 despite variations in blood flow, skin tone, blood pulsing, and many other factors. (It was later determined that oxygen insensitive-signals were not due to the green light filter but instead to infrared light.) The earlobe was used as the measurement region.ДЄ: Absolutely not. Q: WhatвЂ™s the historical background (in brief, please)?ДЄ: Between 19, Glenn Allan Millikan (an American physiologist working in Britain) used two wavelengths of light from an incandescent bulb fitted with optical filters to produce a rough but practical, all-analog, ear-based oxygen meter dubbed вЂњoximeter.вЂќ He noted that light transmitted through a red filter was sensitive to oxygen saturation while light passing through a green filter was independent of oxygen saturation. This FAQ will look at how this low-cost, fingertip-based, easy-to-use, and accurate approach to SpO2 measurement was developed, how it works, and how it is realized with modern ICs.

#BLOOD OXYGEN METER PROFESSIONAL#

It can be used in clinical settings as well as at home, and no medical or professional experience is needed. ДЇorward to the present, and you can get a small, clip-on pulse-oximetry unit for about $30-$50 which goes on the finger, and reads out the SpO2 level effortlessly in real time it is a function which is even built into some wearables. Obviously, this is invasive, time-consuming, costly, and canвЂ™t be done on a continuous basis, or even frequently. The patientвЂ™s blood would be drawn using a needle, and then the sample sent off to a lab. Just a few decades ago, determining the vital medical parameter known as blood oxygen level - formally called peripheral capillary oxygen saturation, or SpO 2 (often written out as SpO2)) - was a challenge. It is now trivial and non-invasive to measure blood-oxygen saturation SpO 2, thanks to LEDs, algorithms, and ICs for pulse oximetry - and itвЂ™s a very long way from having to draw blood and send it out for assessment.

Blood oxygen meter