What is pulse oximetry and how does it work?

Pulse oximetry is a noninvasive method that enables rapid measurement of the oxygen saturation of hemoglobin in arterial blood.1 It can rapidly detect changes in oxygen saturation, thus providing an early warning of dangerous hypoxemia.23

How it works: A pulse oximeter (like the Nonin GO2) shines light at two wavelengths—red and infrared—through a part of the body that is relatively translucent and has good arterial pulsed blood flow (e.g., finger, toe, earlobe). The ratio of red to infrared light that passes through the measurement site and is received by the oximeter’s detector depends on the percentage of oxygenated versus deoxygenated hemoglobin through which the light passes.2 The percentage of oxygen saturation thus calculated is referred to as the percent SpO2.3

An SpOof greater than 95% is generally considered to be normal.

An SpO2 of 92% or less (at sea level) suggests hypoxemia

By using a finger pulse oximeter you get an accurate, almost instant indication for whether you can continue on with your activity or if you need to take a break or consider contacting your physician. It gives you or your loved one the confidence to continue the life you want to lead with objective and highly accurate information, that way you don’t have to rely solely on subjective symptoms to determine blood oxygen levels.

Building up strength is important – and that requires activity. A personal finger pulse oximeter was designed so that individuals can monitor their pulse rate and oxygen saturation rate wherever they go. It is ideally suited to help individuals manage their own chronic respiratory disease or that of their loved one.

Chronic Obstructive Pulmonary Disease, commonly known as COPD, is the most common lung disease marked with difficulty breathing, chronic bronchitis and emphysema being the two main components. Nonin Medical is the inventor of the world’s first fingertip and wireless pulse oximeter called the GO2™. Nonin has done extensive research with patients and their caregivers and understands the desire to continue to live a normal and full life with a diagnosis of COPD.

To learn more about Staying active with COPD, view a video excerpt from Lifetime TV’s The Balancing Act, Maintaining An Active Lifestyle and Ensure The Most Accurate Oximeter.

1. Neuman MR. 1987. Pulse oximetry: physical principles, technical realization and present limitations. Adv Exp Med Biol 220:135-44.
2. National Health Service (UK) Center for Evidence-based Purchasing. 2009. Project initiation document: Pulse oximeters.
3. Holmes S, and SJ Peffers. 2009. PCRS-UK Opinion Sheet No. 28: Pulse Oximetry in Primary Care. www.pcrs-uk.org