What Is Pulse Oximetry


Pulse oximetry is a noninvasive method for measuring a patient’s oxygen level (SpO2) and heart rate. In short, it’s a simple, painless way to determine how effectively oxygen is being transferred to different parts of the body and how often the heart is beating. There are many types of pulse oximetry devices—commonly referred to as pulse oximeters—and all of them use wavelengths of light to measure the amount of oxygen in the blood. Pulse oximeters are used to assess whether patients are receiving enough oxygen during strenuous activities, while taking certain medications or undergoing surgeries requiring sedation.

Today’s clinicians use pulse oximetry measurements to address emerging medical issues and drive favorable treatment outcomes. Pulse oximetry is most commonly achieved using a finger pulse oximeter—a simple, lightweight device that attaches painlessly to the index finger. And with the advent of personal finger pulse oximeters, people with COPD, asthma, congestive heart failure (CHF) and other afflictions can quickly detect changes in pulse or oxygen levels during travel or at home—empowering them with the knowledge to control their condition.

How Does a Pulse Oximeter Work?

To understand how a pulse oximeter works, you have to know how hemoglobin interacts with different wavelengths of light. Hemoglobin is the oxygen-carrying protein in your red blood cells. Deoxygenated hemoglobin bears a purple-blue color, but when this protein is full of oxygen it becomes bright red. When exposed to different wavelengths of light, oxygenated hemoglobin will absorb more infrared light and deoxygenated hemoglobin will absorb more red light.

A finger pulse oximeter functions by shining red and infrared light through your finger. As these beams pass through your digit, the oximeter’s photodetector measures how much red and infrared light is transmitted through it. This process allows the device to assess how heavily saturated your blood is with oxygen, as well as your current pulse rate. Within a few seconds of measurement, these readings are displayed on the oximeter’s screen as a SpO2 percentage and bpm (beats per minute) number.

Using a Finger Pulse Oximeter

Finger pulse oximeters are built with speed and convenience in mind. All you have to do is slide your index finger into the device’s opening until it touches the built-in stop guide. Your oximeter will automatically turn on, complete a brief self-test and begin to measure your oxygen level and pulse rate. Soon after, the oximeter will display your current SpO2 percentage and pulse rate on its screen. Once you’ve finished measuring, you can simply remove your finger and put your oximeter away; the device will automatically shut off within a few seconds.

Nonin Pulse Oximeters

Nonin Medical leads the way in pulse oximetry. We invented the very first finger pulse oximeter in 1995, and have spent the past 20+ years optimizing this technology to offer the best possible results for our customers. Our mission is to empower you with the critical measurements you need to better understand and manage your health needs. Whether you intend to use pulse oximetry for in a professional setting, for self-monitoring or as a caregiver, it’s critical to invest in a high-quality device that can deliver reliable results during repeated daily use. That’s why medical professionals and patients globally count on Nonin pulse oximeters.

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PureSAT® Technology

Only Nonin pulse oximeters have PureSAT® pulse oximetry technology, which uses intelligent pulse-by-pulse filtering to provide precise oximetry measurements—even in the presence of motion, low perfusion or other challenging conditions. PureSAT automatically adjusts to each patient’s condition to provide fast and reliable readings you can act on. Nonin pulse oximeters provide peace of mind that your monitoring results are accurate—and allow you to respond more quickly and confidently when your oxygen levels become unstable.

Count on Nonin for Dependable Oximetry Solutions

Contact Nonin to learn more about our powerful pulse oximetry devices for personal use. Our team can help you find the perfect self-monitoring solution for your unique healthcare needs and goals. You can also connect with us for more insights into pulse oximetry technology and how you can use these tools to manage asthma, COPD and other challenging conditions. We’re here for anything you need.