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The little devices are usually attached to your finger and painlessly check your blood to see how well your lungs are working. However, the Apple Watch Series 6 integrates them directly into the smartwatch.
When doctors pointed out that people with the coronavirus often come to hospitals with abnormally low levels of oxygen, pulse oximeter sales skyrocketed, especially after a New York Times article recommended that they be used to detect a condition known as ” silent hypoxia “is called. “which can indicate a coronavirus infection.
However, questions and controversy still surround the use of pulse oximeters at home, especially when monitoring for COVID-19. It’s still not entirely clear whether pulse oximeters can help detect coronavirus infection or whether their widespread use can help contain the spread of COVID-19 altogether.
Here’s what pulse oximeters do, how they work, what the results mean, and how accurate they can be.
Pulse oximeter: vital signs at your fingertips
A pulse oximeter is a small medical device that measures your heart rate and blood oxygen saturation. It is usually attached to your finger, but it can also be attached to your ear, nose, toe, or forehead. With Apple Watches, it’s the sensor on the bottom of the watch, the part that rests on the top of your wrist that takes the measurement.
Some pulse oximeters are battery operated and provide real-time results on a small LED display on the device. Others are wired to a separate vital signs monitor that uses other sensors attached to your body to record even more accurate information about your heart rhythm, body temperature, and blood pressure.
How pulse oximeters measure heart rate and oxygen
A pulse oximeter measures your blood oxygen saturation and heart rate by shining a light through your skin and detecting both the color and movement of your blood cells. Oxygenated blood cells are bright red – oxygen depleted cells are dark red.
The pulse oximeter compares the number of light red blood cells with the dark red blood cells to calculate the percentage of oxygen saturation. For example, a value of 99% means that only 1% of the blood cells in your bloodstream are no longer oxygenated.
Every time your heart beats, your blood pushes your blood through your body in a rapid pulse (which is why “pulse” is another word for “heart rate”). A pulse oximeter uses light to detect this movement and calculate your heart rate in beats per minute (BPM), basically like every Apple Watch since the first.
What is healthy oxygen levels and a healthy heart rate?
According to the Mayo Clinic, normal pulse oximeter oxygen levels are between 95% and 100%, and less than 90% is considered dangerously low or hypoxic. Some doctors have reported COVID-19 patients hospitalized with oxygen levels of 50% or less.
A normal resting heart rate is between 60 and 100 BPM. As a rule, lower is better, as a slower heart rate is usually indicative of a strong cardiovascular system.
Can a pulse oximeter detect COVID-19?
Not exactly. Although many doctors report that patients with COVID-19 have dangerously low blood oxygen levels, COVID-19 is not the only disease that can cause such a problem. Chronic lung diseases like COPD, asthma, and other non-COVID-19 lung infections can also lead to low oxygen levels.
Low oxygen levels alone are not enough to diagnose COVID-19, but your doctor will want to know, especially if you notice levels dropping over time. If you’ve been diagnosed with COVID-19, your doctor may want you to monitor your oxygen levels to see if your condition is getting worse or better.
How Accurate Are Over-the-Counter Pulse Oximeters?
As with any electronic device, not all pulse oximeters are created equal. A 2016 study of inexpensive pulse oximeters concluded that several inexpensive consumer devices provided very inaccurate readings.
Some pulse oximeters have been approved by the FDA, which means they should meet FDA standards for accuracy. Note that there is a distinction between “FDA Approved” and “FDA Approved”, with “cleared” being the less stringent of the two. However, Class II medical devices such as pulse oximeters are typically “erased” rather than “approved”.
You can search for pulse oximeters on the FDA approved list by visiting the FDA Premarket Notification website and search for “Pulse oximeter” by doing Device name fieldwith or without manufacturer name.
How Much Should I Spend on a Standalone Pulse Oximeter?
In the 2016 study that found most inexpensive pulse oximeters to be relatively inaccurate, “inexpensive” was defined as a cost of less than $ 50. Pulse oximeters that have been approved by the FDA typically range from $ 50 to $ 60 and well into the hundreds and even thousands of dollars.
Where can I buy a pulse oximeter if I can’t get an Apple Watch 6?
Standalone. You can also check out stores like Walmart, Amazon, and eBay, as well as most brick and mortar drug stores, grocery stores, and large stores.