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Pulse oximeters for use at home aren’t new, but as COVID-19 continues to make health and safety a top priority, more people are looking for ways to manage their health.
Below is a comprehensive guide of all things pulse oximeters, detailing everything from what a normal read looks like, to insight into how to choose the best product for your needs.
If you’re looking for recommendations, curious how pulse oximeters even work, and who can benefit the most from using them, read on.
Pulse oximeters, which are devices used to measure heart rate and oxygen levels in the body, are usually found in a hospital or clinical setting. But at-home or consumer electronic versions are available to buy online.
What do pulse oximeters do?
Dr. Julie Chen explained, “One can use a pulse oximeter at home to measure your oxygenation, or at a clinic (or at hospitals) to monitor how much a person is oxygenating, and if blood is saturated enough with oxygen.”
How do pulse oximeters measure blood oxygen levels?
Chaim Backman, PT, EMT, said, “Pulse oximeters work by shining a light through the finger (or earlobe), and then measures the reflection of the light beam, how much light passes through, or gets reflected away from the sensor on the other side. Then, using a mathematical equation, oximeters are able to calculate how much oxygen is in the blood.”
What’s a healthy pulse oximeter measurement?
As a rule of thumb, Backman advises keeping in mind that a normal read from a pulse oximeter falls within the range of 98 to 99 percent.
Anything below 90 percent indicates something more serious and needs to be addressed urgently, Backman adds.
“Patients who have lung or heart conditions, including those with chronic obstructive pulmonary disease [COPD] and asthmatics, and those with allergies, benefit from monitoring their oxygen levels,” Hill explained.
Dr. Vicken Zeitjian, an internist, adds that COVID-19 has also increased the demand for pulse oximeters lately, as it’s a respiratory-borne illness that affects oxygenation status.
“COVID-19 is a respiratory-borne illness, and admission to the hospital is often based on oxygenation status,” Zeitjian said. “While the virus may be present with a variety of symptoms, what should prompt someone to go to the hospital is an oxygen saturation of below 90 percent.”
Chaim explains to Healthline that most at-home pulse oximeters provide accurate readings to users. But he warns that the accuracy of pulse oximetry readings can be influenced by a variety of factors.
What affects pulse oximeter readings?
For starters, nail polish color and decals can affect readings, as can acrylic or gel nails.
“Nail polish can affect pulse oximeter readings if it absorbs light at 660 nm [nanometers] or 940 nm of light,” Zeitjian explained. “This is specifically seen in black, green, and blue nail polish. Also, keep in mind that artificial acrylic nails may also affect the accuracy of pulse oximeter readings.”
Additionally, Chen suggests that the following can affect the accuracy of readings:
- low blood pressure
- skin with more pigment
- low body temperature
- intravascular dyes, which are used at a hospital for certain tests
“Dark skin and intravascular dyes in the blood cause the sensor to have difficulty in reading oxygenation, as the coloring makes it harder to read,” Chen explained.
“Low blood pressure means blood volume, and anemia means fewer blood cells, which makes the sensor have a harder time seeing the data. Similarly, low body temperature also makes blood vessels constrict, making it hard to read as well,” Chen added.
Board certified internist Jaydeep Tripathy, MBBS, MRCP, MBA-MPH, AFIH, says pulse oximeter probes or sensors can be attached to the finger, nose, ear, toes, and forehead areas.
The most accurate readings usually come from when the pulse oximeter is clamped to the finger, specifically the middle finger, as opposed to other body parts, he adds.
However, in a clinical setting, pulse oximeter probes tend to differ, according to board certified internal medicine specialist Spencer Kroll, MD, PhD, FNLA.
“Hospital-based pulse oximeters are linked to machines that measure blood pressure and temperature, and can be linked to a simultaneous measurement of a patient’s heart rhythm,” Kroll said.
“Home-based pulse oximeters only measure the pulse oxygenation and the heart rate, while hospital systems are able to provide a printout of readings. However, some pulse oximeter accessories can now be linked to smartphones, and can save data for later printout,” he added.
When shopping for at-home pulse oximeters, Zeitjian says there are many brands to choose from.
“Pulse oximeters that are labeled ‘for medical use’ and ‘FDA approved’ are what you should be looking for when purchasing,” Zeitjian advised. “These can be spotted on products found at drugstores such as CVS, Walgreens, and even Target. Most pulse oximeters also measure your heart rate, which is also a plus to many.”
Now that you know how to shop for at-home pulse oximeters, below are eight expert-approved products to keep on your radar, whether you’re using one for yourself or your loved ones.
“This pulse oximeter is FDA approved, and features great nanosensors with high-level detection,” according to Chen. “Both units from the brand [Pulse 7 Pro and Pulse 9 Pro] are also able to provide results in a short time frame, which can be useful to users on a time crunch.”
Best basic or simple pulse oximeter
“The SantaMedical Generation 2 pulse oximeter is available for a reasonable price, and has a unique auto shut-off feature after 10 seconds,” Chen explained. “This oximeter also features only one button for ease of use and requires AAA batteries to power it.”
Ear pulse sensor for tabletop oximeters
“Unlike other ear pulse oximeters, this does require a tabletop set to hook up to it, which can be useful to those who want a product with easy setup,” Chen told Healthline. “However, I generally don’t recommend ear pulse oximeters, since they are usually more expensive and less easy to use.”
Fingertip pulse oximeter
“Like a thermometer, I do recommend my patients to have a portable pulse ox handy as part of their essentials,” said board certified internist Dr. Christine Bishara. “However, patients should always consult with their doctors on their specific medical problems and use of a portable home-use pulse oximeter before purchasing.”
Innovo’s iP900AP pulse ox is available in two models, both of which made the list. The Premium shares the same features and construction for fingertip use with visual and numeric readouts on an OLED display. If you don’t need an alarm feature, the Premium iP900AP may work well for you.
Pulse oximeter for kids
“This handheld pulse oximeter can easily be put around soles or palms on children,” Chen said. “However, keep in mind that they are more expensive than oximeters that are used on the finger or toes.”
Oximeter with alarm
“This pulse oximeter has an alarm (which can be muted) and six different layout options,” Chen said. “It’s also ready to use out of the box, as it requires AAA batteries to power it.”
The main difference between the two Innovo iP900AP models is that this one, the Deluxe, has an alarm.
Forehead sensor for pulse oximeters
“Covidien has an oximeter that contains forehead pulse attachments,” said Chen. “However, oximeters like these are more expensive, and require a tabletop system in order to get a full reading.”
“Continuous monitoring should really be reserved for a hospital setting only,” Bishara explained. “This is because pulse ox readings should always correlate with clinical findings that are closely monitored in this type of setting. However, Philips Respironics offers continuous monitors for hospitals, as well as portables for patient use.”
In short, pulse oximeters are used to monitor oxygen levels in the blood. Those with underlying respiratory and heart conditions benefit most from using these devices, as well as those with COVID-19.
When using a pulse oximeter, a healthy range to look out for is between 98 and 99 percent, while anything under 90 percent requires medical attention.
When shopping for pulse oximeters, it’s wise to look for labels that guarantee safety and efficacy. Similarly, while there are many oximeters available for purchase, it’s best to stick with those that are attached to the fingertips, as they’re often the easiest to use.