Smartwatches are the closest thing we have to genuine-time travelers. They’ve gone past just telling the time; they now offer a myriad of functions that transcend your expectations of what’s possible. And one of those functions is measuring blood pressure. But how does it work? This post will explore what smartwatches are and if they’re the best way to measure blood pressure.
The smartwatch is a piece of technology that looks like a small watch. It has a screen that displays information like texts, emails, phone calls, and other emergency alerts with sounds and vibrations. But they also sport fitness applications that can track your movements and even measure your heart rate. That’s right, some smartwatches offer blood pressure monitoring as one of their functions!
How do smartwatches measure blood pressure
How does it work? Wearable blood pressure monitors are not new technology by any stretch. But by including the feature in smartwatches, companies have made it cheaper and more accessible than ever before. Smartwatches use sensors to simultaneously measure both sides of the heart for an accurate blood pressure reading. This isn’t possible with manual blood pressure monitoring, the most common way of measuring blood pressure at home.
How do smartwatches measure blood pressure? Several different smartwatches can measure your blood pressure. The Omron HeartGuide is one such model. It has two inflatable arms that measure your heart’s beats as well as your pulse, sending the information to an app on your smartphone.
There’s also the Withings Blood Pressure Monitor, which connects using Bluetooth to a compatible smartphone and uses a cuff that inflates automatically with air and records your pulse and systolic/diastolic blood pressure, then sends the information to you via smartphone.
What factors affect blood pressure readings?
A study conducted by the U.S. National Library of Medicine found that people with similar average blood pressure responses experienced slightly different readings on the Omron and Withings smartwatches.
While there wasn’t enough data to determine exact causes, some of the factors contributing to this discrepancy include physical differences, like being a male or wearing tight clothing. Other factors include how fast you are moving, how stressed or anxious you are, and even how fast or far you’re running/walking.
Are smartwatches accurate for blood pressure?
Like those made by Samsung or Fitbit, smartwatches are all the rage now. They can monitor your steps, heart rate, and even blood pressure. They’re so popular that a study in 2016 found they might be as accurate as a professional blood pressure monitoring device.
This article explores the accuracy of smartwatches and what users need to know before purchasing one.
Smartwatches and blood pressure
A study published in the journal Hypertension examined the accuracy of four popular smartwatches in measuring blood pressure. The researchers recruited 22 healthy volunteers between 18 and 45 who had a normal BMI. They all had an Apple Watch Series 1, Samsung Gear Fit 2 Pro, Garmin Vivoactive 3, or Fitbit Charge 2. Both men and women were included to see if one brand was more accurate for men or women.
The volunteers visited the lab three times and participated in a 10-minute rest period at each session. The first was 30 minutes after waking up, the second was 10 minutes before going to bed, and the third was lying down in a resting position. Each of them wore their watches on their dominant wrist, taking them off for the rest of the session.
For each measurement, blood pressure was measured with an automated sphygmomanometer validated by an experienced technician. The participants laid down on a hospital-grade pneumotach with both arms at rest and then applied just enough pressure to feel slight discomfort but not enough to be painful.
A cuff was placed around the upper arm, and then the sphygmomanometer was attached. This was used to measure blood pressure through each of the measurements.
The researchers compared their results for all of their participants to those from a third-party expert who had twice measured blood pressure in each group at home. The average difference between devices (Apple Watch Series 1, Vivoactive 3, and Charge 2) and the second expert’s readings was 8 mmHg.
This is not very different from what you’d expect – your doctor may measure your blood pressure four times at home, so that’s an average of 0.8 mmHg is just 6%.
On average, the smartwatches were pretty accurate for measuring blood pressure. Comparing them to a professional medical device did show that they were slightly off but not by much. Overall, they averaged less than 10% difference from the lab-based measurements.
The researchers note that these results are in the range of those found in other studies, such as an average error of 7 mmHg for wrist-held devices. A review of 28 previous studies found similar levels of accuracy.
The study highlights some limitations, however. Only three brands were evaluated, and all of them used a specific type of cuff: automatic and oscillometric with an attached stethoscope to guide inflation.
What also affects your reading is how dehydrated you are. Your body’s ability to process blood is affected by dehydration and can contribute additional upwards pressure on your systolic blood pressure readings.
Another factor that can affect blood pressure is race or ethnicity. People of African descent are known to have slightly higher readings than people who aren’t. This is likely due to their larger heart size and earlier estimated age at birth, making them more susceptible to high blood pressure.
What are the benefits of using a smartwatch to measure blood pressure? There are several reasons why you might want to use a smartwatch as a way of measuring your blood pressure at home. The first one is price: it’s not uncommon for an Omron smartwatch to cost as little as $100, while a manual wrist cuff will set you back hundreds of dollars.
The second important point is that smartwatches are incredibly easy to use. You strap it on and let it do its thing. There’s no need to wait for your blood pressure to come down between readings or try and get the cuff over your arm… With a smartwatch, you can put it on and walk away while measuring everything for you.
Is a smartwatch the best way to measure blood pressure? Yes, but only if you’re using a high-quality one that provides accurate readings within 30 mmHg of mercury (that’s about 1-2 mmHg higher than manual cuffs).