Today, May 17, is World Hypertension Day. So, a good day to review one of the latest gadgets to measure your blood pressure, I hope. I’ve used a lot of these devices over the years, from the excellent Withings BPM Connect to the Samsung Galaxy Watch 4, and the Huawei Watch D (which has a band that inflates to measure your blood pressure on your wrist in a similar way to a standalone inflatable cuff. But the neatest and most discreet yet is the Aktiia 24/7 Blood Pressure Monitoring Bracelet.
The Aktiia bracelet is a one-function gadget. It doesn’t tell the time, or count your steps. Instead, this slim, light, demure-looking device measures your blood pressure, something the Apple Watch does not manage.
The Aktiia does its readings optically, as does the Samsung Galaxy Watch 4, for instance. There’s no inflatable cuff to strap around your upper arm: the bracelet does the measurements from your wrist alone.
This means that you need to calibrate the Aktiia once a month, and an inflatable blood pressure cuff that connects wirelessly to the bracelet is helpfully supplied for this purpose. That’s something Samsung doesn’t provide, by the way.
The bracelet design couldn’t be simpler: a slim silicone strap fastens on your wrist—a little above the wrist bone is recommended for most accurate readings—and under the strap, pressed against the flat part of the top of your wrist, is the lozenge of tech that does the readings.
It’s a shiny black rectangle, not that you really see it very often as it’s under the matte-black silicone strap, with an optical sensor that is pressed against the skin. A green light shines on the skin when it’s taking readings.
If the design sounds understated, perhaps it’s because this is a gadget that goes about its work quietly in the background. There’s no screen and you never need to look at it except when you fasten and unfasten it. It can remain hidden under your sleeve.
It takes a dozen or more readings a day and, when you open the Aktiia smartphone app, the data is uploaded to your phone.
When you go to the doctor and have your blood pressure taken, it can often be high. The apprehension at seeing the result, the tension caused by being in a doctor’s surgery and so on contribute to unnaturally high results. This is sometimes called the white coat effect.
So, the Aktiia is designed to overcome these stresses and give you accurate readings by measuring in the background. You don’t know it’s happening unless you happen to glance at your wrist at the exact moment it’s doing it and you spot the green light. This is one of the gadget’s great advantages, though it also relates to its one flaw: you can’t cause the Aktiia to take a reading on-demand.
Sure, I understand that the whole point of it is you don’t know when it’s taking a reading, and just knowing that can be enough to cause some people’s blood pressure to rise. Even so, I’d like to have it as an option. The manufacturer tells me that it’s assessing the feasibility of this while saying, and I agree, that passive readings have the most benefit.
You need to be sitting quietly for a period to time for the reading to complete. I’m told that doing something sedentary such as watching TV for several minutes can be enough to trigger the bracelet into taking a reading but, even so, there are often times of the day for me when the app has not taken successful measurements.
You don’t know this until you check out the smartphone app. My typical day means that, apparently, I’m not sitting still enough long enough between lunchtime and early evening for any successful readings to take place, so there’s a big gap in my day’s results. Overnight readings are consistently achieved, so my blood pressure when I’m sleeping is covered.
The app is clear and helpful, with colored markings indicating whether your systolic and diastolic readings are optimal or not. Note that you need an active internet connection to use the app at all, which can be frustrating if you’re out of wifi range, for instance, and want to check earlier data. Surely the app doesn’t need that connection to show you what’s already in the app?
Each day shows the percentage of readings that have been “in range” and it becomes mildly addictive to check out your readings and compare today to yesterday, for instance. Helpfully, the app can show you charts for what is optimal and what’s not, with figures both for the FDA and EU—these agree on what is optimal and what is extremely unsafe, but in between are slightly different.
It’s worth noting that the Aktiia Bracelet is not water-resistant—it points this out in the instruction manual, but I almost missed it. So, you need to take it off when showering, swimming, bathing and so on.
In the app, today’s page will say, “Today, April 27” or whatever, whereas previous days just have the date. It would be more helpful, I’d say, if each day said the day of the week as well, so I didn’t have to think twice to remember what I was doing that day.
I can’t definitively tell you how accurate the Aktiia Bracelet is, though it seems to come up with results very close to a regular blood pressure cuff when measured side-by-side. And Aktiia says it meets the ISO81060-2 standard required for home blood pressure cuffs.
But I can tell you that the data it’s provided me with has been fascinating, and I’ve been glad to know that it’s easy to share it if I need to. I enjoy having an extra source of data, and how its results correlate to how I’m feeling. Having a bracelet that regularly measures blood pressure while I’m sleeping is particularly useful.
The Aktiia 24/7 Blood Pressure Monitoring Bracelet is on sale from aktiia.com in Germany, Austria, Italy and France, where it costs 209.99€, though is currently reduced to 189.99€. In Switzerland the price is 239.99CHF, currently down to 219.99CHF. And in the U.K. and Ireland, it’s £199.99, though currently on offer at £179.99. The reduced price, for World Hypertension Day, runs until Thursday, May 19, 2022.