- Works with armband-like precision
- Automatic measurements
- Discreet design
- Simple to use app
- Good autonomy
- Measures blood pressure and resting heart rate only
- Few in terms of insights (this will change with future updates)
We are getting closer to the day when wrist-based blood pressure monitoring will be a normal thing. That could happen later this year, more likely in mid to late 2022 and beyond.
One of the first real entrants in this market is the Swiss startup Aktiia. The company has just started to market its optical wrist blood pressure monitor (BMP) in the UK (seen on aktiia.com). From the beginning of May, the availability will be extended to Germany, Austria, France and Switzerland. This will be followed by the United States in the near future once FDA approval is obtained.
Many adults are affected by hypertension, but up to one in three may not know they have it. They feel strange pinching or headaches, but simply explain it by the fact that they feel a little uneasy. And that’s the paradox and why high blood pressure is sometimes called the silent killer. You don’t know you have a problem until it’s too late.
Home BPMs can be very useful. Taking regular measurements is especially important as you get older – the effects of an unhealthy lifestyle tend to compound over time.
Whether smart or traditional, BPMs usually come in one of two forms: those for the upper arm and those for the wrist. Almost all use some type of inflatable cuff technology.
We’ve yet to see a major brand offer a wearable wristband that uses optical sensors to measure blood pressure with armband-like accuracy. There is a lot of unrest in this area, however.
Samsung may be taking the lead with its Galaxy series. However, these measurements are no match for the accuracy of an armband. Fitbit has also just announced a study to find out if its Sense smartwatch can take such readings.
Part of the problem is that the arteries in the wrist are narrower and shallower under the skin than those in the forearm. This makes taking blood pressure from this location more difficult.
There is, of course, the Omron HeartGuide. But it’s a watch-sized sphygmanometer, so it doesn’t use optical sensors. It’s basically a miniature armband built into a smartwatch. Omron filed over 80 patents to create the thing a few years ago.
Which leaves us with the traditional BPMs. They work well, but many of us don’t use them regularly.
The Aktiia bracelet promises something never seen before. Automatic, clinically validated daytime and nighttime blood pressure measurements taken at the wrist with optical sensors. No buttons to press, nothing to do but wear it.
Does it work as advertised? I have been living with the Aktiia bracelet for almost a month. Read on to find out what I did with it. My interview with Aktiia CEO Micheal Kisch is also worth reading.
- discreet design
- no display, the application displays data
- uses an optical heart rate sensor and proprietary algorithms
- 9 day battery life
In the box, the Aktiia system comes with the measurement bracelet, a traditional blood pressure cuff, charging cables and a small charging stand. There is also a small instruction booklet if you want to read it. I usually dive straight in without spending a lot of time on the literature. Fortunately, the information in the smartphone app was enough to guide me through setup and use.
What surprised me a bit, however, was that there was a traditional Aktiia-branded armband in the box. You will find during the initial setup that you need to calibrate the device before first use and then once a month. Not a big deal, but something to be aware of.
The bracelet itself is very discreet. It consists of a metal central unit attached to a Velcro strip. The strap passes through two rings on the main unit and is held in place via a traditional watch buckle. Once lit, there is no risk of it falling.
It’s a one-size-fits-all deal. But the strap is adjustable so it can fit a variety of wrist sizes, from 14cm to 21cm. It is the same with the initialization armband. Aktiia says that the armband can accommodate arms with a circumference between 22 and 42 cm. That’s most people.
What I really liked was the small form factor of the Aktiia bracelet. The thing does not replace a traditional activity band. It only captures blood pressure readings and resting heart rate. So if you have a fitness tracker and a smartwatch that you use daily, Aktiia’s minimalist design allows you to wear it on the other wrist. Some might even confuse it with jewelry.
under the hood
As for the underlying technology, the Aktiia system uses common optical heart rate sensors and proprietary algorithms to measure an individual’s blood pressure at the wrist. The system works by analyzing the changing diameter of the arteries with each heartbeat. Monitoring is done automatically at regular intervals, so users can see how their blood pressure changes at different times of the day and night.
The laptop has a 9-day battery life so it doesn’t need to be charged often. Just wear it like you would any fitness tracker and go about your day.
However, you must take it off when taking a bath or bathing. This is because the wristband is only splash resistant. Keeping it for swimming would be a bit useless, anyway. Aktiia takes measurements only during periods of rest. It will take readings when you are lying in bed and possibly at times when you have been sitting for a while.
After about a week, I found myself taking it off when I walked to the door. I did this knowing that I wouldn’t really run out of data. Capturing blood pressure while walking or exercising is unnecessary, even with a traditional measuring cuff.
For this purpose, the Aktiia wristband has an accelerometer inside. But it’s not for counting your steps or calories burned. This is to know if you are still. By measuring movement, the wristband can assess when accurate measurements can be taken.
- readings are captured automatically
- works while you are at rest
- requires calibration once a month
Before first use, you will need to calibrate the bracelet with a traditional blood pressure cuff. As mentioned, this is included in the box.
Calibration is done via the Aktiia smartphone app. This will guide you through a brief setup procedure. You will also be guided on the correct way to wear the bracelet. The instructions say the band should be snug but not too tight. They suggest leaving enough room for a pencil to slip between the strap and your wrist.
I followed the instructions to the letter. In the end, I found that it’s actually better to keep the strap snug as it picks up readings more frequently. So if the device fails to record measurements often enough, try tightening the band. Ensuring, of course, that there is always a comfortable fit.
The app will also help you calibrate the device. With both the Aktiia bracelet and the traditional armband, you will need to capture readings from both at the same time while in a comfortable seated position. Two individual readings will be taken one after the other to ensure accuracy.
The process can be a bit finicky and requires a bit of trial and error. It took me about 5 minutes to do the calibration the first time. For some reason the band worked much better from my right wrist than my left wrist. To make sure everything was fine, I did a few more calibrations. On subsequent trials it was much easier and worked perfectly.
Aktiia says the bracelet should be recalibrated at least once a month. Rather usefully, the application indicates the date when you must perform the next calibration.
If initialization is not completed within the required time, accuracy cannot be guaranteed. This is the reason why the company displays a disclaimer on the box. Data may not be accurate if initialization is not performed in a timely manner.
After setup and calibration, you’re good to go. The small form factor of the Aktiia bracelet coupled with the fact that it is very light means that you will quickly forget you are wearing it. In that sense, I think it really helps that the laptop doesn’t have a screen. Just be sure to charge the bracelet every week or so.
- readings can only be seen in the app
- daily, weekly, monthly trends
- PDF summary report
The results can be viewed in the accompanying smartphone app. This lets you see individual readings, averages, and share a summary report with others.
As with all such devices, a synchronization is carried out via a Bluetooth connection. It usually takes less than a minute.
The app itself is a fairly straightforward affair. There are three tabs at the bottom. The House The tab is where your blood pressure readings are. Next to it is the Devices tab where you can see the battery level of the wristband and armband. The last tab displays your Profile and settings.
Readings can be viewed and plotted on a daily, weekly and monthly basis. I estimate that on average the bracelet would take 9-10 measurements per day.
Most importantly, these readings meet the ISO81060-2 standard for accuracy. Therefore, the wearable has CE marking as a class IIa medical device (for users in the age group 21-65, excluding contraindications due to certain health conditions). Much research has gone into creating the Aktiia system. This includes 5 clinical trials and 1 million measurements to date. You can read more about accuracy at this link.
I sometimes take blood pressure readings in the morning with a traditional blood pressure cuff. Systolic and diastolic values would typically be around 8-10 points above the Aktiia readings. Which is logical. Aktiia measurements are taken while you sleep or at rest. I take measurements with a traditional cuff while seated during the day.
The app also collects averages. For me, the readings didn’t change much from day to day. But they would increase or decrease by a few points. It would depend on my activity the day before.
For example, if I was doing a particularly stressful exercise, my readings would increase slightly overnight. Also the week after a plane ride – the readings steadily dropped each day as I recovered from the trip.
But you can see the potential. The fact that Aktiia works automatically 24/7 means you can experience how changes in exercise, diet, and sleep affect your cardiovascular health. The app will plot the measurements so you or your doctor can spot the patterns.
What I would have liked to see was a bit more analysis. In addition to the daily, weekly and monthly averages, it ends with the averages for the week compared to the weekend.
But it’s on the company’s to-do list. According to the CEO of Aktiia, future software updates will bring information such as day/night analysis, the possibility to “label” the data so that the user and his doctor better understand the specific impact of the diet, exercise, medications and stress on their cardiovascular system. Targeted health and heart health tips based on each user’s unique blood pressure pattern.
Reports are another useful part of the system. You can generate a summary document for a defined period of time. This can then be viewed on your phone, downloaded as a PDF, or sent to your healthcare provider.
Here is an example of a summary report. Click on the image below to enlarge it.
The Aktiia bracelet is not intended to replace a fitness bracelet or a smartwatch. It uses optical sensors to track blood pressure at the wrist, as well as resting heart rate. Nothing else. But it does it with clinical-grade precision, automatically, multiple times throughout the day and night. For the moment, it is the only product of this type.
The bracelet’s small form factor means you can put it on and forget it. Don’t forget to recharge it every week or so. And do the calibration with a traditional cuff once a month.
Overall, I found the Aktiia bracelet to work very well. In a 24 hour period, it would capture approximately 10 readings. It’s all charted for you in the simple-to-use app, and you can generate a report to share with your doctor. The readings were where I expected. What adds confidence is the clinical validation and the fact that the wearable has CE mark clearance for accuracy.
The system is ideal for someone who wants to monitor their cardiovascular health more closely. It may also be helpful for those who are at risk or have already been diagnosed with high blood pressure. The wearable is a great tool to help you make lifestyle changes that benefit your cardiovascular health.
The Aktiia bracelet can be bought by those living in the UK. Other countries will follow soon. You can add your email to the waiting list on the website to be notified when Aktiia is available in your country.
The wristband costs £129.99 with an ongoing £6.99 monthly subscription to access the Aktiia 24/7 monitoring service. The £199.99 annual plan includes the cost of the monthly subscription.
We are a review site that receives a small commission from the sale of certain items, but the price is the same for you. Purchasing items by clicking on links in this item allows us to operate this website. We are independently owned and all opinions expressed here are our own. See our Affiliate Disclosure page for more details.