How is your blood pressure? The wearable device market may be dominated by smartwatches and fitness trackers that perform algorithm-based estimations of everything from heart rate to oxygen levels, but now we’re seeing the emergence of devices dedicated doctors able to monitor specific medical conditions.
The Aktiia G1 isn’t the first blood pressure monitor we’ve seen, but it’s certainly a much sleeker device than the smartwatch-like BP Doctor Pro. While this device features a miniature pump and inflating air valve to monitor your blood pressure in a chunky all-in-one wristband, the Aktiia consists of two parts: a wristband and a cuff.
Why does someone need to measure their blood pressure constantly? Over a billion people suffer from high blood pressure, including 116 million in the US and 30 million in the UK. This ‘silent killer’ is hard to spot, but strains the blood vessels, heart, brain, kidneys and eyes, increasing the risk of heart attacks and strokes.
It’s really easy to use. The wristband – the 24/7 wearable – weighs just 22g and takes readings when you’re at rest. Once a month, you should calibrate it using the cuff while sitting.
The technology itself is a combination of old and new. The armband, which attaches to a smartphone via Bluetooth, is the traditional upper arm oscillometric device that can be purchased for use at home. But while home oscillometric devices are a pain and need to be used frequently, Aktiia’s armband only needs to be used once a month to calibrate the wristband, which uses the same PPG (photoplethysmography) optical sensor as smartwatches. and fitness bands.
It is medically certified and scientifically proven to be accurate within a range, but we realize that most readings are not taken when the user is in a seated position – as is the case during calibration – and the blood pressure can vary throughout the day. The results will therefore surely be affected by the time of day at which you calibrated the bracelet.
Either way, we found setup and calibration to be straightforward. Although the cuff is unpleasant in that it compresses your radial artery – as with any oscillometric device – it works well and the whole process is done step by step via the Aktiia app. During our testing period, we found the band to be unobtrusive, with battery life lasting around 10 days and recharging quickly.
His blood pressure readings were also consistent. In fact, our only complaints are that the Aktiia should be waterproof – something promised for its second iteration later this year – and that there might be a bit more information on a few other activities associated with the fight against the virus. hypertension, like a basic activity monitor. However, as a single-tower laptop designed to do one thing, the Aktiia is impressive.
Price and release date
- Out now in Europe, soon in the US
- Costs $268 / £199.99 / AU$366
Launched in 2021, Aktiia is currently sold in the UK, Ireland, France, Switzerland, Germany, Austria and Italy, having received CE marking as a Class IIa medical device in Europe. It should be available in the United States by the end of 2022 once it has been approved by the FDA, as well as in Canada.
- Bracelet and cuff design
- The bracelet weighs 22g
- Not waterproof
The Aktiia comes in two parts: a small, discreet bracelet and a larger armband to be used once a month to calibrate it. The strap weighs only 22g and comes with a 14mm wide wrist strap. On the skin side, it sports a flashing green optical PPG (photoplethysmography) sensor.
During our two-week test period, we barely noticed it, even while sleeping, with one exception. Unfortunately, it’s not waterproof, so you have to take it off every time you shower or swim. Aktiia tells us that this weakness will be fixed in the next version.
What makes the Aktiia really different from smartwatches is its armband. It’s nearly identical to upper arm oscillometric devices that can be purchased for use at home, although this one has a smaller design and uses Bluetooth to talk to the Aktiia app during a once-a-week calibration. month. It weighs 264g and measures 130 x 75 x 20mm.
- Connects via Bluetooth 4.2
- Messages and notifications from a smartphone
The Aktiia is fairly easy to install, although it takes a few minutes. You will need the Aktiia app, an account (it asks for your name, date of birth, gender, weight and height) and a code from your purchase that links your account to the cloud. You then need to pair your phone via Bluetooth to the bracelet and the armband, taking turns, then put the bracelet on your wrist and the armband on your arm.
Now it’s time to do the calibration, which is to check that the armband and bracelet are connected to your phone. It then takes two cuff readings to calibrate the system. It took two attempts to successfully pair the devices in our tests. The cuff then took a reading and told us to come back later.
Although a bit boring, medically speaking, this approach is perfect. After all, people with high blood pressure don’t have to be stressed to install a gadget. A few hours later, we successfully repeated the process and were notified by the app that another calibration with the cuff would be required in a month.
Overall we found the setup to be surprisingly smooth, although we do question the overall accuracy of the calibration given that blood pressure varies over a 24-hour period; shouldn’t it be calibrated every few hours with the cuff during setup to prevent readings from constantly being higher or lower than they should be?
Blood pressure tracker and app
- Blood pressure data is averaged every two hours
- Calibration is required while seated
- Aktiia app clearly displays all data
Aktiia automates blood pressure readings. Except for this monthly calibration using the armband and a fortnightly recharge of the wristband for a few hours, it requires no maintenance and you won’t even notice it.
So what East does it really do? The blood pressure reading consists of two pressure numbers expressed in millimeters of mercury (mmHg); systolic (how hard your heart pumps blood); and diastolic (the resistance to blood flow in blood vessels). Aktiia uses its armband and the bracelet’s PPG sensor to take measurements at exactly the same time to calibrate the latter and increase the accuracy of its algorithm. It’s not something you get with a smartwatch (such as the Samsung Galaxy Watch Active 2) that claims to do something similar.
Calibrating the bracelet to the cuff is important because the arteries are narrower in the wrist than in the upper arm, so blood pressure readings tend to be higher and less accurate. Cue Aktiia algorithm. It’s hard to say exactly how accurate its results are, but it was “recommended for blood pressure measurement in the adult population” in one trial.
In our testing, our blood pressure readings – which are all taken when the wearer is at rest and displayed very simply in Aktiia’s streamlined app – were all consistent and thankfully all within the normal range.
Open the app and it syncs with the bracelet, taking about a minute to do so and aggregate all your data in the cloud. Within seconds, you see an updated number for your average blood pressure and a graph showing your average systolic and diastolic readings for each two-hour period for each day.
Although there is not a lot of data analysis, it is immediately obvious that blood pressure varies throughout the day and night, so the average is useful. It also gives a daytime average and a nighttime average with a reassuring message (“Your blood pressure was in range 100% of the time, great job!”) and a calculation and commentary on your resting heart rate. Importantly, you can then generate a simple PDF report to show your doctor that sums it all up.
Aktiia’s app is simple, easy to understand and convenient, although we think it should be linked to other fitness-focused apps, such as Apple’s Health app. We’re also aware that we had to manually enter our daily bedtime into the app, which may have tricked the device into measuring our blood pressure while we were still awake and moving.
- Proprietary Charger
- Lasts about two weeks
- The armband and wristband charger uses micro USB
With no screen to power and barely any functions except for that flashing optical PPG, the Aktiia is not a power-hungry device. The manufacturer says it lasts about a week, but after 10 days the battery was down to about 30%, which was impressive. It took about an hour to charge it to 100%.
Although the armband recharges using a micro USB port, it is rather disappointing that the bracelet has to be recharged on a small proprietary charging base. It’s not a huge device, measuring 34mm in diameter, but it could easily get lost. It connects to power using a micro USB cable. Given the proliferation of USB-C, we’d rather see this used on both the charging pad and the armband in the second generation Aktiia.
First revision in March 2022