The problem with high blood pressure is that it often goes undiscovered in those that suffer from it. Diagnosing it can be hard, as it traditionally involves wearing a pressure monitor for a day of arm-squeezes. Enter the wristband from the Swiss start-up Aktiia.
Around a third of all adults have high blood pressure. This so-called ‘silent killer’ is projected to affect at least 1.5 billion people globally by 2025.
For some people with a very pronounced risk profile, the detection of high blood pressure is particularly important.
This can be, for example, elevated cholesterol levels, diabetes or a family history of heart disease. In these patients, 24-hour blood pressure measurement may be necessary.
They are more likely to have a heart attack or stroke. Or they could be one of the millions affected by occlusive peripheral arterial disease.
With its wristband, the Swiss start-up Aktiia wants to make it possible for anyone with €200 (RM994) to spare to monitor their blood pressure around the clock over a longer period of time.
The classic method of measuring blood pressure 24 hours a day is very stressful for patients: every 15 minutes, the cuff on your upper arm inflates, pinches off the blood flow and the blood pressure is measured.
At night, the device turns on every half hour. However, these measurements won’t be taking place every day, only occasionally to check the blood pressure.
There’s an entirely different technique with the Aktiia wristband, meanwhile, which looks like a simple fitness tracker.
With the so-called pulse wave analysis, optical signals on the wrist of the patient are processed and the blood pressure is estimated quite accurately.
In the process, the wristband glows with green light on the inside to determine how the arteries pulse under the surface of the skin.
This procedure is also known from heart rate monitors or smartwatches with a heart rate monitor. However, the Aktiia device not only counts the heartbeats, but also examines the pulse formation with artificial intelligence.
The method was developed over 15 years by a team around the researchers Mattia Bertschi and Josep Sola at the tech centre CSEM (Centre Suisse d’Electronique et de Microtechnique) in Switzerland.
But the wristband can’t work entirely without traditional measurement technology: It has to be calibrated before the first use and then once a month with the enclosed cuff measuring device.
In our test, we found this to be a bit of a weak point. The calibration between the reference cuff and the wristband proved to be very fiddly and only succeeded after several attempts.
At least you have a month of peace after a successful calibration. The wristband can be worn for over a week at a time because it only needs to be recharged every nine days.
The Aktiia system includes an app that establishes contact with the cuff and the wristband via Bluetooth. In the application, you can see your blood pressure over the course of the day. You can also compile weekly or monthly reports, which you can export as a PDF for a doctor’s visit.
Unfortunately, Aktiia does not allow you to export the raw data in a table or send readings to the health apps from Apple and Google to display it in a larger context with other data such as body weight.
In the daily overview, it is noticeable that every now and then an entry in the two-hour measurement period is missing. That’s because the Aktiia wristband only measures blood pressure at rest. When you’re physically active or moving your wrist lots, the measurements pause.
The Aktiia wristband, which does not feel very high-quality, is far from cheap at €200 or £160 (it’s currently shipping online in Western Europe). For comparison you can pick up a top-rated conventional blood pressure monitor for a fifth of that price.
But remember: With conventional devices, you won’t get quite the same undisturbed sleep if you want blood pressure values at night. – dpa