How Accurate Is the Aktiia Blood Pressure Monitor?

Monitoring blood pressure, a key health parameter, has traditionally required bulky equipment, trained medical personnel and been confined to clinical settings. Plus, it usually takes place only when other health concerns come to light or at irregular times often with long intervals in between. As a result, it’s a neglected and silent narrator of overall health and wellbeing.

Times – and technologies – are changing. Increasingly, people monitor their blood pressure at home. Commonly, this is done using commercially available cuff devices, either on the upper arm or the wrist. But they don’t always generate the data that’s needed – an accurate, aggregated and regular supply of blood pressure readings that physicians can rely on to make diagnoses and manage treatments.

Wearable technology is now at the forefront of healthcare innovation. It is helping to make efficient use of healthcare resources and leading to more precise management of a variety of conditions with better patient outcomes – in particular for hypertension (high blood pressure) thanks to personalised recommendations.

This article focuses on the Aktiia bracelet and app – and how together they’re making blood pressure monitoring more accurate, convenient and accessible. Worn unobtrusively on the wrist, the device is ideal for use both day and night (we’ll press snooze and come back to that) to provide a consistent data stream on an individual’s blood pressure.

As with any new technology, the million-dollar question is: how well does it perform? That’s especially true for medical devices. And in the case of the Aktiia solution, just how accurate, reliable and effective is it? With that in mind, let’s learn more about the technology it uses for blood pressure readings and the regulatory testing and validation it has undergone. Also, highlighting some real-world user experiences.

How Does the Aktiia Blood Pressure Monitor Achieve Accurate Readings?

Aktiia’s Optical Blood Pressure Monitoring (OBPM) technology uses optical sensors to gather photoplethysmographic (PPG) signals from the arteries in the wrist.

The shape of the PPG waveform contains information about blood pressure, and the OBPM algorithm strips out the ‘noise’ to turn these signals into systolic (pressure when the heart beats) and diastolic (pressure when the heart rests between beats) readings, along with resting heart rate.

The accuracy of blood pressure monitors is validated under the ISO 81060-2 standard, which stipulates that a product must be tested against a trusted reference device: examples include an arterial line, an arm cuff and a stethoscope, and a volume clamp on the finger. Aktiia’s clinical trial showed that its solution performed within the ISO accuracy standards for systolic and diastolic measurements, and for measurements taken in multiple body positions. It was also awarded CE Mark as a Class IIa medical device in December 2020.

Accuracy With Calibration

Setting up and maintaining the Aktiia device is key to accurate readings. Its measurements are synchronised with readings from the reference device, so the electronic upper arm cuff with Bluetooth is included in the box. Aktiia is the only company with this amount of data from both optical and cuff readings. The monthly synchronisation ensures continued accuracy.

To understand why continuous blood pressure monitoring is important, it’s worth comparing the method to traditional, inconsistent monitoring in clinical settings. Traditional cuff-based blood pressure monitors, while widely used, have their limitations and potential sources of error which could lead to inaccurate readings, including:

• White Coat Syndrome: Some individuals experience elevated blood pressure readings in clinical settings due to anxiety or stress, even if their blood pressure is typically normal at home.
• Cuff size and positioning: Fit and positioning of the cuff can significantly influence the accuracy of the readings. An ill-fitting cuff or one that’s improperly positioned can result in readings that are either too high or too low.
• Intermittent readings: As blood pressure naturally fluctuates throughout the day and is influenced by various factors, a single reading might not accurately reflect an individual’s overall blood pressure health and takes into account what happens to your blood pressure during the night and a phenomenon known as the ‘morning surge’.
• Irregular heart rhythm: In people with arrhythmias or irregular heart rhythms, cuff-based devices may not accurately capture blood pressure.

The primary advantage of continuous monitoring is the ability to capture a comprehensive view of an individual’s blood pressure throughout the day and night. Unlike intermittent readings, the Aktiia bracelet provides a more detailed picture of blood pressure patterns and fluctuations. These can help health professionals make more informed decisions about treatment plans and lifestyle recommendations.

Accuracy Through Aggregation

Consider your driving habits when passing through a stretch of road monitored by speed cameras versus an average speed check zone. This scenario helps to draw a line between traditional cuff-based monitors and Aktiia’s continuous measurement approach.

Speed cameras, like cuff devices, capture a snapshot of your driving speed at a single point in time. However, this might not accurately represent your driving norms. For instance, you might slow down upon noticing the camera and speed up again once you’ve passed it (of course, we’re certain you never do that). The point is, this one-off measurement may not reflect your typical driving speed, much like how a single blood pressure reading may not truly represent your overall blood pressure health.

On the other hand, average speed check systems, like Aktiia’s device, monitor your speed over a longer distance or period. This gives a more representative sample of your driving behavior. These systems calculate your average speed between two points, averaging your speed to offer a rounded, more meaningful view of your driving.

Similarly, Aktiia’s continuous blood pressure monitoring allows for the 24/7 capture of blood pressure variations, providing a more nuanced and accurate understanding of your blood pressure. Plus, it can level out a host of factors that can affect your readings throughout the day – particularly around eating, drinking or smoking habits.

Accuracy Plus Convenience

In everyday use, reviews suggest the Aktiia combination of device and app work well together. The app helps visualise blood pressure readings, which in turn can motivate lifestyle changes – what we call ‘the Aktiia effect’. It tracks changes over time and helps make sense of the data, so blood pressure monitoring quickly becomes a routine part of daily life.

In addition, the optical signals from the bracelet are checked by the app before being processed and returned by Aktiia’s cloud-based algorithms. This helps to ensure that only trusted, validated data is displayed. If regularly synchronised, the app quickly updates with the latest data, offering near real-time access to blood pressure information. And even if users don’t sync regularly, the bracelet has enough memory to store 30 days of sensor data.

However, no device is infallible, and Aktiia is continuously evolving and improving the product. In the future, calibration may not be required. And as highlighted in some reviews, readings from Aktiia may occasionally vary, although the deviation is within acceptable limits. This underlines the importance of using the Aktiia bracelet or any blood pressure monitoring device as part of a comprehensive health strategy that includes regular check-ups with healthcare professionals.

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Conclusion: Accuracy That the Future of Healthcare Can Rely On

To sum up, the Aktiia blood pressure monitor is helping to reshape approaches to blood pressure monitoring. Its accuracy has been rigorously tested to meet international standards. By adopting continuous monitoring, it can offer a more comprehensive, nuanced, aggregated and accurate view compared to traditional methods. With the easy-to-use Aktiia device and app, patients can take proactive control of their health, improve disease management and their quality of life. So, as we move towards an era of personalised, connected and digitised healthcare, devices like the Aktiia solution will play an increasingly pivotal role.

Disclaimer: If you have hypertension and you plan to start blood pressure exercises, we encourage you to speak to your healthcare professional.

Sources

The Evidence Behind Aktiia, 2023 – https://aktiia.com/evidence

How Accurate is Aktiia? Aktiia Support, 2023 – https://support.aktiia.com/support-articles-how-accurate-is-aktiia

Aktiia Blood Pressure Monitor Review, Basic Tutorials, 2023 – https://basic-tutorials.com/gadget-reviews-aktiia

Blood pressure from the optical Aktiia Bracelet: a validation study, Blood Pressure Monitoring, 2021 – https://journals.lww.com/bpmonitoring-blood-pressure-from-the-optical-aktiia-bracelet

Aktiia’s wrist-mounted blood pressure monitor gains CE mark, Cardiovascular News 2020 – https://cardiovascularnews.com/aktiias-wrist-mounted-blood-pressure-monitor-gains-ce-mark

Validating the Accuracy of the Aktiia Blood Pressure Monitor, Nature 2023 – https://www.nature.com/articles-s41598-021-99294-w

Evaluation of a Novel Wearable Optical Blood Pressure Monitor, PubMed Central, 2023 – https://www.ncbi.nlm.nih.gov/articles-PMC9981319

Aktiia 24/7 Blood Pressure Monitor Review: Stalking the Silent Killer, ZDNet, 2023 – https://www.zdnet.com/article-aktiia-247-blood-pressure-monitor-review-stalking-the-silent-killer