Dr. Bertalan Mesko, PhD
5 min | 29 June 2023
Key Takeaways
From the first experiments in the 16th century, blood pressure (BP) monitoring has evolved tremendously, current devices can connect with our phones, allowing patients to record their readings and share them with their doctors
Companies like iHealth, Withings, and Viatom have even added extra features such as heart rate monitoring and the integration of BP and ECG monitors into single devices
With the use of photoplethysmography (PPG) devices became sleeker and lighter, and can continuously monitor blood pressure in real-time, which might make blood pressure monitoring as common as heart rate monitoring on wearable devices
The history of blood pressure monitoring originates in the 16th century from Sir Stephen Hales’ experiments involving directly inserting a tube in an artery. Since then, the practice has been (thankfully) improved not to involve invasive manoeuvres.
Nowadays, blood pressure monitoring is an essential part of a patient’s examination; and in the digital health era, the means to do so are evolving. In this article, we’ll consider the evolution of this practice and what awaits it in the future, as it might be the next healthcare practice most prone to change based on recent trends.
From manual to digital blood pressure monitoring
While the first instances of measuring blood pressure (BP) can be dated back several centuries, the practice with which we are more accustomed hails from the 20th century. This has traditionally involved a combination of an inflatable arm cuff, a stethoscope and a mercury-based scale. Over time, the need to manually inflate the cuff and listen through a stethoscope has been supplemented by digital means with slimmer devices that can be more easily used at home.
With the advent of digital health, BP monitors were coupled with smartphone apps to supplement the recording of readings so as to create a BP diary that patients can share with their doctor.
Some companies like iHealth, Withings and Viatom added even more features to digital blood pressure monitors. For example, the light and portable iHealth Clear not only measures BP but also heart rate; and the companion app converts the raw data into digestible information packages.
Others like the Withings BPM Core and the Viatom Armfit+ integrate both a BP and ECG monitor into a single device. They can both pair with a companion smartphone app to store the collected data. This allows patients to further analyse or share the results; thereby enabling them to better manage their condition at home.
The next step in the evolution of BP monitors would be to trim them down further to the form factor of a common wrist-worn device.
Blood pressure readings from the wrist – a first glimpse at the future
What was common with the aforementioned examples, whether analogue or digital, was that measurements were taken from the arm. MedTech company Omron presented something different when it announced the Omron HeartGuide in 2018.
The latter was a daring attempt at being the first-ever blood pressure smartwatch. Unlike other BP monitors, this wearable would take BP measurements from the wrist with cuffs integrated in the strap; and it even had FDA-clearance for blood pressure readings.
This represented a dramatic change from the century-old method … in concept. In practice, Omron’s take on BP monitoring from the wrist didn’t pan out so well. When we reviewed it, we found it to be bulky, cumbersome and not really practical to use.
The accuracy of these early attempts was influenced by factors such as physical activity and body temperature. Calibration also needed to be performed regularly with a traditional blood pressure monitor to ensure accuracy.
Considering these pitfalls, this wrist-based approach didn’t really pick up steam; but that wasn’t the final form of blood pressure monitors.
The cuff-less revolution and the future of BP monitoring
The Omron HeartGuide was only the first attempt at wrist-based BP monitors, and its issues were largely due to repurposing cuffs to fit into a smartwatch form factor. Newer approaches are more promising, especially with devices using photoplethysmography (PPG). PPG is a non-invasive optical technique that provides measurements based on changes in light intensity as a result of blood flow.
Adopting PPG sensors results in sleeker devices that are much more practical. They can further be more convenient as they can enable continuous, real-time BP readings; as opposed to one-off measurements at the doctor’s office.
For example, the Akita smart bracelet is lightweight and designed to continuously monitor blood pressure throughout the day. Its readings have even been shown to be comparable to traditional cuff-based BP monitors.
Other PPG-based devices like the BioBeat smart patch aim to monitor BP without visibly doing so. The sensor is applied through a skin patch on the body for reliable 24-hour monitoring.
By enabling BP measurements to be taken reliably, seamlessly and via less bulky devices, PPG-based monitors might represent the future of BP monitors. This evolution is an excellent showcase of how medical technology continues to progress to become more personal.
We could even see them become as common as heart rate monitors on smartwatches in the near future; further increasing access to monitoring one’s blood pressure. And when such devices make it to the market, we’ll be sure to report on, if not review, them.
Written by Dr. Bertalan Meskó & Dr. Pranavsingh Dhunnoo
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