JANUARY 27TH, 2021 SCOTT JUNG CARDIOLOGY, GERIATRICS, MEDICINE
Swiss company Aktiia, whose cuffless blood pressure monitor we’ve been following for several years, announced that their wrist-worn device has received the CE Mark as a Class IIa medical device in Europe, and is now available for pre-order in the UK through the Aktiia website.
Aktiia recently completed a pivotal trial whose preliminary results suggest that the device was able to meet a requirement of less than 5 mmHG mean difference (<8 mmHG standard deviation) between its readings and a reference measurement using double auscultation over a period of one month.
A couple of years ago we spoke with Josep Sola, the CTO of Aktiia, who explained the workings of the device’s blood pressure detection algorithm as follows:
Basically, you have the heart valve which opens and closes. Once it shuts, you have the same effect as a water handler/pipe. It’s like when you have a water hose with a valve that you abruptly shut off, there’s a wave that goes backwards. You similarly have a wave that comes out of the arterial system. The heart propels fluid, then the valve shuts, and the “water hammer” goes backwards and the wave propagates on the walls of the artery. Because the vessels branch at certain areas, the wave goes backwards.
We use a standard optical sensor for HR monitoring and we look at what the waves do. Using pulse wave analysis, we can identify fingerprints of the blood pressure, then modulate the signal in a way that we can derive exact blood pressure signals. Depending on the blood pressure, these waves change. So do the times of the waves.
In addition to the device itself, the kit comes with access to a smartphone app and an initialization cuff, meaning it appears you’ll have to calibrate the device at least once. But the release of Aktiia is huge progress in the ability to measure blood pressure without squeezing your limbs, something that has been a long sought goal of medicine.
The device is still awaiting FDA clearance, and we’re eager to have it available here in the U.S.!
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