Bmeasuring blood pressure with the smartwatch is the next big thing. The Apple Watch hasn’t mastered this yet. If Cupertino can do something like that, the technology has to work perfectly and reliably. But some watch manufacturers are already pushing ahead and offering solutions that may stutter a bit here and there, but are a plus for those users who have to measure regularly for medical reasons.
Samsung measures blood pressure for its Galaxy Watch watches using an optical photoplethysmogram sensor that records changes in blood volume. In order to determine the correct blood pressure, you have to calibrate the watch. You need an additional blood pressure monitor with a cuff and enter the result of the conventional measurement into the Samsung app. The whole thing is to be repeated three times and again after four weeks. You can then take the measurement with the watch alone, you have to sit still for around 30 seconds, the process is triggered manually.
The procedure works well, the values are correct. However, there is no way of continuously recording throughout the day like with a long-term meter that measures every 15 minutes. Such an option is offered by the Aktiia bracelet, which uses optical sensors to analyze the pulse waves of the arteries. Here, too, a conventional measuring device must be used for calibration. You don’t notice the measurement itself. However, you should know that an acceleration sensor determines the idle phases and only then measures them. It is measured continuously, but only the average values of two-hour intervals are displayed. Outliers upwards and downwards are therefore not recognizable.
Approved as a medical device thanks to the cuff
Now the Chinese manufacturer Huawei is entering the market with a blood pressure smartwatch. The Watch D for 400 euros is approved as a medical device, does not use optical sensors and does not require calibration, because the Chinese inventors have implemented something that is hard to believe at first: They have reduced the cuff of a conventional blood pressure monitor so that it fits between the arm and bracelet fits. The maximum measurement deviation is three millimeters of mercury. Respect, someone wanted to know.
The price of the complex mechanics is a certain effort of commissioning. You have to measure the wrist circumference and adjust one of the two enclosed bracelets exactly. The pressure cuff is then on the side of the arm facing the body and, since it is made of plastic, is protected by a removable fabric cover, which allergy sufferers will appreciate. Although the whole thing sounds complicated, the watch is quick to put on and comfortable to wear.
Convincing start for a quick blood pressure measurement
Blood pressure measurement has to be started manually, and Huawei points out that it requires a proper sitting position, straight up in a chair with your arm bent so that the watch is at heart level. If the software thinks it detects a deviation, it points to the correct sitting position. The measuring process is similar to that of a conventional measuring device. The cuff is inflated and then the pressure is slowly released. We compared it with a conventional, calibrated measuring device, and the accuracy of the watch is high. Anyone who measures blood pressure regularly knows that the values fluctuate. Overall, a convincing attempt when it comes to a quick blood pressure measurement. With the Watch D, for example, you can also conveniently measure in the office.
The measurements can be read in the Huawei Health app, which is available for Android or the iPhone. As a part-time job, the watch has all the talents that also characterize the manufacturer’s sports watches: up to 70 different sports are recorded and measured, with precise GPS and heart rate, oxygen saturation is determined, and a one-channel ECG can be used Write atrial fibrillation detection. The watch also shows push notifications from the smartphone, and the battery lasts for several days regardless of the mechanical inflation of the cuff. It should not be concealed that the Watch D with dimensions of 51 × 38 × 13.6 millimeters looks a bit clumsy. The AMOLED color display with 456 × 280 pixels, meanwhile, impresses with its brilliant, powerful display.