The sphygmomanometer has endured as a doctor’s office staple for over 100 years. Just about every visit to a physician involves placing this inflatable cuff on your upper arm and having it squeezed tight to measure the force of blood pushing through your body. Surprisingly, noninvasive blood pressure measurement technology has advanced little, but now STBL Medical Research AG, with the assistance of engineers from the Swiss Federal Laboratories for Materials Science and Technology (EMPA) have designed a device to make blood pressure monitoring as simple as wearing a watch.
How did EMPA engineers manage to reduce an inflatable cuff down to a small bracelet? Instead of restricting blood flow, the “blood pressure watch” uses several sensors that measure the contact pressure, pulse, and blood flow on the surface of the skin near the wrist. This was no easy feat, especially when it came to accounting for the differences in pressure on the skin resulting from simply adjusting the bracelet on the wrist.
To overcome this, EMPA engineers developed a sensor made from piezo-resistive fibers in the wristband that measures the contact pressure of the device on the skin. When the device detects any movement or change in pressure, it converts the change into an electrical signal and transmits this to the measuring device, which then adjusts the blood pressure calculation accordingly.
Initial measurement tests of the blood pressure watch have been promising when compared to the catheterization procedure. In addition to being far less invasive and cumbersome than catheterization and even a sphygmomanometer, the blood pressure watch has the potential benefit of being a continuously monitoring device, which will help patients who tend to suffer from the “white coat” effect in which their blood pressure readings are abnormal due to nervousness around doctors. It has the potential of also being able to provide emergency alerts if one’s blood pressure ever reaches dangerous levels. It’s also said to cost far less than current continuous-monitoring blood pressure devices found in hospitals.
Article from EMPA: Wristband revolutionises blood pressure measurement
More info: STBL Medical Research AG website