The measurement of blood pressure goes back almost three centuries, leading to the procedure that we all know and that our family doctor performs when we have checkups: A cuff (袖口) goes around our arm, which is first inflated (膨胀), and then deflated (放气), in a controlled manner, to determine our maximum and minimum blood pressure.
But the use of inflatable-cuff blood pressure monitors has some disadvantages. For one thing, unless people have home monitors, they must go to a chemistry shop, doctor's office or health center to learn what their blood pressure is. Another barrier is that repeated inflation and deflation of the cuff can cause difficulties when, for example, a patient is in the hospital and needs frequent blood pressure monitoring. And the last one is that since cuffs don't allow continuous measurement of blood pressure, they're only providing a measurement at a specific moment.
Today, a new generation of blood pressure devices have been developed and their aim is to make it easier to judge high blood pressure. Unlike traditional devices, they do without the arm cuff and offer blood pressure values on demand. Users just press their finger on a sensor on a watch and ring.
The various cuffless measuring devices are based on methods that, instead of directly determining blood pressure, use sensors to capture various indirect signals. These signals are processed by different sets of mathematical procedures to obtain the blood pressure values. It is like inferring fever by measuring an increase in heart beat and sweating instead of using a thermometer (体温表), or divining the result of a soccer match from outside the stadium by listening to the screams of the soccer fans.
The development of devices for measuring blood pressure without a blood pressure cuff is progressing rapidly, but that doesn't mean they are ready used to make diagnostic and treatment decisions. "The road to clinical application may be some day in the near future, but not now," Avolio says.
