A sphygmomanometer, also known as a blood pressure meter, blood pressure monitor, or blood pressure gauge, is a device used to measure blood pressure,
composed of an inflatable cuff to collapse and then release the artery under the cuff in a controlled manner,[1] and a mercury or mechanical manometer to measure the pressure.
It is always used in conjunction with a means to determine at what pressure blood flow is just starting, and at what pressure it is unimpeded.
Manual sphygmomanometers are used in conjunction with a stethoscope.
Etymology:
Greek sphygmos pulse (from sphyzein to throb) + International Scientific Vocabulary manometer, a device for measuring pressure
First known use: circa 1889
More info can be found at
https://en.wikipedia.org/wiki/Sphygmomanometer