A sphygmomanometer is an instrument for measuring blood pressure in the arteries, consisting of an inflatable cuff that wraps around the upper arm and inflates to constrict the arteries and a gauge (mercury or mechanical manometer) to measure the pressure. The device was invented by Samuel Siegfried Karl Ritter von Basch in 1881. In 1901, Harvey Cushing modernized the device and popularized it within the medical community.