In 1896, Riva-Rocci, an Italian physician, first described the mercury sphygmomanometer. It consists of an inflatable cuff, an inflating bulb, and a mercury column to read the pressure.

For accurate reading:

• The mercury column should be vertical, otherwise the reading can be inaccurate
• It should be regularly checked, and when not in use the top of the mercury meniscus should read zero
• The air vent at the top of the manometer must be kept patent

This device is rarely used in current clinical practice, due to concerns about mercury toxicity and the availability of automated devices.