anal fistula (fistula in aÂ´no) one opening on the cutaneous surface near the anus, which may or may not communicate with the rectum. arteriovenous fistula one between an artery and a vein, either pathologic (such as a varicose aneurysm) or surgically created to ensure an access site for hemodialysis.
1 millibar (or hectopascal/hPa), is equivalent to 0.02953 inches of mercury (Hg). It is therefore only necessary to multiply a reading in millibars by the latter figure, to achieve the required conversion. E.g. for 1023 mbar, multiply by 0.02953=30.21 inches.
Atmospheric pressure is also known as barometric pressure because barometers are used to measure it. The National Weather Service reports air pressure in both inches of Mercury (inHg) and hectoPascals (hPa), also called millibars (mb). Air pressure measurement is considered to be static (little or no air movement). Inches of mercury refers to how high the air pressure pushes the mercury in barometers. In the metric system, the unit of pressure is the Pascal, named after the 17th century scientist Blaise Pascal. Pascals are a direct measurement of atmospheric pressure, like pounds per square inch.