A barostat is a device used to maintain constant pressure in a closed chamber. Their main principle is providing constant pressures in a balloon by means of a pneumatic pump. Barostats are frequently used in neurogastroenterology research, where they are used for measuring gut wall tension or sensory thresholds in the gut.
A specially designed instrument is needed in neurogastroenterology research since the gut wall has an outstanding capacity to expand and contract spontaneously and by reflex. When this occurs, a balloon placed anywhere in the gut has to be inflated or deflated very rapidly in order to maintain a constant pressure in this balloon.