Barostat
A barostat is a device used to maintain constant pressure in a closed chamber.<ref name="Leszczynski2011">Template:Cite book</ref> Its main principle is providing constant pressures in a balloon by means of a pneumatic pump.<ref name="HinchcliffKaneps2008">Template:Cite book</ref> Barostats are frequently used in neurogastroenterology research, where they are used for measuring gut wall tension or sensory thresholds in the gut.<ref name="EmmanuelQuigley2013">Template:Cite book</ref>
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.
Barostat-balloon systems have been used anywhere in the gut, including the esophagus,<ref name="SchusterCrowell2002">Template:Cite book</ref> stomach,<ref name="Said2012">Template:Cite book</ref> small bowel,<ref>Template:Cite book</ref> colon, and the rectum ampulla.<ref name="AltomarePucciani2008">Template:Cite book</ref>
Computer-driven barostats have widely been used to assess sensation and pain thresholds in the gut. Assessment of pain thresholds in the ampulla recti has been proposed as diagnostic measure in irritable bowel syndrome.<ref name="Fishman2012">Template:Cite book</ref><ref name="CamilleriSpiller2002">Template:Cite book</ref>