the control of fluid introduction into and out of body conduits such as vessels , is of great concern in medicine . as the development of more particular treatments to vessels and organs continues it is apparent that controlled introduction and removal of fluids is necessary . fluid delivery and removal from such sites , usually referred to as irrigation and aspiration , using fluid exchange devices that control also need to be considerate of potential volume and / or pressure in the vessel or organ are described together with catheter and lumen configurations to achieve the fluid exchange . the devices include several electrically or mechanically controlled embodiments and produce both controlled and localized flow with defined volume exchange ratios for fluid management . the applications in medicine include diagnostic , therapeutic , imaging , and uses for the introduction or removal of concentrations of emboli within body cavities .