| 摘要 |
A system is disclosed for preventing air from entering a first catheter or cannula of a multi-catheter system. Air is prevented from entering the proximal end of the first catheter by an axially elongate chamber having an impeller, the chamber being affixed to the proximal end of the first catheter. The first catheter is affixed at an offset location, near the periphery of the chamber. The impeller is driven by a motor drive and imparts rotational energy to the fluid within the chamber forcing any air within the chamber to migrate to the center of the chamber by buoyancy effects. The air is removed through a port near the centerline of the chamber. Liquid removed with the air is returned to the chamber to minimize liquid loss during the procedure. Hemostasis valves or seals can be provided at the entrance and the exit of the chamber. A second catheter inserted through the chamber and into the first catheter is unable to entrain gas into the first catheter because any gas that enters the chamber is routed to the centerline of the chamber where it is removed. The first catheter can be a cannula or an introduction sheath, devices suited for endovascular access into the mammalian cardiovascular system where pressures may fall below ambient room pressure, a condition, which could encourage the possibility of air embolism to a patient. Inflow of fluid from an external pump scrubs the second catheter shaft of air bubbles attached by surface tension.
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