Aorta cannula for low flow rates used in heart operation

摘要

At the proximal end (22) of the cannula (20) is a conventional tube connector for connection to the blood circuit. The distal end (34) has an end piece (30) for insertion into the aorta for supplying blood or other fluids during an operation for example. The side wall of the end piece is made from an elastic flexible material with a hardness of between 50-80 Shore-A. In the side wall are several spiral shaped slots (42) formed in a clockwise orientation. When fluid pressure in the cannula increases an axial component of pressure acts on a cap (34) at the end of the end piece causing slight deflection of the end piece which widens the slots which reduces the exit velocity of fluid from the cannula.