Patent ID: 6030335
Filing Date: 2000-02-29
Classification: A61M

Abstract:
An implantable heart-assist pump of the back-pressure balloon type, the pump comprising:an essentially rigid body (10) open at both ends (12, 14) and designed to be inserted in the down aorta artery (16);a flexible and elastic membrane (18) in the form of a sleeve connected in sealed manner to the body at the periphery of the ends thereof so as to define firstly, between the body and the sleeve, a closed intermediate space (20) of variable volume, and secondly, inside the sleeve, a variable volume (22) through which the blood to be pumped passes; andmeans for connecting the intermediate space to a source of hydraulic fluid (28) suitable for causing the membrane to pass from a free state to a tensioned state in which it is urged radially inwards, thereby correspondingly reducing the volume through which the blood passes, and vice versa;the pump being characterized in that:between the ends of the body, the membrane is freely movable relative to the body; andthe membrane has at least three longitudinal stiffener elements (36) uniformly distributed around the periphery of the membrane, said stiffener elements being suitable for locally reducing the longitudinal elasticity of the membrane, imposing a star-shape to the right section of the membrane in the tensioned state, which shape develops progressively between each end region and the middle region, said star-shape leaving a residual volume without the membrane coming into contact against itself.