Mechanical auxillary ventricle blood pump with reduced waist portion

An apparatus for assisting cardiac function during a cardiac cycle of a patient when positioned with respect to an aorta, the apparatus comprising:

• an elongate semi-rigid shell having a contoured, concave inner surface terminating at a peripheral side edge;
• at least one passage extending through the shell to define an opening in the inner surface;
• and
• an elongate, flexible membrane connected to the shell adjacent to the peripheral side edge and defining an enclosed inflatable chamber in fluid communication with the passage, said membrane having a centrally located higher tension zone adjacent the opening of the passage through the shell where tension decreases with respect to distance from the at least one passage to prevent occluding the entrance while deflating the chamber.

A dynamic aortic patch having a flexible membrane and manufactured according to a method including the steps of providing an elongate mandrel having a shape defined by substantially flat major surfaces opposite one another and terminating at a rounded peripheral side edge extending between the major surfaces, the side edge contoured and curved to define partial ellipses at both ends and a reduced waist portion adjacent a midway portion, placing a thin, flexible, heat setable, membrane over one of the flat major surfaces and wrapped around the side edge a sufficient distance to form a flange adjacent the opposite flat major surface, holding the membrane in place on the mandrel with at least one clip, and heating the membrane sufficiently to set in memory of the membrane a shape of the mandrel, the dynamic aortic patch comprising:

• an elongate semi-rigid shell having an inner surface terminating in a peripheral side edge and at least one passage extending through the shell to define an opening in the inner surface;
• and
• an elongate, flexible membrane connected to the shell adjacent to the peripheral side edge and defining an enclosed inflatable chamber in fluid communication with the passage, said membrane having a centrally located higher tension zone adjacent the opening of the passage through the shell where tension decreases with respect to distance from the at least one passage to prevent occluding the entrance while deflating the chamber.