Valve gasket and hemostasis valves and cannula units incorporating the same

A hemostasis valve, comprising:

• a first valve gasket, comprising:
• an annular wall;
• a plurality of ligaments attached to and extending radially inward from the annular wall, wherein each ligament of the plurality of ligaments includes a ligament slit that divides the ligament into two ligament segments;
• and
• a membrane surrounded by the annular wall and attached to the plurality of ligaments and to the annular wall, wherein the membrane includes at least one membrane slit that divides the membrane into a plurality of flaps,
• wherein the plurality of ligaments are positioned with the plurality of ligament slits aligned with the at least one membrane slit, such that each flap is bounded along a circumferential edge by the annular wall, along a first radial edge by a first ligament segment, and along a second radial edge by a second ligament segment;
• and
• a second valve gasket, comprising:
• an annular wall;
• a plurality of ligaments attached to and extending radially inward from the annular wall, wherein each ligament of the plurality of ligaments includes a ligament slit that divides the ligament into two ligament segments;
• and
• a membrane surrounded by the annular wall and attached to the plurality of ligaments and to the annular wall, wherein the membrane includes at least one membrane slit that divides the membrane into a plurality of flaps,
• wherein the plurality of ligaments are positioned with the plurality of ligament slits aligned with the at least one membrane slit, such that each flap is bounded along a circumferential edge by the annular wall, along a first radial edge by a first ligament segment, and along a second radial edge by a second ligament segment,
• wherein a rear surface of the first valve gasket is placed against a rear surface of the second valve gasket with the membrane of the first valve gasket pressed against the membrane of the second valve gasket.

A valve gasket, comprising:

• an annular wall;
• and
• a sealing assembly disposed within the annular wall, the sealing assembly comprising:
• a central protrusion;
• a plurality of ligaments connected to the central protrusion, wherein each ligament of the plurality of ligaments extends radially away from the central protrusion towards the annular wall and is connected to the annular wall;
• a membrane connected to the central protrusion, to the plurality of ligaments, and to the annular wall;
• and
• at least one slit through the membrane, the central protrusion, and the plurality of ligaments, wherein the at least one slit separates the sealing assembly into a plurality of valve flaps, wherein each valve flap of the plurality of valve flaps is bounded on an outer circumferential edge by the annular wall, on an inner circumferential edge by the central protrusion, on a first radial edge by a first ligament of the plurality of ligaments, and on a second radial edge by a second ligament of the plurality of ligaments.