| 摘要 |
A readily penetrable vacuum indicator closure for sealing an open end of an air evacuated blood collection tube. The closure comprises a flexible tubular body with an open first end and a closed second end formed by a penetrable, flexible end wall, with the end wall having an inner surface and an outer surface. When pressure on the inner and outer surfaces is substantially equal, the outer surface is convexly curved and the inner surface is concavely curved. This end wall is sufficiently flexible to deflect under the influence of a pressure differential on the end wall, such as may be perceived when the closure seals an evacuated blood collection tube. The outer surface of the flexible end wall is readily visible, thus serving as an indicator of relative pressures on opposite sides thereof. A flange is annularly disposed about the periphery of the tubular body adjacent to the second end. |
