| 摘要 |
A multiple sample needle assembly for determining fluid access when collecting fluid samples from a source of fluid into a vacuum collection device. The assembly includes a housing with a chamber therein having first and second access openings in fluid communication with the chamber. The housing is preferably translucent to provide for the viewing of the contents of the chamber. A cannula is associated with the first access opening, while the second access opening is adapted for fluid communication with the vacuum collection device. An operable, resilient valve member is positioned in the chamber and is normally closed against a gas permeable, liquid impermeable plug member mounted in the valve member. This valve member is adapted to open away from the plug member when the pressure at the second access opening is less than the pressure at the first access opening. When the cannula makes entry into the fluid source, fluid enters the chamber by forcing any gas therein through the porous plug member with the fluid in the chamber being viewable by the user. This fluid is adapted to remain in the chamber until the valve member opens under the pressure differential. |
