Patent ID: 8795198
Filing Date: 2014-08-05
Classification: A61B

Abstract:
1. A needle assembly comprising: a housing defining a housing interior; a cannula having a first puncture tip extending from a first end of the housing; a second puncture tip extending from a second end of the housing, the second puncture tip and the first puncture tip being in fluid communication with each other through the cannula, wherein the sole communication path between the housing interior and the external environment is via the first puncture tip; and a porous vent positioned within the housing interior to separate the housing interior into a first chamber and a second chamber, the porous vent positioned in a manner such that the first chamber has a volume of 5 percent to 20 percent of a total volume of the housing interior with the cannula being in fluid communication with the first chamber, the porous vent including pores extending therethrough to provide a fluid path between the first chamber and the second chamber, such pores adapted for passage of fluid at least partially into the porous vent without sealing of the pores, wherein the second chamber comprises at least a first interior region and a second interior region, the first interior region and the second interior region separated from each other by the porous vent and in fluid communication with each other through the porous vent.