US Patent 7037302 Positive flow needleless connector

The positive flow needleless connector has a cannula slideably mounted within a tubular housing. A sleeve-like septum seals the cannula from an outside environment while also sealing an internal chamber of the cannula from a flow path in a male luer housing. Movement of the cannula from an extended position to a retracted position against the force of a spring exposes a second inlet of the cannula to the flow path of the male luer housing to permit flow therebetween. During disconnect, the inlet from the cannula is sealed prior to the cannula returning the extended position. This allows fluid to move from a reservoir between the cannula and septum to move into the passage of the male luer housing.