Obtaining blood sample using cannula and evacuated vessel - having adjustable flow valve and second valve on cannula

摘要

A blood sample is obtd. by a cannula which extends from a housing including a first valve normally obstructing a discharge port leading to the cannula. An evacuated vessel includes a valve mounted within its neck and operable by rotating the container w.r.t. a conduit extending axially from the neck. This conduit can enter the discharge port of the cannula housing to provide a fluid-tight connection but also simultaneously opening the first valve to allow connection between the cannula and container valve. The appts. is used to obtain a blood sample by first inserting the cannula into a blood vessel then attaching the container with its valve still in the closed condition. The valve is then opened and blood enters the container. Evacuated containers can be used sequentially by coupling into the cannula and the first valve automatically seals the blood discharge between connections. The flow valve associated with each container can be opened partially to test whether the cannula has correctly entered a blood vessel and if unsuccessful the valve can be closed immediately to prevent the formation of a haematoma.