Intravenous system having an accumulator tube therein

Claim 1

In an intravenous administration set of the gravity flow type having a flow blockage alarm means and including a length of flexible intravenous tubing and a cannula connected therewith for insertion into the vein of a patient to deliver a fluid to the patient, the improvement comprising: means for temporarily storing a predetermined maximum volume of fluid during a temporary flow stoppage so that after removal of a temporary blockage the stored volume of fluid is delivered to a patient such that a proper volume of fluid can be delivered to a patient without actuating any alarm means associated with the intravenous administration set during such temporary fluid stoppage, said means including a housing means connected inline with the intravenous tubing, said housing means including a wall, an expansible accumulator tube connected inline with the intravenous tubing and being located within the housing means and during normal operation comprising a part of the flow path for fluid being delivered to a patient, said expansible accumulator tube being spaced radially inward from said housing means wall throughout substantially the entire length of said accumulator tubing to define an annular space, said annular space defining an expansion volume, said accumulator tubing expanding against said housing means wall throughout substantially the entire length of said accumulator tubing and accumulating a predetermined volume of fluid when flow through the cannula is blocked or restricted, so that when the blockage or restriction is removed, the accumulated volume of fluid is automatically delivered to the patient from the expanded accumulator tube, said expansion volume being sized such that the accumulator tubing will accommodate only a predetermined maximum volume of fluid therein so that excessive delivery of fluid in a short amount of time to a patient is not possible.