In-line sampling system incorporating an improved blood sampling device

Claim 1

A blood sampling system including a fluid line extending from a fluid supply to a patient, said system comprising an injection site entering the patient at a distal end of the fluid line, a fluid container disposed at the proximal end of the fluid line, a sampling site disposed proximally of the injection site, means enabling fluid flow from the fluid supply at variable rates, and a fluid storage mechanism interposed between the sampling site and the fluid supply to facilitate sampling, the fluid storage mechanism comprising: a main body portion having a longitudinal axis thereof generally aligned with the longitudinal axis of the fluid line; a concentric fluid draw element disposed within said main body portion in sealing relationship therewith and retractable along the longitudinal axis thereof; a fluid path provided through the fluid storage mechanism including a first fluid port provided in the main body portion; a fluid conduit provided in the fluid draw element extending from a distal end disposed adjacent said first fluid port to a proximal end thereof; and a vortex inducer element mounted at the distal end of the fluid conduit provided in the fluid draw element and having a fluid path therethrough, said vortex inducer element comprising a disk-like member having an upper surface and lower surface, the upper surface generally terminating at a point to conform its shape to the shape of the distal end of the main body portion of the fluid storage mechanism, and a lower surface including at least one groove radially extending from the center of the disk to an outer periphery of the disk, the groove spiralled from is central inner end to its radial outer end to induce a spiral flow of fluid from the distal end of the fluid conduit in the fluid draw element and into the fluid storage chamber of the fluid storage mechanism, with the fluid draw element retractable from a first sealed position, in which the main body portion receives the fluid draw element in a closed position of minimal fluid capacity to enable fluid flow from the fluid supply through the fluid conduit to the patient, to a continuously variable open position to enable withdrawal of blood and fluid into the fluid storage mechanism to assure withdrawal of blood only at the sampling site, and returnable to the closed position to return the fluids therein to the patient, with activation of the fluid flow means at a flush rate for cleansing blood and fluid from the fluid storage mechanism of the blood sampling system.