Flow regulating device for arterial catheter systems

Claim 1

A flow regulating device which provides a continuous regulated flow of a medical fluid to an intravenous catheter system used in monitoring arterial functions and in the infusion of medical fluids to an artery or vein, and which also provides for an intermittent, manually controlled, larger flushing flow of fluid to the catheter system, said device comprising a control member having an inlet means adapted to be connected to a source of a medical fluid and an outlet means adapted to be connected to an intravenous catheter; a first passage connecting said inlet and outlet means for fluid flow communication therebetween, said first passage at least in part comprising a section of flexible conduit fitting coaxially over a cylindrical, hollow extension which extends from said outlet means to about the midsection of said flexible conduit; valve means comprising a substantially cylindrical plug member positioned coaxially within said flexible conduit and having a flexible conduit engaging portion around the plug member intermediate its ends, said flexible conduit engaging portion being positioned adjacent to the extending end of said cylindrical, hollow extension, said flexible conduit engaging portion also being of sufficient diameter to form a substantially flow tight seal with the interior wall of said flexible conduit when the flexible conduit is not being deformed, so that fluid cannot flow around said plug member, and whereby when said flexible conduit is deformed, it creates flow channels extending across the flexible conduit engaging portion on said plug member, so that said larger, flushing flow of fluid can flow around said flexible conduit engaging portion on said plug member and through said first passage; and a second passage by-passing said valve means and connecting said inlet and outlet means, said second passage containing flow restriction means which limits the flow of fluid therethrough, under a given pressure, to a desired amount.