Flow control device having selectable alternative fluid pathways

Abstract

A flow control device for use in a subcutaneously implanted physiological shunt system includes a relatively rigid base and a resiliently flexible encasement which defines a fluid flow path therethrough from an inlet to an outlet. Two valves for controlling the flow of fluid through the device are situated within the fluid flow path between the inlet and the outlet. The fluid flow path includes a first fluid conduit which directs fluid through both valves, and a second fluid conduit which bypasses the first valve and directs fluid only through the second valve. The first valve is constructed to provide a greater resistance to flow through the device than the second valve, and when the second fluid conduit is unobstructed, fluid will tend to flow through the second fluid conduit and bypass the first valve. A pivotable plug is provided within the encasement for selectively occluding a portion of the second fluid conduit. The position of the plug is determined by a magnetically polarized, percutaneously manipulable cam also provided within the encasement. The plug and the cam are attached such that rotation of the cam in one direction causes the plug to occlude the second fluid conduit, and rotation of the cam in another direction opens the second fluid conduit to fluid flow. A siphon control device is provided adjacent to the outlet to prevent fluid flow in response to negative downstream hydrostatic pressure on the outlet of the device.