Pressure actuated flow control valve

A method of controlling fluid flow in opposite infusion and aspiration directions through an intravascular device including a catheter, the method comprising the steps of:

• providing a pressure-actuated valve component for use in IV therapy, said valve component comprising:
• a housing including spaced apart intravenous fluid ports operable to be fluidly coupled to the catheter, with a fluid passageway extending between the ports to present a passageway axis, and
• a valve body being disposed within the fluid passageway and including a flexible dome-shaped wall that presents a convex surface and an opposite concave surface, with the convex surface facing the infusion direction and the concave surface facing the aspiration direction,
• said dome-shaped wall including a slit extending between the surfaces,
• said dome-shaped wall flexing to open the slit in response to an infusion fluid pressure differential across the wall, wherein the pressure against the concave surface is greater than the pressure against the convex surface,
• said dome-shaped wall flexing to open the slit in response to an aspiration fluid pressure differential across the wall, wherein the pressure against the convex surface is greater than the pressure against the concave surface,
• said valve body including a rib projecting from the concave surface in a generally orthogonally extending relationship to the slit;
• fluidly coupling the valve component with the catheter;
• manipulating the intravascular device to introduce a forward fluid flow through the valve component to create said infusion fluid pressure differential across the dome-shaped wall, such that upon a pressure against the concave surface of the valve wall being approximately greater than a predetermined fluid cracking pressure of the valve wall, said slit flexing distally to open;
• terminating the forward fluid flow through the valve component, such that upon the pressure against the concave surface dropping below the predetermined fluid cracking pressure, the rib serves to bias the slit proximally into a closed, flow-blocking position;
• and
• manipulating the intravascular device to introduce a rearward fluid flow through the valve component to create said aspiration fluid pressure differential across the dome-shaped wall, such that upon a pressure against the convex surface of the valve wall being approximately greater than a predetermined fluid collapsing pressure of the valve wall, said slit flexing proximally to open,
• wherein upon the slit flexing proximally to open, a limited portion of the dome-shaped wall flexes proximally, and the entire dome-shaped wall does not invert proximally,
• wherein the rib serves to bias the slit distally into said closed, flow-blocking position.