Patent ID: 8776818

Claim:
A method of regulating the flow of fluid through a passageway comprising: positioning a flexible membrane member in said passageway; positioning a drive screw member inside said flexible membrane; said drive screw member being attached to said flexible member by a threaded sleeve member powered by the drive screw member and positioned at the distal end of said drive screw member, said threaded sleeve member being fixedly secured to said flexible membrane, and positioning at least one anti-rotation member connected to the threaded sleeve member for preventing rotation of said flexible membrane and the threaded sleeve member relative to said drive screw member; connecting an electric motor actuator to said drive screw member; actuating said electric motor to rotate said drive screw member around its longitudinal axis in order to effectuate radial expansion or contraction of said flexible membrane; rotation of said drive screw member in one direction moves said threaded sleeve member towards said electric motor and radially expands a mid-portion of said flexible membrane restricting flow of a fluid through said passageway, rotation of said drive screw member in the opposite direction retracts said mid-portion radially to a second position allowing flow of fluid through said passageway; wherein flow of fluid through a passageway can be metered.