Patent ID: 8905064

Claim:
A drug infusion flow regulating apparatus comprising: an inlet configured to receive liquid into the apparatus; an outlet configured to discharge the liquid from the apparatus; a cylinder assembly comprising a first cylinder, a second cylinder and a third cylinder that are arranged along an axial direction; the first cylinder comprising a first interior surface; a continuous helical thread formed into the first interior surface of the first cylinder; the second cylinder fitted into the first cylinder and comprising a second interior surface and a second exterior surface; a helical liquid-flow channel formed between the first cylinder and the second cylinder through the continuous helical thread, the helical liquid-flow channel being in fluid communication with the inlet; a plurality of longitudinal grooves extending along the axial direction and formed into the second cylinder on the side of the second interior surface; a plurality of through-holes formed in the second cylinder and in fluid communication with the helical liquid-flow channel; the third cylinder fitted into the second cylinder and comprising a third exterior surface; a plurality of independent liquid-flow passages formed between the second cylinder and the third cylinder, wherein each of the plurality of independent liquid-flow passages is in fluid communication with the helical liquid-flow channel via at least one of the plurality of through-holes; and a diaphragm valve configured to regulate fluid communication between the helical liquid-flow channel and the outlet.