Patent ID: 7955302

Claim:
A dosing device for an infusion system, the dosing device comprising a dosing unit, the dosing unit having a variable volume and a single opening into the variable volume, wherein the variable volume comprises a cylinder further comprising a piston, the piston being moveable in the cylinder in a first direction away from the single opening to increase the volume of the cylinder and in a second direction toward the single opening to decrease the volume of the cylinder; the dosing unit being operable in a first state to enable a substance to be supplied to the variable volume through the single opening, in a second state to prevent passage of the substance through the single opening, or in a third state to enable the substance to be dispensed from the variable volume through the single opening to a dispensing unit of the infusion system, wherein the dosing unit is operable to be rotated, displaced, or both, to select the first state, the second state, or the third state.