US Patent 9050401 System for controlled delivery of medical fluids

A system for controlled delivery of medical fluids to a patient includes an inlet conduit attached to a source of a medical fluid and an outlet conduit connected to the patient. The inlet and outlet conduits are interconnected by a multiple stage control valve assembly and a pair of syringes. The control valve assembly is alternated between a first state wherein the inlet conduit communicates with a first syringe for transmitting fluid from the source to the first syringe, a second state wherein the first syringe communicates with a second syringe and is isolated from the inlet conduit and the outlet for transmitting fluid from the first syringe to the second syringe, and a third state wherein the second syringe communicates with the outlet and is isolated from the inlet and the first syringe for transmitting fluid from the second syringe to the patient through the outlet.