Breath-activated fluidic switch and method for drug delivery

Abstract

A drug inhaler of the type having an air jet entraining liquid medicine at an entrainment region from a medicine reservoir and nebulize or atomize entrained liquid by impacting a liquid medicine-laden air jet on a flat surface, and deliver the atomized medicine to a patient via a medicine delivery channel. A breath-activated fluidic switch has a power nozzle coupled to a source of air under pressure. The fluidic breath-activated switch has a pair of diverging legs, one of the diverging legs has a control port connected to sense inhalation of the patient, the other of the legs is coupled to the medicine entrainment region, whereby the entrainment of medicine at the medicine entrainment region is prevented by air supplied to the medicine entrainment region from the other of the legs in the absence of sensed patient inhalation at the control port. The fluidic control port is located downstream of the power nozzle a predetermined distance downstream of the wall attachment point.

Dependencies are inferred from the claim text.