abstract:An endobronchial valve is an implantable medical device--a small, one-way valve, which is implanted in an airway in the pulmonary system to treat one of several lung conditions. The one-way endobronchial valve is typically implanted such that when a patient exhales, air is able to flow through the valve and out of the lung compartment that is fed by that airway, but when the patient inhales, the valve closes and blocks air from entering that lung compartment.