Patent ID: 7662181

Claim:
A method for treating a patient's lung, the method comprising: attaching a flow control element to a distal region of a delivery catheter, wherein the flow control element includes a seal member, a frame within the seal member, and a duckbill valve inside the frame; delivering the distal end of the delivery catheter and the flow control element through the patient's trachea into a bronchial passageway; detaching the flow control element from the distal region of the catheter in the bronchial passageway in the lung so that the flow control element seals with an interior wall of the bronchial passageway, wherein the flow control element restricts fluid flow in at least a first direction through the bronchial passageway but does not completely block flow in the first direction when the flow control element is in a closed state; and delivering a therapeutic substance into the bronchial passageway at a location distal of the flow control element, wherein the therapeutic substance is delivered prior to deploying the flow control element.