Devices systems and methods are disclosed for preventing or inhibiting secretions from entering the lumen of a functional assessment catheter for the lungs, or removing collected secretions. The catheter comprises an expandable element, a cover, or an internal component configured to prevent or inhibit secretion flow into the lumen. The catheter alternatively or additionally comprises a distal end configured to facilitate air flow, absorb secretions or repel secretions away from the catheter tip. The catheter alternatively or additionally comprises an internal element such as a coilable wire, or an obturator configured to prevent secretions from being drawn into the lumen, or to actively remove the secretions. The catheter alternatively or additionally comprises an element to dry, aerate or aspirate the lung passageways.