A method for cleaning the lens of a visualization device integrated into a ventilation tube positioned inside a patient, wherein the tube comprises a ventilation lumen and the lens is positioned proximal to the distal end of the ventilation lumen, the method comprising providing a suction catheter comprising a brush at its distal end； positioning the catheter inside the ventilation lumen such that the brush protrudes from the distal end of the ventilation lumen； and manipulating the catheter at its proximal end to cause the brush to make contact with the lens in order to clean the lens.
