a)	Measuring airway size
                    
                    
                i)	Leak testing video (rigid)
                
                    b)	Oxygen insufflation as a probe
                    
                
                
                    c)	BAL techniques
                    
                
                
                    d)	Endoscopic documentation of mucociliary transport function
                    
                
                
                    e)	Evaluation of endotracheal tubes
                    
                
                
                    f)	Technical tips
                    
                      
                
            