The complications of infected lungs after surgery in the first 4 hours are the main causes of the collapsing at the positions belonging to lungs [54], [103]. 1.2.4 The strategy of reducing complications after surgery 1.3 The method of mobilizing alveolus 1.3.1 Definition 1.3.2 History 1.3.3 Methods of mobilizing alveolus * Mobilizing alveolus with the pressure +40 cmH2O Mobilizing alveolus with the continuous pressure 40 cmH2O in a period of 40 seconds.