alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation alveolar ventilation