Medical Science Technology

The mechanical properties of the respiratory system are important determining factors of their function and might be impaired in lung disease. Mathematical models are used for studying the physiology and pathology of human respiratory mechanics, but these parameters can also be used in animal testing with small animals, such as mice or rats. Depending on the experiment, a tracheostomy or endotracheal intubation should be performed: the tracheal cannula is connected to a pneumotachograph and a mechanical ventilator, which allows minute volume control, airflow, and positive end-expiratory pressure (PEEP). After stabilizing the ventilatory parameters, the mechanicals properties are measured 10-15 times in each animal, and can be used in the equation of motion as the end-inspiration occlusion method. All data were analyzed using specific software. The lungs and the chest wall are usually treated as linear dynamic systems that can be expressed by differential equations, and thereby allow the determination of system parameters that reflect the mechanical properties. The unicompartmental linear model is sufficient to detail the mechanical behavior of the respiratory system in different physiological conditions. The use of mice to create a model of airway diseases has been essential to better understand the mechanical action of lung diseases.