The stenosis inside trachea windpipe has three dominant factors; locations of stenosis, degree of stenosis and types of stenosis (Freitag et al., 2007). Each factor will give the significant impact to the airflow motion and increase the level of disease. Almost every asthmatic patient had suffered different dominant factors of stenosis. The signs and symptoms of disease are also dissimilar. Thus, the requirement of airflow analysis is very important to understand the early signs in order to predict the risk in the future.
