Abstract
Around 300 million people over the world suffer from asthma [1]. Patients with this diseases have primarily difficult breathing with wheezing in respiratory sounds, cough and feeling of constricted chest.
Therefore their physical activity is strongly limited [2]. There are several methods for asthma diagnosis currently, e.g. spirometry, measuring of peaks of expiratory velocity or measuring of bronchial reactivity.
Although these methods are sufficiently reliable in most cases, they have also some imperfections, which are obvious especially by diagnosing of badly collaborating patients, e.g. small children aged up to three years. These infants can't provide operations required for diagnosis, so results performed diagnosis are not reliable.
Based on this reason, there is an idea to develop method of asthma diagnosis and other pulmonary diseases, that would not need collaboration of patient [1]. One of usable principles, on that the such a method could work and which this paper deals with, is comparison of air flow in airways of healthy and diseased human.
The difference of the air flow is caused by bronchial obstruction and constriction of airways of patient. There are other sounds and wheezing in the respiratory sounds detectable during breathing as a typical manifestation of the disease [3].
These phenomena can be detected e.g. by harmonic analysis.