METHOD OF BRONCHIAL OBSTRUCTION DIAGNOSTICS Russian patent published in 2009 - IPC A61B5/08 A61B5/107 A61B10/00 

FIELD: medicine.

SUBSTANCE: invention relates to medicine, in particular to pulmonology, and is intended for non-invasive diagnostics of bronchial obstruction. Measuring of chest circumference (chest circ.) is carried out in state of quiet breathing. The following parametres of forced exhale (FE) sounds are measured - general duration of FE sound (T_gen), time of amplitude growth (T_growth), frequency of maximal FE sound energy (F_max), coefficient (Q_exh) - ratio of total energy of low (LF) and middle (MF) to energy of high frequencies (HF), part of relative HF, MF and LF energy in per cent. In addition, determined are index of body weight (BWI), peak exhale velocity (PEV), "smoker" index (SI) being calculated by formula SI = number of smoked cigarettes per day * record of smoking / 20; presence of professional harmfulness, absence of professional harmfulness (Prof.harm.) in medical history being estimated as 0 points, presence of professional harmfulness in medical history being estimated as 1 point. Degree of bronchial obstruction is determined by formula: Obstruction coefficient = -34.2749 + 0.8512*BWI + 0.1894*Chest circ. - 0.0048*SI - 2.7608* Prof.harm. + 0.6681 * PEV -0.3080 * T_gen - 13.9132 * T_growth + 0.0056 * F_max - 6.8414 * Q_exh - 0.0691 * LF + 0.685 * MF + 0.0117 * HF. If obstruction coefficient is within the range from 100 to 86.456, there is no bronchial obstruction, if it is within the range from 86.455 to 80.887 mild bronchial obstruction is diagnosed, if it is within the range from 80.886 to 43.684 moderate bronchial obstruction is diagnosed, if it is within the range from 43.683 to 0 - severe bronchial obstruction is diagnosed.

EFFECT: method allows to increase efficiency of bronchial obstruction diagnostics due to detection of more reliable objectively estimated characteristics of FE sounds depending on build-up and physical development of examined people, peakflowmetry data, as well as risk factors influence.

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