METHOD OF ANALYSING HUMAN EXHALED AIR FOR CONTENT OF ETHANOL VAPOURS Russian patent published in 2025 - IPC G01N33/497 A61B5/97 G01J3/42 

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to a method for analysing human exhaled air for content of ethanol vapours. One exhales into vented gas cuvette (5). First spectrophotometer (1) is used to measure the "ON" signal corresponding to the value of light absorption in the cuvette by only ethanol vapours at a first wavelength. Signal "OFF" is measured, which corresponds to the value of total light absorption in the cuvette by ethanol and water vapours at the second wavelength. Signal "B" is measured by means of second spectrophotometer (2), which corresponds to the value of light absorption in the cuvette only by water vapours at the third wavelength. Relative humidity of air in the cuvette is measured by means of humidity sensor (12). Ambient temperature is measured by temperature sensor (11). Measurement data of signals "ON", "OFF", "B", relative humidity and temperature are transmitted to processing unit (9). Fact of beginning of exhalation and duration of exhalation is determined by change of relative air humidity in the cuvette. Degree of filling of the cuvette is determined from the value of the signal "B", relative humidity and temperature. Values of duration of exhalation and degree of filling of the cuvette are compared with minimum allowable values. Concentration of ethanol in the cuvette is determined by values of signals "ON" and "OFF" when identifying values of duration of exhalation and degree of filling of the cuvette is not less than minimum allowable. Concentration of ethanol in exhaled air is determined based on concentration of ethanol in the cuvette and degree of filling of the cuvette.

EFFECT: providing protection against false triggering and simulation of exhalation when determining presence and concentration of ethanol vapours in air exhaled by a person.

3 cl, 3 dwg, 3 tbl