EXPRESS DIAGNOSTICS OF DISEASES BASED ON A QUADRUPOLE MASS SPECTROMETER ANALYSIS OF EXHALED AIR

The method is proposed for express diagnostics of diseases according to the data of mass spectrometric analysis of exhaled air. An algorithm for calculating the probability of diseases has been developed and tested. The results of data processing of patients treated in two oncological clinics are presented. The calculation of the probability of disease according to the data of mass spectrometric analysis of exhaled air is based on attributing the mass spectrum of the tested patient to the mass-spectra of the corresponding control group. Each control group is formed by collecting an array of spectra from at least ten patients with the same disease. Diagnostics is performed by transforming the matrix of spectra of the control group and the spectrum of a patient being tested into the space of the principal components. The probability of a disease is determined by the Euclidean distance of the patient's coordinates from the centroid of the control group in the multidimensional space of these principal components.