The LASCA method can be applied to the study of microcirculation of superficial microvessels. A chicken embryo of the 5th - 7th day of incubation was used as a model of the vascular system. The effect of laser occlusion of a vessel on blood microcirculation in the vascular system was studied. Using the LASCA method, we can conclude about the presence or absence of the blood flow in the vascular system. The contrast value C, calculated by the method, shows the blood redistribution in the vascular system before and after occlusion.

An estimated 10.5% of the world’s population aged 20–79 years are currently living with diabetes in 2021. An urgent task is to develop a non-invasive express-diagnostics of diabetes with high accuracy. Type 1 diabetes mellitus (T1DM) diagnostic method based on infrared laser spectroscopy of human exhaled breath is described. A quantum cascade laser emitting in a pulsed mode with a peak power of up to 150 mW in the spectral range of 5.3–12.8 μm and Herriot multipass gas cell with an optical path length of 76 m were used. We propose a method for collecting and drying an exhaled human air sample and have measured 1200 infrared exhaled breath spectra from 60 healthy volunteers (the control group) and 60 volunteers with confirmed T1DM (the target group). A 1-D convolutional neural network for the classification of healthy and T1DM volunteers with an accuracy of 99.7%, recall 99.6% and AUC score 99.9% was used. The demonstrated results require clarification on a larger dataset and series of clinical studies and, further, the method can be implemented in routine medical practice.

The analytical dependence of the signal-to-noise ratio (SNR) of the measured interferograms of an infrared (IR) Fourier spectrometer on the temperature contrast of the observation path and on the physicochemical properties of the test substance is obtained. The analytical dependences of the minimum detectable concentration of a substance on the value of the temperature contrast are obtained. It is shown experimentally that the theoretical estimates of the minimum detectable concentrations with an accuracy of the order of the mean square error correspond to the experimental values. The obtained analytical dependences make it possible for the given physicochemical properties of substances, the parameters of the IR Fourier spectrometer, and the values of the temperature contrast to estimate minimum detectable concentration of the substance.

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