Influence of ethyl alcohol on accuracy of time since death estimation by the method of avtofluorescent laser polyarimetry of polycristalline films of cerebrospinal fluid

Due to the high prevalence of death on the base of alcoholic intoxication of varying degrees, it is expedient to analyze the possibility of the influence of alcohol on the change in the structure of the polycrystalline films of the cerebrospinal fluid, and accordingly on the accuracy of the diagnosis of the time since death by the method of autofluorescent laser polarimetry.The purpose of the work. To study the possible influence of alcohol and to develop objective forensic criteria for diagnosing its effects on the basis of analysis of changes in the polycrystalline structure of cerebrospinal fluid (CSF) films. Materials and methods. Object of research: native films of CSF, selected in 80 corpses, in the quantity of 155 samples - 1 group; CSF from 30 healthy volunteers (group 0) - 30 samples; CSF films obtained in the deceased with the presence of ethyl alcohol in the blood, 30 samples - group 2. The methods of gas-liquid chromatography, laser-induced fluorescence and statistical processing of the results were used. Results. The efficiency of using the methods of laser autofluorescence of polycrystalline films of the cerebrospinal fluid for the diagnosis of the time since death was proved. A statistically significant difference between cases of death from cardiovascular pathology with the presence and absence of ethyl alcohol in the organism was established by determining the magnitude of the statistical moment of the 4th order, which characterizes distribution of azimuth polarization values of microscopic images of laser-induced fluorescence. On this basis, an excellent balanced accuracy of the differentiation of the presence of ethyl alcohol in the human body (Ac (M4) = 94%) was achieved. Conclusion. Ethyl alcohol affects the structure of the polycrystalline films of the cerebrospinal fluid, which must be taken into account when estimating the time since death by autofluorescence laser polarimetric methods.