Sarkisova Y. Diagnostic of prescription of death coming by means of the methods of multidimensional polarization and autofluorescence microscopy of the human vitreous body

Despite the importance of accurate determination of the time since death (TSD) during the examination of a corpse, in particular during the investigation of criminal cases, the high variability of the available methods for estimating the postmortem interval prompts the search for new approaches to solving this problem. Therefore, the dissertation is devoted to the development of a set of new objective forensic medical criteria for expanding the functional capabilities of the accurate establishment of the TSD over a long time interval by using polarization and autofluorescence microscopy of the human vitreous body (VB). Added scientific data on the possibilities of the method of determining the amount of K+ and Na+ of the VB for the forensic establishment of TSD. According to the amount of K+, the duration of the postmortem interval can be determined with an accuracy of up to 4-6 hours at an interval of up to 18 hours and with an accuracy of 8-12 hours at later times. By statistical analysis of the coordinate distributions of the MMI value of the partially depolarizing layers of ST, diagnostic criteria were revealed (SM3 from 0.43 to 1.27; SM4 from 0.34 to 1.38) and achieved a stable level of accuracy (45 min) determining the TSD within 24 hours. Additional large-scale selective wavelet analysis of phase polarization microscopic images and Mueller matrix maps of VB layers for the first time provided an improvement in the accuracy (40 min) of determining the TSD within 36 hours. For the first time by the method of differential Mueller-matrix mapping of the polycrystalline component of the VB layers by estimating the temporal dynamics of the change in the magnitude of the statistical moments of the 3-4th orders amplitudes of wavelet coefficients Сa=15,b (SM3 from 0.24 to 1.43; SM4 from 0.33 to 1.79) TSD was determined with a sensitivity range of 36 h and an accuracy of 30 min. Polarization tomographic reproduction of the parameters of birefringence of the polycrystalline component of the VB layers for the first time provided the determination of the TSD with an accuracy of 20 min – for 24 hours. Scale-selective analysis of the distributions of the amplitudes of the wavelet coefficients of birefringence maps of the polycrystalline component of VB layers improved the accuracy of the tomographic method up to 15 min and extended the time interval to 36 hours. For the first time, a method of spectral-selective fluorescence microscopy of intensity distributions of laser-induced autofluorescence of amorphous and protein component of the VB layers was developed for the accurate determination of TSD over long time intervals. A set of forensic medical criteria for determining TSD by monitoring the temporal changes in the set of statistical moments of the 1-4th orders, which characterize the distributions of the intensity of autofluorescence layers of the VB in different spectral regions (“blue” – 415 μm, “green-yellow” – 550 μm). Based on this, for the first time, the accuracy of determining the TSD of 15 min was achieved at a time interval of 36 hours after death. The practical significance of the obtained results, and their implementation in practice. The obtained results of the conducted experimental studies broadened the understanding of the mechanism of thanatogenesis and approaches to the determination of the TSD, as well as added to the volume of knowledge regarding the peculiarities of the biochemical composition and polycrystalline structure of the human VB and their postmortem changes. Scientific developments are implemented in the practical activities of the Chernivtsi, Ivano-Frankivsk, Kirovohrad, and Zhytomyr regional bureaus of forensic medical examination, as well as in the educational process of the Departments of Forensic Medicine and Law of National Pirogov Memorial Medical University; of Forensic Medicine and Medical Law of the Ivano-Frankivsk National Medical University; of forensic medicine and medical law of the Bogomolets National Medical University; of pathological anatomy with a sectional course and forensic medicine of the I. Horbachevsky Ternopil National Medical University; of Forensic Medicine and Medical Law of the Bukovinian State Medical University, which is confirmed by the relevant acts of implementation.