POST-MORTEM INTERVAL ESTIMATION USING POLYCRYSTALLINE CEREBROSPINAL FLUID FILMS TWO-DIMENSIONAL CARTOGRAPHY OF MUTUAL LASER POLARIZATION DISTRIBUTION LEVELS

Marta Garazdiuk,Oleh Wanchuliak,Oleksandr Garazdiuk,Natalia Pavlyukovich,Oleksandr Pavlyukovich

doi:10.12955/cbup.v6.1267

Abstract

Post-mortem interval estimation is one of the most important issues in forensic practice. Optical diagnostic methods of biological tissue structure assessment are perspective in this area.The objects of investigation are polycrystalline films of cerebrospinal fluid, taken from 64 corpses with accurately known times of death and 15 healthy volunteers.The method of two-dimensional stokes-polarimetric mapping of distributions of a complex degree of mutual polarization with spatial-frequency filtration of microscopic images of cerebrospinal fluid films in the time monitoring of post-mortem changes in optical manifestations of polycrystalline networks has been tested in order to estimate the post-mortem interval. The most sensitive post-mortem changes in the optical manifestations of polycrystalline cerebrospinal fluid networks are revealed - statistical moments of the third and fourth orders that characterize the asymmetry and the excess (severity of the peak) of the distributions of values of the complex degree of mutual polarization of large-scale components of cerebrospinal fluid polycrystalline films microscopic images.An interval of 48 hours with the accuracy of the post-mortem interval estimation in ± 30 minutes were established by the method of two-dimensional mapping of distributions of the values of a complex degree of mutual polarization of large-scale component of cerebrospinal fluid films microscopic images.

Highlights

One of the most important issues of forensic practice is the estimation of the postmortem interval (PMI) - this issue covers both medical and legal aspects, since the precise definition of this indicator allows more accurate crime investigation (Salam et al, 2012; Arroyo et al, 2005)
Physical methods of human biological tissues (BT) research using laser technologies, which include a complex of photometric, polarization and correlation techniques, demonstrated high efficiency of PMI estimation and bodily injuries lifetime
The study of the interrelation between polarization parameters, such as azimuthal distributions and polarization ellipticity, Stokes vector parameters, elements of the Müller matrix, indicators of a complex degree of mutual polarization of images of sections of BT, and the use of statistical analysis, allows us to investigate and interpret the changes in biological objects of research with high accuracy, which was demonstrated in the example of the research of tissues of the parenchymal organs, the skin and the human brain for the diagnosis of PMI (Ushenko et al, 2013; Bachinsky et al, 2000; Ushenko et al, 2011)

Summary

Introduction

One of the most important issues of forensic practice is the estimation of the postmortem interval (PMI) - this issue covers both medical and legal aspects, since the precise definition of this indicator allows more accurate crime investigation (Salam et al, 2012; Arroyo et al, 2005). Physical methods of human biological tissues (BT) research using laser technologies, which include a complex of photometric, polarization and correlation techniques, demonstrated high efficiency of PMI estimation and bodily injuries lifetime. The study of the interrelation between polarization parameters, such as azimuthal distributions and polarization ellipticity, Stokes vector parameters, elements of the Müller matrix, indicators of a complex degree of mutual polarization of images of sections of BT, and the use of statistical analysis, allows us to investigate and interpret the changes in biological objects of research with high accuracy, which was demonstrated in the example of the research of tissues of the parenchymal organs, the skin and the human brain for the diagnosis of PMI (Ushenko et al, 2013; Bachinsky et al, 2000; Ushenko et al, 2011). For biological fluids (BF) and environments of the body, a model of supramolecular entities is a liquid crystal analogue, where, as a liquid crystal, which has the form of elongated molecules oriented in one, two or three dimensions, an organized liquid acts with an ordered character of units held by the forces of attraction (Ushenko et al, 2011)

Objectives

Methods

Conclusion