[Assessment of impedancemetric characteristics of cadet tissues depending on the number of accumulated degree-days].

چکیده اصلی

OBJECTIVE: Analysis and comparison of impedance parameters of cadaveric tissues and their dynamics depending on the number of accumulated degree-days. Materials and methods: the experiment was carried out on model objects - pig cadavers (skin flap, cartilage, tendon) under two conditions: standardized (+4 °C, humidity around 40%, condition I) and natural biocenosis (average temperature around +18.5 °C, condition II). The impedance modulus and phase shift angle θ were measured at five frequencies f (100 Hz, 120 Hz, 1 kHz, 10 kHz, 100 kHz) at different times of the postmortem interval; a Keysight U1733 device was used. Various coefficients were calculated for dispersion analysis, and time referencing was carried out by calculating the number of accumulated degree-days. Measurements were also carried out on embalmed anatomical preparations. RESULTS: The study demonstrates that calculating accumulated degree-days allows for the reconciliation and quantitative comparison of changes in the impedance characteristics of cadaveric tissues obtained under various environmental conditions. An important result is that similar values of accumulated degree-days (~300 degree-days) correspond to similar qualitative changes in tissues under standardized and natural conditions, and the θ-lgf trend equations for similar values of accumulated degree-days coincide or are close in coefficients. CONCLUSION: This confirms the predictive value of calculating the number of accumulated degree-days when interpreting impedance measurements to clarify the duration of the postmortem period and the possibility of extrapolating results obtained under certain temperature conditions to other environmental conditions. However, further research is needed to explore the mechanisms of postmortem biophysics, expand the sample size (including human cadavers), examine the influence of entomological and other factors, and validate the methodology for practical use in forensic practice.

متن کامل اصلی