[On the possibility of establishing postmortem interval of human by examining the electrical conductivity of the knee joints' synovial fluid].

Objective: To study the electrical conductivity of the knee joints' synovial fluid of human's corpse for assessment of the possibility of its application as criterion of forensic medical diagnosis of postmortem interval.

Material and methods: The work was carried out on practical forensic medical material on the basis of the Bureau of Forensic Medical Expertise in the Republic of Bashkortostan. During the study, 103 corpses of both sexes, different ages who died from various causes were investigated. Synovial fluid of the knee joints from corpses in a state of putrefactive biotransformation of varying degrees of severity was used as the study subject. Measurements of the electrical conductivity value were carried out by conductometry using a calibrated cuvette and AKIP-6109 RLC-meter.

Results: It has been established during the study that low frequencies of electric current of 0.1 and 1 kHz are the most informative for achieving the work objective. Polynomials of the 2nd degree, establishing a relationship between the duration of the postmortem period and the synovial fluid's electrical conductivity value for each frequency of electric current with significance of approximation more than 0.95% at p<0.01, are developed, thar indicates the significance of the presented mathematical models.

Conclusion: It is promising to carry out further research in this direction with obtainment of formulas applicable for the mathematical calculation of the human's postmortem interval.