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Bioelectrical Impedance as a Technique for Estimating Postmortem Interval

NCJ Number
Journal of Forensic Sciences Dated: First Online: November 16, 2017
Date Published
November 2017
5 pages

Since estimation of postmortem interval (PMI) is a critical component of death investigations, this study tested the hypothesis that a cadaver is a resistor-capacitor (RC) circuit, the impedance (Z) of which changes in a quantifiable manner as the cadaver decomposes.


This hypothesis was tested using bioelectrical impedance analysis (BIA) equipment to apply a current with a fixed amplitude at a single frequency to four cadavers over time and measuring two components of Z, resistance (R) and reactance (Xc). Quadratic regression analysis between Z and accumulated degree days (ADD) showed a statistically significant parabolic relationship. The parabolic relationship poses an initial challenge to the use of the method, so additional research is needed to address this issue; however, the results of the reported research support the hypothesis that Z measured using BIA has a relationship to PMI. (Publisher abstract modified)

Date Published: November 1, 2017