Bioelectrical Impedance as a Technique for Estimating Postmortem Interval

• NCJ Number: 251491
• Journal: Journal of Forensic Sciences Dated: First Online: November 16, 2017
• Author(s): Eriek S. Hansen; Christiane Baigent; Sophia I. Reck; Melissa Connor
• Date Published: November 2017
• Length: 5 pages
• Grant Number(s): 2015-DN-BX-K015
• Sponsoring Agency: National Institute of Justice (NIJ)
• Publication Format: Article
• Publication Type: Research (Applied/Empirical); Report (Study/Research); Report (Grant Sponsored); Program/Project Description
• Language: English
• Country: United States of America
• Note: Supported by Award No. 2015-DN-BX-K015, awarded by the National Institute of Justice, Office of Justice Programs, U.S. Department of Justice. The opinions, findings, and conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect those of the Department of Justice. Presented in part at the 69th Annual Scientific Meeting of the American Academy of Forensic Sciences, February 13-18, 2017, in New Orleans, LA.

Annotation

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.

Abstract

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)