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Measuring Desiccation: A System Using Bioelectrical Impedance Analysis

NCJ Number
Date Published
September 2018
67 pages
This study examined the estimation of postmortem interval in an arid environment, where bodies regularly desiccate, which is the removal of water from the tissue.

The study used a qualitative method that scores gross change by assigning a standardized total body desiccation score (TBDS) and a quantitative method that used bioelectrical impedance analysis (BIA). The TBDS scale describes the changes observed between desiccation and skeletonization. BIA shows promise as a technique for estimating the PMI; however, additional research is needed to understand the sources and mechanisms of variation in the statistical models and the techniques. BIA uses an alternating current at a fixed frequency to measure electrical resistance and reactance within a biological tissue circuit. Resistance measurements are based on the composition of electrolyte gradients within the extracellular fluid; and reactance measures the capacitance of the phospholipid bilayer of cell membranes. Relationship between bioelectrical properties and the PMI were demonstrated in rats (Querido, 1993). The incorporation of multiple PMI estimation methods into a single model shows promise for reducing error in PMI estimates. The overall result of the research is significant improvement in two techniques for estimating PMI in desiccated remains, with BIA being used for the first time on human remains. Also, the research has provided a better understanding of the mechanisms of the skeletonization of desiccated remains. 5 figures, 1 table, and 24 references

Date Published: September 1, 2018