Bioimpedance Analysis: Basic Concepts

Abstract

Bioimpedance analyzers uses these differences in the electrical properties of the human body to analyze the cellular and water components. Human body acts as a semiconductor, with the various body compartments offering resistance (R) and reactance (X) to the passage of alternating current. The X and R thus measured can be used in validated regression equations or mathematical models to provide information on body water, fat, and fat-free mass. Depending on the number of frequencies used, the available equipments include single frequency, multifrequency and bioimpedance spectroscopy. The bioimpedance vector analysis is an alternative tool that uses the raw values of X and R, corrected to height, to categorise the hydration status as well as muscle mass.