Multi-dimension applications of bioelectrical impedance analysis

Bioelectrical Impedance Analysis (BIA) has been shown to be an inexpensive, reliable, simple, safe, and noninvasive technique for multiple purposes, such as the prediction and detection of fluids in aviators and aircraft pilots, clinical cardiology settings, and in the estimation of body composition and body water volume in children and adults. In general, when using BIA, a low level electrical current is passed into the body or body segment of a subject using two or more electrodes. A small and constant electrical current flows between the electrodes; same or different electrodes pick up a voltage signal from the body surface of the subject. The detected voltage is expressed in terms of impedance (ohms,Ω). Development of new commercial BIA instruments, such as the body segmental BIA analyzer, multifrequency BIA analyzer, lower body BIA analyzer, upper body BIA analyzer, and laboratory designed BIA analyzers, have greatly expended the utility of this method. The present review paper summarizes some of the applications of BIA in the field of aerospace medicine, research, clinical settings in cardiology, and in the measurement of body composition and body fluid compartmentalization.