Edited by: Luca Giovanni Bottoni
Gone are the times in which we trusted the home balance, an instrument that is based on measuring the global weight of whatever we lean on, not taking into account different aspects of the human body as its composition "fundamental factor for a evaluation of a physical state ". To date, all in vivo methods for determining body composition are indirect. This means that all these methods provide estimates, however accurate, not direct measures.
BIA (Bioimpedentiometry) is a bioelectric examination for quantitative and qualitative analysis of body composition. The measurement of the Resistance and of the Reactance that meets a weak current that crosses the human body allows us to establish, thanks to some appropriate formulas, an immediate interpretative scheme about the state of hydration and nutrition of the subject. In the absence of hydro-electric alterations, the correlations between the various body compartments are constant and interdependent, so as to allow quantitative assessment with high precision. The bioelectric values of Resistance and Reactance measured are divided by the height of the subject to obtain conductivity in order to transform the electrical properties of the tissues into a clinical datum.
Not everyone knows that one of the first applications of bioelectrical impedance analysis was for military purposes: in the second half of the 1970s, Prof. Jan Nyboer together with two students of that time, Rudy J. Lietdke and Tony Talluri, analyzed the changes in hydration for high altitude pilots. Following the experience gained, the first commercial impedance analyzer was produced: the BIA 101 Akern RJL System sensor.
