Determination of resistance at zero and infinite frequencies in bioimpedance spectroscopy for assessment of body composition in babies

This study investigated an alternative data modelling procedure obviating issues associated with BIS measurements in babies and infants. Approach. BIS data are conventionally analysed according to the Cole model describing the impedance response of body tissues to an applied AC current. This approach is susceptible to errors due to capacitive leakage errors of measurement at high frequency. The alternative is to model BIS data based on the resistance –frequency spectrum rather than the reactance-resistance Cole model thereby avoiding capacitive error impacts upon reactance measurements. Main results. The resistance–frequency approach allowed analysis of 100% of data files obtained from BIS measurements in 72 babies compared to 87% successful analyses with the Cole model. Resistance–frequency modelling error (percentage standard error of the estimate) was half that of the Cole method. Estimated resistances at zero and infinite frequency were used to predict body composition. Resistance-based prediction of fat-free mass (FFM) exhibited a 30% improvement in the two-standard deviation limits of agreement with reference FFM measured by air displacement plethysmography when compared to Cole model-based predictions. Significance. This study has demonstrated improvement in the analysis of BIS data based on the resistance frequency resp onse rather than conventional Cole modelling. This approach is recommended for use where BIS data are compromised by high frequency capacitive l...

Source: Physiological Measurement - May 6, 2024 Category: Physiology Authors: Natalia Pinheiro-Castro, Tamiris Ramos-Silva, Patricia Helen de Carvalho Rond ó and Leigh C Ward Source Type: research