Development of Bioelectrical impedance analyzer for Body composition analysis

Abstract

The human cells has different electrical conductivities. Due to difference in conductivities of cell constituents we can determine the electrical changes occurred in every constituent and characterized the human body to determine its composition such as fat free mass (FFM), fat mass (FM), total body water (TBW), Body mass index (BMI) and many other. Bioelectrical Impedance analysis (BIA) may be used for estimating body composition. It can be measured by applying a small 1mA, 50 KHz current which is injected into the body through a pair of electrodes and the induced voltage is picked up using another pair of electrodes. The impedance offered by the body to the applied current and the phase angle between the injected current and induced voltage is measured. The advantages of bioelectrical impedance method are non-invasive measurement, portability, safety, ease to use, low cost and acceptable levels of reliability and accuracy in estimation of body composition. A battery operated low cost and compact bio-impedance meter is developed which can be used for estimation of body composition parameters. It was proposed to measure body impedance and phase angle from healthy subjects using four electrode systems. The impedance values are recorded for different female and male individuals.