Body Mass Composition Measurements Using a Portable Device

This paper is concerned with the measurement of bio-impedance of the human body to estimate its body mass composition. This approach to body composition (bio-impedance and bio-impedance analysis) is currently one of the most widely used methods that can provide quantitative information about crucial body composition elements such as total body water (TBW), fat mass (FM), and fat-free mass (FFM), as well as several other parameters. We have developed and tested a portable device that meets the requirements for safety, cost-effectiveness, and portability to measure body composition using multi-frequency excitation. A novel algorithm based on a modified KramerKronig transform was used to estimate the phase angle of bioimpedance without actually measuring it. This greatly simplifies the hardware of the instrument without compromising its accuracy. Comparisons were made with measurements made with an industry standard device at 50 kHz.