A Preliminary Investigation of Human Body Composition Using Galvanically Coupled Signals

Intrabody communication (IBC) archetype is a novel healthcare network technology that enables non-RF based wireless data communication through the human body. The lowpower IBC signals are conned to the body, making it suitable for transmitting health data of monitored vital human body signs such as heart-beat and blood pressure. Research in IBC communication usually focuses on channel characteristics for transceiver improvements in reliability, data rates and energy savings. In this paper we introduce a novel application of IBC galvanic coupling circuit for investigating human body composition. We compare empirical measurements using a vector network analyzer with circuit model simulations. The results show dierent attenuations observed for dierent proportions of the body tissue such as fat, muscle and bones. We found that a dierence in body mass index (BMI) by 1 kg/m2 between the subjects results in approximately 1 dB increase in attenuation. Also, the signal attenuation increases with the BMI of the subjects but are also aected by their respective hydration states. We also found that frequencies above 5 MHz would not be suitable for estimating human body composition in a galvanic coupling IBC circuit. However, a wider experiment is required to give the range of data values that will correspond to attenuation for dierent body mass index by sex and age.