Intra‐body microwave communication through adipose tissue

Abstract

The human body can act as a medium for the transmission of electromagnetic waves in the wireless body sensor networks context. However, there are transmission losses in biological tissues due to the presence of water and salts. This Letter focuses on lateral intra-body microwave communication through different biological tissue layers and demonstrates the effect of the tissue thicknesses by comparing signal coupling in the channel. For this work, the authors utilise the R-band frequencies since it overlaps the industrial, scientific and medical radio (ISM) band. The channel model in human tissues is proposed based on electromagnetic simulations, validated using equivalent phantom and ex-vivo measurements. The phantom and ex-vivo measurements are compared with simulation modelling. The results show that electromagnetic communication is feasible in the adipose tissue layer with a low attenuation of ∼2 dB per 20 mm for phantom measurements and 4 dB per 20 mm for ex-vivo measurements at 2 GHz. Since the dielectric losses of human adipose tissues are almost half of ex-vivo tissue, an attenuation of around 3 dB per 20 mm is expected. The results show that human adipose tissue can be used as an intra-body communication channel.

Data Packet Transmission Through Fat Tissue for Wireless IntraBody Networks

“…For this work, however, we propose the communication through the fat tissue, which offers lower losses for microwave propagation compared to other tissues. We have previously demonstrated the feasibility of using fat tissue as a low loss microwave transmission channel for intra-body communication [32][33]. But, for a successful communication scenario, real data has to be transferred through a given channel.…”

Characterization of the Fat Channel for Intra-Body Communication at R-Band Frequencies

“…The microwave intra-body communication through the fat tissue, coined as "fat channel" [19] is a new technique that uses the fat tissue as a communication channel. Previous studies have proven the feasibility of using the fat tissue as a transmission medium for microwave signals at 2.0 GHz [19,20].…”

“…Previous studies have proven the feasibility of using the fat tissue as a transmission medium for microwave signals at 2.0 GHz [19,20]. Still, there is a need to improve the characterization of the microwave communication through the fat tissue, which has not been taken into account in previous research.…”

“…The thickness of the skin, fat, and muscle are 2 mm, 25.36 mm, and 30 mm, respectively. These dimensions are chosen based on the average human body tissue thickness and in accordance with previous studies [19,20,23]. The 2 mm thick skin is chosen by taking the average thickness of human adult [24].…”

“…The average thickness of human fat tissue is found to be 25 mm [25]. The 30 mm muscle thickness is chosen for the current study based on our previous numerical investigations [19].…”