Physical Multi-Layer Phantoms for Intra-Body Communications

This paper presents approaches to creating tissue mimicking materials that can be used as phantoms for evaluating the performance of Body Area Networks (BAN). The main goal of the paper is to describe a methodology to create a repeatable experimental BAN platform that can be customized depending on the BAN scenario under test. Comparisons between different material compositions and percentages are shown, along with the resulting electrical properties of each mixture over the frequency range of interest for intra-body communications; 100 KHz to 100 MHz. Test results on a composite multi-layer sample are presented confirming the efficacy of the proposed methodology. To date, this is the first paper that provides guidance on how to decide on concentration levels of ingredients, depending on the exact frequency range of operation, and the desired matched electrical characteristics (conductivity vs. permittivity), to create multi-layer phantoms for intra-body communication applications

Body Mass Index (BMI) Effect on Galvanic Coupling Intra-Body Communication

Intra-body communication (IBC) is a wireless communication system where human body is used as a signal transmission medium. Main advantage of IBC compared to other wireless communication is capable of low power consumption. There are two coupling methods in IBC, which are capacitive and galvanic coupling. The characteristic of human body play an important role in IBC because the transmitted signal is propagates through the body tissue. Therefore, this paper investigates the effect of different dielectric properties of body tissues to the quality of IBC signal transmission by focusing at body fat. Galvanic coupling method was used. 12 subjects were volunteered in this study and the value of subject’s body fat was differentiates by body mass index (BMI). The frequency was focused on 21 MHz, 50 MHz and 80 MHz. The signal quality at 21 MHz and 80 MHz shows the degradation as the increasing of body fat. The signal attenuation is increasing as body fat increased because in human body, the bone and fat has higher resistance than nerves and muscle. However, at frequency 50 MHz, the increasing of human BMI does not increase the attenuation where the attenuations are at peak value

Measurement and Modeling of Wireless Off-Body Propagation Characteristics under Hospital Environment at 6-8.5 GHz

© 2013 IEEE. A measurement-based novel statistical path-loss model with a height-dependent factor and a body obstruction (BO) attenuation factor for off-body channel under a hospital environment at 6-8.5 GHz is proposed. The height-dependent factor is introduced to emulate different access point (AP) arrangement scenarios, and the BO factor is employed to describe the effect caused by different body-worn positions. The height-dependent path-loss exponent is validated to fluctuate from 2 to 4 with AP height increasing by employing both computer simulation and classical two-ray model theory. As further validated, the proposed model can provide more flexibility and higher accuracy compared with its existing counterparts. The presented channel model is expected to provide wireless link budget estimation and to further develop the physical layer algorithms for body-centric communication systems under hospital environments