High-speed Intra-body Communication System Through Fat Tissue Using Wearable Antennas for Health Monitoring.

Abstract

In this article, the design of a non-invasive wearable antenna-based fat intra-body communication (Fat-IBC) system is presented for biomedical applications. The Fat-IBC system is used for uninterrupted communication between various wearable, implanted, and semi-implanted devices, facilitating the exchange of data and information within body area networks (BAN). Herein, to eliminate the design complexity, a simple planar-loop antenna is considered to establish the Fat-IBC link. For the numerical analysis, a three-layer human body tissue model (skin, fat, and muscle) is considered to optimize the antenna. A polydimethylsiloxane (PDMS) coating layer is deposited around the wearable antenna to eliminate direct contact with the human body. In addition, the antenna has also been shielded by a ferrite substrate and copper tape to reduce the loss of energy in undesired directions and stop the surface wave propagation over the skin tissue. The Fat-IBC system is constructed by using two identical wearable antennas that act as transmitting (Tx) and receiving (Rx) elements. These antennas have been placed on the three-layer human body tissue models at different distances to demonstrate the data transmission. The concept of the proposed wearable antenna-based Fat-IBC system has been established by numerical simulations and validated by experimental studies using phantoms. The proposed data transmission link was characterized using scattering parameters and the IEEE 802.11n wireless communication standard with combinations of on-skin wearable antennas. To achieve high in-body data rate using on-body antennas through the fat layer, a wireless LAN at the 2.4 GHz band was tested using low-cost Raspberry Pi single-board computers. The phantoms are utilized for measurement purposes to emulate the human body. For the proposed Fat-IBC system, a maximum link speed of 93 Mb/s is achieved using the 40 MHz bandwidth provided by the IEEE 802.11n standard at the frequency of 2.4 GHz. The obtained results demonstrate that the proposed Fat-IBC system, utilizing low-cost off-the-shelf hardware and established IEEE 802.11 wireless communication, can achieve high-speed data communication through three-layer phantom tissue.