PHY Design and Implementation of a Galvanic Coupling Testbed for Intra-Body Communication Links

Abstract

Intra-body communication (IBC) is a novel key research area that will foster personalized medicine by allowing in situ and real time monitoring in daily life. In this work, the energy efficient galvanic coupling (GC) technology is used to send data through intra-body links. A novel sound card-based GC testbed is designed and implemented, whose main features are: (i) low equipment requirements since it only employs two ordinary PCs with sound card support and Matlab software, (ii) high flexibility since all the parameters setting may be easily modified through the PC control panel and Matlab programs, (iii) real time physiological data transmissions, and (iv) almost error free communication by developing specific physical (PHY) layer techniques, which are implemented and tested with a real chicken tissue in the experimental evaluation. A signal to noise ratio (SNR) calculation is also proposed with the twofold purpose to be used for frequency offset compensation and as metric to evaluate the proposed architecture. The developed GC testbed may be easily replicated by the interested research community to carry out simulation-based experiments, thus fostering new research in this field. Moreover, the Matlab source code of the proposed GC transceiver is freely available online on Code Ocean.

PHY-DTR: An Efficient PHY based Digital Transceiver for Body Coupled Communication using IEEE 802.3 on FPGA Platform

“…The Stability of AFE in the frequency range is up to 1MHz, and AFE reduces the interference margin to a great extent. Vizziello et al [30] present PHY implementation for IBC links using a galvanic coupling. The Galvanic coupling method analyses the selection of modulation schemes, frequency parameters, and recovery of baseband signals.…”

Electromyography Data Transmission via Galvanic Coupling Intra-body Communication Link

“…Fig. 1 illustrates the GC transceiver where a pair of electrodes representing the transmitter are placed on the skin with a typical distance of 5 cm to inject weak electrical currents as data signals [13]. While the primary current flows between the two transmitter electrodes, very low secondary currents carry the information to a distant pair of receiver electrodes through multiple tissues conduction.…”

“…We here employ the GC platform that we have developed in [12], [13], whose main features are its easy repeatability and physical layer (PHY) methods able to obtain almost error free performance. The GC testbed [12], [13] leverages on PC sound card and Matlab software since GC frequency range (1 KHz -100 MHz) [6] includes the signals' frequencies supported by the sound cards. A Matlab session must be open in each of the two PC to run the transmitter and receiver software respectively.…”

“…PHY methods are implemented in the transmitter/receiver (tx/rx) Matlab programs, which include phase, frequency and time recovery. The source code of the GC transceiver [13] is available online for the interested community [14].…”

“…In this paper we specifically transfer electromyography (EMG) data in both ex-vivo and in-vivo tissue employing the GC testbed [13].…”