A Novel Field-Circuit FEM Modeling and Channel Gain Estimation for Galvanic Coupling Real IBC Measurements

Abstract

Existing research on human channel modeling of galvanic coupling intra-body communication (IBC) is primarily focused on the human body itself. Although galvanic coupling IBC is less disturbed by external influences during signal transmission, there are inevitable factors in real measurement scenarios such as the parasitic impedance of electrodes, impedance matching of the transceiver, etc. which might lead to deviations between the human model and the in vivo measurements. This paper proposes a field-circuit finite element method (FEM) model of galvanic coupling IBC in a real measurement environment to estimate the human channel gain. First an anisotropic concentric cylinder model of the electric field intra-body communication for human limbs was developed based on the galvanic method. Then the electric field model was combined with several impedance elements, which were equivalent in terms of parasitic impedance of the electrodes, input and output impedance of the transceiver, establishing a field-circuit FEM model. The results indicated that a circuit module equivalent to external factors can be added to the field-circuit model, which makes this model more complete, and the estimations based on the proposed field-circuit are in better agreement with the corresponding measurement results.

Past Results, Present Trends, and Future Challenges in Intrabody Communication

“…It was also found that attenuation is dependent on the transverse length between electrodes of the same pair, obtaining better levels of received signal by considering longer interelectrode distances. Similar computational models have later been proposed to analyze the effect of the parasitic return path [131], the influence of environmental noise [133] and real experimental conditions [134], the differences between surface-to-surface and implanted communications [130], and the use of noncontact electrodes at the transmitter [131]. A hybrid model considering both electrostatic circuit analysis and FEM model simulations has been proposed in [50] by Park et al to analyze different parameters of HBC channel such as the external coupling characteristics between the environment and the electrodes as well as the transmission performance obtained with different experimental setups comprising VNAs and miniaturized batterypowered wearable transceivers.…”

Biological Evaluation of the Effect of Galvanic Coupling Intrabody Communication on Human Skin Fibroblast Cells

“…Body Area Network (BAN) attempts to provide a suitable wireless protocol with low power consumption, high reliability, and lower emissions to collect the information from wearable sensors to evaluate the human health status anytime and anywhere. Unlike common wireless technology, intrabody communication (IBC) uses human tissue as a transmission medium [1,2], so it has the advantages of less path loss, high confidentiality, and high efficiency [3]. Because of this, it has become a potential communication technology for BAN that is standardized in IEEE 802.15.6 [4].…”

“…Recent IBC technology research has focused on physical modeling of human channels [5][6][7], in vivo measurements [3,8], and the implement of transceivers [9][10][11]. Because the human body is the transmitting medium for IBC [12], especially for the galvanic coupling type of IBC, a biological safety evaluation of the effect of the IBC electrical signal on the human body is essential.…”

A Circuit-Coupled Fem Model With Considering Parasitic Capacitances Effect for Galvanic Coupling Intrabody Communication

“…Several groups have dedicated to the research of propagation mechanism in galvanic coupling IBC. There are many different calculation methods having been proposed for IBC modeling, such as finite element method (FEM) [6,7], quasi-static field theory model [8], equivalent electrical circuit model [9][10][11][12][13], and Field-Circuit FEM [14,15]. Among them, FEM and circuit model has been most widely used in IBC.…”