Finite Element Simulation And Experiment Of Intra-body Communication With Different Transmission Paths

Intra-body communication(IBC)uses the human body as a transmission medium for electrical signals,which is a novel method to achieve the on-body to on-body(OB-OB)communication for the wearable devices and the two-way communication of in-body to on-body(IB-OB)and on-body to in-body(OB-IB)for implantable devices in Body Area Network(BAN).Nowadays,most of the human body channel models used in the study of IBC transmission path are local body models or the whole body model that is composed of abstract geometry.Thus,they have some influences on the accuracy of the human body.Furthermore,the existing researches on the two-way communication of IB-OB and OB-IB for implantable devices are mainly focused on IB-OB transmission path,and few researches are related to OB-IB transmission path.In this work,a finite element model(FEM)of the whole human body model based on visible human data was developed.And the channel characteristics of OB-OB,IB-OB and OB-IB IBC with different signal transmission paths were discussed by finite element simulation,in vivo and phantom experiment.Thus,the detailed researches of this work are as follows:Firstly,based on the visible human data,a geometric model of the whole human body was established.And combined with the electrical characteristic parameters of human body tissue and IBC control equation of channel modeling theory knowledge,the finite element simulation platform of OB-OB,IB-OB and OB-IB were built as the basis for the subsequent finite element simulation.Secondly,the channel characteristics of OB-OB IBC with different communication paths were studied.The finite element simulation experiment and in vivo experiment of the short channel transmission path of different parts of the human body and long channel with different transmission paths were carried out by using the digital whole body FEM and in vivo experiments.The results showed that,from 10 kHz to 1MHz,the channel characteristics of short channel with different transmission paths were similar to characteristics of low pass filter,while the channel characteristics of long channel was similar to "?" channel.Besides,the error between FEM of the whole human body and in vivo experiment was lower than 6 dB.Finally,the attenuation characteristics of IB-OB and OB-IB IBC with different transmission paths were studied.The model of the whole human body's legs was used as the research object,and the electrodes were implanted in the junction of fat and muscle layers of the calf and thigh.Then the finite element method was used to analyze the channel characteristics of IB-OB and OB-IB IBC with different transmission paths in the finite element model of legs.Besides,based on the implanted leg phantom,the phantom experiments of IB-OB and OB-IB IBC with different transmission paths were carried out.The results showed that the curves of signal gain and channel length of different transmission paths in IB-OB and OB-IB IBC was similarity.And the consistency coefficient of IB-OB and OB-IB was over 98%,which indicates that the body channel was bidirectional.The results provide theoretical reference for IBC transceiver design in duplex mode.In conclusion,this work studied IBC with different signal transmission paths from OB-OB,OB-IB and IB-OB to explore the channel characteristics of IBC with different transmission paths.The results of this work provided a whole-body channel model for the research of IBC,a theoretical basis for the design of IBC transceiver,and the research of implantable communication channel.