Finite Element Modeling And Analysis Of The Galvanic Coupling Intra-body Communication Based On Digital Human Body

With the integration development of electronics, communication technology and the biomedical engineering, a new data transmission technology, the intra-body communication (IBC) gradually rose. IBC can easily carry out long-term, continuous detection of the human body physiology and real-time information feedback, which makes health care work no longer under the constraints of time and space. IBC not only has extensive prospect in the field of wireless biomedical monitoring, but also has far-reaching impact on the intelligent society.The galvanic coupling IBC is a short range wireless communication technique, which utilizes the human body as communication medium. The galvanic coupling IBC has features of low power, low radiation and anti-radiation. What’s more, the signal transmission quality is not influenced by the individual’s surroundings. As a result, The galvanic coupling IBC presented good adaptability and stability. At present, IBC technology just got preliminary application, so this thesis will analyze the channel characteristics of human body with finite element method, which providing theoretical guidance for the realization application of IBC technology. The main work in this paper can be described as follow:(1)The paper analyzed the IBC technology based on the research of electromagnetic properties。Taking the volume conductor theory and the Maxwell equations as a starting point, the control equation is derived to describe the volume conductor, boundary condition.(2) A 3D electromagnetic model basing on digital human body was presented for IBC. With the help of the volume conductor theory and the electromagnetic properties of biological tissue, the model was abstracted to layers and a multilayer cylindrical finite element model.(3) Basing on the finite element model, the thesis analyzes the influence of human conductive tissues:muscle with different electrical conductivity, wet and dry skin on the current signal transmission. And then, the influence of the electrodes with different materials, different sizes, different shapes and et al, on the signal transmission is studied.(4) The experiment platform was set up and the vivo experiments were carried out to analyze the impact of different subjects, different current, sending and receiving distance on signal attenuation. The vivo experiments could validate the accuracy of the model.In addition, the electrical signals transmission on the joints and other parts of the human body through the vivo experiments is analyzed.Regardless of finite element model simulation or the human body experiments show that galvanic coupling IBC will be affected by several common internal and external factors. Most of the current signal transmitted through the muscle layer. And the larger muscle conductivity, the more current propagates through the muscle. In 1 kHz～1MHz, the anisotropic conductivity of muscle has a great effect on signal transmission of intra-body communications. The smaller the joint angle bending has the better the signal transmission. What’s more, transceiver distance, the input signal strength, the size, shape and layout of electrodes, could also affect the voltage decay.In the paper, finite element modeling and analysis of the galvanic coupling IBC communication based on digital human body, not only enrich the theory of IBC, but also contributed to the practical application and future development of IBC.