Investigation of the intrabody communication through the transmission line model

With the development of technology, human body have been modelled as a transmission line and the electrical signals can be transmitted through the tissue instead of air. This case depends on electrical and physiological properties of interested tissue and titled as intrabody communication. Intrabody communication is divided into two main topics, which are capacitive coupling and galvanic coupling, according to the definition of the problem scenario. In this thesis, galvanic coupled intrabody communication has been studied by analytical and numerical methods due to the computational engineering approximations. In the studies performed with analytical methods, transmission line model of the skin layer has been investigated and accordingly, behaviour of the signal in circuit model has been discussed. Finite element method based simulations and finite difference time domain based solutions of the transmission line have been carried out for numerical analyses. Investigations have been performed at 1 MHz, 10 MHz and 21 MHz, respectively. As a result of the finite difference time domain method based investigations, it was observed that signal transmission depends on frequency and tissue parameters. Different circumstances that may be encountered by researchers are discussed in virtue of finite element method based simulations. Multi-layered cylindrical arm model has been examined as the tissue model and modelled as skin, fat, muscle, cortical bone, cancellous bone, respectively. Mentioned simulations showed that the signal behaviour observed in the tissue caused different results at various frequencies and it was related with the electrical properties of media. When the source signals at 1 MHz, 10 MHz and 21 MHz results have been compared, it was observed that the bias of the electrical properties of the tissues have been differed at the interested frequencies, and consequently, it was observed that both behaviour of the signal and the transmission line model have been varied.