Experiments and Analysis for Fractional Order Modelling of an EEG Recording Process

In this study, an original experimental setup is proposed to analyze the transfer function of an electroencephalographic(EEG) measurement chain: this setup allows to control electrodes inserted into an electrolyticmedium, and observe the electrical potentials at different points with electrodes connected to an electroencephalographicrecording system. Experimental transfer functions are obtained that enable to characterize theinfluence of the electrolyte, the electrode-electrolyte interfaces, and the medium itself. A theoretical modelcontaining so-called constant phase elements is then proposed and analysed to understand the behaviour ofthe transfer function in Bode or Nyquist representations. Experimental and theoretical systems are finallycompared.