Do the Bio-impedance Models Exhibit Pinched Hysteresis?

2020Abdelrahman D.K.Fouda M.E.Mohammed R.Radwan A.G.Said L.A.

Recently, pinched hysteresis has been found in the electrical modelling of regular plant tissues. Usually, the biological tissues are characterized in the frequency domain using bio-impedance analyzers without investigating the time domain, which would show the pinched hysteresis. In this paper, the current-voltage analysis of some of the widely known electrical bio-impedance models is studied. The investigated models are the single dispersion Cole-impedance model, the double dispersion Cole-impedance model and the fractional-order simplified Hayden model to prove that these models can not exhibit pinched hysteresis. It is proved mathematically in this paper that there are no pinch-off points that would exist in these models. These results are verified with numerical simulations of three different plants: tomato, carrot and banana, concluding that the bioimpedance modelling needs a nonlinear element to model the pinched hysteresis in the current-voltage behaviour of these tissues. © 2020 IEEE.

Generalized ?+?-order Filter Based on Single CCII

2020Ghoneim M.S.Khalil N.A.Madian A.H.Radwan A.G.Said L.A.

Different generalized filters topologies are proposed in the fractional-order domain. Three voltage-mode topologies and one current-mode topology are used to realize several types of fractional-order filters by applying different admittances combinations. The proposed topologies are designed using a single second-generation current conveyor (CCII-) and two fractional-order capacitors, which add more degrees of freedom for the design. The generalized Fractional Transfer Function (FTF) for each proposed topology is investigated where the fractional-order low-pass, band-pass, high-pass, and notch filters with ?+?)-order are realized. The Numerical results are provided where the stability analysis is presented for different cases. Also, the PSPICE simulations are presented to prove the theoretical findings of selected cases. © 2020 IEEE.

On Series Connections of Fractional-Order Elements and Memristive Elements

2020Fouda M.E.Khalil N.A.Radwan A.G.Said L.A.Soliman A.M.

This paper proposes a current-controlled fractional-order memristor emulator based on one active building block. The emulator consists of a multiplication mode current conveyor (MMCC) block with three passive elements. Additionally, the series connection of fractional-order inductor (FOI) and fractional-order capacitor (FOC) with memristive elements in the i-v plane is demonstrated numerically for different cases. Changing the order of the FOC or FOI and its effect on the pinched hysteresis loop area are investigated, which improve the controllability of the double loop area, the location of the pinched point, and the operating frequency range. Numerical, PSPICE simulation results, and experimental verification are investigated for different cases to approve the theoretical findings. Moreover, a sensitivity analysis using Monte Carlo simulations for the tolerance of the discrete components of the memristor emulator is investigated. © 2020 IEEE.