Using of chirp excitation for bioimpedance estimation: Theoretical aspects and modeling

In this paper, theoretical considerations and simulation results of a method for quick estimation of the bioimpedance (BI)vector over a wide range of excitation frequencies are discussed. This method uses a chirp signal with linearly modulated frequency for excitation. The response signal is processed using cross-correlation techniques together with following fast Fourier transform (FFT). As the result, the complex spectrum of the response signal is attained in the range of frequency, determined by the spread of chirp pulse. This spectrum characterizes the frequency response of the impedance under study.