A Goertzel Filter-Based System for Fast Simultaneous Multi-Frequency EIS

Bioimpedance measurement is a non-invasive, radiation-free, and inexpensive method for measuring the electrical properties of biological tissues. In applications where transients occur, commonly used swept sinewave replaced with broadband signals such as multisine. This makes signal generation extraction real imaginary parts impedance challenging. this brief, an alternative to traditional fast Fourier transform (FFT) or coherent demodulation presented. Based on Goertzel filter, simpler requires very few digital resources. Its robustness harmonic fold back phenomenon, enables simple ternary current pulses be excitation. The developed architecture capable simultaneous 16 frequencies accuracy 97% 96% magnitude phase respectively. Employing sequence allows use low power H-bridge driver. analog front-end algorithm were implemented in ASIC using 180-nm CMOS technology. system was tested isolated pig heart distinguishing edema from non-edema tissue by changes.