Python tool for analyzing Electrochemical Impedance Spectroscopy data using CPE-based equivalent circuit model for tissue barriers

This repository provides Python scripts for processing and analyzing electrical impedance spectroscopy (EIS) data in the context of organ-on-chip applications. It includes two main tools:
(1) loading and structuring .z files into pandas DataFrames, and
(2) nonlinear least-squares fitting of impedance spectra to an equivalent electrical circuit model composed of a constant phase element (CPE, defined by capacitance and exponent α) in parallel with a resistance (RTEER), in series with an additional resistor (Rs).

The repository also contains example EIS data from an organ-on-chip system where primary lung cells were cultured for six days and their bioelectrical properties monitored in real time. The scripts generate fitted parameters, Bode plots comparing experimental and modeled data, and time-resolved outputs of TEER and capacitance. Example datasets and usage instructions are provided to facilitate reproducible EIS data analysis, with a particular emphasis on applications in organ-on-chip and bioelectronic systems.