Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Jun 12;25(12):3688.
doi: 10.3390/s25123688.

Design and Validation of Low-Cost, Portable Impedance Analyzer System for Biopotential Electrode Evaluation and Skin/Electrode Impedance Measurement

Jaydeep Panchal  1 , Moon Inder Singh  1 , Mandeep Singh  1 , Karmjit Singh Sandha  1
Affiliations

Design and Validation of Low-Cost, Portable Impedance Analyzer System for Biopotential Electrode Evaluation and Skin/Electrode Impedance Measurement

Jaydeep Panchal et al. Sensors (Basel). .

Abstract

This paper presents a novel, low-cost, portable impedance analyzer system designed for biopotential electrode evaluation and skin/electrode impedance measurement, critical for enhancing bioelectrical signal quality in healthcare applications. In contrast with conventional systems that depend on external PCs or host devices for data acquisition, visualization, and analysis, this design integrates all functionalities into a single, compact platform powered by the Analog Devices AD5933 impedance converter and a Raspberry Pi 4. The design incorporates custom analog circuitry to extend the measurement range from 10 Hz to 100 kHz and supports a wide impedance spectrum through switchable feedback resistors. Validated against a benchtop impedance analyzer, the system demonstrates high accuracy with normalized root-mean-square errors (NRMSEs) of 1.41% and 3.77% for the impedance magnitude and phase of passive components, respectively, and 1.43% and 1.29% for the biopotential electrode evaluation and skin/electrode impedance measurement. This cost-effective solution, with a total cost of USD 159, addresses the accessibility challenges faced by smaller research labs and healthcare facilities, offering a compact, low-power platform for reliable impedance analysis in biomedical applications.

Keywords: AD5933; biopotential electrode; impedance analyzer; impedance measurement; portable; skin/electrode impedance.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
(a) Schematics of impedance converter board, (b) hardware architecture block diagram, and (c) components of impedance converter board.
Figure 2
Figure 2
Impedance analyzer system software algorithm.
Figure 3
Figure 3
Graphical user interface of impedance analyzer system.
Figure 4
Figure 4
Developed impedance analyzer system prototype: (a) front side; (b) back side.
Figure 5
Figure 5
(a) Test circuits used for impedance analyzer validation. (b) Measured impedance magnitude and (c) phase [circuit I (°), circuit II (°), and circuit III (°)] compared with the theoretical values (-).
Figure 6
Figure 6
(a) Ag/Agcl disposable electrodes; (b) two disposable electrodes attached in a gel-to-gel manner connected to the impedance analyzer system.
Figure 7
Figure 7
(a) Reusable Ag/Agcl electrode connected to A1, (b) reusable Ag/Agcl electrode connected to FPZ, and (c) comparison of impedance measurements from reference instrument and developed impedance analyzer system for skin/electrode impedance measurements.
Figure 8
Figure 8
Current consumption of impedance analyzer system.
See this image and copyright information in PMC

References

    1. Rao R.K., Sasmal S. Nanoengineered smart cement composite for electrical impedance-based monitoring of corrosion progression in structures. Cem. Concr. Compos. 2022;126:104348. doi: 10.1016/j.cemconcomp.2021.104348. - DOI
    1. Fuentes-Vélez S., Fagoonee S., Sanginario A., Gallo V., Riganti C., Pizzi M., Altruda F., Demarchi D. Impedance-based drug-resistance characterization of colon cancer cells through real-time cell culture monitoring. Talanta. 2021;222:121441. doi: 10.1016/j.talanta.2020.121441. - DOI - PubMed
    1. Murphy B.B., Scheid B.H., Hendricks Q., Apollo N.V., Litt B., Vitale F. Time Evolution of the Skin–Electrode Interface Impedance under Different Skin Treatments. Sensors. 2021;21:5210. doi: 10.3390/s21155210. - DOI - PMC - PubMed
    1. Albulbul A. Evaluating major electrode types for idle biological signal measurements for modern medical technology. Bioengineering. 2016;3:20. doi: 10.3390/bioengineering3030020. - DOI - PMC - PubMed
    1. Khalil S.F., Mohktar M.S., Ibrahim F. The theory and fundamentals of bioimpedance analysis in clinical status monitoring and diagnosis of diseases. Sensors. 2014;14:10895–10928. doi: 10.3390/s140610895. - DOI - PMC - PubMed

LinkOut - more resources