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
. 2016 Aug 24;3(3):20.
doi: 10.3390/bioengineering3030020.

Evaluating Major Electrode Types for Idle Biological Signal Measurements for Modern Medical Technology

Anas Albulbul  1
Affiliations

Evaluating Major Electrode Types for Idle Biological Signal Measurements for Modern Medical Technology

Anas Albulbul. Bioengineering (Basel). .

Abstract

Biological signals such as electrocardiogram (ECG) and electromyography (EMG) that can be measured at home can reveal vital information about the patient's health. In today modern technology, the measured ECG or EMG signals at home can be monitored by medical staff from long distance through the use of internet. Biopotential electrodes are crucial in monitoring ECG, EMG, etc., signals. Applying the right type of electrode that lasts for a long time and assists in recording high signal quality is desirable in medical devices industry. Three types of electrodes (Silver/Silver Chloride (Ag/AgCl) electrodes, Orbital electrodes and Stainless steel electrodes) were tested to identify the most appropriate one for recording biological signals. The evaluation was based on determining the electrode circuit model components and having high capacitance value or high capacitor value of electrode circuit model (Cd) and low electrode-skin impedance value or low resistor value of electrode circuit model (Rd). The results revealed that Ag/AgCl is the best type of electrodes, followed by Orbital electrodes. Stainless steel electrodes had performed poorly. However, Orbital electrodes material can last longer than Ag/AgCl and hence perform similar to Ag/AgCl electrodes, which can be idle for monitoring biological signals at home without the need for medical staff to replace the electrodes in a short period of time.

Keywords: biological signals; electrode-skin impedance; electrodes; noise.

PubMed Disclaimer

Conflict of interest statement

The author declares no conflict of interest.

Figures

Figure 1
Figure 1
Orbital electrode’s penetration into the skin layers during bio-signal recording.
Figure 2
Figure 2
(a) Ag/AgCl electrode (electrode’s snap side); (b) Ag/AgCl electrode (electrode’s skin side).
Figure 3
Figure 3
(a) Orbital electrode (electrode’s kin side); (b) Orbital electrode (electrode’s snap side).
Figure 4
Figure 4
(a) Stainless steel electrode (electrode’s skin side); (b) Stainless steel electrode (electrode’s snap side).
Figure 5
Figure 5
The simplified schematic diagram for the electrodes system used in the study.
Figure 6
Figure 6
Equivalent circuit model for electrode-skin interface.
Figure 7
Figure 7
Experimental results for Orbital electrode-skin impedance frequency response (Subject, Orbital-S2) and the model plot. Estimated electrode circuit components values are located at the top of the Figure.
Figure 8
Figure 8
Pregelled Ag/AgCl, Orbital and Stainless Steel electrode’s circuit model components average Log values with standard deviation for all the tested subjects; (A) Rd; (B) Cd and (C) Rs.
See this image and copyright information in PMC

References

    1. Grimnes S., Martinsen Ø.G. Bioimpedance and Bioelectricity Basics. 2nd ed. Elsevier Ltd.; San Diego, CA, USA: 2008. pp. 40–270.
    1. Yamamoto Y., Yamamoto T. Dispersion and correlation of the parameters for skin impedance. Med. Biol. Eng. Comput. 1978;16:592–594. doi: 10.1007/BF02457817. - DOI - PubMed
    1. Mcadams E.T., Jossinet J., Lackermeier A., Risacher F. Factors affecting electrode-gel-skin interface impedance in electrical impedance tomography. Med. Biol. Eng. Comput. 1996;34:397–408. doi: 10.1007/BF02523842. - DOI - PubMed
    1. Rosell J., Colominas J., Riu P., Pallas-Areny R., Webster J. Skin Impedance from 1 Hz to 1 MHz. IEEE Trans. Biomed. Eng. 1988;35:649–651. doi: 10.1109/10.4599. - DOI - PubMed
    1. Webster J.G. Medical Instrumentation Application and Design. 4th ed. John Wiley & Sons; New York, NY, USA: 2010. pp. 189–235.