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
. 2017 Jan 1;7(1):2.
doi: 10.3390/bios7010002.

Design and Development of Non-Contact Bio-Potential Electrodes for Pervasive Health Monitoring Applications

Anthony J Portelli  1 , Slawomir J Nasuto  2
Affiliations

Design and Development of Non-Contact Bio-Potential Electrodes for Pervasive Health Monitoring Applications

Anthony J Portelli et al. Biosensors (Basel). .

Abstract

For the advent of pervasive bio-potential monitoring, it will be necessary to utilize a combination of cheap, quick to apply, low-noise electrodes and compact electronics with wireless technologies. Once available, all electrical activity resulting from the processes of the human body could be actively and constantly monitored without the need for cumbersome application and maintenance. This could significantly improve the early diagnosis of a range of different conditions in high-risk individuals, opening the possibility for new treatments and interventions as conditions develop. This paper presents the design and implementation of compact, non-contact capacitive bio-potential electrodes utilising a low impedance current-to-voltage configuration and a bootstrapped voltage follower, demonstrating results applicable to research applications for capacitive electrocardiography and capacitive electromyography. The presented electrodes use few components, have a small surface area and are capable of acquiring a range of bio-potential signals.

Keywords: capacitive; electrodes; non-contact; wireless.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Diagram of the layers of the basic design of a capacitive sensor on a PCB.
Figure 2
Figure 2
Schematic of the low impedance capacitive sensor design with highlighted T-network Req.
Figure 3
Figure 3
Schematic of the high impedance design configuration showing bootstrapped front end (A); and voltage follower (B).
Figure 4
Figure 4
System configuration.
Figure 5
Figure 5
The gain and phase response of Ag/AgCl electrodes (blue) compared against the low impedance electrode (red) and high impedance (green).
Figure 6
Figure 6
The gain at 10 Hz and phase at measured at 10 Hz with varying distances for the current-to-voltage converter (Red) and Bootstrapped electrode (Green).
Figure 7
Figure 7
Left shows similarity plots of the capacitive electrode data, Bootstrapped electrode (top); and current-to-voltage converter (bottom). Right shows raw 1 s excerpts of the bio-potential recordings (blue Ag/Cl, green capacitive electrode).
Figure 8
Figure 8
Comparison of electromyographic recordings taken from the right forearm of a male participant. AgCl vs. current-to-voltage converter electrode (A); and Agcl vs. bootstrapped electrode (B). The AgCl electrode recordings have been displaced for clarity.
See this image and copyright information in PMC

References

    1. Blankertz B., Popescu F., Krauledat M., Fazli S. Challenges for Brain-Computer Interface Research for Human-Computer Interaction Applications; Proceedings of the CHI Workshop on Brain-Computer Interfaces for HCI and Games; Florence, Italy. 5–10 April 2008; pp. 5–8.
    1. Prutchi D., Norris M. Design and Development of Medical Electronic Instrumentation. John Wiley and Sons; Hoboken, NJ, USA: 2004. p. 478.
    1. Lopez A., Richardson P.C. Capacitive electrocardiographic and bioelectric electrodes. IEEE Trans. Biomed. Eng. 1969;16:99. doi: 10.1109/TBME.1969.4502613. - DOI - PubMed
    1. Guger C., Krausz G., Edlinger G. Brain-Computer Interface Control with Dry EEG Electrodes; Proceedings of the 5th International Brain-Computer Interface Conference; Graz, Austria. 22–24 September 2011; pp. 316–319.
    1. Bergey G.E., Squires D., Sipple W.C. Electrocardiogram Recording with Pasteless Electrodes. IEEE Trans. Biomed. Eng. 1971;BME–18:206–211. doi: 10.1109/TBME.1971.4502833. - DOI