Advertisement

Thin and flexible active electrodes with shield for capacitive electrocardiogram measurement

  • Seung Min Lee
  • Kyo Sik Sim
  • Ko Keun Kim
  • Yong Gyu Lim
  • Kwang Suk ParkEmail author
Original Article

Abstract

Capacitive electrocardiogram (ECG) measurement over clothing requires large electrodes that can remain in contact with curved body surfaces to increase the signal-to-noise ratio (SNR). In this article, we propose a new, thin, and flexible active electrode for use as a capacitive ECG measurement electrode. This electrode contains a shielding plate over its surface and it is extremely thin and can bend freely to cover larger body surfaces of the curve-shaped human torso. We evaluated the characteristics of flexible active electrodes under conditions of varying cloth thickness, electrode size, and contacting pressure. Electrodes of two sizes (45 and 12 cm2) were attached to a chest belt to measure the ECG from the human torso, and the results obtained for both the sizes were compared. Cloth thickness and electrode size showed a dominant effect on the SNR, whereas contacting pressure had almost no effect. The flexible active electrodes attached to chest belts wrapped closely and uniformly over the curved surface of the torso and SNR was increased with an increase in electrode size. Although the ECG signal became more distorted as the cloth thickness increased, the larger-sized flexible active electrode (45 cm2) showed less distortion than the smaller-sized one (12 cm2).

Keywords

Active electrode Capacitive ECG Flexible electrode Unconstrained ECG measurement 

Notes

Acknowledgment

This work was supported in part by MCIE through the Core Technology Development Program and in part by the Advanced Biometric Research Center, MOST/KOSEF, Republic of Korea.

References

  1. 1.
    Andreoni G, Pedotti A, Rienzo MD (2000) ECG monitoring through environmental electrodes. Paper presented at the Annual International Conference of IEEE EMBS, Hong KongGoogle Scholar
  2. 2.
    Baxter LK (1997) Capacitive sensors design and applications. IEEE Press, New York, pp 147–176Google Scholar
  3. 3.
    Guyton AC, Hall JE (2000) Textbook of medical physiology, 10th edn. Saunders, St Louis, pp 107–151Google Scholar
  4. 4.
    Ishijima M (1993) Monitoring of electrocardiograms in bed without utilizing body surface electrodes. IEEE Trans Biomed Eng 40(6):593–594CrossRefGoogle Scholar
  5. 5.
    Ji Z, Dong X, Shi X, You F, Fu F, Liu R (2009) Novel electrode-skin interface for breast electrical impedance scanning. Med Biol Eng Comput 47(10):1045–1052CrossRefGoogle Scholar
  6. 6.
    Lim YG, Kim KK, Park KS (2006) ECG measurement on a chair without conductive contact. IEEE Trans Biomed Eng 53(5):956–959CrossRefGoogle Scholar
  7. 7.
    Lim YG, Kim KK, Park KS (2007) ECG recording on a bed during sleep without direct skin contact. IEEE Trans Biomed Eng 54(4):718–725CrossRefGoogle Scholar
  8. 8.
    Lopez A Jr, Richardson PC (1969) Capacitive electrocardiographic and bioelectric electrodes. IEEE Trans Biomed Eng BME-16(1):99CrossRefGoogle Scholar
  9. 9.
    Metting van Rijn AC, Peper A, Grimbergen CA (1990) High-quality recording of bioelectric events part 1: interference reduction, theory and practice. Med Biol Eng Comput 28:389–397CrossRefGoogle Scholar
  10. 10.
    Neuman MR (1978) Biopotential amplifiers. In: Webster JG (ed) Medical instrumentation: application and design. Houghton Mifflin, BostonGoogle Scholar
  11. 11.
    Rantanen V, Niemenlehto PH, Verho J, Lekkala J (2010) Capacitive facial movement detection for human-computer interaction to click by frowning and lifting eyebrows: assistive technology. Med Biol Eng Comput 48(1):39–47CrossRefGoogle Scholar
  12. 12.
    Reitz JR, Milford FJ, Christy RW (1993) Foundations of electromagnetic theory, 4th edn. Addison-Wesley, Reading, pp 141–161Google Scholar
  13. 13.
    Rissanen SM, Kankaanpää M, Meigal A, Tarvainen MP, Nuutinen J, Tarkka IM, iraksinen O, Karjalainen PA (2008) Surface EMG and acceleration signals in Parkinson’s disease: feature extraction and cluster analysis. Med Biol Eng Comput 46(9):849–858CrossRefGoogle Scholar
  14. 14.
    Seo JW, Park KS (2003) ECG monitoring in beds via Bluetooth. Paper presented at the IEEE EMBS Asia-Pacific conference of biomedical engineering, Kyoto, JapanGoogle Scholar
  15. 15.
    Seo W, Ryu MS, Park KS, Jeong DU (2003) A home-based bedside monitoring system of ECG via Bluetooth protocol. Paper presented at the IEEE EMBS Asia-Pacific conference of biomedical engineering, Kyoto, JapanGoogle Scholar
  16. 16.
    Szucs K, Navalgund A, Borstad JD (2009) Scapular muscle activation and co-activation following a fatigue task. Med Biol Eng Comput 47(5):487–495CrossRefGoogle Scholar
  17. 17.
    Tamura T, Yoshimura T, Nakajima K, Miike H, Togawa T (1997) Unconstrained heart-rate monitoring during bathing. Biomed Instrum Technol 31:391–396Google Scholar
  18. 18.
    Ueno A, Akabane Y, Kato T, Hoshino H, Kataoka S (2007) Capacitive sensing of electrocardiographic potential through cloth from the dorsal surface of the body in a supine position: a preliminary study. IEEE Trans Biomed Eng 54(4):759–766CrossRefGoogle Scholar
  19. 19.
    Winter BB, Webster JG (1983) Reduction of interference due to common mode voltage in biopotential amplifiers. IEEE Trans Biomed Eng 30(1):58–62CrossRefGoogle Scholar

Copyright information

© International Federation for Medical and Biological Engineering 2010

Authors and Affiliations

  • Seung Min Lee
    • 1
    • 2
  • Kyo Sik Sim
    • 2
  • Ko Keun Kim
    • 2
    • 3
  • Yong Gyu Lim
    • 4
  • Kwang Suk Park
    • 5
    Email author
  1. 1.Graduate Program in BioengineeringSeoul National UniversitySeoulRepublic of Korea
  2. 2.Advanced Biometric Research CenterSeoul National UniversitySeoulRepublic of Korea
  3. 3.Interdisciplinary Program in Medical and Biological EngineeringSeoul National UniversitySeoulRepublic of Korea
  4. 4.Department of Oriental Biomedical EngineeringSangji UniversityGangwondoRepublic of Korea
  5. 5.Department of Biomedical Engineering, College of MedicineSeoul National UniversitySeoulRepublic of Korea

Personalised recommendations