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


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).


Active electrode Capacitive ECG Flexible electrode Unconstrained ECG measurement 



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.


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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

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