Non-obtrusive monitoring of narrow-band electrocardiogram with a capacitive electrode unit during sleep

Abstract

An approach is proposed for obtaining electro-cardiographic potential from adult lying with underwear and pajamas during sleep. This method is based on capacitive coupling involving the electrode, the cloth and the skin. A developed device was fabricated to explore the feasibility of the approach and evolution experiments were conducted for 5 men. Validation of the system revealed the following: (1) The frequency response of the device with underwear and pajamas revealed that the gain of the detected signal was reduced. (2) The signal displayed a periodic waveform synchronized with the simultaneously recorded ECG, even when underwear and pajamas was inserted between the electrode and the skin. ECG signal can be measured even all body position. (3) In overnight measurement, detection rate of R-wave for each subject was more than 95 %. Although there is still room for improvement in terms of its practical use, the developed device appears promising for application to bedding as a non-obtrusive and awareness-free method for ECG monitoring during sleep. © 2009 Springer-Verlag.