Flexible Concentric Ring Electrode for Non Invasive Bioelectrical Surface Recordings

Abstract

Abstract Non-invasive bioelectrical recordings are usually carried out by using monopolar or bipolar disc electrodes. The poor spatial resolution is one important disadvantage of this kind of electrodes tending to pick up physiological interferences. Concentric ring electrodes have already been implemented in rigid substrates to increase the spatial resolution in the recording of bioelectrical signals such as the electrocardiography (ECG) or the electroencephalography (EEG). Our goal was to develop and test a new modular active sensor made up of a disposable sensing part with concentric ring electrodes printed on a flexible substrate by thick-film technology connected to a battery powered signal conditioning circuit, and to compare it to rigid conventional concentric ring electrodes implemented on printed circuit board. Simultaneous ECG recordings were carried out using both flexible and rigid electrodes. Results show that flexible concentric ring electrodes present lower skin-electrode contact impedance, higher amplitude and lower baseline wander than the rigid ones.