An analysis on the effect of the shape features of the textile electrode on the non-contact type of sensing of cardiac activity based on the magnetic-induced conductivity priciple

The purpose of this research is to analyze the effect of shape of the inductive textile electrode on the non-contact heart activity sensing, based on the magnetic-induced conductivity principle. Four types of the inductive textile electrodes were determined according to the combinations of the two shape features. A fiber-metal hybrid-typed conductive thread was developed and applied to materialization of the textile electrodes by embroidery method. The heart activity was extracted through the textile electrode sewn on a T-shirt. The experiments were implemented to constantly measure the heart activity for 20 seconds, in each case of 5 healthy male subjects. The heart activity signals acquired in each type of the inductive textile electrode were analyzed, 1) by drawing a comparison of morphology with those of ECG signal (Lead II), and 2) by calculation of the normalized mean and standard deviation of magnitude of the heart activity signals. The analysis resulted that the relatively better quality of signals were acquired in the 'square' types in the matter of whole shape, while the better results were obtained in 'donut' types in the matter of center hole. Accordingly, the relatively best quality of signals was obtained in the case of 'Square-Donut' type of the inductive textile electrode.