An algorithm for evaluating the quality of the electrocardiosignal

The main objective of this study is to introduce a simple, low-complexity and effective algorithm to evaluate the quality of the real-time electro-cardiosignal, especially the electro-cardiosignal coming from dry electrode, or the signal collecting during periods of muscular activity or excessive motion. In the proposed method, the real-time signal is pre-processed by five main steps:(1) down sampling to reduce the computation complexity; (2) three-order auto-correlation operation to compute the degree of correlation of the electrocardiogram; (3) finding two maximal values in the definite window size; (4) recording every maximal value´s position and amplitude; (5) analysing the relationship between every maximum´s position and amplitude. Finally, according to the judgment rules, the quality of electro-cardiosignal is obtained. The theory of the proposed algorithm is proved based on the mathematics theory, and testified by the three real-time electrocardiosignal coming from the dry electrodes, which are the signal approximately with least noise, the signal with partial noise, and the signal with full bandwidth noise. The whole computation complexity is O(n²). The result shows this method can provide a better discrimination between noise and other signal.