[The detection of non-stationary T-wave alternans: a modified correlation method].

T-wave alternans (TWA) refers to a phenomenon appearing in the surface electrocardiograph (ECG) as a consistent fluctuation in morphology and amplitude of the T wave on an "every-other-beat" basis. Correlation method (CM) has a certain ability to detect the non-stationary TWA, but it is very sensitive to noise. In this paper we propose a modified correlation method to ensure a stable and accurate detection of non-stationary TWA. Compared to the CM, the method modifies the judge condition and uses the linear fitting to limit the noise to gain the ability of detecting of non-stationary TWA. Our simulation and clinical data assessment study demonstrates the improved performance of the proposed algorithm.