Analysis of the T wave alternans phenomenon with ECG amplitude modulation and baseline wander

In the work presented here we propose a new approach for the TWA modelling and detection. For this aim, the ECG amplitude modulation and the baseline wander in the ST-T segment are approximated by a scaling factor applied to the T wave added to a constant. Thanks to this simplification, the proposed global model of each ST-T segment is constituted by the scaled T wave, an offset and the shape of the alternans. Note that since these components are unknown, the problem of the estimation is ill posed. In addition to the modelling we also introduce a method to address the problem of the estimation of the T wave, the offset and the alternans shape and their respective coefficients. Thus, a model-based detector can be derived such as the generalized likelihood ratio test. Through this detection scheme, the orthogonality of the models is addressed and solved by imposing some constraints. Since the application of the constraints is driven by a student-t test, this hybrid detector will take advantage of both approaches.