Complex detection and subtraction via wavelet, a new atrial activity extracting algorithm

In this paper, a new technique for extracting the Atrial Activity (AA) using a single-lead from surface ECG and based on Wavelet transform and adaptive filtering, is presented. Firstly, the fiducial points of each beat are detected using a Discrete Wavelet Transform (DWT). In the second stage, the dominant frequency (Fp) of the f waves segments is calculated, allowing the application of an adaptive filtering. Averaging this signal with a median complex based on Template Matching and Subtraction cancellation technique (TMS) results a signal where AA is minimum. Finally, a subtraction between the original lead and the averaged signal produces a residual signal which contains the expected AA. The presented results show that Complex Detection and Subtraction via Wavelet (CDSW) can be a highly efficient tool for the study of atrial arrhythmias in those systems with reduced number of leads, like Holter recording systems.