New algorithms for pattern recognition of atrial fibrillation and sinus rhythm

Various zero-crossing techniques are used to distinguish between sinus rhythm and atrial fibrillation of different patients. The methods are threshold crossings, sine-wave crossings, threshold crossings of the derivative of the signal, and fast Fourier transform (FFT) analysis. The comparison shows that the sine-wave crossing method is best, because there is no need to normalize or to differentiate the signal (differentiation as a means to remove the DC component is a noisy process). Also, the algorithm is in real time (unlike the FFT procedure) and simple to implement