Detection of quiescent phases in echocardiography data using non-linear filtering and boundary detection

In order to detect the quasi-stationary states of the heart within a cardiac cycle from echocardiography data, we present an algorithm that uses non-linear filtering and boundary detection. The non-linear filtering algorithm involves anisotropic diffusion to remove the speckle noise from the data and to smoothen the homogeneous regions while preserving the edges. Following this, we perform binary thresholding and boundary detection, and observe the positional changes in the region of interest. From a series of echocardiography images, we derived the regions of cardiac quiescence, which we then plotted on the electrocardiograph (ECG) R-R interval. It is observed that the quiescence occurs in the diastolic region of the ECG signal, but the position and length of quiescence varies across multiple cardiac cycles for the same individual.