Patent ID: 7001338
Filing Date: 2006-02-21
Classification: A61B

Abstract:
1. A method of diagnosing pathologic heart conditions comprising: parsing a time series of heart sounds into a sequence of individual heart cycles; determining the systolic interval of the heart cycles; identifying a subinterval for each systolic interval of the heart cycles; filtering the time series of heart sounds using a time-frequency transformation; identifying anomalously high wavelet coefficients using a constant false alarm rate (CFAR) detector; assembling the series of anomalously high detections into a matrix; convolving the matrix with an averaging vector, said vector's length derived from the expected time spread of a click occurrence, the convolution yielding detection statistics across heart cycles and time intervals consistent with an observed spread of click occurrence times; calculating a click score as the maximum element of a vector formed by the median wavelet coefficient amplitude across heart cycles squared at each time sample multiplied element-wise by a vector formed by the sum across heart cycles of the number of detections at each time sample; and comparing the click score to a threshold level in order to distinguish between a normal heart and a pathologic heart.