Medical decision support system

摘要

A process for pre-processing recorded and digitized heart sounds and corresponding digitized ECG signals is provided. The pre-processed signals (203) are suitable for input into an automatic decision support system implemented by means of a diagnostic decision network (205), used for diagnosing and differentiation between normal/functional (206) and pathological (207) heart murmurs, particularly in pediatric patients. The process includes identifying or predicting locations of individual heart beats within the heart sound signal, identifying the positions of the S1 and S2 heart pulses within the respective heart beats, predicting and identifying the locations and durations of the systole and diastole segments of the heart beats (302), determining if segmentation of the heart sound signal is possible based on the selected and isolated heart beats (305), and the segmentation of the respective heart beats into segments for allowing better feature extraction. The invention also provides a process for detecting the QRS complex of an ECG signal for optimizing the number of heart beat cycles detected.

主权项

1. A computer-implemented process of pre-processing a heart sound signal of a patient's heart, the process being performed by a computing device and including:
a) receiving, by the computing device, at least one recorded heart sound signal of a patient's heart in the form of a digitized acoustic heart sound signal; b) identifying or predicting, by the computing device, locations of individual heart beats within the digitized acoustic heart sound signal; c) predicting, by the computing device, locations and durations for systole and diastole segments of the digitized acoustic heart sound signal; d) compiling, by the computing device, a peak array containing peak locations within the digitized acoustic heart sound signal that correspond to possible locations of S1 and S2 heart sound pulses in the digitized acoustic heart sound signal; e) calculating, by the computing device, interval sizes between the peak locations in the peak array; f) selecting and isolating, by the computing device, heart beats in the digitized acoustic heart sound signal that were detected with the highest level of confidence based on the predicted durations of the systole and diastole segments of the digitized acoustic heart sound signal and the peak array; g) determining, by the computing device, if segmentation of the digitized acoustic heart sound signal is possible based on the selected and isolated heart beats; h) if segmentation of the heart sound signal is found to be possible, dividing, by the computing device, inter-peak intervals that make up the digitized acoustic heart sound signal into even and odd groups in the order in which they appear; i) calculating, by the computing device, a variance and mean for both of the even and odd groups and designating the group with the largest ratio of variance over mean as corresponding to diastole intervals and the other group as corresponding to systole intervals; and j) outputting, by the computing device, the digitized acoustic heart sound signal with the selected and isolated heart beats and the designated diastole and systole intervals.