Instantaneous Frequency Analysis of Diastolic Murmurs For Coronary Artery Disease

The instantaneous frequency estimate of diastolic murmurs is proposed for detection of coronary artery disease. On the basis of analyzing the relation between the coronary artery occlusions and the diastolic murmurs, Hilbert Huang transform is studied, which can make accurate instantaneous frequency estimate by empirical mode decomposition and Hilbert transform. Heart sounds have been recorded from patients with coronary artery disease before and after angioplasty. Hilbert Huang transform is carried out on each isolated diastolic phase to acquire instantaneous frequency. The results have shown that the instantaneous frequencies have obvious difference between patients before and after angioplasty. Instantaneous frequency of diastolic murmurs provides a strong basis for detection of coronary artery disease.