ABSTRACT
Objective To extract envelope of heart sounds exactly,for the purpose of the further analysis of its characteristics.Methods The way that envelope extraction of heart sounds based on key-points was given.The points of local peak and valley were calculated firstly,and then heart sound envelope was gotten by the interpolation of these points.Results Compared with the envelope extracted by Hilbert-transform and mathematical morphology,respectively,the outline of heart sounds was extracted more accurately,and its time-domain characters were acquired by this method.Conclusion The envelope of heart sound is extracted correctly by this method,which is useful for the further analysis.
ABSTRACT
Objective Based on the analysis of time domain of heart sound with envelop to extract the envelope character of heart sounds.Methods The envelope extraction of heart sounds based on Hilbert-Huang Transform was given.Firstly,the original heart sounds signal was preprocessed by Huang Transform.Secondly,the envelope of heart sounds was got with Hilbert Transform.Results The first heart sound and the second heart sound were extracted,and all kinds of characters in time domain of heart sound were acquired more accurately.Conclusion The envelope of heart sound is extracted correctly.The foundation for further analysis of heart sounds is established.