Objective To propose a distribution feature extraction algorithm based on wavelet packet coefficients to reconstruct the signal energy sequence for effectively identifying the pathological features of heart sounds,thereby realizing the early screening of heart diseases.Methods The original heart sound signal was decomposed into 10 layers using wavelet packet decomposition algorithm.After obtaining the wavelet packet coefficients of each layer,each coefficient was reconstructed,and the energy of the reconstructed signal was calculated and arranged in the original order to form the energy sequence.The distribution characteristics of the energy sequence of the reconstructed signals at each layer were analyzed,and distribution features were taken as classification features.Support vector machine,K-nearest neighbor,and decision tree were used to classify and recognize normal heart sounds and the heart sound signals of various diseases.Results The combination of the distribution features of the reconstructed signal energy sequence and decision tree classifier had an accuracy of 93.6%for classifying 5 types of heart sounds on the public dataset,and the accuracy was 95.6%for identifying normal heart sounds and hypertrophic cardiomyopathy heart sounds.Conclusion The proposed algorithm can extract the effective pathological information of abnormal heart sounds,providing a reference for clinical cardiac auscultation.

With human placed in the whole nature, by following the biologic evolution path, the property of channel structure for "imprinting template" in meridian andwas explored with supramolecular chemistry. In the history of biologic evolution, each molecule in "molecule society" gradually developed into various highly-ordered supramolecular bodies based on self-identification, self-assembly, self-organization, self-replicating of"imprinting template", and thereby the original biochemical system was established, and finally evolved into human. In the forming process of supramolecular bodies, the channel structure of"imprinting template" in guest supramolecular bodies would be kept by host supramolecular bodies, and communicate with the outside to exchange materials, energy, information, otherwise life phenomenon could not continue, for which it was the chemical nature of biolo-gical supramolecular bodies for body to develop meridian. Therefore, the human was a gigantic and complicated supramolecules body in biological nature, and possessed the supramolecules "imprinting template" at each stage of evolution, for which the meridians were formed. When meridians converged, acupoints appeared; when acupointsconverged,appeared. With the promotion of the blood from heart, according to"imprinting template", the guest supramolecular bodies and host meridian produced-analysis, which was the-phenomenon of guest in meridian. It presented asimage of physiology and pathology as well as action regularities of medication and acupuncture tolerance, by which current various meridian viewpoints could be explained and propose the hypothesis of meridian supramolecular bodies. The meridian and its phenomenon was decide by its "imprinting template" of supramolecular bodies and self-reaction regularities, which abided through the living nature. This was the substance for meridian biology.