关键词: 呼吸音, Hilbert变换, 复小波变换, 包络提取

Abstract: As the respiratory sound signals are transient and with broad band，an envelope feature extraction method based on complex wavelet transform of respiratory sounds is proposed on the basis of analyzing the shortcomings of Hilbert transform method.Gain the envelope by doing Morlet wavelet transform of respiratory sounds after preprocessing.Extract the statistics and energy of envelope to form the feature vectors of BP neural network.The classification rate is satisfactory.The research findings show that this feature extraction method of respiratory sounds is fairly efficient.

Key words: respiratory sounds, Hilbert transform, complex wavelet transform, envelope extraction