基于改进反向Mel频率倒谱系数的咳嗽干湿性自动分类  

Automatic Classification of Dry Cough and Wet Cough Based on Improved Reverse Mel Frequency Cepstrum Coefficients

作　　者：朱春媚[1,2] 刘保军[1] 黎萍[1] 莫鸿强[2] 郑则广[3] 

机构地区：[1]电子科技大学中山学院机电工程学院,中山528403 [2]华南理工大学自动化科学与工程学院,广州510641 [3]广州医学院第一附属医院,广州510120

出　　处：《生物医学工程学杂志》2016年第2期239-243,254,共6页Journal of Biomedical Engineering

基　　金：中央高校基本科研专项基金项目资助(2012ZZ0106);中山市科技计划项目资助(2014A2FC383)

摘　　要：咳嗽的自动分类在临床上具有重要的辅助诊断作用。传统的Mel频率倒谱系数(MFCC)采用Mel均匀滤波器组,高频段的滤波器分布较稀疏,未能最大程度反映两类咳嗽的特征差别。针对这个问题,本文在分析干性咳嗽和湿性咳嗽频谱能量分布特点的基础上,提出了一种改进的反向MFCC提取方法,采用反向Mel刻度上的均匀滤波器组,并放置在两类咳嗽都具有高频谱能量的频段,使得特征提取集中在两类咳嗽特征信息丰富且差别显著的频段进行。基于隐马尔可夫模型的咳嗽干湿性自动分类实验结果表明,该方法获得了优于传统MFCC的分类性能,总体分类准确率从89.76%提高到了93.66%。Automatic classification of different types of cough plays an important role in clinical.In the previous research of cough classification or cough recognition,traditional Mel frequency cepstrum coefficients（MFCC）which extracts feature mainly from low frequency band is usually used as feature expression.In this paper,by analyzing the distributions of spectral energy of dry/wet cough,it is found that spectral difference of two types of cough exits mainly in middle frequency band and high frequency band.To better reflect the spectral difference of dry cough and wet cough,an improved method of extracting reverse MFCC is proposed.In this method,reverse Mel filter-bank in which filters are allocated in reverse Mel scale is adopted and is improved by placing filters only in the frequency band with high spectral energy.As a result,features are mainly extracted from the frequency band where two types of cough show both high spectral energy and distinguished difference.Detailed process of accessing improved reverse MFCC was introduced and hidden Markov models trained by 60 dry cough and 60 wet cough were used as cough classification model.Classification experiment results for 120 dry cough and 85 wet cough showed that,compared to traditional MFCC,better classification performance was achieved by the proposed method and the total classification accuracy was raised from 89.76%to 93.66%.

关 键 词：计算机辅助诊断 咳嗽自动分类 特征提取 反向Mel频率倒谱系数 

分 类 号：R56[医药卫生—呼吸系统] TP391.7[医药卫生—内科学]