Vepa Jithendra
Philips Research Asia -Bangalore, Philips Innovation Campus, Bangalore, India.
Annu Int Conf IEEE Eng Med Biol Soc. 2009;2009:2539-42. doi: 10.1109/IEMBS.2009.5334810.
Murmurs are auscultatory sounds produced by turbulent blood flow in and around the heart. These sounds usually signify an underlying cardiac pathology, which may include diseased valves or an abnormal passage of blood flow. The murmurs are classified based on their occurrence in different parts of the heart cycle; systolic murmurs and diastolic murmurs. This paper investigates features derived from cepstrum of the heart sound signals and use them to train three classifiers; k-nearest neighbor (kNN) classifier, multilayer perceptron (MLP) neural networks and support vector machines (SVM) for classification of heart sounds into normal, systolic murmurs and diastolic murmurs. These features have been compared with features extracted from short-term Fourier transform (STFT) and discrete wavelet transform (DWT) in combination with the above three classifiers. The classification experiments were carried out on the heart sounds samples collected from various web sources. Among various combinations of the above features and classifiers, SVM trained on cepstral features are most promising for murmur classification with an accuracy of around 95%.
杂音是由心脏内部及周围的湍流血液产生的听诊声音。这些声音通常表明存在潜在的心脏病变,可能包括瓣膜疾病或血流异常通道。杂音根据其在心动周期不同阶段的出现情况进行分类,即收缩期杂音和舒张期杂音。本文研究了从心音信号的倒谱中提取的特征,并使用这些特征训练三个分类器:k近邻(kNN)分类器、多层感知器(MLP)神经网络和支持向量机(SVM),用于将心音分类为正常、收缩期杂音和舒张期杂音。这些特征已与从短时傅里叶变换(STFT)和离散小波变换(DWT)中提取的特征结合上述三个分类器进行了比较。分类实验是对从各种网络来源收集的心音样本进行的。在上述特征和分类器的各种组合中,基于倒谱特征训练的SVM在杂音分类方面最具前景,准确率约为95%。