Naseri H, Homaeinezhad M R
Department of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, Iran.
J Med Eng Technol. 2012 Aug;36(6):308-18. doi: 10.3109/03091902.2012.684832. Epub 2012 Jun 1.
The major focus of this study is to describe and develop a phonocardiogram (PCG) signal measurement binary quality assessment (accept-reject) technique. The proposed algorithm is composed of three major stages: preprocessing, numerical-based quality measurement and advanced measurement subroutines. The preprocessing step includes normalization, wavelet-based threshold denoising and baseline wander removal. The numerical-based quality measurement routine includes two separate stages based on energy and level of noise of the PCG signal. The advanced quality measurement step is mainly based on the interval of S1 and S2 sounds. The proposed technique was applied to 400 2-min PCG signals gathered by volunteers with range of skills in PCG data acquisition from patients with different types of valve diseases from their 2R (aortic), 2L (pulmonic), 4R (apex) and 4L (tricuspid) positions by implementing an electronic stethoscope (3M Littmann(®) 3200, 4 kHz sampling frequency). The dataset was firstly annotated manually and then, by applying the proposed algorithm, an accuracy of 95.25% was achieved.
本研究的主要重点是描述和开发一种心音图（PCG）信号测量二元质量评估（接受-拒绝）技术。所提出的算法由三个主要阶段组成：预处理、基于数值的质量测量和高级测量子程序。预处理步骤包括归一化、基于小波的阈值去噪和基线漂移去除。基于数值的质量测量程序包括基于PCG信号能量和噪声水平的两个独立阶段。高级质量测量步骤主要基于S1和S2声音的间隔。通过使用电子听诊器（3M Littmann(®) 3200，4 kHz采样频率），从患有不同类型瓣膜疾病的患者的2R（主动脉）、2L（肺动脉）、4R（心尖）和4L（三尖瓣）位置采集PCG数据，所提出的技术应用于400个2分钟的PCG信号，这些信号由具有不同PCG数据采集技能的志愿者收集。首先对数据集进行人工标注，然后通过应用所提出的算法，准确率达到了95.25%。
