一种循环频率域内的心音包络合成方法

Cardiac Sound Envelope Synthesis in Cycle Frequency Domain

在循环频率域内分析心音的特性,提出一种新的心音包络合成方法。采用循环统计量,研究心音的循环平稳特性,把心音包络表示为循环频率的线性和,线性系数由循环谱估计。以心音分裂为例,进行包络提取仿真。在加性高斯白噪声和随机干扰环境下,对各种包络提取方法进行对比分析。仿真结果表明,心音包络可以在循环频率域内合成。心音具有显著的循环平稳特征,心音包络可以表示成循环频率的线性和。所提出的方法不仅对心音包络的合成与分解给出物理解释,而且具有一定的抗噪声和抗干扰能力。

This study is aimed to analyze heart sounds in cycle frequency domain and investigate the synthesis method for envelope. Heart sound envelope was represented as the linear combination of cycle frequency, where the linear coefficient was estimated by cycle spectrum. As an example, envelope was extracted from heart sounds recording with soulds split. Comparison study was conducted for the proposed method and other envelope methods in additive Gaussian white noise and random interference. Numerical simulations showed that heart sound envelope could be synthesized and decomposed in cycle frequency domain. Heart sounds were strongly cyclic stationary. The most energy of cardiac sound was discretely distributed in cycle frequency domain. The proposed envelope synthesis model not only had physical meaning but also was robust to stationary noise and non-periodic interference.