单边狭窄血管中超声多普勒信号的仿真研究

超声多普勒技术作为一种无损检测手段被广泛应用于血管狭窄的检测。以往的血管狭窄仿真信号的研究仅限于双边狭窄的对称情况,文章提出了一种单边狭窄血管中超声多普勒信号的仿真方法。首先用有限元分析方法(FEM)计算出狭窄血管中血流流速场分布情况,然后用总体分布非参数估计法计算出超声多普勒信号的功率谱密度(PSD),再用余弦叠加法获取仿真的超声多普勒时域信号。用快速傅里叶变换(FFT)计算仿真超声多普勒信号的频谱,从中计算最大频率、平均频率和频谱宽度等参数,分析它们在不同流速和狭窄程度下的特征,为血管疾病的诊断提供敏感的参数。

Simulation studies on Doppler ultrasound signals in asymmetric stenosed vessels

As a non-invasive method,the Doppler ultrasound technique is used to detect vessel stenosis.Doppler ultrasound signals from symmetric-stenosed vessels have already been studied.A computer simulation method is proposed in this paper to generate Doppler ultrasound signals from vessels with asymmetric stenosis.The blood flow velocity distribution in a stenosed vessel is first calculated using the transient finite element method(FEM).Power spectral density(PSD) of the Doppler signals is estimated using an overall-distribution nonparametric estimation method.Finally the Doppler signals are generated using the cosine-superposed method.The maximum frequency,the mean frequency and the spectral bandwidth are calculated from the spectra,used to analyze the characteristics of Doppler signals from stenosed vessels with different degrees of stenoses and flow velocities.From this sensitive parameters can be found for detection of vessel diseases.