Comparison of time-frequency distribution techniques for analysis of simulated Doppler ultrasound signals of the femoral artery
Comparison of time-frequency distribution techniques for analysis of simulated Doppler ultrasound signals of the femoral artery
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DOI：
10.1109/10.284961
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发表时间：
1994-04
影响因子：
4.6
通讯作者：
Zhenyu Guo;L. Durand;H. C. Lee
中科院分区：
文献类型：
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作者：
Zhenyu Guo;L. Durand;H. C. Lee
多普勒超声血流信号的时频分布通常采用短时傅里叶变换或自回归模型计算。这两种技术要求信号在有限区间内保持平稳。这个要求对分布估计施加了一些限制。在本研究中，测试了三种新的非平稳信号分析技术（Choi-Williams分布、减少干扰分布和Bessel分布），以确定它们在分析多普勒股动脉血流信号中的优势和局限性。为了进行比较，建立了正交多普勒信号模拟模型，并根据理论分布对各技术参数进行了优化。使用这些新技术计算的分布进行了评估，并与使用短时傅里叶变换和自回归建模计算的分布进行了比较。用相关系数、积分平方误差和平均频率波形的归一化均方根误差三个指标来评价每种技术的性能。结果表明，贝塞尔分布表现最好，但Choi-Williams分布和自回归建模也能产生较好的多普勒信号时频分布
The time-frequency distribution of the Doppler ultrasound blood flow signal is normally computed by using the short-time Fourier transform or autoregressive modeling. These two techniques require stationarity of the signal during a finite interval. This requirement imposes some limitations on the distribution estimate. In the present study, three new techniques for nonstationary signal analysis (the Choi-Williams distribution, a reduced interference distribution, and the Bessel distribution) were tested to determine their advantages and limitations for analysis of the Doppler blood flow signal of the femoral artery. For the purpose of comparison, a model simulating the quadrature Doppler signal was developed, and the parameters of each technique were optimized based on the theoretical distribution. Distributions computed using these new techniques were assessed and compared with those computed using the short-time Fourier transform and autoregressive modeling. Three indexes, the correlation coefficient, the integrated squared error, and the normalized root-mean-squared error of the mean frequency waveform, were used to evaluate the performance of each technique. The results showed that the Bessel distribution performed the best, but the Choi-Williams distribution and autoregressive modeling are also techniques which can generate good time-frequency distributions of Doppler signals.>