Effect of method and parameters of spectral analysis on selected indices of simulated Doppler spectra

Abstract

The sensitivity of Doppler spectral indices (mean frequency, maximum frequency, spectral broadening index and turbulence intensity) to the conditions of spectral analysis (estimation method, data window, smoothing window or model order) increases with decreasing signal bandwidth and growing index complexity. The bias of spectral estimate has a more important effect on these indices than its variance. A too low order, in the case of autoregressive modeling and minimum variance methods, and excessive smoothing, in the case of the FFT method, result in increased errors of Doppler spectral indices. There is a trade-off between the errors resulting from a short data window and those due to insufficient temporal resolution.

Packets Wavelets and Stockwell Transform Analysis of Femoral Doppler Ultrasound Signals

“…The wavelet transforms utilize a set of analytical functions built by expansion / compression and translation of a function called mother wavelet. In our study, we chose the Morlet wavelet that has a similar form to Doppler ultrasound signals [20].…”

Time Frequency Analysis of Femoral Doppler Ultrasound Signals by AR Modelling

“…There are also a certain number of original approaches introduced by "Forsberg" and "Strong" et. al, who use decomposition in singular values to evaluate the Doppler frequency [2][3][4][5]. In order to value the parametric signal time-frequency plan, we rewrite the equation under the following matrix form:…”