A Study on Mean Frequency Estimation of Doppler Blood Signal

• Main Authors: Hsieh, Yu-Tao, 謝雨滔
• Other Authors: Wen-Whei Chang
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/58625351359495438744

碩士 === 國立交通大學 === 電信研究所 === 85 === Two significant building blocks in Color Flow Imaging systems have been discussed in this study. The first part is dedicated to clutter suppression. When the clutter is dominant as is normal in clinical environment, FIR or IIR high-pass filters are used to suppress the low-frequency clutter component. Simulation results show that the transient effect can be mitigated even when very short data sequence was available to the IIR filter whose registers have been well-initialized. Another topic is concerned with mean frequency estimation of Doppler blood flow. Emphasis is placed on the AC (AutoCorrelation) and AR (AutoRegressive) methods. The AC estimator is easy to implement and superior to the conventional FFT estimator, but it lacks the capability of distinguishing between blood flow and clutter. By mapping phases to the spectral peaks of the backscattered signal, an AR estimator has the advantage of reliable estimation of blood flow without clutter suppression.