改进的最小方差算法在超声成像中的应用

发布时间：2018-04-14 12:21

本文选题：最小方差 + 超声成像　；参考：《声学学报》2017年02期

【摘要】：为了提高最小方差超声成像算法的分辨率、对比度以及对噪声的鲁棒性,提出一种改进的最小方差成像算法。该方法首先基于回波信号中期望信号与噪声信号的可分离性将信号划分为期望信号和噪声信号,然后根据最小方差原理,求出加权向量使期望信号功率最小,同时,为了增加算法对噪声的鲁棒性,对信号方向向量增加一对约束条件,进一步提高图像质量。在全发全收和合成孔径模式下对点目标和吸声斑进行仿真,结果表明所提算法在全发全收模式下,-6 dB处分辨率在最小方差基础上提高了1倍左右,在合成孔径模式下,对比度在特征空间最小方差算法基础上提高了8 dB,且远优于传统延时叠加算法。最后通过实验进一步表明改进的最小方差算法图像在分辨率、对比度及对噪声的鲁棒性等方面表现更优,可以有效的改善超声图像的质量。
[Abstract]:In order to improve the resolution, contrast and robustness to noise of the minimum variance ultrasonic imaging algorithm, an improved minimum variance imaging algorithm is proposed.Based on the separability of the desired signal and the noise signal in the echo signal, the method divides the signal into the desired signal and the noise signal. Then, according to the principle of minimum variance, the weighted vector is obtained to minimize the power of the desired signal, and at the same time, the minimum power of the desired signal is obtained.In order to increase the robustness of the algorithm to noise, a pair of constraints are added to the signal direction vector to further improve the image quality.The simulation results of point target and sound absorption spot in the mode of full receiver and synthetic aperture show that the proposed algorithm can improve the resolution of 6 dB about twice on the basis of minimum variance, and in synthetic aperture mode, the resolution of the proposed algorithm is about twice as high as that in the mode of synthetic aperture.The contrast is improved by 8 dB on the basis of the least variance algorithm in feature space, and it is much better than the traditional delay superposition algorithm.Finally, experiments show that the improved minimum variance algorithm is better in resolution, contrast and robustness to noise, which can effectively improve the quality of ultrasonic images.
【作者单位】：重庆大学输配电装备及系统安全与新技术国家重点实验室;
【基金】：国家自然科学基金项目(51677010)资助
【分类号】：TB559

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