Characteristic space-based backward and forward adaptive wave beam forming method

Abstract

The invention discloses a characteristic space-based backward and forward adaptive wave beam forming method, and relates to the technical field of medical ultrasonic imaging. The method comprises the following steps of: performing focusing delay processing and backward and forward smoothing on a plurality of paths of sampled signals of a received array to obtain a sample covariance matrix estimate; performing diagonal loading on the sample covariance matrix estimate and then combining with a direction vector to calculate an adaptive wave beam forming weight; performing characteristic decomposition on the backward and forward covariance matrix estimate after the diagonal loading to construct a signal subspace; projecting the adaptive wave beam forming weight into the signal subspace to obtain a new adaptive wave beam forming weight; and finally, performing weighted summation on a plurality of paths of data subjected to the backward and forward smoothing by the new adaptive wave beam forming weight so as to obtain a path of adaptive wave beam signal. By using the method, the problems of improving the image resolution and contrast, being sensitive to the direction error and the like existing in the conventional adaptive wave beam forming algorithm are solved, and the overall quality of the ultrasonic imaging is comprehensively improved.

Description

technical field [0001] The invention belongs to the technical field of ultrasonic imaging, and in particular relates to a feature space-based forward-backward self-adaptive beamforming method. Background technique [0002] In medical ultrasound imaging, echo signals from non-source directions introduce extensive image clutter, resulting in image degradation. At present, the traditional delay and superposition method (DAS) is generally used to reduce the interference of signals in the non-source direction and improve the signal strength in the source direction. This method applies different delays to the data received by different channels, and then adds them together to obtain the amplitude of the desired focus point. The DAS algorithm is simple and easy to implement, but its spatial resolution is low, the imaging contrast is poor, and it is sensitive to direction vector errors. In order to reduce the impact of sidelobe signals on imaging contrast, people usually use ampli...

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Problems solved by technology

[0005] In view of this, in order to solve the above problems, the present invention proposes a method that can simultaneously improve the image contrast, resolution and the robustness of the beamforming algorithm, solve the problem of being sensitive to direction errors, and effectively overcome the robustness of the traditional adaptive beamforming algorithm. Low performance, can not significantly improve the image contrast and other issues, and comprehensively improve the overall quality of ultrasound images

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