Strong-robustness minimum-variance ultrasonic beam forming method based on subspace oblique projection

A minimum variance, subspace technology, applied in the re-radiation of sound waves, radio wave measurement systems, instruments, etc., can solve the problems of poor robustness of the feature space minimum variance algorithm, suppression of useful signals, image distortion, etc. Robustness, reduction of variance in background regions, effect of guaranteed contrast and resolution

CN114415187APending Publication Date: 2022-04-29CHONGQING UNIV +3
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2022-04-29

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Abstract

The invention relates to a strong-robustness minimum-variance ultrasonic beam forming method based on subspace oblique projection, and belongs to the technical field of ultrasonic imaging. The method comprises the following steps: performing spatial smoothing and diagonal loading processing on echo signals received by an ultrasonic array to obtain a sample covariance matrix, decomposing the characteristics of the sample covariance matrix into a signal subspace and an interference noise subspace, and constructing a transition matrix according to characteristic vectors of the signal subspace and corresponding characteristic values; calculating an oblique projection operator in combination with the expected direction vector and a pseudo-inverse matrix of the transition matrix, and projecting a weight obtained by minimum variance beam forming into a signal subspace in which the expected direction vector is located along a direction parallel to the interference noise direction matrix by using the oblique projection operator to obtain a new weight; performing weighted summation on the ultrasonic array echo signals by using the new weight to obtain a final adaptive beam forming signal; according to the method, the algorithm robustness can be remarkably enhanced, the image resolution is maintained, background noise is suppressed, and the ultrasonic imaging quality is improved on the whole.
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Description

technical field

[0001] The invention belongs to the technical field of ultrasonic imaging, and relates to a strong robustness minimum variance ultrasonic beam forming method based on subspace oblique projection. Background technique

[0002] Ultrasound imaging is widely used in various detection fields due to its advantages of non-invasiveness, safety, convenience and low cost. The core content of ultrasonic imaging is the beamforming technology. The most widely used beamforming technology is the Delay And Sum algorithm (DAS), which delays the received echo signal according to the geometric position relationship of the array element channel. When , the data is aligned and superimposed. The traditional DAS algorithm is simple in principle and fast in imaging speed, but due to the weighting of the fixed window function, the width of the main lobe increases, the resolution is low, and the imaging quality is poor.

[0003] The Minimum Variance (MV) adaptive beamforming algorit...

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Embodiment Construction

[0051] Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes, and various modifications or changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the diagrams provided in the following embodiments are only schematically illustrating the basic concept of the present invention, and the following embodiments and the features in the embodiments can be combined with each other in the case of no conflict.

[0052] see Figure 1 ~ Figure 4 , figure 1 Be the algorithm flowchart of the present invention, as figure 1 As shown, the present invention has designed a ...