阅读说明：本技术 超声成像降噪方法及超声成像设备 (Ultrasonic imaging noise reduction method and ultrasonic imaging equipment ) 是由 郭威 吴方刚 刘峻杉 于 2021-08-23 设计创作，主要内容包括：本发明揭示了一种超声成像降噪方法及超声成像设备,降噪方法包括：判断所述超声成像设备符合预设前置条件时,输出实验波束触发信号,控制至少两个处于不同横向位置的超声单元分别发出实验波束执行空扫描；提取表征同一横向位置,且与所述实验波束对应的至少两组标定波束,分析所述标定波束分别在预设深度的探测数据,对应得到至少两组采样数据；根据预设离散关系式和所述采样数据计算得到标准噪声数据；利用所述标准噪声数据对超声成像过程执行降噪。本发明提供的超声成像降噪方法具有降噪速度快,自适应程度高的技术效果,同时算法过程更为简洁,充分利用了形成后波束的特点,应用于并行接收波束形成的超声成像中,降噪效果更为显著。(The invention discloses an ultrasonic imaging noise reduction method and ultrasonic imaging equipment, wherein the noise reduction method comprises the following steps: when the ultrasonic imaging equipment is judged to accord with the preset precondition, an experiment beam trigger signal is output, and at least two ultrasonic units in different transverse positions are controlled to respectively send out experiment beams to execute null scanning; extracting at least two groups of calibration wave beams representing the same transverse position and corresponding to the experimental wave beams, analyzing detection data of the calibration wave beams at preset depths respectively, and correspondingly obtaining at least two groups of sampling data; calculating to obtain standard noise data according to a preset discrete relation and the sampling data; performing noise reduction on the ultrasound imaging procedure using the standard noise data. The ultrasonic imaging noise reduction method provided by the invention has the technical effects of high noise reduction speed and high self-adaption degree, meanwhile, the algorithm process is simpler, the characteristic of formed beams is fully utilized, and the noise reduction effect is more obvious when the method is applied to ultrasonic imaging formed by parallel receiving beams.)

1. An ultrasonic imaging noise reduction method is applied to an ultrasonic imaging device and is characterized by comprising the following steps:

when the ultrasonic imaging equipment is judged to accord with the preset precondition, an experiment beam trigger signal is output, and at least two ultrasonic units in different transverse positions are controlled to respectively send out experiment beams to execute null scanning;

extracting at least two groups of calibration wave beams representing the same transverse position and corresponding to the experimental wave beams, analyzing detection data of the calibration wave beams at preset depths respectively, and correspondingly obtaining at least two groups of sampling data;

calculating to obtain standard noise data according to a preset discrete relation and the sampling data;

performing noise reduction on the ultrasound imaging procedure using the standard noise data.

2. The ultrasound imaging noise reduction method according to claim 1, wherein the method specifically comprises:

outputting a preposed detection signal, controlling the ultrasonic unit to execute near field scanning, and correspondingly acquiring near field image information;

and performing peak value detection on the near field image information, and if the near field image information comprises at least two groups of peak values exceeding a preset threshold value and the occurrence of the at least two groups of peak values shows a periodic rule, outputting the experimental wave beam trigger signal.

3. The ultrasound imaging noise reduction method according to claim 1, wherein the method specifically comprises:

outputting a preposed detection signal, controlling the ultrasonic unit to execute near field scanning, and correspondingly acquiring near field beam information;

and performing peak detection on the near field beam information, and if the near field beam information comprises at least two groups of amplitudes exceeding a preset threshold and the occurrence of the at least two groups of amplitudes shows a periodic rule, outputting the experimental beam trigger signal.

4. The ultrasound imaging noise reduction method according to claim 1, further comprising:

searching preset apodization coefficients corresponding to the calibration wave beams respectively;

respectively executing amplitude compensation on the sampling data by taking the apodization coefficients as weights to obtain compensation data; wherein the apodization coefficient is used for characterizing the relative position difference of the calibration beam and the experiment beam;

and calculating to obtain standard noise data according to a preset discrete relation and the compensation data.

5. The ultrasound imaging noise reduction method according to claim 4, wherein the method specifically comprises:

respectively calculating absolute values of the compensation data to obtain at least two absolute noise data;

and screening to obtain the maximum value in the absolute noise data, and taking the maximum value as the standard noise data.

6. The ultrasound imaging noise reduction method according to claim 4, wherein the method specifically comprises:

respectively calculating absolute values of the compensation data to obtain at least two absolute noise data;

and calculating the standard deviation of the absolute noise data, and taking the standard deviation as the standard noise data.

7. The ultrasound imaging noise reduction method according to claim 4, wherein the method specifically comprises:

setting an apodization reference function with a preset length;

calculating a plurality of apodization coefficients according to the apodization reference function and the relative position difference between the ultrasonic units; wherein the apodization reference function is one or more of a rectangular window, a Hamming window function, and a Hainin window function.

8. The ultrasound imaging noise reduction method according to claim 1, wherein the method specifically comprises:

outputting a detection beam trigger signal, and controlling a plurality of ultrasonic units to send out detection beams;

receiving a plurality of echo signals respectively corresponding to the detection beams, performing beam forming on the echo signals, and respectively corresponding to a plurality of receiving beams;

respectively subtracting the standard noise data from the plurality of received beams to correspondingly obtain a plurality of noise reduction beams;

and respectively carrying out scale amplification on the noise reduction wave beams, and carrying out ultrasonic imaging by using the amplified noise reduction wave beams.

9. The ultrasound imaging noise reduction method according to claim 1, wherein the method specifically comprises:

outputting a detection beam trigger signal, and controlling a plurality of ultrasonic units to send out detection beams;

receiving a plurality of echo signals respectively corresponding to the detection beams, performing beam forming on the echo signals, and respectively corresponding to a plurality of receiving beams;

respectively carrying out logarithmic compression on the receiving wave beams and the standard noise data, and carrying out subtraction operation on the compressed receiving wave beams and the standard noise data to correspondingly obtain a plurality of noise reduction wave beams;

and respectively carrying out scale amplification on the noise reduction wave beams, and carrying out ultrasonic imaging by using the amplified noise reduction wave beams.

10. An ultrasonic imaging device is characterized by comprising a control module and a plurality of ultrasonic units, wherein the ultrasonic units are configured to be arranged in an array; the ultrasonic imaging device is configured to carry out noise reduction by the ultrasonic imaging noise reduction method according to any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of ultrasonic imaging, in particular to an ultrasonic imaging noise reduction method and ultrasonic imaging equipment.

Background

Parameters such as an imaging focus, an imaging depth, a gain, a dynamic range and the like are often required to be manually adjusted in the ultrasonic imaging to improve the image quality, and compared with other imaging modalities, noise in the ultrasonic imaging is a main problem causing poor image quality. In the existing ultrasonic imaging equipment, structures such as knobs are often configured, an operator needs to manually adjust related parameters of ultrasonic imaging according to problems appearing in a picture, and then influences of noise on the image are reduced, but the adjustment mode excessively depends on experience of the operator, self-adaption is difficult to realize in the face of different operating environments, and meanwhile, the defect that the adjustment process is long is overcome, and user experience is poor.

Disclosure of Invention

One of the objectives of the present invention is to provide an ultrasound imaging noise reduction method, so as to solve the technical problems in the prior art that the quality of an ultrasound imaging image is poor, the noise reduction process is long, and self-adaptation cannot be realized.

An object of the present invention is to provide an ultrasonic imaging apparatus.

In order to achieve one of the above objects, an embodiment of the present invention provides an ultrasound imaging noise reduction method, applied in an ultrasound imaging apparatus, including: when the ultrasonic imaging equipment is judged to accord with the preset precondition, an experiment beam trigger signal is output, and at least two ultrasonic units in different transverse positions are controlled to respectively send out experiment beams to execute null scanning; extracting at least two groups of calibration wave beams representing the same transverse position and corresponding to the experimental wave beams, analyzing detection data of the calibration wave beams at preset depths respectively, and correspondingly obtaining at least two groups of sampling data; calculating to obtain standard noise data according to a preset discrete relation and the sampling data; performing noise reduction on the ultrasound imaging procedure using the standard noise data.

As a further improvement of an embodiment of the present invention, the method specifically includes: outputting a preposed detection signal, controlling the ultrasonic unit to execute near field scanning, and correspondingly acquiring near field image information; and performing peak value detection on the near field image information, and if the near field image information comprises at least two groups of peak values exceeding a preset threshold value and the occurrence of the at least two groups of peak values shows a periodic rule, outputting the experimental wave beam trigger signal.

As a further improvement of an embodiment of the present invention, the method specifically includes: outputting a preposed detection signal, controlling the ultrasonic unit to execute near field scanning, and correspondingly acquiring near field beam information; and performing peak detection on the near field beam information, and if the near field beam information comprises at least two groups of amplitudes exceeding a preset threshold and the occurrence of the at least two groups of amplitudes shows a periodic rule, outputting the experimental beam trigger signal.

As a further improvement of an embodiment of the present invention, the method further comprises: searching preset apodization coefficients corresponding to the calibration wave beams respectively; respectively executing amplitude compensation on the sampling data by taking the apodization coefficients as weights to obtain compensation data; wherein the apodization coefficient is used for characterizing the relative position difference of the calibration beam and the experiment beam; and calculating to obtain standard noise data according to a preset discrete relation and the compensation data.

As a further improvement of an embodiment of the present invention, the method specifically includes: respectively calculating absolute values of the compensation data to obtain at least two absolute noise data; and screening to obtain the maximum value in the absolute noise data, and taking the maximum value as the standard noise data.

As a further improvement of an embodiment of the present invention, the method specifically includes: respectively calculating absolute values of the compensation data to obtain at least two absolute noise data; and calculating the standard deviation of the absolute noise data, and taking the standard deviation as the standard noise data.

As a further improvement of an embodiment of the present invention, the method specifically includes: setting an apodization reference function with a preset length; calculating a plurality of apodization coefficients according to the apodization reference function and the relative position difference between the ultrasonic units; wherein the apodization reference function is one or more of a rectangular window, a Hamming window function, and a Hainin window function.

As a further improvement of an embodiment of the present invention, the method specifically includes: outputting a detection beam trigger signal, and controlling a plurality of ultrasonic units to send out detection beams; receiving a plurality of echo signals respectively corresponding to the detection beams, performing beam forming on the echo signals, and respectively corresponding to a plurality of receiving beams; respectively subtracting the standard noise data from the plurality of received beams to correspondingly obtain a plurality of noise reduction beams; and respectively carrying out scale amplification on the noise reduction wave beams, and carrying out ultrasonic imaging by using the amplified noise reduction wave beams.

As a further improvement of an embodiment of the present invention, the method specifically includes: outputting a detection beam trigger signal, and controlling a plurality of ultrasonic units to send out detection beams; receiving a plurality of echo signals respectively corresponding to the detection beams, performing beam forming on the echo signals, and respectively corresponding to a plurality of receiving beams; respectively carrying out logarithmic compression on the receiving wave beams and the standard noise data, and carrying out subtraction operation on the compressed receiving wave beams and the standard noise data to correspondingly obtain a plurality of noise reduction wave beams; and respectively carrying out scale amplification on the noise reduction wave beams, and carrying out ultrasonic imaging by using the amplified noise reduction wave beams.

In order to achieve one of the above objects, an embodiment of the present invention provides an ultrasound imaging apparatus, including a control module and a plurality of ultrasound units, wherein the ultrasound units are configured in an array arrangement; the ultrasonic imaging device is configured to carry the ultrasonic imaging noise reduction method of any one of the above technical solutions to reduce noise.

Compared with the prior art, the ultrasonic imaging noise reduction method provided by the invention has the technical effects that after the experimental wave beam is output by executing the empty scanning, at least two groups of calibration wave beams representing the same position are extracted, special data extraction and processing are carried out on the calibration wave beams, and the noise reduction processing is executed on the ultrasonic imaging process by taking the obtained standard noise data as the global noise threshold, so that the noise reduction speed is high, and the self-adaptive degree is high; compared with the prior art of simply utilizing noise data in a frame detected by empty scanning to perform noise reduction, the method has the advantages that the algorithm process is simpler, the characteristics of formed beams are fully utilized, and the method is applied to ultrasonic imaging formed by parallel receiving beams, and the noise reduction effect is more obvious.

Drawings

FIG. 1 is a schematic diagram of an ultrasound imaging apparatus in an embodiment of the present invention;

FIG. 2 is a schematic diagram of the steps of a noise reduction method for ultrasonic imaging according to an embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating the steps of a first embodiment of a noise reduction method for ultrasound imaging according to an embodiment of the present invention;

FIG. 4 is a schematic diagram illustrating the steps of a second embodiment of a noise reduction method for ultrasound imaging according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of the steps of a noise reduction method for ultrasound imaging in another embodiment of the present invention;

FIG. 6 is a schematic diagram illustrating the steps of a first embodiment of a noise reduction method for ultrasound imaging in accordance with another embodiment of the present invention;

FIG. 7 is a schematic diagram of the steps of a second embodiment of a noise reduction method for ultrasound imaging in another embodiment of the present invention;

FIG. 8 is a schematic diagram illustrating steps of apodization parameter presetting in an ultrasonic imaging noise reduction method according to an embodiment of the present invention;

FIG. 9 is a schematic diagram illustrating the steps of a first embodiment of a noise reduction method for ultrasound imaging according to yet another embodiment of the present invention;

fig. 10 is a schematic diagram of the steps of a second embodiment of the noise reduction method for ultrasonic imaging according to still another embodiment of the present invention.

Detailed Description

The present invention will be described in detail below with reference to specific embodiments shown in the drawings. These embodiments are not intended to limit the present invention, and structural, methodological, or functional changes made by those skilled in the art according to these embodiments are included in the scope of the present invention.

It is to be noted that the term "comprises," "comprising," or any other variation thereof is intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the scheme of imaging by using ultrasound, if a detected image with high quality is desired, a series of parameters such as an imaging focus, an imaging depth, a gain, a dynamic range and the like are generally required to be considered comprehensively, and meanwhile, due to the limitation of a detection environment, ultrasound imaging is often accompanied by a large noise problem, and besides inherent speckle noise, thermal noise, electromagnetic noise, quantization noise and the like are also included in calculation in the processes of sampling and analog-to-digital conversion, so that the image quality is influenced.

In the technical scheme of beam forming, in particular parallel receive beam forming, in which after an ultrasonic probe receives an echo signal, an ultrasonic beam with directivity at a spatial position is reconstructed by using a time correspondence relationship, a plurality of overlapped or non-overlapped ultrasonic beams are correspondingly reconstructed in a transmission coverage area after one-time focused ultrasonic transmission, and an image is generated, a transmission and reception process, a process of reconstructing (or forming) a beam, and a process of finally generating an image are often affected by noise in a layer-by-layer manner to reduce image quality. Therefore, on the premise of reducing the influence of noise, the ultrasonic imaging, especially the ultrasonic imaging implementing the parallel receive beam forming scheme, is a problem to be solved urgently, and is also the purpose of the technical scheme provided by the invention.

An embodiment of the present invention provides an ultrasound imaging apparatus, as shown in fig. 1, including a main control module 11 and a plurality of ultrasound units, where the main control module 11 is connected to the ultrasound units to control the ultrasound units to transmit and receive ultrasound signals, and further the main control module 11 collects and receives the received signals to process the signals to generate ultrasound images. The transmission mode of the ultrasonic signal may adopt plane wave imaging, that is, the main control module 11 may be configured to control all the ultrasonic units to transmit synchronously, so as to generate a planar transmission wave front; of course, the transmission mode may also adopt synthetic aperture imaging, that is, the main control module 11 is configured to control a single or a small number of ultrasound units to transmit in sequence, and the transmission mode of the ultrasound signals is not limited in the present invention.

In this embodiment, the ultrasound units are configured to be arranged in an array to form the ultrasound unit array 12, so as to generate the transmitted wavefront, specifically, 64, 96, 128, 192, 256 or other number of ultrasound units may be configured in the ultrasound unit array, a single ultrasound unit may have a function of transceiving ultrasound waves at the same time, or may be partially used to transmit ultrasound waves and partially used to receive echoes, that is, as shown in fig. 1, the ultrasound unit array 12 is configured to include an ultrasound transmitting unit 121 and an ultrasound receiving unit 122. Of course, the present invention is not limited to the above-described configuration.

Further, in order to realize high-quality imaging and reduce interference of noise on image quality, the ultrasound imaging apparatus provided by the present invention further includes a beam forming module 13, a data processing module 14 and an image processing module 15, which are respectively connected to the main control module 11.

The main control module 11 is further configured to output an experimental beam and/or a probe beam trigger signal, control the ultrasound unit array 12 to emit a corresponding beam, and correspondingly receive an echo signal, specifically, the experimental beam is defined as a beam controlled and transmitted in a noise data calculation process in this embodiment, and the probe beam is defined as a beam controlled and transmitted in an actual ultrasound imaging process in this embodiment;

the beam forming module 13 is configured to receive an echo signal and perform beam forming, so as to obtain a plurality of calibration beams and/or reception beams, specifically, the calibration beams are defined as beams received and analyzed in a noise data calculation process in this embodiment, and the reception beams are defined as beams received and analyzed in an actual ultrasound imaging process in this embodiment;

the data processing module 14 is configured to obtain standard noise data through calculation according to the calibration beam, store the standard noise data, and discrete relational correlation data required for calculating the standard noise data, and perform noise reduction calculation on the received beam by using the standard noise data, specifically, the calculation process of the standard noise data is an ultrasound imaging noise reduction method stored inside the data processing module 14, the storage of the correlation data may be implemented by the data processing module 14, or may be separately provided with a calculation unit, a storage unit, and the like, which is not limited in the present invention;

the image processing module 15 is configured to perform ultrasonic imaging and output according to the denoised beam data or necessary data with other forms or contents, and specifically, the ultrasonic imaging may be transmitted to an upper computer or other terminal devices, or may be directly displayed through a display screen;

although the above modules are shown and described separately in fig. 1 and in the text, it is not intended that the present invention be limited to a split modular design and any resulting integration or further subdivision is within the scope of the present invention. Meanwhile, in the embodiment, the main control module 11 is connected with each functional module to realize detection, calculation and imaging, but in other embodiments of the present invention, other wiring methods can be adopted to realize the technical effects.

Further, the ultrasound imaging apparatus further includes a precondition determining module 16 connected to the main control module 11, and configured to determine whether the ultrasound imaging apparatus meets a preset starting condition of the noise calculating process and/or a starting condition of the detection imaging process. In the present embodiment, the starting condition of the noise calculation process is configured to detect that the ultrasound imaging apparatus is at least partially coated with the coupling agent and in a null scan state; the starting condition of the detection imaging process is configured to detect an imaging target (or object to be detected). Of course, the above-mentioned starting conditions are not necessarily required as technical features for implementing the present invention, and in the present embodiment, only the starting conditions of the noise calculation process are preset and determined.

The process of performing the determination is specifically configured in this embodiment, the main control module 11 outputs a pre-detection signal to the ultrasound unit array 12 and receives the relevant data, the data is received by the pre-condition determination module 16 for analysis and determination, and the main control module 11 selectively outputs the experiment beam trigger signal and/or the detection beam trigger signal after receiving the determination result.

To further achieve the technical effects expected by the present invention, in one embodiment of the present invention, there is provided an ultrasound imaging noise reduction method, as shown in fig. 2, including:

step 21, when the ultrasonic imaging device is judged to meet the preset precondition, outputting an experiment beam trigger signal, and controlling at least two ultrasonic units at different transverse positions to respectively send out experiment beams to execute null scanning;

step 22, extracting at least two groups of calibration beams representing the same transverse position and corresponding to the experimental beams, analyzing the detection data of the calibration beams at the preset depth respectively, and correspondingly obtaining at least two groups of sampling data;

step 23, calculating to obtain standard noise data according to a preset discrete relation and the sampling data;

and 24, denoising the ultrasonic imaging process by using the standard noise data.

The principle of parallel receiving beam imaging is that the ultrasonic units at different transverse positions are controlled to emit beams simultaneously or sequentially, beam forming is performed corresponding to received echo signals, a plurality of beams received at a certain transverse position are compounded to form a beam finally used for imaging, and a plurality of imaging beams corresponding to a plurality of transverse positions are processed to form a frame of ultrasonic image.

In the null scanning state, because there is no influence of an imaging target, a received echo signal may be determined to only include background noise, because the data distribution of the background noise at different lateral positions is relatively average, discrete background noise data is difficult to calculate to obtain data that can summarize the overall environmental noise condition, and if a beam corresponding to all the received echo data in the ultrasound unit array 12 is calculated to obtain noise data, it is necessary to extend the time for null scanning and noise reduction data calculation, therefore, in this embodiment, by controlling at least two ultrasound units arranged at different lateral positions to emit experimental beams, at least two sets of calibration beams received at the same position are correspondingly extracted and analyzed, and efficiency can be greatly improved, although the present invention is not limited to this embodiment, in other embodiments, the main control module 11 is configured to control four ultrasound units arranged at different lateral positions to emit experimental beams, and correspondingly receiving four groups of calibration beams for analysis. In other embodiments, the standard noise data may be obtained by performing a weighting operation on noise data obtained at different positions.

Further, in this embodiment, the transverse direction is defined as any direction on the plane of the array of ultrasound elements 12, and the depth defines a direction perpendicular to the plane of the array of ultrasound elements 12, along which the ultrasound elements perform transmission, although in other embodiments the definition of depth and/or the ultrasound element transmission direction may be arranged at an angle to the plane.

In the case that the ultrasound imaging apparatus is coated with the coupling agent, the acquired echo signals cannot represent a noise environment due to multiple reflections occurring between the coupling agent and the ultrasound unit array 12 (or referred to as the ultrasound probe surface), so the preset depth in step 22 is defined as a far field in the present embodiment, i.e., a region below 1/3 in the scanned region, and thus more accurate standard noise data can be calculated.

The sampling data is used as a plurality of noise data of different transmitting positions at the same receiving position, standard noise data which is enough to summarize the current noise situation can be obtained by utilizing the corresponding weighting relation, and the standard noise data is continuously utilized to carry out noise reduction on the subsequent imaging process, particularly the process of processing a receiving beam and a composite imaging beam.

In the present invention, the above step 21 is refined to generate two examples of the present embodiment as shown in fig. 3 and 4, wherein the first example of the present embodiment is shown in fig. 3, and the second example is shown in fig. 4.

Specifically, the method for noise reduction in ultrasonic imaging provided by the first embodiment includes:

step 211, outputting a pre-detection signal, controlling the ultrasonic unit to execute near field scanning, and correspondingly acquiring near field image information;

step 212, performing peak detection on the near-field image information, and if the near-field image information includes at least two groups of peak values exceeding a preset threshold value and the at least two groups of peak values appear to present a periodic rule, outputting an experiment beam trigger signal to control at least two ultrasonic units at different transverse positions to respectively send out experiment beams to perform null scanning;

step 22, extracting at least two groups of calibration beams representing the same transverse position and corresponding to the experimental beams, analyzing the detection data of the calibration beams at the preset depth respectively, and correspondingly obtaining at least two groups of sampling data;

step 23, calculating to obtain standard noise data according to a preset discrete relation and the sampling data;

and 24, denoising the ultrasonic imaging process by using the standard noise data.

After the couplant is coated on the surface of the ultrasonic unit array 12, the received echo signals generate large numerical fluctuation in the near-field region, a plurality of high-echo transverse stripes appear in the near-field region in an image, and at least two groups of wave peaks with peak values exceeding a preset threshold value continuously appear in near-field image information after the high-echo transverse stripes are reflected, so that whether the couplant is coated is determined by comparing the numerical relationship between the peak values and the preset threshold value and detecting whether the wave peaks appear periodically, and whether an experimental wave beam trigger signal is output is determined according to a couplant coating judgment signal.

For the above judgment that the periodicity regularity is present, defining that the at least two groups of peak values include a first peak value and a second peak value, then: calculating a first depth difference between the first peak and the array of ultrasound units, and a second depth difference between the second peak and the first peak; the first depth difference and the second depth difference are subjected to difference to obtain a relative difference value; and comparing the relation between the relative difference value and a preset maximum error, if the relative difference value is greater than the maximum error, judging that the occurrence of the peak value does not show a periodic rule, and if the relative difference value is less than or equal to the maximum error, judging that the occurrence of the peak value shows the periodic rule. That is, preferably, the occurrence positions of the at least two sets of peaks are equally spaced.

Of course, according to different working conditions, the following judgment modes can be provided, namely: calculating a first depth difference between the first peak and the array of ultrasound units, and a second depth difference between the second peak and the first peak; the first depth difference and the second depth difference are subjected to quotient obtaining relative multiple; and comparing the relation between the relative multiple and a preset standard multiple, if the relative multiple is not equal to the standard multiple, judging that the occurrence of the peak value does not show a periodic rule, and if the relative multiple is not equal to the standard multiple, judging that the occurrence of the peak value shows the periodic rule.

The maximum error represents a maximum error value allowed in the process of judging whether the couplant is smeared or not, the maximum error can be preset to realize a global automation effect, and the maximum error is adjusted according to the requirement of an operator or the property of the couplant, so that the method is not limited herein. The standard multiple may be a fixed value in an actual working condition, or may change linearly or nonlinearly according to a change in a distance between the peak and the ultrasound unit array, and an operator may adjust and preset the standard multiple as needed.

A second embodiment of the present embodiment provides an ultrasound imaging noise reduction method, including:

step 211', outputting a pre-detection signal, controlling the ultrasonic unit to perform near field scanning, and correspondingly acquiring near field beam information;

step 212', performing peak detection on the near field beam information, and if the near field beam information includes at least two groups of amplitudes exceeding a preset threshold and the at least two groups of amplitudes appear to present a periodic rule, outputting an experimental beam trigger signal to control at least two ultrasonic units in different transverse positions to respectively send out an experimental beam to perform null scanning;

step 22, extracting at least two groups of calibration beams representing the same transverse position and corresponding to the experimental beams, analyzing the detection data of the calibration beams at the preset depth respectively, and correspondingly obtaining at least two groups of sampling data;

step 23, calculating to obtain standard noise data according to a preset discrete relation and the sampling data;

and 24, denoising the ultrasonic imaging process by using the standard noise data.

In addition to the detection by the near-field image information in the first embodiment, whether the couplant is applied or not can also be determined by comparing the near-field beam information and the far-field beam information, specifically, comparing the strength of the near-field beam information and the far-field beam information. It should be noted that the intensity waveform of the near field image information is always positive, and the intensity waveform of the near field beam information is positive and negative values fluctuating within a certain range, so the amplitude of the positive and negative values is compared with a preset threshold value in the present embodiment. In addition, the process of determining whether the occurrence of the amplitude exhibits the periodic regularity may be specially configured according to the needs of the operator, or the scheme of determining whether the occurrence of the peak exhibits the periodic regularity may be alternatively implemented.

The preset threshold value may be set to a gray level of 100 (a gray level range of 0 to 255) in the present embodiment. For the method for further determining the empty-scanning state, the present embodiment is configured to determine that the empty-scanning state is currently set, that is, the ultrasound imaging apparatus has no imaging target, when the amplitude does not exceed a preset threshold continuously for a preset time period, where the preset time period is preferably 0.1s, and the preset threshold is set to be a gray level of 100 (gray level range of 0-255), by detecting the amplitude of the echo signal. Of course, the judgment of the empty scan and the judgment method of the couplant application are only used as reference, and a person skilled in the art can alternatively adopt a method capable of achieving the same technical effect.

In order to further improve the accuracy of the standard noise data, the present invention provides another embodiment, as shown in fig. 5 to 7.

As shown in fig. 5, in this embodiment, the method for noise reduction in ultrasonic imaging specifically includes:

step 21, when the ultrasonic imaging device is judged to meet the preset precondition, outputting an experiment beam trigger signal, and controlling at least two ultrasonic units at different transverse positions to respectively send out experiment beams to execute null scanning;

step 22, extracting at least two groups of calibration beams representing the same transverse position and corresponding to the experimental beams, analyzing the detection data of the calibration beams at the preset depth respectively, and correspondingly obtaining at least two groups of sampling data;

231, searching preset apodization coefficients corresponding to the calibration beams respectively;

step 232, using the apodization coefficient as weight, respectively executing amplitude compensation to the sampling data to obtain compensation data;

step 233, calculating to obtain standard noise data according to a preset discrete relation and the compensation data;

and 24, denoising the ultrasonic imaging process by using the standard noise data.

The ultrasonic units with the calibrated beams corresponding to different transverse positions form a sound field in an imaging process, the sound field comprises a main lobe determining the resolution of an image and a side lobe generating an artifact, and the existence of the side lobe can reduce the signal-to-noise ratio of the image to cause the low resolution of the image. Additionally, in the present embodiment, the apodization coefficients are used to characterize the relative position difference of the calibration beam and the experimental beam.

Specifically, in the present embodiment, the amplitude of the sampled data is compensated by the apodization coefficient using the correspondence relationship between "ultrasound unit-apodization coefficient-calibration beam-sampled data", and further, the standard noise data is obtained by calculating using the discrete relation and the compensated data. The numerical value of the apodization coefficient needs to be calculated or selected according to the relative position relationship in the transverse direction of the ultrasonic unit, and the ultrasonic units in different transverse positions are not limited to have different apodization coefficients. Further, preferably, the amplitude compensation is configured to multiply the sampled data by the corresponding apodization coefficient to calculate the resultant product as the compensation data.

This embodiment further provides two embodiments, a first embodiment as shown in fig. 6 and a second embodiment as shown in fig. 7. Wherein, the first embodiment specifically includes:

step 21, when the ultrasonic imaging device is judged to meet the preset precondition, outputting an experiment beam trigger signal, and controlling at least two ultrasonic units at different transverse positions to respectively send out experiment beams to execute null scanning;

step 22, extracting at least two groups of calibration beams representing the same transverse position and corresponding to the experimental beams, analyzing the detection data of the calibration beams at the preset depth respectively, and correspondingly obtaining at least two groups of sampling data;

231, searching preset apodization coefficients corresponding to the calibration beams respectively;

step 232, using the apodization coefficient as weight, respectively executing amplitude compensation to the sampling data to obtain compensation data;

step 2331, calculating absolute values of the compensation data respectively to obtain at least two absolute noise data;

step 2332, screening to obtain the maximum value in the absolute noise data, and taking the maximum value as standard noise data;

and 24, denoising the ultrasonic imaging process by using the standard noise data.

Because no imaging target exists in the empty scanning state, the value of the echo signal generated in the ideal state is 0, so that the sampling data obtained in the empty scanning state is actually a positive value and a negative value which float between more than 0 and less than 0, the absolute values of the positive value and the negative value are taken and screened to obtain a maximum value, and the maximum value is taken as standard noise data to achieve a stronger noise reduction effect. The standard noise data obtained by performing the above embodiment is represented as:

Cutoff₁＝max(abs(a₁s₁,a₂s₂,a₂s₃,a₁s₄))；

wherein, Cutoff₁Is to carry out the above-mentioned first embodimentThe standard noise data obtained by the example, max () is the function for finding the maximum value, abs () is the function for finding the absolute value, s₁、s₂、s₃、s₄Sampled data corresponding to four sets of calibration beams, a₁Is s is₁And s₄The apodization coefficient (or weight), a₂Is s is₂And s₃The apodization coefficient of (2). Therefore, the apodization coefficients corresponding to the ultrasonic units at different positions can be the same.

A second embodiment of the present embodiment provides an ultrasound imaging noise reduction method, which specifically includes:

step 21, when the ultrasonic imaging device is judged to meet the preset precondition, outputting an experiment beam trigger signal, and controlling at least two ultrasonic units at different transverse positions to respectively send out experiment beams to execute null scanning;

step 22, extracting at least two groups of calibration beams representing the same transverse position and corresponding to the experimental beams, analyzing the detection data of the calibration beams at the preset depth respectively, and correspondingly obtaining at least two groups of sampling data;

231, searching preset apodization coefficients corresponding to the calibration beams respectively;

step 232, using the apodization coefficient as weight, respectively executing amplitude compensation to the sampling data to obtain compensation data;

step 2331, calculating absolute values of the compensation data respectively to obtain at least two absolute noise data;

step 2332' of calculating the standard deviation of the absolute noise data and taking the standard deviation as standard noise data;

and 24, denoising the ultrasonic imaging process by using the standard noise data.

The standard deviation reflects the degree of dispersion of the plurality of absolute noise data, and more accurate standard noise data can be calculated. The standard noise data obtained by performing the above embodiment is represented as:

Cutoff₂＝std(abs(a₁s₁,a₂s₂,a₂s₃,a₁s₄))；

wherein, Cutoff₂Is the standard noise data obtained by performing the second embodiment described above, std () is a function for calculating the standard deviation, abs () is a function for calculating the absolute value, s₁、s₂、s₃、s₄Sampled data corresponding to four sets of calibration beams, a₁Is s is₁And s₄The apodization coefficient (or weight), a₂Is s is₂And s₃The apodization coefficient of (2).

For the above procedure of presetting the apodization function, there is further provided in this embodiment a method, as shown in fig. 8, including:

step 31, setting an apodization reference function with a preset length;

and step 32, calculating a plurality of apodization coefficients according to the apodization reference function and the relative position difference between the ultrasonic units.

The apodization reference function is used as a step length for measuring the lateral position relationship between the ultrasound units, and in the present embodiment, the function for characterizing the position difference between the experimental beam and the calibration beam may be configured as one or more of a rectangular window, a Hamming window function (Hamming), and a Hanning window function (Hanning), but in other embodiments, a person skilled in the art may select other window functions, or select other criteria according to physical principles, and the apodization coefficients may also be formed. Meanwhile, the specific sequence positions of step 31 and step 32 in this embodiment may be adjusted according to the needs of those skilled in the art, and any position before step 231 can achieve the technical effect expected by the present invention.

Fig. 9 and 10 provide two examples of the noise reduction method for ultrasonic imaging in still another embodiment of the present invention, and specifically, fig. 9 shows a first example in this embodiment, which includes:

step 21, when the ultrasonic imaging device is judged to meet the preset precondition, outputting an experiment beam trigger signal, and controlling at least two ultrasonic units at different transverse positions to respectively send out experiment beams to execute null scanning;

step 22, extracting at least two groups of calibration beams representing the same transverse position and corresponding to the experimental beams, analyzing the detection data of the calibration beams at the preset depth respectively, and correspondingly obtaining at least two groups of sampling data;

step 23, calculating to obtain standard noise data according to a preset discrete relation and the sampling data;

step 232, using the apodization coefficient as weight, respectively executing amplitude compensation to the sampling data to obtain compensation data;

241, outputting a detection beam trigger signal to control a plurality of ultrasonic units to send out detection beams;

step 242, receiving a plurality of echo signals respectively corresponding to the probe beams, performing beam forming on the echo signals, and respectively corresponding to a plurality of receiving beams;

step 243, respectively subtracting the standard noise data from the plurality of received beams to correspondingly obtain a plurality of noise reduction beams;

and 244, respectively carrying out scale amplification on the noise reduction beams, and carrying out ultrasonic imaging by using the amplified noise reduction beams.

The ultrasound imaging process in this embodiment includes transmitting a probe beam, receiving an echo signal, beamforming the echo signal to obtain a receive beam, and then performing noise reduction on the receive beam and using the receive beam for subsequent imaging. In this embodiment, the noise reduction processing is performed by subtracting the received beam from the standard noise data obtained in the foregoing process, and using the beam corresponding to the difference as the noise reduction beam. Such as:

Beamline_new＝Beamline-Cutoff；

wherein Beamline is a receiving beam, Beamline _ new is a noise reduction beam, and Cutoff is standard noise data, and as can be seen from the foregoing embodiment, the standard noise data Cutoff may be the Cutoff₁Or Cutoff₂Standard noise data calculated for performing other ultrasound imaging noise reduction methods may also be calculated.

Of course, the subtraction operation can also be performed by receiving beam composite forming imaging beam data, and after subtraction, the scaling and subsequent imaging processing actions are performed, so that the expected technical effect can be achieved. Such as:

Sig_final＝Sig(abs(Sig)≥Cutoff)-Cutoff；

where Sig _ final is the noise-reduced imaging beam, Sig is the non-noise-reduced imaging beam, Cutoff is the standard noise data, abs (Sig) ≧ Cutoff is the condition for performing the above operation, indicating that the above subtraction operation is performed when the absolute value of the data of the non-noise-reduced imaging beam Sig is equal to or greater than the standard noise data Cutoff.

Of course, the subtraction can be performed by selecting one of the receiving beam and the imaging beam, or by subtracting both beams, and the subtraction can be adjusted according to the needs of those skilled in the art.

The method for noise reduction in ultrasonic imaging provided by the second embodiment of the embodiment specifically includes:

step 21, when the ultrasonic imaging device is judged to meet the preset precondition, outputting an experiment beam trigger signal, and controlling at least two ultrasonic units at different transverse positions to respectively send out experiment beams to execute null scanning;

step 22, extracting at least two groups of calibration beams representing the same transverse position and corresponding to the experimental beams, analyzing the detection data of the calibration beams at the preset depth respectively, and correspondingly obtaining at least two groups of sampling data;

step 23, calculating to obtain standard noise data according to a preset discrete relation and the sampling data;

step 232, using the apodization coefficient as weight, respectively executing amplitude compensation to the sampling data to obtain compensation data;

241, outputting a detection beam trigger signal to control a plurality of ultrasonic units to send out detection beams;

step 242, receiving a plurality of echo signals respectively corresponding to the probe beams, performing beam forming on the echo signals, and respectively corresponding to a plurality of receiving beams;

step 243', respectively performing logarithmic compression on the received beams and the standard noise data, and performing subtraction operation on the compressed received beams and the standard noise data to correspondingly obtain a plurality of noise reduction beams;

and 244, respectively carrying out scale amplification on the noise reduction beams, and carrying out ultrasonic imaging by using the amplified noise reduction beams.

In executing step 243' of the second embodiment of this embodiment, it should be noted that since the subtracted number corresponding to the subtraction operation is the received beam after performing the logarithmic compression, the standard noise data also needs to perform the logarithmic compression, and the corresponding dB value is obtained by calculation, so as to be used for calculation. Such as:

Sig_log_final＝Sig_log(Sig_log≥20log₁₀(Cutoff))-20log₁₀(Cutoff)；

wherein Sig _ log _ final is an imaging beam subjected to noise reduction, Sig _ log is an imaging beam subjected to no noise reduction and log compression, Cutoff is the standard noise data, and 20log₁₀(Cutoff) is a dB value after logarithmic compression is performed on the standard noise data, and Sig _ log is more than or equal to 20log₁₀(Cutoff) is a condition for performing the above operation, and indicates that data of the imaging beam Sig _ log which is not noise-reduced and is logarithmically compressed is 20log or more of the dB value of the standard noise data₁₀(Cutoff) the above subtraction is performed.

Further, in order to ensure the robustness of the algorithm, the ultrasonic imaging noise reduction method provided by the invention can be configured to perform the above operations on a plurality of positions/pixel points of a far-field position part of an image, and perform noise reduction operations by averaging results of different sampling points (i.e. positions of the sampling data corresponding to beams) or taking a maximum value as a threshold value. For non-overlapping parallel receive beamforming imaging, the algorithm may be configured to perform an algorithm operation using laterally adjacent receive beams instead of the above-mentioned calibration beam analyzed at the same position. For multi-angle plane wave imaging, a single-angle beam of multi-angle plane waves at the same position can be configured to replace the calibration beam obtained by analyzing at the same position for algorithm operation. For synthetic aperture imaging, the method may be configured to perform an algorithm operation by using beams corresponding to receiving apertures with different sizes at the same position, instead of the calibration beam analyzed at the same position.

In addition, for various embodiments and examples corresponding to the ultrasound imaging noise reduction method provided by the present invention, the order of the steps may be adjusted according to the needs of those skilled in the art without affecting the technical effect, and it should be noted that a plurality of ultrasound imaging noise reduction methods provided by the present invention cannot be considered in isolation, and the steps of each embodiment or example may be combined and/or replaced, and thus the resulting new embodiments are included in the scope of the present invention.

In summary, the ultrasonic imaging noise reduction method provided by the invention extracts at least two groups of calibration beams representing the same position after executing the empty scanning to output the experimental beams, performs special data extraction and processing on the calibration beams, and executes noise reduction processing on the ultrasonic imaging process by using the obtained standard noise data as a global noise threshold, and has the technical effects of high noise reduction speed and high adaptive degree; compared with the prior art of simply utilizing noise data in a frame detected by empty scanning to perform noise reduction, the method has the advantages that the algorithm process is simpler, the characteristics of formed beams are fully utilized, and the method is applied to ultrasonic imaging formed by parallel receiving beams, and the noise reduction effect is more obvious.

It should be understood that although the present description refers to embodiments, not every embodiment contains only a single technical solution, and such description is for clarity only, and those skilled in the art should make the description as a whole, and the technical solutions in the embodiments can also be combined appropriately to form other embodiments understood by those skilled in the art.

The above-listed detailed description is only a specific description of a possible embodiment of the present invention, and they are not intended to limit the scope of the present invention, and equivalent embodiments or modifications made without departing from the technical spirit of the present invention should be included in the scope of the present invention.