An ultrasonic focusing random arrangement method and system for reducing sidelobes

Abstract

The application discloses an ultrasonic focusing random arrangement method for reducing sidelobes, comprising the following steps: generating points randomly in a specified two-dimensional region, screening the generated points according to preset conditions, forming a two-dimensional point array, and generating a current arrangement according to the two-dimensional point array; projecting all the two-dimensional points in the two-dimensional point array onto a specified spherical surface to obtain three-dimensional coordinates of all the points; importing the three-dimensional coordinates of all the points into an acoustic field simulation software to obtain a time spectrum diagram corresponding to the current arrangement; and calculating a maximum intensity ratio according to data of the time spectrum diagram, and outputting the current arrangement when the maximum intensity ratio is less than a preset value. The application generates elements of a specified size with restrictions in a specified two-dimensional region and generates coordinates, then projects the coordinates onto a spherical surface to obtain three-dimensional coordinates through a spherical surface formula, finally imports the three-dimensional coordinates into a simulation software for simulation, tests a deflection effect, and further screens an arrangement mode with a deflection capacity meeting requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of for reducing sidelobe ultrasonic focusing random arrangement method and system. BACKGROUND

[0002] The application of focused ultrasound is very wide in medical field, but most of the applications are concave self-focusing form, and almost no phased. Focused ultrasound is mainly applied in tissue ablation and nerve stimulation direction, the principle is to use the cavitation effect and thermal effect of ultrasonic wave. For ablation, the temperature of focused focal point position can be as high as 65 degrees Celsius, while using thermal effect and cavitation effect to act on the corresponding tissue, to achieve the purpose of ablation. For nerve stimulation, it is mainly used for activation of the function of a certain area by using thermal effect, with low intensity.

[0003] Phased array acoustic field focusing algorithm has always been the core of phased array research, and the advantage of algorithm will directly lead to focusing effect and precision. Since phased array is applied to ultrasonic field, there are mainly pseudo-inverse algorithm, genetic algorithm, equal sound path algorithm and time reversal algorithm which has been studied very hot in recent years about phased array focusing algorithm.

[0004] Ultrasonic planar array probe is the application of phased array technology, but different arrangement will affect the intensity of focal point. If the deflection of preset focal point and self-focusing point is increased, a second focal point will appear. Under the condition of same deflection angle, how to reduce the intensity of the second focal point is a problem that needs to be overcome. SUMMARY

[0005] To solve the problem that the intensity of second focal point is large when deflection in the existing arrangement, the present application provides a kind of ultrasonic focusing random arrangement method for reducing sidelobe, which generates array elements of specified size with restrictions in a specified two-dimensional region and generates coordinates, then projects to the spherical surface by spherical formula to obtain three-dimensional coordinates, finally imports the three-dimensional coordinates into simulation software for simulation to test the deflection effect, and then selects the arrangement mode with required deflection ability.

[0006] According to one aspect of the present application, a kind of ultrasonic focusing random arrangement method for reducing sidelobe is provided, comprising:

[0007] Randomly generate points in a specified two-dimensional region, and screen the generated points according to preset conditions to form a two-dimensional point array, and generate the current arrangement according to the two-dimensional point array;

[0008] Project all two-dimensional points in the two-dimensional point array to a specified spherical surface to obtain three-dimensional coordinates of all points;

[0009] Import the three-dimensional coordinates of all points into acoustic field simulation software to obtain the time spectrum diagram corresponding to the current arrangement mode;

[0010] According to data of the time spectrum diagram, a maximum intensity ratio = 20xlog10 (side lobe intensity / main lobe intensity) is calculated, and when the maximum intensity ratio is less than a preset value, the current arrangement mode is output.

[0011] As a further technical solution, points are randomly generated in a specified two-dimensional region, and the generated points are screened according to a preset condition, including:

[0012] A center point of a circle is set.

[0013] Random generation of candidate points is performed in a loop, and it is determined whether the currently generated candidate point meets the preset condition.

[0014] When the currently generated candidate point is located in the circle and the distance from the generated candidate point to the known point meets the distance constraint, the currently generated candidate point is added to the two-dimensional point array as a qualified point.

[0015] As a further technical solution, the method further includes:

[0016] When the currently generated candidate point is not located in the circle, the step of randomly generating the candidate point is returned, and the random generation of the candidate point is re-performed.

[0017] As a further technical solution, the method further includes:

[0018] When the currently generated candidate point is located in the circle, but the distance from the generated candidate point to the known point does not meet the distance constraint, the step of randomly generating the candidate point is returned, and the random generation of the candidate point is re-performed.

[0019] As a further technical solution, the method further includes:

[0020] The distance constraint between the currently generated candidate point and the known point is set: taking the currently generated candidate point as the center of a circle, taking a set diameter to define a range, searching for the known point outside the range, obtaining the distance between the known point and the currently generated candidate point, and if the distance is greater than or equal to the value of the set diameter, it is considered that the distance constraint is met.

[0021] As a further technical solution, after obtaining the time spectrum diagram corresponding to the current arrangement mode, the method further includes:

[0022] The time spectrum waveform is locally sectioned, and the main lobe intensity and the side lobe intensity of the time spectrum waveform are calculated.

[0023] According to an aspect of the present application, an ultrasonic focusing random arrangement system for reducing side lobes is provided, including:

[0024] A first main module is configured to randomly generate points in a specified two-dimensional region, screen the generated points according to a preset condition, form a two-dimensional point array, and generate a current arrangement according to the two-dimensional point array.

[0025] a second main module for projecting all two-dimensional points in the two-dimensional point array onto a specified spherical surface to obtain three-dimensional coordinates of all points;

[0026] a third main module for importing the three-dimensional coordinates of all points into sound field simulation software to obtain a time spectrum diagram corresponding to the current arrangement mode;

[0027] a fourth main module for calculating a maximum intensity ratio = 20 x log10 (side lobe intensity / main lobe intensity) according to data of the time spectrum diagram, and outputting the current arrangement mode when the maximum intensity ratio is less than a preset value.

[0028] According to an aspect of the present application, a non-transitory computer readable storage medium is provided, which stores computer instructions for causing a computer to execute the method for reducing side lobes of ultrasonic focusing random arrangement.

[0029] According to an aspect of the present application, an ultrasonic surface array probe is provided, which is configured with the system for reducing side lobes of ultrasonic focusing random arrangement.

[0030] Compared with the prior art, the present application has the following advantages:

[0031] The present application generates elements of a specified size within a specified two-dimensional region with limitations, generates two-dimensional point coordinates, projects onto a spherical surface through a spherical formula to obtain three-dimensional coordinates, and finally imports the three-dimensional coordinates into simulation software for simulation, tests the deflection effect, and selects a random arrangement meeting the requirements according to the deflection effect. Compared with the existing arrangement mode, the present application produces lower side lobe intensity under the same angle deflection. BRIEF DESCRIPTION OF DRAWINGS

[0032] To make the technical solutions of the present application or the prior art clearer, the following will briefly introduce the drawings used in the embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort based on these drawings.

[0033] Figure 1 A flowchart of a method for reducing side lobes of ultrasonic focusing random arrangement is provided for the embodiments of the present application.

[0034] Figure 2 A flowchart of generating a two-dimensional point array is provided for the embodiments of the present application.

[0035] Figure 3 A schematic diagram of randomly generating an arrangement is provided for the embodiments of the present application.

[0036] Figure 4 The time spectrum diagram and the sidelobe diagram provided by the embodiment of the present application.

[0037] Figure 5 The time spectrum diagram and the sidelobe diagram provided by the Fermat double helix arrangement mode of the embodiment of the present application. DETAILED DESCRIPTION

[0038] The current probe array arrangement includes Archimedes arrangement and Fermat arrangement, and the focal point deflection ability of the array elements of different arrangements is different, and the array element arrangement with excellent focal point deflection ability is obtained through random generation, and the sidelobe intensity can be smaller in the deflection of a fixed angle.

[0039] The technical solutions of the embodiments of the present application will be described clearly and completely in combination with the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0040] As shown in Figure 1 The present application provides an ultrasonic focusing random arrangement method for reducing sidelobe. Firstly, points are randomly generated in a specified two-dimensional region, and the generated points are screened according to a preset condition to form a two-dimensional point array, and a current arrangement is generated according to the two-dimensional point array. Then, all two-dimensional points in the two-dimensional point array are projected onto a specified spherical surface to obtain three-dimensional coordinates of all points. Then, the three-dimensional coordinates of all points are imported into an acoustic field simulation software to obtain a time spectrum diagram corresponding to the current arrangement mode. Finally, according to the data of the time spectrum diagram, the maximum intensity ratio = 20xlog10(sidelobe intensity / main lobe intensity) is calculated, and the current arrangement mode is output when the maximum intensity ratio is less than a preset value.

[0041] In the specific embodiment, the two-dimensional point generation is to use Figure 2 The code is generated by using the logic, and the required two-dimensional point coordinates are finally saved in the final array.

[0042] As shown in Figure 2 The two-dimensional point array generation specifically includes:

[0043] S1, initialization and parameter setting, including the diameter size of each point in the array element.

[0044] S2, setting an initial center point and its radius, and the circular region defined by the center point and its radius is the array element region of the point.

[0045] S3, according to the order of i=2→numPoints (total number of points), the following process is executed in a loop:

[0046] S3.1, randomly generating a candidate point;

[0047] S3.2, judging whether the currently generated candidate point is located in the circle, if yes, entering S3.3, otherwise returning to S3.1;

[0048] S3.3, judging whether the distance between the currently generated candidate point and the existing point is qualified, if yes, accepting the currently generated candidate point to join the array, otherwise returning to S3.1.

[0049] The judging whether the distance between the currently generated candidate point and the existing point is qualified in S3.3 refers to judging whether the distance between the currently generated candidate point and the existing point satisfies the preset distance constraint. The distance constraint is that a range is defined with the currently generated candidate point as the center and a set diameter (such as 11 mm), searching for the existing point outside the range, obtaining the distance between the existing point and the currently generated candidate point, and if the distance is greater than or equal to 11 mm, it is considered that the distance constraint is satisfied. The distance constraint is set to avoid the overlap of points and make the arrangement of the generated points more reasonable.

[0050] S4, after the loop ends, outputting all the generated points and performing statistics, drawing the circle and the points according to the statistical results, and generating a circular arrangement diagram, such as Figure 3 The left upper diagram shows a schematic diagram of generating random points outside the radius of 5.5 mm of the existing points.

[0051] After obtaining the two-dimensional array of all the points, the randomly generated two-dimensional points are projected onto the specified spherical surface, and the three-dimensional coordinates are obtained, wherein the Z-axis data can be obtained according to the X-axis and Y-axis data of the points, and can be directly calculated by the following formula:

[0052] .

[0053] After obtaining the three-dimensional coordinates of all the points, the three-dimensional coordinates of all the points are imported into the simulation software for comparison, that is, by generating a time spectrum diagram, the intensity of the sidelobe generated is compared. For example, MATLAB and k-wave library can be used for simulation screening.

[0054] As shown in Figure 4 The left upper diagram shows a time spectrum diagram generated by the arrangement mode provided by the embodiment of the application, from which the main lobe data and the section can be obtained, and the positions of the focal point and the sidelobe can be seen. From Figure 4 The left upper diagram shows a time spectrum diagram generated by the arrangement mode provided by the embodiment of the application, from which the main lobe data and the section can be obtained, and the positions of the focal point and the sidelobe can be seen. From

[0055] As shown in Figure 5 The left upper diagram shows a time spectrum diagram generated by the arrangement mode provided by the embodiment of the application, from which the main lobe data and the section can be obtained, and the positions of the focal point and the sidelobe can be seen. FromFigure 5 The position marked in the upper left corner is locally sectioned to obtain the two-dimensional slice diagram after local sectioning at the lower left corner and the three-dimensional schematic diagram in the upper right corner.

[0056] As shown below, Table 1 is the main lobe intensity Max Pressure, side lobe intensity Max Pressure 2 and maximum intensity ratio Max Pressure ratio obtained by the random arrangement method provided by the embodiment of the application. Table 2 is the main lobe intensity Max Pressure, side lobe intensity Max Pressure 2 and maximum intensity ratio Max Pressure ratio obtained by the Fermat double helix arrangement method.

[0057] Wherein, the parameters of Max Pressure ratio are obtained from Max Pressure and Max Pressure 2, and the formula is as follows:

[0058]

[0059] The smaller the obtained ratio is, the greater the difference between the intensity of the side lobe and the focal point is, and the better the focusing effect of the probe is. As shown in Table 1 and Table 2, the Max Pressure ratio obtained by the random arrangement method described in the embodiment of the application is -20.6967, and the Max Pressure ratio obtained by the Fermat double helix arrangement method is -17.7419. It can be seen that the deflection effect of the random arrangement method described in the embodiment of the application is better.

[0060] In actual application, through several rounds of attempts, the arrangement method with better random arrangement effect can be obtained through simulation. As an optimization, the threshold of the maximum intensity ratio can be taken as 20, and when the maximum intensity ratio Max Pressure ratio is less than 20, it can be considered that the random arrangement effect is better.

[0061] From Figure 4 and Figure 5 It can also be seen from the comparison that the maximum intensity ratio of the random arrangement method described in the application is smaller, and therefore this random arrangement method can find an arrangement array with better effect.

[0062] Table 1 Random arrangement method of the application

[0063] .

[0064] Table 2 Fermat double helix arrangement method

[0065] .

[0066] The implementation basis of each embodiment of the present application is realized by the processing of the device with the processor function. Therefore, in engineering practice, the technical solutions and functions of each embodiment of the present application are packaged into various modules. Based on the above-mentioned embodiments, the embodiment of the present application provides an ultrasonic focusing random arrangement system for reducing sidelobes, which is used to execute the ultrasonic focusing random arrangement method for reducing sidelobes in the above-mentioned method embodiment.

[0067] The system comprises: a first main module for randomly generating points in a specified two-dimensional region, screening the generated points according to a preset condition, forming a two-dimensional point array, and generating a current arrangement according to the two-dimensional point array; a second main module for projecting all two-dimensional points in the two-dimensional point array onto a specified spherical surface to obtain three-dimensional coordinates of all points; a third main module for importing the three-dimensional coordinates of all points into acoustic field simulation software to obtain a time spectrum diagram corresponding to the current arrangement mode; and a fourth main module for calculating a maximum intensity ratio = 20xlog10 (sidelobe intensity / main lobe intensity) according to the data of the time spectrum diagram, and outputting the current arrangement mode when the maximum intensity ratio is less than a preset value.

[0068] The ultrasonic focusing random arrangement system for reducing sidelobes provided by the embodiment of the present application adopts the above-mentioned modules, generates elements of a specified size with restrictions in a specified two-dimensional region and generates coordinates, projects onto a spherical surface through a spherical formula to obtain three-dimensional coordinates, and finally imports the three-dimensional coordinates into simulation software for simulation to test the deflection effect, and then selects an arrangement mode with a deflection ability meeting the requirements.

[0069] It should be noted that the system embodiment provided by the present application is used to implement the method in the above-mentioned method embodiment, and is also used to implement the method in other method embodiments provided by the present application. The difference is only that the corresponding function modules are set, and the principle is basically the same as that of the above-mentioned system embodiment provided by the present application. As long as the person skilled in the art improves the modules in the above-mentioned system embodiment on the basis of the above-mentioned system embodiment, refers to the specific technical solutions in other method embodiments, obtains the corresponding technical means by combining technical features, and the technical solutions composed of these technical means, as long as the technical solutions have practicality, the corresponding system class embodiment is obtained, which is used to implement the method in other method class embodiments. For example:

[0070] Based on the content of the above-mentioned system embodiment, as a preferred embodiment, the first main module in the ultrasonic focusing random arrangement system for reducing sidelobes provided by the embodiment of the present application is further used to execute the following instructions:

[0071] Set the center point of the circle;

[0072] The random generation of the candidate point is executed in a loop, and it is determined whether the currently generated candidate point meets a preset condition;

[0073] When the currently generated candidate point is located in the circle and the distance from the currently generated candidate point to the known point meets the distance constraint, the currently generated candidate point is added to the two-dimensional point array as a qualified point.

[0074] Based on the content of the above system embodiment, as a preferred embodiment, the first main module is further used to execute the following instructions in the system for reducing sidelobes provided in the embodiment of the application:

[0075] When the currently generated candidate point is not located in the circle, the step of randomly generating the candidate point is returned to, and the random generation of the candidate point is re-executed.

[0076] Based on the content of the above system embodiment, as a preferred embodiment, the first main module is further used to execute the following instructions in the system for reducing sidelobes provided in the embodiment of the application:

[0077] When the currently generated candidate point is located in the circle, but the distance from the currently generated candidate point to the known point does not meet the distance constraint, the step of randomly generating the candidate point is returned to, and the random generation of the candidate point is re-executed.

[0078] Based on the content of the above system embodiment, as a preferred embodiment, the first main module is further used to execute the following instructions in the system for reducing sidelobes provided in the embodiment of the application:

[0079] The distance constraint of the currently generated candidate point and the known point is set: a range is defined with the currently generated candidate point as the center and a set diameter, the known point outside the range is searched, the distance between the known point and the currently generated candidate point is obtained, and if the distance is greater than or equal to the value of the set diameter, it is considered that the distance constraint is met.

[0080] Based on the content of the above system embodiment, as a preferred embodiment, the third main module is further used to execute the following instructions in the system for reducing sidelobes provided in the embodiment of the application:

[0081] The time spectrum waveform is locally cut, and the main lobe intensity and the sidelobe intensity of the time spectrum waveform are calculated.

[0082] Based on the same inventive concept as the foregoing embodiments, the embodiment of the application further provides a non-transitory computer readable storage medium, the non-transitory computer readable storage medium stores computer instructions, and the computer instructions make the computer execute the method for reducing sidelobes of ultrasonic focusing random arrangement.

[0083] Based on the same inventive concept as the foregoing embodiments, the embodiments of the present application also provide an ultrasonic surface array probe configured with the ultrasonic focusing random arrangement system for reducing sidelobes.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present application.

Claims

1. A method for random arrangement of focused ultrasound lobes to reduce side lobes, characterized in that, To reduce the intensity of the second focus at a fixed deflection angle, including: Points are randomly generated within a specified two-dimensional area, and the generated points are filtered according to preset conditions, including: setting the center point and the distance constraints between the currently generated candidate point and existing points; cyclically generating candidate points and determining whether the currently generated candidate point meets the preset conditions; when the currently generated candidate point is located inside the circle and the distance to existing points meets the distance constraints, the currently generated candidate point is added to the two-dimensional point array as a qualified point, and the current arrangement is generated according to the two-dimensional point array. Project all the two-dimensional points in the array onto a specified sphere to obtain the three-dimensional coordinates of all the points. Import the three-dimensional coordinates of all points into the sound field simulation software to obtain the time spectrum diagram corresponding to the current arrangement. Perform a local cross section on the time spectrum waveform and calculate the main lobe intensity and side lobe intensity of the time spectrum waveform. Based on the data from the time-spectrum, calculate the maximum intensity ratio = The smaller the maximum intensity ratio, the better the focusing effect of the ultrasonic probe, and when the maximum intensity ratio is less than a preset value, the current arrangement is output.

2. The method for random arrangement of focused ultrasound lobes to reduce side lobes according to claim 1, characterized in that, The method further includes: If the currently generated candidate point is not located inside the circle, return to the step of randomly generating candidate points and re-generate candidate points randomly.

3. The method for random arrangement of focused ultrasound lobes to reduce side lobes according to claim 1, characterized in that, The method further includes: If a currently generated candidate point is located inside the circle but its distance from an existing point does not meet the distance constraint, return to the step of randomly generating candidate points and start generating candidate points randomly again.

4. The method for random arrangement of focused ultrasound lobes to reduce side lobes according to claim 1, characterized in that, The method further includes: Using the currently generated candidate point as the center, and defining a range with a set diameter, search for known points outside this range, and obtain the distance between the known points and the currently generated candidate point. If the distance is greater than or equal to the value of the set diameter, it is considered that the distance constraint is satisfied.

5. An ultrasound focusing random arrangement system for reducing side lobes, characterized in that, To reduce the intensity of the second focus at a fixed deflection angle, including: The first main module is used to randomly generate points within a specified two-dimensional area and filter the generated points according to preset conditions, including: setting the center point and the distance constraints between the currently generated candidate point and existing points; cyclically executing the random generation of candidate points and determining whether the currently generated candidate point meets the preset conditions; when the currently generated candidate point is located inside the circle and the distance to the existing point meets the distance constraints, adding the currently generated candidate point as a qualified point to the two-dimensional point array, and generating the current arrangement according to the two-dimensional point array; The second main module is used to project all the two-dimensional points in the two-dimensional point array onto a specified sphere to obtain the three-dimensional coordinates of all points. The third main module is used to import the three-dimensional coordinates of all points into the sound field simulation software, obtain the time spectrum diagram corresponding to the current arrangement, perform local cross-sections on the time spectrum waveform, and calculate the main lobe intensity and side lobe intensity of the time spectrum waveform. The fourth main module is used to calculate the maximum intensity ratio based on the data from the time-spectrum. The smaller the maximum intensity ratio, the better the focusing effect of the ultrasonic probe, and when the maximum intensity ratio is less than a preset value, the current arrangement is output.

6. A non-transitory computer-readable storage medium, characterized in that, The non-transitory computer-readable storage medium stores computer instructions that cause the computer to perform a method for reducing side lobes using ultrasound focusing random arrangement as described in any one of claims 1 to 4.

7. An ultrasonic array probe, characterized in that, It is equipped with an ultrasound focusing random arrangement system for reducing side lobes as described in claim 5.

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