Sound pressure measurement method, sound pressure measurement device, and computer-readable storage medium

Abstract

The invention provides a sound pressure measuring method, a sound pressure measuring device and a computer readable storage medium. The sound pressure measuring method comprises the following steps: emitting a detection light beam along a preset path; when the to-be-detected sound wave is not loaded, acquiring an initial irradiation position of the detection light beam and initial illumination of the initial irradiation position; when the sound wave to be detected is loaded, obtaining deviation illumination of a deflection irradiation position and an initial irradiation position after the detection light beam penetrates through the sound field of the sound wave to be detected; and determining the irradiation position offset of the deflection irradiation position relative to the initial irradiation position and the illumination deviation value of the deviation illumination relative to the initial illumination, and determining the sound pressure value of the sound field of the sound wave to be measured at each position on the preset path according to the irradiation position offset and the illumination deviation value. The invention provides a sound pressure measurement method, a sound pressure measurement device and a computer readable storage medium, which can improve the sound pressure measurement accuracy, the measurement range and the spatial resolution so as to meet the measurement requirement of the sound pressure of an HIFU sound field.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ultrasound, in particular to an acoustic pressure measurement method, an acoustic pressure measurement device and a computer readable storage medium. BACKGROUND

[0002] High Intensity Focused Ultrasound (HIFU) can be emitted from outside the body to penetrate into the body, and realize acoustic energy convergence in a specific target area or lesion in the body, so as to realize local thermal damage or mechanical damage of the specific target area or lesion by high-energy acoustic waves, thereby realizing non-invasive and non-invasive treatment. The acoustic field parameters of HIFU are very important physical parameters for the effectiveness and safety of HIFU, and are crucial for optimizing and standardizing the application and development of HIFU.

[0003] However, in the prior art, the acoustic pressure measurement method has the problems of low measurement accuracy, low measurement range and low spatial resolution, and it is difficult to meet the measurement requirements of HIFU acoustic field acoustic pressure. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art, and proposes an acoustic pressure measurement method, an acoustic pressure measurement device and a computer readable storage medium, which can improve the acoustic pressure measurement accuracy, the measurement range and the spatial resolution, thereby meeting the measurement requirements of HIFU acoustic field acoustic pressure.

[0005] To achieve the purpose of the present application, an acoustic pressure measurement method is provided, comprising the following steps:

[0006] emitting a detection light beam along a preset path;

[0007] When the to-be-measured acoustic wave is not loaded, the initial irradiation position of the detection light beam and the initial irradiance of the initial irradiation position are obtained;

[0008] When the to-be-measured acoustic wave is loaded, the deflection irradiation position of the detection light beam after penetrating the to-be-measured acoustic wave field and the deviation irradiance of the initial irradiation position are obtained;

[0009] determining the irradiation position offset of the deflection irradiation position relative to the initial irradiation position and the irradiance deviation value of the deviation irradiance relative to the initial irradiance, and determining the acoustic pressure value of each position of the to-be-measured acoustic wave field on the preset path according to the irradiation position offset and the irradiance deviation value.

[0010] Optionally, the obtaining of the deflection irradiation position of the detection light beam after penetrating the to-be-measured acoustic wave field and the deviation irradiance of the initial irradiation position specifically comprises:

[0011] acquiring the deflected irradiation positions of the detection light beam penetrating the sound field of the to-be-tested sound wave at a plurality of to-be-tested time instants within one period of the to-be-tested sound wave and the deviated irradiance at the initial irradiation position;

[0012] The determination of the irradiation position offset of the deflected irradiation position relative to the initial irradiation position and the irradiance deviation value of the deviated irradiance relative to the initial irradiance includes:

[0013] The determination of the irradiation position offset of the deflected irradiation position relative to the initial irradiation position and the irradiance deviation value of the deviated irradiance relative to the initial irradiance includes:

[0014] The determination of the irradiation position offset of the deflected irradiation position relative to the initial irradiation position and the irradiance deviation value of the deviated irradiance relative to the initial irradiance includes:

[0015] The determination of the irradiation position offset of the deflected irradiation position relative to the initial irradiation position and the irradiance deviation value of the deviated irradiance relative to the initial irradiance includes:

[0016]

[0017] wherein a and b are correction coefficients relative to a standard sound wave of the to-be-tested sound wave, x is a coordinate in a first direction, y is a coordinate in a second direction, z is a coordinate in a third direction, the first direction and the second direction are perpendicular and located on a first plane perpendicular to a projection plane of the sound field of the to-be-tested sound wave, the third direction is perpendicular to the first plane, t is the to-be-tested time instant, ΔI is the irradiance deviation value, v is the irradiation position offset, L is a length of the sound field of the to-be-tested sound wave in the third direction, and ▽n is the refractive index gradient.

[0018] The determination of the irradiation position offset of the deflected irradiation position relative to the initial irradiation position and the irradiance deviation value of the deviated irradiance relative to the initial irradiance includes:

[0019] The determination of the irradiation position offset of the deflected irradiation position relative to the initial irradiation position and the irradiance deviation value of the deviated irradiance relative to the initial irradiance includes:

[0020]

[0021] wherein n is the measured refractive index, n0 is the refractive index of the medium loaded with the to-be-measured acoustic wave when the medium is not loaded with the to-be-measured acoustic wave, is the photoelastic coefficient of the medium loaded with the to-be-measured acoustic wave, and p is the acoustic pressure value.

[0022] Optionally, the detection light beam is a Gaussian light beam.

[0023] Optionally, the initial irradiation position and the deflected irradiation position of the Gaussian light beam are both the irradiance peak positions of the Gaussian light beam.

[0024] Optionally, the acoustic pressure measurement method further comprises the steps of:

[0025] setting a three-dimensional matrix for the to-be-measured acoustic wave field and determining the acoustic pressure value of each element of the three-dimensional matrix.

[0026] Optionally, the step of setting a three-dimensional matrix for the to-be-measured acoustic wave field and determining the acoustic pressure value of each element of the three-dimensional matrix specifically comprises:

[0027] emitting the detection light beam along multiple preset paths in the three-dimensional direction of the three-dimensional matrix;

[0028] determining the acoustic pressure value of each position corresponding to each element of the three-dimensional matrix on the multiple preset paths.

[0029] Optionally, the step of emitting the detection light beam along multiple preset paths in the three-dimensional direction of the three-dimensional matrix specifically comprises:

[0030] setting a first plane perpendicular to the projection plane of the to-be-measured acoustic wave field;

[0031] making the to-be-measured acoustic wave complete one revolution by multiple self-rotations;

[0032] emitting the detection light beam along a preset path perpendicular to the first plane between adjacent two self-rotations of the to-be-measured acoustic wave and after one revolution of the to-be-measured acoustic wave, and making the detection light beam scan the first plane.

[0033] Optionally, the step of emitting the detection light beam along a preset path perpendicular to the first plane and making the detection light beam scan the first plane specifically comprises:

[0034] setting multiple path groups, each of the path groups comprising multiple preset paths, the multiple preset paths of the same path group being distributed at intervals in a first direction of the first plane parallel to the projection plane of the to-be-measured acoustic wave field, and the multiple path groups being distributed at intervals in a second direction of the first plane perpendicular to the first direction.

[0035] The detection light beams are sequentially emitted in order of the plurality of path groups.

[0036] The application further provides a sound pressure measuring device for performing the sound pressure measuring method provided by the application, the sound pressure measuring device comprising a light source, an acquisition component and a controller, the light source being configured to emit the detection light beams, the acquisition component being configured to acquire the detection light beams, and the controller being signal connected with the light source and the acquisition component respectively and configured to control the start and stop of the light source and the acquisition of the detection light beams by the acquisition component.

[0037] Optionally, the sound pressure measuring device further comprises a first moving component, a second moving component and a rotating component, the first moving component being connected with the light source and configured to drive the light source to move in a first direction and a second direction, the first direction and the second direction being perpendicular and located on a first plane perpendicular to a projection plane of the sound field of the to-be-measured sound wave, the second moving component being connected with the acquisition component and configured to move synchronously with the first moving component and drive the acquisition component to move synchronously with the light source, and the rotating component being connected with a sound source configured to provide the to-be-measured sound wave and configured to drive the sound source to rotate.

[0038] Optionally, the light source has a variation rate of output power less than or equal to 1%.

[0039] The application further provides a computer readable storage medium storing a computer program, the computer program being capable of realizing the sound pressure measuring method provided by the application when executed by a processing module.

[0040] The application has the following advantages:

[0041] The sound pressure measuring method provided by the application can acquire the initial irradiation position of the detection light beams and the initial irradiance of the initial irradiation position when the to-be-measured sound wave is not loaded, acquire the deflected irradiation position of the detection light beams after penetrating the sound field of the to-be-measured sound wave and the deviation irradiance of the initial irradiation position when the to-be-measured sound wave is loaded, and determine the irradiation position offset of the deflected irradiation position relative to the initial irradiation position and the irradiance deviation value of the deviation irradiance relative to the initial irradiance, so that the sound pressure values of each position of the sound field of the to-be-measured sound wave on the preset path can be determined according to the irradiation position offset and the irradiance deviation value. Since the irradiance variation of the detection light beams is more sensitive to the sound pressure of the sound field of the to-be-measured sound wave compared with the irradiation position of the detection light beams, that is, the irradiance of the detection light beams can change greatly when the sound pressure of the sound field of the to-be-measured sound wave changes slightly, and the irradiance variation of the detection light beams can be detected more easily and more accurately, the sound pressure values of each position of the sound field of the to-be-measured sound wave on the preset path can be determined according to the irradiation position offset and the irradiance deviation value, so that the sound pressure measuring accuracy, measuring range and spatial resolution can be improved, and thus the measuring requirement of the sound field sound pressure of HIFU can be met.

[0042] The sound pressure measuring device provided by the present application can improve the sound pressure measuring accuracy, measuring range and spatial resolution by executing the sound pressure measuring method provided by the present application, thereby meeting the measuring requirement of the HIFU sound field sound pressure.

[0043] The computer readable storage medium provided by the present application stores the computer program which can realize the sound pressure measuring method provided by the present application when executed by the processing module, thereby improving the sound pressure measuring accuracy, measuring range and spatial resolution, and further meeting the measuring requirement of the HIFU sound field sound pressure. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 The flow chart of the sound pressure measuring method provided by the embodiment of the present application;

[0045] Figure 2 The structural schematic diagram of the sound pressure measuring device provided by the embodiment of the present application;

[0046] Figure 3 The schematic diagram of the propagation direction of the detection light beam after penetrating the sound field of the sound wave to be measured when the sound wave to be measured is not loaded and the sound wave to be measured is loaded in the embodiment of the present application;

[0047] Figure 4 The schematic diagram of the irradiation position and irradiance of the detection light beam after penetrating the sound field of the sound wave to be measured when the sound wave to be measured is not loaded in the embodiment of the present application;

[0048] Figure 5 The schematic diagram of the irradiation position and irradiance of the detection light beam after penetrating the sound field of the sound wave to be measured when the sound wave to be measured is loaded in the embodiment of the present application;

[0049] Explanation of reference signs:

[0050] 1-light source; 2-acquisition component; 3-controller; 4-first moving component; 5-second moving component; 6-rotating component; 7-signal generator; 8-power amplifier; 9-computer; 10-sound source; 11-holding component; 12-light beam adjusting assembly; 121-focusing lens; 122-needle hole filter; 123-collimating lens. DETAILED DESCRIPTION

[0051] In order for those skilled in the art to better understand the technical solutions of the present application, first, the related sound pressure measuring method and device used by the inventor of the present application for high intensity focused ultrasound are introduced.

[0052] The inventors of this invention conducted sound pressure measurement experiments using invasive hydrophones for high-intensity focused ultrasound (HIFU). The hydrophones used included needle-type hydrophones and thin-film hydrophones based on the piezoelectric effect, as well as fiber optic hydrophones based on optical sensing. The inventors discovered that piezoelectric-based hydrophones are susceptible to electromagnetic interference, leading to significant deviations between the measured and actual sound pressure values, resulting in low accuracy in sound pressure measurement. Furthermore, the sensing interface of piezoelectric hydrophones is rigid. The intrusion of a rigid sensing interface into the medium through which sound waves are loaded can cause premature cavitation, easily damaging the sensing components. Therefore, piezoelectric hydrophones typically can only measure sound pressure levels with amplitudes less than ten megapascals, failing to meet the requirements for measuring the sound pressure of HIFUs with amplitudes reaching tens of megapascals. Moreover, piezoelectric hydrophones typically can only measure the sound pressure of sound waves with frequencies from one MHz to ten MHz, failing to meet the requirements for measuring the sound pressure of HIFUs with frequencies reaching tens to hundreds of MHz, resulting in a limited sound pressure measurement range. The inventors of this invention discovered that fiber optic hydrophones based on optical sensing, because the fiber end is a free end when measuring sound pressure, is easily affected by sound radiation forces and oscillates, leading to a large deviation between the measured sound pressure value and the actual sound pressure value, resulting in low accuracy in sound pressure measurement. Furthermore, the method of measuring sound pressure with hydrophones is problematic because the sensing components of hydrophones need to be immersed in the medium through which the sound waves are carried. As a result, the sensing components can interfere with the sound field. In addition, the measurement method of hydrophones is subject to spatial averaging effects, which leads to a large deviation between the measured sound pressure value and the actual sound pressure value, resulting in low accuracy of sound pressure measurement.

[0053] The inventors of this invention also conducted sound pressure level measurement experiments on HIFU using non-invasive optical measurements. The optical measurement methods employed included schlieren imaging and laser deflection. The inventors discovered that schlieren imaging obtains a two-dimensional projection of the sound field medium in a single image. However, diffracted light from different spatial locations along the beam propagation direction can superimpose and influence each other, making it difficult to accurately reconstruct the sound pressure level. Therefore, schlieren imaging can only measure sound pressure levels with amplitudes below one megapascal. Furthermore, when the local sound pressure level in the sound field is too high, it causes severe beam deflection and high-order diffraction, making it difficult to resolve higher amplitude sound pressure levels from the two-dimensional projection's light intensity distribution information. Therefore, for higher amplitude sound pressure levels, such as those of HIFU, the sound pressure level measured by schlieren imaging deviates significantly from the actual sound pressure level, resulting in low accuracy and a small measurement range. The inventors also found that the spatial resolution of the laser deflection method for measuring sound pressure is only on the order of 2 mm, which is too low to meet the requirements for measuring the sound pressure level of high-frequency sound waves such as those from HIFU.

[0054] The sound pressure measurement method, sound pressure measurement device, and computer-readable storage medium provided by the present invention will be described in detail below with reference to the accompanying drawings.

[0055] like Figure 1 As shown, an embodiment of the present invention provides a method for measuring sound pressure, comprising the following steps:

[0056] S1, emits a detection beam along a preset path;

[0057] S2, when the sound wave to be measured is not loaded, obtain the initial irradiation position of the detection beam and the initial illuminance of the initial irradiation position;

[0058] S3, when loading the sound wave to be tested, obtain the deviation illuminance between the deflection irradiation position and the initial irradiation position after the detection beam penetrates the sound field of the sound wave to be tested;

[0059] S4, determine the irradiation position offset of the deflection irradiation position relative to the initial irradiation position and the irradiation deviation value of the deviation illuminance relative to the initial illuminance, and determine the sound pressure value of the sound field of the sound wave to be measured at each position on the preset path based on the irradiation position offset and the irradiation deviation value.

[0060] The sound pressure measurement method provided in this invention obtains the initial illumination position and initial illuminance of the detection beam when no sound wave is loaded, and obtains the deflection illumination position after the detection beam penetrates the sound field of the sound wave and the deviation illuminance of the initial illumination position when the sound wave is loaded. It also determines the illumination position offset of the deflection illumination position relative to the initial illumination position and the illuminance deviation value of the deviation illuminance relative to the initial illuminance. Based on the illumination position offset and the illuminance deviation value, the sound pressure value of the sound field of the sound wave at each position along a preset path can be determined. Compared to the illumination position of the detection beam, the change in illuminance of the detection beam is more sensitive to the sound pressure of the sound field of the sound wave under test. In other words, when the sound pressure of the sound field of the sound wave under test changes slightly, the illuminance of the detection beam can change significantly. The change in illuminance of the detection beam can be detected more easily and accurately. Therefore, by determining the sound pressure value of the sound field of the sound wave under test at each position on the preset path based on the illuminance offset and the illuminance deviation, the accuracy, measurement range, and spatial resolution of the sound pressure measurement can be improved, thereby meeting the measurement requirements of HIFU sound field sound pressure.

[0061] Specifically, in practical applications, an auxiliary medium can be prepared for the sound wave to be tested to form its sound field. The auxiliary medium must be able to allow the detection beam to penetrate, and its density must be able to change under the influence of the sound pressure of the sound field. After the auxiliary medium is prepared, the detection beam can be emitted along a preset path into the auxiliary medium without loading the sound wave to be tested into it. In this case, as... Figure 3 and Figure 4As shown, the propagation direction of the detection beam does not deflect during its penetration of the auxiliary medium. The position illuminated by the detection beam after penetrating the auxiliary medium is the initial illumination position, and the illuminance at this initial position is the initial illuminance. Afterward, the sound wave to be measured can be loaded onto the auxiliary medium, and the detection beam can continue to be emitted along a preset path into the auxiliary medium. At this time, as... Figure 3 and Figure 5 As shown, during the process of the detection beam penetrating the auxiliary medium, the propagation direction of the detection beam will be deflected due to the influence of the sound pressure of the sound field of the sound wave to be measured. The position of the detection beam after penetrating the auxiliary medium is deflected relative to the initial position, which is called the deflected irradiation position. Furthermore, since the position of the detection beam after penetrating the auxiliary medium is deflected relative to the initial position, the illuminance of the detection beam at the initial position after penetrating the auxiliary medium will deviate from the initial illuminance, which is called the deviation illuminance.

[0062] Subsequently, the irradiation position offset relative to the initial irradiation position and the illuminance deviation value relative to the initial illuminance can be determined. Since the irradiation position offset and illuminance deviation value are the cumulative changes of the detection beam under the influence of the sound pressure of the sound field of the sound wave to be measured during the process of penetrating the sound field of the sound wave to be measured, that is, the detection beam changes due to the influence of the sound pressure of the sound field of the sound wave to be measured at each position on the preset path during the process of penetrating the sound field of the sound wave to be measured. Therefore, after penetrating the sound field of the sound wave to be measured, it finally irradiates the deflection irradiation position with an irradiation position offset relative to the initial irradiation position, and the illuminance at the initial irradiation position is the deviation illuminance with an illuminance deviation value relative to the initial illuminance. Therefore, the sound pressure value of the sound field of the sound wave to be measured at each position on the preset path can be determined based on the irradiation position offset and illuminance deviation value.

[0063] Optionally, the auxiliary medium can be water.

[0064] Optionally, the sound wave to be measured can be high-intensity focused ultrasound (HIFU).

[0065] Optionally, the angle between the preset path and the projection plane of the sound field of the sound wave to be measured can be 0°. That is, the preset path can be parallel to the projection plane of the sound field of the sound wave to be measured.

[0066] Optionally, the detection beam can be a laser.

[0067] In one embodiment of the present invention, obtaining the deviation illuminance between the deflected illumination position and the initial illumination position after the detection beam penetrates the sound field of the sound wave to be measured can specifically include:

[0068] The deviation illuminance between the deflection irradiation position and the initial irradiation position of the detection beam after penetrating the sound field of the sound wave under test at multiple test moments within one cycle of the sound wave under test is obtained.

[0069] Determining the offset of the deflected illumination position relative to the initial illumination position and the illuminance deviation value relative to the initial illuminance, and determining the sound pressure value of the sound field of the sound wave under test at each position on the preset path based on the offset of the illumination position and the illuminance deviation value, can specifically include:

[0070] Determine multiple irradiation position offsets relative to the initial irradiation position and multiple illuminance deviations relative to the initial illuminance. Based on the multiple irradiation position offsets and multiple illuminance deviations that correspond one-to-one with multiple test times, determine the sound pressure value of the sound field of the sound wave to be measured at each position on the preset path at multiple test times.

[0071] This design is based on the fact that the sound pressure of the sound field of the sound wave under test varies periodically. At different times within one cycle of the sound wave under test, the sound pressure at the same location along the preset path may be different. This means that at different times within one cycle of the sound wave under test, the position of the detection beam after penetrating the auxiliary medium may be different, and the illuminance at the initial illumination position may also be different. Therefore, by acquiring the deviation illuminance between the deflection illumination position and the initial illumination position of the detection beam after penetrating the sound field of the sound wave under test at multiple test times within one cycle of the sound wave under test—that is, acquiring multiple deflection illumination positions corresponding to multiple test times and multiple deviation illuminances corresponding to multiple test times within one cycle of the sound wave under test—and then determining the multiple illumination position offsets of the multiple deflection illumination positions relative to the initial illumination position and the multiple illuminance deviations of the multiple deviation illuminances relative to the initial illuminance, that is, determining the illuminance of the multiple deflection illumination positions relative to the initial illumination position, the design aims to determine the illuminance of the multiple deflection illumination positions relative to the initial illumination position. The multiple irradiation position offsets corresponding to the irradiation positions, and the multiple illuminance deviation values ​​corresponding to the multiple deviation illuminance values, that is, the multiple irradiation position offsets corresponding to the multiple test times, and the multiple illuminance deviation values ​​corresponding to the multiple test times, can be used to determine the sound pressure value of the sound field of the sound wave to be tested at each position on the preset path at the multiple test times. In other words, the sound pressure value of the sound field of the sound wave to be tested at each position on the preset path at each test time is determined.

[0072] In one embodiment of the present invention, determining the sound pressure value of the sound field of the sound wave to be measured at each position on the preset path at multiple test times, based on multiple illumination position offsets and multiple illuminance deviation values ​​corresponding one-to-one with multiple test times, may specifically include:

[0073] The measured refractive index of the detection beam at each position along the preset path at multiple test times is determined based on the preset refractive index gradient integral formula, and the sound pressure value is determined based on the measured refractive index. The refractive index gradient integral formula is as follows:

[0074]

[0075] Where a and b are correction coefficients relative to the standard sound wave of the sound wave to be measured, and x is the first direction (e.g., ...). Figures 2-4 The coordinates are shown in the middle direction (x), and the coordinates are shown in the second direction (y). Figures 2-4 The coordinates are shown in the middle direction (y), and the coordinates are shown in the third direction (e.g., z). Figure 2 and Figure 3 The coordinates (as shown in the z-direction) are perpendicular to the first and second directions and lie on the first plane perpendicular to the projection plane of the sound field to be measured. The third direction is perpendicular to the first plane. t is the time of measurement, ΔI is the illuminance deviation value, v is the irradiation position offset, and L is the length of the sound field to be measured in the third direction. This represents the refractive index gradient.

[0076] Specifically, the projection surface of the sound field of the sound wave to be measured is as follows: Figure 2 and Figure 3 If the plane containing the x and z directions is the same, then the first plane perpendicular to the projection plane of the sound field of the sound wave to be measured can be as follows: Figures 2-4 A beam of light emitted along a preset path from the plane containing the x and y directions penetrates the sound field of the sound wave to be measured and can illuminate the first plane. The coordinates of the illumination position of the beam of light on the first plane after penetrating the sound field of the sound wave to be measured at the time of measurement are (x, y, t). Taking the coordinates of the initial illumination position as the origin (0, 0), v(x, y, t) represents the offset of the illumination position on the first plane at the time of measurement, and ΔI(t) represents the illuminance deviation value of the initial illumination position at the time of measurement. The refractive index gradient at the time of measurement can be represented by a third direction parallel to a preset path. The coordinates of a position on the preset path can be represented as (x, y, z). By determining the coordinates z of the third direction, the position on the preset path can be determined. Thus, based on the preset integral relationship of the refractive index gradient, the measured refractive index of the detection beam at each position on the preset path at multiple times of measurement can be determined. Correction coefficients a and b are correction coefficients relative to the standard sound wave of the sound wave to be measured. In practical applications, correction coefficients a and b may be different for sound waves with different powers. Therefore, the sound pressure measurement method provided in this embodiment of the invention can be used to measure the sound pressure of the standard sound wave to obtain the measured value. Then, the measured value can be corrected based on the actual value of the known actual sound pressure of the standard sound wave (e.g., the sound wave emitted by a standard transducer) to determine the correction coefficients a and b, thereby improving the accuracy and range of sound pressure measurement.

[0077] This design works because when no sound wave is applied to the auxiliary medium, the refractive index of the detection beam is the same at different locations within the auxiliary medium as it penetrates the medium. Therefore, the propagation direction of the detection beam does not deflect during this process. However, when the sound wave is applied to the auxiliary medium, the density of the medium varies at different locations due to the sound pressure of the sound field. The refractive index of the detection beam at these locations varies with the density of the auxiliary medium. In other words, the refractive index of the detection beam differs at different locations within the auxiliary medium as it penetrates the medium, causing the propagation direction of the detection beam to deflect due to this difference in refractive index. Furthermore, at different times within one cycle of the sound wave to be measured, the sound pressure at the same location on the preset path may be different. Therefore, the refractive index of the auxiliary medium at the same location on the preset path for the detection beam may be different at different times within one cycle of the sound wave to be measured. Consequently, at different times within one cycle of the sound wave to be measured, the propagation direction of the detection beam may be different, the position irradiated by the detection beam after penetrating the auxiliary medium may be different, and the illuminance of the detection beam at the initial irradiation position after penetrating the auxiliary medium may be different.

[0078] Furthermore, since the irradiation position offset and illuminance deviation are the result of the cumulative change of the detection beam under the influence of the sound pressure of the sound field of the sound wave under test during the process of penetrating the sound field of the sound wave under test, that is, the result of the cumulative change under the influence of the density of the auxiliary medium at each position on the preset path, in other words, the irradiation position offset and illuminance deviation are the result of the cumulative change of the detection beam under the influence of the refractive index of the auxiliary medium at each position on the preset path on the process of penetrating the sound field of the sound wave under test, so that after penetrating the sound field of the sound wave under test, it irradiates at a deflected irradiation position with an irradiation position offset relative to the initial irradiation position, and the illuminance at the initial irradiation position is a deflected illuminance with an illuminance deviation value relative to the initial illuminance, the measured refractive index of the detection beam at each position on the preset path at multiple test times can be determined according to the preset refractive index gradient integral relationship, and the sound pressure value can be determined according to the measured refractive index.

[0079] Optionally, ΔI(t) = (I0 - I(t)) / I0, where I0 is the initial illuminance and I(t) is the deviation illuminance at the time to be measured.

[0080] In one embodiment of the present invention, determining the sound pressure value based on measuring the refractive index may specifically include:

[0081] The sound pressure value is determined based on the measured refractive index and a preset first relationship, which is:

[0082]

[0083] Where n is the measured refractive index, and n0 is the refractive index of the medium to which the sound wave is applied when the sound wave is not applied. ρ is the pressure-light coefficient of the medium to which the sound wave to be measured is loaded, and p is the sound pressure value.

[0084] Specifically, n(x, y, z) represents the measured refractive index at a location on the preset path, and p(x, y, z) represents the sound pressure level at a location on the preset path. In practical applications, the refractive index gradient value at each location on the preset path can be determined by integrating the preset refractive index gradient, thereby determining the measured refractive index n at each location on the preset path. This is because the pressure coefficient of the medium loaded by the sound wave being measured... Since the refractive index n0 of the medium loaded with the sound wave to be measured is known when the sound wave to be measured is not loaded, the sound pressure value p at each position on the preset path can be determined according to the first relationship.

[0085] like Figure 4 and Figure 5 As shown, in one embodiment of the present invention, the detection beam can be a Gaussian beam.

[0086] like Figure 4 and Figure 5 As shown, in one embodiment of the present invention, the initial illumination position and the deflection illumination position of the Gaussian beam are both the peak illumination positions of the Gaussian beam.

[0087] In other words, in practical applications, when the sound wave to be measured is not loaded, the location of the peak illuminance at the point of illumination by the Gaussian beam can be considered the initial illumination position, and the peak illuminance at the point of illumination by the Gaussian beam can be considered the initial illuminance. When the sound wave to be measured is loaded, and the propagation direction of the Gaussian beam is deflected, the location of the peak illuminance at the point of illumination by the Gaussian beam changes. The location of the peak illuminance at the point of illumination by the Gaussian beam may no longer be at the initial illumination position, while the non-illuminance peak may be at the initial illumination position. In this case, the location of the peak illuminance at the point of illumination by the Gaussian beam can be considered the deflected illumination position, and the non-illuminance peak of the Gaussian beam at the initial illumination position can be considered the deflected illuminance.

[0088] In one embodiment of the present invention, the sound pressure measurement method may further include the following steps:

[0089] A three-dimensional matrix is ​​set for the sound field of the sound wave to be measured, and the sound pressure value of each element of the three-dimensional matrix is ​​determined.

[0090] This design is based on the fact that the sound field of the sound wave to be measured is distributed in a three-dimensional space. By setting a three-dimensional matrix for the sound field of the sound wave to be measured and determining the sound pressure value of each element of the three-dimensional matrix, the distribution of the sound field of the sound wave to be measured in its distributed three-dimensional space can be determined. Furthermore, it can avoid the diffraction superposition problem caused by measuring sound pressure in two-dimensional space, thereby improving the accuracy, measurement range and spatial resolution of sound pressure measurement, and thus meeting the measurement requirements of HIFU sound field sound pressure.

[0091] In practical applications, a three-dimensional matrix is ​​set for the sound field of the sound wave to be measured. That is, the three-dimensional space of the sound field distribution of the sound wave to be measured is divided into grids. The smallest grid size that can be divided is the minimum measurement accuracy. The smaller the measurement accuracy, the higher the measurement accuracy and the higher the spatial resolution.

[0092] In one embodiment of the present invention, setting a three-dimensional matrix for the sound field of the sound wave to be measured and determining the sound pressure value of each element of the three-dimensional matrix may specifically include:

[0093] Detection beams are emitted along multiple preset paths in the three-dimensional direction of the three-dimensional matrix;

[0094] Determine the sound pressure value at each position corresponding to each element of a three-dimensional matrix on multiple preset paths.

[0095] In practical applications, detection beams are emitted along multiple preset paths in the three-dimensional direction of a three-dimensional matrix. Since a detection beam emitted along a preset path can penetrate multiple elements in one dimension of the three-dimensional matrix, the sound pressure value at each position on a preset path can represent the sound pressure value of each element in one dimension of the corresponding three-dimensional matrix. Thus, by determining the sound pressure value at each position corresponding to each element of the three-dimensional matrix on multiple preset paths, the sound pressure value of each element in the three-dimensional direction of the three-dimensional matrix can be determined, thereby determining the sound pressure value of each element of the three-dimensional matrix.

[0096] In one embodiment of the present invention, emitting detection beams along multiple preset paths in the three-dimensional direction of a three-dimensional matrix may specifically include:

[0097] Define a first plane perpendicular to the projection surface of the sound field of the sound wave to be measured;

[0098] The sound wave to be measured completes one rotation by rotating multiple times.

[0099] Between two adjacent rotations of the sound wave under test and after one rotation, a detection beam is emitted along a preset path perpendicular to the first plane, and the detection beam scans the first plane.

[0100] For example, when the sound wave to be measured is not rotating, its rotation angle is 0°. At this time, it can first be along the first plane (optional, such as...).Figures 3-5 A detection beam is emitted along a preset path perpendicular to the plane containing the x and y directions. The detection beam scans the first plane for the first time. The detection beam emitted along a preset path perpendicular to the first plane can penetrate multiple elements in one dimension of the three-dimensional matrix corresponding to the preset path. By scanning the first plane, the projection distribution of the sound pressure gradient of the sound field of the sound wave under test on the first plane can be determined, that is, the projection distribution of the refractive index gradient of the auxiliary medium on the first plane can be determined. Then, the sound wave to be tested can be rotated, for example, by 0.01°-1°, and a detection beam is emitted a second time along a preset path perpendicular to the first plane. The detection beam is then scanned across the first plane a second time until the sound wave to be tested has rotated 360°. Finally, a detection beam is emitted a last time along a preset path perpendicular to the first plane, and the detection beam is scanned across the first plane a last time. In this way, the projection distribution of the sound pressure gradient of the sound field of the sound wave to be tested on the first plane when the sound wave to be tested rotates to different angles can be determined. Afterward, the projection distribution of the sound pressure gradient of the sound field of the sound wave to be tested on the first plane when the sound wave to be tested rotates to different angles can be calculated using a tomographic reconstruction algorithm, thereby determining the sound pressure value of each element of the three-dimensional matrix.

[0101] In one embodiment of the present invention, emitting a detection beam along a preset path perpendicular to the first plane and scanning the first plane with the detection beam can specifically include:

[0102] Multiple path groups are set, and each path group includes multiple preset paths. The multiple preset paths of the same path group are distributed at intervals in a first direction perpendicular to the projection plane of the sound field of the sound wave to be measured on the first plane. Different path groups are distributed at intervals in a second direction perpendicular to the first direction on the first plane.

[0103] The detection beams are emitted sequentially according to the order of multiple path groups.

[0104] In practical applications, taking the plane containing directions x and y in the figure as the first plane as an example, multiple preset paths of the same path group can be distributed at intervals in direction x (i.e., the first direction), and different path groups can be distributed at intervals in direction y (i.e., the second direction). In the process of making the detection beam scan the first plane, the detection beam can be emitted along multiple preset paths in one path group first. That is, the detection beam is emitted along multiple preset paths spaced apart in direction x first, that is, the detection beam is scanned along direction x first. Then, the detection beam is emitted along multiple preset paths in another adjacent path group. That is, the detection beam is emitted along multiple preset paths spaced apart in direction y again, that is, the detection beam is scanned along direction y again, so that the detection beam scans the plane containing directions x and y (i.e., the first plane).

[0105] like Figure 2As shown, this embodiment of the invention also provides a sound pressure measuring device for performing the sound pressure measuring method provided in this embodiment of the invention. The sound pressure measuring device includes a light source 1, a collection component 2, and a controller 3. The light source 1 is used to emit a detection beam, the collection component 2 is used to acquire the detection beam, and the controller 3 is signal-connected to the light source 1 and the collection component 2 respectively, and is used to control the start and stop of the light source 1 and the acquisition of the detection beam by the collection component 2.

[0106] The sound pressure measurement device provided in this embodiment of the invention can improve the accuracy, measurement range and spatial resolution of sound pressure measurement by executing the sound pressure measurement method provided in this embodiment of the invention, thereby meeting the sound pressure measurement requirements of HIFU sound field.

[0107] Optionally, light source 1 may include a laser.

[0108] Optionally, the laser can be a continuous laser capable of continuously emitting laser beams.

[0109] Optionally, the acquisition component 2 may include an enhanced charge-coupled device (ICCD) camera.

[0110] In practical applications, ICCD cameras have very short shutter speeds, allowing for precise control of the shooting time and shutter size (with nanosecond-level accuracy) via signal triggering, enabling instantaneous acquisition of the detection beam. When no sound wave to be measured is applied, the detection beam illuminates the center of the ICCD camera, i.e., the origin position. When the sound wave to be measured is applied, the illumination position and illuminance distribution of the detection beam change with the period of the sound wave (i.e., the illumination position offset and illuminance deviation). By controlling the shooting time and shutter size of the ICCD camera, the change process of the detection beam with the period of the sound wave to be measured can be acquired, thereby determining the sound pressure distribution of the ultrasound field under test.

[0111] like Figure 2 As shown, in one embodiment of the present invention, the sound pressure measuring device may further include a first moving component 4, a second moving component 5, and a rotating component 6. The first moving component 4 is connected to the light source 1 and is used to drive the light source 1 to move in a first direction and a second direction. The first direction and the second direction are perpendicular and are located on a first plane perpendicular to the projection surface of the sound field of the sound wave to be measured. The second moving component 5 is connected to the acquisition component 2 and moves synchronously with the first moving component 4, and is used to drive the acquisition component 2 to move synchronously with the light source 1. The rotating component 6 is connected to the sound source 10 that provides the sound wave to be measured and is used to drive the sound source 10 to rotate.

[0112] The first moving component 4 moves the light source 1 in the first and second directions, allowing the detection beam to scan the first plane. The second moving component 5 moves the acquisition component 2 synchronously with the light source 1, ensuring that the relative position of the light source 1 and the acquisition component 2 remains constant as the light source 1 moves in the first and second directions. This keeps the position of the detection beam on the acquisition component 2 constant, ensuring that the detection beam always penetrates the auxiliary medium and illuminates the initial illumination position when no sound wave is loaded, thus ensuring accurate determination of the illumination position offset and illuminance deviation. The rotating component 6 rotates the sound source 10, allowing the sound wave to be measured to rotate.

[0113] Optionally, the sound source 10 may include a HIFU transducer.

[0114] like Figure 2 As shown, optionally, the first moving part 4 may include a first moving platform, and the light source 1 may be disposed above the first moving platform.

[0115] Optionally, the distance by which the first moving component 4 moves the light source 1 in the first and second directions can be equal to the diameter of the detection beam and less than or equal to half the wavelength of the sound wave to be measured.

[0116] Optionally, the first moving component 4 can move the light source 1 in the first and second directions with a moving accuracy of 0.01mm-0.05mm.

[0117] like Figure 2 As shown, optionally, the second moving component 5 may include a second moving platform, and the acquisition component 2 may be positioned above the second moving platform.

[0118] Optionally, the distance by which the second moving part 5 moves the light source 1 in the first and second directions can be equal to the diameter of the detection beam and less than or equal to half the wavelength of the sound wave to be measured.

[0119] Optionally, the second moving part 5 can drive the acquisition part 2 to move in the first and second directions with a moving accuracy of 0.01mm-0.05mm.

[0120] like Figure 2 As shown, optionally, the rotating component 6 may include a rotating platform, and the sound source 10 may be located below the rotating platform.

[0121] Optionally, the rotational accuracy of the rotating component 6 driving the sound source 10 to rotate can be ±30".

[0122] like Figure 2As shown, optionally, the controller 3 is connected to the first moving part 4, the second moving part 5 and the rotating part 6 by signal, and is used to control the first moving part 4 to move, control the second moving part 5 to move, and control the rotating part 6 to rotate by signal.

[0123] In one embodiment of the present invention, the rate of change of the output power of the light source 1 may be less than or equal to 1%.

[0124] This design is based on the fact that the lower the rate of change of the output power of light source 1, the better the stability of the output power of light source 1. Since the output power of light source 1 affects the illuminance of the detection beam, the better the stability of the output power of light source 1, the more accurate and stable the obtained illuminance deviation value will be, thereby improving the accuracy of sound pressure measurement.

[0125] like Figure 2 As shown, optionally, the sound pressure measurement device may also include a signal generator 7 and a power amplifier 8. The controller 3, the signal generator 7, the power amplifier 8 and the sound source 10 are connected in sequence. The controller 3 is used to send a control signal to the signal generator 7, so that the signal generator 7 sends a control signal to the power amplifier 8, thereby controlling the output power of the sound source 10 through the power amplifier 8.

[0126] like Figure 2 As shown, optionally, the sound pressure measurement device may also include a computer 9. The computer 9 may be equipped with a processing module and a computer 9 readable storage medium. The processing module is connected to the controller 3 and the acquisition component 2 by signals. The computer 9 readable storage medium stores the computer 9 program. When the computer 9 program is executed by the processing module, it can realize the sound pressure measurement method provided in the embodiment of the present invention.

[0127] like Figure 2 As shown, optionally, the sound pressure measuring device may also include a holding component 11 for holding an auxiliary medium.

[0128] For example, taking water as the auxiliary medium, the holding component 11 may include a water tank. In practical applications, the viewing window of the water tank can allow the detection beam to pass through. The viewing window needs to have good optical uniformity to avoid uneven deflection of the detection beam when it passes through the viewing window. In this case, the projection surface of the sound field of the sound wave to be measured can be, for example, the projection surface of the holding component 11 of the water tank, such as the orthographic projection surface of the water tank.

[0129] like Figure 2 As shown, optionally, the sound pressure measuring device may also include a beam adjustment component 12. The light source 1, the beam adjustment component 12 and the holding component 11 are arranged in sequence. The beam adjustment component 12 can adjust the diameter of the detection beam passing through it.

[0130] like Figure 2 Figure 2As shown, optionally, the beam adjustment assembly 12 may include a focusing lens 121, a pinhole filter 122, a collimating lens 123 and a grating (not shown in the figure), and the light source 1, focusing lens 121, pinhole filter 122, collimating lens 123, grating and holding component 11 are arranged in sequence.

[0131] This invention also provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processing module, it can implement the sound pressure measurement method provided in this invention.

[0132] The computer 9 readable storage medium provided in this embodiment of the invention stores a computer 9 program that, when executed by a processing module, can implement the sound pressure measurement method provided in this embodiment of the invention, thereby improving the accuracy, measurement range, and spatial resolution of sound pressure measurement, and thus meeting the sound pressure measurement requirements of HIFU sound field.

[0133] In summary, the sound pressure measurement method, sound pressure measurement device, and computer-readable storage medium provided in the embodiments of the present invention can improve the accuracy, measurement range, and spatial resolution of sound pressure measurement, thereby meeting the measurement requirements of HIFU sound field sound pressure.

[0134] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for measuring sound pressure, characterized in that, Includes the following steps: Emit a detection beam along a preset path; When the sound wave to be tested is not loaded, the initial irradiation position of the detection beam and the initial illuminance of the initial irradiation position are obtained; When loading the sound wave to be tested, the deviation illuminance of the detection beam at the deflection irradiation position after penetrating the sound field of the sound wave to be tested and the initial irradiation position is obtained. The illumination position offset of the deflected illumination position relative to the initial illumination position and the illuminance deviation value of the deflected illuminance relative to the initial illuminance are determined. Based on the illumination position offset and the illuminance deviation value, the sound pressure value of the sound field of the sound wave to be measured at each position on the preset path is determined.

2. The sound pressure measurement method according to claim 1, characterized in that, The specific steps of obtaining the deviation illuminance between the deflected illumination position of the detection beam after penetrating the sound field of the sound wave to be measured and the initial illumination position include: The deflection illumination position after the detection beam penetrates the sound field of the sound wave under test and the deviation illuminance at the initial illumination position are obtained at multiple test times within one cycle of the sound wave under test. The step of determining the irradiation position offset of the deflected irradiation position relative to the initial irradiation position and the irradiation deviation value of the deflected illuminance relative to the initial illuminance, and determining the sound pressure value of the sound field of the sound wave to be measured at each position on the preset path based on the irradiation position offset and the irradiation deviation value specifically includes: Determine multiple irradiation position offsets relative to the initial irradiation position and multiple illuminance deviations relative to the initial illuminance. Based on multiple irradiation position offsets and multiple illuminance deviations that correspond one-to-one with multiple test times, determine the sound pressure value of the sound field to be measured at each position on the preset path at multiple test times.

3. The sound pressure measurement method according to claim 2, characterized in that, The step of determining the sound pressure value of the sound wave field to be measured at each position on the preset path at multiple test times based on multiple illumination position offsets and multiple illuminance deviation values ​​corresponding one-to-one with multiple test times specifically includes: The measured refractive index of the detection beam at each position on the preset path at multiple measured times is determined according to a preset refractive index gradient integral formula, and the sound pressure value is determined according to the measured refractive index. The refractive index gradient integral formula is: Where a and b are correction coefficients relative to the standard sound wave of the sound wave to be measured, x is the coordinate in the first direction, y is the coordinate in the second direction, z is the coordinate in the third direction, the first direction and the second direction are perpendicular and lie on a first plane perpendicular to the projection plane of the sound field of the sound wave to be measured, the third direction is perpendicular to the first plane, t is the time of measurement, ΔI is the illuminance deviation value, v is the irradiation position offset, and L is the length of the sound field of the sound wave to be measured in the third direction. The refractive index gradient is given.

4. The sound pressure measurement method according to claim 3, characterized in that, The step of determining the sound pressure value based on the measured refractive index specifically includes: The sound pressure value is determined based on the measured refractive index and a preset first relationship, wherein the first relationship is: Wherein, n is the measured refractive index, and n0 is the refractive index of the medium to which the sound wave is loaded when the sound wave is not loaded. ρ is the pressure-light coefficient of the medium to which the sound wave under test is loaded, and p is the sound pressure value.

5. The sound pressure measurement method according to claim 1, characterized in that, The detection beam is a Gaussian beam.

6. The sound pressure measurement method according to claim 5, characterized in that, The initial illumination position and the deflection illumination position of the Gaussian beam are both the peak illuminance positions of the Gaussian beam.

7. The sound pressure measurement method according to claim 1, characterized in that, The sound pressure measurement method further includes the following steps: A three-dimensional matrix is ​​set for the sound field of the sound wave to be measured, and the sound pressure value of each element of the three-dimensional matrix is ​​determined.

8. The sound pressure measurement method according to claim 7, characterized in that, The step of setting a three-dimensional matrix for the sound field of the sound wave to be measured and determining the sound pressure value of each element of the three-dimensional matrix specifically includes: The detection beam is emitted along multiple preset paths in the three-dimensional direction of the three-dimensional matrix; Determine the sound pressure value at each position on multiple preset paths corresponding to each element of the three-dimensional matrix.

9. The sound pressure measurement method according to claim 8, characterized in that, The emission of the detection beam along multiple preset paths in the three-dimensional direction of the three-dimensional matrix specifically includes: Define a first plane perpendicular to the projection surface of the sound field of the sound wave to be measured; The sound wave to be measured completes one rotation by rotating multiple times. Between two adjacent rotations of the sound wave under test and after one rotation, the detection beam is emitted along a preset path perpendicular to the first plane, and the detection beam scans the first plane.

10. The sound pressure measurement method according to claim 9, characterized in that, The step of emitting the detection beam along a preset path perpendicular to the first plane and scanning the first plane specifically includes: Multiple path groups are set, and each path group includes multiple preset paths. The multiple preset paths of the same path group are distributed at intervals in a first direction parallel to the projection plane of the sound field of the sound wave to be measured on the first plane. Different path groups are distributed at intervals in a second direction perpendicular to the first direction on the first plane. The detection beams are emitted sequentially according to the order of the multiple path groups.

11. A sound pressure measuring device, characterized in that, For performing the sound pressure measurement method as described in any one of claims 1-10, the sound pressure measurement device includes a light source, a data acquisition component, and a controller. The light source is used to emit the detection beam, the data acquisition component is used to acquire the detection beam, and the controller is signal-connected to the light source and the data acquisition component, respectively, for controlling the start and stop of the light source and the acquisition of the detection beam by the data acquisition component.

12. The sound pressure measuring device according to claim 11, characterized in that, The sound pressure measuring device further includes a first moving component, a second moving component, and a rotating component. The first moving component is connected to the light source and is used to drive the light source to move in a first direction and a second direction. The first direction and the second direction are perpendicular and located on a first plane perpendicular to the projection surface of the sound field of the sound wave to be measured. The second moving component is connected to the acquisition component and moves synchronously with the first moving component, and is used to drive the acquisition component to move synchronously with the light source. The rotating component is connected to the sound source that provides the sound wave to be measured and is used to drive the sound source to rotate.

13. The sound pressure measuring device according to claim 11, characterized in that, The rate of change of the output power of the light source is less than or equal to 1%.

14. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by the processing module, enables the implementation of the sound pressure measurement method as described in any one of claims 1-10.

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