An adaptive photoacoustic microscopic imaging method, device and equipment

Abstract

The application relates to the technical field of photoacoustic microscopic imaging, and discloses a self-adaptive photoacoustic microscopic imaging method, device and equipment. The method is applied to a self-adaptive photoacoustic microscopic imaging device, and the device comprises an initial photoacoustic microscopic imaging component, a continuous wave laser and a spatial light modulator. The method comprises the following steps: controlling the initial photoacoustic microscopic imaging component to emit first pulsed laser and second pulsed laser, and controlling the continuous wave laser to emit continuous wave laser; and controlling the spatial light modulator to perform wavefront modulation on the first pulsed laser, the second pulsed laser and the continuous wave laser; wherein when performing the wavefront modulation, the spatial light modulator takes a differential photoacoustic signal as feedback. The application uses a greedy algorithm to optimize a phase diagram displayed on an SLM, and dynamically compensates aberration caused by an absorber point by point through a GR effect, so that microstructures that cannot be distinguished by a traditional PAM are revealed, and the compensation of the aberration can effectively improve signal strength and lateral resolution.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photoacoustic microscopy, in particular to an adaptive photoacoustic microscopy method, device and equipment. BACKGROUND

[0002] Photoacoustic microscopy (PAM) uses non-ionizing photons and low-scattering ultrasonic waves to image an absorber, and all absorbers have the property of absorbing light, so PAM has been widely used. PAM combines the principles of optical excitation and acoustic detection: when a pulsed focused light beam excites an absorber, the absorber generates ultrasonic waves due to heat absorption, and can achieve a transverse resolution as low as the optical diffraction limit of sub-micron. This mode is called optical-resolution photoacoustic microscopy (OR-PAM). However, the absorber is essentially inhomogeneous, which distorts the optical wavefront and induces optical aberrations during light propagation. Therefore, the imaging quality will decrease with the increase of imaging depth. SUMMARY

[0003] Therefore, the present application provides an adaptive photoacoustic microscopy method, device and equipment to solve the problem that the optical aberrations induced during light propagation in the process of photoacoustic microscopy, thereby causing the imaging quality to decrease with the increase of imaging depth.

[0004] In a first aspect, the present application provides an adaptive photoacoustic microscopy method applied to an adaptive photoacoustic microscopy device, wherein the device comprises an initial photoacoustic microscopy component, a continuous wave laser and a spatial light modulator; the method comprises: controlling the initial photoacoustic microscopy component to emit first pulsed laser and second pulsed laser, and controlling the continuous wave laser to emit continuous wave laser; controlling the spatial light modulator to modulate the wavefront of the first pulsed laser, the second pulsed laser and the continuous wave laser; wherein the spatial light modulator modulates the wavefront according to the differential photoacoustic signal as feedback.

[0005] In a second aspect, the present application provides an adaptive photoacoustic microscopic imaging device, comprising: an initial photoacoustic microscopic imaging component, a continuous wave laser, and a spatial light modulator; wherein the initial photoacoustic microscopic imaging component is configured to acquire an image of a target to be imaged based on a first pulsed laser and a second pulsed laser; the continuous wave laser is configured to emit a continuous wave laser to the target to be imaged during the imaging process of the initial photoacoustic microscopic imaging component to generate a GR effect; and the spatial light modulator is configured to modulate wavefronts of the first pulsed laser, the second pulsed laser, and the continuous wave laser; wherein the spatial light modulator modulates wavefronts based on a differential photoacoustic signal as feedback.

[0006] In an optional embodiment, the differential photoacoustic signal is acquired based on the following steps:

[0007] Acquiring photoacoustic amplitudes of the first pulsed laser and the second pulsed laser under a preset condition; wherein the preset condition is that the light flux is subject to a two-dimensional Gaussian distribution in the lateral direction;

[0008] Based on the photoacoustic amplitudes of the first pulsed laser and the second pulsed laser under the preset condition, a differential photoacoustic signal between the first pulsed laser and the second pulsed laser is obtained.

[0009] In an optional embodiment, the initial photoacoustic microscopic imaging component comprises: a laser emitter, a laser focusing tool, an ultrasonic transducer, and a data processing device.

[0010] In an optional embodiment, the spatial light modulator is configured to perform the following steps to modulate wavefronts of the first pulsed laser, the second pulsed laser, and the continuous wave laser:

[0011] Acquiring a plurality of ordered Zernike polynomials; wherein the Zernike polynomials are used to describe optical aberrations generated by the initial photoacoustic microscopic imaging component;

[0012] Loading the plurality of ordered Zernike polynomials into the spatial light modulator in order, and determining coefficients corresponding to the plurality of ordered Zernike polynomials; wherein during the determination of the coefficients corresponding to the plurality of ordered Zernike polynomials, the differential photoacoustic signal becomes larger;

[0013] Modulating wavefronts of the first pulsed laser, the second pulsed laser, and the continuous wave laser based on the coefficients corresponding to the plurality of ordered Zernike polynomials.

[0014] In an optional embodiment, loading the plurality of ordered Zernike polynomials into the spatial light modulator in order, and determining coefficients corresponding to the plurality of ordered Zernike polynomials, comprises:

[0015] constructing a feedback loop between the spatial light modulator and the ultrasonic transducer and the data processing device in the initial photoacoustic microscopic imaging assembly;

[0016] According to the feedback loop, a plurality of ordered Zernike polynomials are traversed to determine the coefficients corresponding to the plurality of ordered Zernike polynomials.

[0017] In an optional embodiment, the spatial light modulator is a reflective liquid crystal spatial light modulator.

[0018] In an optional embodiment, the center frequency of the ultrasonic transducer is 50 MHz, and the bandwidth is 31.40-73.25 MHz.

[0019] In an optional embodiment, the order of the Zernike polynomials is 4-10.

[0020] In a third aspect, the present application provides a computer device, comprising: a memory and a processor, which are in communication connection with each other, and the memory stores computer instructions, and the processor executes the computer instructions to implement the adaptive photoacoustic microscopic imaging method according to the first aspect or any one of the corresponding embodiments thereof.

[0021] The present application has the following beneficial effects:

[0022] Compared with other 3D optical microscopic techniques assisted by AO, the adaptive photoacoustic microscopic imaging method provided by the present application uses an adaptive photoacoustic microscopic imaging device (AWA-GR-PAM) to consider defocus correction, uses an intensity-modulated continuous-wave (CW) laser for heating an absorber to generate a GR effect, and can realize more tightly focused light beams. Then, an acoustic differential signal instead of an optical signal is used to indirectly determine an optimized wave front. The present application uses a greedy algorithm to optimize a phase pattern displayed on a spatial light modulator (SLM), and dynamically compensates for aberrations caused by the absorber point by point through the GR effect, reveals microstructures that cannot be distinguished by a conventional PAM, and compensates for aberrations, which can effectively improve signal strength and lateral resolution. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0024] Figure 1is a flow chart of a photoacoustic microscopic imaging method according to an embodiment of the present application;

[0025] Figure 2 is a schematic diagram of the working principle of a photoacoustic microscopic imaging device (AWA-GR-PAM) according to an embodiment of the present application;

[0026] Figure 3 is a schematic diagram of the structure of a photoacoustic microscopic imaging device (AWA-GR-PAM) according to an embodiment of the present application;

[0027] Figure 4 is a timing diagram of a laser emitter, a continuous wave laser and a photoacoustic signal in an initial photoacoustic microscopic imaging assembly according to an embodiment of the present application;

[0028] Figure 5 is a 2D MAP image of a carbon fiber filament after AWA-GR correction according to an embodiment of the present application;

[0029] Figure 6 is a 2D MAP image of a carbon fiber filament without AWA-GR correction according to an embodiment of the present application;

[0030] Figure 7 is a normalized intensity distribution chart of a carbon fiber filament after AWA-GR correction and without AWA-GR correction according to an embodiment of the present application;

[0031] Figure 8 is Figure 3 the phase diagram in the solid line box position;

[0032] Figure 9 is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0034] Photoacoustic microscopy (PAM) uses non-ionizing photons and low-scattering ultrasonic waves to image absorbers, and all absorbers have the property of absorbing light, so PAM has been widely used. PAM combines the principles of optical excitation and acoustic detection: when a pulsed focused light beam excites an absorber, the absorber generates ultrasonic waves due to heat absorption, enabling a transverse resolution as low as the optical diffraction limit of sub-micron, which is called optical-resolution photoacoustic microscopy (OR-PAM). However, the absorber is essentially inhomogeneous, which distorts the optical wavefront and induces optical aberrations during light propagation. Therefore, the imaging quality decreases with the increase of the imaging depth.

[0035] Therefore, the application provides an adaptive photoacoustic microscopy method, device and equipment, as shown in the following. Figure 1 As shown in the following, the application provides a photoacoustic microscopy method, and the specific process is as follows.

[0036] Step S1: control the initial photoacoustic microscopy assembly to emit first pulsed laser and second pulsed laser, and control the continuous wave laser to emit continuous wave laser.

[0037] Step S2: control the spatial light modulator to perform wavefront modulation on the first pulsed laser, the second pulsed laser and the continuous wave laser; wherein the spatial light modulator performs wavefront modulation according to the differential photoacoustic signal as feedback.

[0038] The adaptive photoacoustic microscopy method is applied to an adaptive photoacoustic microscopy device, and the device comprises an initial photoacoustic microscopy assembly, a continuous wave laser and a spatial light modulator, as shown in the following. Figures 2-4 As shown in the following, the application provides an adaptive photoacoustic microscopy device. The device comprises an initial photoacoustic microscopy assembly, a continuous wave laser and a spatial light modulator.

[0039] The adaptive photoacoustic microscopy device provided by the application is an adaptive photoacoustic microscopy device combined with Grueneisen relaxation and acoustic feedback wavefront (AWA-GR-PAM). The device comprises an initial photoacoustic microscopy assembly, a continuous wave laser and a spatial light modulator.

[0040] The initial photoacoustic microscopy assembly is used to obtain an image of the target to be imaged according to the first pulsed laser and the second pulsed laser.

[0041] Specifically, the initial photoacoustic microscopy assembly comprises a laser emitter, a laser focusing tool, an ultrasonic transducer and a data processing device.

[0042] The bandwidth of the ultrasonic transducer is 31.40-73.25 MHz, and the center frequency is 50 MHz.

[0043] The continuous wave laser is used to emit continuous wave laser to the target to be imaged in the imaging process of the initial photoacoustic microscopic imaging assembly to generate the GR effect.

[0044] Specifically, the intensity-modulated continuous-wave (CW) laser is used to heat the absorber to generate the GR effect, which can achieve more tightly focused beams.

[0045] The GR effect, also known as the Grueneisen relaxation, is a nonlinear phenomenon in photoacoustic effect. In traditional photoacoustic imaging, the signal amplitude is linearly related to the absorption coefficient. However, in the GR effect, this relationship becomes quadratic nonlinearity, i.e., the signal amplitude is proportional to the square of the absorption coefficient. This nonlinear relationship provides a new perspective and application for photoacoustic imaging.

[0046] In this application, the GR effect describes the change in the Grueneisen parameter caused by the heating of the absorber by the first pulsed laser and the second pulsed laser.

[0047] The spatial light modulator is used to modulate the wavefront of the first pulsed laser, the second pulsed laser, and the continuous wave laser. When modulating the wavefront, the spatial light modulator uses the differential photoacoustic signal as feedback.

[0048] The differential photoacoustic signal is obtained according to the following steps:

[0049] Step a1: Obtain the photoacoustic amplitude of the first pulsed laser and the second pulsed laser under a preset condition. The preset condition is that the optical flux follows a two-dimensional Gaussian distribution in the lateral direction.

[0050] Step a2: Obtain the differential photoacoustic signal between the first pulsed laser and the second pulsed laser based on the photoacoustic amplitude of the first pulsed laser and the second pulsed laser under the preset condition.

[0051] In this embodiment, as the temperature increases, the Grueneisen parameter increases, resulting in a stronger photoacoustic signal. Specifically, two identical nanosecond laser pulses (the first pulsed laser and the second pulsed laser) sequentially excite the absorber (the target to be imaged) with a sub-microsecond delay. The initial voltage rise generated by the first pulsed laser can be represented as:

[0052] p1=Γ0η th μ a F (1)

[0053] Where Γ0 is the Grueneisen parameter at the initial temperature, η this the thermal conversion efficiency, μ a is the light absorption coefficient, F is the light flux. Within the thermal relaxation time of the first laser pulse, the second laser pulse excites the same absorber, which produces another initial pressure rise:

[0054] p2=(Γ0+Gη th μ a F)η th μ a F (2)

[0055] Wherein, G is the coefficient of the change of the Grueneisen parameter and the energy absorbed by the first laser pulse. Assuming that the light flux obeys two-dimensional Gaussian distribution in the transverse direction, the photoacoustic amplitude generated by the first laser pulse can be expressed as:

[0056]

[0057] Wherein, k is a constant related to the detection sensitivity of the photoacoustic signal, E is the pulse energy, and w is the waist of the Gaussian beam; x, y are transverse coordinates; Similarly, the photoacoustic amplitude generated by the second laser pulse can be expressed as:

[0058]

[0059] Difference operation is performed on equations (3) and (4) to obtain the differential photoacoustic signal:

[0060]

[0061] It can be seen from equations (3) and (5) that the resolution of imaging using the GR effect is higher than that of the traditional PAM by √2, and the focusing of the light beam can be more closely. The application uses an intensity-modulated CW laser to heat the absorber, which is convenient for cost saving.

[0062] Further, the spatial light modulator is used to perform the following steps to modulate the wavefront of the first pulsed laser, the second pulsed laser and the continuous wave laser:

[0063] Step b1, obtaining a plurality of ordered Zernike polynomials; wherein the Zernike polynomials are used to describe the optical aberration generated by the initial photoacoustic microscopic imaging assembly.

[0064] Step b2, loading a plurality of ordered Zernike polynomials into the spatial light modulator in order, and determining the coefficients corresponding to the plurality of ordered Zernike polynomials; wherein the differential photoacoustic signal becomes larger in the process of determining the coefficients corresponding to the plurality of ordered Zernike polynomials.

[0065] Here, a series of ordered Zernike polynomials are loaded into a spatial light modulator SLM in order. These Zernike polynomials are orthogonal to each other within a circular pupil, and each polynomial represents an optical aberration.

[0066] Step b3, wavefront modulation of the first pulsed laser, the second pulsed laser and the continuous wave laser according to the coefficients corresponding to the series of ordered Zernike polynomials.

[0067] Wherein, a series of ordered Zernike polynomials are loaded into a spatial light modulator in order, and the coefficients corresponding to the series of ordered Zernike polynomials are determined, comprising:

[0068] First, a feedback loop is constructed between the spatial light modulator and the ultrasonic transducer and data processing device in the initial photoacoustic microscopic imaging assembly. Then, according to the feedback loop, the series of ordered Zernike polynomials are traversed to determine the coefficients corresponding to the series of ordered Zernike polynomials.

[0069] By constructing a feedback loop between the spatial light modulator and the ultrasonic transducer and data processing device in the initial photoacoustic microscopic imaging assembly, the coefficients of the Zernike polynomials of each order are traversed and determined. The feedback loop ensures that the differential photoacoustic signal ΔPA(x,y) is continuously enhanced after each order of aberration is corrected. Since ΔPA(x,y) does not include the unmarked photoacoustic signal, it is proportional to E 2 Therefore, the AWA-GR-PAM can effectively compensate for optical aberrations of large features and small features at the same time. The AWA-GR-PAM does not require optical wavefront sensing to determine optical aberrations, and is particularly suitable for PAM for ultrasonic detection. At the same time, the Zernike polynomials can well represent the optical aberrations, so the feedback process is very effective, and in this application, only low-order Zernike polynomials are needed to solve the problem of optical aberrations.

[0070] It should be noted that the working principle of the AWA-GR-PAM provided by the present application is as shown in Figure 2 The initial photoacoustic microscopic imaging assembly emits a first pulsed laser to generate a reference photoacoustic signal. After being heated by the continuous wave laser emitted by the continuous wave laser, a second pulsed laser is triggered to generate a photoacoustic signal with a larger amplitude. The spatial light modulator SLM modulates the wavefront of the first pulsed laser, the second pulsed laser and the continuous wave laser to compensate for the aberrations caused by the absorber. The phase pattern displayed by the spatial light modulator SLM is the inverse of the distorted wavefront, thereby eliminating distortion and generating a high-quality focus in the deep. In order to obtain the optimal phase pattern, a feedback loop is established between the spatial light modulator SLM, the ultrasonic transducer and the computer to optimize the differential photoacoustic signal amplitude, wherein ΔPA N >…>ΔPA2>ΔPA1.

[0071] The following is based on Figures 3-4 The photoacoustic microscopic imaging device provided by the present application is described below in terms of a specific device embodiment.

[0072] As shown in Figure 3 , the photoacoustic microscopic imaging device comprises a 532 nm nanosecond pulsed laser (laser emitter in the initial photoacoustic microscopic imaging assembly) and a 532 nm CW laser (continuous wave laser), wherein the pulsed laser has a large pulse-to-pulse intensity fluctuation, which can affect the feedback signal. In this embodiment, a photodiode is used to monitor the intensity of the light reflected by the beam splitter, and the measured value is used for normalization. Then, the combination of the half-wave plate and the polarization beam splitter sets the combined light (first pulsed laser, second pulsed laser and continuous wave laser) to horizontal polarization, the combined light is expanded by the lens group with a focal length of 25 mm and 125 mm, and is spatially filtered by the pinhole located in the focal plane. Then, a reflective liquid crystal SLM is used for wavefront modulation, and the combined light is focused to the absorber after being reflected by the SLM. In this embodiment, the numerical aperture (NA) of the AWA-GR-PAM is 0.1. After the light is absorbed by the absorber, the photoacoustic signal is captured by the ultrasonic transducer with a center frequency of 50 MHz, and is collected by the data acquisition card after amplification. The sample is two-dimensionally scanned using the motorized displacement stage. Figure 3 The time sequence of the pulsed laser (laser emitter in the initial photoacoustic microscopic imaging assembly), the CW laser (continuous wave laser) and the photoacoustic signal is shown. The pulsed laser (laser emitter in the initial photoacoustic microscopic imaging assembly) generates a double-pulse sequence with a repetition frequency of 1 kHz. In each sequence, the first pulsed laser is triggered to generate a reference photoacoustic signal before the CW laser (continuous wave laser) heating, as PA1 and PA3 in Figure 4 . The second pulsed laser is triggered at the end of the CW laser (continuous wave laser) heating to generate a photoacoustic signal with a larger amplitude induced by the GR effect, as PA2 and PA4 in Figure 4 . The time interval between the two pulses is about 100 μs. The intensity modulation frequency of the CW laser (continuous wave laser) is 1 kHz, and the heating time is 30 μs. Since the thermal relaxation time of the spot is much smaller than the 1 ms period of the CW laser, the thermal energy generated by the CW laser (continuous wave laser) within each sequence can be dissipated, and the influence on the next sequence is negligible. Between each sequence, as shown in Figure 4 , the spatial light modulator SLM loads a series of ordered Zernike polynomials.

[0073] It should be noted that Figure 3In the diagram, HWP is a half-wave plate; BS is a beam splitter; PBS is a polarizing beam splitter; PD is a photodiode; L1, L2, and L3 are lenses; PH is a pinhole camera; SLM is a spatial light modulator; UT is an ultrasonic transducer; MRA is a right-angle reflecting prism; AMP is an amplifier; and DAQ is a data acquisition card. Figure 4 From top to bottom, the diagrams show the timing of the pulsed laser (the laser emitter in the initial photoacoustic microscopy assembly), the CW laser (continuous wave laser), and the photoacoustic signal. At time t1, the SLM loads a series of ordered Zernike polynomials to compensate for optical aberrations caused by the absorber, such that PA3 > PA1, PA4 > PA2, and (PA4-PA3) > (PA2–PA1).

[0074] The following is based on Figures 5-8 The specific device embodiments are used to illustrate the effects of the photoacoustic microscopy imaging device provided in this application.

[0075] This embodiment uses carbon fiber filament imaging to verify the effectiveness of AWA-GR-PAM. First, the order of the Zernike polynomial is set to 4 to 10, excluding piston, x-tilt, and y-tilt. The coefficient step size for traversing each order of Zernike polynomial is set to π rad, and the optimization range is -3π to 3π rads. Figure 5 and Figure 6 These are the maximum amplitude projection (MAP) images after AWA-GR correction and without AWA-GR correction, respectively. Comparing these two MAP images reveals that the normalized signal intensity after AWA-GR correction is generally greater than that without AWA-GR correction, and the MAP image after AWA-GR correction more clearly displays the characteristics of the carbon fiber filaments. Furthermore, Figure 7 It is along Figure 5 and Figure 6 The one-dimensional curve plotted by the white dashed line in the graph shows that AWA-GR correction can also enhance image contrast. Figure 8 Showing Figure 5 The phase map at the location indicated by the solid line box, used to compensate for sample-induced aberrations, shows an approximately 2.2-fold increase in normalized signal intensity at this location. These results highlight the advanced capabilities of AWA-GR-PAM in eliminating optical aberrations to provide sharp microstructure. Figure 7 The solid and dashed lines represent the normalized intensity distributions after AWA-GR correction and before AWA-GR correction, respectively.

[0076] In summary, this application modulates the first pulsed laser, the second pulsed laser, and the continuous wave laser using SLM, and develops AWA-GR-PAM to compensate for absorber-induced aberrations, with the intrinsic absorber acting as a guide star to provide acoustic feedback. According to the above embodiments, improvements in lateral resolution and signal intensity were observed when imaging carbon fiber filaments, demonstrating that PAM combined with AO can achieve high-quality beam focusing. This application can provide insights into the understanding of complex vascular networks.

[0077] This application also provides a computer device.

[0078] Please see Figure 9 , Figure 9 This is a schematic diagram of the structure of a computer device provided in an optional embodiment of this application, such as... Figure 9 As shown, the computer device includes one or more processors 10, memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processors can process instructions executed within the computer device, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple computer devices can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 8 Take a processor 10 as an example.

[0079] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GDA), or any combination thereof.

[0080] The memory 20 stores instructions executable by at least one processor 10 to cause at least one processor 10 to perform the method shown in the above embodiments.

[0081] The memory 20 can include a program storage area and a data storage area. The program storage area can store an operating system, application programs required for at least one function, and the like. The data storage area can store data created according to the use of the computer device, and the like. In addition, the memory 20 can include a high-speed random access memory, and can further include a non-transitory memory such as at least one of a magnetic disk storage device, a flash memory device, or other non-transitory solid state memory device. In some alternative embodiments, the memory 20 can optionally include a memory disposed remotely from the processor 10, which can be connected to the computer device through a network. Examples of the network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0082] The memory 20 can include a volatile memory such as a random access memory, and can further include a non-volatile memory such as a flash memory, a hard disk, or a solid state disk, and a combination thereof.

[0083] The computer device further includes a communication interface 30 for communication of the computer device with other devices or communication networks.

[0084] The embodiments of the present application further provide a computer readable storage medium. The method according to the embodiments of the present application can be implemented in hardware, firmware, or recorded in a storage medium, or implemented as computer code to be originally stored in a remote storage medium or a non-transitory machine readable storage medium and stored in a local storage medium through network downloading, so that the method described herein can be processed by such software on a storage medium using a general purpose computer, a special purpose processor, or programmable or special purpose hardware. The storage medium can be a magnetic disk, an optical disk, a read-only memory, a random access memory, a flash memory, a hard disk, or a solid state disk, and the like. Further, the storage medium can further include a combination of the above-mentioned kinds of memories. It can be understood that the computer, the processor, the microprocessor controller, or the programmable hardware includes a storage component that can store or receive software or computer code, when the software or computer code is accessed and executed by the computer, the processor, or the hardware, the method shown in the above embodiments is implemented.

[0085] Although the embodiments of the present application are described with reference to the drawings, various modifications and changes can be suggested by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes are intended to fall within the scope of the appended claims.

Claims

1. An adaptive photoacoustic microscopy imaging method, characterized in that, An adaptive photoacoustic microscopy imaging device is applied, the device comprising: an initial photoacoustic microscopy imaging component, a continuous-wave laser, and a spatial light modulator; the initial photoacoustic microscopy imaging component is used to acquire an image of the target to be imaged based on a first pulse laser and a second pulse laser; the continuous-wave laser is used to emit a continuous-wave laser toward the target to be imaged during the imaging process of the initial photoacoustic microscopy imaging component; the method comprises: The initial photoacoustic microscopy imaging component is controlled to emit a first pulse laser and a second pulse laser, and the continuous wave laser is controlled to emit a continuous wave laser. The spatial light modulator is controlled to perform wavefront modulation on the first pulsed laser, the second pulsed laser, and the continuous wave laser; wherein, during wavefront modulation, the spatial light modulator uses a differential photoacoustic signal as feedback. The first and second laser pulses excite the absorber (i.e., the target to be imaged) sequentially with a sub-microsecond delay. The initial voltage boost generated by the first laser pulse is as follows: p1=Γ0η th m a F (1) Where Γ0 is the Grunersen parameter at the initial temperature, η th It is the heat conversion efficiency, μ a Where F is the light absorption coefficient and F is the light flux, during the thermal relaxation time of the first laser pulse, the second laser pulse excites the same absorber, resulting in another initial voltage boost: p2=(Γ0+Gη th m a F)h th m a F (2) Where G is a coefficient relating the change in the Glunesian parameter to the energy absorbed by the first laser pulse. Assuming the luminous flux follows a two-dimensional Gaussian distribution in the transverse direction, the photoacoustic amplitude generated by the first laser pulse is: (3) Where k is a constant related to the photoacoustic signal detection sensitivity, E is the pulse energy, w is the beam waist of the Gaussian beam; x, y are the transverse coordinates; the photoacoustic amplitude generated by the second laser pulse is: (4) Performing differential operations on equations (3) and (4) yields the differential photoacoustic signal: (5) The spatial light modulator is used to perform the following steps to perform wavefront modulation on the first pulsed laser, the second pulsed laser, and the continuous wave laser: Obtain several ordered Zernike polynomials; wherein the Zernike polynomials are used to describe the optical aberrations generated by the initial photoacoustic microscopy imaging component; Several ordered Zernike polynomials are sequentially loaded into a spatial light modulator to determine the coefficients corresponding to the ordered Zernike polynomials; during the process of determining the coefficients corresponding to the ordered Zernike polynomials, the differential photoacoustic signal increases. Based on the coefficients corresponding to several ordered Zernike polynomials, wavefront modulation is performed on the first pulsed laser, the second pulsed laser, and the continuous wave laser.

2. An adaptive photoacoustic microscopy imaging device, characterized in that, The apparatus for performing the method of claim 1, comprising: an initial photoacoustic microscopy imaging component, a continuous-wave laser, and a spatial light modulator; wherein... The initial photoacoustic microscopy imaging component is used to acquire an image of the target to be imaged based on a first pulse laser and a second pulse laser. The continuous wave laser is used to emit continuous wave laser light toward the target to be imaged during the imaging process of the initial photoacoustic microscopy imaging assembly. The spatial light modulator is used to perform wavefront modulation on the first pulsed laser, the second pulsed laser, and the continuous wave laser; wherein, during wavefront modulation, the spatial light modulator uses a differential photoacoustic signal as feedback. The first and second laser pulses excite the absorber (i.e., the target to be imaged) sequentially with a sub-microsecond delay. The initial voltage boost generated by the first laser pulse is as follows: p1=Γ0η th m a F (1) Where Γ0 is the Grunersen parameter at the initial temperature, η th It is the heat conversion efficiency, μ a Where F is the light absorption coefficient and F is the light flux, during the thermal relaxation time of the first laser pulse, the second laser pulse excites the same absorber, resulting in another initial voltage boost: p2=(Γ0+Gη th m a F)h th m a F (2) Where G is a coefficient relating the change in the Glunesian parameter to the energy absorbed by the first laser pulse. Assuming the luminous flux follows a two-dimensional Gaussian distribution in the transverse direction, the photoacoustic amplitude generated by the first laser pulse is: （3） Where k is a constant related to the photoacoustic signal detection sensitivity, E is the pulse energy, w is the beam waist of the Gaussian beam; x, y are the transverse coordinates; the photoacoustic amplitude generated by the second laser pulse is: （4） Performing differential operations on equations (3) and (4) yields the differential photoacoustic signal: （5） The spatial light modulator is used to perform the following steps to perform wavefront modulation on the first pulsed laser, the second pulsed laser, and the continuous wave laser: Obtain several ordered Zernike polynomials; wherein the Zernike polynomials are used to describe the optical aberrations generated by the initial photoacoustic microscopy imaging component; Several ordered Zernike polynomials are sequentially loaded into a spatial light modulator to determine the coefficients corresponding to the ordered Zernike polynomials; during the process of determining the coefficients corresponding to the ordered Zernike polynomials, the differential photoacoustic signal increases. Based on the coefficients corresponding to several ordered Zernike polynomials, wavefront modulation is performed on the first pulsed laser, the second pulsed laser, and the continuous wave laser.

3. The apparatus according to claim 2, characterized in that, The initial photoacoustic microscopy assembly includes: a laser emitter, a laser focusing tool, an ultrasonic transducer, and a data processing device.

4. The apparatus according to claim 3, characterized in that, Several ordered Zernike polynomials are sequentially loaded into a spatial light modulator, and the coefficients corresponding to these ordered Zernike polynomials are determined, including: A feedback loop is constructed between the ultrasonic transducer and the data processing device in the spatial light modulator and the initial photoacoustic microscopy assembly. Based on the feedback loop, several ordered Zernike polynomials are traversed to determine the coefficients corresponding to the ordered Zernike polynomials.

5. The apparatus according to claim 2, characterized in that, The spatial light modulator is a reflective liquid crystal spatial light modulator.

6. The apparatus according to claim 3, characterized in that, The ultrasonic transducer has a center frequency of 50MHz and a bandwidth of 31.40-73.25MHz.

7. The apparatus according to claim 4, characterized in that, The Zernike polynomials have an order of 4-10.

8. A computer device, characterized in that, include: The system includes a memory and a processor, which are interconnected. The memory stores computer instructions, and the processor executes the computer instructions to perform the adaptive photoacoustic microscopy imaging method of claim 1.

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