CN114727760A - Photoacoustic imaging method and photoacoustic imaging system - Google Patents

Abstract

A photoacoustic imaging method and a system thereof are provided, the photoacoustic imaging method comprises the steps of controlling a photoacoustic composite probe to emit laser once to a tissue to be detected in a first photoacoustic imaging mode to obtain a frame of photoacoustic image; in a second photoacoustic imaging mode, controlling a photoacoustic composite probe to emit laser to the tissue to be detected at least twice to obtain a frame of photoacoustic image; and when the moving speed of the photoacoustic composite probe is detected to be smaller than a first preset threshold value, switching from the first photoacoustic imaging mode to the second photoacoustic imaging mode. The switching between the first photoacoustic imaging mode and the second photoacoustic imaging mode is determined by detecting the moving speed of the photoacoustic composite probe, so that different requirements of a user on photoacoustic images when the photoacoustic composite probe is moved at different speeds are met.

Description

Photoacoustic imaging method and photoacoustic imaging system

technical field

The invention relates to the field of medical instruments, in particular to a photoacoustic imaging method and a photoacoustic imaging system.

Background technique

In the application of biophotoacoustic imaging, in order to ensure sufficient penetration depth (greater than 3 cm), high-energy (tens of mJ level) nanosecond solid-state lasers are usually used. The emission pulse repetition frequency (PRF) of this kind of laser is relatively low, generally tens of Hz. The cost of increasing the PRF is very high, and the power consumption, volume and noise of the system will increase exponentially. Limited by the PRF of the laser, the frame rate of photoacoustic imaging will also be relatively low.

In order to ensure the imaging frame rate, the emission strategy usually adopts one frame of laser emission to obtain one frame of image, but it will lead to the problem of low signal-to-noise ratio (SNR) and penetrating power of the image. Imaging frame rate will be lost. Based on the above problems, the user experience is poor.

SUMMARY OF THE INVENTION

A first aspect of the present application provides a photoacoustic imaging method, comprising:

In the first photoacoustic imaging mode, control the photoacoustic composite probe to emit a laser to the tissue to be tested;

Controlling the photoacoustic composite probe to receive a primary ultrasonic wave generated by the tissue to be tested under the action of the primary laser to obtain a photoacoustic electrical signal;

processing the one photoacoustic electrical signal to obtain a frame of photoacoustic image;

Detect the moving speed of the photoacoustic composite probe;

When the detected moving speed of the photoacoustic composite probe is less than a first preset threshold, switching from the first photoacoustic imaging mode to the second photoacoustic imaging mode;

In the second photoacoustic imaging mode, controlling the photoacoustic composite probe to emit laser light to the tissue to be measured at least twice;

The photoacoustic composite probe is controlled to respectively receive at least two ultrasonic waves generated by the tissue to be tested under the action of the at least two lasers, so as to obtain at least two photoacoustic electrical signals, wherein the tissue to be tested is emitted in one emission. The ultrasonic wave generated under the action of the laser is an ultrasonic wave, and the photoacoustic electrical signal obtained by receiving an ultrasonic wave is a photoacoustic electrical signal;

One frame of photoacoustic image is obtained by processing the at least two photoacoustic electrical signals.

A second aspect of the present application provides a photoacoustic imaging method, comprising:

Detect the moving speed of the photoacoustic composite probe;

determining the number N of laser firings based on the moving speed;

Controlling the photoacoustic composite probe to emit N times of laser light to the tissue to be tested;

The photoacoustic composite probe is controlled to receive N times of ultrasonic waves generated by the tissue to be tested under the action of the N times of laser light to obtain N photoacoustic electrical signals, wherein the tissue to be tested is under the action of a laser emitted once The generated ultrasonic wave is an ultrasonic wave, and the photoacoustic electric signal obtained by receiving an ultrasonic wave is a photoacoustic electric signal;

One frame of photoacoustic image is obtained by processing the N photoacoustic electrical signals.

A third aspect of the present application provides a photoacoustic imaging method, comprising:

Detect the moving speed of the photoacoustic composite probe;

When the moving speed satisfies the first preset condition, controlling the photoacoustic composite probe not to emit laser light to the tissue to be measured;

When the moving speed satisfies the second preset condition, the photoacoustic composite probe is controlled to emit laser light to the tissue to be tested, and the photoacoustic composite probe is controlled to receive ultrasonic waves generated by the tissue to be tested under the action of the laser , to obtain a photoacoustic electrical signal, and process the photoacoustic electrical signal to obtain a photoacoustic image.

A fourth aspect of the present application provides a photoacoustic imaging system, including: a laser, a photoacoustic composite probe, and a processor;

The laser is used to generate laser light and emit the laser light to the target tissue through the optical transmission device;

The photoacoustic composite probe is used for receiving the photoacoustic signal returned from the target tissue;

The processor is configured to process the photoacoustic signal to obtain a photoacoustic image;

The processor is further configured to execute the method described in any one of the first aspect to the third aspect.

A fifth aspect of the present application provides a computer-readable storage medium, where computer-executable instructions are stored in the computer-readable storage medium, and when the computer-executable instructions are executed by a processor, are used to implement the first to third aspects The method of any one of the aspects.

The embodiment of the present application determines the switching between the first photoacoustic imaging mode and the second photoacoustic imaging mode by detecting the moving speed of the photoacoustic composite probe, which meets the different needs of the user when moving the photoacoustic composite probe at different speeds.

Description of drawings

1 is a schematic diagram of a photoacoustic imaging system according to an embodiment of the application;

2 is a flowchart of a photoacoustic imaging method according to an embodiment of the present application;

3 is a flowchart of a photoacoustic imaging method according to another embodiment of the present application;

FIG. 4 is a flowchart of a photoacoustic imaging method according to still another embodiment of the present application.

Detailed ways

The present invention will be further described in detail below through specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments have used associated similar element numbers. In the following embodiments, many details are described so that the present application can be better understood. However, those skilled in the art will readily recognize that some of the features may be omitted under different circumstances, or may be replaced by other elements, materials, and methods. In some cases, some operations related to the present application are not shown or described in the specification, in order to avoid the core part of the present application from being overwhelmed by excessive description, and for those skilled in the art, these are described in detail. The relevant operations are not necessary, and they can fully understand the relevant operations according to the descriptions in the specification and general technical knowledge in the field.

Additionally, the features, acts, or characteristics described in the specification may be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can also be exchanged or adjusted in order in a manner obvious to those skilled in the art. Therefore, the various sequences in the specification and drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a necessary order unless otherwise stated, a certain order must be followed.

The serial numbers themselves, such as "first", "second", etc., for the components herein are only used to distinguish the described objects, and do not have any order or technical meaning. The "connection" and "connection" mentioned in this application, unless otherwise specified, include both direct and indirect connections (connections).

As shown in FIG. 1 , it is a schematic structural block diagram of a photoacoustic imaging system in an embodiment of the present application. The imaging system may include a photoacoustic composite probe 20 , a laser 90 , a transmitting circuit 310 , a receiving circuit 320 , a processor 70 , a beam forming module 40 , a display 80 and a memory 60 . Of course, the imaging system 10 may also include other devices or devices not shown in the figures.

Optionally, the photoacoustic imaging system can also perform ultrasonic imaging. When performing ultrasonic imaging, the transmitting circuit 310 can excite the photoacoustic composite probe 20 to transmit ultrasonic waves to the tissue to be measured. After the photoacoustic composite probe 20 transmits ultrasonic waves, the receiving circuit 320 may receive the ultrasonic echoes returned from the tissue to be measured through the photoacoustic composite probe 20 to obtain ultrasonic echo signals. The ultrasonic echo signal is directly or indirectly subjected to beam forming processing by the beam forming module to obtain an ultrasonic image signal, which is sent to the processor 70 . The processor 70 processes the ultrasound image signal to obtain an ultrasound image of the tissue to be measured.

The photoacoustic imaging system can perform photoacoustic imaging. When performing photoacoustic imaging, the laser 90 can generate laser light. The laser 90 is connected with an optical transmission device. The optical transmission device includes optical fibers (fiber bundles), light guide arms, etc. The optical transmission device is coupled to the photoacoustic composite probe 20. The laser light generated by the laser 90 emits laser light to the tissue to be tested through the optical transmission device coupled to the photoacoustic composite probe 20, and the tissue to be tested absorbs the ultrasonic waves generated by the laser energy. After the laser is emitted to the tissue to be measured, the receiving circuit 320 may also receive the ultrasonic wave returned by the tissue to be measured through the photoacoustic composite probe 20 to obtain a photoacoustic electrical signal. The photoacoustic electrical signal is directly or processed and sent to the processor 70 to obtain a photoacoustic image of the tissue to be tested. The aforementioned ultrasound images and photoacoustic images can be stored in the memory 60 or displayed on the display 80 .

In one embodiment of the present application, the photoacoustic imaging system may only have a photoacoustic imaging function to form a photoacoustic image; it may also have both a photoacoustic imaging function and an ultrasonic imaging function to form an ultrasonic image and a photoacoustic image, and further can also form a photoacoustic imaging function. The fusion image of the ultrasonic image and the photoacoustic image, wherein the imaging mode of the ultrasonic imaging is not limited, and can be a gray-scale imaging mode, a color imaging mode, a Doppler imaging mode, an elastography mode, and the like.

In an embodiment of the present application, the processor 70 further includes a timing controller, and the timing controller can generate a series of timing control signals according to a certain logic. The reception of the wave signal, on the other hand, can be used to control the laser turn-on of the laser and the reception of the photoacoustic signal, so as to avoid signal aliasing and interference through timing control.

It should be noted that, in this embodiment, the optical transmission device coupled on the photoacoustic composite probe 20 emits laser light to the tissue to be tested, and the optical transmission device can be arranged outside the ultrasonic probe shell to form the photoacoustic composite probe 20, for example , couple the optical transmission device outside the ultrasonic probe shell, use the optical transmission device to conduct the laser light to both sides of the ultrasonic probe, and irradiate the tissue to be tested by means of back-lighting; the optical transmission device can also be set in the ultrasonic probe shell. Inside, the photoacoustic composite probe 20 is formed. For example, the optical transmission device can be directly coupled with the ultrasonic transducer, and is completely or partially surrounded by the shell to form a probe integrating laser emission and ultrasonic emission and reception. In some implementations, the laser 90 can also directly irradiate the tissue to be measured through an optical transmission device, and the optical transmission device is not coupled with the probe, that is, the optical transmission device and the ultrasonic probe are two independent parts, and the two integrally formed Photoacoustic composite probe 20 .

In an embodiment of the present application, the photoacoustic composite probe 20 may further include a machine scanner, through which the photoacoustic composite probe 20 can receive ultrasonic waves from different directions, and the received ultrasonic waves can be processed to obtain ultrasonic images. or photoacoustic images. In some implementations, the mechanical scanner can be coupled to the photoacoustic composite probe 20, that is, the photoacoustic composite probe 20 integrates the function of mechanical scanning; The mechanical scanner drives the probe movement.

In one embodiment of the present application, the aforementioned display 80 may be a built-in touch display screen, a liquid crystal display screen, etc. Displays on electronic devices such as mobile phones, tablets, etc.

In an embodiment of the present application, the aforementioned memory 60 may be a flash memory card, a solid-state memory, a hard disk, or the like.

In one embodiment of the present application, the aforementioned processor 70 may be implemented by software, hardware, firmware, or a combination thereof, and may use circuits, single or multiple application specific integrated circuits (ASIC), single or multiple general-purpose integrated circuits circuit, single or multiple microprocessors, single or multiple programmable logic devices, or a combination of the foregoing circuits or devices, or other suitable circuits or devices, so that the processor 70 can perform the various embodiments of the present application. corresponding steps of the imaging method.

The signal processing process of photoacoustic imaging is exemplarily described below with reference to the accompanying drawings.

The photoacoustic composite probe 20 may include an ultrasonic transducer and an optical transmission device, wherein the ultrasonic transducer includes a transducer (not shown in the figure) composed of a plurality of array elements arranged in an array, and the plurality of array elements are arranged in a Arrays form a linear array, or are arranged in a two-dimensional matrix to form an area array, and multiple array elements can also form a convex array. The array element is used to transmit the ultrasonic beam according to the excitation electrical signal, or convert the received ultrasonic beam into an electrical signal. Therefore, each array element can be used to realize mutual conversion between electrical pulse signals and ultrasonic beams, so as to transmit ultrasonic waves to the target area of human tissue (for example, the fetus in this embodiment), and can also be used to receive ultrasonic waves reflected by the tissue. waves, and receive ultrasound waves produced by tissue under the action of the laser. The photoacoustic composite probe 20 in this embodiment can be a linear array probe for acquiring a two-dimensional ultrasound image and a two-dimensional photoacoustic image of a fetus, or a volume probe for acquiring three-dimensional ultrasound volume data and a three-dimensional optical image of the fetus. volume data.

In this embodiment, the user selects an appropriate position and angle to emit laser light to the tissue 10 to be tested by moving the photoacoustic composite probe 20, and receives the ultrasonic waves generated by the tissue 10 to be tested under the action of the laser, and obtains and outputs the photoacoustic converted from the ultrasonic waves. The electrical signal, the photoacoustic electrical signal can be a channel analog electrical signal formed by the receiving array element as a channel, which carries amplitude information, frequency information and time information.

The receiving circuit 320 is used for receiving the photoacoustic electrical signal from the photoacoustic composite probe 20 and processing the electrical signal of the ultrasonic echo. Receive circuit 320 may include one or more amplifiers, analog-to-digital converters (ADCs), and the like. The amplifier is used to amplify the received photoacoustic electrical signal after proper gain compensation, and the analog-to-digital converter is used to sample the analog echo signal at a predetermined time interval, thereby converting it into a photoacoustic digitized signal, and the photoacoustic digitized signal is still retained. There is amplitude information, frequency information and phase information. The photoacoustic digitized signal output by the analog-to-digital conversion module can be output to the beam forming module 40 for processing, or output to the memory 60 for storage.

The beam forming module 40 is connected to the signal of the receiving circuit 320, and is used to perform beam forming processing such as corresponding delay and weighted summation on the signal output by the receiving circuit 320. Because the distance from the ultrasonic receiving point in the tested tissue to the receiving array element is different , therefore, the channel data of the same receiving point output by different receiving array elements have delay differences, and it is necessary to perform delay processing, align the phases, and perform weighted summation of different channel data of the same receiving point to obtain the beam-synthesized beam. sound image signal. In some embodiments, the beam forming module 40 may output the photoacoustic image signal to the memory 60 for buffering or storage, or directly output the photoacoustic image signal to the image processing module 720 of the processor 70 for image processing.

The beamforming module 40 may use hardware, firmware or software to perform the above functions. For example, the beamforming module 40 may include a central controller circuit (CPU) capable of processing input data according to specific logic instructions, one or more microprocessor chips or any other electronic components, when beamforming module 40 is implemented in software, that can execute instructions stored on a tangible and non-transitory computer readable medium (eg, memory 60 ) to perform beamforming using any suitable beamforming method calculate.

The processor 70 is for a central controller circuit (CPU), one or more microprocessors, a graphics controller circuit (GPU), or any other electronic component configured to be able to process input data according to specific logic instructions, which may Instructions or predetermined instructions perform control on peripheral electronic components, or perform data reading and/or saving on the memory 60, and input data can also be processed by executing programs in the memory 60, such as collecting data according to one or more operating modes. The photoacoustic signal performs one or more processing operations including, but not limited to, adjusting or limiting the laser emission or stopping of the laser 90, generating an ultrasound image or a photoacoustic image for subsequent display on the display 80 of the human-computer interaction device, or Adjust or define the content and form displayed on the display 80, or adjust one or more image display settings displayed on the display 80 (eg, ultrasound images, interface components, locate a region of interest). The processor 70 in this embodiment may cooperate with other components to execute the photoacoustic imaging method provided by any method embodiment in this application.

The image processing module 720 is used for processing the photoacoustic image signal output by the beam forming module 40 to generate a photoacoustic image with varying signal intensity within the scanning range, and the photoacoustic image reflects the distribution of light absorbing substances in human tissue. The image processing module 720 can output the photoacoustic image to the display 80 of the human-computer interaction device for display.

The human-computer interaction device is used for human-computer interaction, that is, receiving the user's input and outputting visual information; it can receive the user's input by using a keyboard, operation buttons, mouse, trackball, etc., or a touch control integrated with the display. The display screen 80 is used for its output visual information.

The memory 60 may be a tangible and non-transitory computer-readable medium, such as a flash memory card, solid state memory, hard disk, etc., for storing data or programs, for example, the memory 60 may be used for storing acquired ultrasound data or a processor 70 generated image frames that are not immediately displayed, or memory 60 may store a graphical user interface, one or more default image display settings, programming instructions for the processor, beamforming module, or IQ decoding module.

Embodiments of the photoacoustic imaging method and the photoacoustic imaging system provided by the present application will be introduced below in conjunction with the composition of the photoacoustic imaging system.

As shown in FIG. 2 , the present application provides a photoacoustic imaging method, which can switch between two photoacoustic imaging modes based on the speed of the photoacoustic composite probe. The method may include the following steps:

Step 201, in the first photoacoustic imaging mode, control the photoacoustic composite probe to emit a laser to the tissue to be measured once;

In the first photoacoustic imaging mode, the processor 70 controls the photoacoustic composite probe 20 to emit a laser to the tissue to be tested, where the first laser is the laser 90, which is the process from the next emission to the stop of emission under the control of the timing controller. After emitting the laser once, the acoustic composite probe 20 enters the stage of receiving the ultrasonic waves generated by the tissue to be tested under the action of the laser.

Step 202, controlling the photoacoustic composite probe to receive a primary ultrasonic wave generated by the tissue to be tested under the action of the primary laser to obtain a photoacoustic electrical signal;

The processor 70 controls the photoacoustic composite probe 20 to receive an ultrasonic wave generated by the tissue to be tested under the action of a laser, so as to obtain a photoacoustic electrical signal. After the photoacoustic composite probe 20 emits a laser to the tissue to be tested, the tissue to be tested generates ultrasonic waves under the action of the laser, and the photoacoustic composite probe 20 receives the ultrasonic waves propagated from the tissue to be tested, and converts the received ultrasonic waves into ultrasonic waves. Photoacoustic and electrical signals for subsequent processing. The first ultrasonic wave here is the ultrasonic wave generated by the tissue to be tested under the action of a laser. The part of the ultrasonic wave generated under the action of the first laser is received by the photoacoustic composite probe 20, and the photoacoustic electric signal obtained by the photoacoustic composite probe 20 is processed. For a photoacoustic electrical signal.

Step 203, processing the one photoacoustic electrical signal to obtain a frame of photoacoustic image;

Processing a photoacoustic electrical signal to obtain a frame of photoacoustic image, the photoacoustic electrical signal can be converted into an ultrasonic digital signal through the analog-to-digital conversion module, and the ultrasonic digital signal is processed by the beam synthesis module to obtain a photoacoustic image signal. The image signal is further processed to obtain a frame of photoacoustic image, and the photoacoustic image can be presented to the user through the display 80 . It should be emphasized that processing a photoacoustic electrical signal to obtain a frame of photoacoustic image may not be limited to the above steps, and may also include time gain compensation, IQ demodulation, and logarithmic compression. In this application, the photoacoustic and electrical signals obtained by the photoacoustic composite probe 20 after analog-to-digital conversion and before entering the beam synthesis are called ultrasonic digital signals. There may still be many signal processing links after digital conversion and before beamforming. The ultrasonic digital signals referred to in this application may include signals at various stages after analog-to-digital conversion and before beamforming, and signals at various stages after analog-to-digital conversion and before beamforming. The signals of the stages are all applicable to the technical solutions related to the ultrasonic digital signal in the various embodiments of the present application. Similarly, in this application, the signal between the ultrasonic digital signal after beam synthesis and the output as a photoacoustic image is called a photoacoustic image signal, and the photoacoustic image signal can be directly output as a photoacoustic image for display. It can also be a signal that needs to be processed by one or more steps before it can be output as a photoacoustic image. The signal between the beam synthesis and the output as a photoacoustic image can be applied to the various embodiments of the present application. Technical solutions related to acoustic image signals.

Step 204, detecting the moving speed of the photoacoustic composite probe;

The processor 70 can detect the moving speed of the photoacoustic composite probe 20, where the moving speed of the photoacoustic composite probe 20 can be the moving speed of the photoacoustic composite probe on the tissue to be measured, or it can be the speed of the photoacoustic composite probe 20 in space. movement speed.

It should be emphasized that the execution order of the steps in the various embodiments of the present application is not limited. Unless otherwise specified, the steps may be executed in the order shown in the figures, or may be executed in any other feasible order. In this embodiment, the detection of the moving speed of the photoacoustic composite probe 20 is performed before step 201 , it may be performed after step 201 and before step 202 , or it may be performed after step 202 and before step 203 , etc. execution order.

Step 205, when the detected moving speed of the photoacoustic composite probe is less than a first preset threshold, switch from the first photoacoustic imaging mode to the second photoacoustic imaging mode;

The processor 70 controls to switch from the first photoacoustic imaging mode to the second photoacoustic imaging mode when detecting that the moving speed of the photoacoustic composite probe 20 is less than the first threshold. The moving speed of the photoacoustic composite probe 20 is used as the switching condition between the two photoacoustic imaging modes, and the optimal photoacoustic imaging mode under different probe moving speeds can be matched according to the different moving speeds of the probes, so as to satisfy users who move at different speeds. The photoacoustic composite probe 20 has different photoacoustic image requirements. The first preset threshold here may be factory preset, or may be set by the user.

Step 206, in the second photoacoustic imaging mode, controlling the photoacoustic composite probe to emit laser light to the tissue to be measured at least twice;

In the second photoacoustic imaging mode, the processor 70 controls the photoacoustic composite probe 20 to emit laser light to the tissue to be measured at least twice, where the laser 90 repeatedly emits laser light at least twice under the control of the timing controller. and stop the process of emitting the laser.

Step 207: Control the photoacoustic composite probe to receive at least two ultrasonic waves generated by the tissue to be tested under the action of the at least two lasers to obtain at least two photoacoustic electrical signals, wherein the tissue to be tested is The ultrasonic wave generated under the action of the laser emitted once is an ultrasonic wave, and the photoacoustic electrical signal obtained by receiving an ultrasonic wave is a photoacoustic electrical signal;

The processor 70 controls the photoacoustic composite probe 20 to respectively receive at least two ultrasonic waves generated by the tissue to be tested under the action of the at least two lasers, so as to obtain at least two photoacoustic electrical signals. The photoacoustic composite probe 20 emits a laser to the tissue to be tested, which will generate an ultrasonic wave in the tissue to be tested. The photoacoustic composite probe 20 receives an ultrasonic wave generated in the tissue to be tested and processes it to obtain a photoacoustic electrical signal. Repeat this process for at least one time. twice, the photoacoustic composite probe 20 can obtain at least two photoacoustic electrical signals.

Step 208, processing the at least two photoacoustic electrical signals to obtain a frame of photoacoustic image.

Processing the at least two photoacoustic electrical signals to obtain a frame of photoacoustic image, which can be obtained by processing at least two photoacoustic electrical signals through an analog-to-digital conversion module, a beam synthesis module and a processor to obtain a frame of photoacoustic image, not limited to analog-digital The conversion module, the beam synthesis module and the processor may also include other processing modules in the process of processing the photoacoustic electrical signal to obtain a frame of photoacoustic image, which is not limited in this embodiment.

In the first photoacoustic imaging mode, the photoacoustic composite probe 20 emits a laser to the tissue to be tested to form a frame of photoacoustic image, and the imaging frame rate is relatively fast, but the image quality is not high; in the second photoacoustic imaging mode, the laser is emitted at least twice. , into a photoacoustic image, due to the large number of transmissions and the recovered photoacoustic electrical signals, a higher quality photoacoustic image can be obtained, but at the same time, the imaging frame rate will decrease accordingly, and the update of the photoacoustic image will be slow. In general, when the first photoacoustic imaging mode is used for photoacoustic imaging, the frame rate and image quality can meet the requirements of general photoacoustic imaging, but when the user moves the photoacoustic composite probe 20 slowly or keeps the photoacoustic composite probe 20 in standby When the tissue under test is not moving, the user often needs to carefully observe the photoacoustic image of the area of the tissue to be tested. At this time, the quality of the photoacoustic image in the first mode will not meet the needs of the user. In this embodiment, the moving speed of the photoacoustic composite probe 20 is detected. When the moving speed of the photoacoustic composite probe 20 is less than the first preset threshold, the first imaging mode is switched to the second imaging mode. At this time, the user moves slowly or Keeping the photoacoustic composite probe 20 still, it is often necessary to carefully observe the photoacoustic image in this area, which requires high image quality of the photoacoustic image, and because the photoacoustic composite probe 20 moves slowly or does not move, the photoacoustic image does not change much. , the user does not have high requirements for the frame rate of photoacoustic imaging, so in the second imaging mode, a photoacoustic image is generated by emitting the laser to the tissue to be tested at least twice, giving up the high imaging frame rate, but ensuring the light The quality of the acoustic image meets the needs of the user when moving the photoacoustic composite probe 20 slowly or keeping the photoacoustic composite probe 20 still. In this embodiment, the switching of the first photoacoustic imaging mode and the second photoacoustic imaging mode is controlled by detecting the moving speed of the photoacoustic composite probe 20, so as to meet the different needs of the user for moving the photoacoustic composite probe 20 in different scenarios.

In an embodiment, in the second photoacoustic imaging mode, processing at least two photoacoustic signals to obtain one frame of photoacoustic image may be performed by averaging the photoacoustic digitized signals, which may specifically include: averaging the at least two photoacoustic signals. performing analog-to-digital conversion on the photoacoustic electrical signal to obtain at least two photoacoustic digitized signals; averaging the at least two photoacoustic digitized signals to obtain an averaged photoacoustic digitized signal; performing beam synthesis on the averaged photoacoustic digitized signal, to obtain a target photoacoustic image signal; process the target photoacoustic image signal to obtain a frame of photoacoustic image.

The photoacoustic composite probe 20 emits laser light at least twice to the tissue to be tested, and the tissue to be tested generates at least two ultrasonic waves under the action of the laser light. electric signal. Further, by converting the at least two photoacoustic electrical signals into at least two ultrasonic digital signals through the analog-to-digital conversion module, a photoacoustic electrical signal can be obtained for one laser emission, and the one photoacoustic electrical signal is converted into an ultrasonic digital signal. , the at least two photoacoustic electrical signals are respectively converted into at least two ultrasonic digital signals; it is also possible to obtain one photoacoustic electrical signal for one laser emission, after obtaining at least two photoacoustic electrical signals, the at least two The photoacoustic electrical signal is converted into at least two ultrasonic digital signals. The at least two photoacoustic digitized signals are averaged to obtain an average photoacoustic digitized signal. After averaging at least two photoacoustic digitized signals, random noise in a single photoacoustic digitized signal can be overcome. The quality of the average photoacoustic digitized signal must be Higher quality than a single photoacoustic digitized signal. Further, beam synthesis is performed on the average photoacoustic digitized signal to obtain the target photoacoustic image signal, and the target photoacoustic image signal is processed to obtain a frame of photoacoustic image. The signal-to-noise ratio of the photoacoustic image is higher than the signal-to-noise ratio of the photoacoustic image formed by a single photoacoustic digitized signal, which can satisfy the user's concern for the quality of the photoacoustic image when moving the photoacoustic composite probe 20 slowly or keeping the photoacoustic composite probe 20 stationary. requirements.

It should be noted that the averaging of at least two photoacoustic digitized signals can be the averaging of the signals in any processing stage after analog-to-digital conversion to before beam synthesis, and then the obtained averaged photoacoustic digitized signals can be directly beam synthesized. , the obtained average photoacoustic digitized signal can also be subjected to other processing steps before beamforming. At least two photoacoustic digitized signals are averaged to obtain an average photoacoustic digitized signal, at least two signals are converted into one signal, and a frame of photoacoustic image is obtained subsequently, although the imaging frame rate at this time is compared with a photoacoustic digitized signal. Obtaining a frame of photoacoustic image has decreased, but the quality of the photoacoustic image has been improved. In the scenario where the user moves the photoacoustic composite probe 20 slowly or not, it is in line with the user's need to observe the photoacoustic image carefully and the frame rate of the photoacoustic imaging. Less demanding needs.

In an embodiment, in the second photoacoustic imaging mode, processing two photoacoustic signals to obtain one frame of photoacoustic image may be performed by averaging the photoacoustic image signals, which may specifically include: averaging the at least two photoacoustic signals. performing analog-to-digital conversion on the acoustic and electrical signals to obtain at least two photoacoustic digitized signals; performing beam synthesis on the at least two photoacoustic digitized signals to obtain at least two photoacoustic image signals; averaging to obtain an average photoacoustic image signal; processing the average photoacoustic image signal to obtain a frame of photoacoustic image.

The photoacoustic composite probe 20 emits laser light at least twice to the tissue to be tested, and the tissue to be tested generates at least two ultrasonic waves under the action of the laser light. electric signal. Perform analog-to-digital conversion on the at least two photoacoustic electrical signals to obtain at least two photoacoustic digitized signals, and perform beam synthesis on the at least two photoacoustic digitized signals to obtain at least two photoacoustic image signals, similar to the above embodiment , the beam synthesis process here may be that each time a photoacoustic digitized signal is generated, a photoacoustic image signal is obtained by performing a beam synthesis, and the at least two photoacoustic digitized signals are respectively beam synthesized to obtain at least two photoacoustic image signals; It is also possible to convert the at least two photoacoustic digitized signals into at least two photoacoustic image signals together after generating the at least two photoacoustic digitized signals. The at least two photoacoustic image signals are averaged to obtain an average photoacoustic image signal. After averaging at least two photoacoustic image signals, random noise in a single photoacoustic image signal can be overcome. Higher quality than a single photoacoustic image signal. Further, the average photoacoustic image signal is processed to obtain a frame of photoacoustic image. Since the quality of the average photoacoustic image signal is high at this time, the signal-to-noise ratio of the obtained photoacoustic image is relative to that of a single photoacoustic image signal. The signal-to-noise ratio of the photoacoustic image is high, which can meet the user's requirements for the quality of the photoacoustic image when the photoacoustic composite probe 20 is slowly moved or the photoacoustic composite probe 20 is kept stationary.

It should be noted that the averaging of the at least two photoacoustic image signals may be the averaging of the signals in any processing stage after beamforming to the output of the photoacoustic image, and the obtained averaged photoacoustic image signals may be directly processed subsequently to obtain the average value. To obtain a photoacoustic image, it is also possible to perform other processing on the obtained average photoacoustic image signal and then process to obtain a frame of photoacoustic image. At least two photoacoustic image signals are averaged to obtain an average photoacoustic image signal, at least two signals are converted into one signal, and a frame of photoacoustic image is obtained subsequently, although the imaging frame rate at this time is compared with that of one photoacoustic image signal. One frame of photoacoustic image has decreased, but the quality of the photoacoustic image has been improved. In the scene where the user moves the photoacoustic composite probe 20 slowly or not, it meets the user's need to observe the photoacoustic image carefully and the frame rate requirements of the photoacoustic imaging. low demand.

In the second photoacoustic imaging mode, at least two photoacoustic electrical signals are processed to obtain a frame of photoacoustic image, and at least two photoacoustic digital signals are averaged, or at least two photoacoustic image signals are averaged. The laser can be emitted multiple times to generate a frame of photoacoustic image to improve the quality of the photoacoustic image. Among them, at least two photoacoustic digitized signals are averaged, and then the average photoacoustic digitized signal is beamformed, and the target photoacoustic image signal can be obtained by only one beam synthesis, thereby obtaining a frame of photoacoustic image; At least two photoacoustic image signals are averaged, and at least two photoacoustic digitized signals need to be beamformed at least twice to obtain at least two photoacoustic image signals, and then at least two photoacoustic image signals are averaged to obtain a frame photoacoustic image; in comparison, the number of beamforming operations required to average the photoacoustic digitized signal is less than that of the photoacoustic image signal, the total calculation amount is small, and the processing time is faster, which can guarantee While improving the quality of photoacoustic images, the speed of photoacoustic imaging is improved.

For step 204, the moving speed of the photoacoustic composite probe is detected, specifically, a sensor or ultrasonic image detection method can be used.

In one embodiment, the moving speed of the photoacoustic composite probe can be detected by a sensor provided on the photoacoustic composite probe. The sensor can be a speed sensor, an acceleration sensor, a distance sensor, etc., for example, the moving speed of the photoacoustic composite probe can be directly detected by the speed sensor disposed on the photoacoustic composite probe 20; The acceleration sensor indirectly detects the moving speed of the photoacoustic composite probe 20; the distance sensor can also indirectly detect the moving speed of the photoacoustic composite probe 20 by detecting the distance change between the photoacoustic composite probe 20 and a specific reference. The type is not limited, as long as the sensor that can detect the moving speed of the photoacoustic composite probe 20 is within the protection scope of this embodiment.

The moving speed of the photoacoustic composite probe 20 is detected by the sensor. The moving speed can be the moving speed of the probe on the tissue to be measured, or the moving speed of the probe in space. Sometimes the user is moving the photoacoustic composite probe 20 from the target tissue. When moving a long distance between the two regions of the sensor, the probe is habitually lifted away from the surface of the tissue to be tested, and the probe is moved at a certain distance from the surface of the tissue to be tested. At this time, the speed of the photoacoustic composite probe 20 can still be detected by the sensor.

At the same time as the photoacoustic imaging, ultrasonic imaging can also be performed, and the moving speed of the photoacoustic composite probe 20 can be determined through the ultrasonic image. In an embodiment, the photoacoustic composite probe is used to obtain continuous multiple frames of ultrasonic images of the tissue to be tested; the moving speed of the photoacoustic composite probe on the tissue to be tested is detected by using the continuous multiple frames of ultrasonic images as The moving speed of the photoacoustic composite probe. For example, it is possible to detect image changes between consecutive multiple frames of ultrasonic images, and reflect the moving speed of the photoacoustic composite probe 20 through the image changes per unit time.

In an embodiment, the detecting the moving speed of the photoacoustic composite probe on the tissue to be tested by using the continuous multi-frame ultrasonic images includes: identifying the target area in the continuous multi-frame ultrasonic images; The position change of the target area in the ultrasound image determines the moving speed of the photoacoustic composite probe on the tissue to be measured. It can be understood that when the photoacoustic composite probe 20 moves, the tissue in the ultrasonic image formed by the photoacoustic composite probe 20 will also move correspondingly, so the target area in the ultrasonic image can be identified, and it can be recognized in consecutive multiple frames of ultrasonic images. For the target area, the moving speed of the photoacoustic composite probe 20 on the tissue to be measured is determined by calculating the position change of the target area in the multi-frame ultrasound images per unit time.

In another embodiment, the detecting the moving speed of the photoacoustic composite probe on the tissue to be measured by using the continuous multi-frame ultrasonic images includes: identifying whether the continuous multi-frame ultrasonic images include a target area; determining the continuous multi-frame ultrasonic images The multi-frame ultrasound images include the frame numbers of the continuous ultrasound images of the target area; the moving speed of the photoacoustic composite probe on the tissue to be measured is determined by the frame numbers. It can be understood that when the photoacoustic composite probe 20 moves on the tissue to be tested, a certain target area on the multiple frames of ultrasound images acquired during the movement will appear from one edge of one frame of ultrasound The multi-frame ultrasound image gradually moves to the other side until it disappears from the other side of the subsequent ultrasound image. Because the faster the photoacoustic composite probe 20 moves, the faster the process of the target area from appearing to disappearing will be, and the corresponding number of frames of the ultrasound image including the target area will be less. On the contrary, the more the photoacoustic composite probe 20 moves Slower, the slower the process of the target area from appearing to disappearing, and the correspondingly more frames of the ultrasound image containing the target area. Therefore, by identifying whether the target area is included in the consecutive multiple frames of ultrasonic images, the frame number of the consecutive ultrasonic images including the target area can be determined, and the moving speed of the photoacoustic composite probe 20 on the tissue to be tested can be determined by the frame number.

In one embodiment, identifying whether a target area is included in the continuous multiple frames of ultrasound images and determining the number of frames of the continuous ultrasound images including the target area in the continuous multiple frames of ultrasound images includes: identifying the continuous multiple frames frame by frame. Whether a frame of ultrasound image contains the target area; the count of the number of frames from the time when the target area is identified in a frame of ultrasound image, and when the target area is continuously identified in a frame of ultrasound image, the image The number of frames is accumulated for one frame until it is recognized that a frame of ultrasound image does not contain the target area, the counting of the frame number of the image is stopped, and the frame number of the image at the time of stopping is determined. The above-mentioned counting of ultrasound images can be accomplished by a counter. Identify whether the target area is included in the continuous multi-frame ultrasound images frame by frame, start counting when the target area is identified, stop counting when the target area disappears for the first time, determine the number of frames counted when it stops, and use the frame number to judge The moving speed of the photoacoustic composite probe 20 . It can be understood that, the larger the frame number, the slower the photoacoustic composite probe 20 moves, and the smaller the frame number, the faster the photoacoustic composite probe 20 moves.

When the moving speed of the photoacoustic composite probe 20 is determined by the frame number of the continuous ultrasound images including the target area, the speed of the photoacoustic composite probe 20 can be directly characterized by the frame number of the ultrasound image, or the frame rate of the ultrasound image, the ultrasound The size of the image and the frame number calculate the moving speed of the target area on the ultrasound image as the moving speed of the photoacoustic composite probe 20 .

The target area may include, but is not limited to, at least one of the following: an area where a specific anatomical structure is located, an area where the brightness meets a preset condition, and an area where the pixel gradient meets the preset condition. The specific anatomical structure can be determined according to the type of the tissue to be tested in this photoacoustic imaging, and the preset conditions of the brightness and the preset conditions of the pixel gradient can be preset by the factory or set by the user. This embodiment does not limit the type of the target area, as long as the target area can be easily identified on the ultrasound image.

Among them, the identification of the target area in the continuous multi-frame ultrasonic images can be recognized by functions such as image similarity, or by a machine learning model. In this embodiment, the identification method of the target area in the continuous multi-frame ultrasonic images is not make restrictions.

As shown in FIG. 3 , the present application provides a photoacoustic imaging method, which can determine the number of times of laser light emitted into one frame of photoacoustic image based on the moving speed of the photoacoustic composite probe, and the method can include the following steps:

Step 301, detecting the moving speed of the photoacoustic composite probe;

In the process of photoacoustic imaging, the user holds the photoacoustic composite probe 20 and places it on the surface of the tissue to be tested. The photoacoustic composite probe 20 emits laser light to the tissue to be tested, and receives ultrasonic waves generated by the tissue to be tested under the action of the laser. The composite probe 20 converts the received ultrasonic waves into photoacoustic electrical signals, and the photoacoustic signals are further used for subsequent processing to obtain a photoacoustic image, and the user observes the photoacoustic image for evaluating the health status of the tissue to be tested.

According to clinical needs, the user often moves the photoacoustic composite probe 20 slowly or keeps the photoacoustic composite probe 20 still to observe the photoacoustic image of the region in detail, while for the non-focus region, the user often moves quickly The photoacoustic composite probe 20 is swept away, or between two areas of focus, the user holds the photoacoustic composite probe 20 and moves quickly to switch between the two areas of focus. During this process, when the user moves the photoacoustic composite probe 20 slowly or keeps the photoacoustic composite probe 20 still, the doctor needs to carefully observe the photoacoustic image of the area, and the user has high requirements on the image quality of the photoacoustic image; When the user moves the photoacoustic composite probe 20 rapidly, the user does not need to observe the photoacoustic image of the moving area in detail, but often needs to observe the corresponding photoacoustic image in time at each position during the rapid movement. , the user does not have high requirements on the image quality of the photoacoustic image, but the frame rate of the photoacoustic imaging needs to be large enough to match the moving speed of the photoacoustic composite probe 20 . Based on this requirement, the moving speed of the photoacoustic composite probe 20 can be detected by the processor 70 , and the subsequent photoacoustic imaging process can be controlled by the moving speed of the photoacoustic composite probe 20 .

Step 302, determining the number of times N of laser emission based on the moving speed;

The processor 70 determines the number N of laser emission based on the moving speed of the photoacoustic composite probe 20 determined in step 301 . It can be understood that the number of laser firings N can be adaptively changed with the change of the moving speed of the photoacoustic composite probe 20, so that under different moving speeds of the photoacoustic composite probe 20, the number of laser firings can be adapted to the user's perception of the photoacoustic. image request. It can be understood that the number N of laser emission can be any integer greater than or equal to 1.

In an embodiment, the number of laser emission N may be determined based on the moving speed and a preset corresponding relationship, wherein the preset corresponding relationship is the corresponding relationship between the moving speed of the photoacoustic composite probe and the number of laser emission N, and the corresponding relationship is The relationship is negatively correlated. The preset corresponding relationship can be a functional relationship between the moving speed of the photoacoustic composite probe 20 and the number of laser emission N. When the moving speed of the photoacoustic composite probe 20 is known, the corresponding laser emission number N can be calculated through the functional relationship. The preset correspondence can also be other correspondences between the moving speed of the photoacoustic composite probe 20 and the number of laser emission N, for example, when the moving speed of the photoacoustic composite probe 20 is known, the corresponding laser can be determined by looking up a table. Number of shots N. The corresponding relationship in this embodiment may be a negative correlation, that is, the greater the moving speed of the photoacoustic composite probe 20, the smaller the corresponding number of laser emission times N; the smaller the moving speed of the photoacoustic composite probe 20, the corresponding number of laser emission times The larger N is; in order to meet the requirements for a higher imaging frame rate when the user moves the photoacoustic composite probe 20 quickly, and when the user moves the photoacoustic composite probe 20 slowly or keeps the photoacoustic composite probe 20 still, the comparison High image quality requirements. The specific negative correlation between the moving speed of the photoacoustic composite probe 20 and the number of laser emission N can be preset at the factory, or can be set by the user according to clinical needs. Further, the determined laser emission times can also be displayed on the display 80 , and the detected moving speed of the photoacoustic composite probe 20 can also be displayed on the display 80 .

In an embodiment, the preset corresponding relationship may be the corresponding relationship between the moving speed gear of the photoacoustic composite probe 20 and the number of laser emission N, for example, the moving speed of the photoacoustic composite probe 20 can be divided into: fast, medium speed and There are three slow speed gears, each of which represents an interval of the moving speed of the probe, and each gear corresponds to a number of laser emission N. For example, when the current moving speed of the photoacoustic composite probe 20 falls into the slow gear, the number N of laser firings is determined to be 10 according to the preset correspondence; when the current moving speed of the photoacoustic composite probe 20 falls into the medium gear , the number N of laser emission is determined to be 5 times according to the preset correspondence; when the current moving speed of the photoacoustic composite probe 20 falls into the fast gear, the number of laser emission N is determined to be 1 according to the preset correspondence. Further, the speed gear corresponding to the moving speed of the photoacoustic composite probe 20 can also be displayed on the display 80 , and the corresponding laser emission times can also be displayed on the display 80 .

Step 303, controlling the photoacoustic composite probe to emit laser N times to the tissue to be tested;

The processor 70 controls the photoacoustic composite probe 20 to emit N times of laser light to the tissue to be tested, and the process from the laser 90 emitting laser light to the stop of emitting laser light under the one-time firing instruction of the timing controller is that the photoacoustic composite probe 20 emits 1 laser light to the tissue to be tested. Repeating the process N times, the photoacoustic composite probe 20 emits N times of laser light to the tissue to be measured, and the N times of laser emission will be used to obtain a frame of photoacoustic image subsequently.

Step 304, control the photoacoustic composite probe to respectively receive N times of ultrasonic waves generated by the tissue to be tested under the action of the N times of laser light, to obtain N photoacoustic electrical signals, wherein the tissue to be tested is emitted in one transmission. The ultrasonic wave generated under the action of the laser is an ultrasonic wave, and the photoacoustic electrical signal obtained by receiving an ultrasonic wave is a photoacoustic electrical signal;

The processor 70 controls the photoacoustic composite probe 20 to receive N times of ultrasonic waves generated by the tissue to be tested under the action of the N lasers, so as to obtain N photoacoustic electrical signals. The ultrasonic wave generated by the tissue to be tested under the action of the laser emitted once is an ultrasonic wave. This process can be that the photoacoustic composite probe 20 emits a laser to the tissue to be tested once, and receives an ultrasonic wave generated by the tissue to be tested under the action of the laser. The photoacoustic composite probe 20 converts the primary ultrasonic wave into a photoacoustic electrical signal, and repeats this process N times to obtain N photoacoustic electrical signals.

Step 305, processing the N photoacoustic electrical signals to obtain a frame of photoacoustic image.

Processing the N photoacoustic electrical signals to obtain a frame of photoacoustic images, which can be obtained by processing the N photoacoustic electrical signals through an analog-to-digital conversion module, a beamforming module and a processor to obtain a frame of photoacoustic images, not limited to analog-to-digital conversion The module, the beam synthesis module and the processor may also include other processing modules in the process of processing the photoacoustic electrical signal to obtain a frame of photoacoustic image, which is not limited in this embodiment.

It can be understood that the more photoacoustic electrical signals are processed to obtain a frame of photoacoustic image, the higher the image quality of the photoacoustic image. The more time it takes to transmit, the lower the imaging frame rate at this time. On the contrary, the fewer photoacoustic signals are processed to obtain a frame of photoacoustic images, for example, one frame is obtained by processing one photoacoustic signal. For photoacoustic images, one frame of photoacoustic image can be obtained by one laser emission, so the imaging frame rate is high at this time, but also because one laser emission is one frame of photoacoustic image, the photoacoustic image of this frame is affected by this laser emission. And the influence of ultrasonic reception is great, and some random noise cannot be removed, so that the quality of the photoacoustic image of this frame is not as high as that of a frame of photoacoustic image formed by multiple laser emission. Since the characteristics of a frame of photoacoustic images formed by different firing times are different, they can be matched according to the needs of clinicians. In this embodiment, the moving speed of the photoacoustic composite probe 20 is negatively correlated with the number N of laser firings. When the doctor moves the photoacoustic composite probe 20 quickly, he needs to pay attention to the rapidly changing photoacoustic images and does not have high requirements on the quality of the images. Therefore, when the photoacoustic composite probe 20 moves fast, it is determined that the number of laser firings N is small. One or two lasers can form one frame of photoacoustic image, so it can meet the imaging frame rate requirement when the doctor moves the photoacoustic composite probe 20 quickly. When the doctor moves the photoacoustic composite probe 20 slowly or keeps the photoacoustic composite probe 20 still, the doctor needs to focus on checking the photoacoustic image of the area of the tissue to be tested. The acoustic composite probe 20 moves slowly or remains stationary, and the imaging area of the photoacoustic composite probe 20 changes slowly or is inconvenient. At this time, the update speed of the photoacoustic image is not required to be high, even if a lower imaging frame rate can be used, it will not affect the According to the user's observation, when the photoacoustic composite probe 20 moves slowly, it is determined that the number of laser emission N is relatively large, for example, 10 times of laser is emitted to form a photoacoustic image, which can meet the doctor's requirements for photoacoustic image quality.

In an embodiment, the N photoacoustic electrical signals can be converted into N photoacoustic digital signals by analog-to-digital conversion; the N photoacoustic digital signals are averaged to obtain an average photoacoustic digital signal; The average photoacoustic digitized signal is subjected to beam synthesis to obtain a target photoacoustic image signal; the target photoacoustic image signal is processed to obtain a frame of photoacoustic image.

The photoacoustic composite probe 20 emits N times of laser light to the tissue to be tested, and the tissue to be tested generates N times of ultrasonic waves under the action of the laser. Further, by converting the N photoacoustic electrical signals into N ultrasonic digitized signals through the analog-to-digital conversion module, a photoacoustic electrical signal can be obtained for one laser emission, and the photoacoustic electrical signal is converted into an ultrasonic digitized signal. The N photoacoustic electrical signals can be converted into N ultrasonic digitized signals respectively; it is also possible to obtain a photoacoustic electrical signal for one laser emission, and after obtaining the N photoacoustic electrical signals, the N photoacoustic electrical signals can be converted together is the N ultrasound digitized signals. The N photoacoustic digitized signals are averaged to obtain an average photoacoustic digitized signal. Further, the average photoacoustic digitized signal is subjected to beam synthesis to obtain a target photoacoustic image signal, and the target photoacoustic image signal is processed to obtain a frame of photoacoustic image. image. It can be understood that when the value of the number of laser emission N is larger, the more photoacoustic digitized signals will be averaged, and the more photoacoustic digitized signals will be averaged, then the random noise in a single photoacoustic digitized signal will The smaller the influence of the photoacoustic image, the higher the quality of the photoacoustic image, but the imaging frame rate of the corresponding photoacoustic image will also decrease accordingly.

When the moving speed of the photoacoustic composite probe 20 is relatively slow, the number of times N of laser emission is relatively large, for example, ten times. The photoacoustic composite probe 20 emits laser ten times to the tissue to be tested to obtain ten photoacoustic electrical signals. The ten photoacoustic electrical signals are converted into ten photoacoustic digital signals after analog-to-digital conversion, and the ten photoacoustic digital signals are averaged Finally, random noise at random positions in a single photoacoustic digitized signal can be overcome, and the quality of the average photoacoustic digitized signal is higher than that of a single photoacoustic digitized signal. Further, beam synthesis is performed on the average photoacoustic digitized signal to obtain the target photoacoustic image signal, and the target photoacoustic image signal is processed to obtain a frame of photoacoustic image. The signal-to-noise ratio of the photoacoustic image is higher than that of the photoacoustic image converted from a single photoacoustic digitized signal, and because the far-field noise in the photoacoustic image is weakened after being averaged by multiple signals, the far-field image is clearer. In contrast, the imaging depth of the image can be improved, and the user's requirements for photoacoustic image quality when moving the photoacoustic composite probe 20 slowly or keeping the photoacoustic composite probe 20 stationary can be met.

However, when the moving speed of the photoacoustic composite probe 20 is fast, the number of laser emission N is small, for example, once, the photoacoustic composite probe 20 emits a laser to the tissue to be measured once, and obtains a photoacoustic electrical signal, which is a photoacoustic electrical signal. After the signal is converted by analog-digital, a photoacoustic digitized signal is obtained, and the average of a photoacoustic digitized signal can be considered to obtain the photoacoustic digitized signal itself. Further, a photoacoustic digitized signal is beam synthesized to obtain the target photoacoustic signal. Image signal, process the target photoacoustic image signal, and obtain a frame of photoacoustic image. At this time, one frame of photoacoustic image can be obtained with one laser emission, and the imaging frame rate is relatively high, which can meet the requirements of the user that the photoacoustic image can display the photoacoustic image of the area covered by the probe in time when the photoacoustic composite probe 20 is rapidly moved. . However, because one frame of photoacoustic image obtained by one laser emission is greatly affected by the quality of the photoacoustic digitized signal obtained by one laser emission, the random noise at random positions in the one photoacoustic digitized signal cannot be processed by multiple photoacoustic digitized signals. The signal is averaged to reduce the impact, so the quality of the photoacoustic image is lower than that of the photoacoustic image when the number of laser emission N is large, but the user does not need to carefully observe each frame of the photoacoustic image, so at this time the photoacoustic image The quality can meet the needs of users.

It should be noted that the averaging of the N photoacoustic digitized signals may be the averaging of the signals at any processing stage after the analog-to-digital conversion to the beam synthesis, and then the obtained averaged photoacoustic digitized signals can be directly beam synthesized. The obtained average photoacoustic digitized signal can also be subjected to other processing steps before beam synthesis. The beam synthesized signal is the target photoacoustic image signal, and a frame of photoacoustic image can be obtained by processing the target photoacoustic image signal.

In one embodiment, the N photoacoustic electrical signals can be converted into N photoacoustic digital signals by analog-to-digital conversion; the N photoacoustic digital signals can be beam synthesized to obtain N photoacoustic image signals; The N photoacoustic image signals are averaged to obtain an average photoacoustic image signal; the average photoacoustic image signal is processed to obtain a frame of photoacoustic image.

The photoacoustic composite probe 20 emits N times of laser light to the tissue to be tested, and the tissue to be tested generates N times of ultrasonic waves under the action of the laser. Perform analog-to-digital conversion on the N photoacoustic electrical signals to obtain N photoacoustic digitized signals, and perform beam synthesis on the N photoacoustic digitized signals to obtain N photoacoustic image signals. Similar to the above embodiment, the beam here The synthesis process may be that each time a photoacoustic digitized signal is generated, beam synthesis is performed to obtain a photoacoustic image signal, and the N photoacoustic digitized signals are respectively beam synthesized to obtain N photoacoustic image signals; After the photoacoustic digitized signals, the N photoacoustic digitized signals are converted into N photoacoustic image signals together. The N photoacoustic image signals are averaged to obtain an average photoacoustic image signal, and further, the average photoacoustic image signal is processed to obtain a frame of photoacoustic image. It can be understood that when the value of the number of laser emission N is larger, the more photoacoustic image signals will be averaged, and the more photoacoustic image signals will be averaged, the random noise in a single photoacoustic image signal will The smaller the influence of the photoacoustic image, the higher the quality of the photoacoustic image, but the imaging frame rate of the corresponding photoacoustic image will also decrease accordingly.

When the moving speed of the photoacoustic composite probe 20 is relatively slow, the number of times N of laser emission is relatively large, for example, ten times. The photoacoustic composite probe 20 emits laser ten times to the tissue to be tested to obtain ten photoacoustic electrical signals. The ten photoacoustic electrical signals are converted into ten photoacoustic digital signals after analog-to-digital conversion, and the ten photoacoustic digital signals are processed. Ten photoacoustic image signals are obtained by beam synthesis. After averaging the ten photoacoustic image signals, random noise at random positions in a single photoacoustic image signal can be overcome, and the quality of the average photoacoustic image signal is better than that of a single photoacoustic image signal. High quality. Further, the average photoacoustic image signal is processed to obtain a frame of photoacoustic image. Since the quality of the average photoacoustic image signal is high at this time, the signal-to-noise ratio of the obtained photoacoustic image is relative to that of a single photoacoustic digitized signal. The signal-to-noise ratio of the photoacoustic image is high, and since the far-field noise in the photoacoustic image is weakened after being averaged by multiple signals, the far-field image is clearer. Requirements for photoacoustic image quality when moving the photoacoustic composite probe 20 or keeping the photoacoustic composite probe 20 stationary.

However, when the moving speed of the photoacoustic composite probe 20 is fast, the number of times N of laser emission is small, for example, twice, the photoacoustic composite probe 20 emits the laser twice to the tissue to be measured, and two photoacoustic electrical signals are obtained. Two photoacoustic digital signals are obtained after analog-to-digital conversion of the two photoacoustic electrical signals. The two photoacoustic digital signals are beam-synthesized to obtain two photoacoustic image signals. After averaging the two photoacoustic image signals, the average optical signal is obtained. Acoustic image signal, process the average photoacoustic image signal to obtain a frame of photoacoustic image. At this time, one frame of photoacoustic image can be obtained by emitting two lasers, and the imaging frame rate is high, which can meet the requirement of the user that the photoacoustic image can display the photoacoustic image of the area covered by the probe in time when the photoacoustic composite probe 20 is moved rapidly. Require. However, since a frame of photoacoustic image is obtained by two laser emission, the quality of the photoacoustic image signal obtained by the two laser emission is greatly affected, and the random noise of random position in the two photoacoustic image signals cannot pass through multiple The average of the photoacoustic image signals reduces the influence, so the quality of the photoacoustic image at this time is lower than that of the photoacoustic image when the number of laser emission N is large, but the user does not need to observe each frame of the photoacoustic image carefully, so this The quality of time and sound images can meet the needs of users.

It should be noted that the averaging of the N photoacoustic image signals may be the averaging of the signals at any processing stage after beam synthesis to the output of the photoacoustic image, and the obtained averaged photoacoustic image signals can be directly processed subsequently to obtain A photoacoustic image can also be processed to obtain a frame of photoacoustic image after performing other processing on the obtained average photoacoustic image signal.

According to the frame rate and image quality requirements of clinical photoacoustic imaging, the number of laser emission N can be greater than or equal to 1 and less than or equal to 15. For example, when the photoacoustic composite probe 20 moves very fast, the number of laser emission N can be 1; when the photoacoustic composite probe 20 remains stationary, the laser emission number N can be 15; when the photoacoustic composite probe 20 moves at a moderate speed , the number N of laser emission can be 8. The specific value of the number of laser emission N can be determined according to the moving speed of the photoacoustic composite probe 20, and the value range of the number of laser emission N can be preset by the factory, or can be set according to user requirements.

The detection of the moving speed of the photoacoustic composite probe in step 301 can be realized by arranging a sensor on the photoacoustic composite probe 20, or it can be realized by detecting an ultrasonic image.

In one embodiment, a sensor may be provided on the photoacoustic composite probe 20 , and the moving speed of the photoacoustic composite probe 20 may be detected by the sensor provided on the photoacoustic composite probe 20 . The sensor may be a velocity sensor, an acceleration sensor, or a position sensor, etc., as long as the sensor can detect the moving speed of the photoacoustic composite probe 20, and the application does not limit the type of the sensor.

In one embodiment, the photoacoustic composite probe is used to obtain continuous multiple frames of ultrasonic images of the tissue to be tested; the moving speed of the photoacoustic composite probe on the tissue to be tested is detected by the continuous multiple ultrasonic images as the moving speed of the photoacoustic composite probe.

In an implementation manner, the moving speed of the photoacoustic composite probe on the tissue to be tested is detected by using continuous multiple frames of ultrasound images, and the target area in the continuous multiple frames of ultrasound images can be identified; The change in position determines the speed at which the photoacoustic composite probe moves on the tissue to be measured.

In another implementation manner, the moving speed of the photoacoustic composite probe on the tissue to be tested can be detected by using continuous multiple frames of ultrasound images, and whether the continuous multiple frames of ultrasound images contain a target area can be identified; The number of frames of continuous ultrasound images of the area; the moving speed of the photoacoustic composite probe on the tissue to be tested is determined by the number of frames.

Specifically, identifying whether the continuous multiple frames of ultrasound images include the target area and determining the number of frames of the continuous ultrasound images including the target area in the continuous multiple frames of ultrasound images can identify whether the continuous multiple frames of ultrasound images include the target area by frame by frame; Counting the number of frames of the image when it is recognized that a frame of ultrasound image contains the target area, and each time a frame of ultrasound image is continuously recognized to contain the target area, the number of frames of the image is accumulated to one frame, until it is recognized that there is no image in a frame of ultrasound image. When the target area is included, the count of the number of frames of the image is stopped, and the number of frames of the image at the time of stop is determined.

Wherein, the target area may include at least one of the following: the area where the specific anatomical structure is located, the area where the brightness meets the preset condition, and the area where the pixel gradient meets the preset condition.

For the method of detecting the moving speed of the photoacoustic composite probe 20, reference may be made to the above discussion, which will not be repeated here.

As shown in FIG. 4 , the present application provides a photoacoustic imaging method, which can determine whether to emit laser light for photoacoustic imaging based on the moving speed of the photoacoustic composite probe. The method may include the following steps:

Step 401, detecting the moving speed of the photoacoustic composite probe;

The processor 70 detects the moving speed of the photoacoustic coincidence probe, so as to instruct whether to emit laser light subsequently to obtain the photoacoustic image. During the photoacoustic imaging process, the user holds the photoacoustic composite probe 20 and places it on the scanning area on the surface of the tissue to be measured. The next scanning area of the tissue moves quickly. When the user moves the photoacoustic composite probe 20 to the next scanning area of the tissue to be tested, the user keeps the photoacoustic composite probe 20 in the next scanning area of the tissue to be tested. Move or move slowly for photoacoustic imaging. In the above process, the user often only pays attention to the photoacoustic image of the scanning area of the tissue to be tested, and the process of moving the probe quickly is often only to move from one scanning area to another, so the user does not pay attention to the moving process The photoacoustic image in the moving process, or the image quality of the photoacoustic image in the moving process is not high. Therefore, according to the moving speed of the probe, it can be determined whether to emit laser light to generate a photoacoustic image.

For the method of detecting the moving speed of the photoacoustic composite probe 20, reference may be made to the above discussion, which will not be repeated here.

Step 402, when the moving speed satisfies the first preset condition, control the photoacoustic composite probe not to emit laser light to the tissue to be tested;

When the processor determines that the moving speed of the photoacoustic composite probe 20 satisfies the first preset condition, it controls the photoacoustic composite probe 20 not to emit laser light to the tissue to be measured. The first preset condition can be set based on clinical needs. When the moving speed of the photoacoustic composite probe 20 satisfies this condition, there is no need to emit laser light to the tissue to be measured, and the user does not need to perform photoacoustic imaging at this time.

In an embodiment, the first preset condition is that the moving speed is greater than or equal to a second preset threshold. When the moving speed of the photoacoustic composite probe 20 is too fast, the user often moves the photoacoustic composite probe 20 from one scanning area of the tissue to be tested to another scanning area, and the user generally only pays attention to the two scanning areas. Photoacoustic images, but do not pay attention to the photoacoustic images of the areas passing through during the movement process, the user often only needs to move the photoacoustic composite probe 20 from one scanning area to another scanning area as soon as possible. The moving speed of the acoustic composite probe 20 determines the user's intention. The user's intention can be determined by setting a second preset threshold. When the speed of the user moving the photoacoustic composite probe 20 is greater than or equal to the second preset threshold, it can be seen that the user is in the process of switching between the two scanning areas. , or the user may have shaken the photoacoustic composite probe 20 due to negligence, therefore, the photoacoustic composite probe 20 can be controlled not to emit laser light to the tissue to be measured, so as to reduce the amount of laser light incident on the tissue to be measured and ensure the smoothness of the photoacoustic imaging process. It is safe, and the user does not pay attention to the photoacoustic image at this time, and does not emit laser light for photoacoustic imaging, which can reduce the amount of calculation of the device and improve the subsequent running speed.

The second preset threshold here may be set based on the user's operating habits, may be preset by the factory, or may be set by the user.

Step 403, when the moving speed satisfies the second preset condition, control the photoacoustic composite probe to emit laser light to the tissue to be tested, and control the photoacoustic composite probe to receive the tissue to be tested under the action of the laser light. The generated ultrasonic wave is used to obtain a photoacoustic electrical signal, and the photoacoustic electrical signal is processed to obtain a photoacoustic image.

When the processor determines that the moving speed of the photoacoustic composite probe 20 satisfies the second preset condition, it controls the photoacoustic composite probe 20 to emit laser light to the tissue to be tested, and based on the photoacoustic electrical signal obtained by the ultrasonic wave generated by the tissue to be tested under the action of the laser , and further processed to obtain a photoacoustic image. When the moving speed of the photoacoustic composite probe 20 satisfies the second preset condition, the photoacoustic composite probe 20 can be controlled to emit laser light to the tissue to be tested once, or the photoacoustic composite probe 20 can be controlled to emit laser light at least twice to the tissue to be tested. And obtain one photoacoustic electrical signal or at least two photoacoustic electrical signals, and further generate one frame of photoacoustic image or multiple frames of photoacoustic images based on the one photoacoustic electrical signal or at least two photoacoustic electrical signals. The second preset condition can be set based on clinical needs. When the moving speed of the photoacoustic composite probe 20 satisfies this condition, it can be inferred that the user needs to obtain a photoacoustic image of the area of the tissue to be tested for observation. The composite probe 20 emits laser light to the tissue to be measured to obtain a photoacoustic image.

In one embodiment, the second preset condition is that the moving speed is less than the second preset threshold. When the moving speed of the photoacoustic composite probe 20 is slow or the photoacoustic composite probe 20 remains stationary, the user often needs to carefully observe the photoacoustic image of the area of the tissue to be tested, and in this case, the laser needs to be emitted and photoacoustic imaging is performed. The intention of the user can be determined by setting a second threshold. When the speed of the user moving the photoacoustic composite probe 20 is less than the second threshold, it can be seen that the user needs to observe the photoacoustic image in the area where the photoacoustic composite probe 20 is located. Therefore, The photoacoustic composite probe 20 can be controlled to emit laser light to the tissue to be measured, so as to obtain a photoacoustic image. Through the setting of the second preset threshold, when the user needs to observe the photoacoustic image, the photoacoustic image is obtained by emitting a laser for photoacoustic imaging for the user to observe, which satisfies the user's needs, and when the user does not need to observe the photoacoustic image, No laser is emitted and no photoacoustic imaging is performed, which saves the amount of computation and improves safety.

Further, when the moving speed of the photoacoustic composite probe 20 satisfies the second preset condition, the number of laser emission N can also be determined based on the moving speed; the photoacoustic composite probe is controlled to emit N times of laser light to the tissue to be tested. ; Control the photoacoustic composite probe to receive the N times ultrasonic waves generated by the tissue to be tested under the action of the N times of laser light to obtain N photoacoustic electrical signals, wherein the tissue to be tested is under the action of a laser emitted once The ultrasonic wave generated in the next step is an ultrasonic wave, and the photoacoustic electric signal obtained by receiving the ultrasonic wave once is a photoacoustic electric signal; a frame of photoacoustic image is obtained by processing the N photoacoustic electric signals. When the moving speed satisfies the second preset condition, it can be inferred that the user needs to observe the photoacoustic image, but in different situations, the user's requirements for the frame rate and image quality of the photoacoustic image are also different. In the case of the second preset condition, the number of times N of laser emission required to form one frame of photoacoustic image is further determined by the moving speed. When the moving speed of the photoacoustic composite probe 20 indicates that the user needs a high-quality photoacoustic image, but the imaging frame rate is not high, the number of laser emission N can be larger, so that the laser is emitted more times to form a frame of photoacoustic image , which improves the quality of the photoacoustic image. When the moving speed of the photoacoustic composite probe 20 indicates that the user needs a higher update speed of the photoacoustic image, but the quality of the photoacoustic image is not high, the number of laser emission N can be smaller, so that the laser emitted less times is One frame of photoacoustic image can be obtained, which improves the frame rate of photoacoustic imaging.

In an embodiment, the number of laser emission N may be determined based on the moving speed and a preset corresponding relationship, wherein the preset corresponding relationship is the corresponding relationship between the moving speed of the photoacoustic composite probe and the number of laser emission N, and the corresponding relationship is The relationship is negatively correlated. That is to say, the higher the moving speed of the photoacoustic composite probe 20, the smaller the corresponding number of laser emission times N; the smaller the moving speed of the photoacoustic composite probe 20, the larger the corresponding number of laser emission times N; The requirements for higher imaging frame rate when moving the photoacoustic composite probe 20 and the requirements for higher image quality when the user moves the photoacoustic composite probe 20 slowly or keeps the photoacoustic composite probe 20 still.

The technical features associated with the various embodiments described above, unless otherwise specified, can be applied in other embodiments. For the description of the associated technical features, reference may be made to the associated embodiments, and the repeated parts will not be repeated. Repeat.

As shown in FIG. 1 , the present application further provides a photoacoustic imaging system, which can be used to execute the photoacoustic imaging methods of the above embodiments, the photoacoustic imaging system includes: a laser, a photoacoustic composite probe, and a processor;

The laser is used to generate laser light and emit the laser light to the target tissue through the optical transmission device;

The photoacoustic composite probe is used for receiving the photoacoustic signal returned from the target tissue;

The processor is configured to process the photoacoustic signal to obtain a photoacoustic image;

The processor may be used to execute the methods described in the above embodiments.

In addition, according to an embodiment of the present application, a storage medium is also provided, and program instructions are stored on the storage medium, and the program instructions are used to execute the photoacoustic imaging of the embodiments of the present application when the program instructions are run by a computer or a processor. corresponding steps of the method. The storage medium may include, for example, a memory card of a smartphone, a storage component of a tablet computer, a hard disk of a personal computer, read only memory (ROM), erasable programmable read only memory (EPROM), portable compact disk read only memory (CD-ROM), USB memory, or any combination of the above storage media.

It should be emphasized that the photoacoustic composite probe 20 is controlled not to emit laser light to the tissue to be tested, the photoacoustic composite probe 20 is controlled to emit laser light to the tissue to be tested, and the photoacoustic composite probe 20 is controlled to emit laser light and control light to the tissue to be tested at least twice. The acoustic composite probe 20 emits laser light for N times to the tissue to be measured, which can be controlled to not emit laser light or emit laser light for corresponding times. It can be understood that if the laser emits laser light, the laser light emitted by the laser is incident from the photoacoustic composite probe 20 to the tissue to be measured through the optical transmission device, which can be regarded as the photoacoustic composite probe 20 emitting laser light to the tissue to be tested. Therefore, the present application The control of the photoacoustic composite probe 20 to emit laser light to the tissue to be tested also includes controlling the laser to emit laser light and to emit the laser light to the tissue to be tested through the photoacoustic composite probe 20 . In the same way, if the laser does not emit laser light, the photoacoustic composite probe does not emit laser light either. Therefore, the control of the photoacoustic composite probe 20 described in this application not to emit laser light to the tissue to be measured also includes controlling the laser not to emit laser light, so that the light The acoustic composite probe 20 also does not emit laser light to the tissue to be measured.

It should be noted that the embodiments of the present application are not limited to photoacoustic imaging for humans, and can also be used for photoacoustic imaging of animals.

Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above-described example embodiments are exemplary only, and are not intended to limit the scope of the application thereto. Various changes and modifications may be made therein by those of ordinary skill in the art without departing from the scope and spirit of the present application. All such changes and modifications are intended to be included within the scope of this application as claimed in the appended claims.

Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of this application.

In the several embodiments provided in this application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or May be integrated into another device, or some features may be omitted, or not implemented.

In the description provided herein, numerous specific details are set forth. It will be understood, however, that the embodiments of the present application may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

Similarly, it is to be understood that in the description of the exemplary embodiments of the present application, various features of the present application are sometimes grouped together into a single embodiment, FIG. , or in its description. However, this method of application should not be construed as reflecting an intention that the claimed application requires more features than are expressly recited in each claim. Rather, as the corresponding claims reflect, the invention lies in the fact that the corresponding technical problem may be solved with less than all features of a single disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this application.

It will be understood by those skilled in the art that all features disclosed in this specification (including the accompanying claims, abstract and drawings) and any method or apparatus so disclosed may be used in any combination, except that the features are mutually exclusive. Processes or units are combined. Each feature disclosed in this specification (including accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

Furthermore, those skilled in the art will appreciate that although some of the embodiments described herein include certain features, but not others, included in other embodiments, that combinations of features of different embodiments are intended to be within the scope of the present application within and form different embodiments. For example, in the claims, any of the claimed embodiments may be used in any combination.

Various component embodiments of the present application may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art should understand that a microprocessor or a digital signal processor (DSP) may be used in practice to implement some or all functions of some modules in the article analysis device according to the embodiments of the present application. The present application may also be implemented as a breast machine program (eg, computer program and computer program product) for performing part or all of the methods described herein. Such a program implementing the present application may be stored on a computer-readable medium, or may be in the form of one or more signals. Such signals may be downloaded from Internet sites, or provided on carrier signals, or in any other form.

It should be noted that the above-described embodiments illustrate rather than limit the application, and alternative embodiments may be devised by those skilled in the art without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The application can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In a unit claim enumerating several breast machines, several of these breast machines can be embodied by one and the same item of hardware. The use of the words first, second, and third, etc. do not denote any order. These words can be interpreted as names.

The above are only specific embodiments of the present application or descriptions of the specific embodiments, and the protection scope of the present application is not limited thereto. Any changes or substitutions should be included within the protection scope of the present application. The protection scope of the present application shall be subject to the protection scope of the claims.

Claims (26)

1. a photoacoustic imaging method, is characterized in that, comprises: In the first photoacoustic imaging mode: Control the photoacoustic composite probe to emit a laser to the tissue to be tested; Controlling the photoacoustic composite probe to receive a primary ultrasonic wave generated by the tissue to be tested under the action of the primary laser to obtain a photoacoustic electrical signal; processing the one photoacoustic electrical signal to obtain a frame of photoacoustic image; detecting the moving speed of the photoacoustic composite probe; When the detected moving speed of the photoacoustic composite probe is less than a first preset threshold, switching from the first photoacoustic imaging mode to the second photoacoustic imaging mode; Wherein, in the second photoacoustic imaging mode: controlling the photoacoustic composite probe to emit laser light to the tissue to be tested at least twice; The photoacoustic composite probe is controlled to respectively receive at least two ultrasonic waves generated by the tissue to be tested under the action of the at least two lasers, so as to obtain at least two photoacoustic electrical signals, wherein the tissue to be tested is emitted in one emission. The ultrasonic wave generated under the action of the laser is an ultrasonic wave, and the photoacoustic electrical signal obtained by receiving an ultrasonic wave is a photoacoustic electrical signal; One frame of photoacoustic image is obtained by processing the at least two photoacoustic electrical signals. 2. The method of claim 1, wherein the detecting the moving speed of the photoacoustic composite probe comprises: The moving speed of the photoacoustic composite probe is detected by a sensor provided on the photoacoustic composite probe. 3. The method of claim 1, wherein the detecting the moving speed of the photoacoustic composite probe comprises: Acquiring continuous multi-frame ultrasound images of the tissue to be tested through the photoacoustic composite probe; The moving speed of the photoacoustic composite probe on the tissue to be measured is detected by using the continuous multi-frame ultrasonic images as the moving speed of the photoacoustic composite probe. 4. The method according to claim 3, wherein the detecting the moving speed of the photoacoustic composite probe on the tissue to be measured by using the continuous multi-frame ultrasonic images comprises: identifying target regions in the consecutive multiple frames of ultrasound images; The moving speed of the photoacoustic composite probe on the tissue to be measured is determined by the position change of the target area in the continuous multi-frame ultrasound images. 5. The method according to claim 3, wherein the detecting the moving speed of the photoacoustic composite probe on the tissue to be measured by using the continuous multi-frame ultrasonic images comprises: Identifying whether a target area is included in the consecutive multiple frames of ultrasound images; Determining the number of frames of continuous ultrasound images that include the target region in the consecutive multiple frames of ultrasound images; The moving speed of the photoacoustic composite probe on the tissue to be tested is determined by the frame number. 6. The method of claim 5, wherein identifying whether a target area is included in the consecutive multi-frame ultrasonic images and determining the number of frames of consecutive ultrasonic images including the target area in the consecutive multi-frame ultrasonic images include: Identifying whether a target area is included in the continuous multi-frame ultrasound images frame by frame; Counting of the number of image frames starts from the recognition that the target area is included in a frame of ultrasound image, and the frame number of the image is accumulated to one frame each time a frame of ultrasound image is continuously recognized to contain the target area until the target area is recognized. When the target area is not included in one frame of ultrasound image, the counting of the frame number of the image is stopped, and the frame number of the image at the time of stopping is determined. 7. The method according to any one of claims 4-6, wherein the target area includes at least one of the following: an area where a specific anatomical structure is located, an area whose brightness meets a preset condition, and a pixel gradient that meets a preset condition area. 8. The method according to any one of claims 1-7, wherein, in the second photoacoustic imaging mode, the processing of the at least two photoacoustic electrical signals to obtain a frame of photoacoustic image include: performing analog-to-digital conversion on the at least two photoacoustic electrical signals to obtain at least two photoacoustic digitized signals; averaging the at least two photoacoustic digitized signals to obtain an averaged photoacoustic digitized signal; performing beam synthesis on the average photoacoustic digitized signal to obtain a target photoacoustic image signal; The target photoacoustic image signal is processed to obtain a frame of photoacoustic image. 9 . The method according to claim 1 , wherein, in the second photoacoustic imaging mode, the processing of the at least two photoacoustic electrical signals obtains a frame of photoacoustic image. 10 . include: performing analog-to-digital conversion on the at least two photoacoustic electrical signals to obtain at least two photoacoustic digitized signals; performing beam synthesis on the at least two photoacoustic digitized signals to obtain at least two photoacoustic image signals; averaging the at least two photoacoustic image signals to obtain an averaged photoacoustic image signal; The average photoacoustic image signal is processed to obtain a frame of photoacoustic image. 10. A photoacoustic imaging method, comprising: Detect the moving speed of the photoacoustic composite probe; determining the number N of laser firings based on the moving speed; Controlling the photoacoustic composite probe to emit N times of laser light to the tissue to be tested; The photoacoustic composite probe is controlled to receive N times of ultrasonic waves generated by the tissue to be tested under the action of the N times of laser light to obtain N photoacoustic electrical signals, wherein the tissue to be tested is under the action of a laser emitted once The generated ultrasonic wave is an ultrasonic wave, and the photoacoustic electric signal obtained by receiving an ultrasonic wave is a photoacoustic electric signal; One frame of photoacoustic image is obtained by processing the N photoacoustic electrical signals. 11. The method of claim 10, wherein the detecting the moving speed of the photoacoustic composite probe in the tissue to be measured comprises: The moving speed of the photoacoustic composite probe is detected by a sensor provided on the photoacoustic composite probe. 12. The method of claim 10, wherein the detecting the moving speed of the photoacoustic composite probe comprises: Acquiring continuous multi-frame ultrasound images of the tissue to be tested through the photoacoustic composite probe; The moving speed of the photoacoustic composite probe on the tissue to be measured is detected by using the continuous multi-frame ultrasonic images as the moving speed of the photoacoustic composite probe. 13. The method according to claim 12, wherein the detecting the moving speed of the photoacoustic composite probe on the tissue to be measured by using the continuous multi-frame ultrasonic images comprises: identifying target regions in the consecutive multiple frames of ultrasound images; The moving speed of the photoacoustic composite probe on the tissue to be measured is determined by the position change of the target area in the continuous multi-frame ultrasound images. 14. The method according to claim 12, wherein the detecting the moving speed of the photoacoustic composite probe on the tissue to be measured by using the continuous multi-frame ultrasonic images comprises: Identifying whether a target area is included in the consecutive multiple frames of ultrasound images; Determining the number of frames of consecutive ultrasound images that include the target region in the consecutive multiple frames of ultrasound images; The moving speed of the photoacoustic composite probe on the tissue to be tested is determined by the frame number. 15. The method of claim 14, wherein identifying whether a target area is included in the consecutive multi-frame ultrasound images and determining the number of frames of consecutive ultrasonic images including the target area in the consecutive multi-frame ultrasonic images include: Identifying whether a target area is included in the continuous multi-frame ultrasound images frame by frame; Counting of the number of image frames starts from the recognition that the target area is included in a frame of ultrasound image, and the frame number of the image is accumulated to one frame each time a frame of ultrasound image is continuously recognized to contain the target area until the target area is recognized. When the target area is not included in one frame of ultrasound image, the counting of the frame number of the image is stopped, and the frame number of the image at the time of stopping is determined. 16. The method according to any one of claims 13-15, wherein the target area includes at least one of the following: an area where a specific anatomical structure is located, an area whose brightness meets a preset condition, and a pixel gradient that meets a preset condition area. 17. The method according to any one of claims 10-16, wherein the determining the number N of laser emission based on the moving speed comprises: The number N of laser firings is determined based on the moving speed and a preset corresponding relationship, wherein the predetermined corresponding relationship is a corresponding relationship between the moving speed of the photoacoustic composite probe and the number of laser firings N, and the corresponding relationship is a negative correlation. 18 . The method according to claim 10 , wherein the number of times N of laser emission is greater than or equal to 1 and less than or equal to 15. 19 . 19. The method according to any one of claims 10-18, wherein the processing of the N photoacoustic signals to obtain one frame of photoacoustic images comprises: performing analog-to-digital conversion on the N photoacoustic electrical signals to obtain N photoacoustic digitized signals; averaging the N photoacoustic digitized signals to obtain an average photoacoustic digitized signal; performing beam synthesis on the average photoacoustic digitized signal to obtain a target photoacoustic image signal; The target photoacoustic image signal is processed to obtain a frame of photoacoustic image. 20. The method according to any one of claims 10-18, wherein the processing of the N photoacoustic signals to obtain one frame of photoacoustic images comprises: performing analog-to-digital conversion on the N photoacoustic electrical signals to obtain N photoacoustic digitized signals; performing beam synthesis on the N photoacoustic digitized signals to obtain N photoacoustic image signals; averaging the N photoacoustic image signals to obtain an average photoacoustic image signal; The average photoacoustic image signal is processed to obtain a frame of photoacoustic image. 21. A photoacoustic imaging method, comprising: Detect the moving speed of the photoacoustic composite probe; When the moving speed satisfies the first preset condition, controlling the photoacoustic composite probe not to emit laser light to the tissue to be measured; When the moving speed satisfies the second preset condition, the photoacoustic composite probe is controlled to emit laser light to the tissue to be tested, and the photoacoustic composite probe is controlled to receive ultrasonic waves generated by the tissue to be tested under the action of the laser , to obtain a photoacoustic electrical signal, and process the photoacoustic electrical signal to obtain a photoacoustic image. 22. The method of claim 21, wherein the first preset condition is that the moving speed is greater than or equal to a second preset threshold, and the second preset condition is that the moving speed is less than a predetermined threshold the second preset threshold. 23. The method of claim 21 or 22, wherein: when the moving speed satisfies a second preset condition, determining the number N of laser emission based on the moving speed; controlling the photoacoustic composite probe to emit N times of laser light to the tissue to be tested; Controlling the photoacoustic composite probe to receive N times of ultrasonic waves generated by the tissue to be tested under the action of the N times of laser light to obtain N photoacoustic electrical signals, wherein the tissue to be tested is under the action of a laser emitted once The generated ultrasonic wave is an ultrasonic wave, and the photoacoustic electric signal obtained by receiving an ultrasonic wave is a photoacoustic electric signal; One frame of photoacoustic image is obtained by processing the N photoacoustic electrical signals. 24. The method according to any one of claims 21-23, wherein the determining the number of times N of laser emission based on the moving speed comprises: The number N of laser firings is determined based on the moving speed and a preset corresponding relationship, wherein the predetermined corresponding relationship is a corresponding relationship between the moving speed of the photoacoustic composite probe and the number of laser firings N, and the corresponding relationship is a negative correlation. 25. A photoacoustic imaging system, comprising: a laser, a photoacoustic composite probe, and a processor; The laser is used to generate laser light and emit the laser light to the target tissue through the optical transmission device; The photoacoustic composite probe is used for receiving the photoacoustic signal returned from the target tissue; The processor is configured to process the photoacoustic signal to obtain a photoacoustic image; The processor is further configured to execute the method described in any one of the above 1-24. 26. A computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, is used to implement any one of claims 1-24. method described in item.

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