Photoacoustic imaging method and photoacoustic imaging system

Abstract

A photoacoustic imaging method and system are disclosed. The method includes, in a first photoacoustic imaging mode, controlling a photoacoustic composite probe to emit a laser beam once toward the tissue to be measured to obtain a frame of photoacoustic image; in a second photoacoustic imaging mode, controlling the photoacoustic composite probe to emit a laser beam at least twice toward the tissue to be measured to obtain a frame of photoacoustic image; and switching from the first photoacoustic imaging mode to the second photoacoustic imaging mode when detecting that the movement speed of the photoacoustic composite probe is less than a first preset threshold. By detecting the movement speed of the photoacoustic composite probe and determining the switch between the first photoacoustic imaging mode and the second photoacoustic imaging mode, the method satisfies the user's different photoacoustic image requirements when the photoacoustic composite probe is moved at different speeds.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and in particular to a photoacoustic imaging method and a photoacoustic imaging system. Background Art

[0002] In biophotoacoustic imaging applications, high-energy (tens of millijoules) nanosecond solid-state lasers are typically used to ensure sufficient penetration depth (greater than 3 cm). These lasers have a relatively low pulse repetition frequency (PRF), typically tens of Hz. Increasing the PRF is costly, and system power consumption, size, and noise increase exponentially. Limited by the laser's PRF, the frame rate of photoacoustic imaging is also relatively low.

[0003] To ensure the imaging frame rate, the emission strategy usually uses a single laser emission to obtain one frame of image. However, this results in a low signal-to-noise ratio (SNR) and low penetration. If the number of laser emissions per frame is increased, the imaging frame rate will be reduced. Due to these issues, the user experience is poor. Summary of the Invention

[0004] In a first aspect, the present application provides a photoacoustic imaging method, comprising:

[0005] In the first photoacoustic imaging mode, the photoacoustic composite probe is controlled to emit a laser once toward the tissue to be measured;

[0006] Controlling the photoacoustic composite probe to receive an ultrasonic wave generated by the tissue to be tested under the action of the laser once, so as to obtain a photoacoustic electrical signal;

[0007] Processing the photoacoustic electrical signal to obtain a frame of photoacoustic image;

[0008] Detecting the moving speed of the photoacoustic composite probe;

[0009] 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;

[0010] In the second photoacoustic imaging mode, controlling the photoacoustic composite probe to emit laser light at least twice toward the tissue to be measured;

[0011] Controlling the photoacoustic composite probe to respectively receive at least two ultrasonic waves generated by the tissue to be tested under the action of the at least two laser beams to obtain at least two photoacoustic electrical signals, wherein the ultrasonic wave generated by the tissue to be tested under the action of one laser beam emission is one ultrasonic wave, and the photoacoustic electrical signal obtained by receiving one ultrasonic wave is one photoacoustic electrical signal;

[0012] The at least two photoacoustic electrical signals are processed to obtain a frame of photoacoustic image.

[0013] In a second aspect of the present application, a photoacoustic imaging method is provided, comprising:

[0014] Detecting the moving speed of the photoacoustic composite probe;

[0015] Determining the number of laser shots N based on the moving speed;

[0016] Controlling the photoacoustic composite probe to emit N lasers toward the tissue to be tested;

[0017] Controlling the photoacoustic composite probe to respectively receive N ultrasonic waves generated by the tissue to be tested under the action of the N laser beams to obtain N photoacoustic electrical signals, wherein the ultrasonic wave generated by the tissue to be tested under the action of one laser beam is one ultrasonic wave, and the photoacoustic electrical signal obtained by receiving one ultrasonic wave is one photoacoustic electrical signal;

[0018] The N photoacoustic electrical signals are processed to obtain a frame of photoacoustic image.

[0019] In a third aspect of the present application, a photoacoustic imaging method is provided, comprising:

[0020] Detecting the moving speed of the photoacoustic composite probe;

[0021] When the moving speed meets a first preset condition, controlling the photoacoustic composite probe not to emit laser light toward the tissue to be measured;

[0022] When the movement speed meets the second preset condition, the photoacoustic composite probe is controlled to emit laser light to the tissue to be measured, and the photoacoustic composite probe is controlled to receive ultrasonic waves generated by the tissue to be measured under the action of the laser to obtain photoacoustic electrical signals, and the photoacoustic electrical signals are processed to obtain photoacoustic images.

[0023] In a fourth aspect of the present application, a photoacoustic imaging system is provided, comprising: a laser, a photoacoustic composite probe, and a processor;

[0024] The laser is used to generate laser light and transmit the laser light to the target tissue through the optical transmission device;

[0025] The photoacoustic composite probe is used to receive the photoacoustic signal returned from the target tissue;

[0026] The processor is used to process the photoacoustic signal to obtain a photoacoustic image;

[0027] The processor is further configured to execute the method described in any one of the first to third aspects above.

[0028] In a fifth aspect of the present application, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, they are used to implement the method described in any one of the first to third aspects.

[0029] The embodiment of the present application determines the switch between the first photoacoustic imaging mode and the second photoacoustic imaging mode by detecting the moving speed of the photoacoustic composite probe, thereby meeting the different needs of the user when moving the photoacoustic composite probe at different speeds. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of a photoacoustic imaging system according to an embodiment of the present application;

[0031] Figure 2 This is a flow chart of a photoacoustic imaging method according to an embodiment of the present application;

[0032] Figure 3 This is a flow chart of a photoacoustic imaging method according to another embodiment of the present application;

[0033] Figure 4 This is a flow chart of a photoacoustic imaging method according to another embodiment of the present application. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below by means of specific embodiments in conjunction with the accompanying drawings. Similar elements in different embodiments are numbered with associated similar elements. In the following embodiments, many detailed descriptions are provided to enable the present application to be better understood. However, those skilled in the art will readily appreciate that some of the features may be omitted in different circumstances, or may be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification. This is to avoid the core portion of the present application being overwhelmed by excessive descriptions, and for those skilled in the art, it is not necessary to describe these related operations in detail. They will fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0035] In addition, the features, operations, or characteristics described in the specification may be combined in any appropriate manner to form various embodiments. Furthermore, the steps or actions in the method description may be reordered or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various sequences in the specification and drawings are provided solely for the purpose of clearly describing a particular embodiment and are not intended to be mandatory, unless otherwise specified.

[0036] The serial numbers assigned to components herein, such as "first," "second," etc., are used solely to distinguish the objects being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" herein, unless otherwise specified, include both direct and indirect connections (couplings).

[0037] like Figure 1 FIG2 is a block diagram of a photoacoustic imaging system according to an embodiment of the present invention. 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 beamforming module 40, a display 80, and a memory 60. Of course, the imaging system 10 may also include other devices or components not shown in the figure.

[0038] Optionally, the photoacoustic imaging system can also perform ultrasonic imaging. During ultrasonic imaging, the transmitting circuit 310 can activate the photoacoustic hybrid probe 20 to transmit ultrasonic waves toward the tissue under test. After the photoacoustic hybrid probe 20 transmits the ultrasonic waves, the receiving circuit 320 can receive the ultrasonic echoes returned from the tissue under test through the photoacoustic hybrid probe 20, thereby obtaining an ultrasonic echo signal. This ultrasonic echo signal is directly or indirectly processed by the beamforming module to obtain an ultrasonic image signal, which is then sent to the processor 70. The processor 70 processes this ultrasonic image signal to obtain an ultrasonic image of the tissue under test.

[0039] The photoacoustic imaging system can perform photoacoustic imaging. During photoacoustic imaging, a laser 90 generates laser light. This laser 90 is connected to an optical transmission device, which includes optical fibers (fiber bundles), light guide arms, and other devices capable of transmitting laser light. This optical transmission device is coupled to the photoacoustic hybrid probe 20. The laser light generated by the laser 90 is transmitted toward the tissue under test through the optical transmission device coupled to the photoacoustic hybrid probe 20. The tissue under test absorbs the laser energy and generates ultrasonic waves. After emitting the laser light toward the tissue under test, the receiving circuit 320 receives the ultrasonic waves returned by the tissue under test through the photoacoustic hybrid probe 20 to obtain a photoacoustic electrical signal. This photoacoustic electrical signal is sent directly or after processing to the processor 70 to obtain a photoacoustic image of the tissue under test. The aforementioned ultrasonic and photoacoustic images can be stored in the memory 60 or displayed on the display 80.

[0040] In one embodiment of the present application, the photoacoustic imaging system may have only a photoacoustic imaging function to form a photoacoustic image; or it may have both a photoacoustic imaging function and an ultrasound imaging function to form an ultrasound image and a photoacoustic image. Furthermore, it may form a fusion image of the ultrasound image and the photoacoustic image, wherein the imaging mode of the ultrasound imaging is not limited and may be a grayscale imaging mode, a color imaging mode, a Doppler imaging mode, or an elastic imaging mode, etc.

[0041] In one embodiment of the present application, the processor 70 also includes a timing controller, which can generate a series of timing control signals according to a certain logic. On the one hand, it can be used to control the emission of ultrasonic excitation voltage and the reception of ultrasonic echo signals in ultrasonic imaging. On the other hand, it can be used to control the laser start-up of the laser and the reception of photoacoustic signals, thereby avoiding signal aliasing and interference through timing control.

[0042] It should be noted that in this embodiment, laser light is emitted toward the tissue to be measured via an optical transmission device coupled to the photoacoustic hybrid probe 20. This optical transmission device can be located outside the ultrasound probe housing to form the photoacoustic hybrid probe 20. For example, the optical transmission device can be coupled to the outside of the ultrasound probe housing and used to transmit laser light to both sides of the ultrasound probe, illuminating the tissue to be measured using a back-lighting method. The optical transmission device can also be located inside the ultrasound probe housing to form the photoacoustic hybrid probe 20. For example, the optical transmission device can be directly coupled to the ultrasound transducer and fully or partially enclosed by the housing to form a probe that integrates laser emission and ultrasound transmission and reception. In some implementations, the laser 90 can directly illuminate the tissue to be measured via the optical transmission device, and the optical transmission device is not coupled to the probe. That is, the optical transmission device and the ultrasound probe are two independent components, and the two together form the photoacoustic hybrid probe 20.

[0043] In one embodiment of the present application, the photoacoustic composite probe 20 may further include a mechanical scanner. The mechanical scanner enables the photoacoustic composite probe 20 to receive ultrasound waves from different directions and process the received ultrasound waves to obtain ultrasound images or photoacoustic images. In some implementations, the mechanical scanner may be coupled to the photoacoustic composite probe 20, thereby integrating the mechanical scanning function into the photoacoustic composite probe 20. Alternatively, the photoacoustic composite probe 20 may be mounted on the mechanical scanner, which drives the probe movement.

[0044] In one embodiment of the present application, the aforementioned display 80 may be a touch screen, liquid crystal display, etc. built into the imaging system, or it may be an independent display device such as a liquid crystal display, a television, etc. that is independent of the imaging system, or it may be a display screen on an electronic device such as a mobile phone or a tablet computer, etc.

[0045] In one embodiment of the present application, the aforementioned memory 60 may be a flash memory card, a solid-state memory, a hard disk, etc.

[0046] In one embodiment of the present application, the aforementioned processor 70 can be implemented by software, hardware, firmware, or a combination thereof, and can use circuits, single or multiple application-specific integrated circuits (ASICs), single or multiple general-purpose integrated circuits, single or multiple microprocessors, single or multiple programmable logic devices, or a combination of the aforementioned circuits or devices, or other suitable circuits or devices, so that the processor 70 can execute the corresponding steps of the imaging method in each embodiment of the present application.

[0047] The signal processing process of photoacoustic imaging is exemplarily described below with reference to the accompanying drawings.

[0048] The photoacoustic hybrid probe 20 may include an ultrasonic transducer and an optical transmission device. The ultrasonic transducer comprises a transducer (not shown) composed of multiple array elements arranged in an array format. The array elements may be arranged in a row to form a linear array, or in a two-dimensional matrix to form a planar array. The array elements may also form a convex array. The array elements are used to transmit ultrasonic beams based on excitation electrical signals or to convert received ultrasonic beams into electrical signals. Therefore, each array element can be used to convert electrical pulse signals into and from ultrasonic beams, thereby transmitting ultrasonic waves to a target area of ​​human tissue (e.g., the fetus in this embodiment). It can also be used to receive echoes of ultrasonic waves reflected from tissue, as well as receive ultrasonic waves generated by tissue under the action of laser light. The photoacoustic hybrid probe 20 in this embodiment can be a linear array probe for acquiring two-dimensional ultrasonic and photoacoustic images of the fetus, or a volumetric probe for acquiring three-dimensional ultrasonic and photoacoustic volume data of the fetus.

[0049] In this embodiment, the user moves the photoacoustic composite probe 20 to select a suitable position and angle to emit a laser to the tissue to be tested 10, and receives the ultrasonic waves generated by the tissue to be tested 10 under the action of the laser, obtains and outputs the photoacoustic electrical signal converted from the ultrasonic waves. 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.

[0050] The receiving circuit 320 is used to receive photoacoustic electrical signals from the photoacoustic hybrid probe 20 and process the ultrasonic echo electrical signals. The receiving circuit 320 may include one or more amplifiers, analog-to-digital converters (ADCs), and other components. The amplifier is used to amplify the received photoacoustic electrical signals after appropriate gain compensation, and the ADC is used to sample the analog echo signals at predetermined intervals to convert them into digitized photoacoustic signals. The digitized photoacoustic signals still retain amplitude, frequency, and phase information. The digitized photoacoustic signals output by the ADC module can be output to the beamforming module 40 for processing or to the memory 60 for storage.

[0051] The beamforming module 40 is signal-connected to the receiving circuit 320 and is used to perform beamforming processing, such as delay and weighted summation, on the signal output by the receiving circuit 320. Because the distances between the ultrasound receiving points in the measured tissue and the receiving elements vary, the channel data of the same receiving point output by different receiving elements have different delays. This requires delay processing, phase alignment, and weighted summation of the different channel data at the same receiving point to obtain a beamformed photoacoustic image signal. In some embodiments, the beamforming module 40 may output the photoacoustic image signal to the memory 60 for caching or storage, or directly output the photoacoustic image signal to the image processing module 720 of the processor 70 for image processing.

[0052] The beamforming module 40 may perform the aforementioned functions in hardware, firmware, or software. For example, the beamforming module 40 may include a central controller circuit (CPU), one or more microprocessor chips, or any other electronic components capable of processing input data according to specific logic instructions. When the beamforming module 40 is implemented in software, it may execute instructions stored on a tangible and non-transitory computer-readable medium (e.g., the memory 60) to perform beamforming calculations using any appropriate beamforming method.

[0053] The processor 70 is configured to be a central control unit (CPU), one or more microprocessors, a graphics controller (GPU), or any other electronic component capable of processing input data according to specific logic instructions. It can control peripheral electronic components according to input instructions or predetermined instructions, or read and / or save data from the memory 60. It can also process input data by executing programs in the memory 60. For example, according to one or more operating modes, one or more processing operations are performed on the collected photoacoustic signals. The processing operations include but are not limited to adjusting or limiting the laser emission or stopping of the laser 90, generating an ultrasound image or photoacoustic image for subsequent display on the display 80 of the human-computer interaction device, or adjusting or limiting the content and format displayed on the display 80, or adjusting one or more image display settings displayed on the display 80 (e.g., ultrasound image, interface components, and location of region of interest). The processor 70 in this embodiment can cooperate with other components to perform the photoacoustic imaging method provided by any method embodiment of the present application.

[0054] Image processing module 720 is used to process the photoacoustic image signals output by beamforming module 40 to generate a photoacoustic image that reflects the changes in signal strength within the scanning range. This photoacoustic image reflects the distribution of light-absorbing substances within human tissue. Image processing module 720 can output the photoacoustic image to display 80 of the human-computer interaction device for display.

[0055] The human-computer interaction device is used for human-computer interaction, that is, receiving user input and outputting visual information; it can receive user input using a keyboard, operation buttons, mouse, trackball, etc., or a touch screen integrated with a display; it outputs visual information using a display 80.

[0056] The memory 60 can be a tangible and non-transitory computer-readable medium, such as a flash memory card, a solid-state memory, a hard disk, etc., for storing data or programs. For example, the memory 60 can be used to store the acquired ultrasound data or image frames generated by the processor 70 that are not immediately displayed, or the memory 60 can store a graphical user interface, one or more default image display settings, and programming instructions for the processor, the beamforming module, or the IQ decoding module.

[0057] The following describes the embodiments of the photoacoustic imaging method and the photoacoustic imaging system provided in the present application in conjunction with the components of the photoacoustic imaging system.

[0058] like Figure 2 As shown, the present application provides a photoacoustic imaging method that can switch between two photoacoustic imaging modes based on the speed of the photoacoustic composite probe. The method may include the following steps:

[0059] Step 201: In a first photoacoustic imaging mode, the photoacoustic composite probe is controlled to emit a laser once toward the tissue to be measured;

[0060] In the first photoacoustic imaging mode, the processor 70 controls the photoacoustic composite probe 20 to emit a laser to the tissue to be measured. Here, one laser is the process from one emission to the stop of emission by the laser 90 under the control of the timing controller. After emitting a laser once, the photoacoustic composite probe 20 enters the stage of receiving the ultrasonic waves generated by the tissue to be measured under the action of the laser.

[0061] Step 202, controlling the photoacoustic composite probe to receive a single ultrasonic wave generated by the tissue to be tested under the action of the single laser, so as to obtain a photoacoustic electrical signal;

[0062] The processor 70 controls the photoacoustic hybrid probe 20 to receive a primary ultrasonic wave generated by the tissue under test under the action of a single laser beam, thereby obtaining a photoacoustic electrical signal. After the photoacoustic hybrid probe 20 emits a single laser beam toward the tissue under test, the tissue under test generates an ultrasonic wave under the action of the laser beam. The photoacoustic hybrid probe 20 receives the ultrasonic wave propagating from the tissue under test and converts it into a photoacoustic electrical signal for subsequent processing. The primary ultrasonic wave here refers to the portion of the ultrasonic wave generated by the tissue under test under the action of a single laser beam that is received by the photoacoustic hybrid probe 20. The photoacoustic electrical signal obtained after processing by the photoacoustic hybrid probe 20 is the primary photoacoustic electrical signal.

[0063] Step 203, processing the photoacoustic electrical signal to obtain a frame of photoacoustic image;

[0064] To process a photoacoustic electrical signal to obtain a photoacoustic image frame, the photoacoustic electrical signal can first be converted into an ultrasonic digital signal by an analog-to-digital conversion module. The ultrasonic digital signal is then processed by a beamforming module to obtain a photoacoustic image signal. The photoacoustic image signal is further processed to obtain a photoacoustic image frame, which can be presented to the user via a display 80. It should be emphasized that processing a photoacoustic electrical signal to obtain a photoacoustic image frame is not limited to the above steps, but may also include time gain compensation, IQ demodulation, and logarithmic compression. In this application, the photoacoustic electrical signal obtained by the photoacoustic composite probe 20 after analog-to-digital conversion and before entering beamforming is uniformly referred to as an ultrasonic digital signal. It is understandable that there may be many signal processing steps between the analog-to-digital conversion and the beamforming of the photoacoustic electrical signal. The ultrasonic digital signal referred to in this application may include signals at various stages from the analog-to-digital conversion to the beamforming stage. Signals at various stages from the analog-to-digital conversion to the beamforming stage are applicable to the technical solutions related to ultrasonic digital signals in various embodiments of this application. Similarly, in the present application, the signals between the ultrasound digital signals after beam synthesis and the output as photoacoustic images are uniformly referred to as photoacoustic image signals. The photoacoustic image signals can be signals that can be directly output as photoacoustic images for display, or can be signals that need to be processed in one or more steps before they can be output as photoacoustic images. The signals between the beam synthesis and the output as photoacoustic images are all applicable to the technical solutions related to photoacoustic image signals in various embodiments of the present application.

[0065] Step 204, detecting the moving speed of the photoacoustic composite probe;

[0066] 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 20 on the tissue to be tested, or the moving speed of the photoacoustic composite probe 20 in space.

[0067] It should be emphasized that the order of execution of the various steps in the various embodiments of this application is not limited. Unless otherwise specified, the steps may be executed in the order shown in the figures or in any other feasible order. In this embodiment, the detection of the movement speed of the photoacoustic composite probe 20 may be performed before step 201, after step 201 and before step 202, or after step 202 and before step 203, etc., in any feasible order.

[0068] Step 205: 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 a second photoacoustic imaging mode;

[0069] When the processor 70 detects that the movement speed of the photoacoustic composite probe 20 is less than a first preset threshold, it controls the switching from the first photoacoustic imaging mode to the second photoacoustic imaging mode. Using the movement speed of the photoacoustic composite probe 20 as the switching condition between the two photoacoustic imaging modes allows the optimal photoacoustic imaging mode to be matched to different probe movement speeds, thereby meeting the user's different photoacoustic imaging requirements when moving the photoacoustic composite probe 20 at different speeds. The first preset threshold here can be factory-set or user-set.

[0070] Step 206 , in the second photoacoustic imaging mode, controlling the photoacoustic composite probe to emit laser light at least twice toward the tissue to be measured;

[0071] In the second photoacoustic imaging mode, the processor 70 controls the photoacoustic composite probe 20 to emit laser light at least twice toward the tissue to be measured. The at least two lasers here refer to the process in which the laser 90 repeatedly emits laser light at least twice and stops emitting laser light under the control of the timing controller.

[0072] Step 207: Control the photoacoustic composite probe to respectively receive at least two ultrasonic waves generated by the tissue to be tested under the action of the at least two laser beams, so as to obtain at least two photoacoustic electrical signals, wherein the ultrasonic wave generated by the tissue to be tested under the action of one laser beam is considered as one ultrasonic wave, and the photoacoustic electrical signal obtained by receiving one ultrasonic wave is considered as one photoacoustic electrical signal;

[0073] The processor 70 controls the photoacoustic hybrid probe 20 to receive at least two ultrasonic waves generated by the tissue under test under the at least two laser beams, respectively, to obtain at least two photoacoustic electrical signals. The photoacoustic hybrid probe 20 emits a laser beam once toward the tissue under test, generating an ultrasonic wave within the tissue under test. The photoacoustic hybrid probe 20 then receives and processes the ultrasonic wave generated within the tissue under test to obtain a photoacoustic electrical signal. This process is repeated at least twice, resulting in the photoacoustic hybrid probe 20 obtaining at least two photoacoustic electrical signals.

[0074] Step 208: Process the at least two photoacoustic electrical signals to obtain a frame of photoacoustic image.

[0075] Processing the at least two photoacoustic electrical signals to obtain a frame of photoacoustic image can be performed by processing the at least two photoacoustic electrical signals through an analog-to-digital conversion module, a beamforming module, and a processor to obtain a frame of photoacoustic image. The process is not limited to the analog-to-digital conversion module, the beamforming module, and the processor. Other processing modules may be included in the process of processing the photoacoustic electrical signals to obtain a frame of photoacoustic image, and this embodiment does not impose any limitation thereto.

[0076] In the first photoacoustic imaging mode, the photoacoustic composite probe 20 emits a laser beam once toward the tissue to be tested to form a photoacoustic image frame. The imaging frame rate is fast, but the image quality is not high. The second photoacoustic imaging mode emits at least two laser beams to form a photoacoustic image frame. Due to the large number of laser beams, the large number of received photoacoustic electrical signals can obtain a higher-quality photoacoustic image. However, at the same time, the imaging frame rate will decrease accordingly, and the photoacoustic image will be updated slowly. Under normal circumstances, the frame rate and image quality of photoacoustic imaging performed in the first photoacoustic imaging mode can meet the requirements of general photoacoustic imaging. However, when the user slowly moves the photoacoustic composite probe 20 or keeps the photoacoustic composite probe 20 stationary on the tissue to be tested, the user often needs to carefully observe the photoacoustic image of the area of ​​the tissue to be tested. At this time, the photoacoustic image quality in the first mode will not meet the user's needs. This embodiment detects the movement speed of the photoacoustic composite probe 20 and switches from the first imaging mode to the second imaging mode when the movement speed of the photoacoustic composite probe 20 is less than a first preset threshold. In this case, the user moves the photoacoustic composite probe 20 slowly or keeps it stationary, often needing to carefully observe the photoacoustic image of the area, requiring high quality of the photoacoustic image. Furthermore, since the photoacoustic composite probe 20 moves slowly or does not move at all, the photoacoustic image does not change much, and the user does not require a high frame rate for the photoacoustic imaging. Therefore, in the second imaging mode, a single photoacoustic image frame is generated by emitting laser light at least twice at the tissue under test, thereby forgoing a high imaging frame rate while maintaining photoacoustic image quality, meeting the user's needs when slowly moving the photoacoustic composite probe 20 or keeping it stationary. This embodiment controls the switching between the first and second photoacoustic imaging modes by detecting the movement speed of the photoacoustic composite probe 20, thereby meeting the different needs of the user when moving the photoacoustic composite probe 20 in different scenarios.

[0077] In one embodiment, in the second photoacoustic imaging mode, processing at least two photoacoustic signals to obtain a frame of photoacoustic image can be performed by averaging the photoacoustic digitized signals, which can specifically 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 beamforming on the averaged photoacoustic digitized signal to obtain a target photoacoustic image signal; and processing the target photoacoustic image signal to obtain a frame of photoacoustic image.

[0078] The photoacoustic composite probe 20 emits a laser beam at least twice toward the tissue to be tested. The tissue to be tested generates at least two ultrasonic waves under the action of the laser beam. After receiving the at least two ultrasonic waves, the photoacoustic composite probe 20 processes the waves to obtain at least two photoacoustic electrical signals. Furthermore, an analog-to-digital conversion module converts the at least two photoacoustic electrical signals into at least two ultrasonic digital signals. Alternatively, a photoacoustic electrical signal is generated from a single laser beam, and the signal is converted into an ultrasonic digital signal, with the at least two photoacoustic electrical signals each being converted into at least two ultrasonic digital signals. Alternatively, a photoacoustic electrical signal is generated from a single laser beam, and after obtaining at least two photoacoustic electrical signals, the at least two photoacoustic electrical signals are converted together into at least two ultrasonic digital signals. The at least two photoacoustic digitized signals are averaged to obtain an averaged photoacoustic digitized signal. Averaging the at least two photoacoustic digitized signals can overcome random noise in individual photoacoustic digitized signals, resulting in a higher quality averaged photoacoustic digitized signal than the individual photoacoustic digitized signals. Furthermore, beam synthesis is performed on the average photoacoustic digitized signal to obtain a target photoacoustic image signal, and the target photoacoustic image signal is processed to obtain a frame of photoacoustic image. Since the quality of the average photoacoustic digitized signal is high at this time, the signal-to-noise ratio of the obtained photoacoustic image is higher than the signal-to-noise ratio of the photoacoustic image formed by a single photoacoustic digitized signal, which can meet the user's requirements for photoacoustic image quality when the photoacoustic composite probe 20 is slowly moved or kept stationary.

[0079] It should be noted that averaging the at least two photoacoustic digitized signals can be performed by averaging the signals at any processing stage between analog-to-digital conversion and beamforming. Subsequently, beamforming can be performed directly on the resulting average photoacoustic digitized signal, or the resulting average photoacoustic digitized signal can be subjected to other processing steps before beamforming. Averaging the at least two photoacoustic digitized signals to obtain an average photoacoustic digitized signal is used to convert the at least two signals into a single signal, and subsequently, a photoacoustic image frame is obtained. Although the imaging frame rate at this point is lower than that obtained by obtaining a photoacoustic image frame from a single photoacoustic digitized signal, the quality of the photoacoustic image is improved. This meets the user's need for detailed observation of the photoacoustic image and a low requirement for the photoacoustic imaging frame rate in scenarios where the user is moving the photoacoustic composite probe 20 slowly or not at all.

[0080] In one embodiment, in the second photoacoustic imaging mode, processing two photoacoustic signals to obtain a frame of photoacoustic image can be performed by averaging the photoacoustic image signals, which can specifically include: performing analog-to-digital conversion on the at least two photoacoustic electrical signals to obtain at least two photoacoustic digitized signals; performing beamforming 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; and processing the averaged photoacoustic image signal to obtain a frame of photoacoustic image.

[0081] The photoacoustic hybrid probe 20 emits a laser beam at least twice toward the tissue to be measured. The laser beam causes the tissue to generate at least two ultrasonic waves. After receiving the at least two ultrasonic waves, the photoacoustic hybrid probe 20 processes the signals to obtain at least two photoacoustic electrical signals. These at least two photoacoustic electrical signals are then analog-to-digital converted to obtain at least two photoacoustic digitized signals. These at least two photoacoustic digitized signals are then beamformed to obtain at least two photoacoustic image signals. Similar to the above embodiment, the beamformation process can be performed once for each photoacoustic digitized signal generated to obtain a photoacoustic image signal, with the at least two photoacoustic digitized signals being beamformed separately to obtain at least two photoacoustic image signals. Alternatively, after the at least two photoacoustic digitized signals are generated, the at least two photoacoustic digitized signals are converted together into at least two photoacoustic image signals. The at least two photoacoustic image signals are then averaged to obtain an averaged photoacoustic image signal. Averaging the at least two photoacoustic image signals can mitigate random noise in individual photoacoustic image signals, resulting in a higher quality averaged photoacoustic image signal than the individual photoacoustic image signals. Furthermore, the average photoacoustic image signal is processed to obtain a frame of photoacoustic image. Since the quality of the average photoacoustic image signal is higher at this time, the signal-to-noise ratio of the obtained photoacoustic image is higher than the signal-to-noise ratio of the photoacoustic image formed by a single photoacoustic image signal, which can meet the user's requirements for photoacoustic image quality when the photoacoustic composite probe 20 is slowly moved or kept stationary.

[0082] It should be noted that averaging the at least two photoacoustic image signals can be performed by averaging the signals from any processing stage between beamforming and outputting the photoacoustic image. The obtained averaged photoacoustic image signal can then be directly processed to obtain a photoacoustic image, or the obtained averaged photoacoustic image signal can be processed further to obtain a photoacoustic image frame. Averaging the at least two photoacoustic image signals to obtain an averaged photoacoustic image signal converts the at least two signals into one signal, and subsequently obtains a photoacoustic image frame. Although the imaging frame rate is lower than that obtained by obtaining a photoacoustic image frame from a single photoacoustic image signal, the quality of the photoacoustic image is improved. This meets the user's need for detailed observation of the photoacoustic image and a low requirement for the photoacoustic imaging frame rate in scenarios where the user is moving the photoacoustic composite probe 20 slowly or not at all.

[0083] In the second photoacoustic imaging mode, at least two photoacoustic electrical signals are processed to obtain a photoacoustic image frame. By averaging the at least two photoacoustic digitized signals or averaging the at least two photoacoustic image signals, the laser can be emitted multiple times to generate a photoacoustic image frame, thereby improving the quality of the photoacoustic image. Averaging the at least two photoacoustic digitized signals and then performing beamforming on the averaged photoacoustic digitized signal requires only one beamforming operation to obtain the target photoacoustic image signal, thereby obtaining a photoacoustic image frame. Averaging the at least two photoacoustic image signals requires performing beamforming on the at least two photoacoustic digitized signals at least twice to obtain at least two photoacoustic image signals, and then averaging the at least two photoacoustic image signals to obtain a photoacoustic image frame. In comparison, averaging the photoacoustic digitized signals requires fewer beamforming operations than averaging the photoacoustic image signals, resulting in a smaller total amount of operations and a faster processing time. This can improve the speed of photoacoustic imaging while ensuring the quality of the photoacoustic image.

[0084] Regarding step 204 , the moving speed of the photoacoustic composite probe is detected, specifically by using a sensor or ultrasonic image detection.

[0085] 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, or a distance sensor. For example, the moving speed of the photoacoustic composite probe 20 can be directly detected by a speed sensor provided on the photoacoustic composite probe 20; the moving speed of the photoacoustic composite probe 20 can also be indirectly detected by an acceleration sensor provided on the photoacoustic composite probe 20; the moving speed of the photoacoustic composite probe 20 can also be indirectly detected by a distance sensor by detecting the change in the distance between the photoacoustic composite probe 20 and a specific reference object. This embodiment does not limit the specific type of sensor; any sensor that can detect the moving speed of the photoacoustic composite probe 20 is within the scope of protection of this embodiment.

[0086] The moving speed of the photoacoustic composite probe 20 is detected by a sensor. The moving speed can be the moving speed of the probe on the tissue to be tested or the moving speed of the probe in space. Sometimes, when the user moves the photoacoustic composite probe 20 over a long distance between two areas of the target tissue, the user habitually lifts the probe away from the surface of the tissue to be tested and moves the probe 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.

[0087] Ultrasound imaging can also be performed simultaneously with photoacoustic imaging, and the movement speed of the photoacoustic composite probe 20 can be determined from the ultrasound images. In one embodiment, the photoacoustic composite probe acquires multiple consecutive ultrasound frames of the tissue under test; the movement speed of the photoacoustic composite probe over the tissue under test is detected from these consecutive ultrasound frames as the movement speed of the photoacoustic composite probe. For example, image changes between consecutive ultrasound frames can be detected, and the image changes per unit time can be used to reflect the movement speed of the photoacoustic composite probe 20.

[0088] In one embodiment, detecting the movement speed of the photoacoustic composite probe on the tissue to be measured through the continuous multi-frame ultrasound images includes: identifying a target area in the continuous multi-frame ultrasound images; and determining the movement speed of the photoacoustic composite probe on the tissue to be measured by the position change of the target area in the continuous multi-frame ultrasound images. It is understandable that when the photoacoustic composite probe 20 moves, the tissue in the ultrasound image formed by the photoacoustic composite probe 20 will also move accordingly, so the target area in the ultrasound image can be identified, and the target area is identified in the continuous multi-frame ultrasound images. The movement 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.

[0089] In another embodiment, detecting the movement speed of the photoacoustic composite probe over the tissue to be tested using the consecutive multiple frames of ultrasound images includes: identifying whether the consecutive multiple frames of ultrasound images contain a target region; determining the number of consecutive ultrasound images in the consecutive multiple frames of ultrasound images that contain the target region; and determining the movement speed of the photoacoustic composite probe over the tissue to be tested based on the number of frames. It is understood that when the photoacoustic composite probe 20 moves over the tissue to be tested, a specific target region in the multiple frames of ultrasound images acquired during the movement will appear from one edge of one ultrasound frame, gradually move toward the other edge in subsequent multiple frames of ultrasound images, and finally disappear from the other edge in the subsequent ultrasound frame. Since the faster the photoacoustic composite probe 20 moves, the faster the target region appears and disappears, the fewer frames of ultrasound images that contain the target region will be included. Conversely, the slower the photoacoustic composite probe 20 moves, the slower the target region appears and disappears, and the more frames of ultrasound images that contain the target region will be included. Therefore, by identifying whether the target area is included in multiple consecutive frames of ultrasound images, the number of frames of the consecutive ultrasound images containing the target area can be determined, and the moving speed of the photoacoustic composite probe 20 on the tissue to be measured can be determined based on the number of frames.

[0090] In one embodiment, identifying whether the target region is contained in the plurality of consecutive ultrasound image frames and determining the number of consecutive ultrasound image frames containing the target region in the plurality of consecutive ultrasound image frames includes: identifying whether the target region is contained in the plurality of consecutive ultrasound image frames frame by frame; starting counting the number of image frames when a frame is identified as containing the target region, and accumulating the number of image frames by one frame each time a frame is identified as containing the target region, until a frame is identified as not containing the target region, at which point counting of the image frames is stopped, and determining the number of image frames at the time of stopping. The counting of ultrasound images can be accomplished using a counter. By identifying whether the target region is contained in the plurality of consecutive ultrasound image frames frame by frame, counting is started when the target region is identified as containing the target region, and stopped when the target region first disappears, and the number of frames counted at the time of stopping is determined. The movement speed of the photoacoustic composite probe 20 is determined based on the number of frames. It is understood that the larger the number of frames, the slower the photoacoustic composite probe 20 moves, and the smaller the number of frames, the faster the photoacoustic composite probe 20 moves.

[0091] When determining the moving speed of the photoacoustic composite probe 20 by the number of frames of continuous ultrasound images containing the target area, the speed of the photoacoustic composite probe 20 can be directly represented by the number of frames of the ultrasound image, or the moving speed of the target area on the ultrasound image can be calculated by the frame rate of the ultrasound image, the size of the ultrasound image and the number of frames as the movement speed of the photoacoustic composite probe 20.

[0092] The target area may include, but is not limited to, at least one of the following: an area containing a specific anatomical structure, an area whose brightness meets preset conditions, and an area whose pixel gradient meets preset conditions. The specific anatomical structure may be determined based on the type of tissue being imaged for this photoacoustic imaging. The preset brightness conditions and pixel gradient conditions may be factory-set or user-defined. This embodiment does not restrict the type of target area, as long as the target area is easily identifiable on the ultrasound image.

[0093] Among them, the identification of target areas in continuous multi-frame ultrasound images can be performed through functions such as image similarity, or through a machine learning model. In this embodiment, there is no restriction on the method of identifying target areas in continuous multi-frame ultrasound images.

[0094] like Figure 3 As shown, the present application provides a photoacoustic imaging method, which can determine the number of lasers emitted to form a frame of photoacoustic image based on the moving speed of the photoacoustic composite probe. The method may include the following steps:

[0095] Step 301, detecting the moving speed of the photoacoustic composite probe;

[0096] During the photoacoustic imaging process, the user holds the photoacoustic composite probe 20 and places it on the surface of the tissue to be measured. The photoacoustic composite probe 20 emits laser to the tissue to be measured and receives ultrasonic waves generated by the tissue to be measured under the action of the laser. The photoacoustic composite probe 20 converts the received ultrasonic waves into photoacoustic electrical signals, which are further used for subsequent processing to obtain photoacoustic images. The user observes the photoacoustic images to evaluate the health status of the tissue to be measured.

[0097] Depending on clinical needs, the user often slowly moves the photoacoustic composite probe 20 or keeps it stationary over an area requiring particular attention to carefully observe the photoacoustic image of that area. For areas of non-key interest, the user often quickly moves the photoacoustic composite probe 20 to sweep across them. Alternatively, between two areas of key interest, the user quickly moves the photoacoustic composite probe 20 to switch between them. During this process, when the user slowly moves the photoacoustic composite probe 20 or keeps it stationary, the doctor needs to carefully observe the photoacoustic image of that area, and in this case, the user has higher requirements for the image quality of the photoacoustic image. However, when the user quickly moves the photoacoustic composite probe 20, the user does not need to carefully observe the photoacoustic image of the area being moved through, but often requires that the corresponding photoacoustic image be observed in a timely manner at each position during the rapid movement. In this case, the user does not have high requirements for the image quality of the photoacoustic image, but requires a photoacoustic imaging frame rate that is large enough to match the movement 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 according to the moving speed of the photoacoustic composite probe 20 .

[0098] Step 302, determining the number of laser shots N based on the moving speed;

[0099] The processor 70 determines the number of laser shots N based on the movement speed of the photoacoustic composite probe 20 determined in step 301. It will be appreciated that the number of laser shots N can adaptively vary with the movement speed of the photoacoustic composite probe 20, so that the number of laser shots can adapt to the user's photoacoustic image requirements at different movement speeds of the photoacoustic composite probe 20. It will be appreciated that the number of laser shots N can be any integer greater than or equal to 1.

[0100] In one embodiment, the number of laser shots N can be determined based on the movement speed and a preset correspondence, wherein the preset correspondence is a correspondence between the movement speed of the photoacoustic composite probe 20 and the number of laser shots N, wherein the correspondence is a negative correlation. The preset correspondence can be a functional relationship between the movement speed of the photoacoustic composite probe 20 and the number of laser shots N. When the movement speed of the photoacoustic composite probe 20 is known, the corresponding number of laser shots N can be calculated using this functional relationship. The preset correspondence can also be another correspondence between the movement speed of the photoacoustic composite probe 20 and the number of laser shots N. For example, when the movement speed of the photoacoustic composite probe 20 is known, the corresponding number of laser shots N can be determined by looking up a table. In this embodiment, the correspondence can be a negative correlation, i.e., the greater the movement speed of the photoacoustic composite probe 20, the smaller the corresponding number of laser shots N; and the slower the movement speed of the photoacoustic composite probe 20, the larger the corresponding number of laser shots N. This accommodates the user's demand for a higher imaging frame rate when quickly moving the photoacoustic composite probe 20, and the user's demand for higher image quality when slowly moving the photoacoustic composite probe 20 or keeping it stationary. The specific negative correlation between the movement speed of the photoacoustic composite probe 20 and the number of laser shots N can be factory preset or user-defined based on clinical needs. Furthermore, the determined number of laser shots can be displayed on the display 80, as can the detected movement speed of the photoacoustic composite probe 20.

[0101] In one embodiment, the preset correspondence can be a correspondence between the moving speed gear of the photoacoustic composite probe 20 and the number of laser emissions N. For example, the moving speed of the photoacoustic composite probe 20 can be divided into three speed gears: fast, medium, and slow, wherein each speed gear represents a range of probe movement speeds, and each gear corresponds to a number of laser emissions N. For example, when the current moving speed of the photoacoustic composite probe 20 falls into the slow gear, the number of laser emissions N 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 of laser emissions N is determined to be 5 according to the preset correspondence; and when the current moving speed of the photoacoustic composite probe 20 falls into the fast gear, the number of laser emissions N is determined to be 1 according to the preset correspondence. Furthermore, the speed gear corresponding to the moving speed of the photoacoustic composite probe 20 can be displayed on the display 80, and the corresponding number of laser emissions can also be displayed on the display 80.

[0102] Step 303, controlling the photoacoustic composite probe to emit N lasers toward the tissue to be tested;

[0103] The processor 70 controls the photoacoustic composite probe 20 to emit laser light N times toward the tissue to be measured. The process from the laser 90 emitting laser light to stopping emitting laser light under one emission instruction of the timing controller is that the photoacoustic composite probe 20 emits laser light toward the tissue to be measured once. This process is repeated N times, and the photoacoustic composite probe 20 completes N laser emissions toward the tissue to be measured. These N laser emissions will be used to subsequently obtain a frame of photoacoustic image.

[0104] Step 304: Control the photoacoustic composite probe to respectively receive N ultrasonic waves generated by the tissue to be tested under the N laser beams to obtain N photoacoustic electrical signals, wherein each ultrasonic wave generated by the tissue to be tested under the laser beams emitted once is considered as one ultrasonic wave, and each photoacoustic electrical signal obtained by receiving one ultrasonic wave is considered as one photoacoustic electrical signal.

[0105] The processor 70 controls the photoacoustic composite probe 20 to receive N ultrasonic waves generated by the tissue under test under N laser beams, thereby obtaining N photoacoustic electrical signals. Each ultrasonic wave generated by the tissue under test under the action of a single laser beam is considered a single ultrasonic wave. This process involves the photoacoustic composite probe 20 emitting a single laser beam toward the tissue under test, receiving a single ultrasonic wave generated by the tissue under test under the action of the laser beam, and converting the single ultrasonic wave into a photoacoustic electrical signal. This process is repeated N times to obtain N photoacoustic electrical signals.

[0106] Step 305 : Process the N photoacoustic electrical signals to obtain a frame of photoacoustic image.

[0107] Processing the N photoacoustic electrical signals to obtain a frame of photoacoustic image may be 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 image. The process is not limited to the analog-to-digital conversion module, the beamforming module, and the processor. Other processing modules may be included in the process of processing the photoacoustic electrical signals to obtain a frame of photoacoustic image, and this embodiment does not impose any limitation thereto.

[0108] It is understandable that the more photoacoustic electrical signals are processed to obtain a frame of photoacoustic image, the higher the image quality of the frame of photoacoustic image. However, since the time it takes for a laser to emit a laser is fixed, the more laser emissions are taken, the lower the imaging frame rate is. Conversely, if fewer photoacoustic electrical signals are processed to obtain a frame of photoacoustic image, for example, one photoacoustic electrical signal is processed to obtain a frame of photoacoustic image, the imaging frame rate is higher because a single laser emission can produce a frame of photoacoustic image. However, since a single laser emission produces a frame of photoacoustic image, the frame of photoacoustic image is greatly affected by the laser emission and ultrasound reception, and some random noise cannot be removed, making the quality of the frame of photoacoustic image lower than that of a frame of photoacoustic image produced by multiple laser emissions. Since the characteristics of a frame of photoacoustic image produced by different numbers of laser emissions are different, they can be matched according to the needs of the clinician. In this embodiment, the movement speed of the photoacoustic composite probe 20 is negatively correlated with the number of laser emissions N. When the doctor moves the photoacoustic composite probe 20 quickly, they need to pay attention to the rapidly changing photoacoustic image and have low requirements for image quality. Therefore, when the photoacoustic composite probe 20 moves quickly, the number of laser shots N is determined to be small, for example, one or two laser shots form one photoacoustic image frame. This can meet the doctor's imaging frame rate requirements when the photoacoustic composite probe 20 is moved quickly. When the doctor moves the photoacoustic composite probe 20 slowly or keeps it stationary, the doctor needs to focus on the photoacoustic image of the area of ​​the tissue to be tested. In this case, the user has high requirements for photoacoustic image quality. Since the photoacoustic composite probe 20 moves slowly or remains stationary, the imaging area of ​​the photoacoustic composite probe 20 changes slowly or inconveniently. In this case, the update speed of the photoacoustic image is not required to be high, that is, a lower imaging frame rate can be used without affecting the user's observation. Therefore, when the photoacoustic composite probe 20 moves slowly, the number of laser shots N is determined to be large, for example, 10 laser shots form one photoacoustic image frame. This can meet the doctor's requirements for photoacoustic image quality.

[0109] In one embodiment, the N photoacoustic electrical signals can be analog-to-digital converted to obtain N photoacoustic digitized signals; the N photoacoustic digitized signals can be averaged to obtain an average photoacoustic digitized signal; the average photoacoustic digitized signal can be beamformed to obtain a target photoacoustic image signal; and the target photoacoustic image signal can be processed to obtain a frame of photoacoustic image.

[0110] The photoacoustic composite probe 20 emits N laser beams toward the tissue to be tested. Under the action of the laser beam, the tissue to be tested generates N ultrasonic waves. After receiving the N ultrasonic waves, the photoacoustic composite probe 20 processes and obtains N photoacoustic electrical signals. Furthermore, the N photoacoustic electrical signals are converted into N ultrasonic digitized signals by an analog-to-digital conversion module. For example, one photoacoustic electrical signal is obtained for each laser beam, and this one photoacoustic electrical signal is converted into one ultrasonic digitized signal. These N photoacoustic electrical signals can be converted into N ultrasonic digitized signals individually. Alternatively, one photoacoustic electrical signal is obtained for each laser beam, and after obtaining N photoacoustic electrical signals, these N photoacoustic electrical signals are converted into N ultrasonic digitized signals. These N photoacoustic digitized signals are averaged to obtain an average photoacoustic digitized signal. Furthermore, the average photoacoustic digitized signal is beamformed to obtain a target photoacoustic image signal. The target photoacoustic image signal is processed to obtain a single photoacoustic image frame. It can be understood that when the value of the number of laser emissions N is larger, more photoacoustic digitized signals will be averaged. The more photoacoustic digitized signals are averaged, the smaller the impact of random noise in a single photoacoustic digitized signal on the photoacoustic image, and the higher the quality of the photoacoustic image, but the corresponding imaging frame rate of the photoacoustic image will also be reduced accordingly.

[0111] When the photoacoustic composite probe 20 is moving at a slow speed, the number of laser irradiations N is large, for example, ten. The photoacoustic composite probe 20 irradiates the tissue under test with ten laser irradiations, generating ten photoacoustic electrical signals. These ten photoacoustic electrical signals undergo analog-to-digital conversion to generate ten photoacoustic digitized signals. Averaging the ten photoacoustic digitized signals overcomes random noise at random locations within individual photoacoustic digitized signals, resulting in a higher quality averaged photoacoustic digitized signal than a single photoacoustic digitized signal. Furthermore, beamforming is performed on the averaged photoacoustic digitized signal to generate a target photoacoustic image signal, which is then processed to generate a frame of photoacoustic image. Due to the higher quality of the averaged photoacoustic digitized signal, the resulting photoacoustic image has a higher signal-to-noise ratio (SNR) than a photoacoustic image generated from a single photoacoustic digitized signal. Furthermore, because far-field noise in the photoacoustic image is reduced after averaging multiple signals, the far-field image is clearer, resulting in a higher imaging depth. This can meet the user's requirements for photoacoustic image quality when the photoacoustic composite probe 20 is moving slowly or when the photoacoustic composite probe 20 is stationary.

[0112] When the photoacoustic composite probe 20 is moving at a faster speed, the number of laser shots N is smaller, for example, once. The photoacoustic composite probe 20 emits a laser shot at the tissue to be tested, generating a photoacoustic electrical signal. This photoacoustic electrical signal undergoes analog-to-digital conversion to generate a photoacoustic digitized signal. Averaging the photoacoustic digitized signal can be considered to generate the photoacoustic digitized signal itself. Furthermore, beamforming is performed on the photoacoustic digitized signal to generate a target photoacoustic image signal, which is then processed to generate a photoacoustic image frame. In this case, a single laser shot can generate a single photoacoustic image frame, resulting in a higher imaging frame rate. This can meet the user's requirement for a timely display of the photoacoustic image of the area covered by the probe when the photoacoustic composite probe 20 is moved rapidly. However, since one laser emission obtains one frame of photoacoustic image, it is greatly affected by the quality of the photoacoustic digitized signal obtained by this one laser emission. The random noise at random positions in this one photoacoustic digitized signal cannot be reduced by averaging multiple photoacoustic digitized signals. Therefore, the quality of the photoacoustic image at this time is lower than the quality of the photoacoustic image when the number of laser emissions N is large. However, at this time, the user does not need to observe each frame of the photoacoustic image in detail, so the quality of the photoacoustic image at this time can meet the user's needs.

[0113] It should be noted that averaging the N photoacoustic digitized signals may be averaging the signals at any processing stage from analog-to-digital conversion to beamforming. Subsequently, beamforming may be directly performed on the obtained averaged photoacoustic digitized signal, or the obtained averaged photoacoustic digitized signal may be subjected to other processing steps before beamforming. The signal after beamforming is the target photoacoustic image signal, and processing the target photoacoustic image signal may obtain a frame of photoacoustic image.

[0114] In one embodiment, the N photoacoustic electrical signals can be analog-to-digital converted to obtain N photoacoustic digitized signals; beamforming can be performed on the N photoacoustic digitized signals to obtain N photoacoustic image signals; the N photoacoustic image signals can be averaged to obtain an average photoacoustic image signal; and the average photoacoustic image signal can be processed to obtain a frame of photoacoustic image.

[0115] The photoacoustic composite probe 20 emits N laser beams toward the tissue to be tested. The tissue to be tested generates N ultrasonic waves under the action of the laser beams. After receiving the N ultrasonic waves, the photoacoustic composite probe 20 processes and obtains N photoacoustic electrical signals. These N photoacoustic electrical signals are converted from analog to digital to obtain N photoacoustic digitized signals. These N photoacoustic digitized signals are then beamformed to obtain N photoacoustic image signals. Similar to the above embodiment, the beamformation process can be performed once for each photoacoustic digitized signal generated to obtain a photoacoustic image signal, with the N photoacoustic digitized signals being beamformed separately to obtain N photoacoustic image signals. Alternatively, after the N photoacoustic digitized signals are generated, the N photoacoustic digitized signals are converted into N photoacoustic image signals. These N photoacoustic image signals are averaged to obtain an average photoacoustic image signal. The average photoacoustic image signal is then processed to obtain a single photoacoustic image frame. It can be understood that when the value of the number of laser emissions N is larger, more photoacoustic image signals will be averaged. The more photoacoustic image signals are averaged, the smaller the impact of random noise in a single photoacoustic image signal on the photoacoustic image, and the higher the quality of the photoacoustic image, but the corresponding imaging frame rate of the photoacoustic image will also be reduced accordingly.

[0116] When the photoacoustic composite probe 20 moves slowly, the number of laser emissions N is large, for example, ten. The photoacoustic composite probe 20 emits the laser ten times toward the tissue to be tested, generating ten photoacoustic electrical signals. These ten photoacoustic electrical signals undergo analog-to-digital conversion to generate ten photoacoustic digitized signals. Beamforming the ten digitized photoacoustic signals generates ten photoacoustic image signals. Averaging the ten photoacoustic image signals overcomes random noise at random locations within individual photoacoustic image signals, resulting in a higher quality averaged photoacoustic image signal than a single photoacoustic image signal. Furthermore, 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 higher than the signal-to-noise ratio of the photoacoustic image converted from a single photoacoustic digitized signal. Moreover, since the far-field noise in the photoacoustic image is weakened after averaging multiple signals, the far-field image is clearer. In comparison, the imaging depth of the image can be improved, which can meet the user's requirements for photoacoustic image quality when slowly moving the photoacoustic composite probe 20 or keeping the photoacoustic composite probe 20 stationary.

[0117] When the photoacoustic composite probe 20 is moving at a faster speed, the number of laser shots N is smaller, for example, two. The photoacoustic composite probe 20 then fires the laser twice at the tissue under test, generating two photoacoustic electrical signals. These two photoacoustic electrical signals undergo analog-to-digital conversion to generate two photoacoustic digitized signals. These two photoacoustic digitized signals are beamformed to generate two photoacoustic image signals. The two photoacoustic image signals are averaged to generate an average photoacoustic image signal, which is then processed to generate a single photoacoustic image frame. In this case, two laser shots generate a single photoacoustic image frame, resulting in a higher imaging frame rate. This can meet the user's requirement for a timely display of the photoacoustic image of the area covered by the probe when the photoacoustic composite probe 20 is being moved rapidly. However, since one frame of photoacoustic image is obtained by two laser emissions, the quality of the photoacoustic image signals obtained by the two laser emissions is greatly affected. The random noise at random positions in the two photoacoustic image signals cannot be reduced by averaging multiple photoacoustic image signals. Therefore, the quality of the photoacoustic image at this time is lower than the quality of the photoacoustic image when the number of laser emissions N is large. However, the user does not need to observe each frame of the photoacoustic image in detail at this time, so the quality of the photoacoustic image at this time can meet the user's needs.

[0118] It should be noted that averaging the N photoacoustic image signals may be averaging the signals at any processing stage from beamforming to outputting the photoacoustic image. The obtained averaged photoacoustic image signal may be directly processed to obtain a photoacoustic image, or the obtained averaged photoacoustic image signal may be subjected to other processing before being processed to obtain a frame of photoacoustic image.

[0119] Depending on the frame rate and image quality requirements of clinical photoacoustic imaging, the number of laser shots 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 rapidly, the number of laser shots N can be 1; when the photoacoustic composite probe 20 remains stationary, the number of laser shots N can be 15; and when the photoacoustic composite probe 20 moves at a moderate speed, the number of laser shots N can be 8. The specific value of the number of laser shots N can be determined based on the movement speed of the photoacoustic composite probe 20. The range of the number of laser shots N can be preset by the factory or set according to user needs.

[0120] In step 301 , the moving speed of the photoacoustic composite probe is detected by providing a sensor on the photoacoustic composite probe 20 or by detecting an ultrasonic image.

[0121] In one embodiment, a sensor may be provided on the photoacoustic composite probe 20 to detect the moving speed of the photoacoustic composite probe 20. The sensor provided on the photoacoustic composite probe 20 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, the present application does not limit the type of sensor.

[0122] In one embodiment, a photoacoustic composite probe is used to obtain continuous multiple-frame ultrasound images of the tissue to be measured; and the moving speed of the photoacoustic composite probe on the tissue to be measured is detected by using the continuous multiple-frame ultrasound images as the moving speed of the photoacoustic composite probe.

[0123] In one implementation, the movement speed of the photoacoustic composite probe on the tissue to be measured is detected by using multiple consecutive frames of ultrasound images. The target area in the multiple consecutive frames of ultrasound images can be identified; and the movement speed of the photoacoustic composite probe on the tissue to be measured is determined by the position change of the target area in the multiple consecutive frames of ultrasound images.

[0124] In another implementation, the moving speed of the photoacoustic composite probe on the tissue to be measured is detected by using continuous multiple-frame ultrasound images. This can be done by identifying whether the continuous multiple-frame ultrasound images contain a target area; determining the number of continuous ultrasound images in the continuous multiple-frame ultrasound images that contain the target area; and determining the moving speed of the photoacoustic composite probe on the tissue to be measured based on the number of frames.

[0125] Specifically, identifying whether a target area is included in a continuous multi-frame ultrasound image and determining the number of frames of the continuous multi-frame ultrasound image that include the target area can be achieved by identifying whether the target area is included in the continuous multi-frame ultrasound image frame by frame; counting the number of image frames starts when a frame of ultrasound image is identified as including the target area, and the number of image frames accumulates by one frame each time a frame of ultrasound image is continuously identified as including the target area, until counting the number of image frames stops when a frame of ultrasound image is identified as not including the target area, and determining the number of image frames at the time of stopping.

[0126] The target area may include 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 a preset condition.

[0127] The method for detecting the moving speed of the photoacoustic composite probe 20 can be referred to the above discussion and will not be repeated here.

[0128] like Figure 4 As shown, the present application provides a photoacoustic imaging method, which can determine whether to emit laser to perform photoacoustic imaging based on the moving speed of the photoacoustic composite probe. The method may include the following steps:

[0129] Step 401, detecting the moving speed of the photoacoustic composite probe;

[0130] The processor 70 detects the movement speed of the photoacoustic probe to determine whether to subsequently emit laser light to obtain a photoacoustic image. During photoacoustic imaging, the user holds the photoacoustic composite probe 20 and places it on a scanning area on the surface of the tissue to be tested. When the user needs to adjust the photoacoustic imaging area, the user holds the photoacoustic composite probe 20 and quickly moves it to the next scanning area of ​​the tissue to be tested. When the user moves the photoacoustic composite probe 20 to the next scanning area of ​​the tissue to be tested, the user maintains the photoacoustic composite probe 20 stationary or slowly moves it in the next scanning area of ​​the tissue to be tested to perform photoacoustic imaging. In the above process, the user is often only concerned with the photoacoustic image of the scanning area of ​​the tissue to be tested, and the process of rapidly moving the probe is often only for moving from one scanning area to another. Therefore, the user is not concerned with the photoacoustic image during movement, or has low requirements for the image quality of the photoacoustic image during movement. Therefore, whether to emit laser light to generate a photoacoustic image can be determined based on the movement speed of the probe.

[0131] The method for detecting the moving speed of the photoacoustic composite probe 20 can be referred to the above discussion and will not be repeated here.

[0132] Step 402: When the moving speed satisfies a first preset condition, controlling the photoacoustic composite probe to not emit laser light toward the tissue to be measured;

[0133] When the processor determines that the movement speed of the photoacoustic composite probe 20 meets a first preset condition, the processor controls the photoacoustic composite probe 20 to not emit laser light toward the tissue to be measured. This first preset condition can be set based on clinical needs. When the movement speed of the photoacoustic composite probe 20 meets this condition, laser light is not emitted toward the tissue to be measured, and the user does not need to perform photoacoustic imaging.

[0134] In one embodiment, the first preset condition is that the movement speed is greater than or equal to a second preset threshold. When the photoacoustic composite probe 20 moves too quickly, the user often moves the photoacoustic composite probe 20 from one scanning area of ​​the tissue to be measured to another. The user generally only focuses on the photoacoustic images of the two scanning areas and is not interested in the photoacoustic images of the areas passed through during the movement. The user often only needs to move the photoacoustic composite probe 20 from one scanning area to the other as quickly as possible. Therefore, the user's intention can be determined by the movement speed of the photoacoustic composite probe 20. The user's intention can be determined by setting a second preset threshold. When the speed at which the user moves the photoacoustic composite probe 20 is greater than or equal to the second preset threshold, it can be determined that the user is switching between two scanning areas, or the user may have accidentally shaken the photoacoustic composite probe 20. Therefore, the photoacoustic composite probe 20 can be controlled not to emit laser light toward the tissue to be measured, thereby reducing the amount of laser light incident on the tissue to be measured and ensuring the safety of the photoacoustic imaging process. Furthermore, since the user is not interested in the photoacoustic image at this time, not emitting laser light for photoacoustic imaging can reduce the device's computational workload and improve subsequent operating speed.

[0135] The second preset threshold here can be set based on the user's operating habits, and can be preset by the factory or set by the user.

[0136] Step 403: When the movement speed meets the second preset condition, the photoacoustic composite probe is controlled to emit a laser toward the tissue to be measured, and the photoacoustic composite probe is controlled to receive ultrasonic waves generated by the tissue to be measured under the action of the laser to obtain a photoacoustic electrical signal, and the photoacoustic electrical signal is processed to obtain a photoacoustic image.

[0137] When the processor determines that the movement speed of the photoacoustic composite probe 20 meets a second preset condition, it controls the photoacoustic composite probe 20 to emit a laser beam toward the tissue to be tested. Based on the photoacoustic electrical signal obtained from the ultrasound waves generated by the tissue to be tested under the action of the laser beam, the photoacoustic composite probe 20 is further processed to obtain a photoacoustic image. When the movement speed of the photoacoustic composite probe 20 meets the second preset condition, the photoacoustic composite probe 20 can be controlled to emit a laser beam toward the tissue to be tested once, or it can be controlled to emit a laser beam at least twice toward the tissue to be tested, thereby obtaining one or at least two photoacoustic electrical signals. Furthermore, one or more photoacoustic images can be generated based on the one or at least two photoacoustic electrical signals. The second preset condition can be set based on clinical needs. When the movement speed of the photoacoustic composite probe 20 meets this condition, it can be inferred that the user needs to obtain a photoacoustic image of the region of the tissue to be tested for observation. The photoacoustic composite probe 20 then emits a laser beam toward the tissue to be tested to obtain a photoacoustic image.

[0138] In one embodiment, the second preset condition is that the movement speed is less than the second preset threshold. When the photoacoustic composite probe 20 moves slowly or remains stationary, the user often needs to carefully observe the photoacoustic image of the area of ​​the tissue to be tested, necessitating the emission of laser light and photoacoustic imaging. The user's intention can be determined by setting a second threshold. When the speed at which the user moves the photoacoustic composite probe 20 is less than the second threshold, it is determined that the user needs to observe the photoacoustic image of the area where the photoacoustic composite probe 20 is located. Therefore, the photoacoustic composite probe 20 can be controlled to emit laser light toward the tissue to be tested to obtain a photoacoustic image. By setting the second preset threshold, when the user needs to observe the photoacoustic image, the laser light is emitted for photoacoustic imaging to obtain a photoacoustic image for the user to observe, thereby satisfying the user's needs. When the user does not need to observe the photoacoustic image, the laser light is not emitted and photoacoustic imaging is not performed, thus saving computational complexity and improving safety.

[0139] Furthermore, when the movement speed of the photoacoustic composite probe 20 satisfies a second preset condition, the number of laser shots N can be determined based on the movement speed; the photoacoustic composite probe is controlled to shoot N laser shots at the tissue to be tested; the photoacoustic composite probe is controlled to receive N ultrasonic waves generated by the tissue to be tested under the action of the N laser shots, respectively, to obtain N photoacoustic electrical signals, wherein the ultrasonic wave generated by the tissue to be tested under the action of one laser shot is one ultrasonic wave, and the photoacoustic electrical signal obtained by receiving one ultrasonic wave is one photoacoustic electrical signal; and the N photoacoustic electrical signals are processed to obtain one frame of photoacoustic image. When the movement speed satisfies the second preset condition, it can be inferred that the user needs to observe the photoacoustic image. However, in different situations, the user's requirements for the frame rate and image quality of the photoacoustic image are also different. Therefore, when the movement speed satisfies the second preset condition, the number of laser shots N required to produce one frame of photoacoustic image can be further determined based on the movement speed. When the speed of movement of the photoacoustic composite probe 20 indicates that the user requires high-quality photoacoustic images but does not require a high imaging frame rate, the number of laser shots N can be larger, so that more laser shots are fired to form a single photoacoustic image frame, thereby improving the quality of the photoacoustic image. When the speed of movement of the photoacoustic composite probe 20 indicates that the user requires a higher photoacoustic image update rate but does not require a high quality of the photoacoustic image, the number of laser shots N can be smaller, so that fewer laser shots are fired to form a single photoacoustic image frame, thereby improving the frame rate of the photoacoustic imaging.

[0140] In one embodiment, the number of laser shots N can be determined based on the movement speed and a preset correspondence, wherein the preset correspondence is a negative correlation between the movement speed of the photoacoustic composite probe and the number of laser shots N. That is, the greater the movement speed of the photoacoustic composite probe 20, the smaller the corresponding number of laser shots N; and the slower the movement speed of the photoacoustic composite probe 20, the larger the corresponding number of laser shots N. This allows for adapting to the user's demand for a higher imaging frame rate when quickly moving the photoacoustic composite probe 20, and the user's demand for higher image quality when slowly moving the photoacoustic composite probe 20 or keeping it stationary.

[0141] Unless otherwise specified, the associated technical features in the various embodiments described above can be applied in other embodiments. For the description of the associated technical features, please refer to the associated embodiments, and the repeated parts will not be repeated.

[0142] like Figure 1 As shown, the present application also provides a photoacoustic imaging system, which can be used to perform the photoacoustic imaging methods of the above embodiments. The photoacoustic imaging system includes: a laser, a photoacoustic composite probe, and a processor;

[0143] The laser is used to generate laser light and transmit the laser light to the target tissue through the optical transmission device;

[0144] The photoacoustic composite probe is used to receive the photoacoustic signal returned from the target tissue;

[0145] The processor is used to process the photoacoustic signal to obtain a photoacoustic image;

[0146] The processor may be configured to execute the method described in the above embodiment.

[0147] In addition, according to an embodiment of the present application, a storage medium is also provided, on which program instructions are stored. When the program instructions are executed by a computer or processor, the computer or processor is used to execute the corresponding steps of the photoacoustic imaging method of the embodiment of the present application. 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, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disc read-only memory (CD-ROM), a USB memory, or any combination of the above storage media.

[0148] It should be emphasized that controlling the photoacoustic composite probe 20 to not emit laser light toward the tissue to be measured, controlling the photoacoustic composite probe 20 to emit laser light toward the tissue to be measured, controlling the photoacoustic composite probe 20 to emit laser light toward the tissue to be measured at least twice, and controlling the photoacoustic composite probe 20 to emit laser light toward the tissue to be measured N times can all be described as controlling the laser to not emit laser light or to emit laser light a corresponding number of times. It is understood that if a laser emits laser light, the laser light emitted by the laser is incident on the tissue to be measured from the photoacoustic composite probe 20 via the optical transmission device, which can be considered as the photoacoustic composite probe 20 emitting laser light toward the tissue to be measured. Therefore, controlling the photoacoustic composite probe 20 to emit laser light toward the tissue to be measured, as described herein, also includes controlling the laser light to emit laser light and transmitting the laser light through the photoacoustic composite probe 20 toward the tissue to be measured. Similarly, if the laser does not emit laser light, the photoacoustic composite probe also does not emit laser light. Therefore, controlling the photoacoustic composite probe 20 to not emit laser light toward the tissue to be measured, as described herein, also includes controlling the laser light to not emit laser light, thereby preventing the photoacoustic composite probe 20 from emitting laser light toward the tissue to be measured.

[0149] It should be noted that the embodiments of the present application are not limited to photoacoustic imaging for humans, but can also be used for photoacoustic imaging for animals.

[0150] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely illustrative and are not intended to limit the scope of the present application. Various changes and modifications may be made therein by those skilled 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 the present application as required by the appended claims.

[0151] Those skilled in the art will appreciate 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. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0152] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units described is merely a logical function division. In actual implementation, other division methods may be used, such as combining or integrating multiple units or components into another device, or ignoring or not performing some features.

[0153] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0154] Similarly, it should be understood that in order to streamline the present application and aid in understanding one or more of the various inventive aspects, in the description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof. However, this approach of the present application should not be interpreted as reflecting the intention that the application claimed for protection requires more features than those explicitly recited in each claim. More precisely, as reflected in the corresponding claims, the inventive point is that the corresponding technical problem can be solved with fewer features than all the features of a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into the detailed description, with each claim itself serving as a separate embodiment of the present application.

[0155] It will be understood by those skilled in the art that, except where mutually exclusive, all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or units of any method or apparatus disclosed herein may be combined in any combination. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature providing the same, equivalent, or similar purpose.

[0156] Furthermore, those skilled in the art will appreciate that although some embodiments described herein include certain features included in other embodiments but not other features, combinations of features from different embodiments are intended to be within the scope of this application and to form different embodiments. For example, in the claims, any of the claimed embodiments may be used in any combination.

[0157] The various component embodiments of the present application can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art will appreciate that in practice, a microprocessor or digital signal processor (DSP) can be used to implement some or all of the functions of some modules in the article analysis device according to the embodiments of the present application. The present application can also be implemented as a mammography program (e.g., a computer program and a computer program product) for executing part or all of the methods described herein. Such a program for implementing the present application can be stored on a computer-readable medium, or can have the form of one or more signals. Such a signal can be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0158] It should be noted that the above embodiments illustrate rather than limit the present application, and that a person skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present application may be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In a unit claim listing several mammography machines, several of these mammography machines may be embodied by the same item of hardware. The use of the words first, second, and third, etc. does not indicate any order. These words may be interpreted as names.

[0159] The above description is merely a specific embodiment or illustration of a specific embodiment of the present application, and the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. The scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A photoacoustic imaging method, characterized in that: include: In the first photoacoustic imaging mode: Controlling the photoacoustic composite probe to emit a laser once toward the tissue to be tested; Controlling the photoacoustic composite probe to receive an ultrasonic wave generated by the tissue to be tested under the action of the laser once, so as to obtain a photoacoustic electrical signal; Processing the 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 at least twice toward the tissue to be tested; Controlling the photoacoustic composite probe to respectively receive at least two ultrasonic waves generated by the tissue to be tested under the action of the at least two laser beams to obtain at least two photoacoustic electrical signals, wherein the ultrasonic wave generated by the tissue to be tested under the action of one laser beam emission is one ultrasonic wave, and the photoacoustic electrical signal obtained by receiving one ultrasonic wave is one photoacoustic electrical signal; The at least two photoacoustic electrical signals are processed to obtain a frame of photoacoustic image.

2. The method according to 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 according to 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 by the photoacoustic composite probe; The moving speed of the photoacoustic composite probe on the tissue to be tested is detected by using the continuous multi-frame ultrasound 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 tested by using the continuous multi-frame ultrasound images includes: Identifying a target area in the continuous multi-frame ultrasound image; 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 image.

5. The method according to claim 3, wherein The detecting the moving speed of the photoacoustic composite probe on the tissue to be tested by using the continuous multi-frame ultrasound images includes: Identifying whether the continuous multiple frames of ultrasound images contain a target area; Determining the number of consecutive ultrasound image frames containing the target area in the consecutive multiple ultrasound image frames; The moving speed of the photoacoustic composite probe on the tissue to be measured is determined by the frame number.

6. The method according to claim 5, wherein Identifying whether the continuous multi-frame ultrasound images include a target area and determining the number of frames of the continuous multi-frame ultrasound images that include the target area includes: Identifying frame by frame whether the continuous multiple frames of ultrasound images contain a target area; The counting of the number of image frames starts when the target area is recognized in a frame of ultrasound image. Each time the target area is recognized in a frame of ultrasound image, the number of image frames accumulates by one frame until the counting of the number of image frames stops when the target area is recognized in a frame of ultrasound image. The number of image frames at the time of stopping is determined.

7. The method according to any one of claims 4 to 6, wherein: The target area includes 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 a preset condition.

8. The method according to any one of claims 1 to 6, wherein: In the second photoacoustic imaging mode, processing the at least two photoacoustic electrical signals to obtain a frame of photoacoustic image includes: 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 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.

9. The method according to claim 7, wherein: In the second photoacoustic imaging mode, processing the at least two photoacoustic electrical signals to obtain a frame of photoacoustic image includes: 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 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.

10. The method according to any one of claims 1 to 6, wherein: In the second photoacoustic imaging mode, processing the at least two photoacoustic electrical signals to obtain a frame of photoacoustic image includes: 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 average photoacoustic image signal; The average photoacoustic image signal is processed to obtain a frame of photoacoustic image.

11. The method according to claim 7, wherein In the second photoacoustic imaging mode, processing the at least two photoacoustic electrical signals to obtain a frame of photoacoustic image includes: 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 average photoacoustic image signal; The average photoacoustic image signal is processed to obtain a frame of photoacoustic image.

12. A photoacoustic imaging method, characterized in that: include: Detecting the moving speed of the photoacoustic composite probe; Determining the number of laser shots N based on the moving speed; Controlling the photoacoustic composite probe to emit N lasers toward the tissue to be tested; Controlling the photoacoustic composite probe to respectively receive N ultrasonic waves generated by the tissue to be tested under the action of the N laser beams to obtain N photoacoustic electrical signals, wherein the ultrasonic wave generated by the tissue to be tested under the action of one laser beam is one ultrasonic wave, and the photoacoustic electrical signal obtained by receiving one ultrasonic wave is one photoacoustic electrical signal; The N photoacoustic electrical signals are processed to obtain a frame of photoacoustic image.

13. The method according to claim 12, wherein: The detection of the moving speed of the photoacoustic composite probe in the tissue to be tested includes: The moving speed of the photoacoustic composite probe is detected by a sensor provided on the photoacoustic composite probe.

14. The method according to claim 12, wherein: The moving speed of the photoacoustic composite probe is as follows: Acquiring continuous multi-frame ultrasound images of the tissue to be tested by the photoacoustic composite probe; The moving speed of the photoacoustic composite probe on the tissue to be tested is detected by using the continuous multi-frame ultrasound images as the moving speed of the photoacoustic composite probe.

15. The method according to claim 14, wherein The detecting the moving speed of the photoacoustic composite probe on the tissue to be tested by using the continuous multi-frame ultrasound images includes: Identifying a target area in the continuous multi-frame ultrasound image; 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 image.

16. The method according to claim 14, wherein The detecting the moving speed of the photoacoustic composite probe on the tissue to be tested by using the continuous multi-frame ultrasound images includes: Identifying whether the continuous multiple frames of ultrasound images contain a target area; Determining the number of consecutive ultrasound image frames containing the target area in the consecutive multiple ultrasound image frames; The moving speed of the photoacoustic composite probe on the tissue to be measured is determined by the frame number.

17. The method according to claim 16, wherein Identifying whether the continuous multi-frame ultrasound images include a target area and determining the number of frames of the continuous multi-frame ultrasound images that include the target area includes: Identifying frame by frame whether the continuous multiple frames of ultrasound images contain a target area; The counting of the number of image frames starts when the target area is recognized in a frame of ultrasound image. Each time the target area is recognized in a frame of ultrasound image, the number of image frames accumulates by one frame until the counting of the number of image frames stops when the target area is recognized in a frame of ultrasound image. The number of image frames at the time of stopping is determined.

18. The method according to any one of claims 15 to 17, wherein: The target area includes 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 a preset condition.

19. The method according to any one of claims 12 to 17, wherein: Determining the number of laser shots N based on the moving speed includes: The number of laser shots N is determined based on the moving speed and a preset corresponding relationship, wherein the preset corresponding relationship is a corresponding relationship between the moving speed of the photoacoustic composite probe and the number of laser shots N, and the corresponding relationship is a negative correlation.

20. The method of claim 18, wherein: Determining the number of laser shots N based on the moving speed includes: The number of laser shots N is determined based on the moving speed and a preset corresponding relationship, wherein the preset corresponding relationship is a corresponding relationship between the moving speed of the photoacoustic composite probe and the number of laser shots N, and the corresponding relationship is a negative correlation.

21. The method according to any one of claims 12 to 16, wherein: The number N of laser shots is greater than or equal to 1 and less than or equal to 15.

22. The method of claim 18, wherein: The number N of laser shots is greater than or equal to 1 and less than or equal to 15.

23. The method according to any one of claims 12 to 17, wherein: Processing the N photoacoustic signals to obtain a frame of photoacoustic image includes: 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.

24. The method of claim 18, wherein: Processing the N photoacoustic signals to obtain a frame of photoacoustic image includes: 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.

25. The method of claim 19, wherein: Processing the N photoacoustic signals to obtain a frame of photoacoustic image includes: 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.

26. The method of claim 21, wherein: Processing the N photoacoustic signals to obtain a frame of photoacoustic image includes: 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.

27. The method according to any one of claims 12 to 17, wherein: Processing the N photoacoustic signals to obtain a frame of photoacoustic image includes: 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.

28. The method of claim 18, wherein: Processing the N photoacoustic signals to obtain a frame of photoacoustic image includes: 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.

29. The method of claim 19, wherein: Processing the N photoacoustic signals to obtain a frame of photoacoustic image includes: 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.

30. The method of claim 21, wherein Processing the N photoacoustic signals to obtain a frame of photoacoustic image includes: 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.

31. A photoacoustic imaging method, characterized in that: include: Detecting the moving speed of the photoacoustic composite probe; When the moving speed meets a first preset condition, controlling the photoacoustic composite probe not to emit laser light toward the tissue to be measured; When the movement speed meets the second preset condition, the photoacoustic composite probe is controlled to emit laser light to the tissue to be measured, and the photoacoustic composite probe is controlled to receive ultrasonic waves generated by the tissue to be measured under the action of the laser to obtain photoacoustic electrical signals, and the photoacoustic electrical signals are processed to obtain photoacoustic images.

32. The method of claim 31, 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 the second preset threshold.

33. The method according to claim 31 or 32, wherein: When the moving speed satisfies a second preset condition, determining the number of laser shots N based on the moving speed; Controlling the photoacoustic composite probe to emit N lasers toward the tissue to be tested; Controlling the photoacoustic composite probe to respectively receive N ultrasonic waves generated by the tissue to be tested under the action of the N laser beams to obtain N photoacoustic electrical signals, wherein the ultrasonic wave generated by the tissue to be tested under the action of one laser beam is one ultrasonic wave, and the photoacoustic electrical signal obtained by receiving one ultrasonic wave is one photoacoustic electrical signal; The N photoacoustic electrical signals are processed to obtain a frame of photoacoustic image.

34. The method according to any one of claims 31 and 32, wherein: Determining the number of laser shots N based on the moving speed includes: The number of laser shots N is determined based on the moving speed and a preset corresponding relationship, wherein the preset corresponding relationship is a corresponding relationship between the moving speed of the photoacoustic composite probe and the number of laser shots N, and the corresponding relationship is a negative correlation.

35. The method of claim 33, wherein: Determining the number of laser shots N based on the moving speed includes: The number of laser shots N is determined based on the moving speed and a preset corresponding relationship, wherein the preset corresponding relationship is a corresponding relationship between the moving speed of the photoacoustic composite probe and the number of laser shots N, and the corresponding relationship is a negative correlation.

36. A photoacoustic imaging system, characterized in that: include: Laser, photoacoustic composite probe and processor; The laser is used to generate laser light and transmit the laser light to the target tissue through the optical transmission device; The photoacoustic composite probe is used to receive the photoacoustic signal returned from the target tissue; The processor is used to process the photoacoustic signal to obtain a photoacoustic image; The processor is further configured to execute the method described in any one of claims 1 to 35.

37. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method according to any one of claims 1 to 35.

Images