Photoacoustic endoscopic imaging system and method based on polarized light multi-angle rotary scanning

Abstract

The invention provides a photoacoustic endoscopic imaging system and method based on polarized light multi-angle rotary scanning, and belongs to the technical field of photoacoustic imaging, the photoacoustic endoscopic imaging system comprises a control system, a light source system, a light path system, an endoscope probe, a data acquisition system and a data reconstruction system, the control system is connected with the light source system and the data acquisition system, and the light path system is connected with the data reconstruction system. The light source system, the light path system and the endoscope probe are sequentially connected, and the data acquisition system is respectively connected with the endoscope probe and the data reconstruction system; the light path system at least comprises a hollow servo motor and a half-wave plate, and the hollow servo motor is used for responding to the time sequence pulse signal and controlling the half-wave plate to rotate by multiple preset angles so as to adjust the polarization direction of the linearly polarized light. The hollow servo motor and the half-wave plate are combined, the polarization direction of light can be rapidly and accurately adjusted, multi-angle scanning is achieved, the imaging speed is remarkably increased, multiple images can be obtained in a shorter time, and the device is suitable for clinical scenes needing real-time feedback.

Description

Technical Field

[0001] The present invention relates to the technical field of photoacoustic imaging, and in particular to a photoacoustic endoscopic imaging system and method based on multi-angle rotation scanning of polarized light. Background Art

[0002] Photoacoustic imaging is an emerging medical imaging method that combines optical and ultrasonic technologies to achieve high-resolution and high-contrast imaging. Currently, there are two main ways to implement photoacoustic imaging: photoacoustic tomography (PACT) and photoacoustic microscopy. PACT technology is suitable for imaging larger volumes of tissue and can provide higher depth resolution, but in biological tissues with severe light scattering, the imaging quality is easily affected, resulting in blurred images. Photoacoustic microscopy can provide higher spatial resolution and is suitable for imaging tiny structures, but it is limited in imaging depth and cannot penetrate into deeper tissues.

[0003] Traditional photoacoustic imaging systems mostly use a single wavelength laser source. Although 1200 nm lasers can effectively excite photoacoustic signals in biological tissues, the imaging speed and quality are still limited when dealing with complex tissues. Due to the scattering characteristics of light in biological tissues, the attenuation and distortion of signals significantly increase the noise interference in the imaging process, reducing the accuracy and reliability of the final imaging. In addition, existing technologies usually require a long scanning time, which limits their real-time and adaptability in clinical applications, especially in surgical scenarios that require rapid response, and often fail to provide timely imaging feedback. Summary of the invention

[0004] The present invention provides a photoacoustic endoscopic imaging system and method based on polarized light multi-angle rotation scanning, which solves the defects of the existing photoacoustic imaging system that requires a long scanning time and cannot provide timely imaging feedback, significantly improves the speed, resolution and signal quality of biological tissue imaging, and meets the needs of clinical real-time imaging.

[0005] In a first aspect, the present invention provides a photoacoustic endoscopic imaging system based on polarized light multi-angle rotation scanning, comprising a control system, a light source system, an optical path system, an endoscopic probe, a data acquisition system, and a data reconstruction system, wherein the control system is respectively connected to the light source system and the data acquisition system, the light source system, the optical path system, and the endoscopic probe are connected in sequence, and the data acquisition system is respectively connected to the endoscopic probe and the data reconstruction system; The control system is used to generate a timing pulse signal, and control the light source system, the optical path system and the data acquisition system according to the timing pulse signal; The light source system is used to generate a pulsed laser beam of a preset wavelength in response to the timing pulse signal, and convert the pulsed laser beam into linearly polarized light and emit it; The optical path system at least includes a hollow servo motor and a half-wave plate, wherein the hollow servo motor is used to control the half-wave plate to rotate a plurality of preset angles in response to the timing pulse signal to adjust the polarization direction of the linearly polarized light; The endoscope probe is used to process the light beam emitted by the half-wave plate, transmit the processed light beam to the sample, receive the photoacoustic signal fed back by the sample and convert it into an electrical signal; The data acquisition system is used to collect the electrical signal and process the electrical signal in response to the timing pulse signal, and transmit the processed electrical signal to the data reconstruction system; The data reconstruction system is used to generate a sample image according to the received processed electrical signal.

[0006] According to a photoacoustic endoscopic imaging system based on multi-angle rotational scanning of polarized light provided by the present invention, the preset angles include 0°, 22.5°, 45° and 67.5°, and the optical path system also includes a fiber coupler and a fiber collimator, and the fiber coupler and the fiber collimator are used to couple and collimate the linearly polarized light into the optical fiber. Correspondingly, the hollow servo motor is used to control the half-wave plate to rotate between four preset angles to adjust the polarization direction of the linearly polarized light in the optical fiber.

[0007] According to a photoacoustic endoscopic imaging system based on multi-angle rotation scanning of polarized light provided by the present invention, the endoscopic probe includes a MEMS scanning micromirror, a focusing lens, a rod lens group, an objective lens group, a light-transmitting reflective mirror and an ultrasonic transducer arranged in an endoscope housing; the MEMS scanning micromirror is used to quickly modulate and switch the light beam emitted by the half-wave plate to adjust the light beam path and intensity; the focusing lens is used to focus the light beam output by the MEMS scanning micromirror, and the optical parameters of the focusing lens are determined based on the characteristics of the sample; the rod lens group is used to adjust the propagation direction and shape of the light beam output by the focusing lens; the objective lens group is used to perform secondary focusing on the light beam output by the rod lens group; the light-transmitting reflective mirror is used to transmit the light beam output by the objective lens group to the sample and receive the photoacoustic signal fed back by the sample; the ultrasonic transducer is used to convert the photoacoustic signal into an electrical signal.

[0008] According to a photoacoustic endoscopic imaging system based on multi-angle rotation scanning of polarized light provided by the present invention, the focusing lens adopts an aspherical lens, the rod lens group includes a plurality of rod lenses arranged at equal intervals and multi-layer coated, the objective lens group includes a plurality of objective lenses with multi-layer coating and anti-reflection coating, and the endoscope shell is a double-layer structure, the inner layer is a flexible material, and the outer layer is a rigid structure.

[0009] According to a photoacoustic endoscopic imaging system based on multi-angle rotation scanning of polarized light provided by the present invention, the light source system includes a 1200 nm pulsed laser and a linear polarizer. The 1200 nm pulsed laser is used to generate a pulsed laser beam with a wavelength of 1200 nm in response to a timing pulse signal, and the linear polarizer is used to convert the pulsed laser beam into linearly polarized light.

[0010] According to a photoacoustic endoscopic imaging system based on multi-angle rotational scanning of polarized light provided by the present invention, the data reconstruction system is also used to analyze the sample image and quantify the optical properties of the sample in different directions, and the control system is also used to adjust the timing pulse signal according to the optical properties so as to adjust the parameters of the pulsed laser beam.

[0011] According to a photoacoustic endoscopic imaging system based on multi-angle rotational scanning of polarized light provided by the present invention, the sample is arranged in a sample pool, and the sample pool is used to provide a dynamic environment for the sample through the flow of a fluid medium or a gas medium. The sample pool is also provided with a temperature detection unit and a pressure detection unit, which are used to provide different experimental environments for the sample according to the respective detection data of the temperature detection unit and the pressure detection unit.

[0012] According to a photoacoustic endoscopic imaging system based on polarized light multi-angle rotation scanning provided by the present invention, the endoscopic probe, the data acquisition system and the data reconstruction system are connected by a high-speed data transmission interface.

[0013] According to a photoacoustic endoscopic imaging system based on multi-angle rotational scanning of polarized light provided by the present invention, the input end of the data acquisition system is also connected to a signal amplifier and a shock-absorbing bracket for fixing the signal amplifier, and the signal amplifier is used to enhance the electrical signal and output it to the data acquisition system.

[0014] In a second aspect, the present invention further provides a method for photoacoustic endoscopic imaging based on multi-angle rotational scanning of polarized light, which is implemented based on any one of the photoacoustic endoscopic imaging systems based on multi-angle rotational scanning of polarized light, and the method comprises: In response to the timing pulse signal, a pulsed laser beam of a preset wavelength is generated, and the pulsed laser beam is converted into linearly polarized light and emitted; adjusting the polarization direction of the linearly polarized light by means of a half-wave plate switched between a plurality of preset angles; Processing the light beam emitted by the half-wave plate, transmitting the processed light beam to the sample, receiving the photoacoustic signal fed back by the sample and converting it into an electrical signal; In response to the timing pulse signal, the electrical signal is collected and processed and analyzed to generate a sample image.

[0015] The present invention provides a photoacoustic endoscopic imaging system and method based on multi-angle rotational scanning of polarized light, which adopts a combination of a hollow servo motor and a half-wave plate, can quickly and accurately adjust the polarization direction of light, realize multi-angle scanning, significantly improve the imaging speed, and can obtain multiple images in a shorter time, which is suitable for clinical scenarios requiring real-time feedback. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 The present invention provides a circuit diagram of a photoacoustic endoscopic imaging system based on multi-angle rotation scanning of polarized light.

[0018] Figure 2 It is a schematic diagram of the preset angle of the half-wave plate provided by the present invention and the polarization direction corresponding to the preset angle.

[0019] Figure 3 It is a side structural schematic diagram of the hollow servo motor and the half-wave plate provided by the present invention.

[0020] Figure 4 It is a three-dimensional structural schematic diagram of the hollow servo motor and the half-wave plate provided by the present invention.

[0021] Figure 5 It is a schematic flow chart of the photoacoustic endoscopic imaging method based on multi-angle rotation scanning of polarized light provided by the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] It should be noted that in the description of the present invention, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "include one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements. The orientation or position relationship indicated by the terms "upper", "lower" and the like is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] The terms "first", "second", etc. in the present invention are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present invention can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" means at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0025] All actions of acquiring signals, information or data in the present invention are performed under the premise of complying with the corresponding data protection laws and policies of the location and with the authorization given by the owner of the corresponding device.

[0026] A photoacoustic endoscopic imaging system and method based on multi-angle rotation scanning of polarized light provided by the present invention will be described below in conjunction with the accompanying drawings.

[0027] Figure 1 Schematic diagram of the circuit of the photoacoustic endoscopic imaging system based on polarized light multi-angle rotation scanning provided by the present invention. Figure 1As shown, the present invention provides a photoacoustic endoscopic imaging system based on polarized light multi-angle rotation scanning, including a control system 1, a light source system, an optical path system, an endoscopic probe, a data acquisition system and a data reconstruction system, wherein the control system 1 is connected to the light source system and the data acquisition system respectively, the light source system, the optical path system and the endoscopic probe are connected in sequence, and the data acquisition system is connected to the endoscopic probe and the data reconstruction system respectively. The above-mentioned system is connected through optical fibers, optical elements or electronic signal lines to ensure efficient transmission and processing of information; the light source system is fixed on the upper part of the device, the optical path system is located in the center, the endoscopic probe extends to the detection area, and the data acquisition system and the data reconstruction system are located on the operating table for user operation and monitoring.

[0028] The control system 1 is used to generate a timing pulse signal, and control the light source system, the optical path system and the data acquisition system according to the timing pulse signal.

[0029] The light source system is used to generate a pulsed laser beam of a preset wavelength in response to the timing pulse signal, and convert the pulsed laser beam into linearly polarized light for emission.

[0030] The optical path system at least includes a hollow servo motor 6 and a half-wave plate 7. The hollow servo motor 6 is used to control the half-wave plate 7 to rotate a plurality of preset angles in response to the timing pulse signal to adjust the polarization direction of the linear polarized light. The hollow servo motor 6 quickly changes the polarization state of the light beam and optimizes the imaging effect on the sample by controlling the rotation speed and rotation angle of the half-wave plate 7. The hollow servo motor 6 is connected to the half-wave plate 7 and driven by the control system 1 to ensure that the movement of the motor can accurately control the angle of the half-wave plate 7 so as to quickly switch between fixed positions of several preset angles, so that the polarization direction of the linear polarized light changes accordingly, thereby affecting the penetration and scattering behavior of the light in the sample.

[0031] The endoscope probe is used to process the light beam emitted by the half-wave plate 7, transmit the processed light beam to the sample 14, receive the photoacoustic signal fed back by the sample and convert it into an electrical signal. Optionally, the light beam emitted by the half-wave plate 7 is incident on the endoscope probe via the reflector 8 to reduce the volume of the endoscope probe.

[0032] The data acquisition system is used to respond to the timing pulse signal, collect the electrical signal and process the electrical signal, and transmit the processed electrical signal to the data reconstruction system. The data acquisition system includes an acquisition card 17, which converts the analog signal in the electrical signal into a digital signal for subsequent processing.

[0033] The data reconstruction system is used to generate a sample image based on the received processed electrical signal. The data reconstruction system can be formed by a computer PC terminal 18, and a data acquisition system is connected to the endoscope probe to receive the electrical signal output by the endoscope probe, and convert the received analog signal into a digital signal for subsequent processing, and the converted digital signal is transmitted to the computer PC terminal through a high-speed interface for further processing; the computer PC terminal 18 receives the digital signal from the data acquisition system and analyzes it through data processing software.

[0034] As an optional embodiment, the material of the half-wave plate 7 is selected to be a single crystal material with high optical quality to ensure that it does not cause light scattering or distortion when rotating at high speed, thereby ensuring that the direction of the polarized light changes accurately and stably.

[0035] As an optional embodiment, the data reconstruction system is also used to analyze the sample image and quantify the optical properties of the sample in different directions. The control system 1 is also used to adjust the timing pulse signal according to the optical properties so as to adjust the parameters of the pulsed laser beam. The control system 1 adopts a real-time feedback mechanism and can automatically adjust the parameters and scanning speed of the laser beam according to the characteristics of the sample to optimize the imaging effect.

[0036] The present invention can realize unified and precise control of the light source system, the optical path system and the data acquisition system through the timing pulse signal generated by the control system 1, and reduce the errors between the light source system, the optical path system and the data acquisition system. The control system 1 can be composed of an FPGA board to receive the rotation angle command input by the host computer. The hollow servo motor 6 is equipped with a high-precision encoder inside to monitor the rotation angle in real time and transmit the feedback signal to the control system 1. The control system 1 adjusts the current through PWM to drive the motor to rotate to the target angle, and ensures the precise rotation of the motor through a closed-loop control mechanism to achieve high-precision control with an angle error of less than 0.1°. The present invention uses precise feedback and closed-loop control mechanisms, which will significantly improve the accuracy of angle conversion, and help to improve the precise regulation of polarized light and the resolution of the final imaging.

[0037] Specifically, the rotation of the hollow servo motor 6 is achieved with the cooperation of the upper computer and the lower computer. Input parameters such as target angle and target speed in the upper computer interface, and send instructions to the lower computer FPGA through the serial port. The lower computer converts the target angle into a rotation signal of the servo motor and controls the rotation of the servo motor. The motor encoder monitors the rotation angle in real time and feeds back the actual position to the lower computer. The lower computer corrects the error to ensure accurate positioning.

[0038] Specific control process of the lower computer: FPGA generates a PWM signal with a certain duty cycle (pulse width ratio); The frequency of the PWM signal determines the motor speed, and the duty cycle determines the output current intensity; after the driver receives the PWM signal, it converts it into the motor coil current to drive the motor to rotate; the FPGA generates a series of pulse signals with a fixed frequency; each pulse drives the motor to rotate a basic step angle (the basic step angle is determined by the motor manufacturing process and physical properties); by adjusting the number and frequency of pulses, the total rotation angle and speed can be controlled.

[0039] Pulse number calculation: Target pulse number = target angle * encoder resolution / 360° In addition, the encoder returns the current angle (expressed in pulse counts) in real time; the FPGA compares the actual pulse count with the target pulse count and dynamically adjusts the drive signal.

[0040] It can be understood that the present invention adopts a combination of a hollow servo motor 6 and a half-wave plate 7, which can quickly and accurately adjust the polarization direction of light, realize multi-angle scanning, significantly improve the imaging speed, and can obtain multiple images in a shorter time, which is suitable for clinical scenarios that require real-time feedback.

[0041] Based on the above embodiment, as an optional embodiment, the light source system includes a 1200nm pulse laser 2 and a linear polarizer 3, wherein the 1200nm pulse laser 2 is used to generate a pulse laser beam with a wavelength of 1200 nm in response to a timing pulse signal, and the linear polarizer 3 is used to convert the pulse laser beam into linearly polarized light.

[0042] Optionally, the 1200nm pulsed laser 2 has a high peak power, with a typical peak power of 500 mW, and can quickly excite photoacoustic signals in biological tissues. Furthermore, the laser is fixed to a light source bracket to ensure that it remains stable during emission. The linear polarizer 3 is used to convert the laser beam into linear polarized light to increase the coherence of the light. The polarizer is connected to the laser through an optical fixture, and its angle can be adjusted to meet different experimental requirements, and is fixed at the entrance of the optical path system.

[0043] It is understandable that the linear polarizer 3 provided by the present invention has the characteristics of high light transmittance and low optical distortion to maximize the imaging quality. The present invention takes into account the characteristics of different samples and can adapt to different imaging requirements by replacing different types of linear polarizers 3, half-wave plates 7 and lens combinations.

[0044] Figure 2 Schematic diagram of the preset angle of the half-wave plate 7 provided by the present invention and the polarization direction corresponding to the preset angle, such as Figure 2As shown, based on the above embodiment, as an optional embodiment, the preset angles include 0°, 22.5°, 45° and 67.5°, which are the angles at which the motor drives the half-wave plate to rotate, corresponding to the four light polarization states (0°, 45°, 90°, 135°) required to be output. When light with different polarization angles passes through the tissue, it will show different absorption or scattering behaviors. By collecting photoacoustic signals at polarization angles of 0°, 45°, 90° and 135°, the optical anisotropy information of the sample in different directions can be revealed. 0° and 90° represent the limit states of horizontal polarization and vertical polarization, respectively, and 45° and 135° represent the oblique states of linear polarization, which are diagonal states in the horizontal and vertical directions. These four angles can provide the maximum degree of optical property changes, covering the characteristics of all major polarization directions in the sample. One of the main applications of polarized light is through polarization parameter fitting, such as birefringence parameters and extinction rate. By combining the photoacoustic signals at 0°, 45°, 90°, and 135°, polarization properties, such as phase delay caused by polarization-dependent absorption or birefringence effects, can be reconstructed. These four angles provide a complete sampling of the linear polarization state, which facilitates the subsequent calculation of polarization information using Malus's law or other polarization analysis models. Selecting the four angles of 0°, 45°, 90°, and 135° can achieve maximum information coverage at fewer angles, reduce system complexity, and ensure measurement accuracy. Too many angles will increase the difficulty of data processing, while too few angles may not fully reflect the optical properties of the sample.

[0045] The optical path system also includes a fiber coupler 4 and a fiber collimator 5, and the fiber coupler 4 and the fiber collimator 5 are used to couple and collimate the linearly polarized light into the optical fiber. Correspondingly, the hollow servo motor 6 is used to control the half-wave plate 7 to rotate between four preset angles to adjust the polarization direction of the linearly polarized light in the optical fiber.

[0046] The fiber coupler 4 and the fiber collimator 5 effectively couple and collimate the laser, and high-quality fiber couplers 4 and collimators are used to minimize light loss. The fiber coupler 4 and the fiber collimator 5 are fastened to the front end of the optical path system and connected to the laser and the linear polarizer 3 through a single-mode optical fiber.

[0047] The focal length of the present invention is 50 mm, which ensures that the light beam can propagate in parallel. The hollow servo motor 6 is a key component, model HO3507, and has high-precision control capabilities. The motor is installed at the center of the optical path system to drive the rotation of the half-wave plate 7 to ensure the stability of the light beam during rotation. The half-wave plate 7 is fixed on the output shaft of the motor, has a thickness of 1 mm, and is made of optical quartz. The rotation angle range of the half-wave plate 7 is 0° to 67.5°, and its main function is to adjust the polarization direction of the incident light so that the light beam enters the probe at different angles. The rotation of the motor is adjusted in real time by the motor control system 1.

[0048] Figure 3 : is a side structural schematic diagram of the hollow servo motor 6 and the half-wave plate 7 provided by the present invention, Figure 4 Schematic diagram of the three-dimensional structure of the hollow servo motor 6 and the half-wave plate 7 provided by the present invention, as shown in Figure 3 and Figure 4 As shown, the hollow servo motor 6 is configured in the optical path system to drive the rapid rotation of the half-wave plate 7. Furthermore, the output shaft of the motor is connected to the mounting base of the half-wave plate 7 through a special bearing to ensure that it remains stable during rotation and avoids vibration. The half-wave plate 7 is used to adjust the polarization direction of the incident light to achieve multi-directional scanning of the sample. The half-wave plate 7 is fixed on the 3D bracket 19 and fixedly connected to the output shaft of the motor with screws (such as 4 M2 screws) to ensure that it moves smoothly when the motor rotates and has precise angle adjustment capabilities.

[0049] The present invention ensures that the sample is fully imaged at multiple polarization angles such as 0°, 45°, 90°, and 135° by means of rotational scanning, thereby improving the coverage of the sample. Compared with single-angle imaging, the morphology and internal structural characteristics of the sample can be more comprehensively displayed; through rotational scanning, photoacoustic signals can be collected at different polarization angles to analyze the optical anisotropy of the sample, which is particularly suitable for the detection of optical properties of fibrous tissues. This design can accurately reveal the differences in optical characteristics of the sample in different directions and provide more sample information; through multiple rotational scanning, the system can image the same target area multiple times to improve the signal-to-noise ratio and resolution of the image. This multi-angle imaging technology can enhance the presentation of sample details, and is particularly suitable for the identification and analysis of complex microstructures; the system obtains multi-angle images of the sample through rotational scanning at different angles, and performs three-dimensional reconstruction through image superposition, which can accurately display the three-dimensional structure of the sample; through optical scanning at different polarization angles, the system can quantify the optical properties of the sample in various directions, such as absorption coefficient and scattering coefficient. This quantitative analysis provides more information for the assessment of tissue health, and is particularly suitable for optical property analysis in disease diagnosis.

[0050] As an optional embodiment, the control system 1 provided by the present invention integrates an artificial intelligence algorithm, which can automatically adjust system parameters according to sample characteristics and imaging results to improve the intelligence and adaptability of imaging. The processing algorithm adopts a deep learning model to improve the feature extraction capability of complex samples and enhance the analysis accuracy of imaging data. The control system 1 is also used to quickly image multiple samples, integrate their data, and generate high-resolution composite images using image stitching technology to more comprehensively analyze sample characteristics.

[0051] The impact of different polarization directions on the algorithm for generating sample images is mainly reflected in image processing, optical property extraction and multi-dimensional information fusion.

[0052] 1. After light with different polarization directions enters the sample, it interacts with the microstructure in the sample (such as collagen fibers, muscle fibers, cell membranes, etc.), causing different optical changes, such as absorption rate, scattering characteristics, birefringence effect, polarization retention, etc. These changes reflect the microstructure and composition differences of the sample and are an important basis for imaging algorithm analysis.

[0053] 2. The intensity of photoacoustic imaging signals in different polarization directions varies due to the anisotropy of the optical properties inside the sample. The algorithm needs to analyze the signal differences at each polarization angle and optimize the image contrast to highlight the optical properties in a specific direction, such as the orientation and absorption properties of collagen fibers.

[0054] 3. Photoacoustic images at multiple polarization angles may have spatial displacement or angle deviation. The algorithm needs to perform image registration and accurately superimpose the images at each angle. Afterwards, the image fusion technology is used to integrate the information at each angle into a high-resolution, multi-dimensional composite image, thereby improving the overall performance of the imaging.

[0055] The photoacoustic imaging algorithm of the image processing part of the present invention includes decoupling of polarized photoacoustic signals, quantitative analysis of polarization characteristics, image reconstruction and fusion, and generation of polarization characteristic diagrams. It can fuse and process photoacoustic data at multiple polarization angles and generate high-resolution imaging data, thereby extracting optical characteristic information of the sample.

[0056] 1. Decoupling of polarized photoacoustic signals Using photoacoustic signals with different polarization angles (0°, 45°, 90°, 135°), the total photoacoustic signal can be decomposed into polarization-dependent components and polarization-independent components. The definitions are as follows: in: is the photoacoustic signal at a certain polarization angle θ, is the polarization-dependent photoacoustic signal component, It is the photoacoustic signal component that is independent of polarization.

[0057] 2. Quantitative analysis of polarization characteristics Introducing the polarization contrast parameter (Polarization Contrast, ): This parameter reflects the changes in the photoacoustic response of the sample at different polarization angles and quantitatively describes the anisotropic properties of the sample.

[0058] 3. Image reconstruction and fusion For each polarization angle, the photoacoustic signal , using traditional photoacoustic imaging reconstruction algorithms (such as Delay-and-Sum, DAS) for preliminary image reconstruction: in: is the reconstruction intensity corresponding to position r, is a weight function (which can be set based on distance or signal-to-noise ratio), is the signal i at the corresponding time The value of .

[0059] After obtaining images at different angles, a comprehensive image is obtained through the polarization spectrum fusion algorithm: in: is the weight factor for the polarization angle, which can be calculated based on Dynamically adjusts to enhance areas with significant polarization properties.

[0060] 4. Polarization characteristic diagram generation Based on the images at each polarization angle, a polarization direction map (PDM) is generated: The figure shows the main polarization response directions at each position of the sample, intuitively demonstrating the anisotropic distribution of the sample.

[0061] Compared with the existing photoacoustic imaging algorithms, the present invention has the following advantages: 1. The decoupling processing of polarization-related components has been added, which improves the ability to extract the anisotropy information of the sample.

[0062] 2. Combining polarization contrast and directional characteristics, a polarization spectrum fusion algorithm is added for image post-processing.

[0063] 3. Provides a polarization direction characteristic diagram, which can intuitively reflect the polarization response of the internal microstructure of the sample.

[0064] In this way, the present invention can more comprehensively analyze the optical properties in biological tissues, especially the orientation and density distribution of collagen fibers.

[0065] It can be understood that the present invention uses multiple polarization angles (0°, 45°, 90°, 135°) to quickly image the sample four times, and through algorithm registration, the image quality can be optimized. The imaging data of each polarization angle carries different optical property information, and the multi-angle imaging and polarization information are integrated. The computer's image processing algorithm generates a high-resolution image with richer optical properties (such as polarization information) by fusing and splicing these multi-angle imaging data. The multi-angle polarization imaging technology provided by the present invention can more comprehensively and accurately characterize the anisotropy and optical properties of the sample. On the other hand, the imaging of the present invention is not only based on ordinary photoacoustic signals, but also combines polarization light information to extract the optical properties of the sample through a specific algorithm, adding an additional polarization data dimension, and providing innovative data support for the fine analysis of the internal tissue structure and optical properties of the sample. By introducing the fusion processing of multi-angle polarization information and a dedicated image processing algorithm, the present invention has significant technical innovations in image quality, information extraction and processing speed.

[0066] The present invention realizes the following functions: 1. Automatic rotation angle adjustment: Compared with manual or simple motor-driven systems, the present invention realizes automatic control of the motor through the coordinated work of the upper computer and the lower computer, reduces the error caused by human intervention, and improves the usability of the equipment.

[0067] 2. Multi-angle polarization control: In the existing technology, the motor can only drive a fixed angle, but this system can achieve multi-angle adjustment through software control, especially multiple different polarization angles, making the control of the light beam more flexible and providing richer optical information for imaging.

[0068] 3. Full-angle coverage: The system covers polarization directions of 0°, 45°, 90°, and 135° through four imaging at different angles, which can more comprehensively obtain the anisotropic optical properties of the sample, while existing technologies may only cover a single or limited polarization angle range.

[0069] 4. Automated control logic: The existing systems often require manual adjustment or multi-component collaboration to adjust the optical path. This system reduces complex physical adjustments and improves the smoothness of the imaging process through automatic control between host computer instructions and motors.

[0070] 5. Enhanced sample analysis capabilities: Through the changes in polarized light from four imagings, the system can effectively detect and quantify the differences in the optical properties of samples in different directions. This is difficult to achieve through simple beam changes in existing technologies, greatly expanding the application range and detection depth of the system.

[0071] Based on the above embodiment, as an optional embodiment, the endoscope probe includes a MEMS scanning micromirror 9, a focusing lens 10, a rod lens group 11, an objective lens group 12, a light-transmitting acoustic mirror 13 and an ultrasonic transducer 15 arranged in an endoscope housing.

[0072] The MEMS scanning micromirror 9 is used to quickly modulate and switch the light beam emitted by the half-wave plate 7 to adjust the light beam path and intensity; high-speed light beam adjustment can be achieved. By controlling the MEMS scanning micromirror 9, the light path and intensity can be changed. The MEMS scanning micromirror 9 is located at the rear end of the optical path system and before the focusing lens 10. It receives the modulated light beam from the light source system and transmits the modulated light beam to the focusing lens 10. The MEMS scanning micromirror 9 is used to quickly adjust the scanning range and is located downstream of the optical path system. This component realizes real-time response through a micromechanical system, is connected to the optical lens part, and is fixed by a lightweight bracket to reduce interference with the light path.

[0073] The focusing lens 10 is used to focus the light beam output by the MEMS scanning micromirror 9. The optical parameters of the focusing lens 10 are determined based on the characteristics of the sample. The focusing lens 10 focuses the modulated light beam onto the sample to ensure that the light beam effectively irradiates the target area, thereby improving the resolution and contrast of the imaging. The focusing lens 10 is located after the MEMS scanning micromirror 9 and receives the light beam from the MEMS scanning micromirror 9. Its optical parameters (such as focal length) need to be selected according to the characteristics of the sample to ensure the best focusing effect. Beam profile detection is often used in experiments: Use a beam analyzer or camera to detect the beam profile to ensure that the shape, size and uniformity of the beam after focusing meet the experimental requirements. This method helps optimize the focal length of the lens and the collimation effect of the beam by accurately measuring the intensity distribution and shape of the beam. The focusing lens 10 uses high-quality optical glass with a focal length of 15 mm to ensure that the beam is focused on the detection area. The lens is connected to the optical path system through an optical fiber and fixed to the front of the probe.

[0074] The rod lens group 11 is used to adjust the propagation direction and shape of the light beam output by the focusing lens 10; the rod lens group 11 is used to adjust the propagation direction and shape of the light beam, improve the uniformity and focusing quality of the light beam, correct any deviation in the optical path, and ensure the stable transmission of the light beam. The rod lens group 11 is located after the focusing lens 10 and receives the focused light beam. The rod lens group 11 is used to further adjust the direction and propagation of the light beam, and the objective lens group 12 is responsible for forming the final image.

[0075] The objective lens group 12 is used to perform secondary focusing on the light beam output by the rod lens group 11; the objective lens group 12 is responsible for further focusing and imaging the light beam, and it provides the required magnification and resolution to capture the details of the sample and form a high-quality image. The objective lens group 12 is located after the rod lens group 11 and directly receives the optimized light beam. The objective lens group 12 has a design with a magnification of 10× to ensure the acquisition of clear tissue images.

[0076] The light-transmitting acoustic mirror 13 is used to transmit the light beam output by the objective lens group 12 to the sample and receive the photoacoustic signal fed back by the sample; the light-transmitting acoustic mirror 13 allows the laser beam to pass smoothly, ensuring that the light signal required for imaging can be effectively transmitted to the sample, and at the same time reflects the photoacoustic signal from the sample, ensuring that these signals can be effectively transmitted to the ultrasonic transducer 15. The light-transmitting acoustic mirror 13 is located after the objective lens group 12, directly receiving the light beam focused by the objective lens group 12, and its reflecting surface reflects the photoacoustic signal generated by the sample to the ultrasonic transducer 15, so that it can be effectively received and converted into an electrical signal. The light-transmitting acoustic mirror 13 is used to reflect the acoustic signal and transmit the light signal at the same time. It is installed at the front end of the probe and connected in a straight line with the focusing lens 10 to maximize the transmittance of light. The lens has high reflectivity and transmittance to ensure signal quality.

[0077] The ultrasonic transducer 15 is used to convert the acoustic signal into an electrical signal. The main function of the ultrasonic transducer 15 is to receive photoacoustic signals and convert them into electrical signals. These signals are used for data acquisition and subsequent image reconstruction. The ultrasonic transducer 15 is directly connected to the reflective light path of the light-transmitting reflective mirror 13 and is connected to the data acquisition system to realize real-time signal processing. The ultrasonic transducer 15 is fixed to the light-transmitting reflective mirror 13 by gluing and is responsible for converting the acoustic signal into an electrical signal. The operating frequency of this component is 5 MHz, which can effectively capture the changes in acoustic waves in tissues.

[0078] The focusing lens 10, the rod lens group 11 and the objective lens group 12 are jointly responsible for focusing the light signal and forming a clear image. The laser aligner and the adjustment screw are used for precise positioning and fixing to ensure that high-resolution images can be obtained in tissues at different depths.

[0079] The light-transmitting reflective mirror 13 transmits light signals and reflects sound signals at the same time, thereby enhancing signal collection efficiency. The mirror is installed at the front end of the endoscope probe and is connected to the optical system and the ultrasonic transducer 15 through an optical bracket to ensure its stability during imaging.

[0080] The ultrasonic transducer 15 is used to receive the photoacoustic signal and convert it into an electrical signal. The transducer is fixed to a suitable position of the probe by gluing or threading to ensure that it can effectively capture the acoustic signal.

[0081] The endoscope housing provides structural support and protection, ensuring the stability and reliability of the internal optical components.

[0082] As an optional embodiment, the focusing lens 10 adopts an aspheric lens, which can accurately control the focusing point of lasers of different wavelengths, reduce spherical aberration and chromatic aberration, and improve the clarity of sample imaging. The rod lens group 11 includes a number of rod lenses arranged at equal intervals and multi-layer coated to reduce light loss and improve the stability and uniformity of light beam transmission. The objective lens group 12 includes a number of multi-layer coated objective lenses with anti-reflection coatings to reduce the interference of multiple internal reflections on imaging. The light-transmitting reflective mirror 13 can simultaneously improve the transmittance of light and the reflection efficiency of acoustic signals through a photoacoustic lens structure at a specific angle, thereby improving the photoacoustic signal collection effect. The endoscope shell is a double-layer structure, the inner layer is a flexible material, and the outer layer is a rigid structure. It has durability and flexible operability, and has a heat dissipation channel to ensure heat discharge during long-term operation.

[0083] It can be understood that the endoscopic probe provided by the present invention has a small and compact structure and is suitable for detection in a small space. The probe integrates high-precision optical elements such as a focusing lens 10, a rod lens group 11, and an objective lens group 12, and realizes efficient transmission of photoacoustic signals through a light-transmitting reflective mirror 13 to ensure high-resolution endoscopic imaging quality; the system accurately controls the rotation of the half-wave plate 7 through a motor to achieve multi-angle scanning, which is particularly suitable for complex endoscopic application scenarios, and performs high-resolution imaging in the body or in inaccessible tissues, thereby improving diagnostic accuracy; the endoscopic system optimizes the optical path design to ensure that light is transmitted in a complex in vivo environment. Efficient transmission, and through the cooperation of the transparent reflective mirror 13 and the ultrasonic transducer 15, efficient reflection and collection of photoacoustic signals are achieved to generate clear endoscopic images; the endoscopic imaging system of the present invention uses polarized light technology to perform anisotropy analysis on tissues, thereby enhancing the ability to recognize the optical properties of tissues, and is particularly suitable for quantitative analysis of optical properties in different directions in a narrow endoscopic environment, providing rich diagnostic information; the endoscopic system accurately controls the rotation of the half-wave plate 7 through a motor to achieve multi-angle polarized light imaging, which can adapt to the complex endoscopic imaging requirements of different tissue structures and improve the flexibility and accuracy of imaging.

[0084] Based on the above embodiment, as an optional embodiment, the sample is set in a sample pool, the sample pool is used to provide a dynamic environment for the sample through the flow of a fluid medium or a gas medium, and the sample pool is also provided with a temperature detection unit and a pressure detection unit, which are used to provide different experimental environments for the sample according to the detection data of the temperature detection unit and the pressure detection unit. Specifically, the intensity and frequency of the pulsed laser beam can be adjusted to optimize the irradiation conditions of the sample to achieve the best photoacoustic signal response.

[0085] The design of the sample pool allows the flow of fluid or gas media so that samples can be imaged under dynamic conditions, thereby improving the real-time monitoring capability of biological samples or chemical reaction processes. In addition, the structural design of the sample pool has temperature and pressure monitoring functions to adjust experimental conditions in real time and ensure the stability of sample imaging.

[0086] On the basis of the above embodiment, as an optional embodiment, the endoscope probe, the data acquisition system and the data reconstruction system are connected by a high-speed data transmission interface, which can ensure the real-time acquisition and processing of the photoacoustic signal and reduce the data transmission delay. The control system 1 of the hollow servo motor 6 is realized by the host computer through the following detailed process: the host computer is connected to the motor drive module through an interface such as USB, RS-232 or Ethernet. Usually, the drive module supports the UART communication protocol, which is convenient for sending control signals. The user enters control parameters on the interface of the host computer, such as the target rotation angle (0°, 22.5°, 45°, 67.5°) and the rotation speed. The host computer generates corresponding control instructions according to the parameters entered by the user. These instructions include the frequency and duty cycle of the PWM signal, which are used to control the speed and direction of the motor. The host computer sends the generated control instructions to the motor drive module through the serial port or network. The drive module parses the instructions and generates a motor control signal. The motor drive module adjusts the rotation angle and speed of the motor according to the received signal, and the hollow servo motor 6 starts to rotate at the set angle.

[0087] Based on the above embodiment, as an optional embodiment, the input end of the data acquisition system is also connected to a signal amplifier 16 and a shock-absorbing bracket for fixing the signal amplifier 16, and the signal amplifier 16 is used to enhance the electrical signal and output it to the data acquisition system.

[0088] The data acquisition system is used to perform analog-to-digital conversion on the received electrical signal, and should have a high sampling rate and high resolution to meet the needs of real-time imaging. A high-precision acquisition card 17 can be selected, which has a 16-bit analog-to-digital conversion capability and can quickly process the signal transmitted from the ultrasonic transducer 15. The connection method is a USB interface, which is convenient for connection with the computer PC terminal 18. The acquisition card 17 is fixed in the data processing unit to ensure a stable connection with the signal amplifier 16.

[0089] The signal amplifier 16 is used to enhance the signal strength to improve the signal-to-noise ratio, and has a good gain range and bandwidth to adapt to different types of signals. The amplifier is connected to the acquisition card 17 via a cable and is fixed with a shock-absorbing bracket to prevent external interference.

[0090] The computer PC terminal 18 is equipped with a high-performance processor and a large memory, and receives data from the acquisition card 17 in real time. The software functions include image stitching, registration and post-processing, and adopts advanced image processing algorithms to achieve efficient data analysis. Users operate through an intuitive graphical interface. The computer PC terminal 18 is responsible for real-time data processing and imaging reconstruction, and has high processing power and large memory to support complex image processing algorithms. Its main functions include receiving signals from the acquisition card 17, stitching, registration and post-processing of multiple acquired images, and generating high-quality comprehensive images.

[0091] Furthermore, the computer PC 18 can also perform image analysis, extract tissue structure information, and provide a user-friendly interface for monitoring and operation. Through a high-speed data transmission interface, it ensures a stable connection with the signal amplifier 16, realizes real-time imaging feedback and data recording, and further enhances the practicality and flexibility of the system.

[0092] In summary, the present invention has the following advantages: 1. Compared with the traditional photoacoustic endoscope system, the present invention adopts a combination of a hollow servo motor 6 and a half-wave plate 7, which can quickly and accurately adjust the polarization direction of light and realize multi-angle scanning. This design significantly improves the imaging speed, can obtain multiple images in a shorter time, and is suitable for clinical scenarios that require real-time feedback. In addition, through the flexible configuration of the MEMS scanning micromirror 9 component, the scanning range can be quickly adjusted, further improving the response speed of the system in different applications. This real-time performance enables doctors to make diagnoses faster and optimize clinical decisions, especially providing great convenience in emergency situations.

[0093] 2. The present invention optimizes the design of the optical path system and combines the precise layout of the focusing lens 10, the rod lens group 11 and the objective lens group 12 to ensure efficient focusing of the light beam and imaging clarity. Compared with the prior art, the system can effectively reduce the scattering and loss of light during the imaging process, thereby improving the imaging resolution. In addition, the combined design of the light-transmitting reflective mirror 13 and the ultrasonic transducer 15 ensures the effective capture of the acoustic signal and improves the quality and reliability of the signal. This high signal-to-noise ratio imaging result helps to more accurately identify the microstructure of the tissue and improves the detection capability of the lesion area, which is particularly important for clinical applications.

[0094] 3. The design of the present invention fully considers the flexibility and scalability of the system. Through modular design, each part (light source system, optical path system, endoscope probe and data acquisition and reconstruction system) can be flexibly combined and configured according to different application requirements. The control system 1 integrates advanced data processing functions, which can not only monitor the operating status of each part in real time, but also support complex image processing and analysis tasks. This highly integrated design can reduce the size and weight of the equipment, improve the comfort of patients, and also facilitate the operation of doctors in clinical environments. In addition, the open design of the system allows for future upgrades or expansions to adapt to emerging medical technology needs, ensuring that the system remains competitive in the rapidly developing medical field.

[0095] The following is a description of the photoacoustic endoscopic imaging method based on polarized light multi-angle rotation scanning provided by the present invention. The photoacoustic endoscopic imaging method based on polarized light multi-angle rotation scanning described below and the photoacoustic endoscopic imaging system based on polarized light multi-angle rotation scanning described above can be referenced to each other.

[0096] Figure 5 is a schematic flow chart of a photoacoustic endoscopic imaging method based on polarized light multi-angle rotation scanning provided by the present invention, such as Figure 5 As shown, the present invention provides a photoacoustic endoscopic imaging method based on polarized light multi-angle rotation scanning, which is implemented based on any of the photoacoustic endoscopic imaging systems based on polarized light multi-angle rotation scanning, and the method includes the following steps.

[0097] Step S100, in response to the timing pulse signal, a pulsed laser beam of a preset wavelength is generated, and the pulsed laser beam is converted into linearly polarized light and emitted. Specifically, a laser beam with a wavelength of 1200 nm is emitted, and the laser beam is converted into linearly polarized light through a linear polarizer to ensure high contrast of the beam in the subsequent imaging process. The linearly polarized light is coupled and collimated to the optical path system to ensure that the propagation path of the beam is clear and undistorted.

[0098] Step S200, adjusting the polarization direction of the linear polarized light by switching a half-wave plate between multiple preset angles; changing the polarization state of the linear polarized light by a half-wave plate, wherein the half-wave plate can be quickly switched between 0°, 22.5°, 45° and 67.5° to provide multiple polarization states. The half-wave plate is quickly rotated using a hollow servo motor to achieve laser beams with different polarization angles, thereby improving the imaging quality of the sample.

[0099] Step S300, processing the light beam emitted by the half-wave plate, transmitting the processed light beam to the sample, receiving the photoacoustic signal fed back by the sample and converting it into an electrical signal. Focusing the laser beam into the sample pool, irradiating the sample to be tested; receiving the photoacoustic signal generated by the sample, and converting it into an electrical signal.

[0100] Step S400, in response to the timing pulse signal, the electrical signal is collected and processed and analyzed to generate a sample image. The electrical signal is processed and analyzed by a computer PC to generate high-resolution imaging data of the sample and extract relevant optical property information of the sample.

[0101] The photoacoustic endoscopic imaging method based on polarized light multi-angle rotation scanning provided by the present invention has the technical effect corresponding to that of the photoacoustic endoscopic imaging system based on polarized light multi-angle rotation scanning, which will not be described in detail.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A photoacoustic endoscopic imaging system based on multi-angle rotation scanning of polarized light, characterized in that: It includes a control system, a light source system, an optical path system, an endoscopic probe, a data acquisition system and a data reconstruction system, wherein the control system is connected to the light source system and the data acquisition system respectively, the light source system, the optical path system and the endoscopic probe are connected in sequence, and the data acquisition system is connected to the endoscopic probe and the data reconstruction system respectively; The control system is used to generate a timing pulse signal, and control the light source system, the optical path system and the data acquisition system according to the timing pulse signal; The light source system is used to generate a pulsed laser beam of a preset wavelength in response to the timing pulse signal, and convert the pulsed laser beam into linearly polarized light and emit it; The optical path system at least includes a hollow servo motor and a half-wave plate, wherein the hollow servo motor is used to control the half-wave plate to rotate a plurality of preset angles in response to the timing pulse signal to adjust the polarization direction of the linearly polarized light; The endoscope probe is used to process the light beam emitted by the half-wave plate, transmit the processed light beam to the sample, receive the photoacoustic signal fed back by the sample and convert it into an electrical signal; The data acquisition system is used to collect the electrical signal and processing the electrical signal, and transmitting the processed electrical signal to the data reconstruction system; The data reconstruction system is used to generate a sample image according to the received processed electrical signal.

2. The photoacoustic endoscopic imaging system based on polarized light multi-angle rotation scanning according to claim 1, characterized in that: The preset angles include 0°, 22.5°, 45° and 67.5°. The optical path system also includes a fiber coupler and a fiber collimator. The fiber coupler and the fiber collimator are used to couple and collimate the linearly polarized light into the optical fiber. Correspondingly, the hollow servo motor is used to control the half-wave plate to rotate between four preset angles to adjust the polarization direction of the linearly polarized light in the optical fiber.

3. The photoacoustic endoscopic imaging system based on polarized light multi-angle rotation scanning according to claim 2, characterized in that: The endoscope probe includes a MEMS scanning micromirror, a focusing lens, a rod lens group, an objective lens group, a light-transmitting reflective mirror and an ultrasonic transducer arranged in an endoscope housing; the MEMS scanning micromirror is used to quickly modulate and switch the light beam emitted by the half-wave plate to adjust the light beam path and intensity; the focusing lens is used to focus the light beam output by the MEMS scanning micromirror, and the optical parameters of the focusing lens are determined based on the characteristics of the sample; the rod lens group is used to adjust the propagation direction and shape of the light beam output by the focusing lens; the objective lens group is used to perform secondary focusing on the light beam output by the rod lens group; the light-transmitting reflective mirror is used to transmit the light beam output by the objective lens group to the sample and receive the photoacoustic signal fed back by the sample; the ultrasonic transducer is used to convert the photoacoustic signal into an electrical signal.

4. The photoacoustic endoscopic imaging system based on polarized light multi-angle rotation scanning according to claim 3, characterized in that: The focusing lens is an aspherical lens, the rod lens group includes a number of rod lenses that are equidistantly arranged and multi-layer coated, the objective lens group includes a number of multi-layer coated objective lenses with anti-reflective coatings, and the endoscope shell is a double-layer structure, the inner layer is a flexible material, and the outer layer is a rigid structure.

5. The photoacoustic endoscopic imaging system based on polarized light multi-angle rotation scanning according to claim 2, characterized in that: The light source system comprises a 1200 nm pulse laser and a linear polarizer. The 1200 nm pulse laser is used to generate a pulse laser beam with a wavelength of 1200 nm in response to a sequential pulse signal, and the linear polarizer is used to convert the pulse laser beam into linearly polarized light.

6. The photoacoustic endoscopic imaging system based on polarized light multi-angle rotation scanning according to any one of claims 1 to 5, characterized in that: The data reconstruction system is also used to analyze the sample image and quantify the optical properties of the sample in different directions. The control system is also used to adjust the timing pulse signal according to the optical properties so as to adjust the parameters of the pulsed laser beam.

7. The photoacoustic endoscopic imaging system based on polarized light multi-angle rotation scanning according to any one of claims 1 to 5, characterized in that: The sample is arranged in a sample pool, and the sample pool is used to provide a dynamic environment for the sample through the flow of fluid medium or gas medium. The sample pool is also provided with a temperature detection unit and a pressure detection unit, which are used to provide different experimental environments for the sample according to the respective detection data of the temperature detection unit and the pressure detection unit.

8. The photoacoustic endoscopic imaging system based on polarized light multi-angle rotation scanning according to any one of claims 1 to 5, characterized in that: The endoscopic probe, the data acquisition system and the data reconstruction system are connected by a high-speed data transmission interface.

9. The photoacoustic endoscopic imaging system based on polarized light multi-angle rotation scanning according to any one of claims 1 to 5, characterized in that: The input end of the data acquisition system is also connected to a signal amplifier and a shock-absorbing bracket for fixing the signal amplifier. The signal amplifier is used to enhance the electrical signal and output it to the data acquisition system.

10. A method for photoacoustic endoscopic imaging based on multi-angle rotational scanning of polarized light, implemented based on the photoacoustic endoscopic imaging system based on multi-angle rotational scanning of polarized light according to any one of claims 1 to 9, comprising: In response to the timing pulse signal, a pulsed laser beam of a preset wavelength is generated, and the pulsed laser beam is converted into linearly polarized light and emitted; adjusting the polarization direction of the linearly polarized light by means of a half-wave plate switched between a plurality of preset angles; Processing the light beam emitted by the half-wave plate, transmitting the processed light beam to the sample, receiving the photoacoustic signal fed back by the sample and converting it into an electrical signal; In response to the timing pulse signal, the electrical signal is collected and processed and analyzed to generate a sample image.

Images