A photoacoustic-white light common field endoscope device and imaging method with optical path multiplexing

Abstract

The present invention discloses a photoacoustic-white light common field endoscope device with optical path multiplexing and an imaging method. The device includes a handheld endoscope probe, a laser / optical illumination system, and a control and data acquisition reconstruction system; the handheld endoscope probe includes a photoacoustic-white light optical path multiplexing component, a laser coupling scanning component, and a photoacoustic white light detection component; the laser coupling scanning component realizes the focusing and scanning of the laser, and the photoacoustic-white light optical path multiplexing component generates a photoacoustic signal and a white light reflection signal; the photoacoustic signal is received by the photoacoustic detection component, and the white light emission signal is received by the white light detection component. The photoacoustic excitation optical path and the white light imaging optical path of the present invention share the same path, so that the photoacoustic imaging and the white light imaging realize common field imaging with the imaging center coincident. Therefore, the present invention can simultaneously obtain the optical imaging of the surface light reflection information and the photoacoustic imaging of the deep light absorption information, and realize the dual-modal common field imaging detection of white light guided-photoacoustic microscopy.

Description

Technical Field

[0001] The present invention belongs to the technical field of endoscope nondestructive testing, and in particular relates to a photoacoustic-white light common field endoscope device with optical path multiplexing and an imaging method. Background Art

[0002] White light imaging technology is an imaging technology that uses white light illumination and then receives white light images through a camera unit. It is an imaging technology that images the surface of the imaging area. White light hard endoscopes are currently conventional instruments widely used in industrial flaw detection, medical imaging and other fields. However, since the basic principle is to use reflected signals to obtain detection images, they are greatly affected by medium scattering and can only image the shallow surface of the imaging area.

[0003] Photoacoustic imaging technology refers to the generation of ultrasonic signals in the light absorption area of ​​biological tissues when a pulsed laser is irradiated into biological tissues. This ultrasonic signal generated by light excitation is called a photoacoustic signal. The photoacoustic signal generated by the rapid heating and expansion of the light absorbing medium in biological tissues carries the light absorption characteristic information of the tissues. By detecting the photoacoustic signal, the light absorption distribution image in the tissues can be reconstructed. Photoacoustic imaging has the advantages of both the high specificity of pure optical tissue imaging and the deep penetration characteristics of ultrasonic imaging. It reflects the difference in light absorption of the absorber. The photoacoustic endoscope developed based on photoacoustic imaging can penetrate tissues to a depth of several millimeters.

[0004] In recent years, many teams at home and abroad have proposed many solutions for photoacoustic endoscopes. Patent No. 201210186582.8 proposed a forward-looking photoacoustic endoscope, which is mainly used for endoscopic imaging of the end face of the target tissue. However, since the probe contains a piezoelectric scanning device, it is impossible to achieve a miniaturized design, and the vibration caused by the operation of the piezoelectric scanning device will generate a large noise, which is not conducive to imaging; Application No. 201711122120.9 proposed a photoacoustic endoscopic microscopic imaging device based on a MEMS mirror and an imaging method thereof. In order to obtain a sufficient imaging range, the endoscope must shorten the working distance or expand the diameter of the endoscope, which makes it difficult to achieve scanning imaging of internal organs or more hidden areas of the human body. ; At the same time, this is a single-mode imaging method. In the application scenario of photoacoustic endoscope, this endoscope has the problem that it is impossible to observe the positional relationship between the laser and the imaging area in the cavity in real time, and the laser is difficult to accurately irradiate the target imaging area; Patent No. 201310739425.X proposes an intrarectal optical, photoacoustic, and ultrasonic multi-mode imaging endoscope and its imaging method. This solution equips the optical camera in a sleeve with a diameter of 12 mm, which is large in size. At the same time, this solution cannot achieve common field imaging with overlapping imaging centers of photoacoustic imaging and white light imaging, and it is still difficult to accurately locate the imaging area; At the same time, there is also the problem that the relationship between the laser focus and the imaging area is difficult to determine, resulting in reduced resolution. Summary of the invention

[0005] The main purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art, and to provide a photoacoustic-white light common field endoscope device and imaging method with optical path multiplexing, which is the first time that the photoacoustic-white light multiplexing optical path is applied to the field of photoacoustic endoscopy, and realizes common field imaging in which the imaging centers of photoacoustic imaging and white light imaging coincide, thereby solving the problems of large size, short working distance, and unassisted positioning of the existing photoacoustic endoscopy probe.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] On one hand, the present invention provides a photoacoustic-white light common field endoscope device with optical path multiplexing, including a control and data acquisition and reconstruction system, a laser / optical illumination system, and a handheld endoscope probe; the handheld endoscope probe includes a probe housing, a photoacoustic-white light optical path multiplexing component, a laser coupling scanning component, and a photoacoustic white light detection component;

[0008] The control and data acquisition and reconstruction system controls the laser / optical illumination system to couple the emitted laser with white light and enter the handheld endoscope probe; the laser coupling scanning component realizes the focusing and scanning of the laser; the relay lens group in the photoacoustic-white light optical path multiplexing component transmits the scanning laser to the imaging area in proportion to generate a photoacoustic signal, and the illumination optical fiber in the photoacoustic-white light optical path multiplexing component simultaneously irradiates the same imaging area to generate a white light reflection signal; the generated photoacoustic signal is received by the photoacoustic white light detection component, and the white light emission signal is received by the photoacoustic white light detection component, and finally the data reconstruction and storage are realized through the control and data acquisition and reconstruction system to complete the dual-modal common field imaging;

[0009] The control and data acquisition and reconstruction system includes a computer, an FPGA and an acquisition card. The computer is first connected to the FPGA through a coaxial line to control the FPGA switch, and is connected to the acquisition card through a standard interface of the computer motherboard; the FPGA is connected to the laser coupling scanning component, the laser / optical lighting system, and the acquisition card in the handheld endoscope probe through a control signal line to synchronously control the galvanometer in the laser coupling scanning component to start scanning, the pulse laser in the laser / optical lighting system emits pulsed laser and the white light source emits white light, and the acquisition card starts acquisition synchronously;

[0010] The laser / optical illumination system comprises a pulsed laser, a white light source, a fiber coupler, a laser fiber and a light guide; one end of the laser fiber is connected to the fiber coupler via a standard fiber connector, the fiber coupler couples the laser output spatial light into the fiber, and the other end of the laser fiber is connected to the endoscope probe via a fiber interface; one end of the light guide is connected to the white light source coupler via a standard light guide interface, and the other end is connected to the endoscope probe via the light guide.

[0011] As a preferred technical solution, the probe housing in the handheld endoscope probe is provided with an optical fiber interface, a light guide interface and a camera device interface; the optical fiber interface is used to fix the optical fiber, and the other end of the optical fiber is connected to the laser / optical lighting system for transmitting pulsed laser; the light guide interface is used to fix the light guide, and the other end of the light guide is connected to the laser / optical lighting system for transmitting white light illumination; the camera device interface is used to fix the white light image receiving device in the photoacoustic / white light detection component.

[0012] As a preferred technical solution, the laser coupling scanning component is arranged at the rear end of the optical fiber interface, connected through a signal line control and data acquisition and reconstruction system, and is used to shape and focus the optical fiber output laser and drive the scanning; a photoacoustic / white light optical path multiplexing component is arranged thereafter, and a photoacoustic signal receiving device in the photoacoustic / white light detection component is provided at the end of the photoacoustic / white light optical path multiplexing component, which is used to receive the photoacoustic signal generated by the sample when excited by the pulsed laser.

[0013] As a preferred technical solution, the laser coupling scanning component in the endoscopic probe includes a laser focusing optical path, a reflector and a galvanometer. The laser focusing optical path is arranged behind the optical fiber interface, and the reflector and the galvanometer are fixed after the laser focusing optical path. The three cooperate with each other to realize the two-dimensional scanning of the laser in the plane before the photoacoustic-white light multiplexing optical path; wherein, the focal plane of the photoacoustic scanning laser and the focal plane of the white light overlap before the multiplexing optical path.

[0014] As a preferred technical solution, the photoacoustic / white light optical path multiplexing component in the endoscopic probe includes a photoacoustic-white light multiplexing optical path and an illumination optical fiber, the photoacoustic-white light multiplexing optical path includes a spectroscope and an optical path relay system, wherein the spectroscope is fixed at the rear end of the laser scanning optical path, and is used to reflect laser light and transmit white light; the optical path relay system is fixed at the rear end of the spectroscope, and the optical path relay system is composed of one or more light transmission groups, and the light transmission group is symmetrically combined by two identical rod lenses; the illumination optical fiber is wrapped around the optical path relay system, and is used to transmit the illumination white light coupled into the endoscope from the light guide interface to the imaging area; the photoacoustic-white light multiplexing optical path is used to simultaneously realize the proportional transmission of scanning laser in photoacoustic imaging and the proportional transmission of white light images in white light imaging, and the photoacoustic excitation optical path and the white light imaging optical path share the same path, so that the photoacoustic imaging and the white light imaging realize common field imaging with the imaging center overlapping.

[0015] As a preferred technical solution, the rod lens is composed of two negative lenses and a biconvex lens.

[0016] As a preferred technical solution, the rod lens is a Green lens with a long working distance.

[0017] As a preferred technical solution, the photoacoustic / white light detection component in the endoscopic probe includes a white light image receiving device and a photoacoustic signal receiving device; wherein the white light image receiving device includes a photographic unit and an eyepiece group; the camera unit is fixed on the camera device interface, and the eyepiece group is arranged between the beam splitter and the camera unit in the photoacoustic-white light multiplexing optical path.

[0018] As a preferred technical solution, the eyepiece group includes a double plano-convex lens for focusing white light, and the photoacoustic signal receiving device includes a light-transmitting reflective plate and an ultrasonic transducer. The light-transmitting reflective plate is used to reflect the laser-excited photoacoustic signal, and its main frequency is 2 to 50 MHz.

[0019] Another aspect of the present invention provides an imaging method of a photoacoustic-white light common field endoscope device with optical path multiplexing, comprising the following steps:

[0020] The computer controls the operation of the FPGA, which controls the white light source to emit white light and couple it into the handheld endoscope probe. The white light is transmitted to the front end of the probe through the illumination optical fiber to illuminate the imaging area. After the white light is reflected by the imaging area, it is transmitted to the white light image receiving device through the photoacoustic-white light optical path multiplexing component to be collected. The collected signal is transmitted to the computer after analog-to-digital conversion, and the computer reconstructs and displays it on the monitor to achieve real-time white light imaging.

[0021] During white light imaging, the FPGA drives the pulse laser system to emit laser light, and the laser light is introduced into the optical fiber by the fiber coupler after being shaped by the optical path. After being emitted from the optical fiber, the laser light is focused by the laser focusing optical path and reflected by the reflector to the galvanometer. The control and data acquisition and reconstruction system controls the deflection of the galvanometer to drive the focused laser to scan in front of the multiplexed optical path. The photoacoustic-white light optical path multiplexing component transmits the scanning laser to the target area in proportion and stimulates the photoacoustic signal. The photoacoustic signal generated by the deep layer of the target area is reflected by the light-transmitting reflective sheet and collected after reaching the working surface of the ultrasonic transducer. The collected signal is transmitted to the computer after analog-to-digital conversion, and the computer reconstructs and displays it on the monitor to achieve photoacoustic imaging.

[0022] After the dual-modality imaging is completed, the computer will store the original data of the photoacoustic image information and the white light image information and the reconstructed image.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0024] 1. The present invention uses white light imaging to guide photoacoustic imaging, and realizes the transmission of scanning laser in proportion in photoacoustic imaging and the transmission of white light image in proportion in white light imaging at the same time. The photoacoustic excitation optical path and the white light imaging optical path share the same path, so that photoacoustic imaging and white light imaging realize common field imaging with overlapping imaging centers; it solves the problem that in the application scenario of photoacoustic endoscope, the endoscope cannot observe the positional relationship between the laser and the imaging area in the cavity in real time, and the laser is difficult to accurately irradiate the target imaging area;

[0025] 2. The working photoacoustic-white light multiplexed optical path of the probe of the present invention is applied to the field of photoacoustic endoscopy, which can extend the working distance (greater than 20 cm) and reduce the diameter of the multiplexed optical path probe for the first time, greatly expanding the application scenarios of the photoacoustic endoscope, and enabling the photoacoustic endoscope to realize scanning and imaging of internal organs and / or relatively hidden areas of the human body.

[0026] 3. The images formed by the probe of the present invention include photoacoustic images, white light images, and photoacoustic-white light coincident images of the same position, as well as three-dimensional images of the imaging area in the depth direction, which can be widely used in industrial flaw detection, medical imaging and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 A schematic diagram of a photoacoustic-white light common field endoscope device with optical path multiplexing in an embodiment;

[0029] Figure 2 It is a schematic diagram of the structure of an endoscope probe of a photoacoustic-white light common field endoscope device with optical path multiplexing in an embodiment;

[0030] Figure 3 A schematic diagram of the optical path of an endoscope probe of a photoacoustic-white light common field endoscope device with optical path multiplexing in an embodiment;

[0031] Figure 4 This is a photoacoustic-white light common field white light imaging diagram of an endoscope probe of a photoacoustic-white light common field endoscope device with optical path multiplexing in an embodiment;

[0032] Figure 5 This is a photoacoustic-white light common field photoacoustic imaging diagram of an endoscope probe of a photoacoustic-white light common field of view endoscope device with optical path multiplexing in an embodiment.

[0033] Explanation of the accompanying numbers: 1-control and data acquisition and reconstruction system; 2-laser / optical illumination system; 3-handheld endoscope probe; 4-photoacoustic-white light path multiplexing component; 5-laser coupling scanning component; 6-photoacoustic-white light detection component; 7-laser optical fiber; 8-illumination optical fiber; 9-optical fiber interface; 10-light guide interface; 11-camera device interface; 12-laser focusing optical path; 13-reflector; 14-MEMS galvanometer; 15-beam splitter; 16-rod lens; 17-camera unit; 18-eyepiece group; 19-anti-sound glass sheet; 20-ultrasonic transducer; 21-probe housing. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.

[0035] like Figure 1 As shown, the present embodiment provides a photoacoustic-white light common field endoscope device with optical path multiplexing, including a control and data acquisition and reconstruction system 1, a laser / optical illumination system 2 and a handheld endoscope probe 3, wherein the control and data acquisition and reconstruction system 1 is connected to the laser / optical illumination system 2 and the handheld endoscope probe 3 respectively, and the laser / optical illumination system 2 is also connected to the handheld endoscope probe 3; the control and data acquisition and reconstruction system 1 controls the laser / optical illumination system 2 to couple the emitted laser and white light into the handheld endoscope probe 3; the laser coupling scanning component 5 realizes the focusing and scanning of the laser; the relay lens group in the photoacoustic-white light optical path multiplexing component 4 transmits the scanning laser to the imaging area in proportion to generate a photoacoustic signal, and the illumination optical fiber 8 in the optical path multiplexing component simultaneously irradiates the same imaging area to generate a white light reflection signal; the generated photoacoustic signal is received by the photoacoustic detection component, and the white light emission signal is received by the white light detection component, and finally the data reconstruction and storage are realized through the control and data acquisition and reconstruction system 1 to complete the dual-modal common field imaging.

[0036] In the technical solution of this embodiment, the photoacoustic excitation optical path and the white light imaging optical path share the same path, so that the photoacoustic imaging and the white light imaging achieve common-field imaging with the imaging centers overlapping. Therefore, the present invention can simultaneously obtain optical imaging of surface light reflection information and photoacoustic imaging of deep light absorption information, and realize dual-modal common-field imaging detection of white light guidance-photoacoustic microscopy, which can be applied to industrial flaw detection, medical imaging and other fields.

[0037] Furthermore, the control and data acquisition and reconstruction system 1 includes a computer, an FPGA and an acquisition card. The computer is first connected to the FPGA through a coaxial line to control the FPGA switch; and the computer is connected to the acquisition card through a standard interface of the computer motherboard; the FPGA is connected to the laser coupling scanning component 5, the laser / optical illumination system 2, and the acquisition card in the handheld endoscopic probe 3 through a control signal line to synchronously control the MEMS galvanometer 14 in the laser coupling scanning component to start scanning, the pulse laser in the laser / optical illumination system 2 to emit pulsed laser and the white light source to emit white light, and the acquisition card starts acquisition synchronously.

[0038] Furthermore, in this embodiment, only one FPGA is used to realize the functions of the present invention, which reduces the size of the device, reduces the cost of the device and provides stability. When it is necessary to upgrade, it can be realized by modifying the program in the FPGA. The FPGA in this embodiment is used as a controller to mainly complete the collection, caching and filtering of data. In the collected photoacoustic data, there will inevitably be random noise and signals outside the acquisition bandwidth, so it is necessary to filter the collected signals. The essence of the filter is to perform multiplication and accumulation operations on the collected sequence. For addition operations, FPGA can achieve real-time operations, and most of the current FPGAs have dedicated multipliers inside, which can also achieve the purpose of real-time imaging for multiplication operations. Therefore, it is very convenient and fast to implement the filter inside the FPGA. In this way, it is unnecessary to filter the photoacoustic data on the computer, and the software operations on the computer are all executed sequentially, which is relatively slow compared to the FPGA. Therefore, filtering the photoacoustic signal on the FPGA will greatly shorten the imaging time.

[0039] Furthermore, the laser / optical illumination system 2 includes a 532nm wavelength pulse laser, a white light source, a fiber coupler, a laser fiber 7 and a light guide; the laser fiber adopts a 4μm single-mode fiber, one end of the 4μm single-mode fiber is connected to the fiber coupler through a standard fiber connector, the fiber coupler couples the 532nm wavelength pulse light emitted by the laser into the 4μm single-mode fiber, and the other end of the 4μm single-mode fiber is connected to the endoscope probe through the fiber interface 9; one end of the light guide is connected to the white light source coupler through the standard light guide interface 10, and the other end is connected to the endoscope probe through the light guide.

[0040] like Figure 2 , 3As shown, the handheld endoscope probe 3 includes a probe housing 21, a laser coupling scanning component, a photoacoustic / white light optical path multiplexing component and a photoacoustic / white light detection component 6; wherein the probe housing 21 is provided with an optical fiber interface 9, a light guide interface 10 and a camera interface 11; the optical fiber interface 9 is used to fix the optical fiber, and the other end of the optical fiber is connected to the laser / optical lighting system 2 for transmitting pulsed laser; the light guide interface 10 is used to fix the light guide, and the other end of the light guide is connected to the laser / optical lighting system 2 for transmitting illuminating white light; the camera device interface is an optical C-type interface for fixing the white light image receiving device in the photoacoustic / white light detection component 6; the photoacoustic coupling scanning is arranged at the rear end of the optical fiber interface 9, and is connected to the data acquisition and reconstruction system 1 through a signal line control, and is used to shape and focus the optical fiber output laser and drive the scanning; a photoacoustic / white light optical path multiplexing component is then arranged, and a photoacoustic signal receiving device in the photoacoustic / white light detection component 6 is arranged at the end of the component for receiving the photoacoustic signal generated by the sample being excited by the pulsed laser.

[0041] Furthermore, the laser coupling scanning component in the endoscope probe includes a laser focusing optical path 12, a reflector 13, and a MEMS galvanometer 14, wherein the laser focusing optical path 12 is arranged behind the optical fiber interface 9, and the reflector 13 and the MEMS galvanometer 14 are fixed behind the laser focusing optical path 12, and the three cooperate with each other to realize the two-dimensional scanning of the plane of the laser before the photoacoustic-white light multiplexing optical path. Among them, the focal plane of the photoacoustic scanning laser and the focal plane of the white light overlap before the multiplexing optical path.

[0042] Furthermore, the photoacoustic / white light optical path multiplexing component in the endoscope probe includes a photoacoustic-white light multiplexing optical path and an illumination optical fiber 8, wherein the photoacoustic-white light multiplexing optical path includes a 50:50 beam splitter 15 and an optical path relay system, wherein the beam splitter 15 is fixed at the rear end of the laser scanning optical path for reflecting laser light and transmitting white light; the optical path relay system is fixed at the rear end of the beam splitter 15, and the optical path relay system is composed of one or more light transmission groups, and the light transmission group is symmetrically composed of two identical rod lenses 16; the rod lens 16 is composed of two negative lenses and a double The convex lens is composed of a convex lens or a Green lens with a long working distance, and its diameter is 2.8mm and its length is 24mm; the illumination optical fiber 8 is wrapped around the optical path relay system to transmit the illumination white light coupled into the endoscope from the light guide interface 10 to the imaging area; the photoacoustic-white light multiplexing optical path is used to simultaneously realize the proportional transmission of scanning laser in photoacoustic imaging and the proportional transmission of white light image in white light imaging, and the photoacoustic excitation optical path and the white light imaging optical path share the same path, so that the photoacoustic imaging and the white light imaging realize common field imaging with the imaging center coincident;

[0043] Further, the photoacoustic / white light detection component 6 in the endoscope probe includes a white light image receiving device and a photoacoustic signal receiving device; wherein the white light image receiving device includes a camera unit 17 and an eyepiece group 18; the camera unit 17 is fixed on the camera device interface, and the eyepiece group 18 is arranged between the beam splitter 15 and the camera unit 17 in the photoacoustic-white light multiplexing optical path; the eyepiece group 18 includes a double plano-convex lens for focusing white light, and the photoacoustic signal receiving device includes a light-transmitting and anti-sound glass sheet 19 and an ultrasonic transducer 20, and the light-transmitting and anti-sound glass sheet is used to reflect the photoacoustic signal excited by the laser, and its main frequency is 30MHz;

[0044] Another embodiment of the present application also discloses an imaging method of a photoacoustic-white light common field endoscope device with optical path multiplexing, using this method, photoacoustic-white light common field simultaneous imaging, including white light imaging, photoacoustic common field excitation imaging, dual-mode photoacoustic-white light data three-dimensional reconstruction and display, the specific method is:

[0045] (1) The computer controls the operation of the FPGA. The FPGA controls the white light source to emit white light coupled into the handheld endoscope probe 3. The white light is transmitted to the front end of the probe through the illumination optical fiber 8 to illuminate the imaging area. After the white light is reflected by the imaging area, it is transmitted to the white light image receiving device through the photoacoustic-white light multiplexing optical path to be collected. The collected signal is transmitted to the computer after analog-to-digital conversion. The computer reconstructs and displays it on the display, realizing real-time white light imaging. Figure 4 As shown;

[0046] (2) During white light imaging, the FPGA drives the pulse laser system to emit laser light. After the laser light is shaped through the optical path, it is introduced into the optical fiber by the optical fiber coupler. After the laser light is emitted from the optical fiber, it is focused through the laser focusing optical path 12 and reflected by the reflector 13 to the MEMS galvanometer 14. The control and data acquisition and reconstruction system 1 controls the deflection of the MEMS galvanometer 14 to drive the focused laser light to scan in front of the multiplexed optical path. The multiplexed optical path transmits the scanning laser light to the target area in proportion and stimulates the photoacoustic signal. The photoacoustic signal generated by the deep layer of the target area is reflected by the light-transmitting reflective sheet and reaches the working surface of the ultrasonic transducer 20 to be collected. The collected signal is transmitted to the computer after analog-to-digital conversion. The computer reconstructs and displays it on the display to achieve photoacoustic imaging.

[0047] (3) After the dual-modality imaging is completed, the computer stores the original data of the photoacoustic image information and the white light image information and the reconstructed image, such as Figure 5 shown.

[0048] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0049] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A photoacoustic-white light common field endoscope device with optical path multiplexing, characterized in that: The invention comprises a control and data acquisition reconstruction system, a laser / optical illumination system and a handheld endoscope probe; the handheld endoscope probe comprises a probe housing, a photoacoustic-white light optical path multiplexing component, a laser coupling scanning component and a photoacoustic white light detection component; the probe housing in the handheld endoscope probe is provided with an optical fiber interface, a light guide interface and a camera interface; the optical fiber interface is used to fix the optical fiber, and the other end of the optical fiber is connected to the laser / optical illumination system for transmitting pulsed laser; the light guide interface is used to fix the light guide, and the other end of the light guide is connected to the laser / optical illumination system for transmitting white light illumination; the camera interface is used to fix the white light image receiving device in the photoacoustic / white light detection component; the photoacoustic / white light optical path multiplexing component in the endoscope probe comprises a photoacoustic-white light Multiplexing optical path and illumination optical fiber, the photoacoustic-white light multiplexing optical path includes a beam splitter and an optical path relay system, wherein the beam splitter is fixed at the rear end of the laser scanning optical path, and is used to reflect laser light and transmit white light; the optical path relay system is fixed at the rear end of the beam splitter, and the optical path relay system is composed of one or more light transmission groups, and the light transmission group is symmetrically combined by two identical rod lenses; the illumination optical fiber is wrapped around the optical path relay system, and is used to transmit the illumination white light coupled into the endoscope from the light guide interface to the imaging area; the photoacoustic-white light multiplexing optical path is used to simultaneously realize the transmission of scanning laser in a moderate proportion in photoacoustic imaging and the transmission of white light images in a moderate proportion in white light imaging, and the photoacoustic excitation optical path and the white light imaging optical path share the same path, so that the photoacoustic imaging and the white light imaging realize common field imaging with the imaging center overlapping; The control and data acquisition and reconstruction system controls the laser / optical illumination system to couple the emitted laser with white light and enter the handheld endoscope probe; the laser coupling scanning component realizes the focusing and scanning of the laser; the relay lens group in the photoacoustic-white light optical path multiplexing component transmits the scanning laser to the imaging area in proportion to generate a photoacoustic signal, and the illumination optical fiber in the photoacoustic-white light optical path multiplexing component simultaneously irradiates the same imaging area to generate a white light reflection signal; the generated photoacoustic signal is received by the photoacoustic white light detection component, and the white light emission signal is received by the photoacoustic white light detection component, and finally the data reconstruction and storage are realized through the control and data acquisition and reconstruction system to complete the dual-modal common field imaging; The control and data acquisition and reconstruction system includes a computer, an FPGA and an acquisition card. The computer is first connected to the FPGA through a coaxial line to control the FPGA switch, and is connected to the acquisition card through a standard interface of the computer motherboard; the FPGA is connected to the laser coupling scanning component, the laser / optical lighting system, and the acquisition card in the handheld endoscope probe through a control signal line to synchronously control the galvanometer in the laser coupling scanning component to start scanning, the pulse laser in the laser / optical lighting system emits pulsed laser and the white light source emits white light, and the acquisition card starts acquisition synchronously; The laser / optical illumination system comprises a pulsed laser, a white light source, a fiber coupler, a laser fiber and a light guide; one end of the laser fiber is connected to the fiber coupler via a standard fiber connector, the fiber coupler couples the laser output spatial light into the fiber, and the other end of the laser fiber is connected to the endoscope probe via a fiber interface; one end of the light guide is connected to the white light source coupler via a standard light guide interface, and the other end is connected to the endoscope probe via the light guide.

2. The photoacoustic-white light common field endoscope device with optical path multiplexing according to claim 1 is characterized in that: The laser coupling scanning component is arranged at the rear end of the optical fiber interface, and is connected to the data acquisition and reconstruction system through a signal line control, and is used to shape and focus the optical fiber output laser and drive the scanning; a photoacoustic / white light optical path multiplexing component is arranged thereafter, and a photoacoustic signal receiving device in the photoacoustic / white light detection component is arranged at the end of the photoacoustic / white light optical path multiplexing component, which is used to receive the photoacoustic signal generated by the sample when it is excited by the pulsed laser.

3. The photoacoustic-white light common field endoscope device with optical path multiplexing according to claim 1, characterized in that: The laser coupling scanning component in the endoscope probe includes a laser focusing optical path, a reflector and a galvanometer. The laser focusing optical path is arranged behind the optical fiber interface. The reflector and the galvanometer are fixed after the laser focusing optical path. The three cooperate with each other to realize the planar two-dimensional scanning of the laser in front of the photoacoustic-white light multiplexing optical path; wherein the photoacoustic scanning laser focal plane and the white light focal plane overlap in front of the multiplexing optical path.

4. The photoacoustic-white light common field endoscope device with optical path multiplexing according to claim 1, characterized in that: The rod lens is composed of two negative lenses and a biconvex lens.

5. The photoacoustic-white light common field endoscope device with optical path multiplexing according to claim 1, characterized in that: The rod lens is a Green lens with a long working distance.

6. The photoacoustic-white light common field endoscope device with optical path multiplexing according to claim 1, characterized in that: The photoacoustic / white light detection component in the endoscopic probe includes a white light image receiving device and a photoacoustic signal receiving device; wherein the white light image receiving device includes a photographic unit and an eyepiece group; the photographic unit is fixed on the interface of the camera device, and the eyepiece group is arranged between the spectroscope and the camera unit in the photoacoustic-white light multiplexing optical path.

7. The photoacoustic-white light common field endoscope device with optical path multiplexing according to claim 6, characterized in that: The eyepiece group includes a double plano-convex lens for focusing white light. The photoacoustic signal receiving device includes a light-transmitting reflective plate and an ultrasonic transducer. The light-transmitting reflective plate is used to reflect the photoacoustic signal excited by the laser, and its main frequency is 2-50 MHz.

8. An imaging method of a photoacoustic-white light common field endoscope device based on the optical path multiplexing of any one of claims 1 to 7, characterized in that: The steps include: The computer controls the operation of the FPGA, which controls the white light source to emit white light and couple it into the handheld endoscope probe. The white light is transmitted to the front end of the probe through the illumination optical fiber to illuminate the imaging area. After the white light is reflected by the imaging area, it is transmitted to the white light image receiving device through the photoacoustic-white light optical path multiplexing component to be collected. The collected signal is transmitted to the computer after analog-to-digital conversion, and the computer reconstructs and displays it on the monitor to achieve real-time white light imaging. During white light imaging, the FPGA drives the pulse laser system to emit laser light, and the laser light is introduced into the optical fiber by the fiber coupler after being shaped by the optical path. After being emitted from the optical fiber, the laser light is focused by the laser focusing optical path and reflected by the reflector to the galvanometer. The control and data acquisition and reconstruction system controls the deflection of the galvanometer to drive the focused laser to scan in front of the multiplexed optical path. The photoacoustic-white light optical path multiplexing component transmits the scanning laser to the target area in proportion and stimulates the photoacoustic signal. The photoacoustic signal generated by the deep layer of the target area is reflected by the light-transmitting reflective sheet and collected after reaching the working surface of the ultrasonic transducer. The collected signal is transmitted to the computer after analog-to-digital conversion, and the computer reconstructs and displays it on the monitor to achieve photoacoustic imaging. After the dual-modality imaging is completed, the computer will store the original data of the photoacoustic image information and the white light image information and the reconstructed image.

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