Transparent opto-acoustic multi-mode imaging array probe, manufacturing method thereof and imaging system
By integrating a transparent PMN-PT ultrasonic array transducer and an optical imaging unit into the photoacoustic probe, the problems of near-field blind zone and low efficiency of single array element in the photoacoustic probe are solved, realizing multimodal composite of photoacoustic, ultrasonic and optical imaging, and improving imaging sensitivity and efficiency.
Patent Information
- Application Number
- CN202410594425.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-14
- Publication Date
- 2025-11-14
AI Technical Summary
Existing photoacoustic probe structures result in near-field blind spots in photoacoustic imaging, and transparent photoacoustic array probes are mainly single-element, which cannot efficiently achieve multimodal imaging, especially integrated optical imaging.
A transparent PMN-PT ultrasonic array transducer is used, combined with a transparent backing layer, a matching layer and a conductive film, to integrate photoacoustic, ultrasonic and optical imaging units, and achieve synchronous imaging of the three through optical fiber and a dichroic mirror.
It achieves multimodal composite imaging of photoacoustic, ultrasonic, and optical imaging, avoids near-field blind spots, improves imaging sensitivity and efficiency, and expands application scenarios.
Smart Images
Figure CN120938337A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of photoacoustic imaging technology, specifically relating to a transparent photoacoustic multimodal imaging array probe, a method for manufacturing the transparent photoacoustic multimodal imaging array probe, and a transparent photoacoustic multimodal imaging system. Background Technology
[0002] Ultrasound imaging and optical imaging are currently important imaging tools for clinical diagnosis of various diseases and scientific experiments, with wide applications. Photoacoustic imaging, which combines the advantages of both, is a novel non-invasive biomedical imaging method that has emerged in recent years. When a short-pulse laser irradiates biological tissue, the tissue absorbs the light, causing thermal expansion and contraction, which generates ultrasound signals. Collecting and processing these signals yields the corresponding photoacoustic images. Photoacoustic imaging combines the high selectivity of pure optical tissue imaging with the deep penetration of pure ultrasound tissue imaging, providing high-resolution and high-contrast functional tissue images. It also avoids the influence of light scattering in principle, breaking through the depth limitations of high-resolution optical imaging and showing excellent application prospects.
[0003] However, since photoacoustic signals are essentially ultrasonic signals, the primary detector used in photoacoustic imaging is currently the ultrasonic probe. This probe utilizes the piezoelectric effect to convert the photoacoustic signal into an electrical signal, which is then processed by the system for imaging. Therefore, existing research and products combine photoacoustic and ultrasonic imaging to achieve dual-modal imaging, such as Visualsonics' Vevo-LAZR system. However, due to probe limitations, it cannot achieve purely optical imaging, nor can it be extended to optical coherence or fluorescence imaging. In short, existing photoacoustic probes primarily use a side-mounted design, with the ultrasonic probe in the middle and laser light illuminating both sides of the probe via optical fiber. Commercial products may also enclose both probes within the same housing, but the basic structure remains the same. This method results in a blind spot / shadow in the near-field of the probe due to the lack of laser illumination, and the laser energy cannot be fully concentrated within the probe's detection area.
[0004] To overcome the shortcomings of side-mounted photoacoustic probes, researchers have used transparent piezoelectric materials such as lithium niobate to create transparent ultrasonic probes and direct-firing photoacoustic probes. These probes can concentrate laser energy onto the detection area of the ultrasonic probe, avoiding near-field blind zones and improving the intensity of photoacoustic signals. However, most current transparent photoacoustic array probes use lithium niobate, which has limited piezoelectric properties, affecting the detection sensitivity and performance of photoacoustic and ultrasonic imaging.
[0005] In recent years, researchers have used alternating electric fields to polarize PMN-PT crystals, eliminating ferroelectric domain walls that scatter light. This has resulted in PMN-PT piezoelectric single-crystal materials that possess high piezoelectric coefficients (greater than 2100 pC / N), high electro-optic coefficients (220 pm / V), and theoretically limiting transmittance (DOI: 10.1038 / s41586-019-1891-y10.1038 / d41586-020-00038-z). This provides a possibility for the development of transparent photoacoustic probes based on high-performance piezoelectric materials.
[0006] However, currently, transparent photoacoustic probes based on PMN-PT are mainly single-element probes, which can only perform two-dimensional or three-dimensional imaging through mechanical scanning and other methods, resulting in low efficiency. At the same time, transparent photoacoustic array probes are mainly used for photoacoustic or integrated ultrasound imaging, and there are no multimodal composite probes with integrated optics yet. Summary of the Invention
[0007] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide an improved transparent photoacoustic multimodal imaging array probe.
[0008] The invention also relates to a method for fabricating a transparent photoacoustic multimodal imaging array probe and a transparent photoacoustic multimodal imaging system.
[0009] To solve the above technical problems, the present invention adopts the following technical solution:
[0010] A transparent photoacoustic multimodal imaging array probe includes a probe body, a transducer, and a photoacoustic imaging mechanism. The transducer is a transparent PMN-PT ultrasonic array transducer, comprising a multi-element linear array or phased array transparent PMN-PT single crystal; a transparent backing layer and a transparent matching layer located on the two end surfaces of the transparent PMN-PT single crystal; and a transparent conductive film located between the transparent backing layer and the transparent PMN-PT single crystal, and between the transparent PMN-PT single crystal and the transparent matching layer. The photoacoustic imaging mechanism includes an ultrasonic imaging unit, a photoacoustic imaging unit, and an optical imaging unit that use the same transparent PMN-PT ultrasonic array transducer, wherein optical imaging, ultrasonic imaging, and photoacoustic imaging can be synchronized.
[0011] Preferably, the number of array elements in a multi-element array is ≥8, and the center frequency is ≥0.5MHz.
[0012] According to a specific embodiment and preferred aspect of the present invention, the transparent conductive film is indium tin oxide, aluminum-doped zinc oxide, fluorine-doped tin oxide, or antimony-doped tin oxide; and / or, the transparent backing layer is transparent tempered glass; and / or, the transparent matching layer is a polymer epoxy or acrylic plastic, and the thickness of the transparent matching layer is less than or equal to 1 / 4 of the wavelength of the operating frequency of the probe. In short, the surface of the transparent backing layer connected to the transparent PMN-PT single crystal is used to form an equally spaced array of transparent conductive circuits using processes such as photolithography and sputtering, and pads are formed at the ends for cable soldering or connector connection to cables, and connected to the system host via cables. Simultaneously, a transparent conductive thin film layer is also deposited as an electrode on the side connected to the transparent PMN-PT, and the thickness of the matching layer is approximately 1 / 4 of the wavelength of the probe's operating frequency.
[0013] Preferably, a transparent Parylene film is also formed on the surface of the transparent matching layer. The Parylene film (which is commercially available and is a conventional product) mainly improves the acoustic matching coupling effect.
[0014] According to another specific embodiment and preferred aspect of the present invention, the photoacoustic imaging unit includes a photoacoustic fiber and a fiber optic illumination assembly, wherein the photoacoustic fiber is used to transmit near-infrared short-pulse laser required for photoacoustic imaging; the fiber optic illumination assembly includes a beam expander and a confocal lens, and the laser is guided by the fiber and then expanded and collimated before illuminating the transparent PMN-PT ultrasonic array transducer. In some specific embodiments, the beam expander is a biconcave lens; the confocal convex lens is a convex lens. In short, the laser is guided by the fiber to illuminate the biconcave lens for beam expansion, then collimated by the confocal convex lens, and finally perpendicularly illuminates the target through the transparent array transducer, providing uniform and stable laser illumination for photoacoustic imaging.
[0015] According to another specific embodiment and preferred aspect of the present invention, the optical imaging unit includes an imaging fiber, a dichroic mirror, and a CMOS sensor. The imaging fiber is used to transmit continuous visible white light required for optical imaging, the wavelength of which is less than 800 nm. The dichroic mirror is relatively tilted and positioned above the probe body, and the angle between the dichroic mirror and the incident angle of the light beam is acute. In some specific embodiments, the angle between the dichroic mirror and the incident angle of the light beam is 45°. When a laser used for photoacoustic imaging illuminates the dichroic mirror, because its wavelength is >800 nm, the laser completely passes through the dichroic mirror without reflection. When white light of optical imaging with a wavelength of 380–750 nm illuminates the dichroic mirror, because its wavelength is <800 nm, the light illuminating the dichroic mirror undergoes total internal reflection and is entirely reflected onto the target. The light reflected back from the target is reflected by the dichroic mirror and the information is captured by the CMOS sensor for imaging.
[0016] Another technical solution of the present invention is: a method for manufacturing a transparent photoacoustic multimodal imaging array probe, which includes the following steps:
[0017] S1. Transducer fabrication
[0018] First, the transparent backing and transparent conductive circuit part are tightly bonded to the transparent PMN-PT with transparent epoxy resin. Then, the array structure is cut according to the set transducer array size using a cutting machine. Then, the transparent matching layer is bonded to the upper surface of the PMN-PT with transparent epoxy resin. The conductive layer is used to connect the cut PMN-PT arrays to form a common ground connection, and the common ground cable is connected at the edge.
[0019] S2, Probe fabrication
[0020] The transparent PMN-PT ultrasonic array transducer and photoacoustic imaging mechanism are assembled in the probe body so that the transparent PMN-PT ultrasonic array transducer can emit and receive ultrasonic waves in ultrasonic imaging mode; receive photoacoustic signals generated by the target in photoacoustic imaging mode; and serve as a transparent protective window in optical imaging mode.
[0021] Another technical solution of the present invention is: a transparent photoacoustic multimodal imaging system, comprising a transparent photoacoustic multimodal imaging array probe, a photoacoustic imaging pulsed laser, an optical imaging light source, and an ultrasonic imaging host, wherein the pulsed laser, the light source, and the host are respectively connected to the transparent photoacoustic multimodal imaging array probe via optical fiber or cable; for ultrasonic imaging, only the PMN-PT ultrasonic array probe needs to be excited separately, and the received ultrasonic echo can be imaged in conventional B-mode or C-mode; for photoacoustic imaging, the photoacoustic excitation laser needs to be turned on, and the laser pulse trigger or the host emits a trigger signal to control the laser's emission timing, and then the PMN-PT ultrasonic array probe receives the photoacoustic signal generated by the target for photoacoustic imaging; for optical imaging, the illumination light source is turned on, the light illuminating the dichroic mirror undergoes total internal reflection, and all of it illuminates the target, while the light reflected back from the target is reflected by the dichroic mirror and captured and transmitted by the CMOS sensor for optical imaging.
[0022] Preferably, the pulsed laser is an OPO short-pulse laser, mainly transmitting near-infrared short-pulse laser light required for photoacoustic imaging, such as Nd:YAG 1064nm, or tunable wavelength near-infrared pulsed laser light from an OPO laser. The light source is white light excited by sources such as LEDs or xenon lamps.
[0023] Due to the implementation of the above technical solutions, the present invention has the following advantages compared with the prior art:
[0024] Existing PMN-PT transparent photoacoustic probes are mainly single-element probes, which can only perform two-dimensional or three-dimensional imaging through mechanical scanning and other methods, resulting in low efficiency. Furthermore, transparent photoacoustic array probes are primarily used for photoacoustic or integrated ultrasonic imaging, lacking integrated optical multimodal composite probes, among other shortcomings. This invention cleverly solves these shortcomings by using a transparent photoacoustic multimodal imaging array probe with an integrated structural design. When using this transparent photoacoustic multimodal imaging array probe for ultrasonic imaging, only the PMN-PT ultrasonic array probe needs to be excited individually, and the received ultrasonic echo can be imaged in conventional B-mode or C-mode. For photoacoustic imaging, the photoacoustic excitation laser needs to be activated, and the laser's emission timing is controlled by laser pulse triggering or a trigger signal emitted by the host, thereby enabling the PMN-PT ultrasonic array to transmit the signal. The array probe receives the photoacoustic signal generated by the target and performs photoacoustic imaging. For optical imaging, the illumination source is turned on, and the light illuminating the dichroic mirror undergoes total internal reflection, illuminating the target. The light reflected back from the target is then reflected by the dichroic mirror and captured by the CMOS sensor to transmit the signal for optical imaging. Therefore, on one hand, optical imaging does not occupy the ultrasonic array probe, thus fully utilizing the advantages of the light field and ultrasonic probe, and is compatible with ultrasonic, optical, and photoacoustic imaging. That is, it can form a multimodal composite probe of optical, ultrasonic, and photoacoustic modes, which can operate synchronously, making it highly practical. On the other hand, it expands the application scenarios of the transparent photoacoustic multimodal imaging array probe, providing high-quality image information for related research and clinical applications, and expanding the application areas of transparent photoacoustic probes. Furthermore, its simple structure and rich functionality meet the needs of high-performance multimodal imaging. Attached Figure Description
[0025] Figure 1 This is a schematic diagram of the transparent photoacoustic multimodal imaging array probe of Example 1;
[0026] Figure 2 for Figure 1 Schematic diagram of a transparent PMN-PT ultrasonic array transducer;
[0027] Figure 3 for Figure 2 Schematic diagram of the optical fiber illumination assembly;
[0028] Figure 4 This is a schematic diagram of the transparent photoacoustic multimodal imaging system of Example 2;
[0029] The components include: ① Transparent photoacoustic multimodal imaging array probe; 1. Probe body; 2. Transducer; 20. Transparent PMN-PT single crystal; 21. Transparent backing layer; 22. Transparent matching layer; 23. Transparent conductive film; 24. Parylene thin film; 3. Photoacoustic imaging mechanism; 30. Ultrasonic imaging unit; 300. Cable; 31. Photoacoustic imaging unit; 310. Photoacoustic optical fiber; 311. Fiber optic projection assembly; a. Beam expander; b. Confocal lens; ② Pulsed laser; ③ Light source; ④ Main unit. Detailed Implementation
[0030] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.
[0031] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0032] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0033] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0034] In this invention, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0035] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.
[0036] Example 1
[0037] like Figures 1 to 3 As shown, the transparent photoacoustic multimodal imaging array probe of this embodiment includes a probe body 1, a transducer 2, and a photoacoustic imaging mechanism 3. The transducer 2 is a transparent PMN-PT ultrasonic array transducer, and includes a multi-element linear array or phased array transparent PMN-PT single crystal 20; a transparent backing layer 21 and a transparent matching layer 22 located on the two end surfaces of the transparent PMN-PT single crystal 20; and a transparent conductive film 23 located between the transparent backing layer 21 and the transparent PMN-PT single crystal 20, and between the transparent PMN-PT single crystal 20 and the transparent matching layer 22. The photoacoustic imaging mechanism 3 includes an ultrasonic imaging unit 30, a photoacoustic imaging unit 31, and an optical imaging unit 32 that use the same transparent PMN-PT ultrasonic array transducer, wherein optical imaging, ultrasonic imaging, and photoacoustic imaging can be synchronized.
[0038] Specifically, the transparent PMN-PT single crystal 20 uses a multi-element array with ≥8 elements and a center frequency ≥0.5MHz. The transparent conductive film 23 is indium tin oxide, aluminum-doped zinc oxide, fluorine-doped tin oxide, or antimony-doped tin oxide. In short, transparent conductive films are sputtered on the upper and lower surfaces as electrodes, such as indium tin oxide (ITO, In2O3:Sn), aluminum-doped zinc oxide (AZO, ZnO:Al), fluorine-doped tin oxide (FTO, SnO2:F), and antimony-doped tin oxide (ATO, Sn2O:Sb), etc. The transparent backing layer is transparent tempered glass. In short, the surface where the transparent backing layer connects to the transparent PMN-PT single crystal is formed with equally spaced arrays of transparent conductive circuits using photolithography and sputtering processes, and pads are formed at the ends for cable soldering or connector connection to cables, and then connected to the system host via cables. The transparent matching layer is made of polymer epoxy or acrylic plastic, and the thickness of the transparent matching layer is less than or equal to 1 / 4 of the wavelength of the working frequency of the probe. In short, a transparent conductive thin film layer is also coated on the side connected to the transparent PMN-PT as an electrode, and the thickness of the matching layer is about 1 / 4 of the wavelength of the working frequency of the probe.
[0039] In some specific embodiments, a transparent Parylene film 24 is also formed on the surface of the transparent matching layer 22. The Parylene film 24 (which is commercially available and is a conventional product) mainly improves the acoustic matching coupling effect.
[0040] Combination Figure 3 As shown, the photoacoustic imaging unit 31 includes a photoacoustic fiber 310 and a fiber optic projection assembly 311. The photoacoustic fiber 310 is used to transmit near-infrared short-pulse laser required for photoacoustic imaging. The fiber optic projection assembly 311 includes a beam expander a and a confocal lens b. The laser is guided by the fiber and then expanded and collimated before illuminating the transparent PMN-PT ultrasonic array transducer. In some specific embodiments, the beam expander a is a biconcave lens; the confocal convex lens b is a convex lens. In short, the laser is guided by the fiber to the biconcave lens for beam expansion, then collimated by the confocal convex lens, and finally perpendicularly irradiated onto the target through the transparent array transducer, providing uniform and stable laser illumination for photoacoustic imaging.
[0041] The optical imaging unit 32 includes an imaging fiber 320, a dichroic mirror 321, and a CMOS sensor 322. The imaging fiber 320 transmits continuous visible white light required for optical imaging, with a wavelength less than 800 nm. The dichroic mirror 321 is tilted relative to the upper part of the probe body 1, and the angle between the dichroic mirror 321 and the incident angle of the light beam is acute. In some specific embodiments, the angle between the dichroic mirror and the incident angle of the light beam is 45°. When the laser used for photoacoustic imaging shines on the dichroic mirror, since its wavelength is >800 nm, the laser completely passes through the dichroic mirror without reflection. When the white light of optical imaging with a wavelength of 380-750 nm shines on the dichroic mirror, since its wavelength is <800 nm, the light shining on the dichroic mirror undergoes total internal reflection and shines entirely on the target. The light reflected back from the target is reflected by the dichroic mirror and the information is captured by the CMOS sensor for imaging.
[0042] The ultrasonic imaging unit 30 includes an imaging host and a cable 300 for connecting the imaging host to a transparent PMN-PT ultrasonic array transducer. Ultrasonic imaging and photoacoustic imaging can be synchronized. Since optical imaging does not occupy the ultrasonic array probe, optical imaging, ultrasonic imaging and photoacoustic imaging can be synchronized. However, since both ultrasonic imaging and photoacoustic imaging require the ultrasonic array to receive signals, the corresponding imaging timing needs to be controlled to achieve the purpose of rapid imaging.
[0043] Meanwhile, the fabrication method of this transparent photoacoustic multimodal imaging array probe includes the following steps:
[0044] S1. Transducer fabrication
[0045] First, the transparent backing and transparent conductive circuit part are tightly bonded to the transparent PMN-PT with transparent epoxy resin. Then, the array structure is cut according to the set transducer array size using a cutting machine. Then, the transparent matching layer is bonded to the upper surface of the PMN-PT with transparent epoxy resin. The conductive layer is used to connect the cut PMN-PT arrays to form a common ground connection, and the common ground cable is connected at the edge.
[0046] S2, Probe fabrication
[0047] The transparent PMN-PT ultrasonic array transducer and photoacoustic imaging mechanism are assembled in the probe body so that the transparent PMN-PT ultrasonic array transducer can emit and receive ultrasonic waves in ultrasonic imaging mode; receive photoacoustic signals generated by the target in photoacoustic imaging mode; and serve as a transparent protective window in optical imaging mode.
[0048] Example 2
[0049] like Figure 4As shown, the transparent photoacoustic multimodal imaging system of this embodiment includes the transparent photoacoustic multimodal imaging array probe ① of Embodiment 1, the photoacoustic imaging pulsed laser ②, the optical imaging light source ③, and the ultrasonic imaging host ④, wherein the pulsed laser ②, the light source ③, and the host ④ are respectively connected to the transparent photoacoustic multimodal imaging array probe ① through optical fibers or cables.
[0050] Specifically, the pulsed laser is an OPO short-pulse laser, mainly transmitting near-infrared short-pulse laser light required for photoacoustic imaging, such as Nd:YAG 1064nm, or tunable wavelength near-infrared pulsed laser light from an OPO laser. The light source is white light excited by sources such as LEDs or xenon lamps. Simultaneously, for ultrasonic imaging, only the PMN-PT ultrasonic array probe needs to be excited separately, and the received ultrasonic echo can be imaged in conventional B-mode or C-mode. For photoacoustic imaging, the photoacoustic excitation laser needs to be turned on, and the laser's emission timing is controlled by laser pulse triggering or a trigger signal emitted by the host. The PMN-PT ultrasonic array probe then receives the photoacoustic signal generated by the target for photoacoustic imaging. For optical imaging, the illumination source is turned on, and the light illuminating the dichroic mirror undergoes total internal reflection, illuminating the target. The light reflected back from the target is reflected by the dichroic mirror and captured by the CMOS sensor for transmission, thus performing optical imaging.
[0051] When using this transparent photoacoustic multimodal imaging array probe, for ultrasonic imaging, only the PMN-PT ultrasonic array probe needs to be excited individually, and the received ultrasonic echo can be imaged in conventional B-mode or C-mode. For photoacoustic imaging, the photoacoustic excitation laser needs to be turned on, and the laser's emission timing is controlled by laser pulse triggering or a trigger signal emitted by the host. Then, the PMN-PT ultrasonic array probe receives the photoacoustic signal generated by the target for photoacoustic imaging. For optical imaging, the illumination source is turned on, and the light illuminating the dichroic mirror undergoes total internal reflection, illuminating the target. The light reflected back from the target is reflected by the dichroic mirror and captured by the CMOS sensor to transmit the signal for optical imaging. Therefore, one aspect of the present invention... Optical imaging does not occupy the ultrasound array probe, thus fully utilizing the advantages of the light field and ultrasound probe, and is compatible with ultrasound, optical, and photoacoustic imaging. That is, it can form a multimodal composite probe of optical, ultrasound, and photoacoustic modes, and can operate synchronously, making it highly practical. On the other hand, it increases the application scenarios of transparent photoacoustic multimodal imaging array probes, providing high-quality image information for related research and clinical applications, expanding the application fields of transparent photoacoustic probes, and is highly practical. In addition, the device has a simple structure, rich functions, and meets the needs of high-performance multimodal imaging. Thirdly, it makes full use of the transparency and the use of DM dichroic mirrors to allow light of different wavelengths to be irradiated to form the required light or photoacoustic signals to meet the needs of multimodal imaging, and is low in cost and easy to use.
[0052] The present invention has been described in detail above, with the aim of enabling those skilled in the art to understand and implement the invention. However, this description should not be construed as limiting the scope of protection of the invention. All equivalent changes or modifications made in accordance with the spirit and essence of the invention should be included within the scope of protection of the invention.
Claims
1. A transparent photoacoustic multimodal imaging array probe, comprising a probe body, a transducer, and a photoacoustic imaging mechanism, characterized in that, The transducer is a transparent PMN-PT ultrasonic array transducer, and includes a multi-element linear array or phased array transparent PMN-PT single crystal; a transparent backing layer and a transparent matching layer located on both ends of the transparent PMN-PT single crystal; and a transparent conductive film located between the transparent backing layer and the transparent PMN-PT single crystal, and between the transparent PMN-PT single crystal and the transparent matching layer; the photoacoustic imaging mechanism includes an ultrasonic imaging unit, a photoacoustic imaging unit, and an optical imaging unit that use the same transparent PMN-PT ultrasonic array transducer, wherein optical imaging, ultrasonic imaging, and photoacoustic imaging can be synchronized.
2. The transparent photoacoustic multimodal imaging array probe according to claim 1, characterized in that, The number of array elements in a multi-element array is ≥8, and the center frequency is ≥0.5MHz.
3. The transparent photoacoustic multimodal imaging array probe according to claim 1, characterized in that, The transparent conductive film is indium tin oxide, aluminum-doped zinc oxide, fluorine-doped tin oxide, or antimony-doped tin oxide; and / or, the transparent backing layer is transparent tempered glass; and / or, the transparent matching layer is polymer epoxy or acrylic plastic, and the thickness of the transparent matching layer is less than or equal to 1 / 4 of the wavelength of the working frequency of the probe.
4. The transparent photoacoustic multimodal imaging array probe according to claim 1, characterized in that, A transparent Parylene film is also formed on the surface of the transparent matching layer.
5. The transparent photoacoustic multimodal imaging array probe according to claim 1, characterized in that, The photoacoustic imaging unit includes a photoacoustic fiber and a fiber optic projection assembly. The photoacoustic fiber is used to transmit near-infrared short-pulse laser required for photoacoustic imaging. The fiber optic projection assembly includes a beam expander and a confocal lens. The laser is guided by the fiber and then expanded and collimated before irradiating the transparent PMN-PT ultrasonic array transducer.
6. The transparent photoacoustic multimodal imaging array probe according to claim 5, characterized in that, The beam expander is a biconcave lens; the confocal convex lens is a convex lens.
7. The transparent photoacoustic multimodal imaging array probe according to claim 1, characterized in that, The optical imaging unit includes an imaging fiber, a dichroic mirror, and a CMOS sensor. The imaging fiber is used to transmit continuous visible white light required for optical imaging, and the wavelength of the white light is less than 800 nm. The dichroic mirror is relatively tilted and positioned above the probe body, and the angle between the dichroic mirror and the incident angle of the light beam is an acute angle.
8. The transparent photoacoustic multimodal imaging array probe according to claim 7, characterized in that, The angle between the dichroic mirror and the incident angle of the light beam is at least 45°.
9. A method for manufacturing a transparent photoacoustic multimodal imaging array probe according to any one of claims 1 to 8, characterized in that, It includes the following steps: S1. Transducer fabrication First, the transparent backing and transparent conductive circuit part are tightly bonded to the transparent PMN-PT with transparent epoxy resin. Then, the array structure is cut according to the set transducer array size using a cutting machine. Then, the transparent matching layer is bonded to the upper surface of the PMN-PT with transparent epoxy resin. The conductive layer is used to connect the cut PMN-PT arrays to form a common ground connection, and the common ground cable is connected at the edge. S2, Probe fabrication The transparent PMN-PT ultrasonic array transducer and photoacoustic imaging mechanism are assembled in the probe body so that the transparent PMN-PT ultrasonic array transducer can emit and receive ultrasonic waves in ultrasonic imaging mode; receive photoacoustic signals generated by the target in photoacoustic imaging mode; and serve as a transparent protective window in optical imaging mode.
10. A transparent photoacoustic multimodal imaging system, characterized in that, It includes a transparent photoacoustic multimodal imaging array probe as described in any one of claims 1 to 9, a pulsed laser for photoacoustic imaging, a light source for optical imaging, and a host for ultrasonic imaging, wherein the pulsed laser, the light source, and the host are respectively connected to the transparent photoacoustic multimodal imaging array probe via optical fiber or cable; when performing ultrasonic imaging, only the PMN-PT ultrasonic array probe needs to be excited alone, and the received ultrasonic echo can be imaged in conventional B-mode or C-mode; when performing photoacoustic imaging, the photoacoustic excitation laser needs to be turned on, and the laser pulse trigger or the host emits a trigger signal to control the laser's emission timing, and then the PMN-PT ultrasonic array probe receives the photoacoustic signal generated by the target to perform photoacoustic imaging; when performing optical imaging, the illumination source is turned on, the light illuminating the dichroic mirror undergoes total internal reflection, and all of it illuminates the target, while the light reflected back from the target is reflected by the dichroic mirror and captured and transmitted by the CMOS sensor to perform optical imaging.