Ultrasound imaging system

Abstract

The application provides an ultrasonic imaging system, comprising a probe, an excitation ultrasonic device, a detection ultrasonic device and an imaging device, wherein the probe comprises a transmitting optical fiber and a receiving optical fiber. The excitation ultrasonic device is used for sending first laser to the transmitting optical fiber, the first laser comprises a plurality of pulsed laser beams with different wavelengths; the transmitting optical fiber comprises a grating attached with photoacoustic conversion material, and is used for converting the incident first laser into ultrasonic waves through the photoacoustic conversion material, so as to send ultrasonic wave arrays with different focusing ranges to an object to be detected based on the first laser; the receiving optical fiber is used for receiving ultrasonic echoes obtained after the ultrasonic waves reflected by the object to be detected; the detection ultrasonic device is used for sending second laser to the receiving optical fiber, so that the second laser is reflected into detection laser under the action of the ultrasonic echoes; and the imaging device is connected with the detection ultrasonic device, and is used for processing and imaging the detection laser. The ultrasonic imaging system provided by the application can realize ultrasonic imaging with higher sensitivity and a large angle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ultrasonic imaging, in particular to an ultrasonic imaging system. BACKGROUND

[0002] With the development of the technical field of ultrasound, ultrasonic imaging has important significance in preoperative diagnosis.

[0003] In the traditional technology, ultrasonic imaging is generally realized by means of intracavity imaging based on piezoelectric ultrasonic transducers, but this technology has problems such as low ultrasonic detection sensitivity, great influence of electromagnetic interference, difficult impedance matching, and large signal attenuation.

[0004] It can be seen that the current ultrasonic imaging technology has the problem of low sensitivity. SUMMARY

[0005] Therefore, in order to solve the problems in the traditional technology, the present application provides an ultrasonic imaging system which can realize higher transmission bandwidth, higher sensitivity and large-angle ultrasonic imaging.

[0006] An ultrasonic imaging system, characterized in that the system comprises a probe, an excitation ultrasonic device, a detection ultrasonic device and an imaging device, the probe comprises a transmitting optical fiber and a receiving optical fiber, wherein,

[0007] The excitation ultrasonic device is connected with the probe and is used for sending first laser to the transmitting optical fiber, the first laser comprises a plurality of pulsed lasers of different wavelengths;

[0008] The transmitting optical fiber comprises a grating attached with photoacoustic conversion material, is used for converting the incident first laser into ultrasonic waves through the photoacoustic conversion material, and is used for sending ultrasonic wave arrays of different focusing ranges to a to-be-detected object based on the first laser; the receiving optical fiber is used for receiving ultrasonic echoes obtained after the to-be-detected object reflects the ultrasonic waves;

[0009] The detection ultrasonic device is connected with the probe and is used for sending second laser to the receiving optical fiber, so that the second laser is reflected as detection laser under the action of the ultrasonic echoes, and the detection ultrasonic device is also used for receiving the detection laser;

[0010] The imaging device is connected with the detection ultrasonic device and is used for processing and imaging the detection laser.

[0011] In one embodiment, the transmitting optical fiber comprises:

[0012] Multiple first gratings are arranged in an array, and each first grating has a photoacoustic conversion material attached to its surface. The photoacoustic conversion material is used to convert the first laser light irradiated onto the first grating into the ultrasonic wave. The wavelength of the first grating corresponds one-to-one with the wavelength of the pulsed laser light.

[0013] In one embodiment, the receiving optical fiber includes:

[0014] Multiple second gratings are arranged in an array. The second gratings are used to undergo geometric deformation under the action of the ultrasonic echo so that the second laser is reflected by the second grating to obtain the detection laser. The second gratings correspond one-to-one with the first grating.

[0015] In one embodiment, the transmitting optical fiber and the receiving optical fiber are arranged in parallel.

[0016] In one embodiment, the ultrasonic excitation device includes: multiple pulsed lasers and an optical beam combiner, wherein,

[0017] The pulsed laser is used to generate the pulsed laser, and each pulsed laser generates a pulsed laser with a different wavelength;

[0018] The optical beam combiner is used to combine the pulsed lasers into the first laser.

[0019] In one embodiment, the ultrasonic detection device includes: a tunable laser, an optical beam splitter, and an optical fiber circulator, wherein,

[0020] The tunable laser is used to emit a continuous probe laser;

[0021] The optical beam splitter is used to split the continuous probe laser into multiple beams of the second laser;

[0022] The fiber optic circulator is used to output the second laser to the receiving fiber and to output the detection laser to the imaging device.

[0023] In one embodiment, the imaging device includes: a photodetector, a signal amplifier, a data acquisition card, and a computer, wherein,

[0024] The photodetector is used to receive the detection laser and convert the optical signal of the detection laser into an electrical signal.

[0025] The signal amplifier is used to increase the strength of the electrical signal;

[0026] The data acquisition card is used to acquire the electrical signal output by the signal amplifier and quantize the electrical signal into a digital signal;

[0027] The computer is used to receive the digital signals and perform data processing and ultrasound imaging on the digital signals.

[0028] In one embodiment, the second grating is a fiber Bragg grating.

[0029] In one embodiment, the photoacoustic conversion material is a metal thin film or an ultrathin carbon composite material.

[0030] In one embodiment, the system further includes a drive device connected to the probe, the drive device being used to control the movement of the probe.

[0031] The aforementioned ultrasonic imaging system includes: a probe, an ultrasonic excitation device, an ultrasonic detection device, and an imaging device. The probe includes a transmitting optical fiber and a receiving optical fiber. The ultrasonic excitation device is connected to the probe and is used to send a first laser beam to the transmitting optical fiber. The first laser beam includes multiple pulsed laser beams of different wavelengths. The transmitting optical fiber includes a grating with photoacoustic conversion material attached, which is used to convert the incident first laser beam into ultrasonic waves through the photoacoustic conversion material, so as to send ultrasonic wave arrays with different focusing ranges to the object to be detected based on the first laser beam. The receiving optical fiber is used to receive the ultrasonic echo obtained after the ultrasonic waves are reflected by the object to be detected. The ultrasonic detection device is connected to the probe and is used to send a second laser beam to the receiving optical fiber, so that the second laser beam is reflected into a detection laser beam under the action of the ultrasonic echo. The ultrasonic detection device is also used to receive the detection laser beam. The imaging device is connected to the ultrasonic detection device and is used to process and image the detection laser beam. The ultrasonic imaging system provided in this application controls a first laser composed of multiple pulsed lasers of different wavelengths to enter the transmitting optical fiber of the probe through an ultrasonic excitation device. The first laser is converted into an ultrasonic wave array with different focusing ranges by a grating with photoacoustic conversion material attached to the transmitting optical fiber, thereby increasing the angle and range of ultrasonic detection. The receiving optical fiber in the probe receives the ultrasonic waves reflected by the object to be detected and obtains the ultrasonic echo. Based on the change in the phase or power spectrum of the second laser by the ultrasonic echo, a detection laser is obtained. The imaging device receives the detection laser and obtains measurement data along the depth direction of the object to be detected. Based on the measurement data along the depth direction of the object to be detected, an image of the object to be detected is generated, which can achieve ultrasonic imaging with higher sensitivity and a larger angle. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of an ultrasound imaging system in one embodiment of this application.

[0033] Figure 2 This is a schematic diagram of the structure of an ultrasound imaging system in one embodiment of this application. Detailed Implementation

[0034] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented 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 this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0035] The serial numbers assigned to components in this document, such as "first" and "second," are used solely to distinguish the objects being described and do not have any sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing this application and for simplification, 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 application.

[0036] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply 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 that the first feature is at a lower horizontal level than the second feature.

[0037] like Figure 1As shown, this application provides an ultrasonic imaging system 10. The ultrasonic imaging system 10 includes a probe 110, an ultrasonic excitation device 120, an ultrasonic detection device 130, and an imaging device 140. The probe includes a transmitting optical fiber 150 and a receiving optical fiber 160. The ultrasonic excitation device 120 is connected to the probe 110 and is used to send a first laser beam to the transmitting optical fiber 150. The first laser beam includes multiple pulsed laser beams of different wavelengths. The transmitting optical fiber 150 includes a grating with a photoacoustic conversion material attached, used to convert the incident first laser beam into ultrasonic waves through the photoacoustic conversion material, so as to send ultrasonic wave arrays with different focusing ranges to the object to be detected based on the first laser beam. The receiving optical fiber 160 is used to receive the ultrasonic echo obtained after the ultrasonic waves are reflected by the object to be detected. The ultrasonic detection device 130 is connected to the probe and is used to send a second laser beam to the receiving optical fiber 160, so that the second laser beam is reflected as a detection laser beam under the action of the ultrasonic echo. The ultrasonic detection device 130 is also used to receive the detection laser beam. The imaging device 140 is connected to the ultrasonic detection device 130 and is used to process and image the detection laser beam.

[0038] The object to be detected is the target tissue requiring ultrasound imaging, such as blood vessels, bronchi, esophagus, duodenum, and heart chambers within a living organism. The probe 110 is an ultrasound scanning probe, which may also include a housing 111. A transmitting optical fiber 150 and a receiving optical fiber 160 can be disposed inside the housing 111. The transmitting optical fiber 150 receives the first laser emitted by the excitation ultrasound device 120, and the receiving optical fiber 160 receives multiple second laser beams emitted by the detection ultrasound device 130. The transmitting optical fiber 150 may include multiple gratings with attached photoacoustic conversion material. The first laser irradiates the photoacoustic conversion material on the gratings, which converts the light signal into an ultrasonic signal, thus converting the first laser into ultrasonic waves. The multiple ultrasonic waves converted from the multiple first laser beams form an ultrasonic wave array. The excitation ultrasound device 120 can effectively control the shape and direction of the ultrasonic wave array emitted by the transmitting optical fiber 150 by adjusting the spacing between the gratings in the transmitting optical fiber 150, enabling beam scanning, deflection, and focusing of ultrasonic waves, thereby sending ultrasonic wave arrays with different focusing ranges to the object to be detected. The object to be detected reflects ultrasonic waves as ultrasonic echoes. The receiving optical fiber 160 receives these echoes. A second laser beam received by the receiving optical fiber 160 from the ultrasonic detection device 130 can change its phase or power spectrum under the influence of the ultrasonic echo, resulting in a detection laser beam reflected back to the ultrasonic detection device 130. The imaging device 140 receives the detection laser beam sent by the ultrasonic detection device 130 and measures the beam to obtain measurement data along the depth direction of the object to be detected. Based on this measurement data, an ultrasonic image of the object to be detected is generated.

[0039] For example, the diameter of probe 110 can be 0.5mm to 1.5mm, and the length of probe 110 can be 0.2mm to 10mm. Specifically, the diameter of probe 110 can be 0.5mm, 0.7mm, 0.9mm, 1.1mm, 1.3mm, or 1.5mm, and the length of probe 110 can be 0.2mm, 1.2mm, 2.2mm, 3.2mm, 4.2mm, 5.2mm, 6.2mm, 7.2mm, 8.2mm, or 9.2mm. Probe 110 needs to move through narrow objects, requiring it to be small and short. Therefore, if the diameter of the probe 110 is too small, it is not conducive to the processing of the internal structure; if it is too large, it is not conducive to movement and rotation in small objects. At the same time, an excessively large probe also increases the amount of material to be prepared, which is not conducive to reducing costs. Therefore, controlling the diameter of the probe 110 to satisfy the above relationship is beneficial for the movement of the probe 110 in narrow objects to obtain more information about the object's environment, while also helping to control costs. On the other hand, if the probe 110 is too short, it is not conducive to preparation; if it is too long, it cannot pass through objects with curved structures and is prone to damaging the object. Therefore, controlling the length of the probe 110 to satisfy the above relationship is beneficial for the movement of the probe 110 in the object to obtain more information about the object's environment and facilitate imaging.

[0040] The ultrasonic imaging system 10 provided in this application controls a first laser composed of multiple pulsed lasers of different wavelengths to enter the transmitting optical fiber 150 of the probe 110 through an ultrasonic excitation device 120. The first laser is converted into an ultrasonic wave array with different focusing ranges by a grating with photoacoustic conversion material attached to the transmitting optical fiber 150, thereby increasing the angle and range of ultrasonic detection. This allows the receiving optical fiber 160 in the probe 110 to receive the ultrasonic waves reflected by the object to be detected and obtain ultrasonic echoes. Based on the change in the phase or power spectrum of the second laser caused by the ultrasonic echoes, a detection laser is obtained. The imaging device 140 receives the detection laser and obtains measurement data along the depth direction of the object to be detected. Based on the measurement data along the depth direction of the object to be detected, an image of the object to be detected is generated, which can achieve ultrasonic imaging with higher sensitivity and a larger angle.

[0041] In one embodiment, such as Figure 1 As shown, the transmitting fiber 150 includes a plurality of first gratings 151 arranged in an array. Each first grating 151 has a photoacoustic conversion material attached to its surface. The photoacoustic conversion material is used to convert the first laser light irradiated onto the first grating into the ultrasonic wave. The wavelength of each first grating 151 corresponds one-to-one with the wavelength of the pulsed laser light.

[0042] Each first grating 151 on the transmitting fiber 150 is attached with a photoacoustic conversion material. When a first laser irradiates the transmitting fiber 150, pulsed lasers of different wavelengths can enter the corresponding first grating 151. When each pulsed laser irradiates the first grating 151 corresponding to its wavelength, the photoacoustic conversion material can convert the optical signal of the pulsed laser into an ultrasonic signal, thereby converting the pulsed laser into ultrasonic waves to scan the object to be detected. The interior of the transmitting fiber 150 is configured as a laser path, and the first laser entering the transmitting fiber 150 can be converted into ultrasonic waves through the photoacoustic effect and transmitted outward and focused onto the object to be detected.

[0043] Multiple first gratings 151 are arranged in an array as follows: Figure 1 As shown, there is a certain interval between every two first gratings 151, arranged in an array. It should be noted that the spacing between the multiple first gratings 151 is not specifically limited in this embodiment; the spacing between every two first gratings 151 can be the same or different. Since the multiple first gratings 151 are arranged in an array, after the first laser enters the transmitting fiber 150, the time it takes for each pulse laser to reach the corresponding first grating 151 attached to the photoacoustic conversion material is different. That is, the time it takes for different pulse lasers to reach the corresponding first grating 151 can be controlled by adjusting the length of the transmitting fiber 150 or adjusting the spacing between each first grating 151, so that the ultrasonic wave array emitted by the transmitting fiber 150 achieves different focusing ranges.

[0044] Traditional phased array ultrasonic scanning uses piezoelectric crystals, which are based on an electro-acoustic-electro-electric energy conversion process. This technology is relatively complex and has poor resistance to electromagnetic interference. In this embodiment, a transmitting optical fiber 150 is disposed within the probe 110, and multiple first gratings 151 coated with photoacoustic conversion material are arranged in an array within the transmitting optical fiber 150. This achieves a lateral scanning all-optical ultrasonic imaging technology with high lateral resolution and electromagnetic interference resistance. Furthermore, the combination of all-optical and phased array technologies gives the ultrasonic imaging system 10 even better resolution and electromagnetic interference resistance.

[0045] In one embodiment, such as Figure 1 As shown, the receiving optical fiber 160 includes a plurality of second gratings 161. The plurality of second gratings 161 are arranged in an array. The second gratings 161 are used to undergo geometric deformation under the action of ultrasonic echo, so that the second laser is reflected by the second gratings 161 to obtain the detection laser; the second gratings correspond one-to-one with the first gratings.

[0046] For example, the second grating 161 can be a π-fiber Bragg grating (π-FBG). As an optical sensor, it can change the reflection spectrum of the detection laser through its own geometric deformation, thereby achieving the function of detecting the object to be detected. The ultrasonic echo reflected back from the object to be detected hits the second grating 161, causing the second grating 161 to undergo geometric deformation. The second laser shines on the second grating 161 through the receiving fiber 160 and is reflected by the second grating 161 as the detection laser. Compared with the second laser, the phase or power spectrum of the detection laser changes. The detection laser is transmitted in the form of laser light through the receiving fiber 160 in a lossless manner to the ultrasonic detection device 130, and then to the imaging device 140, so that the imaging device 140 receives the sensing information of the detection laser response on the second grating 161. The number of second gratings 161 can be the same as the number of first gratings 151. Each first grating 151 can correspond to one second grating 161.

[0047] Multiple second gratings 161 are arranged in an array as follows: Figure 1 As shown, there is a certain interval between every two second gratings 161, and they are arranged in an array. It should be noted that the spacing between the multiple second gratings 161 is not specifically limited in this embodiment of the present disclosure, and the spacing between every two second gratings 161 can be the same or different.

[0048] In this embodiment, a phased array is formed by multiple first gratings 151 on the transmitting fiber 150 and multiple second gratings 161 on the receiving fiber 160. The first gratings 151 are responsible for emitting ultrasonic waves, and the activation of each first grating 151 can be controlled according to certain rules and timing based on the spacing of the first gratings 151 or the length of the transmitting fiber 151, thereby adjusting the control focal point position and focusing direction to form a focused sound field, i.e., ultrasonic wave arrays with different focusing ranges. The second gratings 161 are responsible for receiving the ultrasonic echoes reflected back from the object to be detected by the corresponding first grating 151 and transmitting them to the ultrasonic detection device 130. Compared to piezoelectric crystals based on the electro-acoustic-electro-electric energy conversion process in conventional technologies, this embodiment combines all-optical and phased array technologies, giving the ultrasonic imaging system 10 better resolution and electromagnetic interference resistance.

[0049] In one embodiment, the transmitting optical fiber 150 and the receiving optical fiber 160 are arranged in parallel.

[0050] For example, the transmitting fiber 150 and the receiving fiber 160 are arranged in parallel within the probe 110. Each first grating 151 in the transmitting fiber 150 may have a corresponding second grating 161 in the receiving fiber 160. When the probe 110 is inserted into the object to be probed, the first grating 151 can emit ultrasonic waves through the sidewall of the probe 110 to a preset area of ​​the object to be probed, and the reflected ultrasonic waves are received by the corresponding second grating 161. By rotating the probe 110, the first grating 151 can emit ultrasonic waves to different areas within the object to be probed, and the reflected ultrasonic echoes can be received by the corresponding second grating 161, thus completing ultrasonic detection in different areas.

[0051] In this embodiment of the present disclosure, two parallel-arranged transmitting optical fibers 150 and receiving optical fibers 160 are provided in the probe 110, which enables the probe 110 to realize all-optical ultrasound imaging technology in the lateral scanning mode, with high lateral resolution and anti-electromagnetic interference capability.

[0052] In one embodiment, such as Figure 2 As shown, the ultrasonic excitation device 120 includes multiple pulsed lasers 124 and an optical beam combiner 123. The pulsed lasers 124 generate pulsed lasers, each with a different wavelength. The optical beam combiner 123 combines the pulsed lasers into a single laser beam.

[0053] Specifically, pulsed laser 124 emits pulsed laser light, and optical combiner 123 combines the pulsed laser light emitted by each pulsed laser 124 into a first laser beam, with each pulsed laser beam retaining the characteristics of the original pulsed laser. The wavelength of the first grating 151 corresponds one-to-one with the wavelength of the pulsed laser. When the first laser light irradiates the transmitting fiber 150, pulsed laser light of different wavelengths can enter the corresponding first grating 151. When each pulsed laser light irradiates the first grating 151 corresponding to its wavelength, the photoacoustic conversion material converts the optical signal of the pulsed laser light into an ultrasonic signal, thus converting the pulsed laser light into ultrasonic waves. Since multiple first gratings 151 are arranged in an array, the time it takes for each pulsed laser light to reach the corresponding first grating 151 with the attached photoacoustic conversion material is different. That is, the time it takes for different pulsed laser light to reach the corresponding first grating 151 can be controlled by adjusting the length of the transmitting fiber 150 or the interval between each first grating 151, so that the ultrasonic wave array emitted by the transmitting fiber 150 achieves different focusing ranges.

[0054] For example, the ultrasonic excitation device 120 may further include a first fiber coupler 121 and a fiber amplifier 122. The first fiber coupler 121 is connected to the fiber amplifier 122 and the transmitting fiber 150. The first fiber coupler 121 is used to couple the first laser into the transmitting fiber 150. The first fiber coupler 121 is an optical device used to distribute or combine optical signal power between different optical fibers. The pulsed laser 124 can be a low-power pulsed laser seed source. Multiple low-power pulsed laser seed sources of different wavelengths can be arranged into an array. The pulsed lasers emitted by each low-power pulsed laser seed source can be combined by the optical combiner 123 and then passed through a broadband fiber amplifier 122 to obtain a high-power pulse, i.e., the first laser.

[0055] When performing an ultrasound examination, the probe 110 can be inserted into the object to be examined. Each pulsed laser 124 emits a pulsed laser, which is sequentially coupled to the transmitting fiber 150 through the optical combiner 123 and the fiber amplifier 122 via the first fiber coupler 121. Each pulsed laser in the first laser illuminates the first grating 151 of the corresponding wavelength, thereby controlling the activation of each first grating 151 in turn. The first laser irradiates the surface of the photoacoustic conversion material on the first grating 151. The photoacoustic conversion material can be a nanoscale metal thin film or an ultrathin carbon composite material. The photoacoustic conversion material converts light energy into sound energy, and through the photoacoustic effect, it efficiently converts its energy into ultrasonic waves and projects and focuses the ultrasonic wave segment onto a preset area within the object to be detected. For example, it can be projected onto the object to be detected or other objects within the object to be detected. The ultrasonic echo reflected from the preset area hits the corresponding second grating 161 on the receiving optical fiber 160, causing the second grating 161 to deform. The second laser hitting the second grating 161 is then reflected as a detection laser, which is detected by the ultrasonic detection device 130 and subsequently transmitted to the imaging device 140.

[0056] In this embodiment, multiple pulsed lasers with different wavelengths are generated by using multiple pulsed lasers. After the first laser enters the transmitting fiber 150, each pulsed laser irradiates the corresponding first grating 151 at a certain time interval. The pulsed laser excites the surface of the photoacoustic conversion material on the first grating 151, causing the pulsed laser to generate ultrasonic waves on the surface of the photoacoustic conversion material. This can effectively control the shape and direction of the ultrasonic wave array emitted towards the object to be detected, and can realize the beam scanning, deflection and focusing of ultrasonic waves, achieving higher transmission bandwidth, higher sensitivity and large-angle ultrasonic imaging. At the same time, the use of a full optical ultrasonic imaging structure gives the ultrasonic imaging system 10 advantages such as high resolution, large detection depth, high sensitivity and strong anti-interference ability.

[0057] In one embodiment, such as Figure 2As shown, the ultrasonic detection device 130 includes a tunable laser 135, an optical beam splitter 133, and an optical fiber circulator 131. The tunable laser 135 emits a continuous probe laser. The optical beam splitter 133 splits the continuous probe laser into multiple second laser beams. The optical fiber circulator 131 outputs the second laser beams to a receiving optical fiber 160 and outputs the detection laser beams to an imaging device 140.

[0058] Specifically, the tunable laser 135 can emit a continuous probe laser with a variable wavelength or frequency. The optical beam splitter 133 is used to split a single continuous probe laser into multiple second laser beams, each of which retains the characteristics of the original continuous probe laser. The fiber optic circulator 131 enables bidirectional optical signal transmission over a single fiber. Ends 1-2 of the fiber optic circulator 131 can output the second laser beams to the second grating 161 of the receiving fiber optic 160. Ends 2-3 of the fiber optic circulator 131 can transmit the detection laser beam reflected back from the second grating 161 to the imaging device 140 in a lossless manner.

[0059] In this embodiment, the ultrasonic detection device 130 may further include a second fiber coupler 132 and a beam shaping system 134. The second fiber coupler 132 is connected to the optical beam splitter 133 and the fiber optic circulator 131, and is used to couple a second laser beam into the fiber optic circulator 131. Specifically, the second fiber coupler 132 is an optical device used to distribute or combine optical signal power among different optical fibers. The beam shaping system 134 is used to change the spatial distribution of beam energy.

[0060] For example, a tunable laser 135 emits a continuous probe laser beam, which passes sequentially through a beam shaping system 134, an optical beam splitter 133, and then is coupled into the optical fiber of an optical fiber circulator 131 via a second optical fiber coupler 132. The optical fiber outputs the second laser beam through ends 1-2 of the optical fiber circulator 131 to the second grating 161 of the receiving optical fiber 160. The second grating 161 acts as an optical sensor, and its reflected spectrum transmits the responded sensing information in the form of laser light through the receiving optical fiber 160 and ends 2-3 of the optical fiber circulator 131 to the imaging device 140 in a lossless manner.

[0061] In this embodiment of the disclosure, by designing the ultrasonic detection device 130, the receiving optical fiber 160, the imaging device 140, etc., a full optical ultrasonic imaging is realized, which has the advantages of high resolution, large detection depth, high sensitivity, and strong anti-interference ability. It solves the shortcomings of traditional technology based on piezoelectric ultrasonic transducers for intracavity imaging, namely, low ultrasonic detection sensitivity, great influence of electromagnetic interference, difficulty in impedance matching, and large signal attenuation.

[0062] In one embodiment, such as Figure 2As shown, the imaging device 140 includes a photodetector 141, a signal amplifier 142, a data acquisition card 143, and a computer 144. The photodetector 141 receives the detection laser and converts the optical signal of the detection laser into an electrical signal. The signal amplifier 142 increases the intensity of the electrical signal. The data acquisition card 143 acquires the electrical signal output from the signal amplifier 142 and quantizes the electrical signal into a digital signal. The computer 144 receives the digital signal and performs data processing and ultrasound imaging on the digital signal.

[0063] Specifically, the imaging device 140 is used for data processing and imaging using the output data of the photodetector 141. The signal amplifier 142 is used to increase the strength of the electrical signal and enhance the communication capability of the imaging device 140. The data acquisition card 143 is used to acquire and quantize the analog electrical signal output from the signal amplifier 142 into a digital signal, and import it into the computer 144. The computer 144 is used for subsequent digital signal processing and for two-dimensional and three-dimensional imaging.

[0064] In this embodiment of the present disclosure, the detection laser transmitted by the detection ultrasound device 130 is processed and imaged by the imaging device 140 to achieve a full optical ultrasound imaging, which has the advantages of high resolution, large detection depth, high sensitivity and strong anti-interference ability.

[0065] In one embodiment, the second grating 161 is a fiber Bragg grating.

[0066] It should be noted that the second grating 161 can be of various forms, as long as it can function as an optical sensor to receive ultrasonic echoes. Taking a fiber Bragg grating (FBG) as an example, the FBG utilizes the photosensitivity of fiber materials. It is a grating device that forms a permanent periodic change in refractive index along the core diameter axis through ultraviolet exposure. Essentially, it forms a narrow-band reflective optical filter within the core diameter. The sensing process of the FBG obtains sensing information by modulating its wavelength through external parameters (such as stress and temperature). Therefore, the FBG is a wavelength-modulated fiber optic sensor. When an ultrasonic echo acts on the FBG, the grating period changes through geometric deformation, and the effective refractive index changes through the photoelastic effect, ultimately causing a shift in the Bragg wavelength. The ultrasonic echo sound pressure acting on the second grating 161 can be demodulated using the amount of Bragg wavelength shift. The most commonly used type of Bragg fiber grating is π-FBG. The effective grating length of a π-FBG sensor is much shorter than its actual grating length, which allows for better response to wide-bandwidth ultrasound. Furthermore, since the sensitivity of a laser-based demodulation system is positively correlated with the slope of the π-FBG reflection spectrum, the steep slope of the π-FBG in the Bragg wavelength peak region effectively improves the sensitivity of the sensor system, thereby enhancing the sensitivity of the entire ultrasound imaging system 10.

[0067] Furthermore, optical fibers, which transmit optical signals, are non-conductive, exhibiting the excellent characteristics of being passive electrical components. The effects of spatially varying electric and magnetic fields on π-FBGs are extremely weak, thus eliminating electromagnetic interference. On the other hand, π-FBGs have higher sensitivity per unit area than piezoelectric transducers. For example, a piezoelectric element with a diameter of 1 mm for ultrasonic detection can provide an equivalent pressure of 1.8 kPa, while a fiber-optic-based π-FBG sensor can provide an equivalent pressure of 100 Pa with a sensing area of ​​only 0.13 × 0.27 m². 2 .

[0068] In this embodiment of the disclosure, the sensitivity and electromagnetic interference resistance of the ultrasound imaging system 10 are improved by using a fiber Bragg grating as the second grating 161.

[0069] In one embodiment, the photoacoustic conversion material is a metal thin film or an ultrathin carbon composite material.

[0070] Specifically, the photoacoustic conversion material attached to the first grating 151 may include a metal thin film or an ultrathin carbon composite material, and the metal thin film and ultrathin carbon composite material are preferably in the nanoscale.

[0071] In this embodiment of the disclosure, since ultrasonic waves generated by optical means have a wider bandwidth than ultrasonic waves generated by electrical means, by setting a photoacoustic conversion material in the ultrasonic imaging system 10, ultrasonic imaging with a higher transmission bandwidth can be achieved, thereby improving the sensitivity of ultrasonic imaging.

[0072] In one embodiment, the ultrasound imaging system 10 further includes a drive device. The drive device is connected to the probe 110 and is used to control the movement of the probe 110.

[0073] For example, in endoscopic ultrasound imaging, endoscopic probes are generally divided into two types: mechanically rotating and phased array. The probe 110 can be a phased array type, and the driving device can control the advance and retraction of the probe 110. Furthermore, the driving device can drive the probe 110 to move at a speed of 0.1 mm / s to 10 mm / s. This ensures the image quality of the acquired image and saves imaging time. If the speed is below the lower limit, the slow advance and retraction speed will increase the overall imaging time, while the fast advance and retraction speed will reduce the quality of the three-dimensional image.

[0074] In this embodiment of the present disclosure, the movement and retraction of the probe 110 are controlled by a driving device, which ensures the image quality of the generated ultrasound image and saves imaging time.

[0075] To facilitate further understanding, this application provides a complete embodiment. The ultrasonic imaging system 10 provided in this embodiment combines phased array and all-optical technology, and is an all-optical ultrasonic phased array imaging system. The ultrasonic imaging system 10 includes a probe 110, an ultrasonic excitation device 120, an ultrasonic detection device 130, and an imaging device 140. The probe 110 includes a housing 112, a transmitting optical fiber 150, and a receiving optical fiber 160. The transmitting optical fiber 150 is responsible for transmitting ultrasound, and the receiving optical fiber 160 is responsible for receiving ultrasound. The ultrasonic excitation device 120 generates multiple pulsed lasers of different wavelengths through multiple pulsed lasers 124. Each pulsed laser is combined into a first laser after passing through an optical combiner 123 and an optical fiber amplifier 122. The first laser enters the transmitting optical fiber 150 through a first optical fiber coupler 121. Each pulsed laser in the first laser irradiates a first grating 151 of the corresponding wavelength to excite the surface of the photoacoustic conversion material, so that the pulsed laser generates ultrasonic waves on the surface of the photoacoustic conversion material. After the ultrasonic waves irradiate the target object, they generate ultrasonic echoes. Since the first gratings 151 are arranged in an array within the transmitting fiber 150, the opening of each first grating 151 can be controlled in a specific timing sequence by adjusting the spacing between the first gratings 151 or the length of the transmitting fiber 150, thereby achieving ultrasonic arrays with different focusing ranges and increasing the angle and range of ultrasonic detection. The ultrasonic detection device 130 detects changes in the second grating 161 on the receiving fiber 160 based on the ultrasonic echo, causing a change in the phase or power spectrum of the second laser, resulting in a detection laser. This change is then converted into an electrical signal by a photodetector 141, amplified, and transmitted to a data acquisition card 143, and finally to a computer 144 for ultrasonic imaging. This application provides a miniaturized, all-optical ultrasonic imaging method with high bandwidth and high detection sensitivity, allowing for high-resolution pulse-echo ultrasonic imaging of soft tissue, which is of profound significance to the field of ultrasonic imaging.

[0076] The embodiments described above are merely illustrative of several implementations of the present invention. Although the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An ultrasound imaging system, characterized in that, The system includes: a probe, an ultrasonic excitation device, an ultrasonic detection device, and an imaging device. The probe includes a transmitting optical fiber and a receiving optical fiber. The ultrasonic excitation device is connected to the probe and is used to send a first laser to the transmitting optical fiber, the first laser comprising multiple pulsed lasers of different wavelengths; The transmitting optical fiber includes a plurality of first gratings, and each first grating has a photoacoustic conversion material attached to its surface. The photoacoustic conversion material is used to convert the first laser irradiated onto the first grating into ultrasonic waves. The ultrasonic excitation device controls the time when different pulsed lasers reach the corresponding first gratings by adjusting the spacing of the first gratings in the transmitting optical fiber or by adjusting the length of the transmitting optical fiber, thereby controlling the shape and direction of the ultrasonic wave array transmitted by the transmitting optical fiber, and transmitting ultrasonic wave arrays with different focusing ranges to the object to be detected based on the first laser; the receiving optical fiber is used to receive the ultrasonic echo obtained after the ultrasonic wave is reflected by the object to be detected. The ultrasonic detection device is connected to the probe and is used to send a second laser to the receiving optical fiber so that the second laser is reflected as a detection laser under the action of the ultrasonic echo. The ultrasonic detection device is also used to receive the detection laser. The imaging device is connected to the detection ultrasound device and is used to process and image the detection laser.

2. The ultrasound imaging system as described in claim 1, characterized in that, Multiple first gratings are arranged in an array, and the wavelengths of the first gratings correspond one-to-one with the wavelengths of the pulsed laser.

3. The ultrasound imaging system as described in claim 1, characterized in that, The receiving optical fiber includes: Multiple second gratings are arranged in an array. The second gratings are used to undergo geometric deformation under the action of the ultrasonic echo so that the second laser is reflected by the second grating to obtain the detection laser. The second gratings correspond one-to-one with the first grating.

4. The ultrasound imaging system as described in claim 1, characterized in that, The transmitting optical fiber and the receiving optical fiber are arranged in parallel.

5. The ultrasound imaging system as described in claim 2, characterized in that, The ultrasonic excitation device includes: multiple pulsed lasers and an optical beam combiner, wherein, The pulsed laser is used to generate the pulsed laser, and each pulsed laser generates a pulsed laser with a different wavelength; The optical beam combiner is used to combine the pulsed lasers into the first laser.

6. The ultrasound imaging system as described in claim 3, characterized in that, The ultrasonic testing device includes: a tunable laser, an optical beam splitter, and an optical fiber circulator, wherein... The tunable laser is used to emit a continuous probe laser; The optical beam splitter is used to split the continuous probe laser into multiple beams of the second laser; The fiber optic circulator is used to output the second laser to the receiving fiber and to output the detection laser to the imaging device.

7. The ultrasound imaging system as described in claim 1, characterized in that, The imaging device includes: a photodetector, a signal amplifier, a data acquisition card, and a computer, wherein, The photodetector is used to receive the detection laser and convert the optical signal of the detection laser into an electrical signal. The signal amplifier is used to increase the strength of the electrical signal; The data acquisition card is used to acquire the electrical signal output by the signal amplifier and quantize the electrical signal into a digital signal; The computer is used to receive the digital signals and perform data processing and ultrasound imaging on the digital signals.

8. The ultrasound imaging system as described in claim 3, characterized in that, The second grating is a fiber Bragg grating.

9. The ultrasound imaging system as described in claim 2, characterized in that, The photoacoustic conversion material is a metal thin film or an ultrathin carbon composite material.

10. The ultrasound imaging system as claimed in claim 1, characterized in that, The system also includes a drive device connected to the probe, which is used to control the movement of the probe.

Images