技术领域technical field
本发明涉及一种无损的快速成像技术，特别涉及一种基于面阵超声探测器的快速三维光声成像系统及方法。The invention relates to a non-destructive fast imaging technology, in particular to a fast three-dimensional photoacoustic imaging system and method based on an area array ultrasonic detector.
背景技术Background technique
光声成像作为一种新颖的无损物质结构检测技术，近十几年来得到了很大的发展，光声成像基于光致声效应的原理，当用脉冲激光或周期性强度调制光来照射某种物质时，该物质内具有光能吸收特性的部分产生周期性的瞬间温度变化，从而使得此处的光吸收介质与周围物质因热胀产生周期性的应力或压力的变化，最后由这种作用力变化而生成超声信号，就是光声信号。光声效应实际上是一种光能-声能的转化过程。光声信号不同于一般的超声信号，这种由光调控而产生的声信号携带有物质组分的光吸收特性，而光吸收特性又与物体的颜色、力学特性、结构形态等相关。光声成像正是一种基于以上原理，用脉冲激光作为激发源，以被接收超声为信息载体，通过相应图像重建算法重组出组织内部吸收特性结构的影像技术。光声成像克服了某些传统成像方法的缺点，比如：与光学相干层析成像(OCT)相比，由于组织光学强散射性造成OCT的测量深度限制在毫米量级的浅层，而光声成像技术可达厘米量级；与纯超声成像相比，在声阻抗差异不大的区域，超声图像的对比度很低，而光声技术利用不同组织的吸收差异能提供高对比度的重建图像。同时，光声成像技术结合了以上两种成像技术的优点，即：OCT具有的无损伤、高选择性激发特性和超声成像具有的低衰减、高穿透性。用超声探测器检测低衰减，低散射的超声波，再结合不同物质光学吸收参数的差异，就能使光声技术在厘米量级的成像深度上提供高分辨，高对比度的结构影像。目前光声成像已经用于显微成像，功能成像及分子成像等领域，同时运用于各领域的成像仪器与装置也同步获得了较快发展。As a novel non-destructive material structure detection technology, photoacoustic imaging has been greatly developed in the past ten years. Photoacoustic imaging is based on the principle of photoacoustic effect. When it is a substance, the part with light energy absorption characteristics in the substance produces periodic instantaneous temperature changes, so that the light-absorbing medium here and the surrounding substances produce periodic stress or pressure changes due to thermal expansion, and finally by this effect The ultrasonic signal is generated by changing the force, which is the photoacoustic signal. The photoacoustic effect is actually a conversion process of light energy to sound energy. The photoacoustic signal is different from the general ultrasonic signal. The acoustic signal generated by light regulation carries the light absorption characteristics of the material components, and the light absorption characteristics are related to the color, mechanical properties, and structural shape of the object. Photoacoustic imaging is a kind of imaging technology based on the above principles, using pulsed laser as the excitation source, using the received ultrasound as the information carrier, and reconstructing the internal absorption characteristic structure of the tissue through the corresponding image reconstruction algorithm. Photoacoustic imaging overcomes the shortcomings of some traditional imaging methods. For example, compared with optical coherence tomography (OCT), the measurement depth of OCT is limited to a shallow layer on the order of millimeters due to the strong optical scattering of tissues. Imaging technology can reach the centimeter level; compared with pure ultrasound imaging, in areas with little difference in acoustic impedance, the contrast of ultrasound images is very low, while photoacoustic technology can provide high-contrast reconstructed images by utilizing the absorption differences of different tissues. At the same time, photoacoustic imaging technology combines the advantages of the above two imaging technologies, namely: the non-invasive and highly selective excitation characteristics of OCT and the low attenuation and high penetration of ultrasound imaging. Using ultrasonic detectors to detect low-attenuation and low-scattering ultrasonic waves, combined with the differences in optical absorption parameters of different substances, enables photoacoustic technology to provide high-resolution, high-contrast structural images at centimeter-level imaging depths. At present, photoacoustic imaging has been used in the fields of microscopic imaging, functional imaging and molecular imaging, and the imaging instruments and devices used in various fields have also achieved rapid development simultaneously.
现在光声成像装置主要分为以单元换能器和线阵多元换能器为超声探测器件的两大类。对于以水听器作为传感器的光声装置主要由脉冲激光器，水听器，信号放大器，信号采集与处理设备，图像重建软件构成；而以线形阵列探测器为传感器的光声装置主要由脉冲激光器，线阵换能器，多通道并行或者扫描采集系统，图像重建软件构成。以上两种装置都可以用于二维和三维的光声成像，但是要获得一帧完整的图像往往要花很长时间进行信号检测，这是由于在信号采集的过程中需要移动探测器以收集不同位置处的超声信号，再经过合适的算法来重建图像。移动探测器一般是采取断层360°旋转扫描或者平面点扫的方式，但是无论哪种方式都存在数据采集时间长，实验装置与成像算法复杂等缺点。并且长时间的机械扫描和数据采集过程中，机械振动、电子设备稳定性、工作点漂移等不可避免的因素都会给成像结果带来随机误差，从而影响重建图像的质量和成像结果的可靠性与真实性。最近出现的二维探测器具有不同深度横向层析成像的能力，但是却要借助于硬件信号延时电路来实现对不同采集深度信号的选择成像，实际上也很难做到快速与实时成像。At present, photoacoustic imaging devices are mainly divided into two categories, which use unit transducers and linear array multi-element transducers as ultrasonic detection devices. For photoacoustic devices using hydrophones as sensors, they are mainly composed of pulsed lasers, hydrophones, signal amplifiers, signal acquisition and processing equipment, and image reconstruction software; while photoacoustic devices using linear array detectors as sensors are mainly composed of pulsed lasers. , linear array transducer, multi-channel parallel or scanning acquisition system, and image reconstruction software. Both of the above two devices can be used for two-dimensional and three-dimensional photoacoustic imaging, but it often takes a long time to perform signal detection to obtain a complete frame of image, which is due to the need to move the detector in the process of signal acquisition to collect Ultrasonic signals at different positions are then reconstructed with appropriate algorithms. Mobile detectors generally adopt the method of tomographic 360°rotation scanning or plane point scanning, but no matter which method has the disadvantages of long data acquisition time, complicated experimental equipment and imaging algorithm, etc. Moreover, during the long-term mechanical scanning and data acquisition process, inevitable factors such as mechanical vibration, electronic equipment stability, and working point drift will bring random errors to the imaging results, thereby affecting the quality of the reconstructed image and the reliability and reliability of the imaging results. authenticity. Recently, two-dimensional detectors have the capability of lateral tomography at different depths, but they need to rely on hardware signal delay circuits to realize selective imaging of signals at different acquisition depths. In fact, it is difficult to achieve fast and real-time imaging.
对于以上所提及传统光声成像的不足，本发明所提出的一种基于平面探测器和三维相控成像方法能实现快速的三维图像重建，硬件的平面探测器结合软件的三维相控算法就能直接完成三维图像显示。这种快速的光声成像方法和装置对于实现光声技术的仪器化，临床化，有着巨大的推动作用。For the shortcomings of traditional photoacoustic imaging mentioned above, a method based on planar detectors and 3D phase-controlled imaging proposed by the present invention can realize fast 3D image reconstruction. Can directly complete the three-dimensional image display. This rapid photoacoustic imaging method and device has a huge role in promoting the instrumentation and clinical application of photoacoustic technology.
发明内容Contents of the invention
为了弥补现有光声成像技术的缺点与不足，本发明的首要目的在于提供一种基于面阵超声探测器的快速三维光声成像方法；利用该方法，任何位于平面探测器信号采集空间范围内的光声源都能快速实时地被重构出来。In order to make up for the shortcomings and deficiencies of the existing photoacoustic imaging technology, the primary purpose of the present invention is to provide a fast three-dimensional photoacoustic imaging method based on an area array ultrasonic detector; All photoacoustic sources can be reconstructed quickly and in real time.
本发明的另一目的在于提供一种实现上述基于面阵超声探测器的快速三维光声成像方法的系统。Another object of the present invention is to provide a system for implementing the above-mentioned fast three-dimensional photoacoustic imaging method based on an area array ultrasonic probe.
为了实现上述目的，本发明采用以下技术方案：一种基于面阵超声探测器的快速三维光声成像方法，包括以下操作步骤：In order to achieve the above object, the present invention adopts the following technical solution: a fast three-dimensional photoacoustic imaging method based on an area array ultrasonic probe, comprising the following steps:
(1)将面阵超声探测器固定在被测物体的表面，面阵超声探测器与被测物体间充满超声耦合液；(1) Fix the area array ultrasonic probe on the surface of the measured object, and fill the ultrasonic coupling liquid between the area array ultrasonic probe and the measured object;
(2)由激光器所发出的激光脉冲通过空间光学系统或光纤光学系统进行波束整形后，使其于探测器的前向均匀照射被测物体，激发被测物体产生光声信号；(2) After the laser pulse emitted by the laser is beam-shaped through the space optical system or the fiber optic system, it irradiates the measured object uniformly in front of the detector, and excites the measured object to generate a photoacoustic signal;
(3)面阵超声探测器的各个子阵元同时收集光声信号，转化为电信号后，通过多通道并行采集电路传输储存到计算机中；(3) Each sub-array element of the area array ultrasonic detector collects the photoacoustic signal at the same time, converts it into an electrical signal, and transmits and stores it to the computer through a multi-channel parallel acquisition circuit;
(4)对采集的光声信号进行处理，利用三维相控重建算法快速重构出被测物体的结构图像或被测物体内不同光吸收成分的分布情况。(4) Process the collected photoacoustic signal, and use the three-dimensional phase control reconstruction algorithm to quickly reconstruct the structural image of the measured object or the distribution of different light absorption components in the measured object.
步骤(1)所述面阵超声探测器通过固定支架与三维扫描平台相连，通过计算机的LABVIEW软件控制程序带动步进电机调整探测器的空间位置(利用此平台可以调整探测器与样品的距离，同时可以使探测器方便的自由移动，从而使任意区域内的吸收体都可以被重建出来。)；所述面阵超声探测器是多阵元平面分布的阵列超声探测器，其阵元的排列为圆形、长方形或正方形的平面方式(探测面形状可根据被测物体的特性来进行定制)。Step (1) said area array ultrasonic probe is connected with three-dimensional scanning platform through fixed support, drives the stepper motor to adjust the spatial position of probe by the LABVIEW software control program of computer (using this platform can adjust the distance between probe and sample, At the same time, the detector can be freely moved conveniently, so that the absorber in any region can be reconstructed.); The area array ultrasonic detector is an array ultrasonic detector with multi-array element planar distribution, and the arrangement of the array elements It is a circular, rectangular or square plane (the shape of the detection surface can be customized according to the characteristics of the measured object).
步骤(2)所述激光器是脉冲激光器，所述激光脉冲波长范围为400～2500nm(可根据被测物体的属性选择任意波长的激光进行激发光声信号)；步骤(1)所述超声耦合液为水。The laser in step (2) is a pulsed laser, and the wavelength range of the laser pulse is 400-2500nm (the laser of any wavelength can be selected according to the properties of the object to be measured to excite the photoacoustic signal); the ultrasonic coupling liquid in step (1) for water.
步骤(3)所述收集是采用多阵元同时并行接收光声信号，光声信号转化为电信号后的数据处理是利用多通道并行电路实现同时的传输和储存。The collection in step (3) is to use multiple array elements to simultaneously receive photoacoustic signals in parallel, and the data processing after the photoacoustic signals are converted into electrical signals is to use multi-channel parallel circuits to realize simultaneous transmission and storage.
步骤(4)所述对采集的数据进行处理，是通过MATLAB程序利用三维相控重建算法得出待测部位的三维重建图像或者横/纵向层析图像；所述三维相控重建算法是通过计算距离面阵超声探测器不同距离的信号值与每一个阵元的采集权重(相位延时)，再依据每一个信号值的采集权重把对应的光吸收部分利用不同权重的投影值相干叠加重建图像。The described processing of the collected data in step (4) is to use the three-dimensional phase control reconstruction algorithm to obtain the three-dimensional reconstruction image or the horizontal/longitudinal tomographic image of the part to be measured by the MATLAB program; the three-dimensional phase control reconstruction algorithm is obtained by calculating The signal value at different distances from the area array ultrasonic detector and the acquisition weight (phase delay) of each array element, and then according to the acquisition weight of each signal value, the corresponding light absorption part is coherently superimposed with the projection value of different weights to reconstruct the image .
步骤(2)所述激光脉冲通过波束整形，与面阵超声探测器的探测面阵镶嵌构成一体化的探头，达到与探测面阵相匹配的均匀照射模式后，均匀照射被测物体。In step (2), the laser pulses are beam-shaped and inlaid with the detection array of the area array ultrasonic detector to form an integrated probe, and after reaching a uniform irradiation mode matching the detection array, the measured object is evenly irradiated.
一种实现上述的基于面阵超声探测器的快速三维光声成像方法的系统，该系统由光声源产生器件、光声信号采集设备和图像处理及重建组件依次电气连接而成。A system for implementing the above-mentioned fast three-dimensional photoacoustic imaging method based on an area array ultrasonic detector, the system is composed of a photoacoustic source generating device, a photoacoustic signal acquisition device, and image processing and reconstruction components that are electrically connected in sequence.
所述光声源产生器件包括激光器、光学系统和一体化探头；所述光声信号采集设备由面阵超声探测器、三维扫描平台、多通道并行实时采集电路和计算机依次电气连接而成。The photoacoustic source generating device includes a laser, an optical system, and an integrated probe; the photoacoustic signal acquisition device is composed of an area array ultrasonic detector, a three-dimensional scanning platform, a multi-channel parallel real-time acquisition circuit, and a computer that are electrically connected in sequence.
所述激光器为可调谐脉冲激光器或调制连续激光器；所述光学系统为空间光束调整系统或限制性光纤光学系统；所述面阵超声探测器通过固定支架与三维扫描平台相连，采用LABVIEW数据采集控制程序实现光声信号的采集，并且操纵步进电机带动三维平台运动。The laser is a tunable pulse laser or a modulated continuous laser; the optical system is a spatial beam adjustment system or a restricted fiber optic system; the area array ultrasonic detector is connected to a three-dimensional scanning platform through a fixed bracket, and is controlled by LABVIEW data acquisition The program realizes the collection of photoacoustic signals, and manipulates the stepper motor to drive the three-dimensional platform to move.
所述图像处理及重建组件为计算机内编有的三维相控重建算法的MATLAB程序。The image processing and reconstruction component is the MATLAB program of the three-dimensional phase control reconstruction algorithm programmed in the computer.
步骤(3)中，面阵探测器由64个压电的方形阵元构成，以8×8的形式均匀分布在1cm2的矩形区域内，阵元的尺寸和阵元之间的间距都是0.984mm，每个探测阵元的信号接收角度为14°；探测器的主频是7.5MHz，带宽是60％；并行采集设备是用LABVIEW软件控制的64通道实时采集电路，探测器上的每一个阵元通过电缆线与采集电路的通道一一对应，每路信号通过采集电路完成模拟信号到数字信号的转化，以及信号的前置放大处理。In step (3), the area array detector is composed of 64 piezoelectric square array elements, which are evenly distributed in a rectangular area of 1cm2 in the form of 8×8. The size of the array elements and the spacing between the array elements are 0.984mm, the signal receiving angle of each detection array element is 14°; the main frequency of the detector is 7.5MHz, and the bandwidth is 60%; the parallel acquisition device is a 64-channel real-time acquisition circuit controlled by LABVIEW software, and each detector on the detector An array element is in one-to-one correspondence with the channels of the acquisition circuit through the cable, and each signal passes through the acquisition circuit to complete the conversion of analog signal to digital signal and the pre-amplification processing of the signal.
本发明的作用原理是：光声激发源产生脉冲激光(波长，重复频率可依据实际情况选择)，通过空间光学系统或限制性光纤光学系统进行波束整形，使其均匀照射到被测物体上，其内部吸收物质由于光声效应而产生光声信号，并经超声耦合剂传播到位于样品上方的平面探测器；接收的信号直接经多通道并行采集系统预处理后传输到计算机中；最后利用三维相控图像算法重建出检测部位的光声图像。本发明适用于大区域复杂部位的快速检测，可以实现非扫描的三维光声图像，克服长时间的信号采集给检测带来的不稳定因素。The working principle of the present invention is: the photoacoustic excitation source generates pulsed laser light (wavelength and repetition frequency can be selected according to the actual situation), and performs beam shaping through a space optical system or a restricted fiber optic system to uniformly irradiate the measured object. Its internal absorbing material generates photoacoustic signals due to the photoacoustic effect, and propagates to the planar detector above the sample through the ultrasonic coupling agent; the received signals are directly preprocessed by the multi-channel parallel acquisition system and then transmitted to the computer; finally, the three-dimensional The photoacoustic image of the detected part is reconstructed by the phase-controlled image algorithm. The invention is suitable for rapid detection of complex parts in a large area, can realize a non-scanning three-dimensional photoacoustic image, and overcomes unstable factors brought about by long-term signal acquisition to detection.
本发明的成像系统和成像方法与现有技术相比具有如下的优势：Compared with the prior art, the imaging system and imaging method of the present invention have the following advantages:
(1)本发明最重要的创新点是建立了以面阵探测器为基础的非扫描光声成像系统。平面方式分布的传感器阵元与多通道并行采集电路的电气连接使一个脉冲激光就能实现空间多点光声信号的接收，实现了快速的信号采集。(1) The most important innovation of the present invention is the establishment of a non-scanning photoacoustic imaging system based on an area array detector. The electrical connection between the sensor array elements distributed in a planar manner and the multi-channel parallel acquisition circuit enables a single pulsed laser to receive photoacoustic signals at multiple points in space, and realizes fast signal acquisition.
(2)本发明在系统装置的基础上，提出了利用三维相控算法的快速光声成像方法。利用此算法能快速的重建出结构复杂的物质组织内部光吸收空间分布情况，同时也使得此套装置在每次的信号采集和图像重建中拥有快速断层扫描功能。与传统的成像技术相比，具有高分辨率，高对比度，高探测深度的优势；与传统的光声技术相比，也克服了成像速度慢，处理数据冗余，算法复杂的缺点。(2) On the basis of the system device, the present invention proposes a fast photoacoustic imaging method using a three-dimensional phase control algorithm. Using this algorithm can quickly reconstruct the spatial distribution of light absorption inside the material tissue with complex structure, and also makes this device have a fast tomographic scanning function in each signal acquisition and image reconstruction. Compared with traditional imaging technology, it has the advantages of high resolution, high contrast, and high detection depth; compared with traditional photoacoustic technology, it also overcomes the shortcomings of slow imaging speed, redundant processing data, and complex algorithms.
(3)本发明适用于常规的物体成分或结构的快速无损检测，无需破坏检测对象。(3) The present invention is suitable for rapid non-destructive detection of conventional object components or structures without destroying the detection object.
(4)本发明装置造价低廉，操作简便，利于广泛使用。(4) The device of the present invention is cheap in cost, easy to operate, and beneficial to wide use.
附图说明Description of drawings
图1是基于面阵超声探测器的快速三维光声成像系统的原理框图，其中1-1是激光器，2-1是介质膜高反镜，2-2是激光分束镜(当光沿45°入射时，透射光和反射光的强度相同)，2-3是实验样品，2-4是扩束镜，2-5为超声耦合液，3-1是平面探测器，4-1是并行采集电路，5-1是PC机(个人计算机)，6-1是步进电机，6-2是二维扫描平台。Fig. 1 is a schematic block diagram of a fast three-dimensional photoacoustic imaging system based on an area array ultrasonic detector, wherein 1-1 is a laser, 2-1 is a dielectric film high reflection mirror, and 2-2 is a laser beam splitter (when the light is along the 45 °When incident, the intensity of transmitted light and reflected light is the same), 2-3 is the experimental sample, 2-4 is the beam expander, 2-5 is the ultrasonic coupling liquid, 3-1 is the plane detector, 4-1 is the parallel Acquisition circuit, 5-1 is a PC (personal computer), 6-1 is a stepper motor, and 6-2 is a two-dimensional scanning platform.
图2是所述平面探测器的结构示意图。Fig. 2 is a schematic structural diagram of the planar detector.
图3是三维相控重建算法的原理示意图。Fig. 3 is a schematic diagram of the principle of the three-dimensional phase-controlled reconstruction algorithm.
图4是实施例2中利用实施例1的装置与方法所进行横向截面光声成像实验图，其中(a)为对应于图中下方实物照片的二维横向重建图像；(b)为相吸收体的三维重建图像。Fig. 4 is a photoacoustic imaging experiment diagram of a transverse section carried out by using the device and method of Example 1 in Example 2, wherein (a) is a two-dimensional transverse reconstruction image corresponding to the real photo at the bottom of the figure; (b) is phase absorption 3D reconstructed image of the body.
图5是实施例2利用实施例1的装置与方法所进行纵向截面光声成像实验图，其中(a)为对应于图中下方实物照片的二维纵向重建图像；(b)为吸收体的三维重建图像。Fig. 5 is a photoacoustic imaging experiment diagram of a longitudinal section in Example 2 using the device and method of Example 1, wherein (a) is a two-dimensional longitudinal reconstruction image corresponding to the real photo at the bottom of the figure; (b) is the image of the absorber 3D reconstructed image.
具体实施方式Detailed ways
下面结合具体的实例与附图对本发明作进一步详细的叙述，但本发明的实施方法灵活，不仅仅限于此例所述的具体操作方式。The present invention will be further described in detail below in conjunction with specific examples and accompanying drawings, but the implementation method of the present invention is flexible and is not limited to the specific operation mode described in this example.
实施例1 本发明的装置与图像算法Embodiment 1 The device and image algorithm of the present invention
图1为本发明整套成像装置的原理结构示意图，此装置由四大部分组成，分别是光声信号发生器件、光声信号采集与传输装备、控制探头平移设备、计算机组件；四个部分依次电气连接。其中光声信号发生器件的激光器1-1为Nd:YAG泵浦的OPO激光器(Vibrant 532 I，Opotek，Carlsbad，Calif.)，输出激光波长为690～960nm，脉宽为10ns，重复频率是10Hz。OPO发出脉冲激光束，两次经过反射镜2-1以45°的入射角被分束镜2-2分成一束反射光，一束透射光；两束能量相等的光束分别经过对称且垂直放置的反射镜2-1后就都以45°的入射角照射样品2-3产生光声信号，在两束光入射前分别加一个扩束镜2-4是为了增大光声的激发区域而且激光所经历的路线均处在一个平面内。位于样品上方的面阵探测器3-1由64个压电的方形阵元构成，以8×8的形式均匀分布在1cm2的矩形区域内，阵元的尺寸和阵元之间的间距都是0.984mm，每个探测阵元的信号接收角度为14°。探测器的主频是7.5MHz，带宽是60％。Fig. 1 is the schematic diagram of the principle structure of the whole set of imaging device of the present invention, and this device is made up of four major parts, is respectively photoacoustic signal generation device, photoacoustic signal acquisition and transmission equipment, control probe translation equipment, computer component; connect. The laser 1-1 of the photoacoustic signal generating device is an Nd:YAG pumped OPO laser (Vibrant 532 I, Opotek, Carlsbad, Calif.), the output laser wavelength is 690-960nm, the pulse width is 10ns, and the repetition frequency is 10Hz . The OPO emits a pulsed laser beam, which passes through the mirror 2-1 twice and is divided into a beam of reflected light and a beam of transmitted light by the beam splitter 2-2 at an incident angle of 45°; two beams of equal energy are respectively placed symmetrically and vertically After the reflection mirror 2-1, the sample 2-3 is irradiated with an incident angle of 45° to generate a photoacoustic signal, and a beam expander 2-4 is added before the two beams of light are incident to increase the photoacoustic excitation area and The routes experienced by the laser are all in one plane. The area array detector 3-1 located above the sample is composed of 64 piezoelectric square array elements, which are evenly distributed in a rectangular area of 1cm2 in the form of 8×8. The size of the array elements and the spacing between the array elements are both It is 0.984mm, and the signal receiving angle of each detection array element is 14°. The main frequency of the detector is 7.5MHz, and the bandwidth is 60%.
图2是面阵探测器的结构示意图，外黑线框为探测器的整体外尺寸形状，内黑线框表示64个压电阵元分布的区域；矩形的阵元是按8×8的方式规则排列的，红点所标记的阵元是用来接地的并不接收信号。面阵探测器收集通过水2-5耦合的信号，经由64通道并行采集系统4-1的预处理直接通过USB数据线传输到计算机5-1中，最后利用MATLAB结合三维相控算法来重建三维图像。并行采集设备是用LABVIEW软件控制的64通道实时采集电路，探测器上的每一个阵元通过电缆线与采集电路的通道一一对应，每路信号通过采集电路完成模拟信号到数字信号的转化，以及信号的前置放大处理。如果想成像不同位置的光吸收结构只需改变光路，然后通过自编的LABVIEW控制软件控制步进电机6-1带动二维扫描平台6-2使得探测器移动到光声源上方。装置变动简单，操作方便。Figure 2 is a schematic diagram of the structure of the area array detector. The outer black line frame is the overall size and shape of the detector, and the inner black line frame indicates the area where 64 piezoelectric array elements are distributed; the rectangular array elements are in the form of 8×8 Arranged regularly, the array elements marked by red dots are used for grounding and not receiving signals. The area array detector collects the signals coupled by water 2-5, and transmits the preprocessing of the 64-channel parallel acquisition system 4-1 to the computer 5-1 directly through the USB data line, and finally uses MATLAB combined with the 3D phase control algorithm to reconstruct the 3D image. The parallel acquisition device is a 64-channel real-time acquisition circuit controlled by LABVIEW software. Each array element on the detector corresponds to the channel of the acquisition circuit through a cable, and each signal is converted from an analog signal to a digital signal through the acquisition circuit. And signal pre-amplification processing. If you want to image light-absorbing structures at different positions, you only need to change the optical path, and then control the stepper motor 6-1 to drive the two-dimensional scanning platform 6-2 through the self-edited LABVIEW control software to move the detector to the top of the photoacoustic source. The device is easy to change and easy to operate.
图3是本发明图像重建算法的原理示意图。首先64个压电阵元同时接收处于它们接收范围内的空间光声信号，因此每一个阵元均可以采集不同半径扫描弧面上的信号，通过记录每个阵元接收光声脉冲的时间值以及测量光声信号在介质中的传播速度就能分辨出不同检测深度上的信号分布情况，然后将这些信号值按照对应的投影半径投影到原来所处的空间位置，那么最终那些具有吸收结构的部分就通过光声信号值的相干叠加而在图像中凸显出来。Fig. 3 is a schematic diagram of the principle of the image reconstruction algorithm of the present invention. Firstly, 64 piezoelectric array elements receive the spatial photoacoustic signal within their receiving range at the same time, so each array element can collect signals on the scanning arc surface with different radii, by recording the time value of each array element receiving the photoacoustic pulse And by measuring the propagation velocity of the photoacoustic signal in the medium, the signal distribution at different detection depths can be distinguished, and then these signal values are projected to the original spatial position according to the corresponding projection radius, then finally those with absorbing structures Parts are highlighted in the image by coherent addition of photoacoustic signal values.
实施例2 应用实施例1的装置与方法实现模拟样品的横向截面光声成像。Example 2 The device and method of Example 1 were used to realize the photoacoustic imaging of the transverse section of the simulated sample.
首先用13％的明胶，12.5％的牛奶，74.5％的水混合在一起做成一个方形的模型，然后选取两根长度约为6mm，尺寸100um的头发丝埋入到5mm深的模型内，两根头发丝相对于平面探测器3-1水平平行放置，相距大概4mm，同时把探测器3-1位置固定好位于样品2-3上方并且调整探测器3-1到头发丝平面的距离为4mm。实验中OPO激光器1-1的工作频率为15Hz，脉宽10ns，波长为532nm。脉冲激光束通过装置上的光路后均匀的覆盖到两根头发丝上，激发产生的光声信号被平面探测器3-1接收，经过并行采集系统4-1的前置滤波及预防大后，经由USB数据线传输到计算机5-1，最终用三维相控算法在MATLAB软件上实现图像重组。图4(a)与(b)分别给出了对应于右下样品照片的横向重建层析切片以及三维重建图像。两幅图像无论在位置与大小上均能与样品照片很好的吻合。可以看出本发明方法与装置能够得到较好分辨率和对比度的光声横向层析图像。First, mix 13% gelatin, 12.5% milk, and 74.5% water to make a square model, and then select two hairs with a length of about 6mm and a size of 100um and bury them in the model with a depth of 5mm. The root hair is placed horizontally and parallel to the plane detector 3-1, with a distance of about 4mm. At the same time, the position of the detector 3-1 is fixed above the sample 2-3 and the distance between the detector 3-1 and the hair plane is adjusted to 4mm. . In the experiment, the operating frequency of OPO laser 1-1 is 15Hz, the pulse width is 10ns, and the wavelength is 532nm. The pulsed laser beam passes through the optical path of the device and evenly covers the two hairs. The photoacoustic signal generated by the excitation is received by the planar detector 3-1, and after the pre-filtering and prevention of the parallel acquisition system 4-1, It is transmitted to the computer 5-1 via the USB data line, and finally the image reconstruction is realized on the MATLAB software by using the three-dimensional phase control algorithm. Figure 4(a) and (b) show the transverse reconstructed tomographic slice and the three-dimensional reconstructed image corresponding to the lower right sample photo, respectively. The two images can be well matched with the sample photo in terms of position and size. It can be seen that the method and device of the present invention can obtain photoacoustic transverse tomography images with better resolution and contrast.
实施例3 应用实施例1的装置与方法实现模拟样品的纵向截面光声成像。Example 3 The device and method of Example 1 were used to realize the photoacoustic imaging of the longitudinal section of the simulated sample.
与实施例2类似，同样将两根与实施例2大小，尺寸相同的头发丝放置在同样组成成分的模型内，两根头发丝互相平行放置在垂直于探测器3-1的某一平面内，相距同样是4mm。探测器3-1到两根头发的距离分别是28mm与32mm。实验的激光器1-1工作在15Hz频率，脉宽为10ns，波长532nm。经分束后的两束激光均匀照射在不同深度上的样品2-3，产生的光声信号通过探测器3-1接收，并行采集系统4-1预处理后，被传输到计算机5-1完成图像重建。图5(a)与(b)分别给出了对应于右下样品照片的纵向重建层析切片以及三维重建图像。从实验的结果可以得出以下结论：本发明与装置能够重建出不同深度上样品的光声层析图像，能够得到不同断层处的信息，拥有快速纵向层析成像能力。Similar to Example 2, two hair strands of the same size and size as in Example 2 are also placed in a model with the same composition, and the two hair strands are placed parallel to each other in a certain plane perpendicular to the detector 3-1 , the same distance is 4mm. The distances from the detector 3-1 to the two hairs are 28mm and 32mm respectively. The experimental laser 1-1 works at a frequency of 15 Hz, a pulse width of 10 ns, and a wavelength of 532 nm. After splitting, the two laser beams uniformly irradiate the sample 2-3 at different depths, and the generated photoacoustic signal is received by the detector 3-1, preprocessed by the parallel acquisition system 4-1, and then transmitted to the computer 5-1 Complete image reconstruction. Figure 5(a) and (b) show the longitudinal reconstructed tomographic slice and the three-dimensional reconstructed image corresponding to the bottom right sample photo, respectively. The following conclusions can be drawn from the experimental results: the invention and the device can reconstruct photoacoustic tomographic images of samples at different depths, can obtain information at different faults, and have fast longitudinal tomographic imaging capabilities.
上述实施例为本发明较佳的实施方式，但本发明的实施方式并不受上述实施例的限制，其他的任何未背离本发明的精神实质与原理下所作的改变、修饰、替代、组合、简化，均应为等效的置换方式，都包含在本发明的保护范围之内。The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201010139117.XACN101813672B (en) | 2010-03-30 | 2010-03-30 | Rapid three-dimensional photoacoustic imaging system based on ultrasonic plane array detector and method thereof |
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201010139117.XACN101813672B (en) | 2010-03-30 | 2010-03-30 | Rapid three-dimensional photoacoustic imaging system based on ultrasonic plane array detector and method thereof |
| Publication Number | Publication Date |
|---|---|
| CN101813672A CN101813672A (en) | 2010-08-25 |
| CN101813672Btrue CN101813672B (en) | 2014-12-10 |
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201010139117.XAExpired - Fee RelatedCN101813672B (en) | 2010-03-30 | 2010-03-30 | Rapid three-dimensional photoacoustic imaging system based on ultrasonic plane array detector and method thereof |
| Country | Link |
|---|---|
| CN (1) | CN101813672B (en) |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023187238A1 (en)* | 2022-04-01 | 2023-10-05 | Universitat Politècnica De València | Optical device, system and method for producing photoacoustic images using homogenised beams from pulsed light sources |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3173781B8 (en)* | 2015-11-25 | 2024-06-12 | Xarion Laser Acoustics GmbH | Airborne ultrasound testing system for a test object |
| CN102279226A (en)* | 2011-07-01 | 2011-12-14 | 烟台富润实业有限公司 | Contact-type laser ultrasonic probe device |
| JP2013027481A (en)* | 2011-07-27 | 2013-02-07 | Fujifilm Corp | Photoacoustic imaging system and apparatus, and probe unit used therefor |
| CN102488494B (en)* | 2011-11-16 | 2013-09-25 | 华中科技大学 | Totally internal reflection type photo-acoustic microscopic imaging system and method |
| CN102579073B (en)* | 2011-12-01 | 2013-09-11 | 华中科技大学 | Self-adaptive image reconstruction method for photo-acoustic microscopic imaging |
| CN102512207A (en)* | 2011-12-13 | 2012-06-27 | 苏州生物医学工程技术研究所 | B-ultrasonic probe type photoacoustic imaging mammary gland scanner and scanning method thereof |
| CN102608036B (en)* | 2012-03-20 | 2014-09-10 | 中北大学 | Three-dimensional opto-acoustic imaging system based on acoustic lens and sensor array and method |
| CN105050485B (en)* | 2012-08-14 | 2017-08-18 | 皇家飞利浦有限公司 | Compact lasers and efficient pulse delivery for photoacoustic imaging |
| CN106691377A (en)* | 2016-12-15 | 2017-05-24 | 哈尔滨工业大学（威海） | Photoacoustic microimaging adaptive scanning system and method |
| CN107157445B (en)* | 2017-05-04 | 2019-11-12 | 中国科学院深圳先进技术研究院 | A device for detecting the exit angle deviation between the light field and the sound field of an endoscopic probe |
| CN107462638A (en)* | 2017-08-10 | 2017-12-12 | 兰州理工大学 | The defects of signal is swept based on ultrasonic A three-dimensional rebuilding method |
| CN109199332B (en)* | 2018-09-28 | 2021-12-07 | 同济大学 | Photoacoustic and ultrasonic bimodal endoscopic imaging device and method based on light reflection |
| CN110333293B (en)* | 2019-08-12 | 2021-08-24 | 河海大学常州校区 | A Method for Exciting and Detecting Concrete Defects by Square Grid Phased Ultrasonic Array |
| CN110455719A (en)* | 2019-08-16 | 2019-11-15 | 中国科学技术大学 | Three-dimensional photoacoustic imaging system and method |
| CN113777045B (en)* | 2020-06-10 | 2022-10-18 | 复旦大学 | Super-resolution functional photoacoustic imaging method based on single-particle multilateral localization tracking |
| CN111948147B (en)* | 2020-09-25 | 2023-07-25 | 广东工业大学 | A full-field ultrasonic microscope imaging system and method without blind spots |
| CN112971728A (en)* | 2021-03-17 | 2021-06-18 | 华中科技大学同济医学院附属协和医院 | Photoacoustic imaging method and system for mammary gland |
| CN115657326B (en)* | 2022-09-30 | 2025-06-13 | 北京理工大学 | A reconfigurable laser ultrasonic phased array device and method |
| CN118603895B (en)* | 2024-08-01 | 2024-11-19 | 西安电子科技大学 | A photoacoustic imaging device and method based on multi-wavelength LED excitation |
| CN118655090B (en)* | 2024-08-16 | 2025-02-07 | 之江实验室 | A method, device, storage medium and electronic device for photoacoustic imaging demixing |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1792335A (en)* | 2005-12-16 | 2006-06-28 | 华南师范大学 | Photoacoustic imaging and chromatographic imaging method based on acoustic lens and apparatus thereof |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6999174B2 (en)* | 2001-11-13 | 2006-02-14 | Battelle Memorial Institute | Photoacoustic spectroscopy sample array vessels and photoacoustic spectroscopy methods for using the same |
| CN1247158C (en)* | 2003-02-26 | 2006-03-29 | 华南师范大学 | Method and device for biological tissue photoacoustic tomography |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1792335A (en)* | 2005-12-16 | 2006-06-28 | 华南师范大学 | Photoacoustic imaging and chromatographic imaging method based on acoustic lens and apparatus thereof |
| Title |
|---|
| 曾吕明.光声和热声成像系统及图像重建算法研究.《中国优秀硕士学位论文全文数据库》.2007,第2章-第5章.* |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023187238A1 (en)* | 2022-04-01 | 2023-10-05 | Universitat Politècnica De València | Optical device, system and method for producing photoacoustic images using homogenised beams from pulsed light sources |
| Publication number | Publication date |
|---|---|
| CN101813672A (en) | 2010-08-25 |
| Publication | Publication Date | Title |
|---|---|---|
| CN101813672B (en) | Rapid three-dimensional photoacoustic imaging system based on ultrasonic plane array detector and method thereof | |
| Fast photoacoustic imaging system based on 320-element linear transducer array | ||
| US9220415B2 (en) | Systems and methods for frequency-domain photoacoustic phased array imaging | |
| US10241199B2 (en) | Ultrasonic/photoacoustic imaging devices and methods | |
| Singh et al. | Photoacoustic-guided focused ultrasound (PAFUSion) for identifying reflection artifacts in photoacoustic imaging | |
| EP2553425B1 (en) | Photoacoustic imaging apparatus and photoacoustic imaging method | |
| CN102727259B (en) | Photoacoustic tomography device and method based on limited-angle scanning | |
| CN102944521B (en) | Non-contact photoacoustic and optical coherence tomography dual-imaging device and detection method thereof | |
| CN102525550B (en) | Measuring apparatus | |
| CN104706323B (en) | High-speed large-view-field multi-spectral photoacoustic imaging method and device | |
| CN107713990A (en) | A kind of thermoacoustic, optoacoustic, ultrasonic three mode tumor of breast detection means and method | |
| Telenkov et al. | Fourier-domain biophotoacoustic subsurface depth selective amplitude and phase imaging of turbid phantoms and biological tissue | |
| JP2015507947A5 (en) | ||
| JP5675390B2 (en) | measuring device | |
| JP2000517414A (en) | Method and apparatus for three-dimensional ultrasonic microscopy using short pulse excitation and three-dimensional ultrasonic microscope used therein | |
| CN100446730C (en) | Photoacoustic imaging and tomographic imaging method and device based on acoustic lens | |
| JP2011212254A (en) | Imaging device and method of the same | |
| CN106560160A (en) | Object Information Acquiring Apparatus And Control Method Thereof | |
| JP4422626B2 (en) | Biological imaging device | |
| JP6742734B2 (en) | Object information acquisition apparatus and signal processing method | |
| JP2017047177A (en) | Subject information acquiring apparatus and control method for subject information acquiring apparatus | |
| CN101336832A (en) | Pulsed photoacoustic scanning soft tissue imaging method and device | |
| CN103313649A (en) | Measuring apparatus | |
| Beard et al. | 2D line-scan photoacoustic imaging of absorbers in a scattering tissue phantom | |
| Thompson et al. | Laser-induced synthetic aperture ultrasound imaging |
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee | Granted publication date:20141210 |