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Optical imaging of biological tissue using speckle patterns of ultrasound-modulated light

使用超声调制光的散斑图案对生物组织进行光学成像

基本信息

批准号：
13680921
负责人：
KUDO Nobuki
金额：
$ 2.3万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13680921/
关键词：
ultrasound optical modulation optical imaging spacial resolution pulsed ultrasound pulsed light speckle weak light detection

项目摘要

To improve spatial resolution of optical imaging of biological tissue, a new method using speckle patterns of ultrasound-modulated light was proposed. Results of experimental evaluations of the proposed method are summarized as follows.1. A proposed method and an experimental system : To detect temporal variations of optical speckle patterns in ultrasound frequency, we used a conventional CCD still camera and introduced a principle of a strobe scope, that is, the shutter of the CCD still camera is open and the object observed is illuminated by pulsed light synchronized with exposed ultrasound. The experimental system used the cooled CCD camera of 16-bits contrast resolution. A pulsed laser diode (power =600 mW, pulse width = 0.1 ns) was used as the illumination light source, and a focused ultrasound transducer of 1 MHz in center frequency was used as the ultrasound source.2. Transmission Imaging : One-dimensional transmission imaging of a breast tumor phantom was carried out. The light … More source, the phantom, and the CCD camera were placed in line and speckle patterns generated by transmitted light was used for imaging. An agar phantom (Thickness = 35 mm, μs'=0.5 mm^<-1>) was used as the phantom, and an absorbing object (10x10x10 mm^3) mimicking a breast tumor (μa= 0.048 mm^<-1>, μs'= 0.5 mm^<-1>) was buried at the center of the phantom. A profile of the absorbing object imaged by the proposed method is steeper than that of a conventional imaging result, indicating that the spatial resolution of optical imaging was improved by detecting the ultrasound modulated light.3. Reflection Imaging : One-dimensional imaging was also tried using speckle patterns generated by reflected light. In this experiment, the light source and the CCD camera were placed at the same side of the phantom. The illumination beam entered the phantom at an angle of approximately 65 degrees, and an image of the speckle pattern generated on the same surface of the phantom was taken using a CCD camera placed in front of the phantom. Also in this case, spatial resolution was improved using the proposed method, and it was shown that this method has wide applicability.4. Improvement of the system : In the above experiments, it took about 10 hours to measure a one dimensional profile because the pulse width of the light was needlessly small. A high-power light source (power =20 W, pulse width = 50 ns) was used, and measurement time was greatly reduced without S/N drop. Less

为了提高生物组织光学成像的空间分辨率，提出了一种利用超声调制光散斑图的新方法。实验结果的评价所提出的方法总结如下. 1.所提出的方法和实验系统：为了检测超声频率下的光学散斑图案的时间变化，我们使用传统的CCD静态相机，并介绍了一个频闪范围的原理，即，CCD静态相机的快门是开放的，被观察的对象是由与曝光的超声同步的脉冲光照明。实验系统采用16位对比度分辨率的冷态CCD摄像机。采用脉冲激光二极管（功率600 mW，脉宽0.1 ns）作为照明光源，中心频率为1 MHz的聚焦超声换能器作为超声源.透射成像：对乳腺肿瘤体模进行一维透射成像。光 ...更多信息光源、体模和CCD照相机成一直线放置，并且由透射光产生的散斑图案用于成像。使用琼脂体模（厚度= 35 mm，μ s '= 0.5 mm^<-1>）作为体模，并在体模中心埋入模拟乳腺肿瘤（μa= 0.048 mm^，μ s'= 0.5 mm^）的吸收物体（10 × 10 × 10 mm ^3<-1><-1>）。利用该方法成像的吸收体轮廓比常规成像结果陡峭，表明超声调制光的探测提高了光学成像的空间分辨率.反射成像：还尝试使用由反射光产生的散斑图案进行一维成像。在该实验中，光源和CCD相机被放置在体模的同一侧。照明光束以大约65度的角度进入体模，并且使用放置在体模前面的CCD相机拍摄在体模的相同表面上生成的散斑图案的图像。同时，该方法提高了空间分辨率，具有广泛的适用性.系统的改进：在上述实验中，由于光的脉冲宽度不必要地小，因此花费大约10个小时来测量一维轮廓。使用高功率光源（功率=20 W，脉冲宽度= 50 ns），并且测量时间大大缩短而没有S/N下降。少