Name: wideband optical detector of ultrasound for medical imaging applications
Uploaded: 2014-05-11T15:00:00
Description: Watch this Scientific Journal Video about Wideband Optical Detector of Ultrasound for Medical Imaging Applications at JoVE.com

DR确认来自德国研究基金会（DFG）的研究资助（RA1分之1848）和欧洲研究委员会开始给予扶持。 VN确认来自欧洲研究委员会高级研究员奖的财政支持，以及BMBF的创新医学奖。

1，光声的π光纤光栅探测器的表征<ol><li>准备一个微小的球体悬浮在琼脂： <ol><li>混合琼脂粉末（按重量计1.3％），在玻璃烧杯中的蒸馏水。使用热板磁搅拌器装置来加热溶液接近沸腾的温度和溶解的琼脂粉末，直到溶液变成气泡的清晰和自由。可替换地，琼脂溶液可以用常规的微波与手动使用的玻璃搅拌器搅拌下进行加热。倒入热溶液倒入一个塑料模具， 如注射器，其顶端切掉。 </li><...

<ol>
	<li>Hunt, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasound+transducers+for+pulse-echo+medical+imaging.">Ultrasound transducers for pulse-echo medical imaging.</a> IEEE Transactions on Biomedical Engineering. 30, 453-481 (1983).</li><li>Razansky, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multispectral+opto-acoustic+tomography+of+deep-seated+fluorescent+proteins+in+vivo.">Multispectral opto-acoustic tomography of deep-seated fluorescent proteins in vivo.</a> Nature Photon. 3, 412-417 (2009).</li><li>Ntziachristos, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Going+deeper+than+microscopy:+the+optical+imaging+frontier+in+biology.">Going deeper than microscopy: the optical imaging frontier in biology.</a> Nature Methods. 7, 603-614 (2010).</li><li>Wang, L. H., Hu, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photoacoustic+tomography:+In+vivo+imaging+from+organelles+to+organs.">Photoacoustic tomography: In vivo imaging from organelles to organs.</a> Science. 23, 1458-1462 (2012).</li><li>Sethuraman, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photoacoustic+imaging+using+an+IVUS+imaging+catheter.">Photoacoustic imaging using an IVUS imaging catheter.</a> IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. 54, 978-986 (2007).</li><li>Rosenthal, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optoacoustic+methods+for+frequency+calibration+of+ultrasonic+sensors.">Optoacoustic methods for frequency calibration of ultrasonic sensors.</a> IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. 58, 316-326 (2011).</li><li>Rosenthal, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-sensitivity+compact+ultrasonic+detector+based+on+a+pi-phase-shifted+fiber+Bragg+grating.">High-sensitivity compact ultrasonic detector based on a pi-phase-shifted fiber Bragg grating.</a> Optics Letters. 36, 1833-1835 (2011).</li><li>Beard, P. C., Mills, T. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extrinsic+optical+fibre+ultrasound+sensor+using+a+thin+polymer+film+as+a+low+finesse+Fabry-Perot+interferometer.">Extrinsic optical fibre ultrasound sensor using a thin polymer film as a low finesse Fabry-Perot interferometer.</a> Applied Optics. 35, 663-675 (1996).</li><li>Xiong Pernice, W. H. P., Tang, C., X, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+Q+micro-ring+resonators+fabricated+from+polycrystalline+aluminum+nitride+films+for+near+infrared+and+visible+photonics.">High Q micro-ring resonators fabricated from polycrystalline aluminum nitride films for near infrared and visible photonics.</a> Optics Express. 20, 12261-12269 (2012).</li><li>Zhang, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Backward-mode+multiwavelength+photoacoustic+scanner+using+a+planar+Fabry-Perot+polymer+film+ultrasound+sensor+for+high-resolution+three-dimensional+imaging+of+biological+tissues.">Backward-mode multiwavelength photoacoustic scanner using a planar Fabry-Perot polymer film ultrasound sensor for high-resolution three-dimensional imaging of biological tissues.</a> Applied Optics. 47, 561-577 (2008).</li><li>Gr&#252;n, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+photoacoustic+imaging+using+fiber-based+line+detectors.">Three-dimensional photoacoustic imaging using fiber-based line detectors.</a> Journal of Biomedical Optics. 15, 021306-02 (2010).</li><li>Avino, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Musical+instrument+pickup+based+on+a+laser+locked+to+an+optical+fiber+resonator.">Musical instrument pickup based on a laser locked to an optical fiber resonator.</a> Optics. Express. 19, 25057-25065 (2011).</li><li>Rosenthal, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wideband+optical+sensing+using+pulse+interferometry.">Wideband optical sensing using pulse interferometry.</a> Optics Express. 20, 19016-19029 (2012).</li><li>Rosenthal, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wideband+fiber-interferometer+stabilization+with+variable+phase.">Wideband fiber-interferometer stabilization with variable phase.</a> IEEE Photonics Technology Letters. 24, 1499-1501 (2012).</li><li>Rosenthal, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatial+characterization+of+the+response+of+a+silica+optical+fiber+to+wideband+ultrasound.">Spatial characterization of the response of a silica optical fiber to wideband ultrasound.</a> Optics Letters. 37, 15-3174 (2012).</li><li>Rosenthal, A., Razansky, D., Ntziachristos, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Model-based+optoacoustic+inversion+with+arbitrary-shape+detectors.">Model-based optoacoustic inversion with arbitrary-shape detectors.</a> Medical Physics. 38, 4285-4295 (2011).</li></ol>

总之，超声检测一个新的光学方法被引入，这是基于一种π-FBG和脉冲干涉的结合。该技术特别适合于由于传感元件，可实现几乎任意物体的照明图案的透明性光声成像应用。与此相反，基于标准的压电超声探测器是不透明的，从而阻止某些光路的成像物体，导致笨重的成像设置。因此，开发了光学检测器可以促进光声技术的微型化和其临床翻译。 传感元件的物理和机械性能?...

超声波探测器在许多成像应用中发挥了关键作用。按照惯例，超声波是由压电换能器，其转换压力波成电压信号检测1。在光声成像，超声是通过热膨胀过程中通过用高功率调制的光照射2-6生成的对象。虽然压电换能器是选择在光声应用的方法中，它们的使用往往阻碍了小型化的，主要是因为小型化的压电换能器通常具有低灵敏度。另外，由于压电振子是光学不透明的，它们可能会严重的光传递到成象物体干扰，限制了可以使用的成像结构的可能性。光被反向散射从物​​体到传感器也可以限制正确检测超声波和成像系统的设计复杂化，由于光诱导学与寄生虫病IC信号在换能器7。 超声的光学检测器已被确认为，提供在光声成像的场景8-12许多好处一个可能替代压电换能器：它们通常是透明的，通常可以小型化而不损失灵敏度。光学检测器的工作原理是干涉检测在光学介质由于超声波的存在而产生的微小变形。通常，光学谐振器中使用，以提高检测的灵敏度由在扰动介质俘获光的持续时间延长，从而增加了变形的光信号的相位的影响。在这种情况下，光学检测方案是基于监测变化的谐振波长，这直接关系到结构变形的谐振器。最常见的是，使用窄线宽连续波（CW）技术，其中CW激光器被调谐到日Ë共振波长。小偏移的共振波长的变化的共振范围内的激光的波长的相对位置，这样就造成在发送/激光反射光，从而可以容易地监测的强度变化。然而，如果共振位移太强， 例如由于大的变化，压力，温度，或振动，共振可能转向完全远离激光的波长，有效饱和检测器13。 脉冲干涉14提供了一个解决方案，信号饱和的限制，使易挥发的环境条件下的超声检测。而相比之下，窄线宽CW计划，脉冲干涉采用宽带脉冲光源来照亮谐振器。在这种情况下，谐振器作为一个带通滤波器，仅发送那些对应于它的谐振频率的波长，而共振转移一个再通过测量在谐振器的输出， 例如 ，通过使用马赫-曾德尔干涉仪锁定到正交14,15的光信号在波长变化进行检测。自动复位电路用于立即恢复干涉仪的工作点在其丢失，由于在环境条件极端变化的情况。由于源的相对广泛的带宽，谐振波长停留在照射范围内，即使在强干扰，即使在恶劣的环境条件下实现稳定的检测器操作。审讯， 即光脉冲，使用相干光源的利于低噪声检测。 在我们的实验中所采用的相应脉冲干涉测量系统示于图1。用于问诊的脉冲激光产生90飞秒脉冲在100 MHz与60毫瓦，光谱宽度超过100的输出功率的重复率纳米。光学滤波器具有约0.4纳米的FWHM光谱宽度和被调谐到谐振频率。以下的过滤器，光放大器被用于补偿在滤波的显著损失。额外的过滤是在扩增阶段之后施加，以减少从放大器放大的自发辐射。在我们的实验中所使用的谐振器是一个π相移的光纤布拉格光栅（π-FBG）8，由TeraXion公司公司制造特别是用于超声波检测的医疗应用中，π-光纤光栅有被全光纤组件的好处，因此健壮和小。 图2示出光纤在这项工作中使用的尺寸和15 MHz的小型化的血管内超声（IVUS）压电换能器之间的比较。一些替代共振为基础的检测方法，如在平面制作波导的微环谐振器，需要耦合纤维在组件的输入和输出，要么导致更脆弱的设备或妨碍小型化。与此相反，π-光纤光栅是在光纤组件，并且不需要额外的光纤耦合。在π-光纤光栅的共振是由它们的中心的圆周率相移创建;光被捕获围绕以上，比光栅本身的长度大大短纤维的一部分的pI相移。在我们的实验中，π-FBG为4毫米，κ=2毫米耦合系数的长度-1，并且其灵敏度分布不均匀地沿其长度，用灵敏度指数从光栅的中心减小与κ的速率。灵敏度分布（SD）的全宽度半最大值（FWHM）为约350微米。光栅的共振宽度是由两个其长度，并根据下面的等式其耦合系数确定： <img alt="式（1）" fo:content-width="1.5in" src=“/ files/ftp_upload/50847/50847eq1.jpg”宽度=“150”/&gt;（1） 其中λ为谐振波长，n EFF的是引导在光纤8的模的有效折射率。 评估π-FBG检测器是否是适当的成像应用中，它的空间依赖反应需要在很宽的频带内进行测量。然而，这个任务是当使用传统的声学技术极具挑战性。因此，我们采用一种光声方法超声检测鉴定16在一个黑暗的显微球体嵌入透明的琼脂作为一种光声点源。在我们的实验中，微观球体的直径为约100微米，被照射高功率的纳秒光脉冲的重复频率为10Hz，约8毫微秒脉冲持续时间，和200毫瓦的平均功率。沉积在微观sph的光能量ERES产生由于光声效应的宽带超声信号。该πFBG检测器相对转化为微观球体，得到其空间相关的声学响应。 图3示出了光声实验的示意图。通常，该技术可以被用来表征不同种类的超声波探测器。

<table border="0" cellpadding="0" cellspacing="0" width="573">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="43">
			<td height="43" style="height:43px;width:216px;">&#960;-FBG</td>
			<td style="width:71px;">Teraxion Inc.</td>
			<td style="width:119px;"></td>
			<td style="width:167px;">&#160;Custom made device</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:216px;">microscopic sphere</td>
			<td style="width:71px;">Cospheric LLC</td>
			<td style="width:119px;">BKPMS 90-106um- 10g</td>
			<td style="width:167px;">100 &#181;m polyethylene microsphere</td>
		</tr>
		<tr height="64">
			<td height="64" style="height:64px;width:216px;">Femto-second pulse laser used for interrogation&#160;</td>
			<td style="width:71px;">Menlo Systems GmbH</td>
			<td style="width:119px;">T-Light Femtosecond Laser</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="64">
			<td height="64" style="height:64px;width:216px;">Optical filter</td>
			<td style="width:71px;">Optoplex Corporation</td>
			<td style="width:119px;">2-Port Optical Tunable Filter (50 GHz)</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="64">
			<td height="64" style="height:64px;width:216px;">Optical amplifier</td>
			<td style="width:71px;">Amonics</td>
			<td style="width:119px;">AEDFA-PM-PA-35-B-FC</td>
			<td style="width:167px;">Benchtop 35dB Gain Pre Amp Polarization Maintaining EDFA&#160;</td>
		</tr>
		<tr height="232">
			<td height="232" style="height:232px;width:216px;">50/50 coupler</td>
			<td style="width:71px;">OZ-Optics</td>
			<td style="width:119px;">FUSED-22-1550-8/125-50/50-3S3S3S3S-3-0.5-PM</td>
			<td style="width:167px;">Fused 2x2 fiber splitter with 0.5 meter long, 3mm OD PVC jacketed 1550nm 8/125&#956; PM fiber 
			pigtails, 50/50 split ratio in the slow axes of PM fibers and with super FC/PC connectors on all 
			ports.</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:216px;">Fiber holder</td>
			<td style="width:71px;">Thorlabs</td>
			<td style="width:119px;">T711/M-250</td>
			<td style="width:167px;">Metric, Post-Mountable Fiber Clamp, 250 &#181;m&#160;</td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:216px;">Agar for microbiology</td>
			<td style="width:71px;">Sigma Aldrich</td>
			<td style="width:119px;">05039-500G</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="64">
			<td height="64" style="height:64px;width:216px;">Nano-second pulse laser used for generating the optoacoustic signals</td>
			<td style="width:71px;">Opotek</td>
			<td style="width:119px;">VIBRANT Arrow 532 type I</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="43">
			<td height="43" style="height:43px;width:216px;">Graphite rod</td>
			<td style="width:71px;">&#160;Faber-Castell</td>
			<td style="width:119px;">120700</td>
			<td style="width:167px;">Faber-Castell Pencil Leads - 0.7 mm</td>
		</tr>
	</tbody>
</table>

wideband optical detector of ultrasound for medical imaging applications

超声的光学传感器是一种很有前途的替代压电技术，因为已经在光声成像领域，最近证实。在医疗应用中，光学感测技术的主要限制之一是其易感性的环境条件， 例如变化的压力和温度，这可能饱和的检测。此外，临床环境中经常施加在传感器上的大小和鲁棒性严格限制。在这项工作中，脉冲干涉和基于光纤的光学感测的组合被证明为超声检测。脉冲干涉使读出系统中的环境条件快速变化的存在的鲁棒性能，而使用的全光纤技术导致具有高要求的医疗应用中，例如血管内成像相容的机械柔性传感元件。为了实现短的传感器的长度，一的π相移的光纤布喇格光栅时，它充当谐振器捕集光超过350微米的有效长度。实现高​​带宽，该传感器用于检测侧向超声波的，这是在圆周成像几何形状，如血管内成像高度有利的。一种光声成像的设置是用来确定该传感器用于在不同位置的声源点的响应。

图4a和4b分别显示了从微观球体在从纤维从π-FBG的中心3的偏移的距离为1毫米的信号和它们的相应的光谱。的偏移量给出在z方向上，如在图3中所描绘，显然，所述的光检测器的灵敏度，以高频超声（F&gt; 6兆赫）是各向异性的，并且是最高时的π-FBG的中心是微观球体正上方。尽管二氧化硅纤维和水之间的高的声阻抗失配，没有明显的共振频率高于6MHz的观察，?...

Watch this Scientific Journal Video about Wideband Optical Detector of Ultrasound for Medical Imaging Applications at JoVE.com

Wideband Optical Detector of Ultrasound for Medical Imaging Applications

光学检测超声检查是不切实际的许多成像方案，因为它往往需要稳定的环境条件。我们展示了一个光学技术的超声波传感动荡的环境与适宜光声成像的小型化和灵敏度水平的限制情况下， 如血管内应用。

宽带超声医疗成像应用，光学检测仪

Optical sensors of ultrasound are a promising alternative to piezoelectric techniques, as has been recently demonstrated in the field of optoacoustic ...

Research

JoVE Journal

Bioengineering

Three-dimensional Optical-resolution Photoacoustic Microscopy

三维光学分辨率的光声显微镜

Optical microscopy, providing valuable insights at the cellular and organelle levels, has been widely recognized as an enabling biomedical technology. As ...

科研

生物工程

Optical Frequency Domain Imaging of Ex vivo Pulmonary Resection Specimens: Obtaining One to One Image to Histopathology Correlation

Optical Frequency Domain Imaging of Ex vivo Pulmonary Resection Specimens: Obtaining One to One Image to Histopathology Correlation

光频域成像<em&gt;体外</em肺切除标本：获得一对一的图像病理组织学的相关性

Lung cancer is the leading cause of cancer-related deaths1. Squamous cell and small cell cancers typically arise in association with the conducting ...

Preparation of Mica Supported Lipid Bilayers for High Resolution Optical Microscopy Imaging

支持的脂双层云母制备的高分辨率光学显微成像

Supported lipid bilayers (SLBs) are widely used as a model for studying membrane properties (phase separation, clustering, dynamics) and its interaction ...

Biofunctionalized Prussian Blue Nanoparticles for Multimodal Molecular Imaging Applications

Biofunctionalized普鲁士蓝纳米粒子多式联运分子成像应用

Multimodal, molecular imaging allows the visualization of biological processes at cellular, subcellular, and molecular-level resolutions using multiple, ...

Real-time Monitoring of High Intensity Focused Ultrasound (HIFU) Ablation of In Vitro Canine Livers Using Harmonic Motion Imaging for Focused Ultrasound (HMIFU)

Real-time Monitoring of High Intensity Focused Ultrasound HIFU Ablation of In Vitro Canine Livers Using Harmonic Motion Imaging for Focused Ultrasound HMIFU

高强度的实时监控聚焦超声（HIFU）消融<em&gt;体外</em&gt;使用谐运动成像的聚焦超声犬肝脏（HMIFU）

Harmonic Motion Imaging for Focused Ultrasound (HMIFU) is a technique that can perform and monitor high-intensity focused ultrasound (HIFU) ablation. An ...

Computed Tomography and Optical Imaging of Osteogenesis-angiogenesis Coupling to Assess Integration of Cranial Bone Autografts and Allografts

计算机断层扫描和成骨血管生成耦合光学成像评估头盖骨自体移植和移植物的整合

A major parameter determining the success of a bone-grafting procedure is vascularization of the area surrounding the graft. We hypothesized that ...

High-throughput Identification of Bacteria Repellent Polymers for Medical Devices

医疗器械细菌高通量鉴定驱蚊聚合物

Medical devices are often associated with hospital-acquired infections, which place enormous strain on patients and the healthcare system as well as ...

Medical-grade Sterilizable Target for Fluid-immersed Fetoscope Optical Distortion Calibration

对于流体沉浸胎儿镜的光学畸变校正医用灭菌目标

We have developed a calibration target for use with fluid-immersed endoscopes within the context of the GIFT-Surg (Guided Instrumentation for Fetal ...

Long-term Live Imaging Device for Improved Experimental Manipulation of Zebrafish Larvae

改善斑马鱼幼虫实验操作的长期活体成像装置

The zebrafish larva is an important model organism for both developmental biology and wound healing. Further, the zebrafish larva is a valuable system for ...

Optical Imaging of Isolated Murine Ventricular Myocytes

分离的月毛心室肌细胞的光学成像

The ability to isolate adult cardiac myocytes has permitted researchers to study a variety of cardiac pathologies at the single cell level. While advances ...