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><li>撒上少量的琼脂溶液微观领域，并等待，直到溶液完全凝固。通过推动柱塞采取固体琼脂幻影出模具。 </li><li>观看立体显微镜下的幽灵剪一小块琼脂其中包含一个单一的微观领域。 </li><li>重复步骤1.1.1和增加TØ琼脂溶液中的单个微观领域的固体琼脂片。 </li><li>凝固后，切显微镜，使得显微球体靠近幻影表面下的琼脂幻影。 </li></ol></li><li>光声测量<ol><li>用两个V形槽光纤支架紧紧地保持在纤维上的π-FBG的两侧，和夹持器连接到一个三维（XYZ）翻译计算机操作的阶段。确保纤维被浸没，使超声波的传播。 </li><li>查找所述感测的π-FBG元件的受照射的纤维的不同部位与高功率纳秒脉冲激光光束的大致位置。光吸收涂层的，然而弱，会产生一个信号，当在π-FBG进行照明。 </li><li>将琼脂包埋微观球体直接指向下方的π-FBG。微观领域应该是可见的，肉眼。 </li><li>使用翻译阶段，在平行的平面进行的π-FBG的2D扫描到地面寻找到从微观领域的信号是最强的，其对应的时间延迟最短的位置。 </li><li>执行最后一次调整照明以提供最大功率的微观领域。 </li><li>使用翻译阶段执行π-FBG的三维扫描，并在每个位置上记录信号。 </li><li>取得的超声波探测器的空间相关的频率响应，执行对所记录的时域超声信号的傅立叶变换。 </li></ol></li></ol>鲁棒性和π-FBG探测器的性能灵敏度的2。估计<ol><li>用两个V形槽光纤支架紧紧地保持在纤维上的π-FBG的两侧，并浸没π-FBG。 </li><li>将深色板或石墨棒茁壮面对的π-FBG，照亮它的机智h时高功率纳秒脉冲激光束，形成强大的声场。 </li><li>将水泵水箱内，打开它，以建立在环境条件的快速变化。 </li><li>来估计系统的鲁棒性，测量与所述锁定电路的输出变成开和关。当没有进行锁定，因此不可能精确地检测到的超声信号。 </li><li>关闭水泵关闭。 </li><li>为了估计灵敏度的利益由于源的高相干性，具有低相干光源更换宽带脉冲激光，重复声学测量。当低相干源用于预期的下降超过一个数量级的灵敏度。 </li></ol>

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作者宣称，他们有没有竞争的财务权益。

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。

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	<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 ...

wideband-optical-detector-ultrasound-for-medical-imaging

Research

JoVE Journal

Bioengineering

10.7K 次观看.  Technical University of Munich and Helmholtz Center Munich. 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。 

视频: Wideband Optical Detector of Ultrasound for Medical Imaging Applications

Three-dimensional Optical-resolution Photoacoustic Microscopy

Optical microscopy, providing valuable insights at the cellular and organelle levels, has been widely recognized as an enabling biomedical technology. As the mainstays of in vivo three-dimensional (3-D) optical microscopy, single-/multi-photon fluorescence microscopy and optical coherence tomography (OCT) have demonstrated their extraordinary sensitivities to fluorescence and optical scattering contrasts, respectively. However, the optical absorption contrast of biological tissues, which encodes essential physiological/pathological information, has not yet been assessable. 
The emergence of biomedical photoacoustics has led to a new branch of optical microscopy optical-resolution photoacoustic microscopy (OR-PAM)1, where the optical irradiation is focused to the diffraction limit to achieve cellular1 or even subcellular2 level lateral resolution. As a valuable complement to existing optical microscopy technologies, OR-PAM brings in at least two novelties. First and most importantly, OR-PAM detects optical absorption contrasts with extraordinary sensitivity (i.e., 100%). Combining OR-PAM with fluorescence microscopy3 or with optical-scattering-based OCT4 (or with both) provides comprehensive optical properties of biological tissues. Second, OR-PAM encodes optical absorption into acoustic waves, in contrast to the pure optical processes in fluorescence microscopy and OCT, and provides background-free detection. The acoustic detection in OR-PAM mitigates the impacts of optical scattering on signal degradation and naturally eliminates possible interferences (i.e., crosstalks) between excitation and detection, which is a common problem in fluorescence microscopy due to the overlap between the excitation and fluorescence spectra. 
Unique for optical absorption imaging, OR-PAM has demonstrated broad biomedical applications since its invention, including, but not limited to, neurology5, 6, ophthalmology7, 8, vascular biology9, and dermatology10. In this video, we teach the system configuration and alignment of OR-PAM as well as the experimental procedures for in vivo functional microvascular imaging.

Optical-resolution photoacoustic microscopy (OR-PAM) is an emerging technology capable of imaging optical absorption contrasts in vivo with cellular resolution and sensitivity. Here, we provide a visualized instruction on the experimental protocols of OR-PAM, including system configuration, system alignment, typical in vivo experimental procedures, and functional imaging schemes.

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

Lung cancer is the leading cause of cancer-related deaths1. Squamous cell and small cell cancers typically arise in association with the conducting airways, whereas adenocarcinomas are typically more peripheral in location. Lung malignancy detection early in the disease process may be difficult due to several limitations: radiological resolution, bronchoscopic limitations in evaluating tissue underlying the airway mucosa and identifying early pathologic changes, and small sample size and/or incomplete sampling in histology biopsies. High resolution imaging modalities, such as optical frequency domain imaging (OFDI), provide non-destructive, large area 3-dimensional views of tissue microstructure to depths approaching 2 mm in real time (Figure 1)2-6. OFDI has been utilized in a variety of applications, including evaluation of coronary artery atherosclerosis6,7 and esophageal intestinal metaplasia and dysplasia6,8-10.
Bronchoscopic OCT/OFDI has been demonstrated as a safe in vivo imaging tool for evaluating the pulmonary airways11-23 (Animation). OCT has been assessed in pulmonary airways16,23 and parenchyma17,22 of animal models and in vivo human airway14,15. OCT imaging of normal airway has demonstrated visualization of airway layering and alveolar attachments, and evaluation of dysplastic lesions has been found useful in distinguishing grades of dysplasia in the bronchial mucosa11,12,20,21. OFDI imaging of bronchial mucosa has been demonstrated in a short bronchial segment (0.8 cm)18. Additionally, volumetric OFDI spanning multiple airway generations in swine and human pulmonary airways in vivo has been described19. Endobronchial OCT/OFDI is typically performed using thin, flexible catheters, which are compatible with standard bronchoscopic access ports. Additionally, OCT and OFDI needle-based probes have recently been developed, which may be used to image regions of the lung beyond the airway wall or pleural surface17.
While OCT/OFDI has been utilized and demonstrated as feasible for in vivo pulmonary imaging, no studies with precisely matched one-to-one OFDI:histology have been performed. Therefore, specific imaging criteria for various pulmonary pathologies have yet to be developed. Histopathological counterparts obtained in vivo consist of only small biopsy fragments, which are difficult to correlate with large OFDI datasets. Additionally, they do not provide the comprehensive histology needed for registration with large volume OFDI. As a result, specific imaging features of pulmonary pathology cannot be developed in the in vivo setting. Precisely matched, one-to-one OFDI and histology correlation is vital to accurately evaluate features seen in OFDI against histology as a gold standard in order to derive specific image interpretation criteria for pulmonary neoplasms and other pulmonary pathologies. Once specific imaging criteria have been developed and validated ex vivo with matched one-to-one histology, the criteria may then be applied to in vivo imaging studies. Here, we present a method for precise, one to one correlation between high resolution optical imaging and histology in ex vivo lung resection specimens. Throughout this manuscript, we describe the techniques used to match OFDI images to histology. However, this method is not specific to OFDI and can be used to obtain histology-registered images for any optical imaging technique. We performed airway centered OFDI with a specialized custom built bronchoscopic 2.4 French (0.8 mm diameter) catheter. Tissue samples were marked with tissue dye, visible in both OFDI and histology. Careful orientation procedures were used to precisely correlate imaging and histological sampling locations. The techniques outlined in this manuscript were used to conduct the first demonstration of volumetric OFDI with precise correlation to tissue-based diagnosis for evaluating pulmonary pathology24. This straightforward, effective technique may be extended to other tissue types to provide precise imaging to histology correlation needed to determine fine imaging features of both normal and diseased tissues.

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

A method to image ex vivo pulmonary resection specimens with optical frequency domain imaging (OFDI) and obtain precise correlation to histology is described, which is essential to developing specific OFDI interpretation criteria for pulmonary pathology. This method is applicable to other tissue types and imaging techniques to obtain precise imaging to histology correlation for accurate image interpretation and assessment. Imaging criteria established with this technique would then be applicable to image assessment in future in vivo studies.

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

Supported lipid bilayers (SLBs) are widely used as a model for studying membrane properties (phase separation, clustering, dynamics) and its interaction with other compounds, such as drugs or peptides. However SLB characteristics differ depending on the support used. 
Commonly used techniques for SLB imaging and measurements are single molecule fluorescence microscopy, FCS and atomic force microscopy (AFM). Because most optical imaging studies are carried out on a glass support, while AFM requires an extremely flat surface (generally mica), results from these techniques cannot be compared directly, since the charge and smoothness properties of these materials strongly influence diffusion. Unfortunately, the high level of manual dexterity required for the cutting and gluing thin slices of mica to the glass slide presents a hurdle to routine use of mica for SLB preparation. Although this would be the method of choice, such prepared mica surfaces often end up being uneven (wavy) and difficult to image, especially with small working distance, high numerical aperture lenses. Here we present a simple and reproducible method for preparing thin, flat mica surfaces for lipid vesicle deposition and SLB preparation. Additionally, our custom made chamber requires only very small volumes of vesicles for SLB formation. The overall procedure results in the efficient, simple and inexpensive production of high quality lipid bilayer surfaces that are directly comparable to those used in AFM studies.

We present a method of preparing mica supported lipid bilayers for high resolution microscopy. Mica is transparent and flat on an atomic scale, but rarely used in imaging because of handling difficulties; our preparation results in even deposition of the mica sheet, and reduces the material used in bilayer preparation.

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

Multimodal, molecular imaging allows the visualization of biological processes at cellular, subcellular, and molecular-level resolutions using multiple, complementary imaging techniques. These imaging agents facilitate the real-time assessment of pathways and mechanisms in vivo, which enhance both diagnostic and therapeutic efficacy. This article presents the protocol for the synthesis of biofunctionalized Prussian blue nanoparticles (PB NPs) - a novel class of agents for use in multimodal, molecular imaging applications. The imaging modalities incorporated in the nanoparticles, fluorescence imaging and magnetic resonance imaging (MRI), have complementary features. The PB NPs possess a core-shell design where gadolinium and manganese ions incorporated within the interstitial spaces of the PB lattice generate MRI contrast, both in T1 and T2-weighted sequences. The PB NPs are coated with fluorescent avidin using electrostatic self-assembly, which enables fluorescence imaging. The avidin-coated nanoparticles are modified with biotinylated ligands that confer molecular targeting capabilities to the nanoparticles. The stability and toxicity of the nanoparticles are measured, as well as their MRI relaxivities. The multimodal, molecular imaging capabilities of these biofunctionalized PB NPs are then demonstrated by using them for fluorescence imaging and molecular MRI in vitro.

This protocol describes the synthesis of biofunctionalized Prussian blue nanoparticles and their use as multimodal, molecular imaging agents. The nanoparticles have a core-shell design where gadolinium or manganese ions within the nanoparticle core generate MRI contrast. The biofunctional shell contains fluorophores for fluorescence imaging and targeting ligands for molecular targeting.

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)

Harmonic Motion Imaging for Focused Ultrasound (HMIFU) is a technique that can perform and monitor high-intensity focused ultrasound (HIFU) ablation. An oscillatory motion is generated at the focus of a 93-element and 4.5 MHz center frequency HIFU transducer by applying a 25 Hz amplitude-modulated signal using a function generator. A 64-element and 2.5 MHz imaging transducer with 68kPa peak pressure is confocally placed at the center of the HIFU transducer to acquire the radio-frequency (RF) channel data. In this protocol, real-time monitoring of thermal ablation using HIFU with an acoustic power of 7 W on canine livers in vitro is described. HIFU treatment is applied on the tissue during 2 min and the ablated region is imaged in real-time using diverging or plane wave imaging up to 1,000 frames/second. The matrix of RF channel data is multiplied by a sparse matrix for image reconstruction. The reconstructed field of view is of 90&#176; for diverging wave and 20 mm for plane wave imaging and the data are sampled at 80 MHz. The reconstruction is performed on a Graphical Processing Unit (GPU) in order to image in real-time at a 4.5 display frame rate. 1-D normalized cross-correlation of the reconstructed RF data is used to estimate axial displacements in the focal region. The magnitude of the peak-to-peak displacement at the focal depth decreases during the thermal ablation which denotes stiffening of the tissue due to the formation of a lesion. The displacement signal-to-noise ratio (SNRd) at the focal area for plane wave was 1.4 times higher than for diverging wave showing that plane wave imaging appears to produce better displacement maps quality for HMIFU than diverging wave imaging.

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

This article describes real-time monitoring of HIFU ablation in canine liver with high frame rate ultrasound imaging using diverging and plane wave imaging. Harmonic Motion Imaging for Focused Ultrasound is used to image the decrease of acoustic radiation force induced displacement in the ablated region.

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

A major parameter determining the success of a bone-grafting procedure is vascularization of the area surrounding the graft. We hypothesized that implantation of a bone autograft would induce greater bone regeneration by abundant blood vessel formation. To investigate the effect of the graft on neovascularization at the defect site, we developed a micro&#8211;computed tomography (&#181;CT) approach to characterize newly forming blood vessels, which involves systemic perfusion of the animal with a polymerizing contrast agent. This method enables detailed vascular analysis of an organ in its entirety. Additionally, blood perfusion was assessed using fluorescence imaging (FLI) of a blood-borne fluorescent agent. Bone formation was quantified by FLI using a hydroxyapatite-targeted probe and &#181;CT analysis. Stem cell recruitment was monitored by bioluminescence imaging (BLI) of transgenic mice that express luciferase under the control of the osteocalcin promoter. Here we describe and demonstrate preparation of the allograft, calvarial defect surgery, &#181;CT scanning protocols for the neovascularization study and bone formation analysis (including the in vivo perfusion of contrast agent), and the protocol for data analysis.
The 3D high-resolution analysis of vasculature demonstrated significantly greater angiogenesis in animals with implanted autografts, especially with respect to arteriole formation. Accordingly, blood perfusion was significantly higher in the autograft group by the 7th day after surgery. We observed superior bone mineralization and measured greater bone formation in animals that received autografts. Autograft implantation induced resident stem cell recruitment to the graft-host bone suture, where the cells differentiated into bone-forming cells between the 7th and 10th postoperative day. This finding means that enhanced bone formation may be attributed to the augmented vascular feeding that characterizes autograft implantation. The methods depicted may serve as an optimal tool to study bone regeneration in terms of tightly bounded bone formation and neovascularization.

Implantation of autologous and allogeneic bone grafts constitute accepted approaches to treat major craniofacial bone loss. Yet the effect of graft composition on the interplay among neovascularization, cell differentiation and bone formation is unclear. We present a multimodal imaging protocol aimed to elucidate the angiogenesis-osteogenesis interdependence at the graft proximity.

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

Medical devices are often associated with hospital-acquired infections, which place enormous strain on patients and the healthcare system as well as contributing to antimicrobial resistance. One possible avenue for the reduction of device-associated infections is the identification of bacteria-repellent polymer coatings for these devices, which would prevent bacterial binding at the initial attachment step. A method for the identification of such repellent polymers, based on the parallel screening of hundreds of polymers using a microarray, is described here. This high-throughput method resulted in the identification of a range of promising polymers that resisted binding of various clinically relevant bacterial species individually and also as multi-species communities. One polymer, PA13 (poly(methylmethacrylate-co-dimethylacrylamide)), demonstrated significant reduction in attachment of a number of hospital isolates when coated onto two commercially available central venous catheters. The method described could be applied to identify polymers for a wide range of applications in which modification of bacterial attachment is important.

A high-throughput microarray method for the identification of polymers which reduce bacterial surface binding on medical devices is described.

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

We have developed a calibration target for use with fluid-immersed endoscopes within the context of the GIFT-Surg (Guided Instrumentation for Fetal Therapy and Surgery) project. One of the aims of this project is to engineer novel, real-time image processing methods for intra-operative use in the treatment of congenital birth defects, such as spina bifida and the twin-to-twin transfusion syndrome. The developed target allows for the sterility-preserving optical distortion calibration of endoscopes within a few minutes. Good optical distortion calibration and compensation are important for mitigating undesirable effects like radial distortions, which not only hamper accurate imaging using existing endoscopic technology during fetal surgery, but also make acquired images less suitable for potentially very useful image computing applications, like real-time mosaicing. In this paper proposes a novel fabrication method to create an affordable, sterilizable calibration target suitable for use in a clinical setup. This method involves etching a calibration pattern by laser cutting a sandblasted stainless steel sheet. This target was validated using the camera calibration module provided by OpenCV, a state-of-the-art software library popular in the computer vision community.

This article describes the design and development of a sterilizable custom camera optical distortion calibration target for the peri-operative, fluid-immersed calibration of endoscopes during endoscopic interventions.

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

The zebrafish larva is an important model organism for both developmental biology and wound healing. Further, the zebrafish larva is a valuable system for live high-resolution microscopic imaging of dynamic biological phenomena in space and time with cellular resolution. However, the traditional method of agarose encapsulation for live imaging can impede larval development and tissue regrowth. Therefore, this manuscript describes the zWEDGI (zebrafish Wounding and Entrapment Device for Growth and Imaging), which was designed and fabricated as a functionally compartmentalized device to orient larvae for high-resolution microscopy while permitting caudal fin transection within the device and subsequent unrestrained tail development and re-growth. This device allows for wounding and long-term imaging while maintaining viability. Given that the zWEDGI mold is 3D printed, the customizability of its geometries make it easily modified for diverse zebrafish imaging applications. Furthermore, the zWEDGI offers numerous benefits, such as access to the larva during experimentation for wounding or for the application of reagents, paralleled orientation of multiple larvae for streamlined imaging, and reusability of the device.

This manuscript describes the zWEDGI (zebrafish Wounding and Entrapment Device for Growth and Imaging), which is a compartmentalized device designed to orient and restrain zebrafish larvae. The design permits tail transection and long-term collection of high-resolution fluorescent microscopy images of wound healing and regeneration.

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

The ability to isolate adult cardiac myocytes has permitted researchers to study a variety of cardiac pathologies at the single cell level. While advances in calcium sensitive dyes have permitted the robust optical recording of single cell calcium dynamics, recording of robust transmembrane optical voltage signals has remained difficult. Arguably, this is because of the low single to noise ratio, phototoxicity, and photobleaching of traditional potentiometric dyes. Therefore, single cell voltage measurements have long been confined to the patch clamp technique which while the gold standard, is technically demanding and low throughput. However, with the development of novel potentiometric dyes, large, fast optical responses to changes in voltage can be obtained with little to no phototoxicity and photobleaching. This protocol describes in detail how to isolate adult murine myocytes which can be used for cellular shortening, calcium, and optical voltage measurements. Specifically, the protocol describes how to use a ratiometric calcium dye, a single-excitation calcium dye, and a single excitation voltage dye. This approach can be used to assess the cardiotoxicity and arrhythmogenicity of various chemical agents. While phototoxicity is still an issue at the single cell level, methodology is discussed on how to reduce it.

We present the methodology for the isolation of murine myocytes and how to obtain voltage or calcium traces simultaneously with sarcomere shortening traces using fluorescence photometry with simultaneous digital cell geometry measurements.

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 ...