我们谨向瑞典国防部 (信息) 和灾难医学和创伤治疗中心 (KMC) 的林雪平工作人员表示谢意, 感谢他们的亲切支持。

这里描述的研究遵循了当地的道德准则, 并得到了林雪平地区伦理审查委员会的批准 (许可证编号 2015/99-31)。
1. 知情同意和甄别
<ol><li>获得有关问题的知情同意。</li>
	<li>根据包含/排除标准进行筛选。 注: 纳入标准为: (一) 健康成人 > 18 岁, (二) 能够理解书面和口头信息, (三) 提供口头和书面同意。排除标准是: (一) 无法或不愿意提供知情同意, (二) 持续的皮肤状况, (iii) 心血管疾病, (iv) 可干扰血管功能的药物。口服避孕药是允许的。如果主题使用口服避孕药, 应在主题的协议文件中注明, (五) 前额无疤痕和无擦伤皮肤, (六) 在试验开始前2小时不摄入咖啡因或烟草, (vii) 没有剧烈的体力活动至少 2 h pr开始测试。</li>
</ol>2. 驯化和设备设置
<ol><li>在测试开始前, 让测试对象适应至少20分钟的仰卧位。 注: 主题和设备的正确定位显示在补充图1中。</li>
	<li>
使用指定的软件和数码相机设置毛细管填充测试的相机记录 (见材料表)。
	<ol>
<li>将 USB 电缆连接到照相机和计算机, 并将摄像机设置调整为视频模式。</li>
		<li>打开摄像机, 确保它连接到计算机。</li>
		<li>启动远程控制的照相机软件 (请参见材料表)。</li>
		<li>关闭环境光源, 将计算机屏幕从测量区域中关闭。</li>
	</ol>
</li>
</ol>3. 数据采集
<ol><li>单击 "生命视图" (Sic) 按钮, 然后按 "开始"。</li>
	<li>在 "视频" 模式和 "TiVi" 模式之间切换, 方法是单击单选按钮 (这不会影响录制, 只有屏幕显示)。确保在摄像机和计算机屏幕上显示主体前额的实时视频流。</li>
	<li>调整相机的高度约15厘米直接以上的主体的额头。</li>
	<li>确保照相机的焦点设置为 "AF" (自动对焦)。</li>
	<li>要求受试者保持他/她的头仍然在测试期间和克制谈话。在测试过程中, 请告知这个问题, 让他/她的眼睛闭上是 OK 的, 说: "拜托, 把你的头放在这个枕头上, 保持你的头部在测试期间。请不要在20秒内说, 测试将持续。如果你觉得光线太亮, 你可能会一直闭着眼睛。</li>
	<li>录制时请勿移动相机。</li>
	<li>在 "生命视图" 窗口中找到并单击 "HD 记录" 以开始二十年代的连续录制. 注意记录的持续时间 (秒), 可以在摄像头显示的时候看到;记录的前5秒是获得正常的前额毛细血管血浓度。</li>
	<li>在基线记录的5秒结束时, 对 5 s 的测量区域应用一个牢固的烫漂压力. 使用食指和前额之间的塑料茶匙来进行压力平衡和温度隔离。</li>
	<li>释放压力, 并迅速从测量区域撤回考官的手指和塑料茶匙。</li>
	<li>继续录制另一个十年代, 以捕获随后的充血响应。</li>
	<li>通过单击 "生命视图" 窗口中的 "停止" 停止录制。</li>
	<li>录制停止后, 将打开一个窗口, 用于保存和命名文件 (以。选择视频的文件夹和名称。在将视频下载到计算机上的指定文件夹时, 请勿将照相机与计算机断开。</li>
</ol>4. 数据分析
<ol><li>使用专用的分析软件继续执行图像分析和曲线构造 (请参见材料表)。</li>
	<li>通过双击桌面图标启动分析软件。</li>
	<li>软件启动后, 在主屏幕上选择 "影片页面"。</li>
	<li>在 "影片页面" 窗口中, 单击 "加载影片"。等待软件上传和分析电影。这可能需要几分钟时间, 这取决于视频文件的大小。</li>
	<li>一旦电影的上传和分析完成, 点击 "另存为图像", 等待软件分析视频。 注意: 这将自动在包含视频序列的计算机上创建一个新文件夹, 并将其分为单独的 jpeg 图像。</li>
	<li>将视频分割成单独的 jpeg 图像后, 在主屏幕窗口中查找并选择 "裁剪图像页面"。</li>
	<li>在 "裁剪图像页面" 中, 单击 "第一张照片", 然后导航到包含视频中的 jpeg 照片的文件夹, 然后选择要分析的第一张照片;该软件将自动选择该批的以下照片。</li>
	<li>单击 "编辑" 菜单, 并为感兴趣的区域选择圆形或矩形标记。</li>
	<li>在 "选择照片" 窗口中, 找到 "实际照片" 框, 并键入在批中的第一张照片的名称, 调查员的手指完全从测量区域收回。要查找此照片, 请查看包含来自视频的单个照片的文件夹。</li>
	<li>通过单击并按住鼠标左键并在位于脱皮区域边框内的照片窗口中绘制圆形或矩形, 选择感兴趣的区域。所选的感兴趣区域将自动应用于批次的所有照片。</li>
	<li>单击 "文件" 菜单, 选择 "保存 ROI" 以保存所选区域的位置, 以备将来参考。</li>
	<li>单击 "曲线跟踪器" 按钮, 等待软件分析感兴趣的区域。</li>
	<li>一旦 "曲线跟踪器" 窗口打开, 在测试期间所选的感兴趣区域的红血球浓度变化将显示为曲线。通过单击不同的单选按钮, 可以更改屏幕上的演示文稿。这不会影响原始数据。</li>
	<li>单击 "导出数据" 并保存原始数据记录以进行进一步分析。</li>
	<li>在原始数据记录中, 导航到名为 "平均强度 TiVi 值" 的列。该列旁边的 "图像编号"、"总时间" 和 "毛细管重填时间" 在 1 s、0 s 和 0 s 之间生成三新列, 分别为 1 s、0.02 s 和 0.02 s 的增量。 注: "毛细管重填时间" 与随后对热烫压力释放的反应时间相关, 并以平均值表示第一张照片, 调查人员的手指完全从测量区域收回。</li>
	<li>删除基线和毛细管重填时间之间的值, 因为这些数值只包含由研究者的食指和塑料茶匙在烫漂过程中产生的噪音。</li>
	<li>计算基准测量的平均值 (记录的前5秒)。</li>
	<li>查找等于或超过计算平均值基线值的第一个值, 并记下 "毛细管填充时间" 列中的时间。此时间点表示 "返回到基线1的时间"。</li>
	<li>找到压力释放后产生的值的最高平均强度值, 并记下 "毛细管重填时间" 列中的时间点。这个时间点代表了 "高峰时间"。</li>
	<li>查找小于或等于基线测量的计算平均值的第二个值, 并记下 "毛细管重填时间" 列中的时间点。此时间点表示 "返回到基线2的时间"。</li>
</ol>

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WheelsBridge AB 的财务支持没有参与研究的进行。作者约翰是受雇于约特兰郡议会, 但有一个版税协议与 WheelsBridge AB。资深作家综合教育有一个全职的学术职位, 但也有限的参与 WheelsBridge AB。

为了使系统得到最佳的结果, 必须控制环境因素造成的变化。所有的环境光必须关闭。照相机必须与测量区域垂直对齐。为了保证一个恒定的测量区域, 对象不应该移动或谈话在测量期间。出于同样的原因, 相机最好安装在一个立场, 以避免移动和保持一个恒定的距离测量区域。测试对象应避免咖啡因的17, 烟草18, 和硬练习19至少两个 h 之前的测试和休息20分钟之前开始测量, 因为这些因素是已知的影响微循环。测试对象应在仰卧位与测量部位的心脏水平, 以避免位置再分配的血容量。应监测室温和皮肤温度, 因为已知温度会影响填充时间20,21。
还有其他的生物工程替代肉眼评估和提出的技术, 可用于测量 CR 测试。这些技术中的大多数在皮肤上反射后使用偏振或偏振光的变化22,23,24 。其他技术使用摄像机25测量皮肤颜色的变化, 这可能与临床情况非常相似。此外, 通过将表面温度与真皮血流量的变化关联起来, 可以实现血液流动的间接测量26。这些替代技术旨在测量皮肤的有限面积或仅用于一个解剖站点 (如, 手指)23,24,25。 有了这个新的系统, 就可以在视频和静止摄影之间切换, 并捕获一个大的区域, 例如一个肢体甚至整个身体, 如果有必要, 具有高的时间和空间分辨率。因此, 我们认为, 这是一个有吸引力的技术, 进一步生理和病理生理学特征的毛细血管填充反应。
应该注意的是, 在这里描述和使用的相机系统和皮肤漂烫演习是为研究目的而设计的, 尚未进行优化, 以供临床使用。为了完全可用作为一种监测危重病人的方法, 该系统需要小型化和简化。理想的情况下, 相机系统应与设备, 提供标准化的烫漂压力, 并提出一个生理相关的读数瞬间。虽然我们正处于研究 CR 反应的基本生理学的早期阶段, 但我们相信, 这些挑战中的大部分可以通过技术发展来管理。

危重病人的评估和分诊集中在经典生命体征血压 (BP)、心率 (HR)、呼吸率 (RR)、氧饱和度和体温1。这些参数的变化在循环恶化过程中显得相对较晚。例如, 在出血, 血压下降将不会发生, 直到血液损失变得中度到严重的2, HR 增加也可以是一个不敏感的和不标记3。
毛细管重填试验 (CR 测试) 可以提供早期的循环崩溃的征兆, 因为重填时间在重要征兆之前被相信改变, 并且临床出现冷, 阴湿黏的和斑驳的皮肤1,4,5. 毛细管填充试验通常是由应用, 然后释放一个坚定的漂白压力的皮肤与时间 (以秒计) 的血液返回到脱皮区域。根据指导原则, 重填应该在2秒内发生, 在5秒的牢固的压力 (例如, 由医生的手指) 在正常健康仰卧患者6。测试的基本原理是, 较慢的填充时间将表明皮肤灌注不良, 可能是由许多关键事件之一, 如脓毒症, 失血, 急性心力衰竭, 或体温过低造成的。
目前, 在执行 CR 测试的艺术方法的状态上没有达成一致意见6,7,8,9,10。有争议的问题包括缺乏标准化的实际漂烫机动和依赖主观 (即, 裸眼) 评估的填充端点7,9,11。此外, 有迹象表明, 性别影响 CR 时间12,13。温度, 环境和皮肤, 是已知的影响毛细管填充时间, 但在何种程度上是不清楚的。最后, 使用不同的测量点, 外围或中央, 可能是一个进一步的原因变化的结果, 在这方面的研究很少14,15。
在目前的工作中, 我们使用了一个光学生物工程系统, 以记录血液的返回过程和随后的充血反应, 在 CR 试验中看到。该系统利用漫反射极化光谱学, 更详细地量化和描述, 比可能的肉眼, 毛细管填充的时间和过程。该系统包括一个标准的数码相机, 装有一个外部的光环与92白色 led, 和专门开发的软件。镜头和两个偏振过滤器, 连接正交在前面的 led, 阻挡光, 已直接反映在皮肤表面, 只允许光已成为偏的组织, 以达到相机。这就产生了一个 "亚表皮" 的组织图像, 深度约0.5 毫米。图像分为其颜色平面, 并计算每个像素的红色和绿色内容, 生成一个对应于红细胞组织浓度的值16。在视频模式下, 系统的时间分辨率为0.02 秒。

<table><tbody><tr><td>TiVi701 Camera</td><td>WheelsBridge AB</td><td>TiVi701 Camera, version 1.5.1</td><td>Software</td></tr><tr><td>TiVi700</td><td>WheelsBridge AB</td><td>TiVi700 Analysis, version 1.2.9</td><td>Software</td></tr><tr><td>Canon EOS 700D</td><td>Canon U.S.A., inc.</td><td>Canon EOS 700D</td><td>Digital SLR Camera</td></tr><tr><td>Camera stand</td><td>Manfrotto</td><td>681B</td><td>Modified camera stand to hold the digital camera in position</td></tr><tr><td>Camera stand</td><td>Disa Denmark</td><td>9020B</td><td>Modified camera stand to hold the digital camera in position</td></tr></tbody></table>

diffuse reflectance spectroscopy: getting the capillary refill test under one's thumb

毛细管重填试验在1947年引入, 以帮助估计危重病患者的循环系统状况。通常情况下, 在正常健康的仰卧位患者释放5的牢固压力 (如, 由医生的手指) 后, 应在2秒内发生重填。较慢的填充时间表示皮肤灌注不良, 这可能是由于败血症、失血、灌注和体温过低造成的。自其介绍以来, 该试验的临床效用已被争论。倡导者指出它的可行性和简单性, 并声称它可以显示血管状态的变化早于生命体征的变化, 如心率。另一方面, 批评家强调, 在测试中缺乏标准化, 肉眼评估的高度主观性, 以及测试对周围环境因素的敏感性, 明显降低了临床价值。本工作的目的是详细描述重新灌装事件的过程, 并提出了潜在的更客观和准确的终点值的毛细管填充试验使用漫极化光谱学。

拍摄的毛细管重填过程产生了大量的数据不可能获得肉眼评估。我们建议在这里新的端点, 以进一步提高 CR 测试的可用性, 作为早期的指标恶化的循环状态。我们称这些端点为: "基线"、"血零" (或 ")"、"返回基线1的时间" (或 "tRtB1")、"时间到峰值" 或 "Tpk"。"基线" 值是通过计算在 5 s 基线测量期间获得的所有值的平均值来获得的。"血零" 是指在压力释放后立即从脱皮区域的第一个图像中获得的平均值。"tRtB1" 的定义是在烫漂压力释放后的时间, 以秒为单位, 直到漂白面积的值等于或高于 "基线" 值。"Tpk" 对应于记录最高值的时间。图 1显示了从一个健康的男性志愿者在室温下进行的测试的常规照片和彩色编码图像的选择。图 2显示了来自与上面所述相同测试的毛细管填充测试的代表性曲线。所描述的测试中的测量时间为3分钟, 在临床情况下不适用, 但说明在该值返回到基线值之前需要多长的时间。
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/56737/56737fig1.jpg"> 图 1: 在健康志愿者中, 毛细管填充反应.在一个健康的男性志愿者的额头上进行的毛细血管重填试验 (上排) 和相关的彩色编码图像 (下一行) 的选择。(a) 显示前压力的应用, 在压力释放后立即漂白的区域 (B) 和充血反应 (C)。<a href="//cloudflare-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/56737/56737fig1large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/56737/56737fig2.jpg"> 图 2: 毛细管填充响应的详细轮廓和建议的端点.该图显示了毛细血管重灌的过程, 随着时间的推移红细胞浓度的变化, 在一个健康的男性志愿者的额头和新的建议端点的分析产生的漫反射光谱视频。"基线" 值是通过计算在 5 s 基线测量期间获得的所有值的平均值来获得的。"血零" 是指在压力释放后立即从脱皮区域的第一个图像中获得的平均值。"tRtB1" 的定义是在烫漂压力释放后的时间, 以秒为单位, 直到漂白面积的值等于或高于 "基线" 值。"Tpk" 对应于记录最高值的时间。<a href="//cloudflare-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/56737/56737fig2large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
补充图 1: 测量设置和主题的定位.该图显示了一个有代表性的设置, 用于测量一个静止的、健康的主体前额上的 CR 响应。偏振滤波器和导光环安装在标准数码相机上。相机是连接到一个稳定的三脚架与一个灵活的, 3 路可调头, 允许正确的定位。通过使用标准的塑料茶匙, 在 5 s 的测量区域施加了牢固的压力。请注意, 环境光线应变暗, 以避免干扰测量。<a href="https://cloudflare-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/56737/Supplemental_figure_1.tif">请单击此处下载此文件.</a>

Watch this Scientific Journal Video about Diffuse Reflectance Spectroscopy: Getting the Capillary Refill Test Under One's Thumb at JoVE.com

Diffuse Reflectance Spectroscopy: Getting the Capillary Refill Test Under One's Thumb

该协议描述了如何使用漫极化光谱学可以提高临床效用的毛细管填充试验。我们建议使用漫反射光谱视频和新的信息端点对健康志愿者毛细血管充盈的过程进行更详细的分析。

漫反射光谱分析: 在拇指下进行毛细管填充试验

The capillary refill test was introduced in 1947 to help estimate circulatory status in critically ill patients. Guidelines commonly state that refill ...

diffuse-reflectance-spectroscopy-getting-capillary-refill-test-under

Universidad San Sebastian

Research

Education

JoVE Core

JoVE Journal

Medical-Surgical Nursing

Neuroscience

Unit 1

An Overview of the Cardiovascular System: Anatomy, Physiology, Assessment, and Abnormalities

SCIENTISTS IN ACTION

9.1K 次观看.  Region Östergötland. 该协议描述了如何使用漫极化光谱学可以提高临床效用的毛细管填充试验。我们建议使用漫反射光谱视频和新的信息端点对健康志愿者毛细血管充盈的过程进行更详细的分析。

视频: Diffuse Reflectance Spectroscopy: Getting the Capillary Refill Test Under One's Thumb

Dual-mode Imaging of Cutaneous Tissue Oxygenation and Vascular Function

Accurate assessment of cutaneous tissue oxygenation and vascular function is important for appropriate detection, staging, and treatment of many health disorders such as chronic wounds. We report the development of a dual-mode imaging system for non-invasive and non-contact imaging of cutaneous tissue oxygenation and vascular function. The imaging system integrated an infrared camera, a CCD camera, a liquid crystal tunable filter and a high intensity fiber light source. A Labview interface was programmed for equipment control, synchronization, image acquisition, processing, and visualization. Multispectral images captured by the CCD camera were used to reconstruct the tissue oxygenation map. Dynamic thermographic images captured by the infrared camera were used to reconstruct the vascular function map. Cutaneous tissue oxygenation and vascular function images were co-registered through fiduciary markers. The performance characteristics of the dual-mode image system were tested in humans.

A dual-mode imaging system was developed for non-contact assessment of cutaneous tissue oxygenation and vascular function.

双模式成像，皮肤组织氧合和血管功能

Accurate assessment of cutaneous tissue oxygenation and vascular function is important for appropriate detection, staging, and treatment of many health ...

科研

医学

Non-invasive Optical Measurement of Cerebral Metabolism and Hemodynamics in Infants

Perinatal brain injury remains a significant cause of infant mortality and morbidity, but there is not yet an effective bedside tool that can accurately screen for brain injury, monitor injury evolution, or assess response to therapy. The energy used by neurons is derived largely from tissue oxidative metabolism, and neural hyperactivity and cell death are reflected by corresponding changes in cerebral oxygen metabolism (CMRO2). Thus, measures of CMRO2 are reflective of neuronal viability and provide critical diagnostic information, making CMRO2 an ideal target for bedside measurement of brain health.
Brain-imaging techniques such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT) yield measures of cerebral glucose and oxygen metabolism, but these techniques require the administration of radionucleotides, so they are used in only the most acute cases.
Continuous-wave near-infrared spectroscopy (CWNIRS) provides non-invasive and non-ionizing radiation measures of hemoglobin oxygen saturation (SO2) as a surrogate for cerebral oxygen consumption. However, SO2 is less than ideal as a surrogate for cerebral oxygen metabolism as it is influenced by both oxygen delivery and consumption. Furthermore, measurements of SO2 are not sensitive enough to detect brain injury hours after the insult 1,2, because oxygen consumption and delivery reach equilibrium after acute transients 3. We investigated the possibility of using more sophisticated NIRS optical methods to quantify cerebral oxygen metabolism at the bedside in healthy and brain-injured newborns. More specifically, we combined the frequency-domain NIRS (FDNIRS) measure of SO2 with the diffuse correlation spectroscopy (DCS) measure of blood flow index (CBFi) to yield an index of CMRO2 (CMRO2i) 4,5.
With the combined FDNIRS/DCS system we are able to quantify cerebral metabolism and hemodynamics. This represents an improvement over CWNIRS for detecting brain health, brain development, and response to therapy in neonates. Moreover, this method adheres to all neonatal intensive care unit (NICU) policies on infection control and institutional policies on laser safety. Future work will seek to integrate the two instruments to reduce acquisition time at the bedside and to implement real-time feedback on data quality to reduce the rate of data rejection.

We combined frequency-domain near-infrared spectroscopy measures of cerebral hemoglobin oxygenation with diffuse correlation spectroscopy measures of cerebral blood flow index to estimate an index of oxygen metabolism. We tested the utility of this measure as a bedside screening tool to evaluate the health and development of the newborn brain.

婴幼儿的脑代谢和血流动力学的非侵入式光学测量

Perinatal brain injury remains a significant cause of infant mortality  and morbidity, but there is not yet an effective bedside tool that can  accurately ...

Non-invasive Assessment of Microvascular and Endothelial Function

The authors have utilized capillaroscopy and forearm blood flow techniques to investigate the role of microvascular dysfunction in pathogenesis of cardiovascular disease. Capillaroscopy is a non-invasive, relatively inexpensive methodology for directly visualizing the microcirculation. Percent capillary recruitment is assessed by dividing the increase in capillary density induced by postocclusive reactive hyperemia (postocclusive reactive hyperemia capillary density minus baseline capillary density), by the maximal capillary density (observed during passive venous occlusion). Percent perfused capillaries represents the proportion of all capillaries present that are perfused (functionally active), and is calculated by dividing postocclusive reactive hyperemia capillary density by the maximal capillary density. Both percent capillary recruitment and percent perfused capillaries reflect the number of functional capillaries. The forearm blood flow (FBF) technique provides accepted non-invasive measures of endothelial function: The ratio FBFmax/FBFbase is computed as an estimate of vasodilation, by dividing the mean of the four FBFmax values by the mean of the four FBFbase values. Forearm vascular resistance at maximal vasodilation (FVRmax) is calculated as the mean arterial pressure (MAP) divided by FBFmax. Both the capillaroscopy and forearm techniques are readily acceptable to patients and can be learned quickly.
The microvascular and endothelial function measures obtained using the methodologies described in this paper may have future utility in clinical patient cardiovascular risk-reduction strategies. As we have published reports demonstrating that microvascular and endothelial dysfunction are found in initial stages of hypertension including prehypertension, microvascular and endothelial function measures may eventually aid in early identification, risk-stratification and prevention of end-stage vascular pathology, with its potentially fatal consequences.

Capillaroscopy is a non-invasive, relatively inexpensive methodology for directly visualizing the microcirculation. The forearm blood flow technique provides accepted non-invasive measures of endothelial function.

非侵入性的评估微血管和内皮功能

The authors have utilized capillaroscopy and forearm blood flow techniques to investigate the role of microvascular dysfunction in pathogenesis of ...

Multimodal Imaging and Spectroscopy Fiber-bundle Microendoscopy Platform for Non-invasive, In Vivo Tissue Analysis

Recent fiber-bundle microendoscopy techniques enable non-invasive analysis of in vivo tissue using either imaging techniques or a combination of spectroscopy techniques. Combining imaging and spectroscopy techniques into a single optical probe may provide a more complete analysis of tissue health. In this article, two dissimilar modalities are combined, high-resolution fluorescence microendoscopy imaging and diffuse reflectance spectroscopy, into a single optical probe. High-resolution fluorescence microendoscopy imaging is a technique used to visualize apical tissue micro-architecture and, although mostly a qualitative technique, has demonstrated effective real-time differentiation between neoplastic and non-neoplastic tissue. Diffuse reflectance spectroscopy is a technique which can extract tissue physiological parameters including local hemoglobin concentration, melanin concentration, and oxygen saturation. This article describes the specifications required to construct the fiber-optic probe, how to build the instrumentation, and then demonstrates the technique on in vivo human skin. This work revealed that tissue micro-architecture, specifically apical skin keratinocytes, can be co-registered with its associated physiological parameters. The instrumentation and fiber-bundle probe presented here can be optimized as either a handheld or endoscopically-compatible device for use in a variety of organ systems. Additional clinical research is needed to test the viability of this technique for different epithelial disease states.

Multimodal Imaging and Spectroscopy Fiber-bundle Microendoscopy Platform for Non-invasive, In Vivo Tissue Analysis

The assembly and use of a multimodal microendoscope is described which can co-register superficial tissue image data with tissue physiological parameters including hemoglobin concentration, melanin concentration, and oxygen saturation. This technique can be useful for evaluating tissue structure and perfusion, and can be optimized for individual needs of the investigator.

多峰成像和光谱学纤维束显微内窥镜纲要非侵入性，<em&gt;在体内</em&gt;组织分析

Recent fiber-bundle microendoscopy techniques enable non-invasive analysis of in vivo tissue using either imaging techniques or a combination of ...

生物工程

A Reproducible Computerized Method for Quantitation of Capillary Density using Nailfold Capillaroscopy

Capillaroscopy is a non-invasive, efficient, relatively inexpensive and easy to learn methodology for directly visualizing the microcirculation. The capillaroscopy technique can provide insight into a patient&#8217;s microvascular health, leading to a variety of potentially valuable dermatologic, ophthalmologic, rheumatologic and cardiovascular clinical applications. In addition, tumor growth may be dependent on angiogenesis, which can be quantitated by measuring microvessel density within the tumor. However, there is currently little to no standardization of techniques, and only one publication to date reports the reliability of a currently available, complex computer based algorithms for quantitating capillaroscopy data.1 This paper describes a new, simpler, reliable, standardized capillary counting algorithm for quantitating nailfold capillaroscopy data. A simple, reproducible computerized capillaroscopy algorithm such as this would facilitate more widespread use of the technique among researchers and clinicians. Many researchers currently analyze capillaroscopy images by hand, promoting user fatigue and subjectivity of the results. This paper describes a novel, easy-to-use automated image processing algorithm in addition to a reproducible, semi-automated counting algorithm. This algorithm enables analysis of images in minutes while reducing subjectivity; only a minimal amount of training time (in our experience, less than 1 hr) is needed to learn the technique.

Capillaroscopy is a non-invasive, efficient, relatively inexpensive and easy-to-learn methodology for directly visualizing capillaries in the microcirculation. However, only one publication to date describes the reliability of a complex software program available for quantitating capillaroscopy data. Here, we present a simple, reliable protocol for quantitating capillaries using a standardized algorithm.

对于毛细血管密度的定量使用甲襞Capillaroscopy可再生的计算机化方法

Capillaroscopy is a non-invasive, efficient, relatively inexpensive and easy to learn methodology for directly visualizing the microcirculation. The ...

Agarose-based Tissue Mimicking Optical Phantoms for Diffuse Reflectance Spectroscopy

This protocol describes how to make agarose-based tissue-mimicking phantoms and demonstrates how to determine their optical properties using a conventional optical system with an integrating sphere. Measuring systems for the acquisition of the diffuse reflectance and total transmittance spectra are constructed with a broadband white light source, a light guide, an achromatic lens, an integrating sphere, a sample holder, an optical fiber probe, and a multi-channel spectrometer. An acrylic mold consisting of two rectangular acrylic pieces and a U-shaped acrylic piece is constructed to create an epidermal phantom and a dermal phantom with whole blood. The application of a sodium dithionite (Na2S2O4) solution to the dermal phantom enables the researcher to deoxygenate hemoglobin in red blood cells distributed in the dermal phantom. The inverse Monte Carlo simulation with the diffuse reflectance and total transmittance spectra measured by a spectrometer with an integrating sphere is performed to determine the absorption coefficient spectrum &#181;a(&#955;) and the reduced scattering coefficient spectrum &#181;s&#39;(&#955;) of each layer phantom. A two-layered phantom mimicking the diffuse reflectance of human skin tissue is also demonstrated by piling up the epidermal phantom on the dermal phantom.

Here, we demonstrate how agarose-based tissue-mimicking optical phantoms are made and how their optical properties are determined using a conventional optical system with an integrating sphere.

基于琼脂糖组织模拟光学幽灵的漫反射光谱研究

This protocol describes how to make agarose-based tissue-mimicking phantoms and demonstrates how to determine their optical properties using a ...

Simultaneous Evaluation of Cerebral Hemodynamics and Light Scattering Properties of the In Vivo Rat Brain Using Multispectral Diffuse Reflectance Imaging

The simultaneous evaluation of cerebral hemodynamics and the light scattering properties of in vivo rat brain tissue is demonstrated using a conventional multispectral diffuse reflectance imaging system. This system is constructed from a broadband white light source, a motorized filter wheel with a set of narrowband interference filters, a light guide, a collecting lens, a video zoom lens, and a monochromatic charged-coupled device (CCD) camera. An ellipsoidal cranial window is made in the skull bone of a rat under isoflurane anesthesia to capture in vivo multispectral diffuse reflectance images of the cortical surface. Regulation of the fraction of inspired oxygen using a gas mixture device enables the induction of different respiratory states such as normoxia, hyperoxia, and anoxia. A Monte Carlo simulation-based multiple regression analysis for the measured multispectral diffuse reflectance images at nine wavelengths (500, 520, 540, 560, 570, 580, 600, 730, and 760 nm) is then performed to visualize the two-dimensional maps of hemodynamics and the light scattering properties of the in vivo rat brain.

Simultaneous Evaluation of Cerebral Hemodynamics and Light Scattering Properties of the In Vivo Rat Brain Using Multispectral Diffuse Reflectance Imaging

The simultaneous evaluation of cerebral hemodynamics and the light scattering properties of in vivo rat brain tissue is demonstrated using a conventional multispectral diffuse reflectance imaging system.

脑血流动力学和的光散射特性的同步评估<em&gt;体内</em&gt;大鼠脑使用多光谱漫反射成像

The simultaneous evaluation of cerebral hemodynamics and the light scattering properties of in vivo rat brain tissue is demonstrated using a conventional ...

神经科学

Retinal Vascular Reactivity as Assessed by Optical Coherence Tomography Angiography

The vascular supply to the retina has been shown to dynamically adapt through vasoconstriction and vasodilation to accommodate the metabolic demands of the retina. This process, referred to as retinal vascular reactivity (RVR), is mediated by neurovascular coupling, which is impaired very early in retinal vascular diseases such as diabetic retinopathy. Therefore, a clinically feasible method of assessing vascular function may be of significant interest in both research and clinical settings. Recently, in vivo imaging of the retinal vasculature at the capillary level has been made possible by the FDA approval of optical coherence tomography angiography (OCTA), a noninvasive, minimal risk and dyeless angiography method with capillary level resolution. Concurrently, physiological and pathological changes in RVR have been shown by several investigators. The method shown in this manuscript is designed to investigate RVR using OCTA with no need for alterations to the clinical imaging procedures or device. It demonstrates real time imaging of the retina and retinal vasculature during exposure to hypercapnic or hyperoxic conditions. The exam is easily performed with two personnel in under 30 min with minimal subject discomfort or risk. This method is adaptable to other ophthalmic imaging devices and the applications may vary based on the composition of the gas mixture and patient population. A strength of this method is that it allows for an investigation of retinal vascular function at the capillary level in human subjects in vivo. Limitations of this method are largely those of OCTA and other retinal imaging methods including imaging artifacts and a restricted dynamic range. The results obtained from the method are OCT and OCTA images of the retina. These images are amenable to any analysis that is possible on commercially available OCT or OCTA devices. The general method, however, can be adapted to any form of ophthalmic imaging.

This article describes a method for measuring retinal vasculature reactivity in vivo with human subjects using a gas breathing provocation technique to deliver vasoactive stimuli while acquiring retinal images.

光相一致性断层扫描血管造影评估的视网膜血管反应

The vascular supply to the retina has been shown to dynamically adapt through vasoconstriction and vasodilation to accommodate the metabolic demands of ...

Real-Time Monitoring of Neurocritical Patients with Diffuse Optical Spectroscopies

Neurophysiological monitoring is an important goal in the treatment of neurocritical patients, as it may prevent secondary damage and directly impact morbidity and mortality rates. However, there is currently a lack of suitable non-invasive, real-time technologies for continuous monitoring of cerebral physiology at the bedside. Diffuse optical techniques have been proposed as a potential tool for bedside measurements of cerebral blood flow and cerebral oxygenation in case of neurocritical patients. Diffuse optical spectroscopies have been previously explored to monitor patients in several clinical scenarios ranging from neonatal monitoring to cerebrovascular interventions in adults. However, the feasibility of the technique to aid clinicians by providing real-time information at the bedside remains largely unaddressed. Here, we report the translation of a diffuse optical system for continuous real-time monitoring of cerebral blood flow, cerebral oxygenation, and cerebral oxygen metabolism during intensive care. The real-time feature of the instrument could enable treatment strategies based on patient-specific cerebral physiology rather than relying on surrogate metrics, such as arterial blood pressure. By providing real-time information on the cerebral circulation at different time scales with relatively cheap and portable instrumentation, this approach may be especially useful in low-budget hospitals, in remote areas and for&#160;monitoring in open fields (e.g., defense and sports).

Presented here is a protocol for non-invasively monitoring cerebral hemodynamics of neurocritical patients in real-time and at the bedside using diffuse optics. Specifically, the proposed protocol uses a hybrid diffuse optical systems to detect and display real-time information on cerebral oxygenation, cerebral blood flow and cerebral metabolism.

使用漫反射光谱实时监测神经危重症患者

Neurophysiological monitoring is an important goal in the treatment of neurocritical patients, as it may prevent secondary damage and directly impact ...

Non-Invasive Monitoring of Microvascular Oxygenation and Reactive Hyperemia using Hybrid, Near-Infrared Diffuse Optical Spectroscopy for Critical Care

The detection of levels of impairment in microvascular oxygen consumption and reactive hyperemia is vital in critical care. However, there are no practical means for a robust and quantitative evaluation. This paper describes a protocol to evaluate these impairments using a hybrid near-infrared diffuse optical device. The device contains modules for near-infrared time-resolved and diffuse correlation spectroscopies and pulse-oximetry. These modules allow the non-invasive, continuous, and real-time measurement of the absolute, microvascular blood/tissue oxygen saturation (StO2) and the blood flow index (BFI) along with the peripheral arterial oxygen saturation (SpO2). This device uses an integrated, computer-controlled tourniquet system to execute a standardized protocol with optical data acquisition from the brachioradialis muscle. The standardized vascular occlusion test (VOT) takes care of the variations in the occlusion duration and pressure reported in the literature, while the automation minimizes inter-operator differences. The protocol we describe focuses on a 3-min occlusion period but the details described in this paper can readily be adapted to other durations and cuff pressures, as well as other muscles. The inclusion of an extended baseline and post-occlusion recovery period measurement allows the quantification of the baseline values for all the parameters and the blood/tissue deoxygenation rate that corresponds to the metabolic rate of oxygen consumption. Once the cuff is released, we characterize the tissue reoxygenation rate, magnitude, and duration of the hyperemic response in BFI and StO2. These latter parameters correspond to the quantification of the reactive hyperemia, which provides information about the endothelial function. Furthermore, the above-mentioned measurements of the absolute concentration of oxygenated and deoxygenated hemoglobin, BFI, the derived metabolic rate of oxygen consumption, StO2, and SpO2 provide a yet-to-be-explored rich data set that can exhibit disease severity, personalized therapeutics, and management interventions.

We describe a protocol to non-invasively and continuously measure absolute microvascular blood flow index and blood oxygen saturation using a multi-modal device based on near-infrared diffuse optics. We then evaluate the metabolic rate of oxygen consumption and reactive hyperemia utilizing a vascular occlusion test.

漫反射光谱分析: 在拇指下进行毛细管填充试验

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