这项工作得到了德克萨斯大学阿灵顿跨学科研究项目补助金的支持。

本议定书遵循德克萨斯大学阿林顿机构审查委员会的指导方针, 符合《赫尔辛基宣言》最新版本规定的标准。因此, 在开始研究程序之前 (而且应该) 获得书面知情同意。
1. 仪器仪表
注: 以下仪器描述是基于我们实验室使用的近红外线 (近红外) 光谱仪和数据采集系统 (请参阅材料表)。因此, 指令包括这些设备的最佳功能所必需的步骤。这些步骤包括使用随附的软件和校准幻影对近红外探测器进行校准, 以及应用暗布排除周围光线。如果使用了不同的数据收集硬件和/或软件, 调查人员应参考他们自己的特定用户手册进行校准和环境光的考虑。图 1演示了下面所描述的实验设置和检测。
<ol><li>指示主体仰卧与他们的腿在一个较低的身体负压 (LBNP) 室 (图 1A), 使他们的皮带线近似地甚至与打开 LBNP 框。有关如何生成 LBNP 室的说明, 请参见引用17.
</li>
	<li>放置三心电图电极的主题: 两个在一个较低的, 锁骨上的位置和一个在主题的左侧内侧到髂嵴。这种配置提供了最好的结果, 由于有限的访问下肢, 上肢的仪器, 和手臂运动在手握演习。</li>
	<li>将无创血压监测模块放在主体手腕上。将手指血压袖口放在每个手指上, 并将它们连接到模块 (图 1B)。确保手指的血压袖口是正确的校准根据用户的手册陪同您的设备。</li>
	<li>指示该主题掌握一个手握测功机 (恒光达) 与他们的非显性手臂在一个轻微的绑架的位置。手臂应舒适地放置在床边的桌子上。恒光达的距离和角度应进行调整, 以使最佳握杆强度最小的臂移动(图 1C)。</li>
	<li>把恒光达固定在床边的桌子上。</li>
	<li>测量参与者的最大自愿收缩 (MVC)。告诉参与者, 当提示时, 他们必须尽可能用力挤压恒光达, 而只需要使用手和前臂的肌肉。指导的主题, 他们必须避免招募他们的上臂, 胸部, 肩膀, 或腹部肌肉时, 执行最大的抓地力。</li>
	<li>重复步骤1.6 三次, 至少相隔六十年代. 记录所达到的最大力 (最好为 3)。这一最大力将用于计算骨骼肌氧化能力和神经血管耦合的运动强度 (下)。</li>
	<li>在练习手的上臂周围放置一个快速充气袖口。将航空公司从快速的通货膨胀控制器连接到袖口。</li>
	<li>鉴别屈趾深肌腱。使用皮肤标记来标定可触摸肌肉的边界。</li>
	<li>确保根据您的设备附带的用户手册正确校准近红外光谱仪。清洁近红外探针将定位与酒精准备擦拭的皮肤。</li>
	<li>将近红外探针放在肌肉腹部的中心 (屈趾深肌腱) 上, 并将其安全地贴在前臂上。</li>
	<li>用深色布包裹探头和前臂, 尽量减少环境光线的干扰 (图 1C,图 1D)。</li>
	<li>当准备完成研究的功能 sympatholysis 部分时, 将主语密封到 LBNP 室。</li>
</ol>2. 骨骼肌氧化能力
注: 图2描述了用于测量骨骼肌氧化能力的实验程序的代表性数据跟踪。此实验方法以前已对体内磷夫人18和原位肌肉 respirometry19进行了验证, 并获得了广泛的接受20。
<ol><li>如上文所示 (检测) 来测量主题。</li>
	<li>通过近红外探针, 指示主体在监视脱氧 (HHb) 和 oxyhemoglobin (HbO2) 的同时, 仍要躺2分钟。 注意: 此休息期允许主题从与检测过程相关的任何移动工件中恢复, 并确保基线测量稳定。如果在2分钟后没有发生明显的波动, 则可以在稳定状态或静止基线上考虑该问题。</li>
	<li>在袖口闭塞之前, 通知你的主题, 你将充气袖口。充气上臂袖口至少 30 mmHg 以上收缩压5分钟 (即, suprasystolic)。指导该主题保持他们的手臂仍然和放松尽可能在袖口通货膨胀和后袖通货紧缩。 注: 这5分钟肱动脉袖套闭塞协议密切反映目前接受的临床标准为血管闭塞测试21,22,23,24,25。</li>
	<li>记录袖套闭塞期间的初始/基线值 (在袖扣前) 和组织饱和度的最低值 (2), 并确定这两个值之间的中点。 <img alt="Equation 1" src="/files/ftp_upload/57317/57317eq1.jpg">
</li>
	<li>允许主体从袖扣中恢复, 并返回静止基线值。一旦主题保持了至少1分钟的休息基线, 继续下一步。</li>
	<li>指导受压, 并保持一个等距的手握在50% 的 MVC。鼓励主体保持其等距收缩, 直到组织 desaturates 50%。在达到这个价值后, 告诉他们放松自己的手, 并告知他们不再需要运动或运动。</li>
	<li>在运动停止后 3-5 秒内, 管理以下快速袖扣系列 (一系列 = 1 通货膨胀 + 1 通货紧缩), 如以前建立的18: 系列 #1-6: 5 s on/5 s 关闭 系列 #7-10: 7 s on/10 s 关闭 系列 #11-14: 十年代 on/15 s 关闭 系列 #15-18: 十年代 on/20 s 关闭</li>
	<li>完成 18th通货膨胀/通货紧缩系列后, 指示该主体休息, 允许组织饱和度返回初始基线值。在这些值保持至少2分钟的一致性之后, 重复步骤2.4 和2.5。</li>
	<li>
骨骼肌氧化能力的计算
	<ol>
<li>计算2中每个单独的18个袖闭塞的变化斜率, 形成图 2C中所示的 monoexponential 恢复点。</li>
		<li>将计算数据从2.7 调整为以下 monoexponential 曲线18,19,26 y = 端Δ x e-kt 注: ' y ' 是在袖扣期间的相对肌肉耗氧率 (mV̇O2), "末端" 代表 mV̇O2在运动停止后立即;delta ("Δ") 表示 mV̇O2中的更改从 rest 到练习结束;"k" 是拟合速率常数;' t ' 是时间。头计算为 1/k。</li>
	</ol>
</li>
</ol>3. 反应性充血
注: 在图 3中描述了用于测量反应性充血的实验过程的代表性数据跟踪。
<ol><li>以主题说谎仰卧和被测量如上面描述 (仪器仪表), 指示主题说谎尽可能仍然。</li>
	<li>一旦该主题达到了一致的休息状态, 继续记录至少1分钟基线数据, 然后迅速充气一个血压袖口上手臂的 suprasystolic 压力 (30 mmHg 以上的收缩期血压)。</li>
	<li>在5分钟的标记, 迅速压缩袖口, 而记录充血的反应。</li>
	<li>继续录制至少3分钟以捕获主题的恢复。</li>
	<li>
反应性充血的计算 注: 计算的近红外光谱参数如图3所示。<ol>
<li>在动脉袖套闭塞发生之前, 将基线停用2作为平均值为2 1 全分钟。</li>
		<li>确定休息的骨骼肌代谢率为饱和率 (即,平均斜率) 在袖套闭塞 (定义为斜坡 1)27,28。</li>
		<li>计算反应性充血如下: a) 袖扣释放后的平均上坡 (即,再灌注率, 定义为斜率 2), 计算从袖口释放的时刻, 通过线性增加阶段的反弹痕迹; b) 在袖口释放后达到的最高的2值 (表示为停用2max); c) 曲线下的反应性充血区 (联合自卫队);计算从袖扣时间到 1, 2 和3分钟后袖套闭塞 (联合自卫队1分钟, 哥伦比亚自卫队2分钟, 和哥伦比亚自卫队3分钟);和 d) 充血准备金, 计算为高于基线的2的更改, 并报告为百分比 (%) 更改。此值计算为在阻塞后回弹期间达到的最高饱和度减去步骤3.5.1 中计算的平均饱和度 (见上文)。 注: 基线数据的大差异将极大地影响充血保护区的解释。</li>
	</ol>
</li>
</ol>4. 功能 Sympatholysis
注意: 描述用于测量功能 sympatholysis 的实验过程的典型数据跟踪显示在图 4中。
<ol><li>如上文所示 (检测) 来测量主题。</li>
	<li>确保密封在 LBNP 室。</li>
	<li>随着主题静止和静止, 收集3分钟的基线数据。</li>
	<li>在3分钟的标记, 打开真空。调整真空度, 使 LBNP 腔内的压力介于-20 至-30 mmHg 之间。允许真空运行2分钟, 同时监测主体的反应。</li>
	<li>在5分钟的标记, 关闭真空, 让主题休息3分钟。</li>
	<li>在8分钟的标记, 启动语音提示引导主题通过节奏的手抓练习 (20% MVC)。</li>
	<li>确认主题是保持他们的挤压整个每个抓取阶段, 并在每次重复之间完全放松。监测他们的力量输出, 并确认他们是实现 20% MVC 每一个抓地力。继续练习直到11分钟标记。</li>
	<li>在11分钟的标记, 打开真空鼓励主题继续他们的韵律运动。允许真空从 11-13 分钟运行, 然后关闭它。</li>
	<li>让主题继续执行有节奏的手握练习在20% 他们的 MVC 为另外的2分钟。运动停止后, 让主题静静地休息, 躺着不动。</li>
	<li>
计算功能 Sympatholysis
	<ol>
<li>将 oxyhemoglobin 与 LBNP 的变化正常化为总的不稳定信号 (TLS), 在5分钟袖套闭塞期间确定: <img alt="Equation 2" src="/files/ftp_upload/57317/57317eq2.jpg"> <img alt="Equation 3" src="/files/ftp_upload/57317/57317eq3.jpg">
</li>
		<li>将每个事件计算为每个事件的最终20分钟平均值。</li>
		<li>计算 oxyhemoglobin 减少的运动诱发衰减: <img alt="Equation 4" src="/files/ftp_upload/57317/57317eq4.jpg">
</li>
	</ol>
</li>
</ol>

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作者声明他们没有竞争的财政利益。

本文所述方法可在单个诊所或实验室访问中进行无创、无反应性充血、神经血管耦合和骨骼肌氧化能力的临床评价。
关键考虑事项
虽然近红外光谱是相对健壮和易于使用, 收集这些数据需要仔细放置的 optodes 直接在肌肉腹部, 固定到位, 以避免运动工件, 并覆盖在昏暗的房间里的黑色乙烯基板, 以避免外部光对近红外的干扰。此外, 获得高质量的数据很大程度上依赖于测试人员与主题之间的清晰沟通, 以及测试团队。我们和其他人发现, 在进行适当的照顾和注意时, 近红外光谱在一次考察访问中具有高度的可重复性, 并且横跨多个访问10,11,24,29。此外, 本文报告的生理结果变量 (即,骨骼肌氧化能力, 反应性充血和神经血管耦合) 对实验和临床干预都很敏感, 无论是在研究访问30,31,10,11。
目前对近红外光谱结果变量的适当报告达成了有限的共识。例如, 当测量骨骼肌氧化能力时, 调查人员已经适应 HbO 的恢复动力学232, HHb19, Hb差异30和组织 O2饱和度 (当前研究和其他33).同样, 在结果变量中也有类似的传播, 也被报道为基于近红外光谱的反应性充血。34,35,36,37其中的一些差异可能与所使用的近红外仪器的类型有关。例如, 频域设备 (如此处所用) 提供了 HbO2和 HHb 的绝对量化, 因此可能不会受到总的 Hb 内容 (不需要更正数据) 的急性变化的影响。相比之下, 连续波器件受总血红蛋白的急性变化影响很大, 需要数据校正25。
修改和疑难解答
近红外光谱的一个重要和目前不可避免的局限性是它的穿透深度有限 (约2厘米)。因此, 肢体肥胖可以显著减少-甚至完全消除-近红外光谱信号, 并应考虑在筛选潜在的对象。为了控制这一情况, 研究者们被鼓励测量前臂皮脂厚度, 并排除有显著外周肥胖的参与者。
任何能够调节血管反应性、神经血管耦合和/或骨骼肌氧化能力的因素 (例如,药物、基因突变、等等) 确实会影响此处描述的主要终点测量。.因此, 应鼓励调查人员在调整本议定书和规划今后的试验时考虑到这些因素。
对于功能性 sympatholysis 的确定, 调查人员可能希望包括第二个休息 LBNP 挑战, 以确保信号仍然存在, 并认为在演习 LBNP 的差异不是简单地由于信号或测量误差的损失。建议允许 3-5 分钟允许 oxyhemoglobin 信号完全恢复到基线值, 然后再重复静止的 LBNP 挑战。
掌握这项技术以后的应用或方向
近红外光谱利用激光来评估组织中氧合和脱氧血红蛋白的浓度。在反应性充血和功能性 sympatholysis 的测量中, 这些参数的相对变化被认为代表微血管流动的变化。弥散相关谱 (DCS) 是一种新兴的近红外成像方法, 除了评价氧-和脱氧浓度外, 还可以量化微血管灌注38。鉴于这两种成像方法之间的明显相似之处, 将 DCS 纳入拟议的技术几乎是无缝的, 并可进一步洞察微血管功能和灌注的量化。
一旦这种技术被掌握, 应用到临床人群, 如心力衰竭患者, 将提供重要的机械洞察力的运动不耐受和心血管功能障碍。

充血对短暂的组织缺血的反应已成为一种关键的非侵入性测量 (微) 血管功能。在导管动脉闭塞期间, 下游动脉扩张, 以抵消缺血性的侮辱。在阻断后, 血管阻力的减少导致充血, 其大小取决于一个人的能力来扩张下游微管。虽然反应性充血是心血管事件的一个强有力的独立预测因子1,2 , 因此一个临床重要的终点, 它的功能意义, 锻炼耐受性和生活质量是不太清楚。
事实上, 动态运动是一种主要的心血管压力, 需要高度协调的神经血管反应, 以便将氧气输送与新陈代谢需求相匹配。例如, 骨骼肌血流可以增加近100倍, 在单独的肌肉收缩3, 这将压倒心脏的抽水能力, 如果这样的血流动力学反应被推断为全身运动。因此, 为了避免严重的低血压, 交感神经 (即,收缩) 神经活动增加, 重新分配心脏输出远离非活动和内脏组织和对主动骨骼肌4。交感神经流出也被定向到运动骨骼肌5;然而, 局部代谢信号减弱收缩反应, 以确保足够的组织氧气输送6,7,8,9,10, 11. 总的来说, 这个过程被称为功能 sympatholysis12, 对运动过程中骨骼肌血流的正常调节是必不可少的。由于骨骼肌血流是有氧能力的关键决定因素--生命质量和心血管疾病发病率和死亡率的独立预测因子13-了解骨骼肌血流和组织氧的控制运动期间分娩具有重要的临床意义。
然而, 氧气的传递只是菲克方程的一半, 氧气的利用满足了等式的另一半。在氧利用的主要决定中, 线粒体氧化磷酸化对于在静止和运动期间为细胞过程提供足够的能量起着至关重要的作用。事实上, 肌肉氧化能力的损害可以限制功能能力和生活质量14,15,16。各种措施通常用于提供肌肉氧化能力指标, 包括侵入性肌肉活检和昂贵和耗时的磁共振光谱学 (夫人) 技术。
在这里, 我们提出了一种新的, 非侵入性的方法, 使用近红外光谱分析, 以评估这三个主要临床终点 (活性充血, sympatholysis 和肌肉氧化能力) 在一个单一的诊所或实验室访问。该方法的主要优点是三倍: 首先, 该技术易于携带, 成本相对较低, 易于执行。目前的多普勒超声检测反应性充血的方法是高度依赖于操作者-需要广泛的技能和培训-并需要复杂, 高成本, 数据采集硬件和后处理软件。此外, 这可能被引入到临床和/或大型临床试验, 为床边监测或测试的疗效。其次, 根据该方法, 该技术特别注重骨骼肌微血管, 提高了技术的整体特异性。其他方法使用多普勒超声聚焦在上游导管容器和推断变化下游, 这可能会减弱信号。第三, 这种技术是完全无侵入性的。骨骼肌氧化能力传统上是用侵袭性和痛苦的肌肉活检来评估的, 功能 sympatholysis 可以用动脉内注射 sympathomimetics 和 sympatholytics 来评估。这种方法完全避免了这些要求。

<table><tbody><tr><td>Dual-channel OxiplexTS Near-infrared spectroscopy machine</td><td>Iss Medical</td><td>101</td><td></td></tr><tr><td>NIRS muscle sensor</td><td>Iss Medical</td><td>201.2</td><td></td></tr><tr><td>E20 Rapid cuff inflation system</td><td>Hokanson</td><td>E20</td><td></td></tr><tr><td>AG101 Air Source</td><td>Hokanson</td><td>AG101</td><td></td></tr><tr><td>Smedley Handgrip dynometer (recording)</td><td>Stolting</td><td>56380</td><td></td></tr><tr><td>Powerlab 16/35, 16 Channel Recorder</td><td>ADInstruments</td><td>PL3516</td><td></td></tr><tr><td>Human NIBP Set</td><td>ADInstruments</td><td>ML282-SM</td><td></td></tr><tr><td>Bio Amp</td><td>ADInstruments</td><td>FE132</td><td></td></tr><tr><td>Quad Bridge Amp</td><td>ADInstruments</td><td>FE224</td><td></td></tr><tr><td>Connex Spot Monitor</td><td>Welch Allyn</td><td>71WX-B</td><td></td></tr><tr><td>Origin(Pro) graphing software</td><td>OrignPro</td><td>Pro</td><td></td></tr><tr><td>Lower body negative pressure chamber</td><td>Physiology Research Instruments</td><td>standard unit</td><td></td></tr></tbody></table>

skeletal muscle neurovascular coupling, oxidative capacity, and microvascular function with 'one stop shop' near-infrared spectroscopy

运动是一种主要的血流动力学压力, 需要高度协调的神经血管反应, 以便将氧气输送与新陈代谢需求相匹配。反应性充血 (在短时间内组织缺血) 是心血管事件的独立预测因子, 为血管的健康和舒张能力提供了重要的洞察力。骨骼肌氧化能力在健康和疾病中同样重要, 因为它决定了 myocellular 过程的能量供应。在这里, 我们描述了一个简单的, 非侵入性的方法, 使用近红外光谱评估这些主要临床终点 (反应性充血, 神经血管耦合, 肌肉氧化能力) 在一个单一的诊所或实验室访问。不同于多普勒超声, 磁共振图像/光谱学, 或侵入导管的流量测量或肌肉活检, 我们的方法是较少的操作者依赖, 低成本, 完全没有侵入。我们实验室的代表性数据连同先前发表的文献中的摘要数据, 说明了每个端点的效用。一旦掌握了这种技术, 应用到临床人群将提供重要的机械洞察力的运动不耐受和心血管功能障碍。

骨骼肌氧化能力
图 2说明了在近红外光谱衍生骨骼肌氧化能力评估期间有代表性的参与者反应。面板 a 显示了5分钟的动脉袖套闭塞协议, 手柄运动, 和间歇性动脉闭塞在运动恢复期间的组织饱和度剖面。小组 B 说明在恢复期间歇性动脉闭塞期间, 预期的组织饱和/再饱和度剖面。饱和的速率与肌肉耗氧率成正比, 并且在每一个间歇性袖套闭塞期的 C 组中绘制。计算后的肌肉耗氧量恢复数据符合 monoexponential 曲线, 获得了恢复时间常数。使用同样的方法, 越来越多的研究已经评估了骨骼肌肉氧化能力的健康和疾病, 跨各种肌肉组 (表 1)。
反应性充血
图 3说明了有代表性的血管闭塞试验中近红外光谱衍生的反应性充血剖面。同样的方法已经在广泛的研究人群和肌肉群中使用, 并取得了良好的成功 (表 2)。数据表明, 近红外光谱衍生反应性充血不仅为血管反应性提供了有价值的洞察力, 而且具有很强的适应性和临床意义。
功能 Sympatholysis
Table3总结现有的文献, 使用与本文描述的完全相同的神经血管耦合方法来测量功能性 sympatholysis, 同时显示机械和临床相关结果。在健康的控制对象中, 当 LBNP 叠加在轻度手柄时, 肌肉氧合的反射减少了 50% (图 4)。在运动过程中, 如心血管或神经系统疾病 (表 3) 不能减弱交感神经 (收缩) 神经活动, 就会扰乱氧气输送和利用之间的平衡, 并导致功能性肌肉缺.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/57317/57317fig1.jpg"> 图1。实验设置和检测.(A)有代表性的实验性的设置, 一个典型的主题仰卧在床上, 他们的腿在 LBNP 室和充分的检测。(B)占主导地位的手臂, 采用非侵入式跳动式血压装置进行跳动式动脉血压测量, 以及用于校准和验证跳动系统的肱动脉血压袖套。非主导臂的(C)检测。该手舒适地抓取手柄测功机 (连接到数据采集系统), 前臂肌肉用近红外光谱探针进行检测。(D)一旦进行了检测, 近红外 optodes 被黑色乙烯基布覆盖 (以消除环境光线的干扰)。此外, 快速袖扣充气系统被放置在肱动脉。<a href="https://cloudflare-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/57317/57317fig1large.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/57317/57317fig2.jpg"> 图2。骨骼肌氧化能力协议。(a)通过近红外光谱测量的代表性主题的原始数据跟踪, 显示组织饱和度 (2) 随时间推移。在建立稳定基线后, 非显性臂的肱动脉阻塞五分钟, 以建立主体的饱和储备 (基线保持2与最低点之间的差异)。在从闭塞恢复后, 该主题被指示执行50% 等距手柄, 其次是18快速袖扣膨胀系列, 以评估肌肉氧消耗恢复动力学。(B)数据分析则通过计算每个袖套咬合序列的平均坡度, 然后进行离线操作;这里用假想的袖套遮挡系列数据来说明。(C)为了计算肌肉氧合的恢复时间常数, 18 快速袖闭塞 (即,后锻炼后肌肉氧消耗, mV̇O2) 的每一个斜坡都是按时间绘制的, 适合于monoexponential 曲线。<a href="https://cloudflare-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/57317/57317fig2large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/57317/57317fig3.jpg"> 图3。反应性充血实验规程。以仰卧位为准, 记录至少1分钟基线数据, 其次为5分钟总动脉袖闭塞, 并在袖扣后至少3分钟恢复。注意骨骼肌氧化容量协议 (图 2) 和此协议之间明显的重叠。"基线" 定义动脉袖套闭塞之前的时间段。"斜率 1" 定义了袖套闭塞期间的饱和率, 被认为是一种静止骨骼肌代谢率的测量方法。在缺血期间获得的最低的2值被定义为 "vasodilate2最小", 并被认为是对缺血性刺激的一种测量方法。组织饱和再灌注率为 "斜率 2", 是反应性充血的指标;如2的最大值, 以及曲线下的反应性充血区 (联合自卫队)。为了深入了解充血保留,2最大值表示为从基线更改的百分比。<a href="https://cloudflare-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/57317/57317fig3large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/57317/57317fig4.jpg"> 图4。功能 sympatholysis 实验协议。左面板: 来自代表主题的原始数据跟踪。在 LBNP 室仰卧的情况下, 允许3分钟稳定状态基线数据收集。打开 LBNP 到-20 mmHg 2 分钟 Oxyhemoglobin/肌红蛋白应减少反应的反射交感神经收缩 (蓝圈, 阴影区)。允许2分钟的恢复。要求在 20% MVC (在数据收集之前测量) 的主题进行有节奏的手柄练习。经过3分钟的韵律锻炼, 重复-20 mmHg LBNP 2 分钟, 而该科目继续行使, 其次是2分钟的运动, 没有 LBNP。oxyhemoglobin/肌红蛋白的减少应显著减弱 (红圈, 阴影区)。如果还没有执行, 在锻炼臂的肱动脉上充气一个血压袖扣5分钟, 以确定该学科的饱和范围。请注意, 图中的阴影区域只用来突出 oxyhemoglobin/肌红蛋白的变化;有关如何分析用于计算 sympatholysis 的结果变量的详细信息, 请参阅协议。右面板: LBNP 引起 oxyhemoglobin/肌红蛋白在休息和手柄运动中的变化, 从左边的数据计算。<a href="https://cloudflare-jove-com.bdigitaluss.remotexs.co/files/ftp_upload/57317/57317fig4large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always"><tbody>
<tr>
<td>参考/数据集</td>
			<td>研究人口</td>
			<td>样本大小 n)</td>
			<td>参加者年龄 (年)</td>
			<td>头 (τ) s)</td>
			<td>肌肉组</td>
			<td>报告的近红外变量</td>
			<td>设备</td>
		</tr>
<tr>
<td>布里曾丹et al。(2013)</td>
			<td>耐力运动员</td>
			<td>8</td>
			<td>25 @ 3</td>
			<td>19</td>
			<td>股外侧肌</td>
			<td>Hb差异/总血容量</td>
			<td>连续波 (Oxymon MK III)</td>
		</tr>
<tr>
<td>瑞安et al。(2014)</td>
			<td>年轻, 健康</td>
			<td>21</td>
			<td>26 @ 2</td>
			<td>55</td>
			<td>股外侧肌</td>
			<td>HHb</td>
			<td>连续波 (Oxymon MK III)</td>
		</tr>
<tr>
<td rowspan="2">南部et al。(2015)</td>
			<td>老人</td>
			<td>23</td>
			<td>61 @ 5</td>
			<td>63</td>
			<td>手腕屈肌</td>
			<td rowspan="2">Hb差异
</td>
			<td>连续波 (Oxymon MK III)</td>
		</tr>
<tr>
<td>老年人 + 心力衰竭</td>
			<td>16</td>
			<td>65 @ 7</td>
			<td>77</td>
			<td>手腕屈肌</td>
			<td>连续波 (Oxymon MK III)</td>
		</tr>
<tr>
<td rowspan="2">阿达米et al。(2017)</td>
			<td>吸烟者与正常通气</td>
			<td>23</td>
			<td>63 @ 7</td>
			<td>80</td>
			<td>前臂内侧</td>
			<td rowspan="2">组织饱和度指数 (TSI)</td>
			<td>连续波 (Portamon)</td>
		</tr>
<tr>
<td>COPD 金2-4</td>
			<td>16</td>
			<td>64 @ 9</td>
			<td>100</td>
			<td>前臂内侧</td>
			<td>连续波 (Portamon)</td>
		</tr>
<tr>
<td>埃里克森et al。(2013)</td>
			<td>脊髓损伤</td>
			<td>9</td>
			<td>43 @ 11</td>
			<td>143</td>
			<td>股外侧肌</td>
			<td>HbO2 </td>
			<td>连续波 (Oxymon MK III)</td>
		</tr>
</tbody></table>表 1: 通过近红外光谱测量骨骼肌肉氧化能力的过去发表的报告摘要。
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always"><tbody>
<tr>
<td>参考</td>
			<td>研究人口</td>
			<td>肌肉组</td>
			<td>报告的结果</td>
			<td>结果值</td>
		</tr>
<tr>
<td rowspan="4">拉克鲁瓦, J 生物医学选择, 2012</td>
			<td rowspan="4">健康男性</td>
			<td rowspan="4">前臂</td>
			<td>峰值 Oxyhemoglobin</td>
			<td>28.05 @ 3.15 微米</td>
		</tr>
<tr>
<td>峰值总血红蛋白</td>
			<td>10.56 @ 1.80 微米</td>
		</tr>
<tr>
<td>将速率提高到 HbO 的峰值2
</td>
			<td>0.75 ~ 0.22 微米/秒</td>
		</tr>
<tr>
<td>提高速率到峰值总血红蛋白</td>
			<td>0.52 ~ 0.16 微米/秒</td>
		</tr>
<tr>
<td rowspan="3">Kragelj, Ann 生物医学英语, 2001</td>
			<td rowspan="3">周围血管疾病</td>
			<td rowspan="3">前臂</td>
			<td>耗氧量</td>
			<td>0.68 @ 0.04 毫升/分钟</td>
		</tr>
<tr>
<td>高峰时间</td>
			<td>153十六年代</td>
		</tr>
<tr>
<td>HbO 的最大绝对变化2
</td>
			<td>2.93 @ 0.22 微米/100 毫升</td>
		</tr>
<tr>
<td rowspan="2">Suffoletto,复苏, 2012</td>
			<td rowspan="2">心脏停搏后 ICU Admittants</td>
			<td rowspan="2">鱼际隆起</td>
			<td>饱和率</td>
			<td>-5.6 @ 2%/分钟</td>
		</tr>
<tr>
<td>Resaturation 率</td>
			<td>0.9 @ 0.6%/秒</td>
		</tr>
<tr>
<td rowspan="3">季莫普洛斯,呼吸道护理, 2013</td>
			<td rowspan="3">肺动脉高压</td>
			<td rowspan="3">鱼际隆起</td>
			<td>基线饱和度与 21% O2
</td>
			<td>65.8 @ 14.9%</td>
		</tr>
<tr>
<td>O2 21% O2的消耗率
</td>
			<td>35.3 @ 9.1%/分钟</td>
		</tr>
<tr>
<td>21% O2的再灌注率
</td>
			<td>535 @ 179%/分钟</td>
		</tr>
<tr>
<td rowspan="2">Doerschug, Am J Physiol 心脏中国保监会 Physiol, 2007</td>
			<td rowspan="2">器官衰竭 & 脓毒症</td>
			<td rowspan="2">前臂</td>
			<td>基线饱和度</td>
			<td>84%</td>
		</tr>
<tr>
<td>复氧率</td>
			<td>3.6%/秒</td>
		</tr>
<tr>
<td rowspan="3">Mayeur,暴击治疗医学, 2011</td>
			<td rowspan="3">脓毒性休克</td>
			<td rowspan="3">鱼际隆起</td>
			<td>基线饱和度</td>
			<td>80 @ 1.0%</td>
		</tr>
<tr>
<td>饱和斜坡</td>
			<td>-9.8 @ 3.7%/分钟</td>
		</tr>
<tr>
<td>恢复斜坡</td>
			<td>2.3 @ 1.4%/秒</td>
		</tr>
<tr>
<td rowspan="5">McLay, Exp Physiol, 2016</td>
			<td rowspan="5">健康男性</td>
			<td rowspan="5">胫骨前</td>
			<td>基线饱和度</td>
			<td>71.3 @ 2.9%</td>
		</tr>
<tr>
<td>最小饱和度</td>
			<td>44.8 @ 8.6%</td>
		</tr>
<tr>
<td>饱和斜坡</td>
			<td>-0.1 @ 0.03%/秒</td>
		</tr>
<tr>
<td>恢复斜坡</td>
			<td>1.63 @ 0.5%/秒</td>
		</tr>
<tr>
<td>峰值饱和度</td>
			<td>82.6 @ 2.3%</td>
		</tr>
<tr>
<td rowspan="4">McLay, Physiol 代表, 2016</td>
			<td rowspan="4">健康男性</td>
			<td rowspan="4">胫骨前</td>
			<td>基线饱和度</td>
			<td>71.1 @ 2.4%</td>
		</tr>
<tr>
<td>最小饱和度</td>
			<td>46.2 @ 7.5%</td>
		</tr>
<tr>
<td>峰值饱和度</td>
			<td>82.1 @ 1.4%</td>
		</tr>
<tr>
<td>恢复斜坡</td>
			<td>1.32 @ 0.38%/秒</td>
		</tr>
</tbody></table>表 2: 使用近红外光谱测量无反应性充血的过去发表的报告摘要。
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always"><tbody>
<tr>
<td>参考</td>
			<td>研究人口</td>
			<td>衰减%</td>
		</tr>
<tr>
<td rowspan="2">尼尔森 MD, j Physiol, 2015</td>
			<td>健康</td>
			<td>-57</td>
		</tr>
<tr>
<td>贝克肌肉萎缩症</td>
			<td>-13</td>
		</tr>
<tr>
<td rowspan="2">Vongpatanasin, j Physiol, 2011</td>
			<td>健康</td>
			<td>-93</td>
		</tr>
<tr>
<td>高血压</td>
			<td>-14</td>
		</tr>
<tr>
<td rowspan="2">Fadel, j Physiol, 2004</td>
			<td>绝经前</td>
			<td>-84</td>
		</tr>
<tr>
<td>绝经后</td>
			<td>-19</td>
		</tr>
<tr>
<td rowspan="2">砂光机, pna, 2000</td>
			<td>健康</td>
			<td>-74</td>
		</tr>
<tr>
<td>杜氏肌营养不良</td>
			<td>. + 7</td>
		</tr>
<tr>
<td rowspan="2">尼尔森 MD,神经病学, 2014</td>
			<td>健康</td>
			<td>-54</td>
		</tr>
<tr>
<td>杜氏肌营养不良</td>
			<td>-7</td>
		</tr>
<tr>
<td rowspan="2">价格,高血压, 2013</td>
			<td>高血压前期治疗</td>
			<td>-52</td>
		</tr>
<tr>
<td>高血压后 Nebivolol 治疗</td>
			<td>-97</td>
		</tr>
<tr>
<td rowspan="2">汉森, j. 杂志。投资., 1996</td>
			<td>20% MVC 的健康运动</td>
			<td>-92</td>
		</tr>
<tr>
<td>30% MVC 的健康运动</td>
			<td>-125</td>
		</tr>
</tbody></table>表 3: 通过近红外线光谱学, 结合下体负压和手柄运动, 对以往发表的报告进行了总结, 以评估功能性 sympatholysis。

Watch this Scientific Journal Video about Skeletal Muscle Neurovascular Coupling, Oxidative Capacity, and Microvascular Function with 'One Stop Shop' Near-infrared Spectroscopy at JoVE.com

Skeletal Muscle Neurovascular Coupling, Oxidative Capacity, and Microvascular Function with 'One Stop Shop' Near-infrared Spectroscopy

"一站式" 近红外光谱对骨骼肌神经血管的耦合、氧化能力及微血管功能的作用

在这里, 我们描述了一个简单的, 非侵入性的方法, 使用近红外光谱评估反应性充血, 神经血管耦合和骨骼肌氧化能力的单一诊所或实验室访问。

Exercise represents a major hemodynamic stress that demands a highly coordinated neurovascular response in order to match oxygen delivery to metabolic ...

skeletal-muscle-neurovascular-coupling-oxidative-capacity

Universidad San Sebastian

Research

JoVE Journal

Medicine

12.5K 次观看.  University of Texas at Arlington. 在这里, 我们描述了一个简单的, 非侵入性的方法, 使用近红外光谱评估反应性充血, 神经血管耦合和骨骼肌氧化能力的单一诊所或实验室访问。

视频: Skeletal Muscle Neurovascular Coupling, Oxidative Capacity, and Microvascular Function with 'One Stop Shop' Near-infrared Spectroscopy

Myo-mechanical Analysis of Isolated Skeletal Muscle

To assess the in vivo effects of therapeutic interventions for the treatment of muscle disease 1,2,3, quantitative methods are needed that measure force generation and fatigability in treated muscle. We describe a detailed approach to evaluating myo-mechanical properties in freshly explanted hindlimb muscle from the mouse. We describe the atraumatic harvest of mouse extensor digitorum longus muscle, mounting the muscle in a muscle strip myograph (Model 820MS; Danish Myo Technology), and the measurement of maximal twitch and tetanic tension, contraction time, and half-relaxation time, using a square pulse stimulator (Model S48; Grass Technologies). Using these measurements, we demonstrate the calculation of specific twitch and tetanic tension normalized to muscle cross-sectional area, the twitch-to-tetanic tension ratio, the force-frequency relationship curve and the low frequency fatigue curve 4. This analysis provides a method for quantitative comparison between therapeutic interventions in mouse models of muscle disease 1,2,3,5, as well as comparison of the effects of genetic modification on muscle function 6,7,8,9.

To assess the in vivo effects of therapeutic interventions for muscle disease, methods are needed to quantitate force generation and fatigability in treated muscle. We detail an approach to evaluating myo-mechanical properties in explanted mouse hindlimb muscle. This analysis provides a robust approach to quantitating the effects of genetic modification on muscle function, as well as comparison of therapies in mouse models of muscle disease.

离体骨骼肌肌的力学分析

To assess the in vivo effects of therapeutic interventions for the treatment of muscle disease 1,2,3, quantitative methods are needed that measure force ...

科研

医学

In Vivo Canine Muscle Function Assay

We describe a minimally-invasive and reproducible method to measure canine pelvic limb muscle strength and muscle response to repeated eccentric 
contractions. The pelvic limb of an anesthetized dog is immobilized in a stereotactic frame to align the tibia at a right angle to the femur. Adhesive wrap affixes the 
paw to a pedal mounted on the shaft of a servomotor to measure torque. Percutaneous nerve stimulation activates pelvic limb muscles of the paw to either push (extend) or 
pull (flex) against the pedal to generate isometric torque. Percutaneous tibial nerve stimulation activates tibiotarsal extensor muscles. Repeated eccentric (lengthening) 
contractions are induced in the tibiotarsal flexor muscles by percutaneous peroneal nerve stimulation. The eccentric protocol consists of an initial isometric contraction 
followed by a forced stretch imposed by the servomotor. The rotation effectively lengthens the muscle while it contracts, e.g., an eccentric contraction. During 
stimulation flexor muscles are subjected to an 800 msec isometric and 200 msec eccentric contraction. This procedure is repeated every 5 sec. To avoid fatigue, 4 min rest 
follows every 10 contractions with a total of 30 contractions performed.

In Vivo Canine Muscle Function Assay

We describe a minimally-invasive and painless method to measure canine hindlimb muscle strength and muscle response to repeated eccentric contractions.

在犬体内的肌肉功能测定

We describe a minimally-invasive and reproducible method to measure canine pelvic limb muscle strength and muscle response to repeated eccentric 
...

Functional Near Infrared Spectroscopy of the Sensory and Motor Brain Regions with Simultaneous Kinematic and EMG Monitoring During Motor Tasks

There are several advantages that functional near-infrared spectroscopy (fNIRS) presents in the study of the neural control of human movement. It is relatively flexible with respect to participant positioning and allows for some head movements during tasks. Additionally, it is inexpensive, light weight, and portable, with very few contraindications to its use. This presents a unique opportunity to study functional brain activity during motor tasks in individuals who are typically developing, as well as those with movement disorders, such as cerebral palsy. An additional consideration when studying movement disorders, however, is the quality of actual movements performed and the potential for additional, unintended movements. Therefore, concurrent monitoring of both blood flow changes in the brain and actual movements of the body during testing is required for appropriate interpretation of fNIRS results. Here, we show a protocol for the combination of fNIRS with muscle and kinematic monitoring during motor tasks. We explore gait, a unilateral multi-joint movement (cycling), and two unilateral single-joint movements (isolated ankle dorsiflexion, and isolated hand squeezing). The techniques presented can be useful in studying both typical and atypical motor control, and can be modified to investigate a broad range of tasks and scientific questions.

Monitoring brain activity during upright motor tasks is of great value when investigating the neural source of movement disorders. Here, we demonstrate a protocol that combines functional near infrared spectroscopy with continuous monitoring of muscle and kinematic activity during 4 types of motor tasks.

感觉和运动脑区与运动同步和肌电图监测功能近红外光谱在运动任务

There are several advantages that functional near-infrared spectroscopy (fNIRS) presents in the study of the neural control of human movement. It is ...

行为学

Skeletal Muscle Gender Dimorphism from Proteomics

Gross contraction in skeletal muscle is primarily determined by a relatively small number of contractile proteins, however this tissue is also remarkably adaptable to environmental factors1 such as hypertrophy by resistance exercise and atrophy by disuse. It thereby exhibits remodeling and adaptations to stressors (heat, ischemia, heavy metals, etc.)2,3. Damage can occur to muscle by a muscle exerting force while lengthening, the so-called eccentric contraction4. The contractile proteins can be damaged in such exertions and need to be repaired, degraded and/or resynthesized; these functions are not part of the contractile proteins, but of other much less abundant proteins in the cell. To determine what subset of proteins is involved in the amelioration of this type of damage, a global proteome must be established prior to exercise5 and then followed subsequent to the exercise to determine the differential protein expression and thereby highlight candidate proteins in the adaptations to damage and its repair. Furthermore, most studies of skeletal muscle have been conducted on the male of the species and hence may not be representative of female muscle. 
In this article we present a method for extracting proteins reproducibly from male and female muscles, and separating them by two-dimensional gel electrophoresis followed by high resolution digital imaging6. This provides a protocol for spots (and subsequently identified proteins) that show a statistically significant (p &lt; 0.05) two-fold increase or decrease, appear or disappear from the control state. These are then excised, digested with trypsin and separated by high-pressure liquid chromatography coupled to a mass spectrometer (LC/MS) for protein identification (LC/MS/MS)5. This methodology (Figure 1) can be used on many tissues with little to no modification (liver, brain, heart etc.).

A straight-forward set of methods to isolate and determine the identity of the most abundant proteins expressed in skeletal muscle. About 800 spots are discerned on a two-dimensional gel from 10 mg muscle; this allows for the determination of gender-specific protein expression. These methods will give equivalent results in most tissues.

骨骼肌蛋白质组学性别异形

Gross contraction in skeletal muscle is primarily determined by a relatively small number of contractile proteins, however this tissue is also remarkably ...

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 ...

Quantitative Magnetic Resonance Imaging of Skeletal Muscle Disease

Quantitative magnetic resonance imaging (qMRI) describes the development and use of MRI to quantify physical, chemical, and/or biological properties of living systems. Neuromuscular diseases often exhibit a temporally varying, spatially heterogeneous, and multi-faceted pathology. The goal of this protocol is to characterize this pathology using qMRI methods. The MRI acquisition protocol begins with localizer images (used to locate the position of the body and tissue of interest within the MRI system), quality control measurements of relevant magnetic field distributions, and structural imaging for general anatomical characterization. The qMRI portion of the protocol includes measurements of the longitudinal and transverse relaxation time constants (T1 and T2, respectively). Also acquired are diffusion-tensor MRI data, in which water diffusivity is measured and used to infer pathological processes such as edema. Quantitative magnetization transfer imaging is used to characterize the relative tissue content of macromolecular and free water protons. Lastly, fat-water MRI methods are used to characterize fibro-adipose tissue replacement of muscle. In addition to describing the data acquisition and analysis procedures, this paper also discusses the potential problems associated with these methods, the analysis and interpretation of the data, MRI safety, and strategies for artifact reduction and protocol optimization.

Neuromuscular diseases often exhibit a temporally varying, spatially heterogeneous, and multi-faceted pathology. The goal of this protocol is to characterize this pathology using non-invasive magnetic resonance imaging methods.

骨骼肌疾病的定量磁共振成像

Quantitative magnetic resonance imaging (qMRI) describes the development and use of MRI to quantify physical, chemical, and/or biological properties of ...

Phosphorus-31 Magnetic Resonance Spectroscopy: A Tool for Measuring In Vivo Mitochondrial Oxidative Phosphorylation Capacity in Human Skeletal Muscle

Skeletal muscle mitochondrial oxidative phosphorylation (OXPHOS) capacity, which is critically important in health and disease, can be measured in vivo and noninvasively in humans via phosphorus-31 magnetic resonance spectroscopy (31PMRS). However, the approach has not been widely adopted in translational and clinical research, with variations in methodology and limited guidance from the literature. Increased optimization, standardization, and dissemination of methods for in vivo 31PMRS would facilitate the development of targeted therapies to improve OXPHOS capacity and could ultimately favorably impact cardiovascular health. 31PMRS produces a noninvasive, in vivo measure of OXPHOS capacity in human skeletal muscle, as opposed to alternative measures obtained from explanted and potentially altered mitochondria via muscle biopsy. It relies upon only modest additional instrumentation beyond what is already in place on magnetic resonance scanners available for clinical and translational research at most institutions. In this work, we outline a method to measure in vivo skeletal muscle OXPHOS. The technique is demonstrated using a 1.5 Tesla whole-body MR scanner equipped with the suitable hardware and software for 31PMRS, and we explain a simple and robust protocol for in-magnet resistive exercise to rapidly fatigue the quadriceps muscle. Reproducibility and feasibility are demonstrated in volunteers as well as subjects over a wide range of functional capacities.

Phosphorus-31 Magnetic Resonance Spectroscopy: A Tool for Measuring In Vivo Mitochondrial Oxidative Phosphorylation Capacity in Human Skeletal Muscle

This work demonstrates the feasibility of an in vivo phosphorus-31 magnetic resonance spectroscopy (31PMRS) technique to quantify mitochondrial oxidative phosphorylation (OXPHOS) capacity in human skeletal muscle.

磷31磁共振波谱分析:一种测量工具<em&gt;在体内</em&gt;线粒体氧化磷酸化能力人骨骼肌

Skeletal muscle mitochondrial oxidative phosphorylation (OXPHOS) capacity, which is critically important in health and disease, can be measured in vivo ...

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.

使用混合近红外漫反射光谱对重症监护的微血管氧合和反应性充血进行无创监测

The detection of levels of impairment in microvascular oxygen consumption and reactive hyperemia is vital in critical care. However, there are no ...

Using Near-Infrared Spectroscopy Wearable Devices to Identify Central Versus Peripheral Limitations During Exercise

The gold standard to assess the aerobic capacity in physically active subjects and athletes is the maximal oxygen consumption test (VO2&#8211;max), which involves analysis of exhaled&#8211;gases and cardiorespiratory variables obtained via the breath-by-breath method in an ergospirometer during an incremental exercise. However, this method cannot elucidate metabolic changes at the muscular level. Near-infrared spectroscopy (NIRS) has emerged as a valuable technology to evaluate local oxygen levels (Tissular Saturation Index, TSI) by quantifying the concentrations of oxygenated (O2-Hb) and deoxygenated (H-Hb) hemoglobin in the microvasculature of tissues. NIRS applications extend to respiratory and locomotor muscles, assessing metabolic changes associated with the cost of breathing (COB) and peripheral workload, respectively. Additionally, cerebral regions, such as the prefrontal cortex, have been explored with NIRS technology to assess physiological changes related to cognitive demand associated with planning or ideation of motor tasks linked to sports performance. Thus, by analyzing exercise-induced changes (D) in O2-Hb, H-Hb, and TSI, it is possible to identify central and peripheral exercise limitations, particularly when endurance training is the main component of physical fitness (e.g., running, cycling, triathlon, etc.). Addressing these factors is paramount for coaches and exercise physiologists to optimize athletic performance, incorporating training strategies focused on the primary exercise-limiting factors. This study outlines a protocol for utilizing wearables devices equipped with NIRS technology to analyze exercise changes in TSI, O2-Hb, and H-Hb, alongside cardiorespiratory variables typically registered in athletes during VO2&#8211;max tests. This approach offers a comprehensive method for identifying the primary systems involved in stopping exercise progression and sports performance improvement.

This protocol integrates near-infrared spectroscopy (NIRS) technology to assess localized hematological and oxygenation changes at the prefrontal cortex, respiratory (m.Intercostales), and locomotor (m.Vastus Lateralis) muscles during cardiopulmonary exercise testing, enabling the identification of central and peripheral limiting factors affecting exercise performance.

使用近红外光谱可穿戴设备识别运动期间的中枢限制与外周限制

The gold standard to assess the aerobic capacity in physically active subjects and athletes is the maximal oxygen consumption test (VO2&#8211;max), which ...

优化 NIRS 以评估下肢血管功能

Near-Infrared Spectroscopy During Reactive Hyperemia for the Assessment of Lower Limb Vascular Function

Vascular diseases of the lower limb contribute substantially to the&#160;global burden of cardiovascular disease and comorbidities such as diabetes. Importantly, microvascular dysfunction can occur prior to, or alongside, macrovascular pathology, and both potentially contribute to patient symptoms and disease burden. Here, we describe a non-invasive approach using near-infrared spectroscopy (NIRS) during reactive hyperemia, which provides a standardized assessment of lower limb vascular (dys)function and a potential method to evaluate the efficacy of therapeutic interventions. Unlike alternative methods, such as contrast-enhanced ultrasound, this approach does not require venous access or sophisticated image analysis, and it is inexpensive and less operator-dependent. This description of the NIRS method includes representative results and standard terminology alongside the discussion of measurement considerations, limitations, and alternative methods. Future application of this work will improve standardization of vascular research design, data collection procedures, and harmonized reporting, thereby enhancing translational research outcomes in the areas of lower limb vascular (dys)function, disease, and treatment.

作者聚焦：通过新型干预措施和 NIRS 技术增强心血管疾病的血管功能和体能

Here, we describe a non-invasive approach using near-infrared spectroscopy to assess reactive hyperemia in the lower limb. This protocol provides a standardized assessment of vascular and microvascular responsiveness that may be used to determine the presence of vascular dysfunction as well as the efficacy of therapeutic interventions.

反应性充血期间的近红外光谱评估下肢血管功能 

Vascular diseases of the lower limb contribute substantially to the&#160;global burden of cardiovascular disease and comorbidities such as diabetes. ...