Development of a Hyperspectral FD-NIRS Device for Muscle Physiology

摘要 近红外光谱(NIRS)是一种测量生色团的非侵入性光学技术 组织中的浓度，包括血红蛋白、肌红蛋白、水、脂类和细胞色素C氧化酶。连续式 WAVE(CW-)近红外光谱系统被广泛使用，但仅限于测量生色团的变化 由于未知的原因，在报告绝对浓度方面的定量准确性较低 与光在组织中的扩散有关的路径长度因子。频域(FD-)近红外光谱是它的一种变体 使用调幅光并测量光的幅度和相位的方法 通过组织以提供对基线光学性质的更多定量估计。但是，当前 由于成本和复杂性，FD-NIRS系统仅限于几个光学波长 调制电路。在这个项目中，我们计划开发一种新型的高光谱FD-NIRS系统，该系统使用 宽带白光光源和ccd光谱仪探测系统。这一制度的独特创新之处 是使用电光调制器(EOM)，它将用于直接调制光，而不是 依靠激光二极管的电调制。将使用两个设备来实现外差减速 这些MHz信号用于CCD检测。这种方法将是一种更简单、更具成本效益的方式 与之前版本的CW相比，增加了系统使用的波长数量和范围- 和FD-NIRS系统。该设备将改进在广泛范围内收集近红外光谱的方式 申请。这项研究的目的是： 目的1.构建高光谱FD-NIRS装置并表征其灵敏度和噪声特性 乐器。 目的2.研究CW-NIRS和FD-NIRS测量的敏感性和特异性 用蒙特卡罗技术观察真实肌肉结构对光子的影响 迁移。 目的3.表征生理化合物测量的敏感性和特异性 在体模中使用该装置，并与蒙特卡罗模拟结果进行比较。 这项建议的R03研究将开发这一独特的系统，并允许我们应用这些先进的近红外光谱 未来肌肉生理学研究中的技术，包括损伤风险评估，衰老和 糖尿病，以及其他各种工作。

ABSTRACT Near-infrared spectroscopy (NIRS) is a non-invasive optical technique to measure chromophore concentrations in tissue including hemoglobin, myoglobin, water, lipid, and cytochrome C oxidase. Continuous wave (CW-) NIRS systems are widely used but are limited to the measurement of changes in chromophore concentrations and have low quantitative accuracy in reporting absolute concentrations due to the unknown pathlength factors related to the diffusion of light in tissue. Frequency-domain (FD-) NIRS is a variation of this method that uses amplitude modulated light and the measurement of the amplitude and phase of the light passing through tissue to provide more quantitative estimates of baseline optical properties. However, current FD-NIRS systems are limited to only a few optical wavelengths due to the cost and complexity of these modulation circuits. In this project, we propose to develop a novel hyperspectral FD-NIRS system, which uses a broadband white light source and CCD spectrometer detection system. The unique innovation of this system is the use of electro-optical modulators (EOMs), which will be used to directly modulate the light rather than relying on electrical modulation of laser diodes. Two devices will be used to enable heterodyne downshifting of these MHz signals for CCD detection. This approach will be a much simpler and more cost effective way to increase the number and range of wavelengths used by the system in comparison to previous versions of CW- and FD-NIRS systems. This device will improve the way in which NIRS is collected across a wide range of applications. The aims of this study are: Aim 1. Construct a hyperspectral FD-NIRS device and characterize sensitivity and noise properties of the instrument. Aim 2. Investigate the sensitivity and specificity of CW- and FD-NIRS measurements in simulated muscle tissue using Monte Carlo techniques to look at the effect of realistic muscle structure on photon migration. Aim 3. Characterize the sensitivity and specificity of the measurement of physiological compounds using the device in phantoms and compare with Monte Carlo simulation results. This proposed R03 study will develop this unique system and allow us to apply these advanced NIRS techniques in future studies of muscle physiology including injury risk assessment, the impact of aging and diabetes, among various other work.