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Development of a broadband multi-channel NIRS system for quantifying absolute concentrations of hemoglobin derivatives and reduced scattering coefficients.

机译：宽带多通道NIRS系统的开发，用于量化血红蛋白衍生物的绝对浓度和降低的散射系数。

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摘要

Near infrared spectroscopy (NIRS) has been widely applied to investigate hemoglobin oxygenations of muscles, brain and breast tumors. Steady state reflectance techniques developed previously have been restricted to determination of relative concentrations. To overcome these limitations, this dissertation describes the development, validation and applications of broadband, steady-state, optical spectroscopic systems and algorithms to quantify absolute concentrations of hemoglobin derivatives and reduced light scattering coefficients using (1) thin optical probes with small (100 mum--1 mm) source-detector separations and (2) a large separation ( 4 cm) probe. A recently developed mathematical model by Zonios and Dimou for reflectance at small source-detector separations was used to develop techniques to quantify chromophore concentrations and light scattering coefficients (Chap. 2). Blood-intralipid phantom models were used to determine empirical coefficients to model reflectance spectra. This technique was further applied to quantify hemodynamic changes during formalin-induced pain behaviors in rats (Chap. 3).;To overcome limitations in penetration depth and investigated tissue volume, another approach to quantify concentrations of chromophores in tissues at large source-detector separations was also developed. This novel approach uses the process of second differential spectroscopy to quantify concentrations of deoxygenated hemoglobin with respect to the tissue water content. Based on such quantification, an adaptation of the ant colony optimization algorithm was utilized to quantify absolute concentrations of other constituent tissue chromophores. The developed techniques were validated with the reflectance measurements from blood-intralipid phantoms and further applied to monitoring of ex vivo human prostate lesions and of rat brain tumor growth in vivo (Chap. 4).;In the second stage of my doctoral development, a multi-channel, broadband, steady-state, NIRS imaging system was developed to determine spatial distributions of hemoglobin concentrations and reduced light scattering coefficients. The imager was calibrated with laboratory phantoms to eliminate deterministic instrumentation bias of CCD-spectrometers, optical fibers, and multiplexer channels. Calibration procedures also include determinations of the source strength and boundary coefficients in order to obtain accurate image reconstructions. A multi-wavelength, spectrally constrained reconstruction algorithm was developed to obtain tomographic maps of hemoglobin derivative concentrations and reduced scattering coefficients, using laboratory tissue phantoms. The developed imaging system and reconstruction algorithms were validated with both static and dynamic multi-tube phantoms.
机译：近红外光谱（NIRS）已被广泛用于研究肌肉，大脑和乳腺肿瘤的血红蛋白氧合。先前开发的稳态反射技术仅限于确定相对浓度。为了克服这些限制，本文描述了宽带，稳态，光学光谱系统和算法的开发，验证和应用，这些系统和算法使用（1）小（100微米）的细光学探针来定量血红蛋白衍生物的绝对浓度和降低的光散射系数-1毫米）源-探测器间距和（2）大间距（<4厘米）探头。 Zonios和Dimou最近开发的用于在小源-检测器分离时的反射率的数学模型用于开发量化发色团浓度和光散射系数的技术（第2章）。血脂模型用于确定经验系数以建立反射光谱。这项技术进一步应用于量化在福尔马林引起的大鼠疼痛行为过程中的血流动力学变化（第3章）；为了克服穿透深度的限制和研究组织体积，在大的源-检测器分离下量化组织中生色团浓度的另一种方法也被开发了。这种新颖的方法使用二次差分光谱法来定量相对于组织含水量的脱氧血红蛋白浓度。基于这样的定量，采用蚁群优化算法的适应方法来定量其他组成组织生色团的绝对浓度。所开发的技术已通过血脂模型的反射率测量得到验证，并进一步用于监测离体人类前列腺病变和体内大鼠脑肿瘤的生长（第4章）。开发了多通道，宽带，稳态NIRS成像系统，以确定血红蛋白浓度的空间分布和降低的光散射系数。用实验室模型对成像仪进行校准，以消除CCD光谱仪，光纤和多路复用器通道的确定性仪器偏差。校准程序还包括确定光源强度和边界系数，以获得准确的图像重建。使用实验室组织体模，开发了一种多波长，光谱受限的重建算法，以获取血红蛋白衍生物浓度和降低的散射系数的层析成像图。所开发的成像系统和重建算法已通过静态和动态多管体模验证。

著录项

  • 作者

    Kashyap, Dheerendra.;

  • 作者单位

    The University of Texas at Arlington.;

  • 授予单位 The University of Texas at Arlington.;
  • 学科 Engineering Biomedical.;Biophysics Medical.
  • 学位 Ph.D.
  • 年度 2007
  • 页码 334 p.
  • 总页数 334
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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