采用氧合血红蛋白吸收带的漫反射光谱比率R540/R575检测人胃癌

采用氧合血红蛋白吸收带的平均漫反射光谱比率(R540/R575)对离体的人正常胃、未分化胃腺癌、胃鳞状细胞癌和低分化胃腺癌的上皮粘膜组织进行鉴别诊断.实验采用带积分球附件的分光光度计测量组织样品在400 nm～600 nm的漫反射光谱.实验结果表明,在相同的波长范围内,人的未分化胃腺癌、胃鳞状细胞癌和低分化胃腺癌的上皮粘膜组织的漫反射光的强度较人正常胃的上皮粘膜组织的漫反射光强度要显著地低的,尤其是在氧合血红蛋白的吸收带540 nm和575 nm波长处,人正常胃、未分化胃腺癌、胃鳞状细胞癌和低分化胃腺癌的上皮粘膜组织的平均漫反射光谱比率分别是(94.25±2.4)%,(109±3.0)%,(1032±2.8)%和(98.6±2.6)%.     

人膀胱粘膜/粘膜下层组织病变致组织漫反射光谱的变化

研究了人正常膀胱和浅表性膀胱癌的粘膜/粘膜下层组织在300～900nm光谱范围的漫反射光谱特性及其差异,实验采用带积分球附件的分光光度计获取组织的漫反射光谱.结果表明,在300～900 nm,正常膀胱的粘膜/粘膜下层对任一个波长的漫反射率都明显地较癌变的粘膜/粘膜下层对相应波长的要大.正常膀胱的粘膜/粘膜下层的漫反射光谱的峰分别在370 nm、520 nm、550 nm和660nm,其峰值分别为52.4%、60.7%、56.1%和75.5%.而癌变的粘膜/粘膜下层的漫反射光谱的峰分别在320 nm、520 nm、550 nm和660 nm,其峰值分别为43.7%、33.4%、30.6%和70.2%.正常膀胱的粘膜/粘膜下层的漫反射光谱在370 nm处有一个峰,而癌变的粘膜/粘膜下层的漫反射光谱在370 nm处没有峰,320 nm处有一个峰.而正常膀胱的粘膜/粘膜下层的漫反射光谱在320 nm处没有峰.膀胱的粘膜/粘膜下层病变导致组织的漫反射光谱在520 nm、550 nm和660 nm处的峰的峰值分别减小了45.0%、45.5%和7.02%.说明膀胱的粘膜/粘膜下层病变导致组织的组分和结构尤其足组织中的氧合血红蛋白和去氧血红蛋白的含量发生了明显的改变.     

漫反射光谱技术对文物保护及相关问题的研究

应用自行研制的光导纤维反射分光光度计,研究了漫反射光谱技术在文物保护研究中的应用。主要工作包括： (1)通过比较待测颜料和标准颜料反射光谱曲线的形状和特征反射峰或一阶导数峰的位置,实现对彩绘文物颜料的分析鉴定。(2)用漫反射光谱技术监测金属表面状态的变化。文中通过对铜及其锈蚀产物漫反射光谱的研究得到了铜表面的一些信息,可见漫反射光谱技术对金属表面状态的研究具有特殊的功能。(3)通过研究文物保护修复材料的反射光谱特性,指导人们选择适宜的材料。作者的研究证实了漫反射光谱法是一种新的文物保护研究技术,具有简便、快捷和不损坏文物的特点,该工作使漫反射光谱技术成为文物保护研究的一种新的检测手段,同时也为漫反射光谱分析开辟了新的研究应用领域。     

菊苣体外干物质消化率近红外分析模型的建立

菊苣(Cichorium intybus L.)是一种新型的高产优质饲用牧草,具有极大的推广利用价值。体外干物质消化率(in vitro dry matter digestibility,IVDMD)是评价饲草营养价值的重要指标之一。建立菊苣体外干物质消化率的NIRS定量分析模型的研究,采集了72个品种、不同基因型、不同生长发育时期的204个菊苣地上部分为样品,应用傅里叶变换近红外漫反射光谱技术,通过采用不同的回归算法,比较不同的光谱范围和光谱预处理方法,建立了8个菊苣体外干物质消化率(IVDMD)的近红外漫反射光谱校正模型,从中选出最佳参数的校正模型。其校正决定系数(R2cal)和外部验证决定系数(R2val)分别为0.953 17和0.904 55,校正标准差(RMSEC)和预测标准差(RMSEP)分别为1.977 99%和2.008 82%,预测值与化学值间的相关系数(r)达0.951 08。结果表明,利用近红外漫反射光谱法来测定菊苣体外干物质消化率(IVDMD)是可行的,可为菊苣体外干物质消化率(IVDMD)的测定提供快速的分析测定方法。     

近红外漫反射光谱法预测紫花苜蓿草颗粒营养价值

研究旨在探讨利用紫花苜蓿草颗粒样品的近红外漫反射光谱信息,建立能够预测其营养价值的校正模型。采集22份全株草颗粒、19份茎颗粒、19份叶颗粒共60份紫花苜蓿草颗粒样品,其中建模样品45份,检验样品15份。利用傅里叶变换近红外漫反射光谱技术(FT-NIRS)采集各实验样品的近红外漫反射光谱,运用偏最小二乘法(PLS)建立了紫花苜蓿草颗粒粗蛋白(CP)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)含量的预测模型。3个预测模型的校正模型建模效果均较好,其交叉检验相关系数(R_CV)为0.964 10～0.968 87,交互验证的残差均方根(RMSECV)为0.80%～2.59%。用15个检验样品对模型进行外部检验,预测相关系数(r)为0.966 9～0.974 3,外部验证的残差均方根(RMSEP)为0.85%～2.07%。所建模型的交叉检验和外部检验RPD均大于3,表明近红外光谱分析技术可以准确地预测紫花苜蓿草颗粒的营养价值。     

中草药植物白光漫反射光谱研究

测定了 5 7种中草药植物的药用部分的白光漫反射光谱 ,与传统的紫外分光光度法及红外分光光度法相比 ,这种测定方法不用截取样品 ,可作无损检测 ,且测定过程简便。从测定结果发现 ,这些白光漫反射光谱都具有可作识别的特征峰 ,显然中草药的白光漫反射光谱可作为中草药鉴别的一种辅助方法。从测定的白光漫反射光谱中 ,还发现药用部分为地上部分的 (阳光下生长的 )在 6 5 0～ 6 90nm区间具有明显的大吸收峰 ,而药用部分为地下部分的或植物体内的 (不在阳光下生长的 ,如种子 )则没有 ,因此可利用某些中草药植物在 6 5 0～ 6 90nm区间的吸收特性用光控方法调控中草药的栽培生产 ,提高中草药的质量与产量。     

基于扩散理论的生物组织固有荧光光谱复原方法研究

组织固有荧光光谱定义为未受生物组织吸收、散射作用影响的荧光光谱,能够直接反映组织微观结构和生物化学性质信息。为了减少吸收和散射特性对组织荧光光谱的干扰,从实测的组织荧光光谱中复原更能反映组织荧光特性的组织固有荧光光谱,搭建了基于光纤探头的组织光谱测量系统,实现生物组织相同位置处的荧光光谱和漫反射光谱测量。提出运用扩散理论从实测的漫反射光谱中提取组织生理参数,包括组织中血液体积分数、血氧饱和度、黑色素含量以及波长500 nm处约化散射系数和瑞利散射在总散射中的比例,进而计算可见波段范围内的组织光学参数;然后,根据组织光学参数和实测的漫反射光谱,从实测的荧光光谱中复原得到组织固有荧光光谱。进行临床试验验证,采集受试者皮肤组织荧光光谱与组织漫反射光谱,并复原皮肤固有荧光光谱。通过复原得到的固有荧光光谱反映人体皮肤糖基化终产物积聚量,并最终用于糖尿病无创筛查。结果显示,分别使用实测的荧光光谱和复原得到的固有荧光光谱用于糖尿病筛查时,在特异性水平同为75%时,敏感性分别为69%和90%。     

涩柿可溶性单宁的可见/近红外漫反射光谱无损检测研究

旨在建立可见/近红外漫反射光谱与涩柿内部可溶性单宁之间的关系,以评价可见/近红外漫反射光谱在测量涩柿内部指标可溶性单宁的应用价值.在可见/近红外光谱区域(570～1848 nm),实验对比分析了不同数学建模算法、不同导数处理方法和不同散射及标准化处理的涩柿可溶性单宁定标模型.结果表明,应用改进偏最小二乘回归算法、一阶导处理和去散射处理所建涩柿可溶性单宁定标模型的预测性能较优,其定标交互验证相关系数(Rcv)和预测相关系数(Rp2)分别为0.722 7和0.678 5,定标交互验证均方根误差(RMSECV)和预测均方根误差(RMSEP)分别为0.148 4和0.176 3.研究表明,可见/近红外漫反射光谱对涩柿可溶性单宁的快速无损检测具有一定的可行性,但模型精度有待提高.     

采用DNA和蛋白质吸收带的Kubelka-Munk光谱函数检测人结肠腺癌

采用DNA和蛋白质吸收带的Kubelka-Munk光谱函数对人结肠腺癌进行了鉴别诊断,实验采用带积分球附件的分光光度计获取组织的漫反射光谱。结果表明：在250～650 nm,结肠上皮组织的癌变导致其上皮组织在DNA吸收带的Kubelka-Munk光谱函数f(r_∞)及其对数log[f(r_∞)]的平均值在260 nm处都有非常显著性的差异,其差异分别为218%(p＜0.05)和68.5%(p＜0.05)。结肠上皮组织的癌变导致其上皮组织在蛋白质吸收带的Kubelka-Munk光谱函数f(r_∞) 及其对数log[f(r_∞)]的平均值在280 nm处也都有非常显著性的差异,其差异分别为208%(p＜0.05)和59.0%(p＜0.05)。结肠上皮组织的癌变导致其上皮组织在β-胡罗卜素吸收带(480 nm处)的Kubelka-Munk光谱函数f(r_∞) 及其对数log[f(r_∞)]的平均值在480 nm处也都有非常显著性的差异,其差异分别为41.7%(p＜0.05)和32.9%(p＜0.05)。可见,结肠上皮组织的癌变导致其上皮组织中的DNA、蛋白质和β-胡罗卜素的含量都发生了非常显著的变化。这结论为快速、低成本、非入侵的结肠腺癌的光活检提供一些有益的参考。     

采用DNA和蛋白质吸收带的Kubelka-Munk光谱函数检测人胃癌

采用DNA和蛋白质吸收带的Kubelka-Munk光谱函数对离体的人正常胃、未分化胃腺癌、胃鳞状细胞癌和低分化胃腺癌的上皮组织进行鉴别诊断。实验采用带积分球附件的分光光度计获取组织的漫反射光谱。结果表明：在250～650 nm,人胃的上皮组织的癌变导致未分化胃腺癌、胃鳞状细胞癌和低分化胃腺癌等的上皮组织的Kubelka-Munk光谱函数f(r∞)及其对数log[f(r_∞)]的平均值在DNA吸收带(260 nm)处都有非常显著性的差异,其差异分别为68.5%(p＜0.05),146.5%(p＜0.05),282.4%(p＜0.05)和32.4%(p＜0.05),56.0%(p＜0.05),83.0%(p＜0.05)。人胃的上皮组织的癌变导致未分化胃腺癌、胃鳞状细胞癌和低分化胃腺癌等的上皮组织的Kubelka-Munk光谱函数f(r_∞)及其对数log[f(r_∞)]的平均值在蛋白质的吸收带(280 nm)处也都有非常显著性的差异,其差异分别为86.8%(p＜0.05),262.9%(p＜0.05),660.1%(p＜0.05)和34%(p＜0.05),72.2%(p＜0.05),113.5%(p＜0.05)。人胃的上皮组织的癌变导致未分化胃腺癌、胃鳞状细胞癌和低分化胃腺癌等的上皮组织的Kubelka-Munk光谱函数f(r_∞)及其对数log[f(r_∞)]的平均值在β-胡萝卜素吸收峰(480 nm)处也有着显著的差异性,其差异分别为59.5%(p＜0.05),73%(p＜0.05),258.9%(p＜0.05)和118.7%(p＜0.05),139.2%(p＜0.05),324.6%(p＜0.05)。可见,人胃上皮组织的癌变导致其DNA、蛋白质和β-胡萝卜的含量都发生了显著的变化。这结论为快速、低成本、非入侵的胃癌的光活检及鉴别诊断胃癌提供有益参考。     

Heat treatment of human esophageal tissues: Effect on esophageal cancer detection using oxygenated hemoglobin diffuse reflectance ratio

The main objective of the present work is to study the influence of heat treatment on the esophageal cancer detection using the diffuse reflectance (DR) spectral intensity ratio R540/R575 of oxygenated hemoglobin (HbO₂) absorption bands to distinguish the epithelial tissues of normal human esophagus and moderately differentiated esophageal squamous cell carcinoma (ESCC) at different heat treatment temperature of 20, 37, 42, 50, and 60°C, respectively. The DR spectra for the epithelial tissues of the normal esophagus and ESCC in vitro at different heat-treatment temperature in the wavelength range 400–650 nm were measured with a commercial optical fiber spectrometer. The results indicate that the average DR spectral intensity overall enhancement with concomitant increase of heat-treatment temperature for the epithelial tissues of normal esophagus and ESCC, but the average DR spectral intensity for the normal esophageal epithelial tissues is relatively higher than that for ESCC epithelial tissues at the same heat-treatment temperature. The mean R540/R575 ratios of ESCC epithelial tissues were always lower than that of normal esophageal epithelial tissues at the same temperature, and the mean R540/R575 ratios of the epithelial tissues of the normal esophagus and ESCC were decreasing with the increase of different heat-treatment temperatures. The differences in the mean R540/R575 ratios between the epithelial tissues of normal esophagus and ESCC were 13.33, 13.59, 11.76, and 11.11% at different heat-treatment temperature of 20, 37, 42, and 50°C, respectively. These results also indicate that the DR intensity ratio R540/R575 of the hemoglobin bands is a useful tool for discrimination between the epithelial tissues of normal esophagus and ESCC in the temperature range from room temperature to 50°C, but it was non-effective at 60°C or over 60°C.     

Oxygenated hemoglobin diffuse reflectance ratio for in vitro detection of human gastric pre-cancer

Oxygenated hemoglobin diffuse reflectance (DR) ratio (R540/R575) method based on DR spectral signatures is used for early diagnosis of malignant lesions of human gastric epithelial tissues in vitro. The DR spectra for four different kinds of gastric epithelial tissues were measured using a spectrometer with an integrating sphere detector in the spectral range from 400 to 650 nm. The results of measurement showed that the average DR spectral intensity for the epithelial tissues of normal stomach is higher than that for the epithelial tissues of chronic and malignant stomach and that for the epithelial tissues of chronic gastric ulcer is higher than that for the epithelial tissues of malignant stomach. The average DR spectra for four different kinds of gastric epithelial tissues show dips at 542 and 577 nm owing to absorption from oxygenated Hemoglobin (HbO₂). The differences in the mean R540/R575 ratios of HbO₂ bands are 6.84% between the epithelial tissues of normal stomach and chronic gastric ulcer, 14.7% between the epithelial tissues of normal stomach and poorly differentiated gastric adenocarcinoma and 22.6% between the epithelial tissues of normal stomach and undifferentiated gastric adenocarcinoma. It is evident from results that there were significant differences in the mean R540/R575 ratios of HbO₂ bands for four different kinds of gastric epithelial tissues in vitro (P < 0.01).     

Diffuse reflectance spectroscopy for monitoring diabetic foot ulcer – A pilot study

Foot ulceration due to diabetes mellitus is a major problem affecting 12–25% of diabetic subjects in their lifetime. An untreated ulcer further gets infected which causes necrosis leading to amputation of lower extremities. Early identification of risk factors and treatment for these chronic wounds would reduce health care costs and improve the quality of life for people with diabetes. Recent clinical investigations have shown that a series of factors including reduced oxygen delivery and disturbed metabolism have been observed on patients with foot ulceration due to diabetes. Also, these factors can impair the wound healing process. Optical techniques based on diffuse reflectance spectroscopy provide characteristic spectral finger prints shed light on tissue oxygenation levels and morphological composition of a tissue. This study deals with the application of diffuse reflectance intensity ratios based on oxyhemoglobin bands (R542/R580), ratios of oxy- and deoxy-hemoglobin bands (R580/R555), total hemoglobin concentration and hemoglobin oxygen saturation between normal and diabetic foot ulcer sites. Preliminary results obtained are found to be promising indicating the application of reflectance spectroscopy in the assessment of foot ulcer healing.     

近红外光谱漫反射和漫透射测量方法在玉米品种真实性鉴定中的应用研究

研究了适合进行玉米群体样品品种真实性鉴定的光谱测量方法。分别用近红外光谱仪的全波漫反射和短波漫透射测量方法采集8个玉米品种的光谱数据,对预处理后的数据做偏最小二乘分析(PLS-DA),建立8个玉米品种的仿生模式识别模型。分别统计用两种方法所测数据建立的品种识别模型对本类样品的平均正确识别率和对异类样品的平均正确拒识率,漫反射方法达到94.5%和96.71%,漫透射方法达到98.50%和98.00%,均满足玉米品种初筛所要求的精度,其中短波漫透射方法建立的模型对测试样本的平均正确识别率和拒识率分别比全波漫反射方法高出4%和1.3%。     

基于漫反射光谱的组织光学参数测量系统与方法研究

在体组织光学参数测量是生物医学光子学研究重点,不仅为人体成分无创检测、光学成像、光动力疗法等研究提供基础,并且可以快速获取人体光学参数变化,为临床诊断提供依据。研究了利用单一源探距离漫反射光谱在体测量光学参数的测量系统与反构方法。漫反射光谱测量系统由宽谱光源、高分辨光纤光谱仪及光纤探头组成,结构简单,测量方便,可准确快速测量样品漫反射光谱。在光纤探头几何形状基础上,研究了光纤收集及系统传递函数,在此基础上对反构算法进行了校正。光学参数反构算法中正向模型基于Monte Carlo以及神经网络方法,适用光学参数范围大,计算速度快;逆向算法采用主成分分析与非线性建模拟合相结合的方法,可抑制测量噪声影响。在测量系统及反构算法基础上,进行了组织仿体光学参数测量实验,结果表明,利用单一源探距离下漫反射谱,可以较为准确获取吸收系数以及约化散射系数,均方根误差分别达到4.58%以及7.92%。为保证系统测量准确性,测量波长范围应覆盖样品中所含吸收物质吸收峰范围。所研究的在体组织光学参数测量方法为人体成分无创检测及测量条件变化获取提供了基础。     

Analysis of Spectral Reflectance Using Normalization Method from Endoscopic Spectroscopy System

Objective assessment of gastrointestinal mucosal color is extremely important in the endoscopic diagnosis of digestive tract disease. In this paper, we propose a method to clarify the spectral characteristics of gastric and colon cancer. A large number of spectral reflectance data of mucous membrane are measured by the endoscopic spectroscopy system (ESS) in the National Cancer Center Hospital East, Kashiwa, Japan and the Department of Internal Medicine, Self-Defense Force Center Hospital, Tokyo, Japan. We assume that early cancer appears primarily in the spectral data of short wavelength, because it is usually present in a superficial cell where short wavelength light is scattered more strongly than long wavelength light. To identify the features in the short wavelength components, the spectral reflectance was divided by the reflectance of a long wavelength. We investigated the possibility of distinguishing early cancer from normal spectral data through statistical analysis, employing the projection axis as the mean difference between them. Early cancer and normal spectral data were projected on the projection axis, and the Student’s T-test was applied to evaluate the mean of the distribution between these data.     

接触压力作用下皮肤形变对于漫反射光谱测量影响研究

人体成分无创光谱检测过程中,测量条件特别是探头压力造成的组织形变在一定程度上影响光谱测量结果。利用物理模型与仿真方法,定量分析了探头接触压力作用下皮肤组织应变,及光学参数与漫反射光谱变化。首先,在多层皮肤组织物理复合模型基础上,结合生物组织固液两相组成特性,定量分析了压力作用下各层皮肤组织形变大小以及成分变化。该模型将皮肤力学模型简化为固态弹性结构及包含于其中的牛顿流体,利用有限元方法,分别模拟不同压力作用下多层皮肤组织应变大小及时间特性,并根据各层组织体积及水含量变化,定量计算其散射系数及吸收系数改变。然后,利用Monte Carlo方法模拟压力作用前后光在组织中传输过程,定量分析了探头压力对漫反射光谱中所包含人体成分检测有效信息的影响。实验结果表明,在光纤探头接触压力作用下,人体皮肤组织中真皮层厚度变小,自由水体积减小,引起散射特性及光子传输路径改变,使得漫反射光谱中所包含的有效光谱信息下降。该研究结果为优化人体漫反射光谱测量策略,提高测量准确性以及重复性提供了参考。     

Study of light propagation in human, rabbit and rat liver tissue by Monte Carlo simulation

Monte Carlo Simulation for light propagation in liver tissues of human and animal was done using Monte Carlo simulation. During the simulation we recorded the photon reflectance, transmittance and absorption of human, rabbit and rat liver tissues. Then their comparative studies were done. Average values of total diffuse reflectance, transmittance and absorption were calculated by the 10 simulations of 100,000 photons for these tissues at 633 nm. We found that diffuse reflectance increases as μ_s increases or g decreases and diffuse transmittance increases as μ_a or μ_s decreases, or as g increases. It is also concluded that the radially resolved diffuse reflectance of the tissues decays exponentially of second order.