C/C++ Coding for Matrix Pseudo Inverses in Clinical Near Infrared Spectroscopy

Near infrared spectroscopy is used clinically to investigate patterns of change in cerebral oxygenation. We have shown that differences reported between authors are likely the result of computer encoding errors in the manipulation of matrices. Current methods compute the inverse of a non-square matrix to derive chromophore concentration values, and solution of another non-square matrix to derive polynomial coefficients of a least squares best fit curve from which the first derivative can be used to estimate blood flow values. Encoding of these pseudo inverses involves too many nested looping steps to easily identify encoding errors. We have given C/C++ source code along with sample numerical values at the termination of each loop within the algorithm. This provides counter checking for future software development by other programmers, and also permits other investigators to report whether the software used for their experiments agrees with previously published material.     

近红外光谱技术（NIRS）在人体的应用与展望

近红外光谱技术(NIRS)在人体的应用与研究是近年来在国内外新兴的研究领域,因为其方便无创,成本低等优点,近20年来在不断发展和完善,引起大家的广泛关注。近红外光谱在700-900 mm范围内可以穿透一定深度的组织,组织内含氧血红蛋白、去氧血红蛋白对近红外光的吸收系数存在差异,经过传感器和计算机技术分析,得到组织的血氧参数。其测量参数为微动脉、微静脉和毛细血管中血液的血氧参数之加权平均,反应组织中的血氧参数,其中静脉血占主要地位,不同于普通脉搏式血氧监测仪的指端动脉血的血氧饱和度。基于近红外光谱技术的近红外组织血氧无创监测仪、功能性近红外光谱技术(f NIRS)、近红外光谱荧光技术等在临床医学,运动医学,神经生物学,认知科学,脑力疲劳,人机交互等新兴领域正发挥越来越重要作用。     

近红外光谱技术在稻米特性检测中的应用(综述)

近红外光谱技术是一种新型的检测分析技术,广泛应用于农业、林业、工业、医药以及食品等多个行业领域。文章综述近红外光谱技术在稻米特性检测中的应用概况,包括对大米淀粉、蛋白质和脂肪酸等营养物质的测定,大米糊化特性、粘稠度和食味特性的分析,水稻生长过程中氮、磷、钾和其他营养元素含量的分析,育种研究与品种鉴别,病害、重金属等有害物质以及其他方面。同时,指出该技术在当前检测应用中存在的一些问题,并针对目前发展趋势展望该技术的前景。     

近红外光谱法无创测量人体血红蛋白浓度

在选定的波长处(760 nm,850 nm)无创测量人体手指的漫反射光谱,利用修正的Lambert-Beer定律,实现了HbO2、Hb的绝对量估算,并由此求得血红蛋白浓度的结果。对16例志愿者进行了测量,全部男性受试者的相对误差在7.39%以下,相关系数为0.954;全部女性受试者的相对误差在7.26%以下,相关系数为0.969。     

Spectral Analysis of Event-Related Hemodynamic Responses in Functional Near Infrared Spectroscopy

The goal of this paper is to design experiments that confirm the evidence of cognitive responses in functional near infrared spectroscopy and to establish relevant spectral subbands. Hemodynamic responses of brain during single-event trials in an odd-ball experiment are measured by functional near infrared spectroscopy method. The frequency axis is partitioned into subbands by clustering the time-frequency power spectrum profiles of the brain responses. The predominant subbands are observed to confine the 0–30 mHz, 30–60 mHz, and 60–330 mHz ranges. We identify the group of subbands that shows strong evidence of protocol-induced periodicity as well as the bands where good correlation with an assumed hemodynamic response models is found.     

近红外光谱技术在运动脑功能研究中的应用

近红外光谱是一种评估生物组织氧合水平的无创性光学技术,这一技术以血液动力学原理为基础,能实时监测局部脑区的动态变化。近红外光谱作为一种客观的测量工具,在人体运动科学领域广泛运用。近红外光谱技术可用于区别体能水平、监控耐力训练和抗阻训练过程特征以及考察运动中的认知活动变化。本文综述了近红外光谱技术原理及其在抗阻运动、运动中枢疲劳和运动认知领域的运用,并对近红外光谱在运动科学领域的未来研究趋向作了分析。     

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.     

近红外光谱技术在神经外科患者脑氧和血流动力学监测中的应用研究进展

神经外科患者,尤其是脑血流自动调节功能受损的重症患者,脑氧饱和度是反应患者脑组织氧代谢情况的重要指标,实时、准确的脑氧饱和度监测方法对于指导选择有效的治疗措施和判断患者预后具有重要价值。基于血红蛋白不同氧合状态,即氧合血红蛋白(oxyhemoglobin,Hb O2),还原血红蛋白(deoxygenated hemoglobin,Hb)具有的差异性分子光谱,近红外光谱技术near infrared spectroscopy,NIRS)可监测人体局部组织氧饱和度。由于近红外射线能穿透颅骨直接获得脑组织内平均氧饱和度的特性,可协助临床实现无创持续监测脑氧饱和度的目的,近年来该技术在神经外科领域的应用研究获得了迅速发展,在颅脑创伤和其它神经外科疾病的应用研究中均取得了显著的进展,本文将对最新研究结果及其意义和未来发展方向进行综述。     

Quantification of perfusion and metabolism in an autism mouse model assessed by diffuse correlation spectroscopy and near-infrared spectroscopy

There is a need for quantitative biomarkers for early diagnosis of autism. Cerebral blood flow and oxidative metabolism parameters may show superior contrasts for improved characterization. Diffuse correlation spectroscopy (DCS) has been shown to be reliable method to obtain cerebral blood flow contrast in animals and humans. Thus, in this study, we evaluated the combination of DCS and fNIRS in an established autism mouse model. Our results indicate that autistic group had significantly (P = .001) lower (~40%) blood flow (1.16 ± 0.26) × 10⁻⁸ cm²/s), and significantly (P = .015) lower (~70%) oxidative metabolism (52.4 ± 16.6 μmol/100 g/min) compared to control group ([1.93 ± 0.74] × 10⁻⁸ cm²/s, 177.2 ± 45.8 μmol/100 g/min, respectively). These results suggest that the combination of DCS and fNIRS can provide hemodynamic and metabolic contrasts for in vivo assessment of autism pathological conditions noninvasively.     

人血清中胆固醇近红外光谱快速检测初步研究

以全自动生化分析仪测定结果为参考值,采用傅利叶变换近红外透射光谱技术,结合偏最小二乘法,建立人血清中胆固醇和甘油三酯的定标模型。利用内部交叉验证和自动优化功能对预测模型进行了优化,确定了最优建模参数。模型对人血清中胆固醇和甘油三酯定标样品集的预测值与参考值的相关系数r分别为0．9011、0．9593,预测校正标准误RMSECV分别为15．0mg／dL,21．6mg／dL。表明利用近红外光谱分析技术实现血清中胆固醇和甘油三酯快速检测是可行的。     

In Vivo Measurements of Ethanol Concentration in Rabbit Brain by 1H Magnetic Resonance Spectroscopy

In vivo 1H magnetic resonance spectroscopy was used to measure the cerebral ethanol concentration in the rabbit after both intraarterial and intragastric administration. There was good agreement between cerebral and blood ethanol concentrations at all times after administration by either route. Cerebral ethanol levels, measured using in vivo 1H spectroscopy, agreed well with those measured in perchloric acid extracts of brain, analyzed by both high-resolution 1H spectroscopy and gas chromatography. Ethanol may be useful as an indicator to measure cerebral blood flow by 1H spectroscopy and chemical shift-selective magnetic resonance imaging.     

Race‐specific differences in the phase coherence between blood flow and oxygenation: A simultaneous NIRS,white light spectroscopy and LDF study

Race‐specific differences in the level of glycated hemoglobin are well known. However, these differences were detected by invasive measurement of mean oxygenation, and their understanding remains far from complete. Given that oxygen is delivered to the cells by hemoglobin through the cardiovascular system, a possible approach is to investigate the phase coherence between blood flow and oxygen transportation. Here we introduce a noninvasive optical method based on simultaneous recordings using NIRS, white light spectroscopy and LDF, combined with wavelet‐based phase coherence analysis. Signals were recorded simultaneously for individuals in two groups of healthy subjects, 16 from Sub‐Saharan Africa (BA group) and 16 Europeans (CA group). It was found that the power of myogenic oscillations in oxygenated and de‐oxygenated hemoglobin is higher in the BA group, but that the phase coherence between blood flow and oxygen saturation, or blood flow and hemoglobin concentrations is higher in the CA group     

Diffuse optical assessment of cerebral‐autoregulation in older adults stratified by cerebrovascular risk

Diagnosis of cerebrovascular disease (CVD) at early stages is essential for preventing sequential complications. CVD is often associated with abnormal cerebral microvasculature, which may impact cerebral‐autoregulation (CA). A novel hybrid near‐infrared diffuse optical instrument and a finger plethysmograph were used to simultaneously detect low‐frequency oscillations (LFOs) of cerebral blood flow (CBF), oxy‐hemoglobin concentration ([HbO₂]), deoxy‐hemoglobin concentration ([Hb]) and mean arterial pressure (MAP) in older adults before, during and after 70° head‐up‐tilting (HUT). The participants with valid data were divided based on Framingham risk score (FRS, 1‐30 points) into low‐risk (FRS ≤15, n = 13) and high‐risk (FRS >15, n = 11) groups for developing CVD. The LFO gains were determined by transfer function analyses with MAP as the input, and CBF, [HbO₂] and [Hb] as the outputs (CA ∝ 1/Gain) . At resting‐baseline, LFO gains in the high‐risk group were relatively lower compared to the low‐risk group. The lower baseline gains in the high‐risk group may attribute to compensatory mechanisms to maintain stronger steady‐state CAs. However, HUT resulted in smaller gain reductions in the high‐risk group compared to the low‐risk group, suggesting weaker dynamic CAs. LFO gains are potentially valuable biomarkers for early detection of CVD based on associations with CAs.