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Sample records for near-infrared absorption spectroscopy

  1. Near Infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Jha, Shyam N.

    The discovery of near-infrared energy is ascribed to Herschel in the nineteenth century; the first industrial application however began in the 1950s. Initially near infrared spectroscopy (NIRS) was used only as an add-on unit to other optical devices, that used other wavelengths such as ultraviolet (UV), visible (Vis), or mid-infrared (MIR) spectrometers. In the 1980s, a single unit, stand-alone NIRS system was made available, but the application of NIRS was focused more on chemical analysis. With the introduction of light-fibre optics in the mid 1980s and the monochromator-detector developments in early 1990s, NIRS became a more powerful tool for scientific research. This optical method can be used in a number of fields of science including physics, physiology, medicine and food.

  2. The Pt2 (1,0) band of System VI in the near infrared by intracavity laser absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    O'Brien, Leah C.; O'Brien, James J.

    2011-05-01

    Intracavity laser absorption spectroscopy has been used to record rotationally resolved electronic spectra of Pt2 in the near infrared. The metal dimers were created using a 50 mm-long, platinum-lined hollow cathode plasma discharge. The observed transition at 12 937 cm-1 is identified as the (1,0) band of System VI, with state symmetries Ω = 0 - X Ω = 0.

  3. A prototype stationary Fourier transform spectrometer for near-infrared absorption spectroscopy.

    PubMed

    Li, Jinyang; Lu, Dan-feng; Qi, Zhi-mei

    2015-09-01

    A prototype stationary Fourier transform spectrometer (FTS) was constructed with a fiber-coupled lithium niobate (LiNbO3) waveguide Mach-Zehnder interferometer (MZI) for the purpose of rapid on-site spectroscopy of biological and chemical measurands. The MZI contains push-pull electrodes for electro-optic modulation, and its interferogram as a plot of intensity against voltage was obtained by scanning the modulating voltage from -60 to +60 V in 50 ms. The power spectrum of input signal was retrieved by Fourier transform processing of the interferogram combined with the wavelength dispersion of half-wave voltage determined for the MZI used. The prototype FTS operates in the single-mode wavelength range from 1200 to 1700 nm and allows for reproducible spectroscopy. A linear concentration dependence of the absorbance at λmax = 1451 nm for water in ethanolic solution was obtained using the prototype FTS. The near-infrared spectroscopy of solid samples was also implemented, and the different spectra obtained with different materials evidenced the chemical recognition capability of the prototype FTS. To make this prototype FTS practically applicable, work on improving its spectral resolution by increasing the maximum optical path length difference is in progress. PMID:26414526

  4. Near-infrared spectrum of ZrF by intracavity laser absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Harms, Jack C.; O'Brien, Leah C.; Ni, Ann; Mahkdoom, Bilal; O'Brien, James J.

    2015-04-01

    The (1, 1) band of the CΩ = 3/2 - X2Δ3/2 transition of ZrF has been recorded at high resolution using intracavity laser absorption spectroscopy. The ZrF molecules were produced using a Zr-lined copper hollow cathode sputter source with a trace amount of SF6 as a fluoride source. Molecular constants from the analysis are presented and compared with previous work.

  5. Measurement of atmospheric oxygen concentration by near-infrared absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Hoffnagle, J.

    2013-12-01

    Variations in the concentration of molecular oxygen in the atmosphere have been shown to provide important constraints on the global carbon dioxide budget (1). Numerous technologies have been explored to measure oxygen concentration, including detection of paramagnetism, gas chromatography, fuel cells, mass spectroscopy, interferometry, and absorption spectroscopy from the UV to IR. Geophysical applications impose severe demands on the precision of an oxygen concentration sensor. Oxygen variations are conventionally expressed using the delta notation applied to the O2/N2 ratio; a change of approximately 5 per meg in delta corresponds to a 1 ppm change in the atmospheric mole fraction of oxygen. Because of the large resevoir of oxygen in the atmosphere, variations of oxygen concentration are small and measurement precision on the order of several per meg is needed to extract geophysically useful information. We describe an instrument that determines the oxygen content of an atmospheric sample by using wavelength-scanned cavity ring-down spectroscopy (WS-CRDS) to measure an absorption line in the 1.2 micron band of the oxygen molecule. The CRDS method provides very high precision measurements of the optical absorption coefficient, better than 0.1 ppb/cm in 1 s measurement time, and large dynamic range. The sample temperature and pressure are stabilized to better than 5 mK and 2 Pa, respectively. The precision of the oxygen concentration measurement was characterized by the Allan variance of repeated measurements of a tank of dry air. For a 5 minute averaging period, the Allan variance of the concentration was 1 ppm. Moreover, the Allan variance continued to decline for longer time scales, reaching 0.4 ppm (corresponding to 2 per meg in delta of O2/N2) after one hour. This work demonstrates the possibility of spectroscopic measurement of molecular oxygen concentration with high precision on the time scale of minutes and good long term stability. 1. R. F. Keeling and S

  6. Hemodynamic measurements in rat brain and human muscle using diffuse near-infrared absorption and correlation spectroscopies

    NASA Astrophysics Data System (ADS)

    Yu, Guoqiang; Durduran, Turgut; Furuya, D.; Lech, G.; Zhou, Chao; Chance, Britten; Greenberg, J. H.; Yodh, Arjun G.

    2003-07-01

    Measurement of concentration, oxygenation, and flow characteristics of blood cells can reveal information about tissue metabolism and functional heterogeneity. An improved multifunctional hybrid system has been built on the basis of our previous hybrid instrument that combines two near-infrared diffuse optical techniques to simultaneously monitor the changes of blood flow, total hemoglobin concentration (THC) and blood oxygen saturation (StO2). Diffuse correlation spectroscopy (DCS) monitors blood flow (BF) by measuring the optical phase shifts caused by moving blood cells, while diffuse photon density wave spectroscopy (DPDW) measures tissue absorption and scattering. Higher spatial resolution, higher data acquisition rate and higher dynamic range of the improved system allow us to monitor rapid hemodynamic changes in rat brain and human muscles. We have designed two probes with different source-detector pairs and different separations for the two types of experiments. A unique non-contact probe mounted on the back of a camera, which allows continuous measurements without altering the blood flow, was employed to in vivo monitor the metabolic responses in rat brain during KCl induced cortical spreading depression (CSD). A contact probe was used to measure changes of blood flow and oxygenation in human muscle during and after cuff occlusion or exercise, where the non-contact probe is not appropriate for monitoring the moving target. The experimental results indicate that our multifunctional hybrid system is capable of in vivo and non-invasive monitoring of the hemodynamic changes in different tissues (smaller tissues in rat brain, larger tissues in human muscle) under different conditions (static versus moving). The time series images of flow during CSD obtained by our technique revealed spatial and temporal hemodynamic changes in rat brain. Two to three fold longer recovery times of flow and oxygenation after cuff occlusion or exercise from calf flexors in a

  7. Near-infrared photoluminescence and ligand K-edge x-ray absorption spectroscopies of AnO2Cl42-(An:u, NP, Pu)

    SciTech Connect

    Wilkerson, Marianne P; Berg, John M; Clark, David L; Conradson, Steven D; Hobart, David E; Kozimor, Stosh A; Scott, Brian L

    2008-01-01

    We have used photoluminescence and X-ray absorption spectroscopies to investigate electronic structures and metal-ligand bonding of a series of An02CI/ ' (An = U, Np, Pu) compounds. Specifically, we will discuss time-resolved near-infrared emission spectra of crystalline Cs2U(An)02C14 (An = Np and Pu) both at 23 K and 75 K, as well as chlorine Kedge X-ray absorption spectra ofCs2An02CI4 (An = U, Np).

  8. Demonstration of a portable near-infrared CH4 detection sensor based on tunable diode laser absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Zheng, Chuan-Tao; Huang, Jian-Qiang; Ye, Wei-Lin; Lv, Mo; Dang, Jing-Min; Cao, Tian-Shu; Chen, Chen; Wang, Yi-Ding

    2013-11-01

    A portable near-infrared (NIR) CH4 detection sensor based on a distributed feedback (DFB) laser modulated at 1.654 μm is experimentally demonstrated. Intelligent temperature controller with an accuracy of -0.07 to +0.09 °C as well as a scan and modulation module generating saw-wave and cosine-wave signals are developed to drive the DFB laser, and a cost effective lock-in amplifier used to extract the second harmonic signal is integrated. Thorough experiments are carried out to obtain detection performances, including detection range, accuracy, stability and the minimum detection limit (MDL). Measurement results show that the absolute detection error relative to the standard value is less than 7% within the range of 0-100%, and the MDL is estimated to be about 11 ppm under an absorption length of 0.2 m and a noise level of 2 mVpp. Twenty-four hours monitoring on two gas samples (0.1% and 20%) indicates that the absolute errors are less than 7% and 2.5%, respectively, suggesting good long term stability. The sensor reveals competitive characteristics compared with other reported portable or handheld sensors. The developed sensor can also be used for the detection of other gases by adopting other DFB lasers with different center-wavelength using the same hardware and slightly modified software.

  9. Pressure effects on the proximal heme pocket in myoglobin probed by Raman and near-infrared absorption spectroscopy.

    PubMed Central

    Galkin, O; Buchter, S; Tabirian, A; Schulte, A

    1997-01-01

    The influence of high pressure on the heme protein conformation of myoglobin in different ligation states is studied using Raman spectroscopy over the temperature range from 30 to 295 K. Photostationary experiments monitoring the oxidation state marker bands demonstrate the change of rebinding rate with pressure. While frequency changes of vibrational modes associated with rigid bonds of the porphyrin ring are <1 cm(-1), we investigate a significant shift of the iron-histidine mode to higher frequency with increasing pressure (approximately 3 cm(-1) for deltaP = 190 MPa in Mb). The observed frequency shift is interpreted structurally as a conformational change affecting the tilt angle between the heme plane and the proximal histidine and the out-of-plane iron position. Independent evidence for iron motion comes from measurements of the redshift of band III in the near-infrared with pressure. This suggests that at high pressure the proximal heme pocket and the protein are altered toward the bound state conformation, which contributes to the rate increase for CO binding. Raman spectra of Mb and photodissociated MbCO measured at low temperature and variable pressure further support changes in protein conformation and are consistent with glasslike properties of myoglobin below 160 K. PMID:9370469

  10. Near-infrared spectroscopy of dark asteroids.

    PubMed

    Barucci, M A; Lazzarin, M; Owen, T; Barbieri, C; Fulchignoni, M

    1994-08-01

    Near-infrared (J, H and K bands) spectra of nine dark asteroids (chosen among a sample of supposed primitive objects between C and D classes) have been obtained at the Mauna Kea Observatory (Hawaii) with the 2.2-m telescope using KSPEC as spectrograph. The aim of this work was to search for evidence of the presence of organic materials in these objects as found in other planetary bodies as 5145 Pholus, and in some cometary nuclei. A careful analysis of the data has revealed flat or slightly redder spectra than the solar one for all observed asteroids. No evidence of distinct absorption features was found. PMID:11539179

  11. [Application of near infrared spectroscopy (NIR) for evaluating cheese quality].

    PubMed

    Zou, Qiang; Fang, Hui; Zhang, Wei; He, Yong

    2011-10-01

    Near infrared spectrocopy, widely used in food industry, is a fast, nondestructive analysis method. Although it has been in the detection of the quality of cheese for many years, related research is few in our country. The principle of near infrared spectroscopy and the characteristics are introduced. Cheese process, shrinkage control, maturation process, shelf life, brand classification and detection of components in the application of near infrared spectroscopy are summarized. There is great potential to apply near infrared spectroscopy in cheese quality analysis. It is an urgent task to promote the application of near infrared spectroscopy and the development of China's cheese industry. PMID:22250544

  12. Interferometric near-infrared spectroscopy (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Borycki, Dawid; Kholiqov, Oybek; Chong, Shau Poh; Srinivasan, Vivek J.

    2016-03-01

    We introduce and implement interferometric near-infrared spectroscopy (iNIRS), which simultaneously extracts the optical and dynamic properties of turbid media from the analysis of the spectral interference fringe pattern. The spectral interference fringe pattern is measured using a Mach-Zehnder interferometer with a frequency swept narrow bandwidth light source such that the temporal intensity autocorrelations can be determined for all photon path lengths. This approach enables time-of-flight (TOF) resolved measurement of scatterer motion, which is a feature inaccessible in well-established diffuse correlation spectroscopy techniques. We prove this by analyzing intensity correlations of the light transmitted through diffusive fluid phantoms with photon random walks of up to 55 (approximately 110 scattering events) using laser sweep rates on the order of 100kHz. Thus, the results we present here advance diffuse optical methods by enabling simultaneous determination of depth-resolved optical properties and dynamics in highly scattering samples.

  13. Rapid, online quantification of H2S in JP-8 fuel reformate using near-infrared cavity-enhanced laser absorption spectroscopy.

    PubMed

    Dong, Feng; Junaedi, Christian; Roychoudhury, Subir; Gupta, Manish

    2011-06-01

    One of the key challenges in reforming military fuels for use with fuel cells is their high sulfur content, which can poison the fuel cell anodes. Sulfur-tolerant fuel reformers can convert this sulfur into H(2)S and then use a desulfurizing bed to remove it prior to the fuel cell. In order to optimize and verify this desulfurization process, a gas-phase sulfur analyzer is required to measure H(2)S at low concentrations (<1 ppm(v)) in the presence of other reforming gases (e.g., 25-30% H(2), 10-15% H(2)O, 15% CO, 5% CO(2), 35-40% N(2), and trace amounts of light hydrocarbons). In this work, we utilize near-infrared cavity-enhanced optical absorption spectroscopy (off-axis ICOS) to quantify H(2)S in a JP-8 fuel reformer product stream. The sensor provides rapid (2 s), highly precise (±0.1 ppm(v)) measurements of H(2)S in reformate gases over a wide dynamic range (0-1000 ppm(v)) with a low detection limit (3σ = ±0.09 ppm(v) in 1 s) and minimal cross-interferences from other present species. It simultaneously quantifies CO(2) (±0.2%), CH(4) (±150 ppm(v)), C(2)H(4) (±30 ppm(v)), and H(2)O (±300 ppm(v)) in the reformed gas for a better characterization of the fuel reforming process. Other potential applications of this technology include measurement of coal syngas and H(2)S in natural gas. By including additional near-infrared, distributive feedback diode lasers, the instrument can also be extended to other reformate species, including CO and H(2). PMID:21486070

  14. Identification of different forms of cocaine and substances used in adulteration using near-infrared Raman spectroscopy and infrared absorption spectroscopy.

    PubMed

    Penido, Ciro A F O; Pacheco, Marcos Tadeu T; Zângaro, Renato A; Silveira, Landulfo

    2015-01-01

    Identification of cocaine and subsequent quantification immediately after seizure are problems for the police in developing countries such as Brazil. This work proposes a comparison between the Raman and FT-IR techniques as methods to identify cocaine, the adulterants used to increase volume, and possible degradation products in samples seized by the police. Near-infrared Raman spectra (785 nm excitation, 10 sec exposure time) and FT-IR-ATR spectra were obtained from different samples of street cocaine and some substances commonly used as adulterants. Freebase powder, hydrochloride powder, and crack rock can be distinguished by both Raman and FT-IR spectroscopies, revealing differences in their chemical structure. Most of the samples showed characteristic peaks of degradation products such as benzoylecgonine and benzoic acid, and some presented evidence of adulteration with aluminum sulfate and sodium carbonate. Raman spectroscopy is better than FT-IR for identifying benzoic acid and inorganic adulterants in cocaine. PMID:25428273

  15. Near-infrared spectroscopy in NGC 7538

    NASA Astrophysics Data System (ADS)

    Puga, E.; Marín-Franch, A.; Najarro, F.; Lenorzer, A.; Herrero, A.; Acosta Pulido, J. A.; Chavarría, L. A.; Bik, A.; Figer, D.; Ramírez Alegría, S.

    2010-07-01

    Aims: The characterisation of the stellar population in young high-mass star-forming regions allows fundamental cluster properties like distance and age to be constrained. These are essential when using high-mass clusters as probes for conducting Galactic studies. Methods: NGC 7538 is a star-forming region with an embedded stellar population unearthed only in the near-infrared (NIR). We present the first near-infrared spectro-photometric study of the candidate high-mass stellar content in NGC 7538. We obtained H and K spectra of 21 sources with both the multi-object and long-slit modes of LIRIS at the WHT, and complement these data with subarcsecond JHKs photometry of the region using the imaging mode of the same instrument. Results: We find a wide variety of objects within the studied stellar population of NGC 7538. Our results discriminate between a stellar population associated to the H ii region, but not contained within its extent, and several pockets of more recent star formation. We report the detection of CO bandhead emission toward several sources, as well as other features indicative of a young stellar nature. We infer a spectro-photometric distance of 2.7 ± 0.5 kpc, an age spread in the range 0.5-2.2 Myr and a total mass 1.7 × 103 Msun for the older population. Based on observations made with the WHT operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.

  16. Wavelet minimum description length detrending for near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Jang, Kwang Eun; Tak, Sungho; Jung, Jinwook; Jang, Jaeduck; Jeong, Yong; Ye, Jong Chul

    2009-05-01

    Near-infrared spectroscopy (NIRS) can be employed to investigate brain activities associated with regional changes of the oxy- and deoxyhemoglobin concentration by measuring the absorption of near-infrared light through the intact skull. NIRS is regarded as a promising neuroimaging modality thanks to its excellent temporal resolution and flexibility for routine monitoring. Recently, the general linear model (GLM), which is a standard method for functional MRI (fMRI) analysis, has been employed for quantitative analysis of NIRS data. However, the GLM often fails in NIRS when there exists an unknown global trend due to breathing, cardiac, vasomotion, or other experimental errors. We propose a wavelet minimum description length (Wavelet-MDL) detrending algorithm to overcome this problem. Specifically, the wavelet transform is applied to decompose NIRS measurements into global trends, hemodynamic signals, and uncorrelated noise components at distinct scales. The minimum description length (MDL) principle plays an important role in preventing over- or underfitting and facilitates optimal model order selection for the global trend estimate. Experimental results demonstrate that the new detrending algorithm outperforms the conventional approaches.

  17. Cardiac tissue characterization using near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Singh Moon, Rajinder; Hendon, Christine P.

    2014-03-01

    Cardiac tissue from swine and canine hearts were assessed using diffuse reflectance near-infrared spectroscopy (NIRS) ex vivo. Slope measured between 800-880 nm reflectance was found to reveal differences between epicardial fat and normal myocardium tissue. This parameter was observed to increase monotonically from measurements obtained from the onset of radiofrequency ablation (RFA). A sheathe-style fiber optic catheter was then developed to allow real-time sampling of the zone of resistive heating during RFA treatment. A model was developed and used to extract changes in tissue absorption and reduced scattering based on the steady-state diffusion approximation. It was found that key changes in tissue optical properties occur during application of RF energy and can be monitored using NIRS. These results encourage the development of NIRS integrated catheters for real-time guidance of the cardiac ablation treatment.

  18. Detecting Counterfeit Antimalarial Tablets by Near-Infrared Spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Counterfeit antimalarial drugs are found in many developing countries, but it is challenging to differentiate between genuine and fakes due to their increasing sophistication. Near-infrared spectroscopy (NIRS) is a powerful tool in pharmaceutical forensics, and we tested this technique for discrim...

  19. Social Perception in Infancy: A Near Infrared Spectroscopy Study

    ERIC Educational Resources Information Center

    Lloyd-Fox, Sarah; Blasi, Anna; Volein, Agnes; Everdell, Nick; Elwell, Claire E.; Johnson, Mark H.

    2009-01-01

    The capacity to engage and communicate in a social world is one of the defining characteristics of the human species. While the network of regions that compose the social brain have been the subject of extensive research in adults, there are limited techniques available for monitoring young infants. This study used near infrared spectroscopy to…

  20. The influence of surface passivation on electronic energy relaxation dynamics of CdSe and CdSe/CdS nanocrystals studied using visible and near infrared transient absorption spectroscopy.

    PubMed

    Yi, Chongyue; Knappenberger, Kenneth L

    2015-03-19

    Charge carrier relaxation dynamics of electronically excited CdSe and CdSe/CdS core/shell nanocrystals (NCs) were studied using femtosecond time-resolved transient absorption spectroscopy, employing both visible and near-infrared (NIR) probe laser pulses. Following 400 nm excitation, the combination of visible and NIR laser probe pulses were used to determine the influence of surface passivation on electronic relaxation dynamics for nanocrystals overcoated with either organic ligands or inorganic semiconductors. In particular, low-energy NIR photons were used to isolate transient absorption signals due to either electron and hole intraband transitions. Four relaxation components were detected for CdSe NCs passivated by organic molecules: (1) picosecond hole relaxation; (2) electron deep trapping; (3) electron surface trapping; and (4) exciton radiative recombination. Based on TA data collected over a broad energy range, electron deep trapping at Se(2-) sites was suppressed for CdSe NCs passivated by inorganic (CdS) semiconducting materials. By comparing the time-dependent transient absorption data of a series of CdSe/CdS NCs with different shell thicknesses, evidence for the transition from Type-I to quasi Type-II NCs was obtained. These data illustrate the sensitivity of femtosecond time-resolved transient absorption measurements carried out over visible and near infrared probe energies for determining the influence of nanocrystal structure on electronic relaxation dynamics. PMID:25761249

  1. Birge-Sponer Estimation of the C-H Bond Dissociation Energy in Chloroform Using Infrared, Near-Infrared, and Visible Absorption Spectroscopy: An Experiment in Physical Chemistry

    ERIC Educational Resources Information Center

    Myrick, M. L.; Greer, A. E.; Nieuwland, A. A.; Priore, R. J.; Scaffidi, J.; Andreatta, Danielle; Colavita, Paula

    2008-01-01

    The fundamental and overtone vibrational absorption spectroscopy of the C-H unit in CHCl[subscript 3] is measured for transitions from the v = 0 energy level to v = 1 through v = 5 energy levels. The energies of the transitions exhibit a linearly-decreasing spacing between adjacent vibrational levels as the vibrational quantum number increases.…

  2. Near-infrared spectroscopy of renal tissue in vivo

    NASA Astrophysics Data System (ADS)

    Grosenick, Dirk; Steinkellner, Oliver; Wabnitz, Heidrun; Macdonald, Rainer; Niendorf, Thoralf; Cantow, Kathleen; Flemming, Bert; Seeliger, Erdmann

    2013-03-01

    We have developed a method to quantify hemoglobin concentration and oxygen saturation within the renal cortex by near-infrared spectroscopy. A fiber optic probe was used to transmit the radiation of three semiconductor lasers at 690 nm, 800 nm and 830 nm to the tissue, and to collect diffusely remitted light at source-detector separations from 1 mm to 4 mm. To derive tissue hemoglobin concentration and oxygen saturation of hemoglobin the spatial dependence of the measured cw intensities was fitted by a Monte Carlo model. In this model the tissue was assumed to be homogeneous. The scaling factors between measured intensities and simulated photon flux were obtained by applying the same setup to a homogeneous semi-infinite phantom with known optical properties and by performing Monte Carlo simulations for this phantom. To accelerate the fit of the tissue optical properties a look-up table of the simulated reflected intensities was generated for the needed range of absorption and scattering coefficients. The intensities at the three wavelengths were fitted simultaneously using hemoglobin concentration, oxygen saturation, the reduced scattering coefficient at 800 nm and the scatter power coefficient as fit parameters. The method was employed to study the temporal changes of renal hemoglobin concentration and blood oxygenation on an anesthetized rat during a short period of renal ischemia induced by aortic occlusion and during subsequent reperfusion.

  3. Dynamic causal modelling for functional near-infrared spectroscopy

    PubMed Central

    Tak, S.; Kempny, A.M.; Friston, K.J.; Leff, A.P.; Penny, W.D.

    2015-01-01

    Functional near-infrared spectroscopy (fNIRS) is an emerging technique for measuring changes in cerebral hemoglobin concentration via optical absorption changes. Although there is great interest in using fNIRS to study brain connectivity, current methods are unable to infer the directionality of neuronal connections. In this paper, we apply Dynamic Causal Modelling (DCM) to fNIRS data. Specifically, we present a generative model of how observed fNIRS data are caused by interactions among hidden neuronal states. Inversion of this generative model, using an established Bayesian framework (variational Laplace), then enables inference about changes in directed connectivity at the neuronal level. Using experimental data acquired during motor imagery and motor execution tasks, we show that directed (i.e., effective) connectivity from the supplementary motor area to the primary motor cortex is negatively modulated by motor imagery, and this suppressive influence causes reduced activity in the primary motor cortex during motor imagery. These results are consistent with findings of previous functional magnetic resonance imaging (fMRI) studies, suggesting that the proposed method enables one to infer directed interactions in the brain mediated by neuronal dynamics from measurements of optical density changes. PMID:25724757

  4. Noninvasive detection of gas exchange rate by near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Xu, Guodong; Mao, Zongzhen; Wang, Bangde

    2008-12-01

    In order to study the relationship among the oxygen concentration in skeletal muscle tissues and the heart rate (HR), oxygen uptake (VO2), respiratory exchange ratio (RER) during incremental running exercises on a treadmill, a near-infrared spectroscopy muscle oxygen monitor system is employed to measure the relative change in muscle oxygenation, with the heart rate, oxygen uptake, production of carbon dioxide (VCO2) and respiratory exchange ratio are recorded synchronously. The results indicate parameters mentioned above present regular changes during the incremental exercise. High correlations are discovered between relative change of oxy-hemoglobin concentration and heart rate, oxygen uptake, respiratory exchange ratio at the significance level (P=0.01). This research might introduce a new measurement technology and/or a novel biological monitoring parameter to the evaluation of physical function status, control the training intensity, estimation of the effectiveness of exercise. Keywords: near-infrared spectroscopy; muscle oxygen concentration; heart rate; oxygen uptake; respiratory exchange ratio.

  5. Near-infrared free carrier absorption in heavily doped silicon

    SciTech Connect

    Baker-Finch, Simeon C.; McIntosh, Keith R.; Yan, Di; Fong, Kean Chern; Kho, Teng C.

    2014-08-14

    Free carrier absorption in heavily doped silicon can have a significant impact on devices operating in the infrared. In the near infrared, the free carrier absorption process can compete with band to band absorption processes, thereby reducing the number of available photons to optoelectronic devices such as solar cells. In this work, we fabricate 18 heavily doped regions by phosphorus and boron diffusion into planar polished silicon wafers; the simple sample structure facilitates accurate and precise measurement of the free carrier absorptance. We measure and model reflectance and transmittance dispersion to arrive at a parameterisation for the free carrier absorption coefficient that applies in the wavelength range between 1000 and 1500 nm, and the range of dopant densities between ∼10{sup 18} and 3 × 10{sup 20} cm{sup −3}. Our measurements indicate that previously published parameterisations underestimate the free carrier absorptance in phosphorus diffusions. On the other hand, published parameterisations are generally consistent with our measurements and model for boron diffusions. Our new model is the first to be assigned uncertainty and is well-suited to routine device analysis.

  6. Quantification of the extracerebral contamination of near infrared spectroscopy signals

    NASA Astrophysics Data System (ADS)

    Mudra, R.; Niederer, P.; Keller, E.

    2005-04-01

    Recently, conventional near infrared spectroscopy (NIRS) for oxymetry has been extended with an indocyanine green (ICG) dye dilution method which allows the estimation of cerebral blood flow (CBF) and cerebral blood volume (CBV). The signal obtained through the skull is substantially influenced by extracerebral tissue. In order to quantify and eliminate extracerebral contamination of the optical density signal we have applied two approaches. Firstly, we used spatially resolved spectroscopy (SRS) with a two receiver arrangement, with separations between emitter and two receivers in distances of d1=4.0cm and d2=6.5cm. The magnitude of the determined extracerebral contamination was verified with NIRS measurements in patients after brain herniation. Intracerebral circulatory arrest was confirmed by transcerebral Doppler examination. Secondly, Monte Carlo simulation was used to simulate the light propagation through the head to quantify the extracerebral contamination of the optical density signal of NIRS. The anatomical structure is determined from 3D-magnetic resonance imaging (MRI) using a voxel resolution of 0.8 x 0.8 x 0 .8 mm3 for three different pairs of T1/T2 values. We segment the MRI data to obtain a material matrix describing the composition of skin, skull, cerebral spinal fluid (CSF), grey and white matter. Each voxel in this material matrix characterizes the light absorption and dispersion coefficient of the identified material. This material matrix is applied in the Monte Carlo simulation. With SRS an extracerebral contamination of 65% of the optical density signal is extracted, while the Monte Carlo simulation results show that the extracerebral contamination decreases from 70% to 30% with increasing emitter-receiver distance. Differences between the NIRS ICG dye dilution technique and conventional NIRS oxymetry concerning the extracerebral contamination are discussed.

  7. [Near Infrared Spectroscopy of the Cretaceous Red Beds in Inner Mongolia Dongshengmiao].

    PubMed

    Liao, Yi-peng; Cao, Jian-jin; Wu, Zheng-quan; Luo, Song-ying; Wang, Zheng-yang

    2015-09-01

    Take the cores and surface weathered soil from the Cretaceous red beds in the western of Dongshengmiao mine of Inner Mongolia and analysis with near-infrared spectroscopy. The result shows that near-infrared spectroscopy can identify mineral quickly through the characteristic absorption peaks of each group. The Cretaceous red beds in the western of Dongshengmiao mine is argillaceous cementation, it is mainly composed of quartz, feldspar, montmorillonite, illite, chlorite, muscovite etc, the mineral composition is mainly affected by the upstream source area. The clay mineral like montmorillonite water swelling and uneven drying shrinkage expands the original crack and creates new cracks, reduces its strength, which is the mainly reason of its disintegration. According to the composition of clay mineral, we speculate its weathering process is mainly physical weathering, the climate during the weathering is cold and dry. The results can not only improve the geological feature of the mining area, but also show that the near-infrared spectroscopy technology can analyze the mineral composition of soil and rock effectively on the basis of Mineral spectroscopy, which demonstrates the feasibility of the near-infrared spectroscopy can analyze minerals in soil and rock quickly, that shows the feasibility in geology study, provides new ideas for the future research of soil and rock. PMID:26669159

  8. Innovative uses of near-infrared spectroscopy in food processing.

    PubMed

    Bock, J E; Connelly, R K

    2008-09-01

    Near-infrared spectroscopy (NIRS) has experienced widespread use as an analytical tool in the last 3 decades. Researchers today are exploring ways of applying NIRS that expand beyond compositional analyses into process control. Processes such as meat tenderness evaluation, curd cutting, and dough mixing have traditionally been controlled by highly skilled master craftsmen; new NIRS research applications are demonstrating that these complex processes can be monitored and controlled in situ to produce consistent, high quality end products with online NIRS technology. Additionally, researchers also now have the potential ability to develop new nondestructive spectroscopic techniques to probe the underlying molecular evolution of these products during processing. PMID:18803725

  9. Near-infrared spectroscopy. Innovative technology summary report

    SciTech Connect

    Not Available

    1999-07-01

    A near-infrared (NIR) spectroscopy system with a remote fiber-optic probe was developed and demonstrated to measure the water content of high-level radioactive wastes from the underground storage tanks at the Hanford Site in richland Washington. The technology was developed as a cost-effective and safer alternative to the thermogravimetric analysis (TGA) technique in use as the baseline. This work was supported by the Tanks Focus Area (TFA) within the Department of Energy`s (DOE) Office of Science and Technology (OST) in cooperation with the Hanford Tank Waste Remediation System (TWRS) Program.

  10. Note: Wearable near-infrared spectroscopy imager for haired region

    NASA Astrophysics Data System (ADS)

    Kiguchi, M.; Atsumori, H.; Fukasaku, I.; Kumagai, Y.; Funane, T.; Maki, A.; Kasai, Y.; Ninomiya, A.

    2012-05-01

    A wearable optical topography system was developed that is based on near-infrared spectroscopy (NIRS) for observing brain activity noninvasively including in regions covered by hair. An avalanche photo diode, high voltage dc-dc converter, and preamplifier were placed in an electrically shielded case to be safely mounted on the head. Rubber teeth and a glass rod were prepared to clear away hair and reach the scalp. These devices realized for the first time a wearable NIRS imager for any region of the cortex. The activity in the motor cortex during finger tapping was successfully observed.

  11. Unresolved Instrumentation Problems Following Clinical Trials Using Near Infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Macnab, Andrew J.; Gagnon, Roy E.; Gagnon, Faith A.

    1998-10-01

    Near infrared spectroscopy (NIRS) clinical trials conducted over a seven year period have identified instrument engineering problems related to fiber optic failure, electromagnetic interference, chromophore algorithms, and computational software. These problems have caused confusion amongst clinicians at the bedside, rejection of large volumes of data, repeated reanalysis of data, and a significant diversion of project resources away from clinical studies and into engineering solutions. This article summarizes previously published studies and presents new data which, together, emphasize the need for improvements in NIRS technology. Instrument designers need to be aware of the need for these improvements if NIRS is to serve clinicians better during research designed to rationally define clinical management protocols.

  12. Using Visible/Near-Infrared Spectroscopy to Identify Cryptotephra Layers

    NASA Astrophysics Data System (ADS)

    McCanta, M. C.; Thomson, B. J.; Fisher, E.

    2014-12-01

    Continually accumulating marine sediments incorporate tephra layers within their depositional record that can be linked to individual explosive volcanic events. These layers can range from several meters in thickness, to discrete layers invisible to the naked eye (cryptotephra). Identification of cryptotephra layers is paramount for complete characterization of the eruptive record of a volcanic center, not just the largest eruptive events. However, cryptotephra recognition is hampered by their small volume in most drill cores. A non-destructive method to distinguish tephra layers, particularly those of a high silica nature which may not be readily detectable with magnetic methods, is visible/near-infrared (Vis/NIR) spectroscopy. The Vis/NIR region of the light spectrum contains strong absorption features due to charge-transfer absorptions in transition metals (dominated by iron) and vibration and overtone bands due to hydroxyl and water (including near 1.4 μm, 1.9 μm, and 2.2-2.5 μm). The exact position and nature of these bands provide a means to identify various carbonate-, hydroxyl-, iron-, phyllosilicate-, sulfate-, and water-bearing minerals (e.g., Pieters and Englert, 1993). We produced a series of mixtures of hemipelagic sediment and tephra which were used to identify band positions and features which strongly correlate with the presence of tephra (see figure). The addition of ~15-20 wt.% tephra to a sediment results in recognizable spectral changes. The mixture data was used to create a MATLAB program to run unknown sample analyses through. We then used an ASD FieldSpec to collect Vis/NIR data (0.39-2.5 μm) on the upper 10 m of core collected during IODP 340 (U1396C) off the coast of Montserrat at 0.5 cm resolution and applied our tephra recognition program to this data. We identified 29 potential cryptotephra layers in the 10 m analyzed. Dissolution techniques are being completed to corroborate the spectral data.

  13. Determination of in vivo skin moisture level by near-infrared reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    Saknite, Inga; Spigulis, Janis

    2015-03-01

    Near-infrared spectroscopy has a potential for noninvasive determination of skin moisture level due to high water absorption. In this study, diffuse reflectance spectra of in vivo skin were acquired in the spectral range of 900 nm to 1700 nm by using near-infrared spectrometer, optical fiber and halogen bulb light source. Absorption changes after applying skin moisturizers were analyzed over time at different body sites. Results show difference in absorption when comparing dry and normal skin. Comparison of absorption changes over time after applying moisturizer at different body sites is analyzed and discussed. Some patterns of how skin reacts to different skin moisturizers are shown, although no clear pattern can be seen due to signal noise.

  14. Using near-infrared spectroscopy for characterization of transiting exoplanets

    NASA Astrophysics Data System (ADS)

    Aronson, E.; Waldén, P.

    2015-06-01

    Context. We propose a method for observing transiting exoplanets with near-infrared high-resolution spectrometers. Aims: We aim to create a robust data analysis method for recovering atmospheric transmission spectra from transiting exoplanets over a wide wavelength range in the near-infrared. Methods: By using an inverse method approach, combined with stellar models and telluric transmission spectra, the method recovers the transiting exoplanet's atmospheric transmittance at high precision over a wide wavelength range. We describe our method and have tested it by simulating observations. Results: This method is capable of recovering transmission spectra of high enough accuracy to identify absorption features from molecules such as O2, CH4, CO2, and H2O. This accuracy is achievable for Jupiter-size exoplanets at S/N that can be reached for 8 m class telescopes using high-resolution spectrometers (R> 20 000) during a single transit, and for Earth-size planets and super-Earths transiting late K or M dwarf stars at S/N reachable during observations of less than 10 transits. We also analyse potential error sources to show the robustness of the method. Conclusions: Detection and characterization of atmospheres of both Jupiter-size planets and smaller rocky planets looks promising using this set-up.

  15. Exploration of in vivo Effect Assessment Factor Monitoring by Near-infrared Spectroscopy during LITT

    NASA Astrophysics Data System (ADS)

    Qian, Ai-ping; Hua, Guo-ran; Zhang, Hua; Qian, Zhi-yu

    2011-02-01

    By studying the variation trends of the absorption coefficient (μa) and the reduced scattering coefficient (μ's), which were monitored in vivo by functional near infrared spectroscopy (fNIRS) system in real time during laser induced interstitial thermotherapy (LITT), the optimized near infrared effect assessment factor would be explored. In vivo measurements of the absorption coefficient (ua) and the reduced scattering coefficient (u's) were performed with a functional near infrared spectroscopy system during LITT. Fresh porcine liver tissue samples in vitro and the subcutaneous implanted rat liver cancers were examined in different laser doses and define heating times. The absorption coefficient obtained by the fNIRS increased in the pork liver experiments, but decreased in the rat liver cancer experiments. The reduced scattering coefficient increased in the pork liver experiments and the rat liver cancer experiments, it increased quickly at beginning, and gradually reached the stable state. Therefore, the reduced scattering coefficient is more suitable for reflecting the progress of damage during different biological tissues' LITT than the absorption coefficient. This conclusion will effectively guide the study of suitable therapy effect assessment system during LITT in real time.

  16. Review of functional near-infrared spectroscopy in neurorehabilitation.

    PubMed

    Mihara, Masahito; Miyai, Ichiro

    2016-07-01

    We provide a brief overview of the research and clinical applications of near-infrared spectroscopy (NIRS) in the neurorehabilitation field. NIRS has several potential advantages and shortcomings as a neuroimaging tool and is suitable for research application in the rehabilitation field. As one of the main applications of NIRS, we discuss its application as a monitoring tool, including investigating the neural mechanism of functional recovery after brain damage and investigating the neural mechanisms for controlling bipedal locomotion and postural balance in humans. In addition to being a monitoring tool, advances in signal processing techniques allow us to use NIRS as a therapeutic tool in this field. With a brief summary of recent studies investigating the clinical application of NIRS using motor imagery task, we discuss the possible clinical usage of NIRS in brain-computer interface and neurofeedback. PMID:27429995

  17. Analysis of silage composition by near-infrared reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    Reeves, James B., III; Blosser, Timothy H.; Colenbrander, V. F.

    1991-02-01

    Two studies were performed to investigate the feasibility of using near infrared reflectance spectroscopy (NIRS) with undried silages. In the first study silages were analyzed for major components (e. g. dry matter crude protein and other forms of nitrogen fiber and in vitro digestible dry matter) and short chain fatty acids (SCFA). NIRS was found to operate satisfactorily except for some forms of nitrogen and SCFA. In study two various methods of grinding spectral regions and sample presentation were examined. Undried Wiley ground samples in a rectangular cell gave the best overall results for non-dry ice undried grinds with wavelengths between 1100 and 2498 nm. Silages scanned after drying however produced the best results. Intact samples did not perform as well as ground samples and wavelengths below 1100 nm were of little use. 2 .

  18. Near-infrared Spectroscopy in the Brewing Industry.

    PubMed

    Sileoni, Valeria; Marconi, Ombretta; Perretti, Giuseppe

    2015-01-01

    This article offers an exhaustive description of the use of Near-Infrared (NIR) Spectroscopy in the brewing industry. This technique is widely used for quality control testing of raw materials, intermediates, and finished products, as well as process monitoring during malting and brewing. In particular, most of the reviewed works focus on the assessment of barley properties, aimed at quickly selecting the best barley varieties in order to produce a high-quality malt leading to high-quality beer. Various works concerning the use of NIR in the evaluation of raw materials, such as barley, malt, hop, and yeast, are also summarized here. The implementation of NIR sensors for the control of malting and brewing processes is also highlighted, as well as the use of NIR for quality assessment of the final product. PMID:24915307

  19. Biochemical and physiological basis of medical near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Joebsis-vander Vliet, Frans F.; Joebsis, Paul

    1999-10-01

    Near infrared spectroscopy (NIRS) can monitor both the redox status of Cytochrome c oxidase located in the mitochondria within the cell and the oxygenation of the blood in the tissue being monitored. Since the enzyme catalyzes more than 90% of oxygen utilization, it is the sink for the oxygen while the hemoglobin in the capillaries is the oxygen source. In order to evaluate the oxidative metabolic status of a tissue the optical data obtained from both molecules are commonly interpreted in the basis of test tube experiments with purified preparations. We are concerned that the validity of this practice may not have been tested sufficiently and raise four basic questions that have not yet been answered. Citing some examples of in vitro versus in vivo differences we conclude that more effort should be expended on the in vivo testing of the range of the signals, their natural variability, and the physiological and pathological meaning of their deviations from norm.

  20. Discrimination and Content Analysis of Fritillaria Using Near Infrared Spectroscopy

    PubMed Central

    Meng, Yu; Wang, Shisheng; Cai, Rui; Jiang, Bohai; Zhao, Weijie

    2015-01-01

    Fritillaria is a traditional Chinese herbal medicine which can be used to moisten the lungs. The objective of this study is to develop simple, accurate, and solvent-free methods to discriminate and quantify Fritillaria herbs from seven different origins. Near infrared spectroscopy (NIRS) methods are established for the rapid discrimination of seven different Fritillaria samples and quantitative analysis of their total alkaloids. The scaling to first range method and the partial least square (PLS) method are used for the establishment of qualitative and quantitative analysis models. As a result of evaluation for the qualitative NIR model, the selectivity values between groups are always above 2, and the mistaken judgment rate of fifteen samples in prediction sets was zero. This means that the NIR model can be used to distinguish different species of Fritillaria herbs. The established quantitative NIR model can accurately predict the content of total alkaloids from Fritillaria samples. PMID:25789196

  1. Functional Near Infrared Spectroscopy: Watching the Brain in Flight

    NASA Technical Reports Server (NTRS)

    Harrivel, Angela; Hearn, Tristan A.

    2012-01-01

    Functional Near Infrared Spectroscopy (fNIRS) is an emerging neurological sensing technique applicable to optimizing human performance in transportation operations, such as commercial aviation. Cognitive state can be determined via pattern classification of functional activations measured with fNIRS. Operational application calls for further development of algorithms and filters for dynamic artifact removal. The concept of using the frequency domain phase shift signal to tune a Kalman filter is introduced to improve the quality of fNIRS signals in real-time. Hemoglobin concentration and phase shift traces were simulated for four different types of motion artifact to demonstrate the filter. Unwanted signal was reduced by at least 43%, and the contrast of the filtered oxygenated hemoglobin signal was increased by more than 100% overall. This filtering method is a good candidate for qualifying fNIRS signals in real time without auxiliary sensors.

  2. Functional Near Infrared Spectroscopy: Watching the Brain in Flight

    NASA Technical Reports Server (NTRS)

    Harrivel, Angela; Hearn, Tristan

    2012-01-01

    Functional Near Infrared Spectroscopy (fNIRS) is an emerging neurological sensing technique applicable to optimizing human performance in transportation operations, such as commercial aviation. Cognitive state can be determined via pattern classification of functional activations measured with fNIRS. Operational application calls for further development of algorithms and filters for dynamic artifact removal. The concept of using the frequency domain phase shift signal to tune a Kalman filter is introduced to improve the quality of fNIRS signals in realtime. Hemoglobin concentration and phase shift traces were simulated for four different types of motion artifact to demonstrate the filter. Unwanted signal was reduced by at least 43%, and the contrast of the filtered oxygenated hemoglobin signal was increased by more than 100% overall. This filtering method is a good candidate for qualifying fNIRS signals in real time without auxiliary sensors

  3. Recent advances in fetal near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    D'Antona, Donato; Aldrich, Clive J.; O'Brien, Patrick; Lawrence, Sally; Delpy, David T.; Wyatt, John S.

    1997-01-01

    Fetal brain injury resulting from hypoxia and ischemia during labor remains an important cause of death and long- term disability. However, little is known about fetal brain oxygenation and hemodynamics. There are currently no satisfactory clinical techniques for fetal monitoring and there remains a need for a new method to assess brain oxygenation. Fetal near infrared spectroscopy (NIRS) is a new technique that allows noninvasive observation of changes in the cerebral concentrations of oxyhemoglobin and deoxyhemoglobin to be made during labor. A specially designed optical probe is inserted through the dilated cervix and placed against the fetal head. It is then possible to compare changes in NIRS data with other observations of fetal conditions, such as fetal heart rate and acid-base status.

  4. Tissue blood flow and oxygen consumption measured with near-infrared frequency-domain spectroscopy

    NASA Astrophysics Data System (ADS)

    Paunescu, Lelia Adelina

    2001-12-01

    For decades, researchers have contributed with new ways of applying physics' principles to medicine. Moreover, researchers were involved in developing new, non-invasive instrumentation for medical applications. Recently, application of optical techniques in biology and medicine became an important field. Researchers found a non- invasive approach of using visible and near-infrared light as a probe for tissue investigation. Optical methods can contribute to medicine by offering the possibility of rapid, low-resolution, functional images and real-time devices. Near-infrared spectroscopy (NIRS) is a useful technique for the investigation of biological tissues because of the relatively low absorption of water and high absorption of oxy- and deoxy-hemoglobin in the near- infrared region of 750-900 nm. Due to these properties, the near-infrared light can penetrate biological tissues in the range of 0.5-2 cm, offering investigation possibility of deep tissues and differentiate among healthy and diseased tissues. This work represents the initial steps towards understanding and improving of the promising near- infrared frequency-domain technique. This instrument has a very important advantage: it can be used non-invasively to investigate many parts of the human body, including the brain. My research consists primarily of in vivo measurements of optical parameters such as absorption and reduced scattering coefficients and consequently, blood parameters such as oxy, deoxy, and total hemoglobin concentrations, tissue oxygen saturation, blood flow and oxygen consumption of skeletal muscle of healthy and diseased subjects. This research gives a solid background towards a ready- to-use instrument that can continuously, in real-time, measure blood parameters and especially blood oxygenation. This is a very important information in emergency medicine, for persons under intensive care, or undergoing surgery, organ transplant or other interventions.

  5. Near-Infrared Spectroscopy of 12 Outer Main Belt Asteroids

    NASA Astrophysics Data System (ADS)

    Takir, Driss; Emery, J. P.

    2010-10-01

    We have begun a project to quantify the degree of aqueous alteration in CM carbonaceous chondrites, obtain spectra of these chondrites, and measure spectra of possibly related outer Main Belt asteroids in order to explore the nature of aqueous alteration on these asteroids. In this first stage of the project, we will present the near-infrared (NIR) spectra of 12 outer Main Belt asteroids (2.59 < a < 3.96 AU). The asteroids include, 10 Hygiea, 76 Friea, 91 Aegina, 107 Camila, 104 Klymene, 121 Hemione, 153 Hilda, 308 Polyxo, 334 Chicago, 361 Bononia, 401 Ottilia, and 790 Pretoria. We collected the spectra of these asteroids between April 2009 and April 2010, using the long wavelength cross-dispersed (LXD) mode (1.9-4.1-µm) of the SpeX spectrograph/imager at the NASA Infrared Telescope Facility (IRTF). We also observed some of these asteroids with the prism mode (0.8-2.5-µm). For data reduction, we used Spextool, a set of Interactive Data Language routines provided by the IRTF. Except for 91 Aegina, all observed asteroids exhibit an absorption feature near 3-µm, which is attributed to hydrated minerals and/or H2O ice. The hydrated mineral features on these asteroids show two different band shapes, weak "rounded” H2O-like absorption band and deeper "checkmark” OH-like absorption band. The former band shape is much more common in our sample than the latter band shape.

  6. Utilization of functional near infrared spectroscopy for non-invasive evaluation

    NASA Astrophysics Data System (ADS)

    Halim, A. A. A.; Laili, M. H.; Aziz, N. A.; Laili, A. R.; Salikin, M. S.; Rusop, M.

    2016-07-01

    The goal of this brief review is to report the techniques of functional near infrared spectroscopy for non-invasive evaluation in human study. The development of functional near infrared spectroscopy (fNIRS) technologies has advanced quantification signal using multiple wavelength and detector to solve the propagation of light inside the tissues including the absorption, scattering coefficient and to define the light penetration into tissues multilayers. There are a lot of studies that demonstrate signal from fNIRS which can be used to evaluate the changes of oxygenation level and measure the limitation of muscle performance in human brain and muscle tissues. Comprehensive reviews of diffuse reflectance based on beer lambert law theory were presented in this paper. The principle and development of fNIRS instrumentation is reported in detail.

  7. Optimal hemodynamic response model for functional near-infrared spectroscopy

    PubMed Central

    Kamran, Muhammad A.; Jeong, Myung Yung; Mannan, Malik M. N.

    2015-01-01

    Functional near-infrared spectroscopy (fNIRS) is an emerging non-invasive brain imaging technique and measures brain activities by means of near-infrared light of 650–950 nm wavelengths. The cortical hemodynamic response (HR) differs in attributes at different brain regions and on repetition of trials, even if the experimental paradigm is kept exactly the same. Therefore, an HR model that can estimate such variations in the response is the objective of this research. The canonical hemodynamic response function (cHRF) is modeled by two Gamma functions with six unknown parameters (four of them to model the shape and other two to scale and baseline respectively). The HRF model is supposed to be a linear combination of HRF, baseline, and physiological noises (amplitudes and frequencies of physiological noises are supposed to be unknown). An objective function is developed as a square of the residuals with constraints on 12 free parameters. The formulated problem is solved by using an iterative optimization algorithm to estimate the unknown parameters in the model. Inter-subject variations in HRF and physiological noises have been estimated for better cortical functional maps. The accuracy of the algorithm has been verified using 10 real and 15 simulated data sets. Ten healthy subjects participated in the experiment and their HRF for finger-tapping tasks have been estimated and analyzed. The statistical significance of the estimated activity strength parameters has been verified by employing statistical analysis (i.e., t-value > tcritical and p-value < 0.05). PMID:26136668

  8. Near Infrared Spectroscopy and Imaging of Star Cluster Mercer 17

    NASA Astrophysics Data System (ADS)

    Moreau, Julie May; Clemens, D.; Jameson, K.; Pavel, M.; Pinnick, A.

    2010-01-01

    Mercer 17 is a recently discovered and as yet unstudied candidate star cluster located in the inner disk of the Milky Way (Mercer et al. 2005 ApJ 635, 560). Follow up studies are necessary to test the validity of proposed star clusters identified by imaging. The majority of well studied star clusters are outer galaxy clusters because of decreased extinction there. Using infrared enables probing into the inner galaxy to larger distances and to younger environments. Determining the basic properties of these newly discovered star cluster candidates, like Mercer 17, provides new insight into their formation. We obtained medium resolution (R=560-780) H- and K-band spectroscopy for eight of the brightest stars using the Mimir near-infrared instrument on the Perkins 1.83m telescope outside Flagstaff, Arizona. In addition to the spectroscopy observations, deep JHK band photometry was obtained for the cluster. Using these imaging and spectroscopic data, we present classified spectra and derived magnitudes of the stars in Mercer 17. Combining color magnitude diagrams and spectroscopy, we estimate basic cluster properties including age, distance, and total mass. Partially funded by an Undergraduate Research Opportunities Program (UROP) Award as a Clare Boothe Luce Summer Undergraduate Research Fellow and NSF grants AST 06-07500 and AST 09-07790

  9. Near Infrared Spectroscopy for Burning Plasma Diagnostic Applications

    SciTech Connect

    Soukhanovskii, V A

    2008-06-18

    Ultraviolet and visible (UV-VIS, 200-750 nm) atomic spectroscopy of neutral and ion fuel species (H, D, T, Li) and impurities (e.g. He, Be, C, W) is a key element of plasma control and diagnosis on ITER and future magnetically confined burning plasma experiments (BPX). Spectroscopic diagnostic implementation and performance issues that arise in the BPX harsh nuclear environment in the UV-VIS range, e.g., degradation of first mirror reflectivity under charge-exchange atom bombardment (erosion) and impurity deposition, permanent and dynamic loss of window and optical fiber transmission under intense neutron and {gamma}-ray fluxes, are either absent or not as severe in the near-infrared (NIR, 750-2000 nm) range. An initial survey of NIR diagnostic applications has been undertaken on the National Spherical Torus Experiment. It is demonstrated that NIR spectroscopy can address machine protection and plasma control diagnostic tasks, as well as plasma performance evaluation and physics studies. Emission intensity estimates demonstrate that NIR measurements are possible in the BPX plasma operating parameter range. Complications in the NIR range due to parasitic background emissions are expected to occur at very high plasma densities, low impurity densities, and at high plasma facing component temperatures.

  10. Near-Infrared Spectroscopy for the Evaluation of Anesthetic Depth

    PubMed Central

    Hernandez-Meza, Gabriela; Izzetoglu, Meltem; Osbakken, Mary; Green, Michael; Izzetoglu, Kurtulus

    2015-01-01

    The standard-of-care guidelines published by the American Society of Anesthesiologists (ASA) recommend monitoring of pulse oximetry, blood pressure, heart rate, and end tidal CO2 during the use of anesthesia and sedation. This information can help to identify adverse events that may occur during procedures. However, these parameters are not specific to the effects of anesthetics or sedatives, and therefore they offer little, to no, real time information regarding the effects of those agents and do not give the clinician the lead-time necessary to prevent patient “awareness.” Since no “gold-standard” method is available to continuously, reliably, and effectively monitor the effects of sedatives and anesthetics, such a method is greatly needed. Investigation of the use of functional near-infrared spectroscopy (fNIRS) as a method for anesthesia or sedation monitoring and for the assessment of the effects of various anesthetic drugs on cerebral oxygenation has started to be conducted. The objective of this paper is to provide a thorough review of the currently available published scientific studies regarding the use of fNIRS in the fields of anesthesia and sedation monitoring, comment on their findings, and discuss the future work required for the translation of this technology to the clinical setting. PMID:26495317

  11. Wearable near-infrared spectroscopy neuroimaging and its applications.

    PubMed

    Funane, Tsukasa

    2015-08-01

    Wearable near-infrared spectroscopy (NIRS) systems are expected to be applied in various fields such as health care (medical use), education (teaching), and biofeedback. An investigation on hyperscanning by using NIRS is discussed first, where multiple brains were simultaneously measured for investigating and evaluating important social interactions, such as communication. The relationship between interacting brain activities and performance in cooperation has been demonstrated. An investigation on mood-state measurements in a return-to-work program is next discussed. It has been reported that a specified index calculated using NIRS signals obtained during performance of a working memory task correlated with a mood score. Using this index, the mood states of volunteers who participated in a return-to-work program after psychiatric clinical treatment were monitored. It has been suggested that the relationship between brain activities and subjective assessment of depression mood will be useful for evaluating the recovery stage for return-to-work programs. These techniques open new applications of wearable NIRS systems in mental health care. PMID:26737177

  12. Textile integrated sensors and actuators for near-infrared spectroscopy.

    PubMed

    Zysset, Christoph; Nasseri, Nassim; Büthe, Lars; Münzenrieder, Niko; Kinkeldei, Thomas; Petti, Luisa; Kleiser, Stefan; Salvatore, Giovanni A; Wolf, Martin; Tröster, Gerhard

    2013-02-11

    Being the closest layer to our body, textiles provide an ideal platform for integrating sensors and actuators to monitor physiological signals. We used a woven textile to integrate photodiodes and light emitting diodes. LEDs and photodiodes enable near-infrared spectroscopy (NIRS) systems to monitor arterial oxygen saturation and oxygenated and deoxygenated hemoglobin in human tissue. Photodiodes and LEDs are mounted on flexible plastic strips with widths of 4 mm and 2 mm, respectively. The strips are woven during the textile fabrication process in weft direction and interconnected with copper wires with a diameter of 71 μm in warp direction. The sensor textile is applied to measure the pulse waves in the fingertip and the changes in oxygenated and deoxygenated hemoglobin during a venous occlusion at the calf. The system has a signal-to-noise ratio of more than 70 dB and a system drift of 0.37% ± 0.48%. The presented work demonstrates the feasibility of integrating photodiodes and LEDs into woven textiles, a step towards wearable health monitoring devices. PMID:23481780

  13. Rapid Characterization of Tanshinone Extract Powder by Near Infrared Spectroscopy

    PubMed Central

    Luo, Gan; Xu, Bing; Shi, Xinyuan; Li, Jianyu; Dai, Shengyun; Qiao, Yanjiang

    2015-01-01

    Chemical and physical quality attributes of herbal extract powders play an important role in the research and development of Chinese medicine preparations. The active pharmaceutical ingredients have a direct impact on the herbal extract's efficacy, while the physical properties of raw material affect the pharmaceutical manufacturing process and the final products' quality. In this study, tanshinone extract powders from Salvia miltiorrhiza which are widely used for the treatment of cardiovascular diseases in the clinic are taken as the research object. Both the chemical information and physical information of tanshinone extract powders are analyzed by near infrared (NIR) spectroscopy. The partial least squares (PLS) and least square support vector machine (LS-SVM) models are investigated to build the relationship between NIR spectra and reference values. PLS models performed well for the content of crytotanshinone, tanshinone IIA, the moisture, and average median particle size, while, for specific surface area and tapped density, the LS-SVM models performed better than the PLS models. Results demonstrated NIR to be a valid and fast process analytical technology tool to simultaneously determine multiple quality attributes of herbal extract powders and indicated that there existed some nonlinear relationship between NIR spectra and physical quality attributes. PMID:25866511

  14. Near infrared spectroscopy based brain-computer interface

    NASA Astrophysics Data System (ADS)

    Ranganatha, Sitaram; Hoshi, Yoko; Guan, Cuntai

    2005-04-01

    A brain-computer interface (BCI) provides users with an alternative output channel other than the normal output path of the brain. BCI is being given much attention recently as an alternate mode of communication and control for the disabled, such as patients suffering from Amyotrophic Lateral Sclerosis (ALS) or "locked-in". BCI may also find applications in military, education and entertainment. Most of the existing BCI systems which rely on the brain's electrical activity use scalp EEG signals. The scalp EEG is an inherently noisy and non-linear signal. The signal is detrimentally affected by various artifacts such as the EOG, EMG, ECG and so forth. EEG is cumbersome to use in practice, because of the need for applying conductive gel, and the need for the subject to be immobile. There is an urgent need for a more accessible interface that uses a more direct measure of cognitive function to control an output device. The optical response of Near Infrared Spectroscopy (NIRS) denoting brain activation can be used as an alternative to electrical signals, with the intention of developing a more practical and user-friendly BCI. In this paper, a new method of brain-computer interface (BCI) based on NIRS is proposed. Preliminary results of our experiments towards developing this system are reported.

  15. Near-infrared imaging spectroscopy for counterfeit drug detection

    NASA Astrophysics Data System (ADS)

    Arnold, Thomas; De Biasio, Martin; Leitner, Raimund

    2011-06-01

    Pharmaceutical counterfeiting is a significant issue in the healthcare community as well as for the pharmaceutical industry worldwide. The use of counterfeit medicines can result in treatment failure or even death. A rapid screening technique such as near infrared (NIR) spectroscopy could aid in the search for and identification of counterfeit drugs. This work presents a comparison of two laboratory NIR imaging systems and the chemometric analysis of the acquired spectroscopic image data. The first imaging system utilizes a NIR liquid crystal tuneable filter and is designed for the investigation of stationary objects. The second imaging system utilizes a NIR imaging spectrograph and is designed for the fast analysis of moving objects on a conveyor belt. Several drugs in form of tablets and capsules were analyzed. Spectral unmixing techniques were applied to the mixed reflectance spectra to identify constituent parts of the investigated drugs. The results show that NIR spectroscopic imaging can be used for contact-less detection and identification of a variety of counterfeit drugs.

  16. Fully Automated Lipid Pool Detection Using Near Infrared Spectroscopy

    PubMed Central

    Wojakowski, Wojciech

    2016-01-01

    Background. Detecting and identifying vulnerable plaque, which is prone to rupture, is still a challenge for cardiologist. Such lipid core-containing plaque is still not identifiable by everyday angiography, thus triggering the need to develop a new tool where NIRS-IVUS can visualize plaque characterization in terms of its chemical and morphologic characteristic. The new tool can lead to the development of new methods of interpreting the newly obtained data. In this study, the algorithm to fully automated lipid pool detection on NIRS images is proposed. Method. Designed algorithm is divided into four stages: preprocessing (image enhancement), segmentation of artifacts, detection of lipid areas, and calculation of Lipid Core Burden Index. Results. A total of 31 NIRS chemograms were analyzed by two methods. The metrics, total LCBI, maximal LCBI in 4 mm blocks, and maximal LCBI in 2 mm blocks, were calculated to compare presented algorithm with commercial available system. Both intraclass correlation (ICC) and Bland-Altman plots showed good agreement and correlation between used methods. Conclusions. Proposed algorithm is fully automated lipid pool detection on near infrared spectroscopy images. It is a tool developed for offline data analysis, which could be easily augmented for newer functions and projects. PMID:27610191

  17. Fully Automated Lipid Pool Detection Using Near Infrared Spectroscopy.

    PubMed

    Pociask, Elżbieta; Jaworek-Korjakowska, Joanna; Malinowski, Krzysztof Piotr; Roleder, Tomasz; Wojakowski, Wojciech

    2016-01-01

    Background. Detecting and identifying vulnerable plaque, which is prone to rupture, is still a challenge for cardiologist. Such lipid core-containing plaque is still not identifiable by everyday angiography, thus triggering the need to develop a new tool where NIRS-IVUS can visualize plaque characterization in terms of its chemical and morphologic characteristic. The new tool can lead to the development of new methods of interpreting the newly obtained data. In this study, the algorithm to fully automated lipid pool detection on NIRS images is proposed. Method. Designed algorithm is divided into four stages: preprocessing (image enhancement), segmentation of artifacts, detection of lipid areas, and calculation of Lipid Core Burden Index. Results. A total of 31 NIRS chemograms were analyzed by two methods. The metrics, total LCBI, maximal LCBI in 4 mm blocks, and maximal LCBI in 2 mm blocks, were calculated to compare presented algorithm with commercial available system. Both intraclass correlation (ICC) and Bland-Altman plots showed good agreement and correlation between used methods. Conclusions. Proposed algorithm is fully automated lipid pool detection on near infrared spectroscopy images. It is a tool developed for offline data analysis, which could be easily augmented for newer functions and projects. PMID:27610191

  18. Near-infrared spectroscopy of Type Ia supernovae

    NASA Astrophysics Data System (ADS)

    Hsiao, Eric; Phillips, Mark; Burns, Christopher R.; Contreras, Carlos; Gall, Christa; Hoeflich, Peter; Kirshner, Robert P.; Marion, Howie H.; Morrell, Nidia; Sand, David J.; Stritzinger, Maximillian; Carnegie Supernova Project

    2016-01-01

    Improving the cosmological experiments with Type Ia supernovae (SNe Ia) is now not simply a question of observing more supernovae, since any survey, no matter how large, will ultimately be limited by the systematic errors. It has been clearly demonstrated in a number of studies that SNe Ia are better distance indicators in the near-infrared compared to the optical. As exciting as these new results are, SNe Ia in the NIR are expected to be even better than these studies indicate. A key ingredient for improving SN Ia in the NIR as distance indicators is to obtain NIR spectroscopy to determine precise k-corrections, which account for the effect of cosmological expansion upon the measured magnitudes. Better knowledge of the NIR spectroscopic behaviors, akin to that in the optical, is necessary to reach the distance precision required to identify viable models for dark energy. Carnegie Supernova Project II has built a definitive data set, much improved from previous samples, both in size and quality. With this previously unavailable window, we are also beginning to gain new insight on the physics of these events.

  19. Detecting concealed information using functional near-infrared spectroscopy.

    PubMed

    Sai, Liyang; Zhou, Xiaomei; Ding, Xiao Pan; Fu, Genyue; Sang, Biao

    2014-09-01

    The present study focused on the potential application of fNIRS in the detection of concealed information. Participants either committed a mock crime or not and then were presented with a randomized series of probes (crime-related information) and irrelevants (crime-irrelevant information) in a standard concealed information test (CIT). Participants in the guilty group were instructed to conceal crime-related information they obtained from the mock crime, thus making deceptive response to the probes. Meanwhile, their brain activity to probes and irrelevants was recorded by functional near-infrared spectroscopy (fNIRS). At the group level, we found that probe items were associated with longer reaction times and greater activity in bilateral dorsolateral prefrontal cortex and supplementary motor cortex than irrelevant items in the guilty group, but not in the innocent group. These findings provided evidence on neural correlates of recognition during a CIT. Finally, on the basis of the activity in bilateral dorsolateral prefrontal cortex and supplementary motor cortex, the correct classification of guilty versus innocent participants was approximately 75 % and the combination of fNIRS and reaction time measures yielded a better classification rate of 83.3 %. These findings illustrate the feasibility and promise of using fNIRS to detect concealed information. PMID:24514911

  20. Prediction of chicken quality attributes by near infrared spectroscopy.

    PubMed

    Barbin, Douglas Fernandes; Kaminishikawahara, Cintia Midori; Soares, Adriana Lourenco; Mizubuti, Ivone Yurika; Grespan, Moises; Shimokomaki, Massami; Hirooka, Elisa Yoko

    2015-02-01

    In the present study, near-infrared (NIR) reflectance was tested as a potential technique to predict quality attributes of chicken breast (Pectoralis major). Spectra in the wavelengths between 400 and 2500nm were analysed using principal component analysis (PCA) and quality attributes were predicted using partial least-squares regression (PLSR). PCA performed on NIR dataset revealed the influence of muscle reflectance (L(∗)) influencing the spectra. PCA was not successful to completely discriminate between pale, soft and exudative (PSE) and pale-only muscles. High-quality PLSR were obtained for L(∗) and pH models predicted individually (R(2)CV of 0.91 and 0.81, and SECV of 1.99 and 0.07, respectively). Water-holding capacity was the most challenging attribute to determine (R(2)CV of 0.70 and SECV of 2.40%). Sample mincing and different spectra pre-treatments were not necessary to maximise the predictive performance of models. Results suggest that NIR spectroscopy can become useful tool for quality assessment of chicken meat. PMID:25172747

  1. Phase-amplitude crosstalk in intensity modulated near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Alford, K.; Wickramasinghe, Y.

    2000-05-01

    Near infrared spectroscopy (NIRS) instruments that rely on phase sensitive detection suffer from what is called "phase-amplitude crosstalk," i.e., the phase measured is dependent on the average light intensity entering the detector. Changes in detector rise time with input light intensity is the accepted explanation of this phenomenon. It is concluded here that an additional simple mechanism can cause phase-amplitude errors, particularly if the ratio of the ac component of the detected signal to the dc component is low. It is shown that the form of the phase distortion encountered during the development of a new phase sensitive NIR instrument can be modeled by assuming the presence of a synchronous interfering signal, due to rf coupling, at the detector output. This modeling allows a required margin between the detected signal of interest, i.e., the signal from the tissue and the interfering signal to be set in order to achieve a measured phase accuracy necessary to derive sufficiently accurate clinical parameters.

  2. Application of functional near-infrared spectroscopy in psychiatry.

    PubMed

    Ehlis, Ann-Christine; Schneider, Sabrina; Dresler, Thomas; Fallgatter, Andreas J

    2014-01-15

    Two decades ago, the introduction of functional near-infrared spectroscopy (fNIRS) into the field of neuroscience created new opportunities for investigating neural processes within the human cerebral cortex. Since then, fNIRS has been increasingly used to conduct functional activation studies in different neuropsychiatric disorders, most prominently schizophrenic illnesses, affective disorders and developmental syndromes, such as attention-deficit/hyperactivity disorder as well as normal and pathological aging. This review article provides a comprehensive overview of state of the art fNIRS research in psychiatry covering a wide range of applications, including studies on the phenomenological characterization of psychiatric disorders, descriptions of life-time developmental aspects, treatment effects, and genetic influences on neuroimaging data. Finally, methodological shortcomings as well as current research perspectives and promising future applications of fNIRS in psychiatry are discussed. We conclude that fNIRS is a valid addition to the range of neuroscientific methods available to assess neural mechanisms underlying neuropsychiatric disorders. Future research should particularly focus on expanding the presently used activation paradigms and cortical regions of interest, while additionally fostering technical and methodological advances particularly concerning the identification and removal of extracranial influences on fNIRS data as well as systematic artifact correction. Eventually, fNIRS might be a useful tool in practical psychiatric settings involving both diagnostics and the complementary treatment of psychological disorders using, for example, neurofeedback applications. PMID:23578578

  3. Near-infrared spectroscopy for rapid classification of fruit spirits.

    PubMed

    Jakubíková, M; Sádecká, J; Kleinová, A; Májek, P

    2016-06-01

    Multivariate analysis combined with near-infrared (NIR) spectral analysis was evaluated to classify fruit spirits. A total of 67 fruit spirits (12 apple, 18 apricot, 19 pear and 18 plum spirits) were analyzed. NIR spectra were collected in the wavenumber range of 4000-10,000 cm(-1). Linear discriminant analysis based on principal component analysis (PCA-LDA) and general discriminant analysis (GDA) based directly on NIR spectral data were used to classify the samples. The prediction performance of models in different wavenumber ranges was also investigated. The best PCA-LDA and GDA models gave a 100 % classification of spirits of the four fruit kinds in the wavenumber range from 5500 to 6050 cm(-1) corresponding to either the C-H stretch of the first overtones of CH3 and CH2 groups, or to compounds containing O-H aromatic groups. The results demonstrated that NIR spectroscopy could be used as a rapid method for classification of fruit spirits. PMID:27478236

  4. Near Infrared Spectroscopy of B-type Asteroids

    NASA Astrophysics Data System (ADS)

    Yang, Bin; Jewitt, D.

    2009-09-01

    Most small bodies in the Solar system possess optical colors that are either redder than, or comparable to, the Solar colors in the wavelength region from 0.4 to 0.9 µm. However, a small fraction, about 1 out of every 23 asteroids, is found to be bluer than the Sun. These rare, blue asteroids, of which 2 Pallas is the largest and most famous example, are classified as B-types in the Bus spectral taxonomy. The paucity of B-types already makes these objects interesting. Moreover, several meteor shower-associated asteroids (e.g. 3200 Phaethon, 2005 UD) are found to be blue in the optical. Furthermore, the available optical spectra of the main belt comets 133P and 176P are similar to those of the B-type asteroids. However, B-type asteroids remain largely unexamined as a group and our knowledge of their properties is correspondingly limited. For this reason, we undertook a focused, spectroscopic study of 20 B-type asteroids using the 3-meter IRTF telescope atop Mauna Kea, Hawaii. The spectra show that optically similar B-type asteroids are spectrally diverse in the near infrared. We find that the negative optical spectral slope is due to the presence of a broad absorption band centered near 1.0 µm. Amongst the meteorites, the best spectral analogs are found in the unusual CI and CM carbonaceous chondrites. The 1.0 µm absorption feature in several objects is very well matched by the reflection spectrum of magnetite. We will present our observations of the 20 B-type asteroids and discuss the possible aqueous alteration history of these objects.

  5. Nondestructive Assessment of Engineered Cartilage Composition by Near Infrared Spectroscopy.

    PubMed

    McGoverin, Cushla M; Hanifi, Arash; Palukuru, Uday P; Yousefi, Farzad; Glenn, Padraig B M; Shockley, Michael; Spencer, Richard G; Pleshko, Nancy

    2016-03-01

    Tissue engineering presents a strategy to overcome the limitations of current tissue healing methods. Scaffolds, cells, external growth factors and mechanical input are combined in an effort to obtain constructs with properties that mimic native tissues. However, engineered constructs developed using similar culture environments can have very different matrix composition and biomechanical properties. Accordingly, a nondestructive technique to assess constructs during development such that appropriate compositional endpoints can be defined is desirable. Near infrared spectroscopy (NIRS) analysis is a modality being investigated to address the challenges associated with current evaluation techniques, which includes nondestructive compositional assessment. In the present study, cartilage tissue constructs were grown using chondrocytes seeded onto polyglycolic acid (PGA) scaffolds in similar environments in three separate tissue culture experiments and monitored using NIRS. Multivariate partial least squares (PLS) analysis models of NIR spectra were calculated and used to predict tissue composition, with biochemical assay information used as the reference data. Results showed that for combined data from all tissue culture experiments, PLS models were able to assess composition with significant correlations to reference values, including engineered cartilage water (at 5200 cm(-1), R = 0.68, p = 0.03), proteoglycan (at 4310 cm(-1), R = 0.82, p = 0.007), and collagen (at 4610 cm(-1), R = 0.84, p = 0.005). In addition, degradation of PGA was monitored using specific NIRS frequencies. These results demonstrate that NIR spectroscopy combined with multivariate analysis provides a nondestructive modality to assess engineered cartilage, which could provide information to determine the optimal time for tissue harvest for clinical applications. PMID:26817457

  6. Detecting and Segregating Black Tip-Damaged Wheat Kernels Using Visible and Near Infrared Spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Detection of individual wheat kernels with black tip symptom (BTS) and black tip damage (BTD) was demonstrated using near infrared reflectance spectroscopy (NIRS) and silicon light-emitting-diode (LED) based instruments. The two instruments tested, a single kernel near-infrared spectroscopy instrume...

  7. Reliability of Near-Infrared Spectroscopy for Determining Muscle Oxygen Saturation during Exercise

    ERIC Educational Resources Information Center

    Austin, Krista G.; Daigle, Karen A.; Patterson, Patricia; Cowman, Jason; Chelland, Sara; Haymes, Emily M.

    2005-01-01

    Near-infrared spectroscopy is currently used to assess changes in the oxygen saturation of the muscle during exercise. The primary purpose of this study was to assess the reliability of near-infrared spectroscopy in determining muscle oxygen saturation (StO[subscript 2]) in the vastus lateralis during cycling and the gastrocnemius during running…

  8. Implanted near-infrared spectroscopy for cardiac monitoring

    NASA Astrophysics Data System (ADS)

    Bhunia, Sourav K.; Cinbis, Can

    2011-02-01

    Implanted Cardioverter Defibrillator (ICD) provides one of the most effective therapies for the prevention of sudden cardiac death, but also delivers some high voltage shocks inappropriately, causing morbidity and mortality. Implanted near-infrared spectroscopy (NIRS) may augment ICD arrhythmia detection by monitoring skeletal muscle perfusion. A two-wavelength, single-distance, continuous-wave implanted NIRS has been evaluated in-vivo. A weighted difference of the changes in attenuation at two wavelengths, across the isobestic point of the hemoglobin spectra, was taken to be the microvascular oxygenation trend indicator (O2 Index). Although the exact weight depends on the local vascular distribution and their oxygen levels, the hypothesis that a constant weight may be adequate for hemodynamic trending during short arrhythmic episodes, was tested. The sensor was implanted subcutaneously both on fresh tissue and inside scar tissue that formed around a pre-existing implant, in 3 animals each. Attenuations were recorded at 660 and 890 nm during normal sinus rhythm (NSR) and induced ventricular fibrillation (VF). The slope of the O2 Index over 10 seconds was computed for 7 NSR and 8 VF episodes in fresh and 13 NSR and 15 VF episodes in scar tissue pockets. The mean O2 Index slope was significantly different (p<0.0001) between NSR and VF rhythms for both the fresh and scar tissue pockets. Therefore implanted NIRS may be useful for preventing inappropriate detection of VF during electromagnetic interference, double counting of ECG T-wave as an R-wave, ICD lead failure, electrocardiographic aberrancy etc.

  9. Astronomical Spectroscopy: Calibration Sources for the Near Infrared

    NASA Astrophysics Data System (ADS)

    Kerber, Florian; Aldenius, Maria; Nave, Gillian; Sansonetti, Craig J.; Ralchenko, Yuri

    2009-05-01

    The European Southern Observatory (ESO) operates a multitude of telescopes and instruments at its La Silla Paranal Observatory in Chile. The most powerful ones are the four 8-m telescopes of the Very Large Telescope (VLT). ESO is currently studying an Extremely Large Telescope (ELT) with a diameter of the primary mirror of 42 m. This telescope will make use of various techniques of adaptive optics (AO) to counter the perturbing effect of Earth's atmosphere. Due to the wavelength dependent performance of AO the European ELT (E-ELT) will be most powerful in the near-infrared (IR) domain. A collaboration of ESO and the US Institute for Standards and Technology (NIST) has successfully established wavelength standards in the emission spectrum of Th-Ar hollow cathode lamps for high resolution spectroscopy. This has been a major advancement for near-IR astronomy, which has traditionally relied on atmospheric features for wavelength calibration. ESO and NIST report on joint efforts to identify and establish the best sources for wavelength calibration for the 2nd generation of VLT instrument and for the E-ELT. To this end we are studying the near-IR spectra of various elements. With the focus of astronomy moving toward IR wavelengths the astronomical community will have a need for a large amount of atomic and molecular data in order to perform the scientific analysis of their data. It will be essential that the long-standing and fruitful collaboration between astrophysics and the atomic and molecular physics community continues in the future.

  10. Evaluation of Phalaenopsis flowering quality using near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Chen, Suming; Chuang, Yung-Kun; Tsai, Chao-Yin; Chang, Yao-Chien A.; Yang, I.-Chang; Chang, Yung-Huei; Tai, Chu-Chun; Hou, Jiunn-Yan

    2013-05-01

    Carbohydrate contents have been demonstrated as indicators for flowering quality of Phalaenopsis plants. In this study, near infrared reflectance (NIR) spectroscopy was employed for quantitative analysis of carbohydrate contents like fructose, glucose, sucrose, and starch in Phalaenopsis. The modified partial least squares regression (MPLSR) method was adopted for spectra analyses of 176 grown plant samples (88 shoots and 88 roots), over the full wavelength range (FWR, 400 to 2498 nm). For fructose concentrations, the smoothing 1st derivative model can produce the best effect (Rc = 0.961, SEC = 0.210% DW, SEV = 0.324% DW) in the wavelength ranges of 1400-1600, 1800-2000, and 2200-2300 nm. For glucose concentrations, the smoothing 1st derivative model can produce the best effect (Rc = 0.975, SEC = 0.196% DW, SEV = 0.264% DW) in the wavelength range of 1400-1600, 1800-2000, and 2100-2400 nm. For sucrose concentrations, the smoothing 1st derivative model can produce the best effect (Rc = 0.961, SEC = 0.237% DW, SEV = 0.322% DW) in the wavelength range of 1300-1400, 1500-1800, 2000-2100, and 2200-2300 nm. For starch concentrations, the smoothing 1st derivative model can produce the best effect (Rc = 0.873, SEC = 0.697% DW, SEV = 0.774% DW) in the wavelength ranges of 500-700, 1200-1300, 1700-1800, and 2200-2300 nm. This study successfully developed the calibration models for inspecting concentrations of carbohydrates to predict the flowering quality in different cultivation environments of Phalaenopsis. The specific wavelengths can be used to predict the quality of Phalaenopsis flowers and thus to adjust cultivation managements.

  11. Fetal oxygenation measurement using wireless near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Macnab, Andrew; Shadgan, Babak; Janssen, Patricia; Rurak, Dan

    2012-03-01

    Background: Fetal well-being is determined in large part by how well the placenta is able to supply oxygen and nutrients, but current technology is unable to directly measure how well a placenta functions. Near-infrared spectroscopy (NIRS) utilizes optical methods to measure tissue oxygenation. This pilot project evaluated the feasibility of NIRS for fetal monitoring through the maternal abdominal wall using a sheep model. Methods: A miniature wireless 2-wavelength NIRS device was placed on the abdominal skin over the placenta of a pregnant ewe whose fetus had been chronically catheterized to allow arterial sampling for measurement of arterial oxygen saturation. The NIRS device has 3-paired light emitting diodes and a single photodiode detector; allowing measurement of an index of tissue oxygen saturation (TSI%). Fetal limb TSI% values were compared before and during fetal breathing movements. Correlation was made during these events between arterial values and placental TSI% monitored continuously in real time. Results: Serial measurements were obtained in a single experiment. The correlation between transcutaneous NIRS derived TSI% and direct arterial oxygen saturation was very high (R2=0.86). Measures of fetal limb TSI% were declined after episodes of fetal breathing (P<0.005). Conclusions: This correlation suggests that NIRS is sensitive enough to detect changes in fetal tissue oxygenation noninvasively through the maternal abdominal wall in real-time in a sheep model. NIRS data confirmed that fetal breathing movements decrease arterial oxygen saturation in fetal lambs. If validated by further study this optical methodology could be applied as means of monitoring fetal wellbeing in humans.

  12. MOS spectroscopy with the JWST Near-Infrared Spectrometer

    NASA Astrophysics Data System (ADS)

    Karakla, Diane M.; Beck, Tracy; Gilbert, Karoline; Pontoppidan, Klaus Martin; Curtis, Gary; Shyrokov, Alexander

    2015-08-01

    The James Webb Space Telescope's Near-Infrared Spectrograph (NIRSpec) will feature astronomy’s first space-based, multi-object spectroscopic (MOS) capability enabled by the instrument’s micro-shutter array (MSA). The MSA is a four-quadrant fixed grid of nearly 250,000 tiny shutters that can be configured into slits on multiple astronomical targets in a field. In MOS mode, NIRSpec can obtain spectra of more than 100 targets simultaneously in one of three spectral bands (1.0 - 1.8 μm, 1.7 - 3.0 μm, and 2.9 - 5.0 μm) at medium (R~1000) or high resolution (R~2700) with the gratings, or at lower resolution (R~100, 0.6 - 5.0 μm) with the PRISM. The NIRSpec team and software developers at the Space Telescope Science Institute (STScI) have developed an MSA Planning Tool (MPT) to facilitate the complex observation planning process for a variety of observing strategies. The purpose of the tool is to find optimal pointings on the sky where many sources (or many high-valued sources) can be observed at a given pointing, or through a set of telescope dithers, and to design the associated MSA configurations at each position. The MPT is available to the astronomical community as part of the Astronomer’s Proposal Tool (APT), an integrated software package developed by STScI for the preparation of observing proposals. We will summarize the operational concept for MOS spectroscopy with the instrument, describe the MSA Planning Tool and its algorithms, and highlight recent developments that extend the tool’s applicability to diverse science cases.

  13. Near-infrared Spectroscopy of EX Lupi in Outburst

    NASA Astrophysics Data System (ADS)

    Kóspál, Á.; Ábrahám, P.; Goto, M.; Regály, Zs.; Dullemond, C. P.; Henning, Th.; Juhász, A.; Sicilia-Aguilar, A.; van den Ancker, M.

    2011-07-01

    EX Lup is the prototype of the EXor class of young eruptive stars: objects showing repetitive brightenings due to increased accretion from the circumstellar disk to the star. In this paper, we report on medium-resolution near-infrared spectroscopy of EX Lup taken during its extreme outburst in 2008, as well as numerical modeling with the aim of determining the physical conditions around the star. We detect emission lines from atomic hydrogen, helium, and metals, as well as first overtone bandhead emission from carbon monoxide. Our results indicate that the emission lines are originating from gas located in a dust-free region within ≈0.2 AU of the star. The profile of the CO bandhead indicates that the CO gas has a temperature of 2500 K and is located in the inner edge of the disk or in the outer parts of funnel flows. The atomic metals are probably colocated with the CO. Some metallic lines are fluorescently excited, suggesting direct exposure to ultraviolet photons. The Brackett series indicates emission from hot (10,000 K) and optically thin gas. The hydrogen lines display a strong spectro-astrometric signal, suggesting that the hydrogen emission is probably not coming from an equatorial boundary layer; a funnel flow or disk wind origin is more likely. This picture is broadly consistent with the standard magnetospheric accretion model usually assumed for normally accreting T Tauri stars. Our results also set constraints on the eruption mechanism, supporting a model where material piles up around the corotation radius and episodically falls onto the star.

  14. Effect of mechanical optical clearing on near-infrared spectroscopy.

    PubMed

    Idelson, Christopher R; Vogt, William C; King-Casas, Brooks; LaConte, Stephen M; Rylander, Christopher G

    2015-08-01

    Near-infrared Spectroscopy (NIRS) is a broadly utilized technology with many emerging applications including clinical diagnostics, sports medicine, and functional neuroimaging, to name a few. For functional brain imaging NIR light is delivered at multiple wavelengths through the scalp and skull to the brain to enable spatial oximetry measurements. Dynamic changes in brain oxygenation are highly correlated with neural stimulation, activation, and function. Unfortunately, NIRS is currently limited by its low spatial resolution, shallow penetration depth, and, perhaps most importantly, signal corruption due to light interactions with superficial non-target tissues such as scalp and skull. In response to these issues, we have combined the non-invasive and rapidly reversible method of mechanical tissue optical clearing (MOC) with a commercially available NIRS system. MOC utilizes a compressive loading force on tissue, causing the lateral displacement of blood and water, while simultaneously thinning the tissue. A MOC-NIRS Breath Hold Test displayed a ∼3.5-fold decrease in the time-averaged standard deviation between channels, consequentially promoting greater channel agreement. A Skin Pinch Test was implemented to negate brain and muscle activity from affecting the recorded signal. These results displayed a 2.5-3.0 fold increase in raw signal amplitude. Existing NIRS instrumentation has been further integrated within a custom helmet device to provide a uniform force distribution across the NIRS sensor array. These results showed a gradual decrease in time-averaged standard deviation among channels with an increase in applied pressure. Through these experiments, and the development of the MOC-NIRS helmet device, MOC appears to provide enhancement of NIRS technology beyond its current limitations. PMID:26041069

  15. Near infrared spectroscopy monitoring in the pediatric cardiac catheterization laboratory.

    PubMed

    Tanidir, Ibrahim Cansaran; Ozturk, Erkut; Ozyilmaz, Isa; Saygi, Murat; Kiplapinar, Neslihan; Haydin, Sertac; Guzeltas, Alper; Odemis, Ender

    2014-10-01

    Near-infrared spectroscopy (NIRS) is a noninvasive method used to evaluate tissue oxygenation. We evaluated the relationship between cerebral and renal NIRS parameters during transcatheter intervention and adverse events in the catheterization room. Between January 1 and May 31, 2012, 123 of 163 pediatric patients undergoing cardiac catheterization were followed by NIRS. All were monitored by electrocardiography, noninvasive blood pressure measurement, pulse oxymetry, initial and final blood lactate level measurement. The number of interventional procedures was 73 (59%). During the procedures, 39 patients experienced a total of 41 adverse events: 18 (19.5%) had desaturation, 10 (8.1%) arrhythmia, three (2.4%) had respiratory difficulty, six (4.8%) had a situation calling for cardiopulmonary resuscitation, three (2.4%) had anemia necessitating transfusion, and one (0.8%) had a cyanotic spell. Cranial NIRS values worsened in 12 (9.8%) and renal measurements worsened in 13 (12.5%) patients. The sensitivity and specificity of a 9% impairment of cranial values were 90 and 61%, respectively, while the corresponding calculations for a 21% fall in renal measurements were 54% sensitivity and 90% specificity. When arrhythmia developed, NIRS values fell simultaneously, while the development of a desaturation problem was heralded by NIRS falling 10-15 s earlier than changes in pulse oxymetry; on improving saturation, NIRS returned to earlier values 10-15 s before pulse oxymetry readings. NIRS monitoring may provide an early warning with regard to complications likely to develop during a procedure. A fall of 9% in cranial NIRS values, or of 21% in renal measurements, should raise clinician awareness. PMID:24404951

  16. [Determination of adulteration in honey using near-infrared spectroscopy].

    PubMed

    Chen, Lan-Zhen; Zhao, Jing; Ye, Zhi-Hua; Zhong, Yan-Ping

    2008-11-01

    The objective of the present research is to study the potential of using Fourier transform near-infrared spectroscopy (FT-NIR) in conjunction with discriminant partial least squares (DPLS) chemometric techniques for the discrimination of honey authenticity. First, seventy one commercial honey samples from Chinese market were analyzed to detect the levels of honey adulteration by stable carbon isotope ratio and the chemical result showed that the samples include unadulterated (n = 27) and adulterated (n = 44) products. The samples were scanned in the spectral region between 4 000 and 11 000 cm(-1) by FT-NIR spectrometer with an optic fiber of 2 mm path-length and an InGaAs detector and then divided randomly five times into two sets, namely calibration sets and validation sets, respectively. Five kinds of mathematic models of honey samples were established for classification of honeys as authentic or adulterated by using DPLS. Different spectra pretreatment methods, spectral range and different principal component factors were selected to optimize the calibration models. The calibration models were successfully validated with exterior cross-validation methods. Through comparison analysis of the results, the overall corrected identification rate of authentic and adulterated honey samples in five calibration models were 91.49%, 94.68%, 92.98%, 93.86% and 94.87%, respectively. The correct classification rate of the validation samples was 93.75%, 89.58%, 89.29%, 92.31% and 86.96% from model one to model five, respectively and 100% of adulterated honey samples were correctly identified and classified in validation models 2, 3 and 4. The results demonstrated that FT-NIR together with DPLS could be used as a rapid and cost-efficient screening tool for discrimination of commercial honey adulteration, and the analytical technique would be significant to Chinese honey quality supervision. PMID:19271491

  17. [Noninvasive detection of the concentrations of pigments in pork tissue using near infrared spectroscopy].

    PubMed

    Teng, Yi-chao; Li, Yue; Huang, Lan; Ding, Hai-shu

    2010-01-01

    Based on the absorption spectra of hemoglobin and myoglobin in the near infrared band, the concentrations of these pigments in the biological tissues can be obtained using near infrared spectroscopy (NIRS) by detecting the intensity attenuation of the emitted light compared with the incident light. Based on the steady-state spatially resolved NIRS, the prototype for detecting the concentrations of tissue hemoglobin and myoglobin was independently developed by our group. The probe consisted of an LED light source which could emit three different wavelengths in the near infrared band, and two detectors which were placed on the same line with and at the distances of 30/40 mm to the LED. The pigment concentrations of two pieces of pork, one from the erector spinae and the other from the rectus femoris, were detected using this prototype. The total concentrations of hemoglobin and myoglobin (c(total)) were (6.42 + 1.51) micromol x L(-1) in the erector spinae, and (15.48 +/- 4.54) micromol x L(-1) in the rectus femoris, respectively. The myoglobin was dominant in both of the results. These were consistent with the recent empirical reports. In summary, the NIRS method and prototype are authentic in detecting the pigment concentrations of pork tissue non-invasively, real-time, directly and conveniently. PMID:20302083

  18. Noninvasive measurement of postocclusive parameters in human forearm blood by near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Rao, K. Prahlad; Radhakrishnan, S.; Reddy, M. Ramasubba

    2005-04-01

    Near infrared (NIR) light in the wavelength range from 700 to 900 nm can pass through skin, bone and other tissues relatively easily. As a result, NIR techniques allow a noninvasive assessment of hemoglobin saturation for a wide range of applications, such as in the study of muscle metabolism, the diagnosis of vascular disorders, brain imaging, and breast cancer detection. Near infrared Spectroscopy (NIRS) is an effective tool to measure the hemoglobin concentration in the tissues, which can discriminate optically the oxy- and deoxy- hemoglobin species because of their different near-infrared absorption spectra. We have developed an NIRS probe consisting of a laser diode of 830 nm wavelength and a PIN photodiode in reflectance mode. We have selected a set of healthy volunteers (mean age 30, range 26-40 years) for the study. The probe is placed on forearm of each subject and the backscattered light intensity is measured by occluding the blood flow at 210, 110 and 85 mmHg pressures. Recovery time, peak time and time after 50% release of the cuff pressure are determined from the optical densities during the post occlusive state of forearm. These parameters are useful for determining the transient increase in blood flow after the release of blood occlusion. Clinically, the functional aspects of blood flow in the limbs could be evaluated noninvasively by NIRS.

  19. Near-infrared spectroscopy of proto-planetary nebulae

    NASA Technical Reports Server (NTRS)

    Hrivnak, Bruce J.; Kwok, Sun; Geballe, T. R.

    1994-01-01

    Sixteen proto-planetary nebulae were observed with low-resolution infrared spectroscopy in the H and K bands, and four were observed in the L band. In the H band, most of the objects show hydrogen Brackett lines (from n = 10 goes to 4 to n = 20 goes to 4) in absorption. In the K band, absorption bands (delta (nu) = 2) of CO were observed to as high as nu = 6 goes to 4, and in three cases the CO bands are in emission. The CO spectrum of 22272 + 5435 was found to change from emission to absorption over a 3 month interval. The CO emission most likely arises from collisional excitation resulting from recent episodes of mass loss. One new object which possibly shows weak 3.3 micron emission was found.

  20. Simple route to (NH4)(x)WO3 nanorods for near infrared absorption.

    PubMed

    Guo, Chongshen; Yin, Shu; Dong, Qiang; Sato, Tsugio

    2012-06-01

    Described here is how to synthesize one-dimensional ammonium tungsten bronze ((NH(4))(x)WO(3)) by a facile solvothermal approach in which ethylene glycol and acetic acid were employed as solvents and ammonium paratungstate was used as a starting material, as well as how to develop the near infrared absorption properties of (NH(4))(x)WO(3) nanorods for application as a solar light control filter. The as-obtained product was characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetry (TG), atomic force microscope (AFM) and UV-Vis-NIR spectra. The SEM and TEM images clearly revealed that the obtained sample possessed rod/fiber-like morphologies with diameters around 120 nm. As determined by UV-Vis-NIR optical measurement, the thin film consisted of (NH(4))(x)WO(3) nanoparticles, which can selectively transmit most visible lights, but strongly absorb the near-infrared (NIR) lights and ultraviolet rays. These interesting optical properties make the (NH(4))(x)WO(3) nanorods suitable for the solar control windows. PMID:22543744

  1. Determination of plant silicon content with near infrared reflectance spectroscopy

    PubMed Central

    Smis, Adriaan; Ancin Murguzur, Francisco Javier; Struyf, Eric; Soininen, Eeva M.; Herranz Jusdado, Juan G.; Meire, Patrick; Bråthen, Kari Anne

    2014-01-01

    Silicon (Si) is one of the most common elements in the earth bedrock, and its continental cycle is strongly biologically controlled. Yet, research on the biogeochemical cycle of Si in ecosystems is hampered by the time and cost associated with the currently used chemical analysis methods. Here, we assessed the suitability of Near Infrared Reflectance Spectroscopy (NIRS) for measuring Si content in plant tissues. NIR spectra depend on the characteristics of the present bonds between H and N, C and O, which can be calibrated against concentrations of various compounds. Because Si in plants always occurs as hydrated condensates of orthosilicic acid (Si(OH)4), linked to organic biomolecules, we hypothesized that NIRS is suitable for measuring Si content in plants across a range of plant species. We based our testing on 442 samples of 29 plant species belonging to a range of growth forms. We calibrated the NIRS method against a well-established plant Si analysis method by using partial least-squares regression. Si concentrations ranged from detection limit (0.24 ppmSi) to 7.8% Si on dry weight and were well predicted by NIRS. The model fit with validation data was good across all plant species (n = 141, R2 = 0.90, RMSEP = 0.24), but improved when only graminoids were modeled (n = 66, R2 = 0.95, RMSEP = 0.10). A species specific model for the grass Deschampsia cespitosa showed even slightly better results than the model for all graminoids (n = 16, R2 = 0.93, RMSEP = 0.015). We show for the first time that NIRS is applicable for determining plant Si concentration across a range of plant species and growth forms, and represents a time- and cost-effective alternative to the chemical Si analysis methods. As NIRS can be applied concurrently to a range of plant organic constituents, it opens up unprecedented research possibilities for studying interrelations between Si and other plant compounds in vegetation, and for addressing the role of Si in ecosystems across a range of Si

  2. The GRAPHENE-SiC Substrate Interaction Enhanced Near-Infrared Absorption

    NASA Astrophysics Data System (ADS)

    Xu, X. G.; Yin, R.; Xu, G. J.; Cao, J. C.

    When epitaxially grown on silicon carbide, a single layer graphene will exhibit a finite energy bandgap like a conventional semiconductor, and its energy dispersion is no longer linear in momentum space in the low energy regime. In this paper, we present a quantitative analysis on the effect of the SiC substrate in the optical absorption of π-electrons in graphene. We calculated the absorption matrix element and the optical absorption in the near infrared even to the visible region by taking into account the SiC substrate effect. It has been found that the substrate effect can significantly enhance the optical absorption in graphene in the near-infrared region, even by up to 90%. It may be helpful to eliminate the previous discrepancy of optical transmission between the theoretical results and the experimental results in the near-infrared to the visible region.

  3. Enhanced visible and near-infrared capabilities of the JET mirror-linked divertor spectroscopy system

    SciTech Connect

    Lomanowski, B. A. Sharples, R. M.; Meigs, A. G.; Conway, N. J.; Zastrow, K.-D.; Heesterman, P.; Kinna, D. [EURATOM Collaboration: JET-EFDA Team

    2014-11-15

    The mirror-linked divertor spectroscopy diagnostic on JET has been upgraded with a new visible and near-infrared grating and filtered spectroscopy system. New capabilities include extended near-infrared coverage up to 1875 nm, capturing the hydrogen Paschen series, as well as a 2 kHz frame rate filtered imaging camera system for fast measurements of impurity (Be II) and deuterium Dα, Dβ, Dγ line emission in the outer divertor. The expanded system provides unique capabilities for studying spatially resolved divertor plasma dynamics at near-ELM resolved timescales as well as a test bed for feasibility assessment of near-infrared spectroscopy.

  4. Near-infrared photon time-of-flight spectroscopy of turbid materials up to 1400 nm.

    PubMed

    Svensson, Tomas; Alerstam, Erik; Khoptyar, Dmitry; Johansson, Jonas; Folestad, Staffan; Andersson-Engels, Stefan

    2009-06-01

    Photon time-of-flight spectroscopy (PTOFS) is a powerful tool for analysis of turbid materials. We have constructed a time-of-flight spectrometer based on a supercontinuum fiber laser, acousto-optical tunable filtering, and an InP/InGaAsP microchannel plate photomultiplier tube. The system is capable of performing PTOFS up to 1400 nm, and thus covers an important region for vibrational spectroscopy of solid samples. The development significantly increases the applicability of PTOFS for analysis of chemical content and physical properties of turbid media. The great value of the proposed approach is illustrated by revealing the distinct absorption features of turbid epoxy resin. Promising future applications of the approach are discussed, including quantitative assessment of pharmaceuticals, powder analysis, and calibration-free near-infrared spectroscopy. PMID:19566194

  5. Near infrared spectroscopy--investigations in neurovascular diseases.

    PubMed

    Schytz, Henrik Winther

    2015-12-01

    The purpose of this thesis was to explore and develop methods, where continuous wave near infrared spectroscopy (CW-NIRS) can be applied in different neurovascular diseases, in order to find biological markers that are useful in clinical neurology. To develop a new method to detect changes in cerebral blood flow (CBF), the first study investigated a multi-source detector separation configuration and indocyanine green (ICG) as a tracer to calculate a corrected blood flow index (BFI) value. The study showed no correlation between CBF changes measured by 133Xenon single photon emission computer tomography (133Xe-SPECT) and the corrected BFI value. It was concluded, that it was not possible to obtain reliable BFI data with the ICG CW-NIRS method. NIRS measurements of low frequency oscillations (LFOs) may be a reliable method to investigate vascular alterations in neurovascular diseases, but this requires an acceptable LFOs variation between hemispheres and over time in the healthy brain. The second study therefore investigated day-to-day and hemispheric variations in LFOs with NIRS. It was shown that NIRS might be useful in assessing LFOs between hemispheres, as well as interhemispheric phase and gain directly and over time. Migraine may be associated with persistent impairment of neurovascular coupling, but there is no experimental evidence to support this. The third study therefore investigated interictal neurovascular coupling during a mental task by a Stroop test in migraine without aura (MO) patients, which is the most common type of migraine. The study showed intact neurovascular coupling in the prefrontal cortex outside of attacks in patients with MO. The fourth study aimed to investigate possible changes in LFOs amplitude following nitric oxide (NO) donor infusion in familial hemiplegic migraine (FHM), which is a rare Mendelian subtype of migraine with aura. This study showed increased LFOs amplitude only in FHM patients with co-existing common type of migraine

  6. Near infrared laser penetration and absorption in human skin

    NASA Astrophysics Data System (ADS)

    Nasouri, Babak; Murphy, Thomas E.; Berberoglu, Halil

    2014-02-01

    For understanding the mechanisms of low level laser/light therapy (LLLT), accurate knowledge of light interaction with tissue is necessary. In this paper, we present a three dimensional, multi-layer Monte Carlo simulation tool for studying light penetration and absorption in human skin. The skin is modeled as a three-layer participating medium, namely epidermis, dermis, and subcutaneous, where its geometrical and optical properties are obtained from the literature. Both refraction and reflection are taken into account at the boundaries according to Snell's law and Fresnel relations. A forward Monte Carlo method was implemented and validated for accurately simulating light penetration and absorption in absorbing and anisotropically scattering media. Local profiles of light penetration and volumetric absorption densities were simulated for uniform as well as Gaussian profile beams with different spreads at 155 mW average power over the spectral range from 1000 nm to 1900 nm. The results show the effects of beam profiles and wavelength on the local fluence within each skin layer. Particularly, the results identify different wavelength bands for targeted deposition of power in different skin layers. Finally, we show that light penetration scales well with the transport optical thickness of skin. We expect that this tool along with the results presented will aid researchers resolve issues related to dose and targeted delivery of energy in tissues for LLLT.

  7. Near Infrared Spectroscopy of Jovian Trojan Asteroids: A Search for Silicate Features

    NASA Astrophysics Data System (ADS)

    Yang, Bin; Jewitt, D.

    2007-10-01

    Spectroscopic studies show that the reflectance spectra of Jovian Trojan asteroids generally appear to be linear and moderately red (with a few neutral ones) in the optical and near infrared wavelength regions. Cruikshank et al. (2001) demonstrated that synthetic models incorporating magnesium-rich pyroxene (Mg, Fe SiO3) and carbon could match the low albedo and the shape of the reflectance spectrum of Trojan Hektor from 0.3 to 3.6 micron. More importantly, Spitzer thermal emission spectra of three Trojan asteroids all showed an emissivity plateau near 10-micron, which was interpreted as an indication of fine-grained silicates (Emery et al. 2006). Interestingly, the previous survey (Howell 1995) noted that several Trojans showed a broad absorption band between 1.1 and 1.25 micron based on broadband infrared colors. This possible 1 micron feature is consistent with the 1 micron silicate band that has been observed and well studied on many main belt asteroids. We obtained near infrared (NIR) spectroscopy (0.8-2.5 micron) on 7 Trojan asteroids having reported silicate-related absorption bands. Also, the unique asteroid (279) Thule in the 3:4 mean-motion resonance was observed. The observations were made with the NASA Infrared Telescope Facility (IRTF) atop Mauna Kea. We will present the new spectra and simple scattering models employed to constrain the surface properties of Trojan asteroids.

  8. Thermal removal from near-infrared imaging spectroscopy data of the Moon

    USGS Publications Warehouse

    Clark, R.N.; Pieters, C.M.; Green, R.O.; Boardman, J.W.; Petro, N.E.

    2011-01-01

    In the near-infrared from about 2 ??m to beyond 3 ??m, the light from the Moon is a combination of reflected sunlight and emitted thermal emission. There are multiple complexities in separating the two signals, including knowledge of the local solar incidence angle due to topography, phase angle dependencies, emissivity, and instrument calibration. Thermal emission adds to apparent reflectance, and because the emission's contribution increases over the reflected sunlight with increasing wavelength, absorption bands in the lunar reflectance spectra can be modified. In particular, the shape of the 2 ??m pyroxene band can be distorted by thermal emission, changing spectrally determined pyroxene composition and abundance. Because of the thermal emission contribution, water and hydroxyl absorptions are reduced in strength, lowering apparent abundances. It is important to quantify and remove the thermal emission for these reasons. We developed a method for deriving the temperature and emissivity from spectra of the lunar surface and removing the thermal emission in the near infrared. The method is fast enough that it can be applied to imaging spectroscopy data on the Moon. Copyright ?? 2011 by the American Geophysical Union.

  9. High-resolution near-infrared spectroscopy of water dimer

    NASA Technical Reports Server (NTRS)

    Huang, Z. S.; Miller, R. E.

    1989-01-01

    High-resolution near-infrared spectra are reported for all of the O-H stretch vibrational bands of the water dimer. The four O-H vibrations are characterized as essentially independent proton-donor or proton-acceptor motions. In addition to the rotational and vibrational information contained in these spectra, details are obtained concerning the internal tunneling dynamics in both the ground and excited vibrational states. These results show that, for tunneling motions which involve the interchange of the proton donor and acceptor molecules, the associated frequencies decrease substantially due to vibrational excitation. The predissociation lifetimes for the various states of the dimer are determined from linewidth measurements. These results clearly show that the predissociation dynamics is strongly dependent on the tunneling states, as well as the Ka quantum number, indicating that the internal tunneling dynamics plays an important role in determining the dissociation rate in this complex.

  10. Follow-up in patients with subdural haematomas using near-infrared spectroscopy (NIRS)

    NASA Astrophysics Data System (ADS)

    Hennes, Hans-Juergen; Richter, Barbel; Lott, Carsten; Dick, Wolfgang; Boor, Stephan; Hanley, Daniel F.

    1998-12-01

    Secondary haemorrhage is an important cause of brain injury following initial therapy of subdural haematoma (SDH). Early identification and treatment of secondary haemorrhage improves neurologic outcome. Near infrared light at a wavelength of 760 nm shows a high absorption for haemoglobin. The difference in absorbance of light ((Delta) OD) at the wavelength of 760 nm between both hemispheres is measured to detect SDH. We have prospectively studied 20 patients with the CT diagnosis of SDH using near infrared spectroscopy (NIRS). Unilateral subdural haematomas were detected by NIRS in 15 out of 16 patients. Bilateral SDH were detected in 2 out of 3 patients. The median of (Delta) OD was reduced from initially 0.32 (0.05 - 0.85) to 0.1 (0.02 - 0.49) at hospital discharge. The complete resorption of the haematoma has been observed in 12 patients by NIRS. In 7 patients we still obtained pathologic values at discharge. The haematomas were not completely resolved, as proved by the CT scans prior to discharge. Our results showed repeated application of NIRS in patients with SDH help to document the clinical course after surgical treatment. Follow-up NIR evaluation of patients with SDH using NIRS may allow early treatment without time delay and a reduction of secondary brain injury as well as treatment costs.

  11. Near-infrared spectroscopy and pattern-recognition processing for classifying wines of two Italian provinces

    NASA Astrophysics Data System (ADS)

    Mignani, A. G.; Ciaccheri, L.; Gordillo, B.; Mencaglia, Andrea A.; González-Miret, M. L.; Heredia, F. J.; Cichelli, A.

    2014-05-01

    This paper presents an experiment making use of the near-infrared spectrum for distinguishing the wines produced in two close provinces of Abruzzo region of Italy. A collection of 32 wines was considered, 18 of which were produced in the province of Chieti, while the other 14 were from the province of Teramo. A conventional dual-beam spectrophotometer was used for absorption measurements in the 1300-1900 nm spectroscopic range. Principal Component Analysis was used for explorative analysis. Score maps in the PC1-PC2 or PC2-PC3 spaces were obtained, which successfully grouped the wine samples in two distinct clusters, corresponding to Chieti and Teramo provinces, respectively. A modelling of dual-band spectroscopy was also proposed, making use of two LEDs for illumination and a PIN detector instead of the spectrometer. These data were processed using Linear Discriminant Analysis which demonstrated satisfactory classification results.

  12. Note: Three wavelengths near-infrared spectroscopy system for compensating the light absorbance by water

    NASA Astrophysics Data System (ADS)

    Bhutta, M. Raheel; Hong, Keum-Shik; Kim, Beop-Min; Hong, Melissa Jiyoun; Kim, Yun-Hee; Lee, Se-Ho

    2014-02-01

    Given that approximately 80% of blood is water, we develop a wireless functional near-infrared spectroscopy system that detects not only the concentration changes of oxy- and deoxy-hemoglobin (HbO and HbR) during mental activity but also that of water (H2O). Additionally, it implements a water-absorption correction algorithm that improves the HbO and HbR signal strengths during an arithmetic task. The system comprises a microcontroller, an optical probe, tri-wavelength light emitting diodes, photodiodes, a WiFi communication module, and a battery. System functionality was tested by means of arithmetic-task experiments performed by healthy male subjects.

  13. Note: three wavelengths near-infrared spectroscopy system for compensating the light absorbance by water.

    PubMed

    Bhutta, M Raheel; Hong, Keum-Shik; Kim, Beop-Min; Hong, Melissa Jiyoun; Kim, Yun-Hee; Lee, Se-Ho

    2014-02-01

    Given that approximately 80% of blood is water, we develop a wireless functional near-infrared spectroscopy system that detects not only the concentration changes of oxy- and deoxy-hemoglobin (HbO and HbR) during mental activity but also that of water (H2O). Additionally, it implements a water-absorption correction algorithm that improves the HbO and HbR signal strengths during an arithmetic task. The system comprises a microcontroller, an optical probe, tri-wavelength light emitting diodes, photodiodes, a WiFi communication module, and a battery. System functionality was tested by means of arithmetic-task experiments performed by healthy male subjects. PMID:24593411

  14. A Weak Signal Extraction Method for Human Blood Glucose Noninvasive Measurement using Near Infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Li, Li-Na; Li, Qing-Bo; Zhang, Guang-Jun

    2009-11-01

    Background interference from optical absorption of matrix components, low spectral selectivity and low spectral sensitivity are the main interference factors for human blood glucose noninvasive measurement using near infrared (NIR) spectroscopy. In order to extract the weak glucose concentration information, a modified uninformative variable elimination (mUVE) method combined with successive projections algorithm (SPA) named as mUVE-SPA, is proposed. mUVE is used to eliminate matrix background and high-frequency noise by wavelet multi-resolution technology. SPA is followed to select variables with minimum colinearity by projection algorithm in a vector space. The proposed method was applied in two NIR spectra data sets (plasma samples experiment in vitro and human blood glucose noninvasive measurement experiment in vivo) respectively. The performance and adaptability of the proposed strategy were discussed. The results indicate that the proposed hybrid method can give an alternative path to extract weak glucose information and yield more parsimonious models with higher precision.

  15. Near Infrared Spectroscopy of Active Galactic Nuclei Using FSpec

    NASA Astrophysics Data System (ADS)

    Frechem, Joshua; Pessev, Peter

    2015-01-01

    Using data from the 2.3 meter Bok telescope on Kitt Peak and the FRANKENSpec spectrograph, we aim to investigate the circumnuclear region of over twenty active galaxies in the J, H, and K passbands in order to obtain high signal to noise spectra with reasonable investment of observing time. The sample is selected to cover a wide range of AGN types of activity in luminous nearby galaxies. The primary goal of this project was to sort and process the 9,000+ spectra, including dark subtraction, flat fielding, and creation of and application of bad pixel masks. The 2-D spectra were processed to a 1-D spectra and wavelength calibrated to reveal the exact wavelength of each peak in the spectra. Using standard stars is of utmost importance so the atmospheric lines can be corrected for and the data can be used for precise analysis. With the reduced and calibrated spectra, we measure the Paschen α, β, and γ Hydrogen lines, the Brackett γ Hydrogen line and the FeII line in the near infrared emitted from the circumnuclear regions of the galaxies. These data unveil details of what the environment is like in the area surrounding the supermassive black holes that are found in the heart of each of these galaxies.

  16. AKARI NEAR-INFRARED SPECTROSCOPY OF LUMINOUS INFRARED GALAXIES

    SciTech Connect

    Lee, Jong Chul; Lee, Myung Gyoon; Hwang, Ho Seong

    2012-09-01

    We present the AKARI near-infrared (NIR; 2.5-5 {mu}m) spectroscopic study of 36 (ultra)luminous infrared galaxies ((U)LIRGs) at z = 0.01-0.4. We measure the NIR spectral features including the strengths of 3.3 {mu}m polycyclic aromatic hydrocarbon emission and hydrogen recombination lines (Br{alpha} and Br{beta}), optical depths at 3.1 and 3.4 {mu}m, and NIR continuum slope. These spectral features are used to identify optically elusive, buried active galactic nuclei (AGNs). We find that half of the (U)LIRGs optically classified as non-Seyferts show AGN signatures in their NIR spectra. Using a combined sample of (U)LIRGs with NIR spectra in the literature, we measure the contribution of buried AGNs to the infrared luminosity from the spectral energy distribution fitting to the IRAS photometry. The contribution of these buried AGNs to the infrared luminosity is 5%-10%, smaller than the typical AGN contribution of (U)LIRGs including Seyfert galaxies (10%-40%). We show that NIR continuum slopes correlate well with WISE [3.4]-[4.6] colors, which would be useful for identifying a large number of buried AGNs using the WISE data.

  17. Quantitative Tissue Spectroscopy of Near Infrared Fluorescent Nanosensor Implants.

    PubMed

    Iverson, Nicole M; Bisker, Gili; Farias, Edgardo; Ivanov, Vsevolod; Ahn, Jiyoung; Wogan, Gerald N; Strano, Michael S

    2016-05-01

    Implantable, near infrared (nIR) fluorescent nanosensors are advantageous for in vivo monitoring of biological analytes since they can be rendered selective for a particular target molecule while utilizing their unique optical properties and the nIR tissue transparency window for information transfer without an internal power source or telemetry. However, basic questions remain regarding the optimal encapsulation platform, geometrical properties, and concentration ranges required for high signal to noise ratio and effective detection through biological tissue. In this work, we systematically explore these variables quantitatively to optimize the performance of such optical nanosensors for biomedical applications. We investigate both alginate and polyethylene glycol (PEG) as model hydrogel systems, encapsulating d(GT)15 ssDNA-wrapped single-walled carbon nanotubes (SWNT) as model fluorescent nanoparticle sensors, responsive to riboflavin. Hydrogel sensors implanted 0.5 mm into thick tissue samples exhibit 50% reduction of initial fluorescence intensity, allowing an optical detection limit of 5.4 mm and 5.1 mm depth in tissue for alginate and PEG gels, respectively, at a SWNT concentration of 10 mg L(-1), and 785 nm laser excitation of 80 mW and 30 s exposure. These findings are supported with in vivo nIR fluorescent imaging of SWNT hydrogels implanted subcutaneously in mice. For the case of SWNT, we find that the alginate system is preferable in terms of emission intensity, sensor response, rheological properties, and shelf life. PMID:27305824

  18. Predicting beef tenderness using near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Jeyamkondan, Subbiah; Kranzler, Glenn A.; Morgan, Brad J.; Rust, Sarah

    2004-03-01

    A near-infrared spectral reflectance system was developed and tested online to predict 14-day aged, cooked beef tenderness. A contact probe with a built-in tungsten-halogen light source supplied broadband light to the ribeye surface. Fiberoptics in the probe transmitted reflected light to a spectrometer with a spectral range of 400-2500 nm. In the first phase, steak samples (n=292) were brought from packing plants to the lab and scanned with the spectrometer. After scanning, samples were vacuum-packaged and aged for 14 days. They were then cooked in an impingement oven to an internal temperature of 70°C. Slice-shear force values were recorded for tenderness reference. In phase two, the spectrometer was modified for packing plant conditions. Spectral scans were obtained on-line on ribbed carcasses (n=276). A partial least square regression model was developed to predict tenderness scores from spectral reflectance. In phase three, the developed model was validated by scanning carcasses (n=200) on-line. The predicted shear-force values and samples were sent to the U.S. Meat Animal Research Center for third-party validation. At up to 70% certification levels, the system was able to successfully sort tough from tender carcasses.

  19. Near Infrared Spectroscopy of the Massive Protostar Orion-KL IRc2

    NASA Astrophysics Data System (ADS)

    Morino, J. I.; Hasegawa, T.; Yamashita, T.

    Using the multi-purpose near-infrared camera / spectrometer OASIS on the 1.9-m telescope at Okayama Astrophysical Observatory, we have done K-band spectroscopy of the diffuse continuum radiation found in the regions of the bipolar outflow of Orion-KL. The spectra show a very red continuum and clear CO band absorption at 2.3 micron, irrespective of the position in the bipolar outflow lobes. This radiation is most probably the light from the close vicinity of the protostar IRc2 scattered by the dust in the outflow. The fact that we see CO in ABSORPTION suggests that the CO features are of photospheric origin. If so, this is the first spectroscopy of a massive protostar driving an energetic outflow. Apart from the CO band, the continuum is very red and featureless. Comparison with spectra of giants and supergiants indicates that the photosphere of IRc2 has very low temperature and very large diameter; IRc2 is indeed a very young massive protostar, located close to the Hayashi's forbidden region in the HR diagram. We also measured a sample of luminous protostars driving bipolar flows. No CO absorption was detected in other sources, lending further support for the exceptional youth of IRc2.

  20. Enhanced near-infrared absorption in graphene with multilayer metal-dielectric-metal nanostructure.

    PubMed

    Zhang, Lei; Tang, Linlong; Wei, Wei; Cheng, Xinlu; Wang, Wei; Zhang, Hong

    2016-09-01

    A multilayer metal-dielectric-metal nanostructure is proposed to enhance the absorption in graphene in a near-infrared region. The main feature of the structure is the generation of strong magnetic response within the dielectric spacer, which is directly related to absorption enhancement in graphene to over 22 times higher than that of free-standing monolayer graphene. We also show that absorption enhancement in graphene can be easily controlled by adjusting the geometry of the propose structure. The simple structural configuration and the flexible tunability in absorption enhancement are beneficial for practical fabrication and future applications in graphene-based active optoelectronic devices. PMID:27607608

  1. Recent advances in the use of non-destructive near infrared spectroscopy on intact olive fruits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this review is to illustrate the state of the art in the use of non-destructive near infrared (NIR) spectroscopy for quality evaluation of intact fruit in the olive industry. First, the most recent studies regarding the application of non-destructive NIR spectroscopy methods to asse...

  2. Mid- Versus Near-Infrared Reflectance Spectroscopy for On-Site Determination of Soil Carbon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research has demonstrated that the determination of soil C diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) is often more accurate and produces more robust calibrations than near-infrared (NIR) reflectance spectroscopy (NIRS) when analyzing ground, dry soils. DRIFTS is also not ...

  3. Combined autofluorescence and Raman spectroscopy method for skin tumor detection in visible and near infrared regions

    NASA Astrophysics Data System (ADS)

    Zakharov, V. P.; Bratchenko, I. A.; Artemyev, D. N.; Myakinin, O. O.; Khristoforova, Y. A.; Kozlov, S. V.; Moryatov, A. A.

    2015-07-01

    The combined application of Raman and autofluorescence spectroscopy in visible and near infrared regions for the analysis of malignant neoplasms of human skin was demonstrated. Ex vivo experiments were performed for 130 skin tissue samples: 28 malignant melanomas, 19 basal cell carcinomas, 15 benign tumors, 9 nevi and 59 normal tissues. Proposed method of Raman spectra analysis allows for malignant melanoma differentiating from other skin tissues with accuracy of 84% (sensitivity of 97%, specificity of 72%). Autofluorescence analysis in near infrared and visible regions helped us to increase the diagnostic accuracy by 5-10%. Registration of autofluorescence in near infrared region is realized in one optical unit with Raman spectroscopy. Thus, the proposed method of combined skin tissues study makes possible simultaneous large skin area study with autofluorescence spectra analysis and precise neoplasm type determination with Raman spectroscopy.

  4. Broadband on-chip near-infrared spectroscopy based on a plasmonic grating filter array.

    PubMed

    Li, Erwen; Chong, Xinyuan; Ren, Fanghui; Wang, Alan X

    2016-05-01

    We demonstrate an ultra-compact, broadband on-chip near-infrared (NIR) spectroscopy system based on a narrow-band plasmonic filter array. The entire filter array, consisting of 28 individual subwavelength metallic gratings, was monolithically integrated in a thin gold film on a quartz substrate, covering a 270 nm spectra from 1510 nm to 1780 nm. In order to achieve a high spectral resolution, extremely narrow slits are created for the gratings with a polymer waveguide layer on top, generating narrow-band guided-mode resonances through coupling with the surface-plasmon resonances of the metallic gratings. Experimental results show that the transmission bands of the filter array have full width at half-maximum of only 7 nm-13 nm, which is sufficient for NIR spectroscopy. The NIR absorption spectroscopy of xylene using the on-chip plasmonic filter array matches very well with the results from conventional Fourier transform infrared spectroscopy, which proves the great potential for NIR sensing applications. PMID:27128037

  5. [Application of near-infrared diffuse reflectance spectroscopy to the detection and identification of transgenic corn].

    PubMed

    Rui, Yu-kui; Luo, Yun-bo; Huang, Kun-lun; Wang, Wei-min; Zhang, Lu-da

    2005-10-01

    With the rapid development of the GMO, more and more GMO food has been pouring into the market. Much attention has been paid to GMO labeling under the controversy of GMO safety. Transgenic corns and their parents were scanned by continuous wave of near infrared diffuse reflectance spectroscopy range of 12000-4000 cm(-1); the resolution was 4 cm(-1); scanning was carried out for 64 times; BP algorithm was applied for data processing. The GMO food was easily resolved. Near-infrared diffuse reflectance spectroscopy is unpolluted and inexpensive compared with PCR and ELISA, so it is a very promising detection method for GMO food. PMID:16395887

  6. Compensating the Degradation of Near-Infrared Absorption of Black Silicon Caused by Thermal Annealing.

    PubMed

    Wang, Yanchao; Gao, Jinsong; Yang, Haigui; Wang, Xiaoyi; Shen, Zhenfeng

    2016-12-01

    We propose the use of thin Ag film deposition to remedy the degradation of near-infrared (NIR) absorption of black Si caused by high-temperature thermal annealing. A large amount of random and irregular Ag nanoparticles are formed on the microstructural surface of black Si after Ag film deposition, which compensates the degradation of NIR absorption of black Si caused by thermal annealing. The formation of Ag nanoparticles and their contributions to NIR absorption of black Si are discussed in detail. PMID:26831694

  7. π-Extended "Earring" Porphyrins with Multiple Cavities and Near-Infrared Absorption.

    PubMed

    Rao, Yutao; Kim, Taeyeon; Park, Kyu Hyung; Peng, Fulei; Liu, Lei; Liu, Yunmei; Wen, Bin; Liu, Shubin; Kirk, Steven Robert; Wu, Licheng; Chen, Bo; Ma, Ming; Zhou, Mingbo; Yin, Bangshao; Zhang, Yuexing; Kim, Dongho; Song, Jianxin

    2016-05-23

    β,β-tripyrrin-bridged earring porphyrins were synthesized through Suzuki-Miyaura cross coupling reactions. These porphyrinoids have multiple cavities and can accommodate two or three metal ions per molecule. The structures of the porphyrins have been elucidated by x-ray diffraction analysis, and feature curved π planes. The electronic spectra of the porphyrins exhibit near-infrared (NIR) absorptions and metal insertion leads to red-shifted and intensified absorption features. Electrochemical analysis and transient absorption measurements indicated that the porphyrins exhibit effective electronic communication between their central and peripheral moieties. PMID:27038255

  8. Research on content measurement of textile mixture by near infrared spectroscopy based on principal component regression

    NASA Astrophysics Data System (ADS)

    Yan, Li; Liu, Li

    2010-07-01

    A new method for accurate measurement of content of textile mixture by use of Fourier transform near infrared spectroscopy is put forward. The near infrared spectra of 56 samples with different cotton and polyester contents were obtained, in which 41 samples, 10 samples and 5 samples were used for the calibration set, validation set and prediction set respectively. Principal component analysis (PCA) was utilized for the spectra data compression. Principal component regression (PCR) model was developed. It indicates that the MAE is within 2.9% and the RMSE is less than 3.6% for the validation samples, which is suitable for the prediction of unknown samples. The PCR model was applied to predict unknown samples. Experimental results show that this approach by use of Fourier transform Near Infrared Spectroscopy can be used to quantitative analysis for textile fiber.

  9. Quantitative analysis of peanut oil content in ternary blended edible oil using near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Chen, Huacai; Liu, Fuli; Wang, Zhilan; Jin, Shangzhong

    2008-03-01

    Calibration models of quantitative analysis of peanut oil content in ternary blended edible oil by near infrared spectroscopy were built using partial least square (PLS) regression. A total of 92 samples blended with three kinds of pure oil in different proportion (V/V) were prepared. Near infrared diffuse reflectance spectra of the samples were collected over 4 000 cm -1-10 000 cm -1 spectral region with a FT-NIR spectrometer. A calibration model of prediction to the peanut oil content was established with PLS using the original spectra and validated with leave-one-out cross validation method. The correlation coefficient and the RMSEC of the model were 0.9926 and 2.91%, respectively. The result showed that near infrared spectroscopy could be an ideal tool for fast determination to the peanut oil content in blended edible oil.

  10. Portable microcontroller-based instrument for near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Giardini, Mario E.; Corti, Mario; Lago, Paolo; Gelmetti, Andrea

    2000-05-01

    Near IR Spectroscopy (NIRS) can be employed to noninvasively and continuously measure in-vivo local changes in haemodynamics and oxygenation of human tissues. In particular, the technique can be particularly useful for muscular functional monitoring. We present a portable NIRS research-grade acquisition system prototype, strictly dedicate to low-noise measurements during muscular exercise. The prototype is able to control four LED sources and a detector. Such a number of sources allows for multipoint measurements or for multi-wavelength spectroscopy of tissue constituents other than oxygen, such as cytochrome aa3 oxidation. The LEDs and the detector are mounted on separate probes, which carry also the relevant drivers and preamplifiers. By employing surface-mount technologies, probe size and weight are kept to a minimum. A single-chip mixed-signal RISC microcontroller performs source-to- detector multiplexing with a digital correlation technique. The acquired data are stored on an on-board 64 K EEPROM bank, and can be subsequently uploaded to a personal computer via serial port for further analysis. The resulting instrument is compact and lightweight. Preliminary test of the prototype on oxygen consumption during tourniquet- induced forearm ischaemia show adequate detectivity and time response.

  11. Near infrared spectroscopy for fibre based gas detection

    NASA Astrophysics Data System (ADS)

    Stewart, George; Johnstone, Walter; Thursby, Graham; Culshaw, Brian

    2010-04-01

    Gas sensing systems based on fibre optic linked near infra red absorption cells are potentially a flexible and effective tool for monitoring accumulations of hazardous and noxious gases in enclosed areas such as tunnels and mines. Additionally the same baseline technology is readily modified to measure concentrations of hydrocarbon fuels - notably but not exclusively methane, and monitoring emissions of greenhouse gases. Furthermore the system can be readily implemented to provide intrinsically safe monitoring over extensive areas at up to ~250 points from a single interrogation unit. In this paper we review our work on fibre coupled gas sensing systems. We outline the basic principles through which repeatable and accurate self calibrating gas measurements may be realised, including the recover of detailed line shapes for non contact temperature and / or pressure measurements in addition to concentration assessments in harsh environments. We also outline our experience in using these systems in extensive networks operating under inhospitable conditions over extended periods extending to several years.

  12. Near-infrared spectroscopy of the Sun and HD 20010. Compiling a new line list in the near-infrared

    NASA Astrophysics Data System (ADS)

    Andreasen, D. T.; Sousa, S. G.; Delgado Mena, E.; Santos, N. C.; Tsantaki, M.; Rojas-Ayala, B.; Neves, V.

    2016-01-01

    Context. Effective temperature, surface gravity, and metallicity are basic spectroscopic stellar parameters necessary to characterize a star or a planetary system. Reliable atmospheric parameters for FGK stars have been obtained mostly from methods that rely on high resolution and high signal-to-noise optical spectroscopy. The advent of a new generation of high resolution near-infrared (NIR) spectrographs opens the possibility of using classic spectroscopic methods with high resolution and high signal-to-noise in the NIR spectral window. Aims: We compile a new iron line list in the NIR from a solar spectrum to derive precise stellar atmospheric parameters, comparable to the ones already obtained from high resolution optical spectra. The spectral range covers 10 000 Å to 25 000 Å , which is equivalent to the Y,J,H, and K-bands. Methods: Our spectroscopic analysis is based on the iron excitation and ionization balance done in local thermodynamic equilibrium. We use a high resolution and high signal-to-noise ratio spectrum of the Sun from the Kitt Peak telescope as a starting point to compile the iron line list. The oscillator strengths (log gf) of the iron lines were calibrated for the Sun. The abundance analysis was done using the MOOG code after measuring equivalent widths of 357 solar iron lines. Results: We successfully derived stellar atmospheric parameters for the Sun. Furthermore, we analysed HD 20010, a F8IV star, from which we derived stellar atmospheric parameters using the same line list as for the Sun. The spectrum was obtained from the CRIRES-POP database. The results are compatible with the values found in the literature, confirming the reliability of our line list. However, we obtain large errors due to the quality of the data. Full Table 1 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/585/A143

  13. Far-red to near infrared emission and scattering spectroscopy for biomedical applications

    NASA Astrophysics Data System (ADS)

    Zhang, Gang

    2001-06-01

    The thesis investigates the far-red and near infrared (NIR) spectral region from biomedical tissue samples for monitoring the state of tissues. The NIR emission wing intensity is weak in comparison to the emission in the visible spectral region. The wing emission from biomedical samples has revealed meaningful information about the state of the tissues. A model is presented to explain the shape of the spectral wing based on a continuum of energy levels. The wing can be used to classify different kinds of tissues; especially it can be used to differentiate cancer part from normal human breast tissues. The research work of the far-red emission from thermal damaged tissue samples shows that the emission intensity in this spectral region is proportional to the extent of the thermal damage of the tissue. Near infrared spectral absorption method is used to investigate blood hemodynamics (perfusion and oxygenation) in brain during sleep-wake transition. The result of the research demonstrates that the continuous wave (CW) type near infrared spectroscopy (NIRS) device can be used to investigate brain blood perfusion and oxygenation with a similar precision with frequency domain (FD) type device. The human subject sleep and wake transition, has been monitored by CW type NIRS instrument with traditional electroencephalograph (EEG) method. Parallel change in oxy-Hb and deoxy-Hb is a discrete event that occurs in the transition from both sleep to wakefulness and wakefulness to sleep. These hemodynamic switches are generally about few seconds delayed from the human decided transition point between sleep and wake on the polygraph EEG recording paper. The combination of NIRS and EEG methods monitor the brain activity, gives more information about the brain activity. The sleep apnea investigation was associated with recurrent apneas, insufficient nasal continuous positive airway pressure (CPAP) and the different response of the peripheral and central compartments to breathing

  14. Near-infrared spectroscopy and hyperspectral imaging: non-destructive analysis of biological materials.

    PubMed

    Manley, Marena

    2014-12-21

    Near-infrared (NIR) spectroscopy has come of age and is now prominent among major analytical technologies after the NIR region was discovered in 1800, revived and developed in the early 1950s and put into practice in the 1970s. Since its first use in the cereal industry, it has become the quality control method of choice for many more applications due to the advancement in instrumentation, computing power and multivariate data analysis. NIR spectroscopy is also increasingly used during basic research performed to better understand complex biological systems, e.g. by means of studying characteristic water absorption bands. The shorter NIR wavelengths (800-2500 nm), compared to those in the mid-infrared (MIR) range (2500-15 000 nm) enable increased penetration depth and subsequent non-destructive, non-invasive, chemical-free, rapid analysis possibilities for a wide range of biological materials. A disadvantage of NIR spectroscopy is its reliance on reference methods and model development using chemometrics. NIR measurements and predictions are, however, considered more reproducible than the usually more accurate and precise reference methods. The advantages of NIR spectroscopy contribute to it now often being favoured over other spectroscopic (colourimetry and MIR) and analytical methods, using chemicals and producing chemical waste, such as gas chromatography (GC) and high performance liquid chromatography (HPLC). This tutorial review intends to provide a brief overview of the basic theoretical principles and most investigated applications of NIR spectroscopy. In addition, it considers the recent development, principles and applications of NIR hyperspectral imaging. NIR hyperspectral imaging provides NIR spectral data as a set of images, each representing a narrow wavelength range or spectral band. The advantage compared to NIR spectroscopy is that, due to the additional spatial dimension provided by this technology, the images can be analysed and visualised as

  15. Absorption and electrochromic modulation of near-infrared light: realized by tungsten suboxide

    NASA Astrophysics Data System (ADS)

    Li, Guilian; Zhang, Shouhao; Guo, Chongshen; Liu, Shaoqin

    2016-05-01

    In the present study, needle-like tungsten suboxide W18O49 nanocrystals were fabricated as the optical active substance to realize the aim of optical control of near-infrared light. The W18O49 nanocrystals were selected in this regard due to their unique optical performance. As revealed by the powder absorption result, the needle-like W18O49 nanocrystals show strong and wide photoabsorption in the entire near infrared region of 780-2500 nm, from which thin films with the W18O49 nanocrystal coating thus benefits and can strongly shield off almost all near infrared irradiation, whereas transmitting the majority of visible light. To make it more tunable, the W18O49 nanocrystals were finally assembled onto an ITO glass via the layer-by-layer strategy for later electrochromic investigation. The nanostructured architectures of the W18O49 nanocrystal electrochromic films exhibit high contrast, faster switching response, higher coloration efficiencies (150 cm2 C-1 at 650 nm and 255 cm2 C-1 at 1300 nm), better long-term redox switching stability (reversibility of 98% after 500 cycles) and wide electrochromic spectrum coverage of both the visible and infrared regions.In the present study, needle-like tungsten suboxide W18O49 nanocrystals were fabricated as the optical active substance to realize the aim of optical control of near-infrared light. The W18O49 nanocrystals were selected in this regard due to their unique optical performance. As revealed by the powder absorption result, the needle-like W18O49 nanocrystals show strong and wide photoabsorption in the entire near infrared region of 780-2500 nm, from which thin films with the W18O49 nanocrystal coating thus benefits and can strongly shield off almost all near infrared irradiation, whereas transmitting the majority of visible light. To make it more tunable, the W18O49 nanocrystals were finally assembled onto an ITO glass via the layer-by-layer strategy for later electrochromic investigation. The nanostructured

  16. Detection of sucrose content of sugar beet by visible/near-infrared spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sucrose content is the most important quality parameter in the production and processing of sugar beet. This paper reports on the application of visible/near-infrared (Vis-NIR) spectroscopy for measurement of the sucrose content of sugar beet. Two portable spectrometers, covering the spectral region...

  17. NEAR-INFRARED TRANSMISSION AND REFLECTANCE SPECTROSCOPY FOR DETERMINATION OF DIETARY FIBER IN BARLEY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Near-infrared (NIR) transmission and reflectance spectroscopy were investigated as rapid screening tools to evaluate the total dietary fiber content of barley. The Foss Grainspec Rice Analyzer and the NIR Systems 6500 monochromator were used to obtain transmission and reflectance spectra, respectiv...

  18. MEASUREMENT OF TOTAL DIETARY FIBER IN MILLED BARLEY USING NEAR-INFRARED TRANSMITTANCE SPECTROSCOPY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whole-grain milled barley (n=56) was scanned using a near-infrared transmittance spectroscopy (NIT)(850-1048nm) and total dietary fiber (TDF) was determined for each cultivar by AOAC enzymatic-gravimetric method (Method 991.43). The validation statistics of PLS models using calibration (n=28) and v...

  19. Use of visible and near-infrared spectroscopy to predict pork longissimus lean color stability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated using visible and near-infrared (VIS/NIR) spectroscopy to predict lean color stability in pork loin chops. Spectra were collected immediately following and approximately 1 h after rib removal from 1,208 loins. Loins were aged for 14 d before a 2.54-cm chop was placed in simula...

  20. A near-infrared spectroscopy routine for unambiguous identification of cryptic ant species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The identification of species – of importance for most biological disciplines – is not always straightforward as cryptic species present a hurdle for traditional species discrimination. Fibre-optic near-infrared spectroscopy (NIRS) is a rapid and cheap method for a wide range of different applicatio...

  1. Visible and Near-Infrared Spectroscopy Detects Honey Bee Queen Insemination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The abdomens of honey bee queens, the heads of worker bees, and the ventriculi of worker bees were analyzed by visible and near-infrared spectroscopy. Mated honey bee queens could be distinguished from virgin queens by their spectra with 100% accuracy. Also, the heads of worker bees taken from the ...

  2. Visible/near-infrared spectroscopy to predict water holding capacity in broiler breast meat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Visible/Near-infrared spectroscopy (Vis/NIRS) was examined as a tool for rapidly determining water holding capacity (WHC) in broiler breast meat. Both partial least squares (PLS) and principal component analysis (PCA) models were developed to relate Vis/NIRS spectra of 85 broiler breast meat sample...

  3. Integrating Near Infrared Spectroscopy (NIR) into the USDA-ARS sugarcane breeding program in Houma, LA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Near Infrared Spectroscopy (NIRs) is a relatively new technique that has the potential to benefit Louisiana’s sugarcane industry, and is being successfully used in other parts of the world (e.g., South Africa) and even Florida. Recently, the USDA-ARS in Houma, LA purchased a NIR Cane Presentation Sy...

  4. Prefrontal Dysfunction in Attention-Deficit/Hyperactivity Disorder as Measured by Near-Infrared Spectroscopy

    ERIC Educational Resources Information Center

    Negoro, Hideki; Sawada, Masayuki; Iida, Junzo; Ota, Toyosaku; Tanaka, Shohei; Kishimoto, Toshifumi

    2010-01-01

    Recent developments in near-infrared spectroscopy (NIRS) have enabled non-invasive clarification of brain functions in psychiatric disorders with measurement of hemoglobin concentrations as cerebral blood volume. Twenty medication-naive children with attention-deficit/hyperactivity disorder (ADHD) and 20 age- and sex-matched healthy control…

  5. Visible and near-infrared spectroscopy detects queen honey bee insemination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The abdomens of honey bee queens, the heads of worker bees, and the ventriculi of worker bees were analyzed by visible and near-infrared spectroscopy. Mated honey bee queens could be distinguished from virgin queens by their spectra with 100% accuracy. Also, the heads of worker bees taken from the...

  6. NEAR INFRARED IMAGING SPECTROSCOPY FOR DETECTING NEW AND OLD BRUISES ON APPLES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this research was to investigate the potential of near-infrared (NIR) imaging spectroscopy for detecting new and old bruises on apple fruit in the spectral region between 900 nm and 1700 nm. Experiments were conducted to acquire hyperspectral image cubes from Red Delicious and Gold...

  7. Near-infrared transmission and reflectance spectroscopy for the measurement of dietary fiber in barley

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Near-infrared (NIR) transmission and reflectance spectroscopy were investigated as rapid screening tools to evaluate the total dietary fiber content of barley (Hordeum vulgare L.) cultivars. A Foss Grainspec Rice Analyzer and an NIR Systems 6500 spectrometer were used to obtain transmission and ref...

  8. Development of near-infrared spectroscopy calibrations to measure quality characteristics in intact Brassicaceae germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Determining seed quality parameters is an integral part of cultivar improvement and germplasm screening. However, quality tests are often time cnsuming, seed destructive, and can require large seed samples. This study describes the development of near-infrared spectroscopy (NIRS) calibrations to mea...

  9. Abdominal near-infrared spectroscopy measurements are lower in preterm infants at risk for necrotizing enterocolitis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Near-infrared spectroscopy is a noninvasive method of measuring local tissue oxygenation (StO[2]). Abdominal StO[2] measurements in preterm piglets are directly correlated with changes in intestinal blood flow and markedly reduced by necrotizing enterocolitis. The objectives of this study were to us...

  10. Functional Near-Infrared Spectroscopy for the Assessment of Speech Related Tasks

    ERIC Educational Resources Information Center

    Dieler, A. C.; Tupak, S. V.; Fallgatter, A. J.

    2012-01-01

    Over the past years functional near-infrared spectroscopy (fNIRS) has substantially contributed to the understanding of language and its neural correlates. In contrast to other imaging techniques, fNIRS is well suited to study language function in healthy and psychiatric populations due to its cheap and easy application in a quiet and natural…

  11. Determination of sucrose content in sugar beet by portable visible and near-infrared spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The feasibility of visible and near-infrared spectroscopy for measurement of the sucrose content of sugar beet was investigated with two portable spectrometers that cover the spectral regions of 400-1,100 nm and 900-1,600 nm, respectively. Spectra in interactance mode were collected first from 398 i...

  12. Quantification of rosmarinic acid levels by near infrared spectroscopy in laboratory culture grown spearmint plantlets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A method for the rapid quantization of rosmarinic acid (RA) in tissues of spearmint using near-infrared (NIR) spectroscopy was developed by correlating with the results of methanol extracts analyzed on a HPLC photo-diode array (PDA) system. NIR and HPLC analyses performed on over 500 samples were u...

  13. Visible/near-infrared spectroscopy for discrimination of HLB-infected citrus leaves from healthy leaves

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Researchers have used various hyperspectral systems, covering several areas of the electromagnetic spectrum to investigate all types of disease/plant interactions. The purpose of this research was to investigate using visible and near-infrared (400-1100nm) spectroscopy to differentiate HLB infected...

  14. Data fusion of visible/near-infrared spectroscopy and spectral scattering for apple quality assessment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Visible/near-infrared (VNIR) spectroscopy and spectral scattering are based on different sensing principles, and they have shown different abilities for predicting apple fruit firmness and soluble solids content (SSC). Hence the two techniques could work synergistically to improve the quality predic...

  15. Approaching total absorption at near infrared in a large area monolayer graphene by critical coupling

    SciTech Connect

    Liu, Yonghao; Chadha, Arvinder; Zhao, Deyin; Shuai, Yichen; Menon, Laxmy; Yang, Hongjun; Zhou, Weidong; Piper, Jessica R.; Fan, Shanhui; Jia, Yichen; Xia, Fengnian; Ma, Zhenqiang

    2014-11-03

    We demonstrate experimentally close to total absorption in monolayer graphene based on critical coupling with guided resonances in transfer printed photonic crystal Fano resonance filters at near infrared. Measured peak absorptions of 35% and 85% were obtained from cavity coupled monolayer graphene for the structures without and with back reflectors, respectively. These measured values agree very well with the theoretical values predicted with the coupled mode theory based critical coupling design. Such strong light-matter interactions can lead to extremely compact and high performance photonic devices based on large area monolayer graphene and other two–dimensional materials.

  16. Enhancement of near-infrared absorption in graphene with metal gratings

    SciTech Connect

    Zhao, B.; Zhang, Z. M.; Zhao, J. M.

    2014-07-21

    Graphene has been demonstrated as a good candidate for ultrafast optoelectronic devices. However, graphene is essentially transparent in the visible and near infrared with an absorptivity of 2.3%, which has largely limited its application in photon detection. This Letter demonstrates that the absorptance in a monatomic graphene layer can be greatly enhanced to nearly 70%, thanks to the localized strong electric field resulting from magnetic resonances in deep metal gratings. Furthermore, the resonance frequency is essentially not affected by the additional graphene layer. The method presented here may benefit the design of next-generation graphene-based optical and optoelectronic devices.

  17. Age dependency of cerebral oxygenation assessed with near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Colier, Willy N.; van Haaren, Nicole J.; van de Ven, Marjo J.; Folgering, Hans T.; Oeseburg, Berend

    1997-04-01

    Near-IR spectroscopy (NIRS) is an optical technique that provides information on cerebral tissue oxygenation and hemodynamics on a continuous, direct, and noninvasive basis. It is used to determine cerebral blood volume (CBV) and cerebrovascular CO2 reactivity during normoxic hyper- and hypocapnia in a group of 28 healthy volunteers aged 20 to 83 years. The main focus is on to the age dependency of the measured variables. The influence of changes in minute ventilation during normocapnia on the cerebral oxygenation was also studied. The mean CBV in age was, for 20 to 30 years, 2.14 +/- 0.51 ml/100 g of brain tissue; for 45 to 50 years, 1.92 +/- 0.40 ml/100 g; and for 70 to 83 years, 1.47 +/- 0.55 ml/100 g. The CBV showed a significant decease with advancing age. No influence was found for a change in minute ventilation on cerebral oxygenation. During hypercapnia cerebral blood flow (CBF) significantly increased in al age groups, with a factor of 1.31 +/- 0.17 kPa-1, 1.64 +/- 1.39 kPa-1, and 2.4 +/- 1.7 kPa-1, respectively, for the three age groups. The difference in change among the age groups was not statistically significant. The trend seen was an increased change in CBF with advancing age. During hypocapnia, the CBF significantly decreased in all age groups, with a factor of 0.89 +/- 0.08 kPa-1, 0.89 +/- 0.04 kPa-1, and 0.85 +/- 0.11 kPa-1, respectively. There was no significant difference among the age groups.

  18. Challenging near infrared spectroscopy discriminating ability for counterfeit pharmaceuticals detection.

    PubMed

    Storme-Paris, I; Rebiere, H; Matoga, M; Civade, C; Bonnet, P-A; Tissier, M H; Chaminade, P

    2010-01-25

    This study was initiated by the laboratories and control department of the French Health Products Safety Agency (AFSSAPS) as part of the fight against the public health problem of rising counterfeit and imitation medicines. To test the discriminating ability of Near InfraRed Spectroscopy (NIRS), worse cases scenarios were first considered for the discrimination of various pharmaceutical final products containing the same Active Pharmaceutical Ingredient (API) with different excipients, such as generics of proprietary medicinal products (PMP). Two generic databases were explored: low active strength hard capsules of Fluoxetine and high strength tablets of Ciprofloxacin. Then 4 other cases involving suspicious samples, counterfeits and imitations products were treated. In all these cases, spectral differences between samples were studied, giving access to API or excipient contents information, and eventually allowing manufacturing site identification. A chemometric background is developed to explain the optimisation methodology, consisting in the choices of appropriate pretreatments, algorithms for data exploratory analyses (unsupervised Principal Component Analysis), and data classification (supervised cluster analysis, and Soft Independent Modelling of Class Analogy). Results demonstrate the high performance of NIRS, highlighting slight differences in formulations, such as 2.5% (w/w) in API strength, 1.0% (w/w) in excipient and even coating variations (<1%, w/w) with identical contents, approaching the theoretical limits of NIRS sensitivity. All the different generic formulations were correctly discriminated and foreign PMP, constituted of formulations slightly different from the calibration ones, were also all discriminated. This publication addresses the ability of NIRS to detect counterfeits and imitations and presents the NIRS as an ideal tool to master the global threat of counterfeit drugs. PMID:20103090

  19. Intensity-modulated near-infrared spectroscopy: instrument design issues

    NASA Astrophysics Data System (ADS)

    Alford, Ken; Wickramasinghe, Yappa A.

    2000-05-01

    Tissue oxygenation instruments which rely on phase sensitive detection suffer form phase-amplitude crosstalk, i.e. the phase of the detected signal with respect to a reference signal is dependent on the average intensity of the light entering the photomultiplier tube (PMT). If an instrument that detects the phase of the scattered signal is to yield the phase accuracy required in order to provide useful clinical parameters, quantitative haemoglobin and oxy- haemoglobin concentrations (Hb), and (HbO2) and mixed arterial-venous saturation all sources of phase-amplitude effects must be understood. The phase-amplitude effect has in the past been attributed to the fact that the rise time of the detector decreases with increasing light intensity. In this work an additional phase-amplitude effect in intensity modulated near IR spectroscopy (IMNIRS) instrumentation is studied. The presence of a coherent interfering signal due to low level RF coupling at the detector output will corrupt the phase of the signal of interest and cause a phase-amplitude effect. Under certain conditions a relatively low level interfering RF signal can introduce a significant error in the slope of the phase per unit distance plot. A comparison between measured and modeled phase distortion is presented and ways to reduce the effect discussed. In addition to phase-amplitude effects, the final accuracy of the quantitative measurements made by an IMNIRS instrument depends heavily on the calibration. Calibration of the measured phase and the AC and DC components of the detected light must take into account distortions due to, (a) phase-amplitude crosstalk and system phase offset, (b) detector non-linearities, (c) variation in laser source intensity and phase with time and temperature, (d) optical probe light loss and (e) variations in detector sensitivity. Current instrument performance will be presented and discussed.

  20. [The research progress in determining lignocellulosic content by near infrared reflectance spectroscopy technology].

    PubMed

    Du, Juan; An, Dong; Xia, Tian; Huang, Yan-Hua; Li, Hong-Chao; Zhang, Yun-Wei

    2013-12-01

    Near infrared reflectance spectroscopy technology, as a new analytic method, can be used to determine the content of lignin, cellulose and hemi-cellulose which is faster, effective, easier to operate, and more accurate than the traditional wet chemical methods. Nowadays it has been widely used in measuring the composition of lignocelluloses in woody plant and herbaceous plant. The domestic and foreign research progress in determining the lignin, cellulose and hemi-cellulose content in woody plant ( wood and bamboo used as papermaking raw materials and wood served as potential biomass energy) and herbaceous plant (forage grass and energy grass) by near infrared reflectance spectroscopy technology is comprehensively summarized and the advances in method studies of measuring the composition of lignocelluloses by near infrared reflectance spectroscopy technology are summed up in three aspects, sample preparation, spectral data pretreatment and wavelength selection methods, and chemometric analysis respectively. Four outlooks are proposed combining the development statues of wood, forage grass and energy grass industry. First of all, the authors need to establish more feasible and applicable models for a variety of uses which can be used for more species from different areas, periods and anatomical parts. Secondly, comprehensive near infrared reflectance spectroscopy data base of grass products quality index needs to be improved to realize on-line quality and process control in grassproducts industry, which can guarantee the quality of the grass product. Thirdly, the near infrared reflectance spectroscopy quality index model of energy plant need to be built which can not only contribute to breed screening, but also improve the development of biomass industry. Besides, modeling approaches are required to be explored and perfected any further. Finally, the authors need to try our best to boost the advancement in the determination method of lignin, cellulose and hemi

  1. Cerebral and Muscle Tissue Oxygenation During Incremental Cycling in Male Adolescents Measured by Time-Resolved Near-Infrared Spectroscopy.

    PubMed

    Ganesan, Goutham; Leu, Szu-Yun; Cerussi, Albert; Tromberg, Bruce; Cooper, Dan M; Galassetti, Pietro

    2016-05-01

    Near-infrared spectroscopy has long been used to measure tissue-specific O2 dynamics in exercise, but most published data have used continuous wave devices incapable of quantifying absolute Hemoglobin (Hb) concentrations. We used time-resolved near-infrared spectroscopy to study exercising muscle (Vastus Lateralis, VL) and prefrontal cortex (PFC) Hb oxygenation in 11 young males (15.3 ± 2.1 yrs) performing incremental cycling until exhaustion (peak VO2 = 42.7 ± 6.1 ml/min/kg, mean peak power = 181 ± 38 W). Time-resolved near-infrared spectroscopy measurements of reduced scattering (μs´) and absorption (μa) at three wavelengths (759, 796, and 833 nm) were used to calculate concentrations of oxyHb ([HbO2]), deoxy Hb ([HbR]), total Hb ([THb]), and O2 saturation (stO2). In PFC, significant increases were observed in both [HbO2] and [HbR] during intense exercise. PFC stO2% remained stable until 80% of total exercise time, then dropped (-2.95%, p = .0064). In VL, stO2% decreased until peak time (-6.8%, p = .01). Segmented linear regression identified thresholds for PFC [HbO2], [HbR], VL [THb]. There was a strong correlation between timing of second ventilatory threshold and decline in PFC [HbO2] (r = .84). These findings show that time-resolved near-infrared spectroscopy can be used to study physiological threshold phenomena in children during maximal exercise, providing insight into tissue specific hemodynamics and metabolism. PMID:26451845

  2. Dissolved Gas-in-Oil Analysis in Transformers Based on Near-Infrared Photoacoustic Spectroscopy

    NASA Astrophysics Data System (ADS)

    Mao, Xuefeng; Zhou, Xinlei; Zhai, Liang; Yu, Qingxu

    2015-06-01

    This paper investigates an application of near-infrared photoacoustic spectroscopy (PAS) to analyze the dissolved gas-in-oil of a transformer. A near-infrared tunable fiber laser-based PAS system has been developed. Using this system, the gas detection limits (signal-to-noise ratio = 1) of 4 ppb at 1531.59 nm for , 39 ppm at 1565.98 nm for CO, and 34 ppm at 1572.34 are reached. In addition, the fault gas () is produced by a transformer spatial discharge simulation system, and the productivity of the gas is measured quantitatively. The experiment demonstrates the near-infrared PAS system is able to be applied to the dissolved gas analysis of a transformer.

  3. Absorption and electrochromic modulation of near-infrared light: realized by tungsten suboxide.

    PubMed

    Li, Guilian; Zhang, Shouhao; Guo, Chongshen; Liu, Shaoqin

    2016-05-01

    In the present study, needle-like tungsten suboxide W18O49 nanocrystals were fabricated as the optical active substance to realize the aim of optical control of near-infrared light. The W18O49 nanocrystals were selected in this regard due to their unique optical performance. As revealed by the powder absorption result, the needle-like W18O49 nanocrystals show strong and wide photoabsorption in the entire near infrared region of 780-2500 nm, from which thin films with the W18O49 nanocrystal coating thus benefits and can strongly shield off almost all near infrared irradiation, whereas transmitting the majority of visible light. To make it more tunable, the W18O49 nanocrystals were finally assembled onto an ITO glass via the layer-by-layer strategy for later electrochromic investigation. The nanostructured architectures of the W18O49 nanocrystal electrochromic films exhibit high contrast, faster switching response, higher coloration efficiencies (150 cm(2) C(-1) at 650 nm and 255 cm(2) C(-1) at 1300 nm), better long-term redox switching stability (reversibility of 98% after 500 cycles) and wide electrochromic spectrum coverage of both the visible and infrared regions. PMID:27119556

  4. Measurements of the rate constant of HOsub2 + NOsub2 + Nsub2 --> HOsub2NOsub2 + Nsub2 using near-infrared wavelength-modulation spectroscopy and UV-visible absorption spectroscopy

    NASA Technical Reports Server (NTRS)

    Christensen, L. E.; Okumura, M.; Sander, S. P.; Friedl, R. R.; Miller, C. E.; Sloan, J. J.

    2004-01-01

    Rate coefficients for the reaction HO(sub 2)+ NO(sub 2) + N(sub 2) --> HO(sub 2)NO(sub 2) + N(sub 2) (reaction 1) were measured using simultaneous near-IR and UV spectroscopy from 220 to 298 K and from 45 to 200 Torr.

  5. [Rapid determination of fatty acids in soybean oils by transmission reflection-near infrared spectroscopy].

    PubMed

    Song, Tao; Zhang, Feng-ping; Liu, Yao-min; Wu, Zong-wen; Suo, You-rui

    2012-08-01

    In the present research, a novel method was established for determination of five fatty acids in soybean oil by transmission reflection-near infrared spectroscopy. The optimum conditions of mathematics model of five components (C16:0, C18:0, C18:1, C18:2 and C18:3) were studied, including the sample set selection, chemical value analysis, the detection methods and condition. Chemical value was analyzed by gas chromatography. One hundred fifty eight samples were selected, 138 for modeling set, 10 for testing set and 10 for unknown sample set. All samples were placed in sample pools and scanned by transmission reflection-near infrared spectrum after sonicleaning for 10 minute. The 1100-2500 nm spectral region was analyzed. The acquisition interval was 2 nm. Modified partial least square method was chosen for calibration mode creating. Result demonstrated that the 1-VR of five fatty acids between the reference value of the modeling sample set and the near infrared spectrum predictive value were 0.8839, 0.5830, 0.9001, 0.9776 and 0.9596, respectively. And the SECV of five fatty acids between the reference value of the modeling sample set and the near infrared spectrum predictive value were 0.42, 0.29, 0.83, 0.46 and 0.21, respectively. The standard error of the calibration (SECV) of five fatty acids between the reference value of testing sample set and the near infrared spectrum predictive value were 0.891, 0.790, 0.900, 0.976 and 0.942, respectively. It was proved that the near infrared spectrum predictive value was linear with chemical value and the mathematical model established for fatty acids of soybean oil was feasible. For validation, 10 unknown samples were selected for analysis by near infrared spectrum. The result demonstrated that the relative standard deviation between predict value and chemical value was less than 5.50%. That was to say that transmission reflection-near infrared spectroscopy had a good veracity in analysis of fatty acids of soybean oil

  6. Construction of Models for Nondestructive Prediction of Ingredient Contents in Blueberries by Near-infrared Spectroscopy Based on HPLC Measurements.

    PubMed

    Bai, Wenming; Yoshimura, Norio; Takayanagi, Masao; Che, Jingai; Horiuchi, Naomi; Ogiwara, Isao

    2016-01-01

    Nondestructive prediction of ingredient contents of farm products is useful to ship and sell the products with guaranteed qualities. Here, near-infrared spectroscopy is used to predict nondestructively total sugar, total organic acid, and total anthocyanin content in each blueberry. The technique is expected to enable the selection of only delicious blueberries from all harvested ones. The near-infrared absorption spectra of blueberries are measured with the diffuse reflectance mode at the positions not on the calyx. The ingredient contents of a blueberry determined by high-performance liquid chromatography are used to construct models to predict the ingredient contents from observed spectra. Partial least squares regression is used for the construction of the models. It is necessary to properly select the pretreatments for the observed spectra and the wavelength regions of the spectra used for analyses. Validations are necessary for the constructed models to confirm that the ingredient contents are predicted with practical accuracies. Here we present a protocol to construct and validate the models for nondestructive prediction of ingredient contents in blueberries by near-infrared spectroscopy. PMID:27404089

  7. Absorption intensity tunability in the near infrared region using phase-change nanostructure (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Ozdemir, Abdurrahman; Saraydemir, Safak; Barut, Bilal; Kocer, Hasan

    2015-08-01

    Nanostructured thin film absorbers embedded with phase-change material (PCM) can provide large level of absorption intensity tunability in the near-infrared region. Germanium Antimonide Tellurite (Ge2Sb1Te4-GST) was employed as the phase-change material in the designed structures. The structure is composed of a periodic grating-type array of 200 nm thick Au buried with 100 nm-thick GST layer from the top of the Au layer. The period of the gratings is 2 μm and in each period, GST width is 0.5 μm. GST was selected as the active PCM because its optical properties undergo a substantial change during a structural transition from the amorphous to the crystalline phase. The optical absorption properties of the designed structures with respect to the geometric and material parameters were systematically investigated using finite-difference time-domain computations. It was shown that absorption intensity in the near-infrared region was tuned from the near-perfect to the near-zero level by switching the PCM from its amorphous to crystalline states. The distributions of the electric field and absorbed power at the resonant wavelengths with respect to different phases of the GST were investigated to further explain the physical origin of the absorption tuning. This study provides a path toward the realization of tunable infrared absorbers for the applications, such as selective infrared emitters, infrared camouflage, sensors, and photovoltaic devices.

  8. [Near infrared reflectance spectroscopy (NIRS) and its application in the determination for the quality of animal feed and products].

    PubMed

    Wang, Li; Meng, Qing-Xiang; Ren, Li-Ping; Yang, Jian-Song

    2010-06-01

    Near-infrared reflectance spectroscopy (NIRS) has been the most rapidly developing and noticeable spectrographic analytical technique in recent years. The determining principle and progresses of near-infrared reflectance spectroscopy are presented briefly. It mainly includes the progresses in pre-processing technique and analyzing model of near-infrared reflectance spectroscopy. Two pre-processing techniques, including differential coefficient-dealt with technique, the signal-smoothing technique, and four analyzing models of near-infrared spectroscopy, including the multiplied lined regression (MLR), principal component analysis (PCA), partial least squares (PLS), and artificial nerve network (ANN). The application of near-infrared reflectance spectroscopy to the first time. The investigation of reviewed papers shows that the near-infrared reflectance spectroscopy is widely applied in feed analysis and animal products analysis because of its rapidness, non-destruction and non-pollution. The near infrared reflectance spectroscopy has been used to determine the feed common ingredient, such as dry matter, crude protein, crude fiber, crude fat and so on, micro-components including amino acid, vitamin, and noxious components, and to determine the physical and chemical properties of animal products which including egg, mutton, beef and pork. Details of the analytical characteristics of feed and animal products described in the reviewed papers are given. New trends and limits to the application of near-infrared reflectance spectroscopy in these fields are also discussed. PMID:20707134

  9. Towards a low-cost mobile subcutaneous vein detection solution using near-infrared spectroscopy.

    PubMed

    Juric, Simon; Flis, Vojko; Debevc, Matjaz; Holzinger, Andreas; Zalik, Borut

    2014-01-01

    Excessive venipunctures are both time- and resource-consuming events, which cause anxiety, pain, and distress in patients, or can lead to severe harmful injuries. We propose a low-cost mobile health solution for subcutaneous vein detection using near-infrared spectroscopy, along with an assessment of the current state of the art in this field. The first objective of this study was to get a deeper overview of the research topic, through the initial team discussions and a detailed literature review (using both academic and grey literature). The second objective, that is, identifying the commercial systems employing near-infrared spectroscopy, was conducted using the PubMed database. The goal of the third objective was to identify and evaluate (using the IEEE Xplore database) the research efforts in the field of low-cost near-infrared imaging in general, as a basis for the conceptual model of the upcoming prototype. Although the reviewed commercial devices have demonstrated usefulness and value for peripheral veins visualization, other evaluated clinical outcomes are less conclusive. Previous studies regarding low-cost near-infrared systems demonstrated the general feasibility of developing cost-effective vein detection systems; however, their limitations are restricting their applicability to clinical practice. Finally, based on the current findings, we outline the future research direction. PMID:24883388

  10. Towards a Low-Cost Mobile Subcutaneous Vein Detection Solution Using Near-Infrared Spectroscopy

    PubMed Central

    Flis, Vojko; Debevc, Matjaz; Holzinger, Andreas; Zalik, Borut

    2014-01-01

    Excessive venipunctures are both time- and resource-consuming events, which cause anxiety, pain, and distress in patients, or can lead to severe harmful injuries. We propose a low-cost mobile health solution for subcutaneous vein detection using near-infrared spectroscopy, along with an assessment of the current state of the art in this field. The first objective of this study was to get a deeper overview of the research topic, through the initial team discussions and a detailed literature review (using both academic and grey literature). The second objective, that is, identifying the commercial systems employing near-infrared spectroscopy, was conducted using the PubMed database. The goal of the third objective was to identify and evaluate (using the IEEE Xplore database) the research efforts in the field of low-cost near-infrared imaging in general, as a basis for the conceptual model of the upcoming prototype. Although the reviewed commercial devices have demonstrated usefulness and value for peripheral veins visualization, other evaluated clinical outcomes are less conclusive. Previous studies regarding low-cost near-infrared systems demonstrated the general feasibility of developing cost-effective vein detection systems; however, their limitations are restricting their applicability to clinical practice. Finally, based on the current findings, we outline the future research direction. PMID:24883388

  11. Structure analysis of aromatic medicines containing nitrogen using near-infrared spectroscopy and generalized two-dimensional correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Liu, Hao; Gao, Hongbin; Qu, Lingbo; Huang, Yanping; Xiang, Bingren

    2008-12-01

    Four aromatic medicines (acetaminophen; niacinamide; p-aminophenol; nicotinic acid) containing nitrogen were investigated by FT-NIR (Fourier transform near-infrared) spectroscopy and generalized two-dimensional (2D) correlation spectroscopy. The FT-NIR spectra were measured over a temperature range of 30-130 °C. By combining near-infrared spectroscopy, generalized 2D correlation spectroscopy and references, the molecular structures (especially the hydrogen bond related with nitrogen) were analyzed and the NIR band assignments were performed. The results will be helpful to the understanding of aromatic medicines containing nitrogen and the utility of these substances.

  12. Remote Identification of Pyroclastic Deposits on Mars and the Moon with Near-Infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Horgan, B. H.; Chojnacki, M.; Lai, J. C.; Bennett, K. A.; Bell, J. F.

    2013-12-01

    A major challenge for interpreting the volcanic history of the terrestrial planets is differentiating effusive from explosive volcanic deposits, especially when these deposits are only exposed in cross section. One major difference between these deposits is the presence of glass. Pyroclastic flows and other explosive deposits can contain large quantities of glass, depending on factors including water content at the time of eruption, whereas glass is largely restricted to the fragile cooling rind in effusive deposits. Thus, the presence of significant glass in a deposit most likely indicates an explosive origin. Here we present a new method for discriminating lava flows from pyroclastic deposits using near-infrared spectroscopy. Iron-bearing glass exhibits a broad and shallow absorption band due to iron in the glass structure, centered between 1.10-1.18 μm. This band is longward of similar bands caused by other Fe-bearing phases (e.g., olivine and pyroxene), and therefore allows unique identification of glass where it is present at high abundances (>80 wt.% of Fe-bearing phases). Lower abundances of glass in a mixture with other Fe-bearing phases can still be detected based on the effects of the glass absorption band, which shifts the 1 μm band center and causes a high asymmetry in the shape of the band, both toward longer wavelengths. By analyzing near-infrared spectra from the Mars Express OMEGA imaging spectrometer for these 1 μm band characteristics consistent with Fe-bearing glass, we have mapped the distribution of glass-bearing deposits globally on Mars at 1 km resolution. Where available, we have confirmed our detections with high resolution observations from the MRO CRISM imaging spectrometer (18-36 m/pixel). Glass is a component of many dune fields, in sediments derived from local erosion of layered units, in the widespread dark sediments in the northern plains, and in deposits associated with linear features (possible fissures). These results suggest a

  13. Compositional analysis of protein content in milk with near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Bi, Weihong; Yang, Xiaoli; Li, Chao; Liu, Haiying

    2006-02-01

    A fast analytical method was introduced based on near-infrared (NIR) technology in this paper. The protein content was measured in short order using the near-infrared transmission spectroscopy (1000-1700nm) of milk. There were several waves of milk's NIR spectroscopy selected. By correlating the spectrum data of the waves selected and the protein content in milk, a calibration model was established. The protein content could be measured by importing the spectrum data to the calibration model. In this model there were several parameters, which were the spectrum data of the waves selected. Then, the method how to select the waves best was introduced and the characteristic waves of milk were selected by utilizing genetic algorithm. A partial least squares (PLS) regression model between the spectroscopy and the protein content was presented for milk samples, and the predictive repeatability was also researched.

  14. Identification of oil spills by near-infrared spectroscopy (NIR) and support vector machine (SVM)

    NASA Astrophysics Data System (ADS)

    Bi, Weihong; Tan, Ailing; Zhao, Yong; Gao, Meijing

    2009-11-01

    The identification of the spilled oil is an essential and important part in the investigation and handling of oil spill accidents. The combination of near-infrared spectroscopy (NIR) and chemometrics is ideal for such a situation. NIR spectroscopy is a powerful and effective technique and qualitative information can be obtained with classification models. Support vector machines (SVM) have been introduced recently in chemometrics and have proven to be powerful in NIR spectra classification tasks, such as material identification and food discrimination. In this work, the SVM is utilized to classify near infrared spectroscopy of simulated spilled oils of gasoline, diesel fuel and kerosene on the marine. A good classification performance is obtained :the identification rate were 100%, 96% and 98% on the test sets respectively.

  15. Application of near infrared spectroscopy (NIRS) to non-destructive internal quality inspection of tomatoes

    NASA Astrophysics Data System (ADS)

    Tao, Xuemei; He, Yong

    2006-09-01

    The internal quality of tomato such as acidity and sugar content is important to its taste thus influences the market. The objective of this paper was to demonstrate the feasibility of using a near-infrared spectroscopy (NIRS) to investigate the relationship between sugar content and acidity of tomato and absorption spectra. The N1RS reflectance of nondestructive tomatoes was measured with a Visible/NJR spectrophotometer in 325-1075 nm range. The sugar content and acidity of tomato were obtained with a handhold sugar content meter and a PH meter. The reflectance data set was recorded and analyzed with some mathematic methods. The PLS (Partial least squares) calibration method was developed for converting the NIRS reflectance of tomato into the data which determined the acidity value. BP (Back propagation) neural network was used to set up the relationship between the NIRS reflectance of tomato and sugar content. The acidity values were detected with an accuracy of 9O% and the sugar contents determined by the BP network were also very close to the measurements (coefficient of correlation r2=0.8764). NW spectra analysis would be very useful in the nondestructive internal quality inspecting of tomato.

  16. Detection of canine skin and subcutaneous tumors by visible and near-infrared diffuse reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    Cugmas, Blaž; Plavec, Tanja; Bregar, Maksimilijan; Naglič, Peter; Pernuš, Franjo; Likar, Boštjan; Bürmen, Miran

    2015-03-01

    Cancer is the main cause of canine morbidity and mortality. The existing evaluation of tumors requires an experienced veterinarian and usually includes invasive procedures (e.g., fine-needle aspiration) that can be unpleasant for the dog and the owner. We investigate visible and near-infrared diffuse reflectance spectroscopy (DRS) as a noninvasive optical technique for evaluation and detection of canine skin and subcutaneous tumors ex vivo and in vivo. The optical properties of tumors and skin were calculated in a spectrally constrained manner, using a lookup table-based inverse model. The obtained optical properties were analyzed and compared among different tumor groups. The calculated parameters of the absorption and reduced scattering coefficients were subsequently used for detection of malignant skin and subcutaneous tumors. The detection sensitivity and specificity of malignant tumors ex vivo were 90.0% and 73.5%, respectively, while corresponding detection sensitivity and specificity of malignant tumors in vivo were 88.4% and 54.6%, respectively. The obtained results show that the DRS is a promising noninvasive optical technique for detection and classification of malignant and benign canine skin and subcutaneous tumors. The method should be further investigated on tumors with common origin.

  17. Accurate optical parameter extraction procedure for broadband near-infrared spectroscopy of brain matter

    PubMed Central

    Najafizadeh, Laleh; Gandjbakhche, Amir H.; Pourrezaei, Kambiz; Daryoush, Afshin

    2013-01-01

    Abstract. Modeling behavior of broadband (30 to 1000 MHz) frequency modulated near-infrared (NIR) photons through a phantom is the basis for accurate extraction of optical absorption and scattering parameters of biological turbid media. Photon dynamics in a phantom are predicted using both analytical and numerical simulation and are related to the measured insertion loss (IL) and insertion phase (IP) for a given geometry based on phantom optical parameters. Accuracy of the extracted optical parameters using finite element method (FEM) simulation is compared to baseline analytical calculations from the diffusion equation (DE) for homogenous brain phantoms. NIR spectroscopy is performed using custom-designed, broadband, free-space optical transmitter (Tx) and receiver (Rx) modules that are developed for photon migration at wavelengths of 680, 780, and 820 nm. Differential detection between two optical Rx locations separated by 0.3 cm is employed to eliminate systemic artifacts associated with interfaces of the optical Tx and Rx with the phantoms. Optical parameter extraction is achieved for four solid phantom samples using the least-square-error method in MATLAB (for DE) and COMSOL (for FEM) simulation by fitting data to measured results over broadband and narrowband frequency modulation. Confidence in numerical modeling of the photonic behavior using FEM has been established here by comparing the transmission mode’s experimental results with the predictions made by DE and FEM for known commercial solid brain phantoms. PMID:23322361

  18. Optical analysis of cirrhotic liver by near infrared time resolved spectroscopy

    NASA Astrophysics Data System (ADS)

    Nishio, Toshihiro; Kitai, Toshiyuki; Miwa, Mitsuharu; Takahashi, Rei; Yamaoka, Yoshio

    1999-10-01

    The severity of liver cirrhosis was related with the optical properties of liver tissue. Various grades of liver cirrhosis were produced in rats by intraperitoneal injection of thioacetamide (TAA) for different periods: 4 weeks, 8 weeks, 12 weeks, and 16 weeks. Optical properties of the liver, absorption, coefficient ((mu) a) and scattering coefficient (microsecond(s) '), were measured by near-infrared time- resolved spectroscopy. Histological examination confirmed cirrhotic changes in the liver, which were more severe in rats with TAA administration for longer periods. The (mu) a increased in 4- and 8-week rats, and then decreased in 12- and 16-week rats. The (mu) a of blood-free liver decreased as liver cirrhosis progressed. The hemoglobin content in the liver calculated from the (mu) a values increased in 4- and 8-week rats and decreased in 12- and 16-week rats. The microsecond(s) ' decreased in the cirrhotic liver, probably reflecting the decrease in the mitochondria content. It was shown that (mu) a and microsecond(s) ' determination is useful to assess the severity of liver cirrhosis.

  19. Multidistance probe arrangement to eliminate artifacts in functional near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Yamada, Toru; Umeyama, Shinji; Matsuda, Keiji

    2009-11-01

    Functional near-infrared spectroscopy has the potential to easily detect cerebral functional hemodynamics. However, in practical fNIRS measurements, a subject's physical or systemic physiological activities often cause undesirable artifacts. Such activities can be evoked even by task execution. In this case, observed artifacts may correlate strongly with the task sequence, and it is difficult to eliminate them by conventional signal filtering techniques. We present a theoretical analysis and Monte Carlo simulations of layered media in which both scattering and absorption changes occur, and show that a multidistance probe arrangement is effective in removing artifacts and extracting functional hemodynamics. The probe arrangement is determined based on simulation results. Artifacts induced by nonfunctional tasks (body tilting, head nodding, and breath holding) are clearly observed when a conventional method is used; such artifacts are appreciably reduced by the proposed method. Signals evoked by single-sided finger movements are observed at both hemispheres when we use a conventional method. On the other hand, localized signals at the primary motor area are observed by the proposed method. A statistically significant increase in oxygenated hemoglobin and decrease in deoxygenated hemoglobin are simultaneously observed at the contralateral primary motor area.

  20. A versatile femtosecond stimulated Raman spectroscopy setup with tunable pulses in the visible to near infrared

    SciTech Connect

    Zhu, Liangdong; Liu, Weimin; Fang, Chong

    2014-07-28

    We demonstrate a versatile and efficient setup to perform femtosecond stimulated Raman spectroscopy (FSRS). Technical innovations are implemented to achieve the wavelength tunability for both the picosecond narrowband Raman pump pulse and femtosecond broadband Raman probe pulse. Using a simplified one-grating scheme in a home-built second harmonic bandwidth compressor followed by a two-stage noncollinear optical parametric amplifier, we tune the Raman pump pulse from ca. 480 to 750 nm. To generate the suitable Raman probe pulse in tandem, we rely on our recently demonstrated broadband up-converted multicolor array technique that readily provides tunable broadband laser sidebands across the visible to near-infrared range. This unique setup has unparalleled flexibility for conducting FSRS. We measure the ground-state Raman spectra of a cyclohexane standard using tunable pump-probe pairs at various wavelengths across the visible region. The best spectral resolution is ∼12 cm{sup −1}. By tuning the pump wavelength closer to the electronic absorption band of a photoacid pyranine in water, we observe the pre-resonantly enhanced Raman signal. The stimulated Raman gain of the 1627 cm{sup −1} mode is increased by over 15 times.

  1. [Clustering analysis applied to near-infrared spectroscopy analysis of Chinese traditional medicine].

    PubMed

    Liu, Mu-qing; Zhou, De-cheng; Xu, Xin-yuan; Sun, Yao-jie; Zhou, Xiao-li; Han, Lei

    2007-10-01

    The present article discusses the clustering analysis used in the near-infrared (NIR) spectroscopy analysis of Chinese traditional medicines, which provides a new method for the classification of Chinese traditional medicines. Samples selected purposely in the authors' research to measure their absorption spectra in seconds by a multi-channel NIR spectrometer developed in the authors' lab were safrole, eucalypt oil, laurel oil, turpentine, clove oil and three samples of costmary oil from different suppliers. The spectra in the range of 0.70-1.7 microm were measured with air as background and the results indicated that they are quite distinct. Qualitative mathematical model was set up and cluster analysis based on the spectra was carried out through different clustering methods for optimization, and came out the cluster correlation coefficient of 0.9742 in the authors' research. This indicated that cluster analysis of the group of samples is practicable. Also it is reasonable to get the result that the calculated classification of 8 samples was quite accorded with their characteristics, especially the three samples of costmary oil were in the closest classification of the clustering analysis. PMID:18306778

  2. An in vitro hemodynamic tissue model to study the variations in flow using near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Ranga, Raghavender; Kashyap, Dheerendra; Behbehani, Khosrow; Liu, Hanli

    2005-04-01

    Determination of blood flow changes will be helpful for evaluation of tumor prognosis and therapy. Our study is to develop an in vitro hemodynamic phantom model, which allows us to show the feasibility of using near infrared spectroscopy (NIRS) to determine flow changes as a dynamic imaging modality to monitor tumor responses to therapy. In the hemodynamic phantom model, both single and multiple, transparent, plastic tubes were used to pass through a cylindral glass chamber. The chamber was filled with either an Intralipid solution or a soft gelatin phantom, while the tube or tubes were pumped with either an Intralipid-ink mixture or animal whole blood to simulate the tumor vasculature. The Intralipid solutions that were filled in the chamber and tubes had optical scattering and absorption properties similar to those of tumor tissues and tumor vasculature. A single-channel, broadband, NIRS system with a tungsten light source and a CCD-array spectrometer was used to quantify the changes in optical density (OD) of the intralipid-ink mixture with variations in flow rate and concentration. A single-exponential curve fit has been used to determine the time constant (τ) from the change in OD to estimate the flow rate. The obtained preliminary results show a strong correlation between changing rates of concentration and flow; a multivariable dynamic mathematical model may be also established to relate changes of Hb, HbO and blood volume with blood flow.

  3. Improved depth resolution in near-infrared diffuse reflectance spectroscopy using obliquely oriented fibers

    NASA Astrophysics Data System (ADS)

    Thilwind, Rachel Estelle; 't Hooft, Gert; Uzunbajakava, Natallia E.

    2009-03-01

    We demonstrate a significant improvement of depth selectivity when using obliquely oriented fibers for near-infrared (NIR) diffuse reflectance spectroscopy. This is confirmed by diffuse reflectance measurements of a two-layer tissue-mimicking phantom across the spectral range from 1000 to 1940 nm. The experimental proof is supported by Monte Carlo simulations. The results reveal up to fourfold reduction in the mean optical penetration depth, twofold reduction in its variation, and a decrease in the number of scattering events when a single fiber is oriented at an angle of 60 deg. The effect of reducing the mean optical penetration depth is enhanced by orienting both fibers inwardly. Using outwardly oriented fibers enables more selective probing of deeper layers, while reducing the contribution from surface layers. We further demonstrate that the effect of an inward oblique arrangement can be approximated to a decrease in fiber-to-fiber separation in the case of a perpendicular fiber arrangement. This approximation is valid in the weak- or absorption-free regime. Our results assert the advantages of using obliquely oriented fibers when attempting to specifically address superficial tissue layers, for example, for skin cancer detection, or in noninvasive glucose monitoring. Such flexibility could be further advantageous in a range of minimally invasive applications, including catheter-based interventions.

  4. Detection of canine skin and subcutaneous tumors by visible and near-infrared diffuse reflectance spectroscopy.

    PubMed

    Cugmas, Blaž; Plavec, Tanja; Bregar, Maksimilijan; Naglič, Peter; Pernuš, Franjo; Likar, Boštjan; Bürmen, Miran

    2015-03-01

    Cancer is the main cause of canine morbidity and mortality. The existing evaluation of tumors requires an experienced veterinarian and usually includes invasive procedures (e.g., fine-needle aspiration) that can be unpleasant for the dog and the owner. We investigate visible and near-infrared diffuse reflectance spectroscopy (DRS) as a noninvasive optical technique for evaluation and detection of canine skin and subcutaneous tumors ex vivo and in vivo. The optical properties of tumors and skin were calculated in a spectrally constrained manner, using a lookup table-based inverse model. The obtained optical properties were analyzed and compared among different tumor groups. The calculated parameters of the absorption and reduced scattering coefficients were subsequently used for detection of malignant skin and subcutaneous tumors. The detection sensitivity and specificity of malignant tumors ex vivo were 90.0% and 73.5%, respectively, while corresponding detection sensitivity and specificity of malignant tumors in vivo were 88.4% and 54.6%, respectively. The obtained results show that the DRS is a promising noninvasive optical technique for detection and classification of malignant and benign canine skin and subcutaneous tumors. The method should be further investigated on tumors with common origin. PMID:25751030

  5. Determining the composition of ammonia/water mixtures using short-wave near-infrared spectroscopy.

    PubMed

    Barba, M Isabel; Salavera, Daniel; Larrechi, M Soledad; Coronas, Alberto

    2016-01-15

    This paper proposes a methodology based on short-wave near-infrared spectroscopy to determine the ammonia content of ammonia/water mixtures with ammonia mass fraction in the range 0.35-0.65. Establishing this methodology meant modeling the relationship between the pressure bar (15-25)bar, temperature (20-50)°C and composition of the ammonia-water in the mixture (0.35-0.65 in ammonia mass fraction) with absorbance at 1033nm. The experiments were designed to optimize experimental work. A 2(3) factorial design+3 center points was used to establish and analyze the significance of the variables in the absorbance using analysis of variance (ANOVA). A linear model for absorbance was obtained using the least squares method. The trueness of the results versus the values obtained was assessed using a reference method; density measurement was chosen for this study. The accuracy of the results in terms of root-mean-square deviation (RMSD) was 3.7%. The methodology proposed represents a fast alternative for the "in-situ" measurement of the ammonia composition of ammonia-water mixtures in absorption refrigeration systems. PMID:26592584

  6. The use of muscle near-infrared spectroscopy in sport, health and medical sciences: recent developments.

    PubMed

    Hamaoka, Takafumi; McCully, Kevin K; Niwayama, Masatsugu; Chance, Britton

    2011-11-28

    Near-infrared spectroscopy (NIRS) has been shown to be one of the tools that can measure oxygenation in muscle and other tissues in vivo. This review paper highlights the progress, specifically in this decade, that has been made for evaluating skeletal muscle oxygenation and oxidative energy metabolism in sport, health and clinical sciences. Development of NIRS technologies has focused on improving quantification of the signal using multiple wavelengths to solve for absorption and scattering coefficients, multiple pathlengths to correct for the influence of superficial skin and fat, and time-resolved and phase-modulated light sources to determine optical pathlengths. In addition, advances in optical imaging with multiple source and detector pairs as well as portability using small wireless detectors have expanded the usefulness of the devices. NIRS measurements have provided information on oxidative metabolism in various athletes during localized exercise and whole-body exercise, as well as training-induced adaptations. Furthermore, NIRS technology has been used in the study of a number of chronic health conditions. Future developments of NIRS technology will include enhancing signal quantification. In addition, advances in NIRS imaging and portability promise to transform how measurements of oxygen utilization are obtained in the future. PMID:22006908

  7. Relationship between blood oxygenation and lactate in human skeletal muscle revealed by near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Xu, Guodong; Luo, Qingming; Ge, Xinfa; Gong, Hui; Zeng, Shaoqun

    2002-04-01

    Near-infrared spectroscopy (NIRS) is a focus of attention in the research field of biomedical photonics. The concentration of HbO2 in human skeletal muscle has been measured noninvasive NIRS using a portable tissue oximeter continuously when the subjects did incremental exercises on a power bicycle. Blood lactate is one of traditional physical research subjects which is applied most widely. We study blood volume in the tissue of sportsmen when they are subjected by the incremental physical load, simultaneously detecting some parameters such as the heart rate, maximal oxygen absorption and the concentration of blood lactate. As the intensity of exercises was heightened, the concentration of blood lactate and blood volume in tissue increased, while the concentration of HbO2 decreased. Thus the rudimental characteristics of energy consumption and supply during hypoxia and aerobic exercises are investigated. By discovering the relationship between blood lactate in human skeletal muscle and blood oxygenation, a novel approach for measuring blood lactate noninvasively and assessing the sports ability could be provided. Furthermore, it is possible to assess the fatigue state with tissue oximeter to monitor the human sports intensity noninvasively and dynamically.

  8. Algorithm for removing scalp signals from functional near-infrared spectroscopy signals in real time using multidistance optodes

    NASA Astrophysics Data System (ADS)

    Kiguchi, Masashi; Funane, Tsukasa

    2014-11-01

    A real-time algorithm for removing scalp-blood signals from functional near-infrared spectroscopy signals is proposed. Scalp and deep signals have different dependencies on the source-detector distance. These signals were separated using this characteristic. The algorithm was validated through an experiment using a dynamic phantom in which shallow and deep absorptions were independently changed. The algorithm for measurement of oxygenated and deoxygenated hemoglobins using two wavelengths was explicitly obtained. This algorithm is potentially useful for real-time systems, e.g., brain-computer interfaces and neuro-feedback systems.

  9. Cell damage in near-infrared multimode optical traps as a result of multiphoton absorption

    NASA Astrophysics Data System (ADS)

    König, K.; Liang, H.; Berns, M. W.; Tromberg, B. J.

    1996-07-01

    We report on cell damage of single cells confined in continuous-wave (cw), near-infrared (NIR) multimode optical traps as a result of multiphoton absorption phenomena. Trapping beams at NIR wavelengths less than 800 nm are capable of damaging cells through a two-photon absorption process. Cell damage is more pronounced in multimode cw traps compared with single-frequency true cw NIR traps because of transient power enhancement by longitudinal mode beating. Partial mode locking in tunable cw Ti:sapphire lasers used as trapping beam sources can produce unstable subnanosecond pulses at certain wavelengths that amplify multiphoton absorption effects significantly. We recommend the use of single-frequency long-wavelength NIR trapping beams for optical micromanipulation of vital cells.

  10. Using near-infrared spectroscopy to resolve the species, gender, age, and the presence of Wolbachia infection in laboratory-reared Drosophila

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of the study was to determine the accuracy of near-infrared spectroscopy (NIRS) in determining species, gender, age and the presence of the common endosymbiont Wolbachia in laboratory reared Drosophila. NIRS measures absorption of light by organic molecules. Initially, a calibration model wa...

  11. [Application of near infrared spectroscopy technique to nondestructive measurement of vegetable quality].

    PubMed

    Xie, Li-Juan; Ying, Yi-Bin; Yu, Hai-Yan; Fu, Xia-Ping

    2007-06-01

    Nondestructive detection techniques of vegetable include electrical properties, optical reflectance and transmission, sonic vibration, nuclear magnetic resonance (NMR), machine vision, aromatic volatile emission, vibration characteristics and others. The most widely employed and successful technique is to use its optical property. Near infrared spectroscopy technique is extremely fast, highly efficient, cheap to implement, of good recurrence and no sample preparation, and is a rapid and non-destructive modern measuring technique that has been widely used in many fields. In the present paper, the application of near infrared spectroscopy technique to nondestructive measurement of vegetable quality was briefly introduced. Some considerable aspects existing in the application were also discussed, and it is pointed out that because of vegetable's diversity and rot-proneness, automation analysis machine should be developed to improve the speed of quality detection, and cooperating with several other nondestructive techniques, such as NMR and machine vision, is the research trend. PMID:17763775

  12. Gastric cancer differentiation using Fourier transform near-infrared spectroscopy with unsupervised pattern recognition

    NASA Astrophysics Data System (ADS)

    Yi, Wei-song; Cui, Dian-sheng; Li, Zhi; Wu, Lan-lan; Shen, Ai-guo; Hu, Ji-ming

    2013-01-01

    The manuscript has investigated the application of near-infrared (NIR) spectroscopy for differentiation gastric cancer. The 90 spectra from cancerous and normal tissues were collected from a total of 30 surgical specimens using Fourier transform near-infrared spectroscopy (FT-NIR) equipped with a fiber-optic probe. Major spectral differences were observed in the CH-stretching second overtone (9000-7000 cm-1), CH-stretching first overtone (6000-5200 cm-1), and CH-stretching combination (4500-4000 cm-1) regions. By use of unsupervised pattern recognition, such as principal component analysis (PCA) and cluster analysis (CA), all spectra were classified into cancerous and normal tissue groups with accuracy up to 81.1%. The sensitivity and specificity was 100% and 68.2%, respectively. These present results indicate that CH-stretching first, combination band and second overtone regions can serve as diagnostic markers for gastric cancer.

  13. Reduced near-infrared absorption using ultra-thin lossy metals in Fabry-Perot cavities

    PubMed Central

    Kocer, Hasan; Butun, Serkan; Li, Zhongyang; Aydin, Koray

    2015-01-01

    We show that a triple-layer metal-insulator-metal (MIM) structure has spectrally selective IR absorption, while an ultra-thin metal film has non-selective absorption in the near infrared wavelengths. Both sub-wavelength scale structures were implemented with an ultra-thin 6 nm Cr top layer. MIM structure was demonstrated to have near perfect absorption at λ = 1.2 μm and suppressed absorption at λ = 1.8 μm in which experimental and simulated absorptions of the thin Cr film are even higher than the MIM. Occurrence of absorption peaks and dips in the MIM were explained with the electric field intensity localization as functions of both the wavelength and the position. It has been shown that the power absorption in the lossy material is a strong function of the electric field intensity i.e. the more the electric field intensity, the more the absorption and vice versa. Therefore, it is possible to engineer IR emissive properties of these ultra-thin nanocavities by controlling the electric field localization with proper designs. PMID:25640732

  14. Reduced near-infrared absorption using ultra-thin lossy metals in Fabry-Perot cavities.

    PubMed

    Kocer, Hasan; Butun, Serkan; Li, Zhongyang; Aydin, Koray

    2015-01-01

    We show that a triple-layer metal-insulator-metal (MIM) structure has spectrally selective IR absorption, while an ultra-thin metal film has non-selective absorption in the near infrared wavelengths. Both sub-wavelength scale structures were implemented with an ultra-thin 6 nm Cr top layer. MIM structure was demonstrated to have near perfect absorption at λ = 1.2 μm and suppressed absorption at λ = 1.8 μm in which experimental and simulated absorptions of the thin Cr film are even higher than the MIM. Occurrence of absorption peaks and dips in the MIM were explained with the electric field intensity localization as functions of both the wavelength and the position. It has been shown that the power absorption in the lossy material is a strong function of the electric field intensity i.e. the more the electric field intensity, the more the absorption and vice versa. Therefore, it is possible to engineer IR emissive properties of these ultra-thin nanocavities by controlling the electric field localization with proper designs. PMID:25640732

  15. Multivariate Calibration Models for Sorghum Composition using Near-Infrared Spectroscopy

    SciTech Connect

    Wolfrum, E.; Payne, C.; Stefaniak, T.; Rooney, W.; Dighe, N.; Bean, B.; Dahlberg, J.

    2013-03-01

    NREL developed calibration models based on near-infrared (NIR) spectroscopy coupled with multivariate statistics to predict compositional properties relevant to cellulosic biofuels production for a variety of sorghum cultivars. A robust calibration population was developed in an iterative fashion. The quality of models developed using the same sample geometry on two different types of NIR spectrometers and two different sample geometries on the same spectrometer did not vary greatly.

  16. Near-infrared Spectroscopy of Brown Dwarf and Planetary-Mass Members in Upper Scorpius

    NASA Astrophysics Data System (ADS)

    Lodieu, Nicolas

    2016-01-01

    In these proceedings, I present new VLT/X-shooter near-infrared spectroscopy of brown dwarf and planetary-mass candidates with masses below 30 Jupiter masses identified in a deep VISTA ZYJ survey of 13.5 square degrees in the Upper Scorpius (USco) association. These spectra represent new benchmarks at 5-10 Myr to compare with known and future discoveries of members in nearby moving groups and other young regions.

  17. Authentication of cow feeding and geographic origin on milk using visible and near-infrared spectroscopy.

    PubMed

    Coppa, M; Martin, B; Agabriel, C; Chassaing, C; Sibra, C; Constant, I; Graulet, B; Andueza, D

    2012-10-01

    The ability of near-infrared spectroscopy to trace cow feeding systems and farming altitude was tested on 486 bulk milk samples from France and northwestern Italy. Milks were grouped into feeding systems according to the main forage in the diet. Partial least square discriminant analysis correctly classified 95.5, 91.5, and 93.3% of pasture versus maize silage, hay, and fermented herbage feeding systems, respectively. Discrimination was slightly less successful when diets with large proportions of the nondominant forage were included in each group. Near-infrared spectroscopy correctly discriminated no-pasture from pasture milk, even with only 30% of pasture in the diet (5.4% cross-validation error), and the error stabilized when pasture exceeded 70% (2.5% error). Near-infrared spectroscopy did not reliably trace milk geographic origin when the feeding system effect was isolated from the altitude effect. These findings may be usefully exploited for the authentication of dairy products. PMID:22901470

  18. A novel objective sour taste evaluation method based on near-infrared spectroscopy.

    PubMed

    Hoshi, Ayaka; Aoki, Soichiro; Kouno, Emi; Ogasawara, Masashi; Onaka, Takashi; Miura, Yutaka; Mamiya, Kanji

    2014-05-01

    One of the most important themes in the development of foods and drinks is the accurate evaluation of taste properties. In general, a sensory evaluation system is frequently used for evaluating food and drink. This method, which is dependent on human senses, is highly sensitive but is influenced by the eating experience and food palatability of individuals, leading to subjective results. Therefore, a more effective method for objectively estimating taste properties is required. Here we show that salivary hemodynamic signals, as measured by near-infrared spectroscopy, are a useful objective indicator for evaluating sour taste stimulus. In addition, the hemodynamic responses of the parotid gland are closely correlated to the salivary secretion volume of the parotid gland in response to basic taste stimuli and respond to stimuli independently of the hedonic aspect. Moreover, we examined the hemodynamic responses to complex taste stimuli in food-based solutions and demonstrated for the first time that the complicated phenomenon of the "masking effect," which decreases taste intensity despite the additional taste components, can be successfully detected by near-infrared spectroscopy. In summary, this study is the first to demonstrate near-infrared spectroscopy as a novel tool for objectively evaluating complex sour taste properties in foods and drinks. PMID:24474216

  19. Phosphorescence, near-infrared absorption and nonlinear optical property of a new chiral organic crystal

    NASA Astrophysics Data System (ADS)

    Zhang, Bei; Zhao, Yu-Mei; Yong, Guo-Ping

    2014-02-01

    A new enantiomerically pure compound was synthesized by the single step reduced reaction from 2-(imidazo[1,2-a]pyridin-2-yl)-2-oxo-N-(pyridin-2-yl)acetamide via chiral induction with D-tartaric acid in good yield. Single crystal data confirm this compound crystallizes in chiral space group P21. Transmission spectrum reveals that the crystal has low UV cut-off of 372 nm and has a good transmittance in the entire visible and near-infrared (NIR)region to 1100 nm, indicating its optical application. Kurtz powder test shows a good second harmonic generation (SHG) which also demonstrates its chiral structure. Moreover, this material exhibits blue phosphorescence with quantum yield of 3.6% and unusually NIR absorption between 1500 nm and 2500 nm. Therefore, this new chiral crystal is a promising multifunctional material for the blue phosphorescence, NIR absorption and nonlinear optical (NLO) applications.

  20. Near-infrared absorption properties of oxygen-rich stardust analogs. The influence of coloring metal ions

    NASA Astrophysics Data System (ADS)

    Zeidler, Simon; Posch, Thomas; Mutschke, Harald; Richter, Hannes; Wehrhan, Ortrud

    2011-02-01

    Context. Several astrophysically relevant solid oxides and silicates have extremely small opacities in the visual and near-infrared in their pure forms. Datasets for the opacities and for the imaginary part k of their complex indices of refraction are hardly available in these wavelength ranges. Aims: We aimed at determining k for spinel, rutile, anatase, and olivine, especially in the near-infrared region. Our measurements were made with impurity-containing, natural, and synthetic stardust analogs. Methods: Two experimental methods were used: preparing small sections of natural minerals and synthesizing melt droplets under the electric arc furnace. In both cases, the aborption properties of the samples were measured by transmission spectroscopy. Results: For spinel (MgAl2O4), anatase, rutile (both TiO2), and olivine ((Mg,Fe)2SiO4), the optical constants have been extended to the visual and near-infrared. We highlight that the individual values of k(λ) and the absorption cross section Qabs(λ) depend strongly on the content in transition metals like iron. Based on our measurements, we infer that k values below 10-5 are very rare in natural minerals including stardust grains, if they occur at all. Conclusions: Data for k and Qabs(λ) are important for various physical properties of stardust grains such as temperature and radiation pressure. With increasing Qabs(λ) due to impurities, the equilibrium temperature of small grains in circumstellar shells increases as well. We discuss why and to what extent this is the case.

  1. Identification of anisodamine tablets by Raman and near-infrared spectroscopy with chemometrics

    NASA Astrophysics Data System (ADS)

    Li, Lian; Zang, Hengchang; Li, Jun; Chen, Dejun; Li, Tao; Wang, Fengshan

    2014-06-01

    Vibrational spectroscopy including Raman and near-infrared (NIR) spectroscopy has become an attractive tool for pharmaceutical analysis. In this study, effective calibration models for the identification of anisodamine tablet and its counterfeit and the distinguishment of manufacturing plants, based on Raman and NIR spectroscopy, were built, respectively. Anisodamine counterfeit tablets were identified by Raman spectroscopy with correlation coefficient method, and the results showed that the predictive accuracy was 100%. The genuine anisodamine tablets from 5 different manufacturing plants were distinguished by NIR spectroscopy using partial least squares discriminant analysis (PLS-DA) models based on interval principal component analysis (iPCA) method. And the results showed the recognition rate and rejection rate were 100% respectively. In conclusion, Raman spectroscopy and NIR spectroscopy combined with chemometrics are feasible and potential tools for rapid pharmaceutical tablet discrimination.

  2. SiC absorption of near-infrared laser radiation at high temperatures

    NASA Astrophysics Data System (ADS)

    Adelmann, B.; Hellmann, R.

    2016-07-01

    We report on a theoretical and experimental investigation of the temperature-dependent optical absorption of nitrogen-doped 4H-SiC for a temperature range between room temperature and the decomposition point. The theoretical model is based on free carrier absorption including the temperature dependence of the electron mobility. With respect to laser material processing of silicon carbide, the analysis focusses on a near-infrared wavelength range. At room temperature, the calculated absorption is in excellent agreement to transmission and reflection measurements. For the experimental study of the absorption at higher temperatures induced by intense 1070-nm laser irradiation, a two-color pyrometer is employed with the thermal emission of the laser interaction zone being collected coaxial to the impinging laser. Exemplarily, the simulated temperature-dependent absorption is used to determine the heating of a 0.4-mm-thick 4H-SiC specimen during laser irradiation and compared to the experimentally determined temperature. In an initial time domain of the irradiation with an attained temperature below 1350 K, the simulated and measured temperatures are in good agreement. Above 1350 K, however, the measured temperature reveals a sharp and fast increase up to 2100 K which is not predicted by the model. This discrepancy is attributed to a strong additional absorption mechanism caused by carbonization at the surface which is confirmed by EDX analysis.

  3. [Detection of reducing sugar content of potato granules based on wavelet compression by near infrared spectroscopy].

    PubMed

    Dong, Xiao-Ling; Sun, Xu-Dong

    2013-12-01

    The feasibility was explored in determination of reducing sugar content of potato granules based on wavelet compression algorithm combined with near-infrared spectroscopy. The spectra of 250 potato granules samples were recorded by Fourier transform near-infrared spectrometer in the range of 4000- 10000 cm-1. The three parameters of vanishing moments, wavelet coefficients and principal component factor were optimized. The optimization results of three parameters were 10, 100 and 20, respectively. The original spectra of 1501 spectral variables were transfered to 100 wavelet coefficients using db wavelet function. The partial least squares (PLS) calibration models were developed by 1501 spectral variables and 100 wavelet coefficients. Sixty two unknown samples of prediction set were applied to evaluate the performance of PLS models. By comparison, the optimal result was obtained by wavelet compression combined with PLS calibration model. The correlation coefficient of prediction and root mean square error of prediction were 0.98 and 0.181%, respectively. Experimental results show that the dimensions of spectral data were reduced, scarcely losing effective information by wavelet compression algorithm combined with near-infrared spectroscopy technology in determination of reducing sugar in potato granules. The PLS model is simplified, and the predictive ability is improved. PMID:24611373

  4. Broadband Epsilon-Near-Zero Perfect Absorption in the Near-Infrared

    PubMed Central

    Yoon, Junho; Zhou, Ming; Badsha, Md. Alamgir; Kim, Tae Young; Jun, Young Chul; Hwangbo, Chang Kwon

    2015-01-01

    Perfect absorption (PA) of incident light is important for both fundamental light-matter interaction studies and practical device applications. PA studies so far have mainly used resonant nanostructures that require delicate structural patterning. Here, we realize tunable and broadband PA in the near-infrared region using relatively simple thin film coatings. We adjust the growth condition of an ITO film and control its epsilon-near-zero (ENZ) wavelength. We show that this results in highly tunable PA in the telecommunication window. Then, using an ITO multilayer of different ENZ wavelengths, we demonstrate broadband PA that covers a wide range of near-infrared wavelengths. The use of ENZ coatings makes PA adjustable during the film growth and does not require any structural patterning afterward. It also facilitates the chip-scale integration of perfect absorbers with other device components. Broadband PA relaxes the single wavelength condition in previous PA studies, and thus it is suitable for many practical device applications, including sensors, photodetectors, and energy harvesting devices. PMID:26239808

  5. Near-infrared spectroscopy (NIRS) as a diagnostic tool in patients with suspected stroke or traumatic brain injury

    NASA Astrophysics Data System (ADS)

    Goldberg, Sonja; Lott, Carsten; Ostermeyer, M.; Hennes, Hans-Juergen

    2001-10-01

    Near-Infrared Spectroscopy (NIRS) as a diagnostic tool in patients with suspected stroke or brain injury S. Goldberg, C. Lott, M. Ostermeyer, H.-J. Hennes Absorption of Near-Infrared (NIR) light in the brain is mainly caused by hemoglobin. Superficial intracranial hematoma with a higher concentration of hemoglobin causes a higher absorption in NIRS. The existence of hemorrhage can be demonstrated by the difference of optical density, comparing identical measuring points at both hemispheres of the brain: absorption of NIR light is greater at the side of the hemorrhage, causing less reflection in NIRS. In a prospective, blinded study, 100 patients who were scheduled for CCT-scan for brain injury or symptoms of stroke have been measured by NIRS. The measurement results were proved by the CCT-diagnosis. A sensitivity of the NIR measurement of 65% and a specificity of 87% was achieved including all patients with any pathology, whereas the subgroup of 58 patients with suspected superficial hematoma and without other pathology showed pathologic findings by NIRS in all of 16 patients indicating superficial bleeding by CCT, pathology could be excluded by NIRS and CCT in 41 patients, one false positive and no false negative result. The results (sensitivity 98%, specificity 100%) support the hypothesis that NIRS is a reliable device for the detection of superficial intracranial hematoma.

  6. Analysis of total oil and fatty acids composition by near infrared reflectance spectroscopy in edible nuts

    NASA Astrophysics Data System (ADS)

    Kandala, Chari V.; Sundaram, Jaya

    2014-10-01

    Near Infrared (NIR) Reflectance spectroscopy has established itself as an important tool in quantifying water and oil present in various food materials. It is rapid and nondestructive, easier to use, and does not require processing the samples with corrosive chemicals that would render them non-edible. Earlier, the samples had to be ground into powder form before making any measurements. With the development of new soft ware packages, NIR techniques could now be used in the analysis of intact grain and nuts. While most of the commercial instruments presently available work well with small grain size materials such as wheat and corn, the method present here is suitable for large kernel size products such as shelled or in-shell peanuts. Absorbance spectra were collected from 400 nm to 2500 nm using a NIR instrument. Average values of total oil contents (TOC) of peanut samples were determined by standard extraction methods, and fatty acids were determined using gas chromatography. Partial least square (PLS) analysis was performed on the calibration set of absorption spectra, and models were developed for prediction of total oil and fatty acids. The best model was selected based on the coefficient of determination (R2), Standard error of prediction (SEP) and residual percent deviation (RPD) values. Peanut samples analyzed showed RPD values greater than 5.0 for both absorbance and reflectance models and thus could be used for quality control and analysis. Ability to rapidly and nondestructively measure the TOC, and analyze the fatty acid composition, will be immensely useful in peanut varietal improvement as well as in the grading process of grain and nuts.

  7. Stability test for amorphous materials in humidity controlled 96-well plates by near-infrared spectroscopy.

    PubMed

    Otsuka, Makoto; Tanabe, Hideaki

    2012-03-01

    The purpose of this research is to apply near infrared spectrometry (NIR) with chemoinformetrics to predict the change of crystalline properties of indomethacin (IMC) amorphous under various levels of relative humidity storage conditions. Stability test for amorphous and meta-stable polymorphic forms was performed in humidity controlled the modified 96-well quartz plates containing various kinds of saturated salt solutions (0-100% of relative humidity (RH)) by NIR spectroscopy. Amorphous form was obtained melt product to pour into liquid nitrogen and after then ground. Samples were stored at 25°C in the 6-well plates at various levels of RH. The spectra of the powder samples were measured by the reflectance FT-NIR spectrometer. The second derivative spectra of form α showed specific absorption peaks at 4980, 6036, 7296 and 8616 cm-1 and that of form γ showed those at 5020, 5028, 7344, 7428 and 8436 cm-1. After storage at less than 50% RH, the peak intensities at 5020, 5028, 7344, 7428 and 8436 cm-1 of the amorphous solid increased with increasing of storage time. However, the peak intensity at 4980, 6036 and 7296 cm-1 increased at more than 50% RH Please check and confirm the edit. The results suggested that at lower humidity, the IMC amorphous solid transformed into form γ, but it transformed into form α at more than high humidity. It is possible that crystalline stability of the pharmaceutical preparations could be predicted by using humidity controlled 96-well plates and reflectance NIR-chemoinformetric methods. PMID:21942281

  8. Near-infrared spectroscopy of the super star cluster in NGC 1705

    NASA Astrophysics Data System (ADS)

    Martins, F.; Förster Schreiber, N. M.; Eisenhauer, F.; Lutz, D.

    2012-11-01

    Aims: We study the near-infrared properties of the super star cluster NGC 1750-1 to constrain its spatial extent, its stellar population, and its age. Methods: We used adaptive-optics assisted integral field spectroscopy with SINFONI on the Very Large Telescope. We estimated the spatial extent of the cluster and extracted its K-band spectrum from which we constrained the age of the dominant stellar population. Results: Our observations have an angular resolution of about 0.11'', providing an upper limit on the cluster radius of 2.85 ± 0.50 pc depending on the assumed distance. The K-band spectrum is dominated by strong CO absorption bandheads typical of red supergiants. Its spectral type is equivalent to a K4-5I star. Using evolutionary tracks from the Geneva and Utrecht groups, we determine an age of 12 ± 6 Myr. The large uncertainty is rooted in the large difference between the Geneva and Utrecht tracks in the red supergiants regime. The absence of ionized gas lines in the K-band spectrum is consistent with the absence of O and/or Wolf-Rayet stars in the cluster, as expected for the estimated age. Based on observations collected at the ESO/VLT under program 384.D-0301(A).The FITS file of the reduced cluster spectrum is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/547/A17

  9. Tracking the dehydration process of raw honey by synchronous two-dimensional near infrared correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Chen, Guiyun; Sun, Xin; Huang, Yuping; Chen, Kunjie

    2014-11-01

    Though much attention is paid to honey quality assessment, few reports on characteristic of manually dehydrated honey have been found. The aim of this investigation is to track the dehydration process of raw honey using synchronous two-dimensional (2D) near infrared correlation spectroscopy. To minimize the impact of dehydration to honey quality, seventy-two honey samples from six different dehydration stages were obtained using drum wind drying method with temperature controlled at 40 °C. Their dynamic short-wave NIR spectra from 600 to 1100 nm were collected in the transmission mode from 10 to 50 °C with an increment of 5 °C and were analyzed using synchronous two-dimensional correlation method. Short-wave NIR spectral data has been exploited less than other NIR region for its weaker signal especially for water absorption's interference with useful information. The investigation enlarged the signal at this band using synchronous 2D correlation analysis, revealing the fingerprinting feature of rape honey and chaste honey during the artificial dehydration process. The results have shown that, with the help of 2D correlation analysis, this band can detect the variation of the second overtone of O-H and N-H groups vibration upon their H-bonds forming or collapsing resulted from the interactions between water and solute. The results have also shown that 2D-NIRS method is able to convert the tiny changes in honey constituents into the detectable fingerprinting difference, which provides a new method for assessing honey quality.

  10. Estimation of Concentration and Bonding Environment of Water Dissolved in Common Solvents Using Near Infrared Absorptivity

    PubMed Central

    Dickens, Brian; Dickens, Sabine H.

    1999-01-01

    Integrated near infrared (NIR) absorbance has been used to determine the absorptivity of the υ2 + υ3 combination band of the asymmetric stretch (υ2) and the bending vibration (υ3) for water in several organic solvents. Absorptivity measured in this way is essentially constant across the absorption envelope and is found to be 336 L mol−1 cm−1 with a standard deviation of 4 L mol−1 cm−1 as estimated from a least squares fit of a straight line to data from water concentrations between 0.01 mol/L and 0.06 mol/L. Absorptivity measured from the peak maximum of the υ2 + υ3 combination band of water varies with the type of hydrogen bonding of the water molecule because the shape of the NIR absorption envelope changes with the hydrogen bonding. Because the integrated NIR absorptivity of the υ2 + υ3 combination band of water is essentially constant across the absorption envelope, the NIR absorption envelope reflects the distribution of hydrogen bonding of the water. The shape and location of the absorption envelope appear to be governed mostly by the number of hydrogen bonds from the water molecules to easily polarized atoms. Water that is a donor in hydrogen bonds to atoms which are not easily polarized (such as the oxygen of a typical carbonyl group) absorbs near 5240 cm−1 to 5260 cm−1. Water that donates one hydrogen bond to an easily polarized atom (such as a water molecule oxygen) absorbs near 5130 cm−1 to 5175 cm−1, and water that donates two hydrogen bonds to easily polarized atoms is estimated to absorb near 5000 cm−1 to 5020 cm−1. Water donating two hydrogen bonds to other water molecules may be said to be in a water-like environment. In no case does a small amount of water absorbed in a host material appear to have a water-like environment.

  11. Electrochromism in the near-infrared absorption spectra of bridged ruthenium mixed-valence complexes

    SciTech Connect

    Oh, D.H.; Boxer, S.G. )

    1990-10-24

    Many experimental and theoretical approaches have been developed to characterize the chemical and physical properties of mixed-valence complexes. These molecules may possess metals in differing oxidation states which participate in intervalence charge-transfer transitions. In principle, these transitions should be strongly affected by an external electric field. Such electrochromism can provide a direct and sensitive approach to investigating the electronic properties of molecules. The authors report the first measurements of the effects of an externally applied electric field on the near-infrared absorption spectra of ((NH{sub 3}){sub 5}Ru){sub 2}L{sup 5+} (L = pyrazine or 4,4{prime}-bipyridine). Significant differences are observed between the two complexes, illustrating the range of electronic interactions between the metal centers.

  12. A Near-Infrared Spectrometer to Measure Zodiacal Light Absorption Spectrum

    NASA Technical Reports Server (NTRS)

    Kutyrev, A. S.; Arendt, R.; Dwek, E.; Kimble, R.; Moseley, S. H.; Rapchun, D.; Silverberg, R. F.

    2010-01-01

    We have developed a high throughput infrared spectrometer for zodiacal light fraunhofer lines measurements. The instrument is based on a cryogenic dual silicon Fabry-Perot etalon which is designed to achieve high signal to noise Fraunhofer line profile measurements. Very large aperture silicon Fabry-Perot etalons and fast camera optics make these measurements possible. The results of the absorption line profile measurements will provide a model free measure of the zodiacal Light intensity in the near infrared. The knowledge of the zodiacal light brightness is crucial for accurate subtraction of zodiacal light foreground for accurate measure of the extragalactic background light after the subtraction of zodiacal light foreground. We present the final design of the instrument and the first results of its performance.

  13. Comparison of Diffuse Reflectance Fourier Transform Mid-Infrared and Near-Infrared Spectroscopy with Grating-Based Near-Infrared for the Determination of Fatty Acids in Forages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diffuse reflectance Fourier transform mid-infrared (FTMIR) and near infrared spectroscopy (FTNIR) were compared to scanning monochromator-grating-based near infrared spectroscopy (SMNIR), for their ability to quantify fatty acids (FA) in forages. Thirteen different forage cultivars belonging to 11 d...

  14. [Identification of Animal Whole Blood Based on Near Infrared Transmission Spectroscopy].

    PubMed

    Wan, Xiong; Wang, Jian; Liu, Peng-xi; Zhang, Ting-ting

    2016-01-01

    The inspection and classification for blood products are important but complicated in import-export ports or inspection and quarantine departments. For the inspection of whole blood products, open sampling can cause pollution and virulence factors in bloods samples may even endanger inspectors. Thus non-contact classification and identification methods for whole bloods of animals are needed. Spectroscopic techniques adopted in the flowcytometry need sampling blood cells during the detection; therefore they can not meet the demand of non-contact identification and classification for whole bloods of animals. Infrared absorption spectroscopy is a technique that can be used to analyze the molecular structure and chemical bonds of detected samples under the condition of non-contact. To find a feasible spectroscopic approach of non-contact detection for the species variation in whole blood samples, a near infrared transmitted spectra (NITS, 4 497.669 - 7 506.4 cm(-1)) experiment of whole blood samples of three common animals including chickens, dogs and cats has been conducted. During the experiment, the spectroscopic resolution is 5 cm(-1), and each spectrogram is an average of 5 measured spectral data. Experimental results show that all samples have a sharp absorption peak between 5 184 and 5 215 cm(-1), and a gentle absorption peak near 7 000 cm(-1). Besides, the NITS curves of different samples of same animals are similar, and only have slight differences in the whole transmittance. A correlation coefficient (CC) is induced to distinguish the differences of the three animals' whole bloods in NITS curves, and the computed CCs between NITS curves of different samples of the same animals, are greater than 0.99, whereas CCs between NITS curves of the whole bloods of different animals are from 0.509 48 to 0.916 13. Among which CCs between NITS curves of the whole bloods of chickens and cats are from 0.857 23 to 0.912 44, CCs between NITS curves of the whole bloods of

  15. Origin of Near-Infrared Absorption for Azulene-Containing Conjugated Polymers upon Protonation or Oxidation.

    PubMed

    Tang, Tao; Lin, Tingting; Wang, FuKe; He, Chaobin

    2015-06-25

    A series of azulene-containing conjugated polymers were studied to elucidate their tunable absorption properties in near-infrared (NIR) regions (i.e., 1.2-2.5 μm) upon protonation/oxidation. Density function theory (DFT) revealed that protonation-induced intramolecular charge transfer (ICT) in the polymer backbone lead to strong NIR absorption. Distinct spectral change was observed when tiny amount of peroxide was added to the protonated polymer in trifluoroacetic acid/chloroform solution. Electron paramagnetic resonance (EPR) study confirmed the presence of radical cation, which results in the occurrence of newly formed absorption band after the addition of peroxide. The spectro-electrochemical results and DFT study indicate that polarons and polaron pairs were formed during p-doping process, and both the chemical oxidation and electrochemical oxidation could be facilitated by TFA protonation. This represents the first reported mechanisms of NIR absorption under various protonation/oxidation conditions in a single polymer system. PMID:25993246

  16. [Drug discrimination by near infrared spectroscopy based on summation wavelet extreme learning machine].

    PubMed

    Liu, Zhen-Bing; Jiang, Shu-Jie; Yang, Hui-Hua; Zhang, Xue-Bo

    2014-10-01

    As an effective technique to identify counterfeit drugs, Near Infrared Spectroscopy has been successfully used in the drug management of grass-roots units, with classifier modeling of Pattern Recognition. Due to a major disadvantage of the characteristic overlap and complexity, the wide bandwidth and the weak absorption of the Spectroscopy signals, it seems difficult to give a satisfactory solutions for the modeling problem. To address those problems, in the present paper, a summation wavelet extreme learning machine algorithm (SWELM(CS)) combined with Cuckoo research was adopted for drug discrimination by NIRS. Specifically, Extreme Learning Machine (ELM) was selected as the classifier model because of its properties of fast learning and insensitivity, to improve the accuracy and generalization performances of the classifier model; An inverse hyperbolic sine and a Morlet-wavelet are used as dual activation functions to improve convergence speed, and a combination of activation functions makes the network more adequate to deal with dynamic systems; Due to ELM' s weights and hidden layer threshold generated randomly, it leads to network instability, so Cuckoo Search was adapted to optimize model parameters; SWELM(CS) improves stability of the classifier model. Besides, SWELM(CS) is based on the ELM algorithm for fast learning and insensitivity; the dual activation functions and proper choice of activation functions enhances the capability of the network to face low and high frequency signals simultaneously; it has high stability of classification by Cuckoo Research. This compact structure of the dual activation functions constitutes a kernel framework by extracting signal features and signal simultaneously, which can be generalized to other machine learning fields to obtain a good accuracy and generalization performances. Drug samples of near in- frared spectroscopy produced by Xian-Janssen Pharmaceutical Ltd were adopted as the main objects in this paper

  17. Water vapour foreign-continuum absorption in near-infrared windows from laboratory measurements.

    PubMed

    Ptashnik, Igor V; McPheat, Robert A; Shine, Keith P; Smith, Kevin M; Williams, R Gary

    2012-06-13

    For a long time, it has been believed that atmospheric absorption of radiation within wavelength regions of relatively high infrared transmittance (so-called 'windows') was dominated by the water vapour self-continuum, that is, spectrally smooth absorption caused by H(2)O--H(2)O pair interaction. Absorption due to the foreign continuum (i.e. caused mostly by H(2)O--N(2) bimolecular absorption in the Earth's atmosphere) was considered to be negligible in the windows. We report new retrievals of the water vapour foreign continuum from high-resolution laboratory measurements at temperatures between 350 and 430 K in four near-infrared windows between 1.1 and 5 μm (9000-2000 cm(-1)). Our results indicate that the foreign continuum in these windows has a very weak temperature dependence and is typically between one and two orders of magnitude stronger than that given in representations of the continuum currently used in many climate and weather prediction models. This indicates that absorption owing to the foreign continuum may be comparable to the self-continuum under atmospheric conditions in the investigated windows. The calculated global-average clear-sky atmospheric absorption of solar radiation is increased by approximately 0.46 W m(-2) (or 0.6% of the total clear-sky absorption) by using these new measurements when compared with calculations applying the widely used MTCKD (Mlawer-Tobin-Clough-Kneizys-Davies) foreign-continuum model. PMID:22547232

  18. Monitoring of cerebral hemodynamics during open-heart surgery in children using near-infrared intensity-modulated spectroscopy

    NASA Astrophysics Data System (ADS)

    Kohl-Bareis, Matthias; Watson, Russell W.; Chow, Gabriel; Roberts, Idris; Delpy, David T.; Cope, Mark

    1997-08-01

    Neurological impairments following cardiopulmonary bypass (CPB) during open heart surgery can result from microembolism and ischaemia. Here we present preliminary results from monitoring cerebral hemodynamics during CPB with near infrared intensity modulated spectroscopy. In particular, the study had two main objectives: (1) to monitor the oxy- and deoxy hemoglobin concentrations and their changes during the CPB surgery and (2) to monitor the transport scattering coefficient ((mu) s') of the brain especially during cooling and rewarming. A new method for the calculation of absolute absorption coefficients ((mu) a) was also tested. This method is based upon the monitoring of attenuation and phase changes that are induced by variations in absorption. These variations can be generated either by alterations in the tissue oxygenation or by injecting a dye (indocyanine green) into the CPB circuit. Absolute oxy- and deoxyhemoglobin concentrations and their changes during the CPB were calculated. The preliminary results suggest that cooling of the brain does not significantly alter (mu) s'.

  19. Capsaicinoids content prediction model development for Korean red-pepper powder using a visible and near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Lim, Jongguk; Mo, Changyeun; Noh, Sang Ha; Kang, Sukwon; Lee, Kangjin; Kim, Moon S.

    2012-05-01

    A nondestructive, real-time pungency measuring system with visible and near-infrared spectroscopy has been recently developed to measure capsaicinoids content in Korean red-pepper powder. One hundred twenty-five red-pepper powder samples produced from 11 regions in Republic of Korea were used for this investigation. The visible and near-infrared absorption spectra in the range from 450 to 950 nm were acquired and used for the development of prediction models of capsaicinoids contents in red-pepper powders without any chemical pretreatment to the samples. Partial Least Squares Regression (PLSR) models were developed to predict the regional capsaicinoids contents using the acquired absorption spectra. The chemical analysis of the total capsaicinoids (capsaicin and dihydrocapsaicin) was performed by a high performance liquid chromatographic (HPLC) method. The determination coefficient of validation (RV 2) and the standard error of prediction (SEP) for the capsaicinoids content prediction model, for a representative region in this study, were 0.9585 and +/-10.147 mg/100g, respectively.

  20. Food Safety Evaluation Based on Near Infrared Spectroscopy and Imaging: A Review.

    PubMed

    Fu, Xiaping; Ying, Yibin

    2016-08-17

    In recent years, due to the increasing consciousness of food safety and human health, much progress has been made in developing rapid and nondestructive techniques for the evaluation of food hazards, food authentication, and traceability. Near infrared (NIR) spectroscopy and imaging techniques have gained wide acceptance in many fields because of their advantages over other analytical techniques. Following a brief introduction of NIR spectroscopy and imaging basics, this review mainly focuses on recent NIR spectroscopy and imaging applications for food safety evaluation, including (1) chemical hazards detection; (2) microbiological hazards detection; (3) physical hazards detection; (4) new technology-induced food safety concerns; and (5) food traceability. The review shows NIR spectroscopy and imaging to be effective tools that will play indispensable roles for food safety evaluation. In addition, on-line/real-time applications of these techniques promise to be a huge growth field in the near future. PMID:24972267

  1. Near infrared cavity enhanced absorption spectra of atmospherically relevant ether-1, 4-Dioxane.

    PubMed

    Chandran, Satheesh; Varma, Ravi

    2016-01-15

    1, 4-Dioxane (DX) is a commonly found ether in industrially polluted atmosphere. The near infrared absorption spectra of this compound has been recorded in the region 5900-8230 cm(-1) with a resolution of 0.08 cm(-1) using a novel Fourier transform incoherent broadband cavity-enhanced absorption spectrometer (FT-IBBCEAS). All recorded spectra were found to contain regions that are only weakly perturbed. The possible combinations of fundamental modes and their overtone bands corresponding to selected regions in the measured spectra are tabulated. Two interesting spectral regions were identified as 5900-6400 cm(-1) and 8100-8230 cm(-1). No significant spectral interference due to presence of water vapor was observed suggesting the suitability of these spectral signatures for spectroscopic in situ detection of DX. The technique employed here is much more sensitive than standard Fourier transform spectrometer measurements on account of long effective path length achieved. Hence significant enhancement of weaker absorption lines above the noise level was observed as demonstrated by comparison with an available measurement from database. PMID:26474242

  2. Near infrared cavity enhanced absorption spectra of atmospherically relevant ether-1, 4-Dioxane

    NASA Astrophysics Data System (ADS)

    Chandran, Satheesh; Varma, Ravi

    2016-01-01

    1, 4-Dioxane (DX) is a commonly found ether in industrially polluted atmosphere. The near infrared absorption spectra of this compound has been recorded in the region 5900-8230 cm- 1 with a resolution of 0.08 cm- 1 using a novel Fourier transform incoherent broadband cavity-enhanced absorption spectrometer (FT-IBBCEAS). All recorded spectra were found to contain regions that are only weakly perturbed. The possible combinations of fundamental modes and their overtone bands corresponding to selected regions in the measured spectra are tabulated. Two interesting spectral regions were identified as 5900-6400 cm- 1 and 8100-8230 cm- 1. No significant spectral interference due to presence of water vapor was observed suggesting the suitability of these spectral signatures for spectroscopic in situ detection of DX. The technique employed here is much more sensitive than standard Fourier transform spectrometer measurements on account of long effective path length achieved. Hence significant enhancement of weaker absorption lines above the noise level was observed as demonstrated by comparison with an available measurement from database.

  3. Ultrafast near-infrared nonlinear absorption in a multiferroic single crystal of bismuth ferrite

    NASA Astrophysics Data System (ADS)

    Matsubara, Eiichi; Mochizuki, Takeshi; Nagai, Masaya; Ito, Toshimitsu; Ashida, Masaaki

    2015-09-01

    We studied the ultrafast third-order optical nonlinearity in a single crystal of multiferroic bismuth ferrite (BiFeO3) in the near-infrared range of 0.5-1.0 eV, where the material is fundamentally transparent, at room temperature. With pump pulses at 1.55 eV, which is off-resonant to the strong inter-band charge transfer (CT) transition, we observed instantaneous transient absorption with a pencil-like temporal profile originating from the two-photon CT transition from the oxygen 2p to the iron 3d levels. In contrast, under pumping with 3.10 eV photons, the pencil-like absorption change was not observed but decay profiles showed longer time constants. Although the two-photon absorption coefficient estimated to be 1.5 cm/GW is 10 (100) times smaller than that of two (one)-dimensional cuprates, it is larger than those of common semiconductors such as ZnSe at the optical communication wavelength.

  4. Application of spectral derivative data in visible and near-infrared spectroscopy

    PubMed Central

    Dehghani, Hamid; Leblond, Frederic; Pogue, Brian W; Chauchard, Fabien

    2011-01-01

    The use of the spectral derivative method in visible and near-infrared optical spectroscopy is presented, whereby instead of using discrete measurements around several wavelengths, the difference between nearest neighbouring spectral measurements is utilized. The proposed technique is shown to be insensitive to the unknown tissue and fibre contact coupling coefficients providing substantially increased accuracy as compared to more conventional techniques. The self-calibrating nature of the spectral derivative techniques increases its robustness for both clinical and industrial applications, as is demonstrated based on simulated results as well as experimental data. PMID:20505221

  5. Near-Infrared Spectroscopy in the Monitoring of Adult Traumatic Brain Injury: A Review

    PubMed Central

    Su, Zhangjie; Clancy, Michael T.; Lucas, Samuel J. E.; Dehghani, Hamid; Logan, Ann; Belli, Antonio

    2015-01-01

    Abstract Cerebral near-infrared spectroscopy (NIRS) has long represented an exciting prospect for the noninvasive monitoring of cerebral tissue oxygenation and perfusion in the context of traumatic brain injury (TBI), although uncertainty still exists regarding the reliability of this technology specifically within this field. We have undertaken a review of the existing literature relating to the application of NIRS within TBI. We discuss current “state-of-the-art” NIRS monitoring, provide a brief background of the technology, and discuss the evidence regarding the ability of NIRS to substitute for established invasive monitoring in TBI. PMID:25603012

  6. Analyzing the resting state functional connectivity in the human language system using near infrared spectroscopy

    PubMed Central

    Molavi, Behnam; May, Lillian; Gervain, Judit; Carreiras, Manuel; Werker, Janet F.; Dumont, Guy A.

    2014-01-01

    We have evaluated the use of phase synchronization to identify resting state functional connectivity (RSFC) in the language system in infants using functional near infrared spectroscopy (fNIRS). We used joint probability distribution of phase between fNIRS channels with a seed channel in the language area to estimate phase relations and to identify the language system network. Our results indicate the feasibility of this method in identifying the language system. The connectivity maps are consistent with anatomical cortical connections and are also comparable to those obtained from functional magnetic resonance imaging (fMRI) functional connectivity studies. The results also indicate left hemisphere lateralization of the language network. PMID:24523685

  7. Resting state connectivity patterns with near-infrared spectroscopy data of the whole head

    PubMed Central

    Novi, Sergio L.; Rodrigues, Renato B. M. L.; Mesquita, Rickson C.

    2016-01-01

    Resting state cerebral dynamics has been a useful approach to explore the brain’s functional organization. In this study, we employed graph theory to deeply investigate resting state functional connectivity (rs-FC) as measured by near-infrared spectroscopy (NIRS). Our results suggest that network parameters are very similar across time and subjects. We also identified the most frequent connections between brain regions and the main hubs that participate in the spontaneous activity of brain hemodynamics. Similar to previous findings, we verified that symmetrically located brain areas are highly connected. Overall, our results introduce new insights in NIRS-based functional connectivity at rest. PMID:27446687

  8. Noninvasive detection of intracerebral hemorrhage using near-infrared spectroscopy (NIRS)

    NASA Astrophysics Data System (ADS)

    Hennes, Hans-Juergen; Lott, Carsten; Windirsch, Michael; Hanley, Daniel F.; Boor, Stephan; Brambrink, Ansgar; Dick, Wolfgang

    1998-01-01

    Intracerebral Hemorrhage (IH) is an important cause of secondary brain injury in neurosurgical patients. Early identification and treatment improve neurologic outcome. We have tested Near Infrared Spectroscopy (NIRS) as an alternative noninvasive diagnostic tool compared to CT-Scans to detect IH. We prospectively studied 212 patients with neurologic symptoms associated with intracranial pathology before performing a CT-scan. NIRS signals indicated pathologies in 181 cases (sensitivity 0.96; specificity 0.29). In a subgroup of subdural hematomas NIRS detected 45 of 46 hematomas (sensitivity 0.96; specificity 0.79). Identification of intracerebral hemorrhage using NIRS has the potential to allow early treatment, thus possibly avoiding further injury.

  9. Noninvasive detection of intracerebral hemorrhage using near-infrared spectroscopy (NIRS)

    NASA Astrophysics Data System (ADS)

    Hennes, Hans J.; Lott, C.; Windirsch, Michael; Hanley, Daniel F.; Boor, Stephan; Brambrink, Ansgar; Dick, Wolfgang

    1997-12-01

    Intracerebral Hemorrhage (IH) is an important cause of secondary brain injury in neurosurgical patients. Early identification and treatment improve neurologic outcome. We have tested Near Infrared Spectroscopy (NIRS) as an alternative noninvasive diagnostic tool compared to CT-Scans to detect IH. We prospectively studied 212 patients with neurologic symptoms associated with intracranial pathology before performing a CT-scan. NIRS signals indicated pathologies in 181 cases (sensitivity 0.96; specificity 0.29). In a subgroup of subdural hematomas NIRS detected 45 of 46 hematomas (sensitivity 0.96; specificity 0.79). Identification of intracerebral hemorrhage using NIRS has the potential to allow early treatment, thus possibly avoiding further injury.

  10. Near-infrared surface-enhanced Raman spectroscopy: New developments and applications

    SciTech Connect

    Angel, S.M.; Myrick, M.L.

    1989-01-01

    The surface-enhanced Raman phenomenon was discovered in 1974 and analytical applications of it are only now being developed. Near-infrared surface-enhanced Raman spectroscopy was first reported in 1988, and the characteristics of the technique are still being determined. The purpose of this paper is to introduce the reader to the technique and to describe some of its characteristics. In addition, some of the applications being explored by the authors, including remote monitoring of groundwater contaminants and qualitative assays for drugs, are presented. 61 refs., 12 figs.

  11. Long open path Fourier transform spectroscopy measurements of greenhouse gases in the near infrared

    NASA Astrophysics Data System (ADS)

    Griffith, David; Pöhler, Denis; Schmidt, Stefan; Hammer, Samuel; Vardag, Sanam; Levin, Ingeborg; Platt, Ulrich

    2015-04-01

    Atmospheric composition measurements are an important tool to quantify local and regional emissions and sinks of greenhouse gases. But how representative are in situ measurements at one point in an inhomogeneous environment? Open path Fourier Transform Spectroscopy (FTS) measurements potentially offer spatial averaging and continuous measurements of several trace gases (including CO2, CH4, CO and N2O) simultaneously in the same airmass. Spatial averaging over kilometre scales is a better fit to the finest scale atmospheric models becoming available, and helps bridge the gap between models and in situ measurements. With what precision, accuracy and reliability can such measurements be made? Building on our pooled experience in ground-level open path Fourier transform spectroscopy and TCCON solar FTS in the infrared (Wollongong) and long path DOAS techniques in the UV-visible (Heidelberg), we set up a new type of open path measurement system across a 1.5 km one-way path in urban Heidelberg, Germany, using FTS in the near infrared. Direct open-atmosphere measurements of trace gases CO2, CH4, CO and N2O as well as O2 were retrieved from several absorption bands between 4000 and 8000 cm-1 (2.5 - 1.25 micron). At one end of the path an in situ FTIR analyser simultaneously collected well calibrated measurements of the same species for comparison with the open path-integrated measurements. The measurements ran continuously from June - November 2014. We introduce the open path FTS measurement system and present an analysis of the results, including assessment of precision, accuracy relative to co-incident in situ measurements, reliability, and avenues for further improvements and extensions. Short term precision of the open path measurement of CO2 was better than 1 ppm for 5 minute averages and thus sufficient for studies in urban and other non-background environments. Measurement bias relative to calibrated in situ measurements was stable across the measurement period. The

  12. Early detection of emerging street drugs by near infrared spectroscopy and chemometrics.

    PubMed

    Risoluti, R; Materazzi, S; Gregori, A; Ripani, L

    2016-06-01

    Near-infrared spectroscopy (NIRs) is spreading as the tool of choice for fast and non-destructive analysis and detection of different compounds in complex matrices. This paper investigated the feasibility of using near infrared (NIR) spectroscopy coupled to chemometrics calibration to detect new psychoactive substances in street samples. The capabilities of this approach in forensic chemistry were assessed in the determination of new molecules appeared in the illicit market and often claimed to contain "non-illegal" compounds, although exhibiting important psychoactive effects. The study focused on synthetic molecules belonging to the classes of synthetic cannabinoids and phenethylamines. The approach was validated comparing results with officials methods and has been successfully applied for "in site" determination of illicit drugs in confiscated real samples, in cooperation with the Scientific Investigation Department (Carabinieri-RIS) of Rome. The achieved results allow to consider NIR spectroscopy analysis followed by chemometrics as a fast, cost-effective and useful tool for the preliminary determination of new psychoactive substances in forensic science. PMID:27130135

  13. [Online determination of pH in fresh pork by visible/near-infrared spectroscopy].

    PubMed

    Liao, Yi-Tao; Fan, Yu-Xia; Wu, Xue-Qian; Cheng, Fang

    2010-03-01

    The present research was focused on determination of the pH value online by visible and near-infrared spectroscopy. In the part of data gathering, fresh pork longissimus dorsi was moving at the constant velocity of 0.25 m x s(-1) on the conveyor belt, and the visible and near-infrared diffuse reflectance spectrum (350-1 000 nm) was captured. In the part of data processing, band of 510-980 nm of the spectra was chosen to calibrate reflex distance, then to set up online detection model of pH value in fresh pork by partial least squares regression (PLSR). Kennard-stone algorithm was applied to divide the samples to the calibration set and validation set. The performances of several PLSR models employing various preprocessing methods including multiple scatter correction, derivative and both of them combined were compared. Further, the best performance model was optimized by interval PLSR to decrease the modeling variables of wavelength. The results indicated that the PLSR model based on preprocessing of multiple scatter correction (MSC) combined with first derivative gave the best performance with 0.905 of the correlation coefficient for validation set and 0.051 of the root of mean square errors for validation set. For the best PLSR model performance, the correlation coefficient of validation set increased to 0.926 and the root of mean square errors for validation set to 0.045 in the optimization interval PLSR model. However, only half of variables were used. The research demonstrates that using visible and near-infrared spectroscopy to determine fresh pork pH online is feasible. PMID:20496686

  14. Study and Development of near-Infrared Reflective and Absorptive Materials for Energy Saving Application

    NASA Astrophysics Data System (ADS)

    Cui, Yu Xing

    Near-Infrared (NIR) materials find applications in the field of energy saving. Both NIR reflective and absorptive materials can be used as energy saving materials with different working principles. The reflective materials can reflect the NIR light preventing it from being transmitted. Silver thin films are the best option as reflective films based on its reflectivity and cost. On the other hand, NIR absorptive materials can effectively convert the absorbed NIR light from sunlight to heat or electric energy. The first part of this research explored methods of preparing silver thin films that could be processed at low cost. The second part involved the design, synthesis and characterization of nickel coordination polymers as NIR absorptive materials. In part 1, different solution based methods of preparing silver thin films were studied. A silver nanoparticles solution was used to make thin film by a spray-pyrolysis process. Another method involved the surface activation with a fluoro-compound or silver nanoparticles followed by electroless silver plating on different substrates. Both methods could be processed at low cost. The obtained silver films showed NIR reflection of 50˜90% with transmission of 15-28% in the visible region. In part 2, two Nickel coordination polymers were explored. Tetraamino compounds were used as bridging ligands to increase the scope of electronic delocalization and metal-ligand orbital overlap which would reduce the energy gap to the NIR region. As a result, both polymers showed broad NIR absorption with maximum of 835 and 880 nm, respectively. In addition, the polymer showed NIR halochromism. This ground study pointed out both Ni coordination polymers as NIR absorptive materials with NIR halochromism.

  15. Dramatic enhancement of near-infrared intersubband absorption in c-plane AlInN/GaN superlattices

    NASA Astrophysics Data System (ADS)

    Shirazi-HD, M.; Turkmeneli, K.; Liu, S.; Dai, S.; Edmunds, C.; Shao, J.; Gardner, G.; Zakharov, D. N.; Manfra, M. J.; Malis, O.

    2016-03-01

    We report substantial improvement of near-infrared (2-2.6 μm) intersubband absorption in c-plane AlInN/GaN superlattices grown by molecular beam epitaxy. Progress was obtained through optimization of AlInN growth conditions using an AlInN growth rate of 0.9-nm/min at substrate temperature of 550 °C, as well as by judiciously placing the charge into two delta-doping sheets. Structural characterization suggests that AlInN crystal quality is enhanced and interface roughness is reduced. Importantly, near-infrared absorption data indicate that the optical quality of the AlInN/GaN superlattices is now comparable with that of AlN/GaN superlattices designed to exploit near-infrared intersubband transitions.

  16. On-chip near-infrared spectroscopy of CO2 using high resolution plasmonic filter array

    NASA Astrophysics Data System (ADS)

    Chong, Xinyuan; Li, Erwen; Squire, Kenneth; Wang, Alan X.

    2016-05-01

    We report an ultra-compact, cost-effective on-chip near-infrared spectroscopy system for CO2 sensing using narrow-band optical filter array based on plasmonic gratings with a waveguide layer. By varying the periodicity of the gratings, the transmission spectra of the filters can be continuously tuned to cover the 2.0 μm sensing window with high spectral resolution around 10 nm. Our experimental results show that the on-chip spectroscopy system can resolve the two symmetric vibrational bands of CO2 at 2.0 μm wavelength, which proves its potential to replace the expensive commercial IR spectroscopy system for on-site gas sensing.

  17. Near-infrared spectroscopy for medical applications: Current status and future perspectives.

    PubMed

    Sakudo, Akikazu

    2016-04-01

    The near-infrared radiation (NIR) window, also known as the "optical window" or "therapeutic window", is the range of wavelengths that has the maximum depth of penetration in tissue. Indeed, because NIR is minimally absorbed by water and hemoglobin, spectra readings can be easily collected from the body surface. Recent reports have shown the potential of NIR spectroscopy in various medical applications, including functional analysis of the brain and other tissues, as well as an analytical tool for diagnosing diseases. The broad applicability of NIR spectroscopy facilitates the diagnosis and therapy of diseases as well as elucidating their pathophysiology. This review introduces recent advances and describes new studies in NIR to demonstrate potential clinical applications of NIR spectroscopy. PMID:26877058

  18. [Discrimination of Rice Syrup Adulterant of Acacia Honey Based Using Near-Infrared Spectroscopy].

    PubMed

    Zhang, Yan-nan; Chen, Lan-zhen; Xue, Xiao-feng; Wu, Li-ming; Li, Yi; Yang, Juan

    2015-09-01

    At present, the rice syrup as a low price of the sweeteners was often adulterated into acacia honey and the adulterated honeys were sold in honey markets, while there is no suitable and fast method to identify honey adulterated with rice syrup. In this study, Near infrared spectroscopy (NIR) combined with chemometric methods were used to discriminate authenticity of honey. 20 unprocessed acacia honey samples from the different honey producing areas, mixed? with different proportion of rice syrup, were prepared of seven different concentration gradient? including 121 samples. The near infrared spectrum (NIR) instrument and spectrum processing software have been applied in the? spectrum? scanning and data conversion on adulterant samples, respectively. Then it was analyzed by Principal component analysis (PCA) and canonical discriminant analysis methods in order to discriminating adulterated honey. The results showed that after principal components analysis, the first two principal components accounted for 97.23% of total variation, but the regionalism of the score plot of the first two PCs was not obvious, so the canonical discriminant analysis was used to make the further discrimination, all samples had been discriminated correctly, the first two discriminant functions accounted for 91.6% among the six canonical discriminant functions, Then the different concentration of adulterant samples can be discriminated correctly, it illustrate that canonical discriminant analysis method combined with NIR spectroscopy is not only feasible but also practical for rapid and effective discriminate of the rice syrup adulterant of acacia honey. PMID:26669162

  19. Discriminant analysis of milk adulteration based on near-infrared spectroscopy and pattern recognition

    NASA Astrophysics Data System (ADS)

    Liu, Rong; Lv, Guorong; He, Bin; Xu, Kexin

    2011-03-01

    Since the beginning of the 21st century, the issue of food safety is becoming a global concern. It is very important to develop a rapid, cost-effective, and widely available method for food adulteration detection. In this paper, near-infrared spectroscopy techniques and pattern recognition were applied to study the qualitative discriminant analysis method. The samples were prepared and adulterated with one of the three adulterants, urea, glucose and melamine with different concentrations. First, the spectral characteristics of milk and adulterant samples were analyzed. Then, pattern recognition methods were used for qualitative discriminant analysis of milk adulteration. Soft independent modeling of class analogy and partial least squares discriminant analysis (PLSDA) were used to construct discriminant models, respectively. Furthermore, the optimization method of the model was studied. The best spectral pretreatment methods and the optimal band were determined. In the optimal conditions, PLSDA models were constructed respectively for each type of adulterated sample sets (urea, melamine and glucose) and all the three types of adulterated sample sets. Results showed that, the discrimination accuracy of model achieved 93.2% in the classification of different adulterated and unadulterated milk samples. Thus, it can be concluded that near-infrared spectroscopy and PLSDA can be used to identify whether the milk has been adulterated or not and the type of adulterant used.

  20. Neuronal Correlates of Cognitive Control during Gaming Revealed by Near-Infrared Spectroscopy

    PubMed Central

    Witte, Matthias; Ninaus, Manuel; Kober, Silvia Erika; Neuper, Christa; Wood, Guilherme

    2015-01-01

    In everyday life we quickly build and maintain associations between stimuli and behavioral responses. This is governed by rules of varying complexity and past studies have identified an underlying fronto-parietal network involved in cognitive control processes. However, there is only limited knowledge about the neuronal activations during more natural settings like game playing. We thus assessed whether near-infrared spectroscopy recordings can reflect different demands on cognitive control during a simple game playing task. Sixteen healthy participants had to catch falling objects by pressing computer keys. These objects either fell randomly (RANDOM task), according to a known stimulus-response mapping applied by players (APPLY task) or according to a stimulus-response mapping that had to be learned (LEARN task). We found an increased change of oxygenated and deoxygenated hemoglobin during LEARN covering broad areas over right frontal, central and parietal cortex. Opposed to this, hemoglobin changes were less pronounced for RANDOM and APPLY. Along with the findings that fewer objects were caught during LEARN but stimulus-response mappings were successfully identified, we attribute the higher activations to an increased cognitive load when extracting an unknown mapping. This study therefore demonstrates a neuronal marker of cognitive control during gaming revealed by near-infrared spectroscopy recordings. PMID:26244781

  1. Near-infrared Raman spectroscopy to detect the calcification of the annular mitral valve

    NASA Astrophysics Data System (ADS)

    Rocha, Rick; Otero, E. P.; Costa, M. S.; Villaverde, Antonio G. J. B.; Pomerarantzeff, P. M.; Pacheco, Marcos T. T.

    2004-10-01

    Cardiac valves are subjected to high repetitive mechanical stresses, particularly at the hinge points of the cusps and leaflets due to the over 40 millions cardiac cycles per year. These delicate structures can suffer cumulative lesions, complicated by the deposition of calcium phosphate mineral, which may lead to clinically important disease. Near Infrared Raman Spectroscopy gives important information about biological tissues composition and it is being used for diagnosis of some pathologies. The aim of this work was to detect trough the use of the Raman Spectroscopy technique the mitral annular calcification. A Ti:sapphire laser operating at the near infrared wavelength of 785 nm was used for the excitation of the valve samples and the Raman radiation was detected by an optical spectrometer with a CCD liquid nitrogen cooled detector. In all, ten samples of normal and pathologic tissues were studied. They were approximately squared with the lateral size of 5 mm. It was observed that the Raman spectrum of the calcified mitral valve showed different behavior, when compared to normal tissues. Results indicate that this technique could be used to detect the deposition of the calcium phosphate mineral over the mitral valve.

  2. Development of 200-channel mapping system for tissue oxygenation measured by near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Niwayama, Masatsugu; Kohata, Daisuke; Shao, Jun; Kudo, Nobuki; Hamaoka, Takatumi; Katsumura, Toshihito; Yamamoto, Katsuyuki

    2000-07-01

    Near-infrared spectroscopy (NIRS) is a very useful technique for noninvasive measurement of tissue oxygenation. Among various methods of NIRS, continuous wave near-infrared spectroscopy (CW- NIRS) is especially suitable for real-time measurement and for practical use. CW-NIRS has recently been applied in vivo reflectance imaging of muscle oxygenation and brain activity. However, conventional mapping systems do not have a sufficient mapping area at present. Moreover, they do not enable quantitative measurement of tissue oxygenation because conventional NIRS is based on the inappropriate assumption that tissue is homogeneous. In this study, we developed a 200-channel mapping system that enables measurement of changes in oxygenation and blood volume and that covers a wider area (30 cm x 20 cm) than do conventional systems. The spatial resolution (source- detector separation) of this system is 15 mm. As for the effcts of tissue inhomogeneity on muscle oxygenation measurement, subcutaneous adipose tissue greatly reduces measurement sensitivity. Therefore, we also used a correction method for influence of the subcutaneous fat layer so that we could obtain quantitative changes in concentrations of oxy- and deoxy- hemoglobin. We conducted exercise tests and measured the changed in hemoglobin concentration in the thigh using the new system. The working muscles in the exercises could be imaged, and the heterogeneity of the muscles was shown. These results demonstrated the new 200-channel mapping system enables observation of the distribution of muscle metabolism and localization of muscle function.

  3. [Applied Research in Grade Estimation of Surimi by Near Infrared Spectroscopy].

    PubMed

    Wu, Hao; Chen, Wei-hua; Wang, Xi-chang; Liu, Yuan

    2015-05-01

    The feasibility of utilizing near infrared spectroscopy for estimating frozen and thawed white croaker surimi with different grades was presented in the research. First-derivative and standard normal variable transformation were used as pretreatment method, then principal component analysis was carried out on the processed datas. Establish grade estimation model on white croaker surimi with different grades by principal component analysis-mahalanobis distance pattern recognition method. Seven kinds of physicochemical indexes (moisture, protein, crude fat, salt-soluble protein, gel strength, water-holding ability and whiteness) of white croaker surimi with different grades were determinated. We came to the following conclusions. Firstly, white croaker surimi with three grade could be distinguished effectively by principal component analysis. Secondly, the model of grade estimation established by principal component analysis-mahalanobis distance pattern recognition method had better performance on frozen white croaker surimi than thawed ones, the former's comprehensive accuracy was 96. 3 % with the latter's is 83. 3%. Thirdly, the physicochemical indexes of white croaker surimi with different grades had some distinctions. The research indicated that near infrared spectroscopy could estimate the grade of white croaker surimi rapidly and nondestructively. PMID:26415435

  4. Silicon photomultipliers for improved detection of low light levels in miniature near-infrared spectroscopy instruments.

    PubMed

    Zimmermann, R; Braun, F; Achtnich, T; Lambercy, O; Gassert, R; Wolf, M

    2013-05-01

    Silicon photomultipliers are novel solid state photodetectors that recently became commercially available. The goal of this paper was to investigate their suitability for low light level detection in miniaturized functional near-infrared spectroscopy instruments. Two measurement modules with a footprint of 26×26 mm(2) were built, and the signal-to-noise ratio was assessed for variable source-detector separations between 25 and 65 mm on phantoms with similar optical properties to those of a human head. These measurements revealed that the signal-to-noise ratio of the raw signal was superior to an empirically derived design requirement for source-detector separations up to 50 mm. An arterial arm occlusion was also performed on one of the authors in vivo, to induce reproducible hemodynamic changes which confirmed the validity of the measured signals. The proposed use of silicon photomultipliers in functional near-infrared spectroscopy bears large potential for future development of precise, yet compact and modular instruments, and affords improvements of the source-detector separation by 67% compared to the commonly used 30 mm. PMID:23667783

  5. Cerebral oxygenation and hemodynamic changes during infant cardiac surgery: measurements by near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    du Plessis, Adre J.; Volpe, Joseph J.

    1996-10-01

    Despite dramatic advances in the survival rate among infants undergoing cardiac surgery for congenital heart disease, the incidence of brain injury suffered by survivors remains unacceptably high. This is largely due to our limited understanding of the complex changes in cerebral oxygen utilization and supply occurring during the intraoperative period as a result of hypothermia, neuroactive drugs, and profound circulatory changes. Current techniques for monitoring the adequacy of cerebral oxygen supply and utilization during hypothermic cardiac surgery are inadequate to address this complex problem and consequently to identify the infant at risk for such brain injury. Furthermore, this inability to detect imminent hypoxic- ischemic brain injury is likely to become all the more conspicuous as new neuroprotective strategies, capable of salvaging 'insulated' neuronal tissue form cell death, enter the clinical arena. Near infrared spectroscopy is a relatively new, noninvasive, and portable technique capable of interrogating the oxygenation and hemodynamics of tissue in vivo. These characteristics of the technique have generated enormous interest among clinicians in the ability of near infrared spectroscopy to elucidate the mechanisms of intraoperative brain injury and ultimately to identify infants oat risk for such injury. This paper reviews the experience with this technique to date during infant cardiac surgery.

  6. Determination of chemical composition of commercial honey by near-infrared spectroscopy.

    PubMed

    Qiu, P Y; Ding, H B; Tang, Y K; Xu, R J

    1999-07-01

    The feasibility of using near-infrared spectroscopy to determine chemical composition of commercial honey was examined. The influences of various sample presentation methods and regression models on the performance of calibration equations were also studied. Transmittance spectra with 1 mm optical path length produced the best calibration for all constituents examined. The regression model of modified partial least squares (mPLS) was selected for the calibration of all honey constituents except moisture, for which the optimal calibration was developed with PLS. Validation of the established calibration equations with independent samples showed that the spectroscopic technique could accurately determine the contents of moisture, fructose, glucose, sucrose, and maltose with squared correlation coefficients (R(2)) of 1.0, 0.97, 0.91, 0.86, and 0.93 between the predicted values and the reference values. The prediction accuracy for free acid, lactone, and hydroxymethylfurfural (HMF) contents in honey was poor and unreliable. The study indicates that near-infrared spectroscopy can be used for rapid determination of major components in commercial honey. PMID:10552561

  7. FC-NIRS: A Functional Connectivity Analysis Tool for Near-Infrared Spectroscopy Data

    PubMed Central

    Xu, Jingping; Liu, Xiangyu; Zhang, Jinrui; Li, Zhen; Wang, Xindi; Fang, Fang; Niu, Haijing

    2015-01-01

    Functional near-infrared spectroscopy (fNIRS), a promising noninvasive imaging technique, has recently become an increasingly popular tool in resting-state brain functional connectivity (FC) studies. However, the corresponding software packages for FC analysis are still lacking. To facilitate fNIRS-based human functional connectome studies, we developed a MATLAB software package called “functional connectivity analysis tool for near-infrared spectroscopy data” (FC-NIRS). This package includes the main functions of fNIRS data preprocessing, quality control, FC calculation, and network analysis. Because this software has a friendly graphical user interface (GUI), FC-NIRS allows researchers to perform data analysis in an easy, flexible, and quick way. Furthermore, FC-NIRS can accomplish batch processing during data processing and analysis, thereby greatly reducing the time cost of addressing a large number of datasets. Extensive experimental results using real human brain imaging confirm the viability of the toolbox. This novel toolbox is expected to substantially facilitate fNIRS-data-based human functional connectome studies. PMID:26539473

  8. Neuronal Correlates of Cognitive Control during Gaming Revealed by Near-Infrared Spectroscopy.

    PubMed

    Witte, Matthias; Ninaus, Manuel; Kober, Silvia Erika; Neuper, Christa; Wood, Guilherme

    2015-01-01

    In everyday life we quickly build and maintain associations between stimuli and behavioral responses. This is governed by rules of varying complexity and past studies have identified an underlying fronto-parietal network involved in cognitive control processes. However, there is only limited knowledge about the neuronal activations during more natural settings like game playing. We thus assessed whether near-infrared spectroscopy recordings can reflect different demands on cognitive control during a simple game playing task. Sixteen healthy participants had to catch falling objects by pressing computer keys. These objects either fell randomly (RANDOM task), according to a known stimulus-response mapping applied by players (APPLY task) or according to a stimulus-response mapping that had to be learned (LEARN task). We found an increased change of oxygenated and deoxygenated hemoglobin during LEARN covering broad areas over right frontal, central and parietal cortex. Opposed to this, hemoglobin changes were less pronounced for RANDOM and APPLY. Along with the findings that fewer objects were caught during LEARN but stimulus-response mappings were successfully identified, we attribute the higher activations to an increased cognitive load when extracting an unknown mapping. This study therefore demonstrates a neuronal marker of cognitive control during gaming revealed by near-infrared spectroscopy recordings. PMID:26244781

  9. Paddy soil nutrient assessment using visible and near infrared reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    Gholizadeh, A.; Saberioon, M. M.; Amin, M. S. M.

    The ability of obtaining soil properties estimations from time and cost efficient remotely sensed techniques has been identified as a valuable technique as there is a great demand for larger amounts of good quality and inexpensive soil data to be used in environmental monitoring, modelling and precision agriculture. Visible (Vis) and Near Infrared (NIR) spectroscopy provides a good alternative that may be used to enhance or replace conventional methods of soil analysis. The aim of this paper is to evaluate the abilities of Vis (350-700 nm) and near infrared (700-2500 nm) for prediction of soil nutrients. In this instance we implemented Savitzky-Golay algorithm and Stepwise Multiple Linear Regression (SMLR) to construct calibration models. The soil nutrients examined were soil Total Nitrogen (N), Available Phosphorus (P) and Exchangeable Potassium (K). Our results revealed the accuracy of SMLR prediction in each of the Vis and NIR spectral regions. The NIR produced more accurate predictions for N and K; however, higher significant correlation was obtained using the Vis for available P. This work demonstrated Vis and NIR spectroscopy could be considered as a good tool to assess soil nutrients in Malaysian paddy fields.

  10. Analysis of colon tumors in rats by near-infrared Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Duarte, Janaína; Hage, Raduan; Silveira, Landulfo, Jr.; Silveira, Fabricio; Pacheco, Marcos Tadeu T.; Munin, Egberto; Plapler, Hélio

    2007-02-01

    Biomedical applications of near-infrared Raman spectroscopy have increased their importance at the last ten years. This technique can determinate the molecular composition of materials, allowing a sensible and fast biological diagnosis. It has showed to be a promising tool for health diagnosis due to its high sensibility. Colorectal cancer (CRC) is one of the most common malignant tumors in humans beings. In the last decades many experimental models have been developed in animals based in the use of chemical composites to induce the formation and development of these tumors, many of them present similar characteristics to those of natural occurrence aiming to the attainment of information on genesis, evolution, as well as diagnosis and more efficient therapies for treating these neoplasias. Amongst the most used chemical composites is the 1,2- dimetilhydrazine (DMH) because its morphological and histological similarity to those tumors. This study aims to compare in vivo normal colon tissue and tumoral colon tissue, induced by DMH, in rats by near-infrared Raman spectroscopy to permit the use in the near future for an efficient diagnosis in real time besides being useful as an auxiliary method for several therapies, including the photodynamic therapy.

  11. [Research on zinc content in leaf of Olinda Valencia orange using visible near infrared spectroscopy model].

    PubMed

    Yi, Shi-lai; Deng, Lie; He, Shao-lan; Zheng, Yong-qiang; Wang, Liang; Zhao, Xu-yang

    2010-11-01

    Olinda valencia orange leaves dry powder-like were taken as sample, and chemical analysis combined with technology of visible near-infrared spectroscopy (Vis/NIRS) was used, through the treatment process of second derivative spectrum of samples of the original spectrum and denoising (Noise). Meanwhile, method of partial least squares (PLS) and cross-validation were used to establish maths model of Zn concentration which applying band combination composited by 400-500 and 1201-1300 nm of characteristic wavelength band. The coefficient of establishing models is 0.9975, while the coefficient of correlation coefficient of prediction is 0.9920. The root mean square error of prediction (RMSEP) of cross-validation is 0.5868. Therefore, the means using visible near-infrared spectroscopy (Vis/NIRS) and the methods of cross-validation and PLS to establish the spectral correction model reflecting the Zn content in leaves and characteristic wavelength bands can detect the Zn content in citrus leaves quantitatively and quickly. PMID:21284155

  12. Near-infrared spectroscopy as an auxiliary tool in the study of child development

    PubMed Central

    de Oliveira, Suelen Rosa; Machado, Ana Carolina Cabral de Paula; de Miranda, Débora Marques; Campos, Flávio dos Santos; Ribeiro, Cristina Oliveira; Magalhães, Lívia de Castro; Bouzada, Maria Cândida Ferrarez

    2015-01-01

    OBJECTIVE: To investigate the applicability of Near-Infrared Spectroscopy (NIRS) for cortical hemodynamic assessment tool as an aid in the study of child development. DATA SOURCE: Search was conducted in the PubMed and Lilacs databases using the following keywords: ''psychomotor performance/child development/growth and development/neurodevelopment/spectroscopy/near-infrared'' and their equivalents in Portuguese and Spanish. The review was performed according to criteria established by Cochrane and search was limited to 2003 to 2013. English, Portuguese and Spanish were included in the search. DATA SYNTHESIS: Of the 484 articles, 19 were selected: 17 cross-sectional and two longitudinal studies, published in non-Brazilian journals. The analyzed articles were grouped in functional and non-functional studies of child development. Functional studies addressed the object processing, social skills development, language and cognitive development. Non-functional studies discussed the relationship between cerebral oxygen saturation and neurological outcomes, and the comparison between the cortical hemodynamic response of preterm and term newborns. CONCLUSIONS: NIRS has become an increasingly feasible alternative and a potentially useful technique for studying functional activity of the infant brain. PMID:25862295

  13. Determination of microstructure and composition in butadiene and styrene-butadiene polymers by near-infrared spectroscopy

    SciTech Connect

    Miller, C.E.; Eichinger, B.E. ); Gurley, T.W.; Hermiller, J.G. )

    1990-09-01

    Transmission spectroscopy in the near-infrared region (1,100-2,500 nm) is used to determine the microstructure and the composition of poly(butadiene) (PBD) polymers and styrene-butadiene (SBR) copolymers in bulk and in carbon tetrachloride solution. The multivariate method of classical least squares (CLS) is used to analyze near-infrared spectra of polymers with NMR-determined microstructures and compositions. Although the near-infrared spectra of the pure analytes (cis-1,4-butadiene, trans-1,4-butadiene, 1,2-butadiene, and styrene) are highly overlapped, the CLS method provides accurate predictions of analyte concentrations, because all available spectral frequencies are used for quantitation. The sensitivity of near-infrared spectroscopy to intermolecular interactions and neighboring-group effects in these polymers is demonstrated.

  14. Gasoline classification using near infrared (NIR) spectroscopy data: comparison of multivariate techniques.

    PubMed

    Balabin, Roman M; Safieva, Ravilya Z; Lomakina, Ekaterina I

    2010-06-25

    Near infrared (NIR) spectroscopy is a non-destructive (vibrational spectroscopy based) measurement technique for many multicomponent chemical systems, including products of petroleum (crude oil) refining and petrochemicals, food products (tea, fruits, e.g., apples, milk, wine, spirits, meat, bread, cheese, etc.), pharmaceuticals (drugs, tablets, bioreactor monitoring, etc.), and combustion products. In this paper we have compared the abilities of nine different multivariate classification methods: linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), regularized discriminant analysis (RDA), soft independent modeling of class analogy (SIMCA), partial least squares (PLS) classification, K-nearest neighbor (KNN), support vector machines (SVM), probabilistic neural network (PNN), and multilayer perceptron (ANN-MLP) - for gasoline classification. Three sets of near infrared (NIR) spectra (450, 415, and 345 spectra) were used for classification of gasolines into 3, 6, and 3 classes, respectively, according to their source (refinery or process) and type. The 14,000-8000 cm(-1) NIR spectral region was chosen. In all cases NIR spectroscopy was found to be effective for gasoline classification purposes, when compared with nuclear magnetic resonance (NMR) spectroscopy or gas chromatography (GC). KNN, SVM, and PNN techniques for classification were found to be among the most effective ones. Artificial neural network (ANN-MLP) approach based on principal component analysis (PCA), which was believed to be efficient, has shown much worse results. We hope that the results obtained in this study will help both further chemometric (multivariate data analysis) investigations and investigations in the sphere of applied vibrational (infrared/IR, near-IR, and Raman) spectroscopy of sophisticated multicomponent systems. PMID:20541639

  15. Measuring brain hemodynamic changes in a songbird: responses to hypercapnia measured with functional MRI and near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Vignal, C.; Boumans, T.; Montcel, B.; Ramstein, S.; Verhoye, M.; Van Audekerke, J.; Mathevon, N.; Van der Linden, A.; Mottin, S.

    2008-05-01

    Songbirds have been evolved into models of choice for the study of the cerebral underpinnings of vocal communication. Nevertheless, there is still a need for in vivo methods allowing the real-time monitoring of brain activity. Functional Magnetic Resonance Imaging (fMRI) has been applied in anesthetized intact songbirds. It relies on blood oxygen level-dependent (BOLD) contrast revealing hemodynamic changes. Non-invasive near-infrared spectroscopy (NIRS) is based on the weak absorption of near-infrared light by biological tissues. Time-resolved femtosecond white laser NIRS is a new probing method using real-time spectral measurements which give access to the local variation of absorbing chromophores such as hemoglobins. In this study, we test the efficiency of our time-resolved NIRS device in monitoring physiological hemodynamic brain responses in a songbird, the zebra finch (Taeniopygia guttata), using a hypercapnia event (7% inhaled CO2). The results are compared to those obtained using BOLD fMRI. The NIRS measurements clearly demonstrate that during hypercapnia the blood oxygen saturation level increases (increase in local concentration of oxyhemoglobin, decrease in deoxyhemoglobin concentration and total hemoglobin concentration). Our results provide the first correlation in songbirds of the variations in total hemoglobin and oxygen saturation level obtained from NIRS with local BOLD signal variations.

  16. Near Infrared Spectroscopy of Liquid Hydrocarbon Mixtures for Understanding the Composition of Titan’s Lakes

    NASA Astrophysics Data System (ADS)

    Hadnott, Bryne; Hodyss, Robert; Cable, Morgan; Vu, Tuan; Hayes, Alexander

    2015-11-01

    The presence of ethane and methane lakes on Titan was confirmed by the Cassini Visible and Infrared Mapping Spectrometer (VIMS) data in 2008, and has been investigated in further detail by the Cassini radar instrument (Brown et al, 2008; Pailloue et al, 2008). Modeled compositions suggest that the lakes are predominantly liquid ethane, with liquid methane, propane, and butane; however, pure liquid methane lakes (such as Ligeia Mare) may also be present (Cordier et al, 2009; Mastrogiuseppe et al, 2014). We present a proof-of-concept instrument, consisting of a near infrared (NIR) spectrometer with a fiber optic probe, in order to conduct non-invasive analyses of cryogenic fluids on planetary bodies. To determine the utility of spectroscopy for in-situ studies, we collected transmission spectra of hydrocarbon mixtures, pure methane and ethane endmembers, and nitrogen-saturated hydrocarbons in the NIR region between 900 to 2500 nm; liquid hydrocarbons were measured in a dewar filled with liquid nitrogen, contained within a glove bag pumped with gaseous nitrogen at a total oxygen concentration of < 0.1%. The resultant spectra contained key absorption features that allowed us to determine the relative abundances of each endmember, and the effects temperature and dissolved nitrogen, based on the changes in peak intensity. Peak intensity, as well as integrated absorbance, full-width half-maximum, and peak location were calculated using a multi-peak fitting algorithm; we also adopted a simple linear mixing model which used pure ethane and methane spectra, as well as the measured mixtures, to calculate the linear coefficients of each endmember within the mixture. Resultant plots of changes in peak intensity with temperature (for methane), peak intensity with mole fraction of methane (or ethane), and comparisons of the modeled linear coefficients with the mole fraction of methane (or ethane) added will yield useful data on how methane, ethane, and dissolved nitrogen mix

  17. Cure characterization of an unsaturated polyester resin using near-infrared, fluorescence and UV/visible reflection spectroscopies

    NASA Astrophysics Data System (ADS)

    Grunden, Bradley Lyn

    This dissertation seeks to characterize the cure reaction of an unsaturated polyester resin using near-infrared, fluorescence and UV/Visible reflection spectroscopies. The results will provide a foundation for developing fiber-optic in-situ cure monitoring techniques based on near-infrared, fluorescence, and UV/Visible reflection spectroscopies for an unsaturated polyester resin system. Near-infrared spectra of the unsaturated polyester resin during cure showed a decrease in absorption at 1629, 2087, 2117, and 2227 nm. Model compounds representing the reactants and products of the cure reaction were characterized, and assignment of peaks in the NIR were made. Conversion of styrene and vinylene, determined from NIR measurements, were compared with values obtained using conventional FTIR measurements. Discrepancies between conversion values determined from NIR and FTIR measurements were attributed to a difference in sample sizes used for measurement. Using a microgel based reaction mechanism, the effects of temperature on the conversion of styrene and vinylene was discussed. A strong fluorescence emission was found during cure of the unsaturated polyester resin. As the reaction proceeded, the emission intensity at 306 nm increased. Model compound studies confirmed that the unsaturated polyester vinylene component exhibits negligible fluorescence when excited at 250 nm. The fluorescence emission at 306 nm was attributed to a reduced self-quenching effect of styrene monomer. In-situ fluorescence characterization of the cure reaction was also attempted. Fiber-optic fluorescence measurements taken in-situ at 75°C were found to be higher than those taken by fiber-optics at room temperature, indicating a temperature effect on the fluorescence emission. These results may be a consequence of the static quenching behavior of styrene monomer. UV/Visible reflection spectra of styrene showed a decrease in the % Reflectance at 255 nm with reaction time. This decrease was

  18. Near-infrared spectroscopy and pattern recognition techniques applied to the identification of Jinhua ham

    NASA Astrophysics Data System (ADS)

    Li, Honglian; Zhao, Zhilei; Pang, Yanping; Wu, Guancheng; Wang, Yanfeng; Li, Xiaoting

    2009-11-01

    Near-infrared (NIR) diffuse reflectance spectroscopy and pattern recognition techniques are applied to develop a fast identification method of Jinhua ham. The samples are collected from different manufactures and they are nineteen Jinhua ham samples and four Xuanwei ham samples. NIR spectra are pretreated with second derivative calculation and vector normalization. The pattern recognition techniques which are cluster analysis, conformity test and principal component analysis (PCA) are separately used to qualify Jinhua ham. The three methods can all distinguish Jinhua ham successfully. The result indicated that a 100 % recognition ration is achieved by the methods and the PCA method is the best one. Overall, NIR reflectance spectroscopy using pattern recognition is shown to have significant potential as a rapid and accurate method for identification of ham.

  19. Quantitative determination of the human breast milk macronutrients by near-infrared Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Motta, Edlene d. C. M.; Zângaro, Renato A.; Silveira, Landulfo, Jr.

    2012-03-01

    This work proposes the evaluation of the macronutrient constitution of human breast milk based on the spectral information provided by near-infrared Raman spectroscopy. Human breast milk (5 mL) from a subject was collected during the first two weeks of breastfeeding and stocked in -20°C freezer. Raman spectra were measured using a Raman spectrometer (830 nm excitation) coupled to a fiber based Raman probe. Spectra of human milk were dominated by bands of proteins, lipids and carbohydrates in the 600-1800 cm-1 spectral region. Raman spectroscopy revealed differences in the biochemical constitution of human milk depending on the time of breastfeeding startup. This technique could be employed to develop a classification routine for the milk in Human Milk Banking (HMB) depending on the nutritional facts.

  20. Rapid analysis of polysaccharides contents in Glycyrrhiza by near infrared spectroscopy and chemometrics.

    PubMed

    Zhang, Ci-Hai; Yun, Yong-Huan; Fan, Wei; Liang, Yi-Zeng; Yu, Yue; Tang, Wen-Xian

    2015-08-01

    A method for quantitative analysis of the polysaccharides contents in Glycyrrhiza was developed based on near infrared (NIR) spectroscopy, and by adopting the phenol-sulphuric acid method as the reference method. This is the first time to use this method for predicting polysaccharides contents in Glycyrrhiza. To improve the predictive ability (or robustness) of the model, the competitive adaptive reweighted sampling (CARS) mathematical strategy was used for selecting relevance wavelengths. By using the restricted relevance wavelengths, the PLS model was more efficient and parsimonious. The coefficient of determination of prediction (Rp(2)) and the root mean square error of prediction (RMSEP) of the obtained optimum models were 0.9119 and 0.4350 for polysaccharides. The selected relevance wavelengths were also interpreted. It proved that all the wavelengths selected by CARS were related to functional groups of polysaccharide. The overall results show that NIR spectroscopy combined with chemometrics can be efficiently utilised for analysis of polysaccharides contents in Glycyrrhiza. PMID:26093314

  1. Near Infrared Spectroscopy Detection and Quantification of Herbal Medicines Adulterated with Sibutramine.

    PubMed

    da Silva, Neirivaldo Cavalcante; Honorato, Ricardo Saldanha; Pimentel, Maria Fernanda; Garrigues, Salvador; Cervera, Maria Luisa; de la Guardia, Miguel

    2015-09-01

    There is an increasing demand for herbal medicines in weight loss treatment. Some synthetic chemicals, such as sibutramine (SB), have been detected as adulterants in herbal formulations. In this study, two strategies using near infrared (NIR) spectroscopy have been developed to evaluate potential adulteration of herbal medicines with SB: a qualitative screening approach and a quantitative methodology based on multivariate calibration. Samples were composed by products commercialized as herbal medicines, as well as by laboratory adulterated samples. Spectra were obtained in the range of 14,000-4000 per cm. Using PLS-DA, a correct classification of 100% was achieved for the external validation set. In the quantitative approach, the root mean squares error of prediction (RMSEP), for both PLS and MLR models, was 0.2% w/w. The results prove the potential of NIR spectroscopy and multivariate calibration in quantifying sibutramine in adulterated herbal medicines samples. PMID:26260573

  2. Preparation of a Near-Infrared Ray Absorption Film from N-Phenylthiocarbamoyl Chitosan Derivative

    PubMed Central

    Nishida, Shouko; Shibano, Masaya; Kamitakahara, Hiroshi; Takano, Toshiyuki

    2015-01-01

    We recently observed that the decanoylation of N-phenylthiocarbamoyl chitosan (2) with a mixture of decanoic anhydride and pyridine at 60 °C for 24 h afforded N,N-(decanoyl)phenythiocarbamoyl-/2-isothiocynato chitosan decanoate (3b) rather than the expected product N,N-(decanoyl)phenylthiocarbamoyl chitosan decanoate (3a). This result suggested that some of the N,N-(decanoyl)phenylthiocarmbamoyl groups had been converted to isothiocyanate groups during the decanoylation process. The subsequent reaction of compound 3b with aniline gave N,N-(decanoyl)phenylthiocarbamoyl/N-phenylthiocarbamoyl chitosan decanoate (4) in high yield. A solution of compound 4 in CHCl3 was then added to a solution of copper decanoate (5) in the same solvent, and the resulting mixture was cast onto a glass plate to give a cast film. The film was annealed at 200 °C in an oven to give a greenish film, which showed good near-infrared absorption characteristic in the range of 800–2200 nm. PMID:26690129

  3. Near-infrared light absorption by polycrystalline SiSn alloys grown on insulating layers

    SciTech Connect

    Kurosawa, Masashi; Kato, Motohiro; Yamaha, Takashi; Taoka, Noriyuki; Nakatsuka, Osamu; Zaima, Shigeaki

    2015-04-27

    High-Sn-content SiSn alloys are strongly desired for the next-generation near-infrared optoelectronics. A polycrystalline growth study has been conducted on amorphous SiSn layers with a Sn-content of 2%–30% deposited on either a substrate of SiO{sub 2} or SiN. Incorporating 30% Sn into Si permits the crystallization of the amorphous layers at annealing temperatures below the melting point of Sn (231.9 °C). Composition analyses indicate that approximately 20% of the Sn atoms are substituted into the Si lattice after solid-phase crystallization at 150–220 °C for 5 h. Correspondingly, the optical absorption edge is red-shifted from 1.12 eV (Si) to 0.83 eV (Si{sub 1−x}Sn{sub x} (x ≈ 0.18 ± 0.04)), and the difference between the indirect and direct band gap is significantly reduced from 3.1 eV (Si) to 0.22 eV (Si{sub 1−x}Sn{sub x} (x ≈ 0.18 ± 0.04)). These results suggest that with higher substitutional Sn content the SiSn alloys could become a direct band-gap material, which would provide benefits for Si photonics.

  4. Preparation of a Near-Infrared Ray Absorption Film from N-Phenylthiocarbamoyl Chitosan Derivative.

    PubMed

    Nishida, Shouko; Shibano, Masaya; Kamitakahara, Hiroshi; Takano, Toshiyuki

    2015-01-01

    We recently observed that the decanoylation of N-phenylthiocarbamoyl chitosan (2) with a mixture of decanoic anhydride and pyridine at 60 °C for 24 h afforded N,N-(decanoyl)phenythiocarbamoyl-/2-isothiocynato chitosan decanoate (3b) rather than the expected product N,N-(decanoyl)phenylthiocarbamoyl chitosan decanoate (3a). This result suggested that some of the N,N-(decanoyl)phenylthiocarmbamoyl groups had been converted to isothiocyanate groups during the decanoylation process. The subsequent reaction of compound 3b with aniline gave N,N-(decanoyl)phenylthiocarbamoyl/N-phenylthiocarbamoyl chitosan decanoate (4) in high yield. A solution of compound 4 in CHCl₃ was then added to a solution of copper decanoate (5) in the same solvent, and the resulting mixture was cast onto a glass plate to give a cast film. The film was annealed at 200 °C in an oven to give a greenish film, which showed good near-infrared absorption characteristic in the range of 800-2200 nm. PMID:26690129

  5. Feasibility of field portable near infrared (NIR) spectroscopy to determine cyanide concentrations in soil

    NASA Astrophysics Data System (ADS)

    Sut, Magdalena; Fischer, Thomas; Repmann, Frank; Raab, Thomas

    2013-04-01

    In Germany, at more than 1000 sites, soil is polluted with an anthropogenic contaminant in form of iron-cyanide complexes. These contaminations are caused by former Manufactured Gas Plants (MGPs), where electricity for lighting was produced in the process of coal gasification. The production of manufactured gas was restrained in 1950, which caused cessation of MGPs. Our study describes the application of Polychromix Handheld Field Portable Near-Infrared (NIR) Analyzer to predict the cyanide concentrations in soil. In recent times, when the soil remediation is of major importance, there is a need to develop rapid and non-destructive methods for contaminant determination in the field. In situ analysis enables determination of 'hot spots', is cheap and time saving in comparison to laboratory methods. This paper presents a novel usage of NIR spectroscopy, where a calibration model was developed, using multivariate calibration algorithms, in order to determine NIR spectral response to the cyanide concentration in soil samples. As a control, the contaminant concentration was determined using conventional Flow Injection Analysis (FIA). The experiments revealed that portable near-infrared spectrometers could be a reliable device for identification of contamination 'hot spots', where cyanide concentration are higher than 2400 mg kg-1 in the field and >1750 mg kg-1 after sample preparation in the laboratory, but cannot replace traditional laboratory analyses due to high limits of detection.

  6. Rapid Characterization of Fatty Acids in Oleaginous Microalgae by Near-Infrared Spectroscopy

    PubMed Central

    Liu, Bin; Liu, Jin; Chen, Tianpeng; Yang, Bo; Jiang, Yue; Wei, Dong; Chen, Feng

    2015-01-01

    The key properties of microalgal biodiesel are largely determined by the composition of its fatty acid methyl esters (FAMEs). The gas chromatography (GC) based techniques for fatty acid analysis involve energy-intensive and time-consuming procedures and thus are less suitable for high-throughput screening applications. In the present study, a novel quantification method for microalgal fatty acids was established based on the near-infrared spectroscopy (NIRS) technique. The lyophilized cells of oleaginous Chlorella containing different contents of lipids were scanned by NIRS and their fatty acid profiles were determined by GC-MS. NIRS models were developed based on the chemometric correlation of the near-infrared spectra with fatty acid profiles in algal biomass. The optimized NIRS models showed excellent performances for predicting the contents of total fatty acids, C16:0, C18:0, C18:1 and C18:3, with the coefficient of determination (R2) being 0.998, 0.997, 0.989, 0.991 and 0.997, respectively. Taken together, the NIRS method established here bypasses the procedures of cell disruption, oil extraction and transesterification, is rapid, reliable, and of great potential for high-throughput applications, and will facilitate the screening of microalgal mutants and optimization of their growth conditions for biodiesel production. PMID:25826532

  7. Spectroscopic technique with wide range of wavelength information improves near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Eda, Hideo; Aoki, Hiromichi; Eura, Shigeru; Ebe, Kazutoshi

    2009-02-01

    Near-infrared spectroscopy (NIRS) calculates hemoglobin parameters, such as oxygenated hemoglobin (oxyHb) and deoxygenated hemoglobin (deoxyHb) using the near-infrared light around the wavelength of 800nm. This is based on the modified-Lambert-Beer's law that changes in absorbance are proportional to changes in hemoglobin parameters. Many conventional measurement methods uses only a few wavelengths, however, in this research, basic examination of NIRS measurement was approached by acquiring wide range of wavelength information. Venous occlusion test was performed by using the blood pressure cuff around the upper arm. Pressure of 100mmHg was then applied for about 3 minutes. During the venous occlusion, the spectrum of the lower arm muscles was measured every 15 seconds, within the range of 600 to 1100nm. It was found that other wavelength bands hold information correlating to this venous occlusion task. Technique of improving the performance of NIRS measurement using the Spectroscopic Method is very important for Brain science.

  8. Recent progress in noninvasive diabetes screening by diffuse reflectance near-infrared skin spectroscopy

    NASA Astrophysics Data System (ADS)

    Heise, H. M.; Haiber, S.; Licht, M.; Ihrig, D. F.; Moll, C.; Stuecker, M.

    2006-02-01

    Near infrared spectroscopy exhibits a tremendous potential for clinical chemistry and tissue pathology. Owing to its penetration depth into human skin, near infrared radiation can probe chemical and structural information non-invasively. Metabolic diseases such as diabetes mellitus increase nonenzymatic glycation with the effect of glucose molecules bonding chemically to proteins. In addition, glycation accumulates on tissue proteins with the clearest evidence found in extracellular skin collagen, affecting also covalent crosslinking between adjacent protein strands, which reduces their flexibility, elasticity, and functionality. Non-enzymatically glycated proteins in human skin and following chemical and structural skin changes were our spectroscopic target. We carried out measurements on 109 subjects using two different NIR-spectrometers equipped with diffuse reflection accessories. Spectra of different skin regions (finger and hand/forearm skin) were recorded for comparison with clinical blood analysis data and further patient information allowing classification into diabetics and non-diabetics. Multivariate analysis techniques for supervised classification such as linear discriminant analysis (LDA) were applied using broad spectral interval data or a number of optimally selected wavelengths. Based on fingertip skin spectra recorded by fiber-optics, it was possible to classify diabetics and non-diabetics with a maximum accuracy of 87.8 % using leave-5-out cross-validation (sensitivity of 87.5. %, specificity of 88.2 %). With the results of this study, it can be concluded that ageing and glycation at elevated levels cannot always be separated from each other.

  9. Rapid Characterization of Fatty Acids in Oleaginous Microalgae by Near-Infrared Spectroscopy.

    PubMed

    Liu, Bin; Liu, Jin; Chen, Tianpeng; Yang, Bo; Jiang, Yue; Wei, Dong; Chen, Feng

    2015-01-01

    The key properties of microalgal biodiesel are largely determined by the composition of its fatty acid methyl esters (FAMEs). The gas chromatography (GC) based techniques for fatty acid analysis involve energy-intensive and time-consuming procedures and thus are less suitable for high-throughput screening applications. In the present study, a novel quantification method for microalgal fatty acids was established based on the near-infrared spectroscopy (NIRS) technique. The lyophilized cells of oleaginous Chlorella containing different contents of lipids were scanned by NIRS and their fatty acid profiles were determined by GC-MS. NIRS models were developed based on the chemometric correlation of the near-infrared spectra with fatty acid profiles in algal biomass. The optimized NIRS models showed excellent performances for predicting the contents of total fatty acids, C16:0, C18:0, C18:1 and C18:3, with the coefficient of determination (R2) being 0.998, 0.997, 0.989, 0.991 and 0.997, respectively. Taken together, the NIRS method established here bypasses the procedures of cell disruption, oil extraction and transesterification, is rapid, reliable, and of great potential for high-throughput applications, and will facilitate the screening of microalgal mutants and optimization of their growth conditions for biodiesel production. PMID:25826532

  10. In vivo, noninvasive measurement of muscle pH during exercise using near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Soyemi, Olusola; Shear, Michael; Landry, Michelle; Anunciacion, Dulce; Soller, Babs

    2005-11-01

    Muscle pH is an important indicator of inadequate blood flow and available oxygen. Muscle pH can be used to triage and help treat trauma victims and indicate poor peripheral blood flow in diabetic patients. Muscle pH can also be used to indicate exercise intensity and fatigue. We have developed methods to non-invasively measure muscle pH using Near-Infrared Spectroscopy (NIRS) and Partial Least Squares (PLS) analysis. A multi-subject PLS model correlating near infrared tissue spectra, acquired from healthy subjects during repetitive hand-grip exercise, to invasive tissue pH measurements, has been developed and validated. Subject related variations in the spectral signal; impede the development of viable multi-subject model. Within-subject variations in tissue NIR spectra often result from uncontrolled motion or blood volume changes during exercise, while subject-to-subject variations arise from differences in skin pigmentation and the fat layer thickness. We have developed signal processing techniques to account for these mitigating factors. By incorporating this signal processing techniques with PLS calibration, we can generate a pH model that has a relative standard error of prediction of 1.7%

  11. Simulation of Near-Infrared Light Absorption Considering Individual Head and Prefrontal Cortex Anatomy: Implications for Optical Neuroimaging

    PubMed Central

    Hahn, Tim; Schecklmann, Martin; Ehlis, Ann-Christine; Fallgatter, Andreas J.

    2011-01-01

    Functional near-infrared spectroscopy (fNIRS) is an established optical neuroimaging method for measuring functional hemodynamic responses to infer neural activation. However, the impact of individual anatomy on the sensitivity of fNIRS measuring hemodynamics within cortical gray matter is still unknown. By means of Monte Carlo simulations and structural MRI of 23 healthy subjects (mean age: years), we characterized the individual distribution of tissue-specific NIR-light absorption underneath 24 prefrontal fNIRS channels. We, thereby, investigated the impact of scalp-cortex distance (SCD), frontal sinus volume as well as sulcal morphology on gray matter volumes () traversed by NIR-light, i.e. anatomy-dependent fNIRS sensitivity. The NIR-light absorption between optodes was distributed describing a rotational ellipsoid with a mean penetration depth of considering the deepest of light. Of the detected photon packages scalp and bone absorbed and absorbed of the energy. The mean volume was negatively correlated () with the SCD and frontal sinus volume () and was reduced by in subjects with relatively large compared to small frontal sinus. Head circumference was significantly positively correlated with the mean SCD () and the traversed frontal sinus volume (). Sulcal morphology had no significant impact on . Our findings suggest to consider individual SCD and frontal sinus volume as anatomical factors impacting fNIRS sensitivity. Head circumference may represent a practical measure to partly control for these sources of error variance. PMID:22039475

  12. Near-infrared optical absorption enhanced in black silicon via Ag nanoparticle-induced localized surface plasmon

    PubMed Central

    2014-01-01

    Due to the localized surface plasmon (LSP) effect induced by Ag nanoparticles inside black silicon, the optical absorption of black silicon is enhanced dramatically in near-infrared range (1,100 to 2,500 nm). The black silicon with Ag nanoparticles shows much higher absorption than black silicon fabricated by chemical etching or reactive ion etching over ultraviolet to near-infrared (UV-VIS-NIR, 250 to 2,500 nm). The maximum absorption even increased up to 93.6% in the NIR range (820 to 2,500 nm). The high absorption in NIR range makes LSP-enhanced black silicon a potential material used for NIR-sensitive optoelectronic device. PACS 78.67.Bf; 78.30.Fs; 78.40.-q; 42.70.Gi PMID:25285058

  13. Near-infrared-excited confocal Raman spectroscopy advances in vivo diagnosis of cervical precancer

    NASA Astrophysics Data System (ADS)

    Duraipandian, Shiyamala; Zheng, Wei; Ng, Joseph; Low, Jeffrey J. H.; Ilancheran, Arunachalam; Huang, Zhiwei

    2013-06-01

    Raman spectroscopy is a unique optical technique that can probe the changes of vibrational modes of biomolecules associated with tissue premalignant transformation. This study evaluates the clinical utility of confocal Raman spectroscopy over near-infrared (NIR) autofluorescence (AF) spectroscopy and composite NIR AF/Raman spectroscopy for improving early diagnosis of cervical precancer in vivo at colposcopy. A rapid NIR Raman system coupled with a ball-lens fiber-optic confocal Raman probe was utilized for in vivo NIR AF/Raman spectral measurements of the cervix. A total of 1240 in vivo Raman spectra [normal (n=993), dysplasia (n=247)] were acquired from 84 cervical patients. Principal components analysis (PCA) and linear discriminant analysis (LDA) together with a leave-one-patient-out, cross-validation method were used to extract the diagnostic information associated with distinctive spectroscopic modalities. The diagnostic ability of confocal Raman spectroscopy was evaluated using the PCA-LDA model developed from the significant principal components (PCs) [i.e., PC4, 0.0023% PC5, 0.00095% PC8, 0.00022%, (p<0.05)], representing the primary tissue Raman features (e.g., 854, 937, 1095, 1253, 1311, 1445, and 1654 cm-1). Confocal Raman spectroscopy coupled with PCA-LDA modeling yielded the diagnostic accuracy of 84.1% (a sensitivity of 81.0% and a specificity of 87.1%) for in vivo discrimination of dysplastic cervix. The receiver operating characteristic curves further confirmed that the best classification was achieved using confocal Raman spectroscopy compared to the composite NIR AF/Raman spectroscopy or NIR AF spectroscopy alone. This study illustrates that confocal Raman spectroscopy has great potential to improve early diagnosis of cervical precancer in vivo during clinical colposcopy.

  14. Near-Infrared (NIR) Spectroscopy of Synthetic Hydroxyapatites and Human Dental Tissues.

    PubMed

    Kolmas, Joanna; Marek, Dariusz; Kolodziejski, Waclaw

    2015-08-01

    Near-infrared spectroscopy (NIR) was used to analyze synthetic hydroxyapatite calcined at various temperatures, synthetic carbonated hydroxyapatite, and human hard dental tissues (enamel and dentin). The NIR bands of those materials in the combination, first-overtone, and second-overtone spectral regions were assigned and evaluated for structural characterization. They were attributed to adsorbed and structural water, structural hydroxyl (OH) groups and surface P-OH groups. The NIR spectral features were quantitatively discussed in view of proton solid-state magic-angle spinning nuclear magnetic resonance ((1)H MAS NMR) results. We conclude that the NIR spectra of apatites are useful in the structural characterization of synthetic and biogenic apatites. PMID:26163232

  15. Quantitative near-infrared spectroscopy on patients with peripheral vascular disease

    NASA Astrophysics Data System (ADS)

    Franceschini, Maria-Angela; Fantini, Sergio; Palumbo, Renato; Pasqualini, Leonella; Vaudo, Gaetano; Franceschini, Edoardo; Gratton, Enrico; Palumbo, Barbara; Innocente, Salvatore; Mannarino, Elmo

    1998-01-01

    We have used near-infrared spectroscopy to measure the hemoglobin saturation at rest and during exercise on patients affected by peripheral vascular disease (PVD). The instrument used in our study is a frequency-domain tissue oximeter which employs intensity modulated (110 MHz) laser diodes. We examined 9 subjects, 3 of which were controls and 6 were patients affected by stage II PVD. The optical probe was located on the calf muscle of the subjects. The measurement protocol consisted of: (1) baseline (approximately 5 min); (2) stationary bicycle exercise (approximately 5 min); (3) recovery (approximately 15 min). The change in hemoglobin saturation during exercise ((Delta) Y) and the recovery time after exercise (trec) were significantly greater in the PVD patients ((Delta) Y equals -21 +/- 3%, trec equals 5.9 +/- 3.8 min) than in the control subjects ((Delta) Y equals 2 +/- 3%, trec equals 0.6 +/- 0.1 min).

  16. Quantitative near-infrared spectroscopy on patients with peripheral vascular disease

    NASA Astrophysics Data System (ADS)

    Franceschini, Maria A.; Fantini, Sergio; Palumbo, Renato; Pasqualini, Leonella; Vaudo, Gaetano; Franceschini, Edoardo; Gratton, Enrico; Palumbo, Barbara; Innocente, Salvatore; Mannarino, Elmo

    1997-12-01

    We have used near-infrared spectroscopy to measure the hemoglobin saturation at rest and during exercise on patients affected by peripheral vascular disease (PVD). The instrument used in our study is a frequency-domain tissue oximeter which employs intensity modulated (110 MHz) laser diodes. We examined 9 subjects, 3 of which were controls and 6 were patients affected by stage II PVD. The optical probe was located on the calf muscle of the subjects. The measurement protocol consisted of: (1) baseline (approximately 5 min); (2) stationary bicycle exercise (approximately 5 min); (3) recovery (approximately 15 min). The change in hemoglobin saturation during exercise ((Delta) Y) and the recovery time after exercise (trec) were significantly greater in the PVD patients ((Delta) Y equals -21 +/- 3%, trec equals 5.9 +/- 3.8 min) than in the control subjects ((Delta) Y equals 2 +/- 3%, trec equals 0.6 +/- 0.1 min).

  17. [Use of visible and near infrared reflectance spectroscopy to identify the cashmere and wool].

    PubMed

    Liu, Xin-Ru; Zhang, Li-Ping; Wang, Jian-Fu; Wu, Jian-Ping; Wang, Xin-Rong

    2013-08-01

    The wool and cashmere samples (n = 130) from different areas of Gansu province were identified by visible and near-infrared reflectance spectroscopy (Vis/NIRs). The result shows that principal component-mahalanobis distance pattern can identify the wool and cashmere, and the boundary between two categories was clear; The calibration set samples were used to establish calibration qualitative model using PCR combined with the best pretreatment of the spectra and math, including multivariate scattering correction (MSC), first derivative, eight for the best principal component factor, one for uncertainty factor, this calibration model of the predicted was the best, and the result of the external validation was correct completely. Results from this experiment indicate that Vis/NIRs can be utilized to identify the wool and cashmere. PMID:24159853

  18. Chilean flour and wheat grain: tracing their origin using near infrared spectroscopy and chemometrics.

    PubMed

    González-Martín, Ma Inmaculada; Wells Moncada, Guillermo; González-Pérez, Claudio; Zapata San Martín, Nelson; López-González, Fernando; Lobos Ortega, Iris; Hernández-Hierro, Jose-Miguel

    2014-02-15

    Instrumental techniques such a near-infrared spectroscopy (NIRS) are used in industry to monitor and establish product composition and quality. As occurs with other food industries, the Chilean flour industry needs simple, rapid techniques to objectively assess the origin of different products, which is often related to their quality. In this sense, NIRS has been used in combination with chemometric methods to predict the geographic origin of wheat grain and flour samples produced in different regions of Chile. Here, the spectral data obtained with NIRS were analysed using a supervised pattern recognition method, Discriminat Partial Least Squares (DPLS). The method correctly classified 76% of the wheat grain samples and between 90% and 96% of the flour samples according to their geographic origin. The results show that NIRS, together with chemometric methods, provides a rapid tool for the classification of wheat grain and flour samples according to their geographic origin. PMID:24128548

  19. Plasmonic filter array for on-chip near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Li, Erwen; Chong, Xinyuan; Ren, Fanghui; Wang, Alan X.

    2016-03-01

    We demonstrate an ultra-compact on-chip spectrometer for near-infrared (NIR) spectroscopy based on narrow-band band-pass filter array. Each individual filter consists of a plasmonic metallic grating with subwavelength period and extremely narrow slits on a quartz substrate, with a polymer cover layer as the waveguide layer. A narrow-band guided-mode resonance (GMR) associated with a surface-plasmon resonance (SPR) gives rise to the narrow-band transmission spectrum. Full width at half maximum (FWHM) of fabricated filter's spectrum is measured to be from 7 to 13 nm, and the operation bandwidth of the entire filter array covers wavelength range over 270 nm from 1510 to 1780 nm. We measure the NIR absorbance spectrum of xylene using our filter array device to demonstrate its application as a spectrometer.

  20. Near-infrared autofluorescence spectroscopy of in vivo soft tissue sarcomas

    PubMed Central

    Nguyen, John Quan; Gowani, Zain; O'Connor, Maggie; Pence, Isaac; Nguyen, The-Quyen; Holt, Ginger; Mahadevan-Jansen, Anita

    2016-01-01

    Soft tissue sarcomas (STS) are a rare and heterogeneous group of malignant tumors that are often treated via surgical resection. Inadequate resection can lead to local recurrence and decreased survival rates. In this study, we investigate the hypothesis that near-infrared (NIR) autofluorescence can be utilized for tumor margin analysis by differentiating STS from the surrounding normal tissue. Intraoperative in vivo measurements were acquired from 30 patients undergoing STS resection and were characterized to differentiate between normal tissue and STS. Overall, normal muscle and fat were observed to have the highest and lowest autofluorescence intensities, respectively, with STS falling in between. With the exclusion of well-differentiated liposarcomas, the algorithm's accuracy for classifying muscle, fat, and STS was 93%, 92%, and 88%, respectively. These findings suggest that NIR autofluorescence spectroscopy has potential as a rapid and nondestructive surgical guidance tool that can inform surgeons of suspicious margins in need of immediate re-excision. PMID:26625035

  1. Extraction of heart rate from functional near-infrared spectroscopy in infants

    NASA Astrophysics Data System (ADS)

    Perdue, Katherine L.; Westerlund, Alissa; McCormick, Sarah A.; Nelson, Charles A.

    2014-06-01

    Changes in heart rate are a useful physiological measure in infant studies. We present an algorithm for calculating the heart rate (HR) from oxyhemoglobin pulsation in functional near-infrared spectroscopy (fNIRS) signals. The algorithm is applied to data collected from 10 infants, and the HR derived from the fNIRS signals is compared against the HR as calculated by electrocardiography. We show high agreement between the two HR signals for all infants (r>0.90), and also compare stimulus-related HR responses as measured by the two methods and find good agreement despite high levels of movement in the infants. This algorithm can be used to measure changes in HR in infants participating in fNIRS studies without the need for additional HR sensors.

  2. Characterizing emotional response to music in the prefrontal cortex using near infrared spectroscopy.

    PubMed

    Moghimi, Saba; Kushki, Azadeh; Guerguerian, Anne Marie; Chau, Tom

    2012-09-01

    Known to be involved in emotional processing the human prefrontal cortex (PFC), can be non-invasively monitored using near-infrared spectroscopy (NIRS). As such, PFC NIRS can serve as a means for studying emotional processing by the PFC. Identifying patterns associated with emotions in PFC using NIRS may provide a means of bedside emotion identification for nonverbal children and youth with severe physical disabilities. In this study, NIRS was used to characterize the PFC hemodynamic response to emotional arousal and valence in a music-based emotion induction paradigm in 9 individuals without disabilities or known health conditions. In particular, a novel technique based on wavelet-based peak detection was used to characterize chromophore concentration patterns. The maximum wavelet coefficients extracted from oxygenated hemoglobin concentration waveforms from all nine recording locations on the PFC were significantly associated with emotional valence and arousal. Specifically, high arousal and negative emotions were associated with larger maximum wavelet coefficients. PMID:22842396

  3. Histochemical analysis of human coronary artery using near-infrared Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Brennan, James F., III; Roemer, Tjeerd J.; Wang, Yang; Fitzmaurice, Maryann; Lees, Robert S.; Kramer, John R., Jr.; Feld, Michael S.

    1995-01-01

    We are developing a method to quantitatively analyze the biochemical composition of human coronary artery in situ using near-infrared Raman spectroscopy. Samples of normal artery (intima/media and adventitia) and noncalcified and calcified plaque from coronary arteries, obtained from explanted recipient hearts during heart transplantation, were illuminated with 830 nm excitation light from a CW Ti:sapphire laser. Raman spectra were collected in seconds using a spectrograph and a cooled, deep-depletion CCD detector, and calibration and background corrections were made. Artery samples in different stages of atherosclerosis exhibited distinct spectral features, providing clear histochemical indicators for characterizing the type and extent of the lesion. Spectra were analyzed by means of a Raman biochemical assay model to determine the relative weight fractions of cholesterols, triacylglycerol, proteins and calcium minerals. Such information, when obtained clinically, promises to be useful in diagnosing and studying human atherosclerosis, its progression and response to drug therapy.

  4. Sleep apnea termination decreases cerebral blood volume: a near-infrared spectroscopy case study

    NASA Astrophysics Data System (ADS)

    Virtanen, Jaakko; Noponen, Tommi; Salmi, Tapani; Toppila, Jussi; Meriläinen, Pekka

    2009-07-01

    Medical near-infrared spectroscopy (NIRS) can be used to estimate cerebral haemodynamic changes non-invasively. Sleep apnea is a common sleep disorder where repetitive pauses in breathing decrease the quality of sleep and exposes the individual to various health problems. We have measured oxygenated and deoxygenated haemoglobin concentration changes during apneic events in sleep from the forehead of one subject using NIRS and used principal component analysis to extract extracerebral and cortical haemodynamic changes from NIRS signals. Comparison of NIRS signals with EEG, bioimpedance, and pulse oximetry data suggests that termination of apnea leads to decreases in cerebral blood volume and flow that may be related to neurological arousal via neurovascular coupling.

  5. Systematic optimization of MRI guided near infrared diffuse optical spectroscopy in breast

    NASA Astrophysics Data System (ADS)

    Zhao, Yan; Mastanduno, Michael A.; Jiang, Shudong; El-Ghussein, Fadi; Xu, Junqing; Gui, Jiang; Pogue, Brian W.; Paulsen, Keith D.

    2015-03-01

    A hybrid frequency domain (FD)-continuous wave (CW) MRI/NIRS system was validated in a clinical trial involving patients with at least ACR 4 radiologic findings in Xi'an, China. In this study, MRI guided nonlinear iterative reconstruction of near-infrared spectroscopy (NIRS) images with limited phase data is investigated. In addition, a systematic optimization of the system hardware design has been conducted as well. We are able to get less than 3% variation in tumor contrast to the surrounding normal tissue, by reducing the number of FD detectors from 16 to 6, showing the potential of reducing the FD detectors. Furthermore, a lookup table of the scattering properties has been made by averaging four MRI-identified breast density groups. By using this look-up table for the patient with the noisy phase data, similar AUCs and p-values are achieved for differentiating the malignant from benign patients.

  6. Intraoperative 16-Channel Electroencephalography and Bilateral Near Infrared Spectroscopy Monitorization in Aortic Surgery

    PubMed Central

    Demir, Aslı; Aydınlı, Bahar; Ünal, Ertekin Utku; Bindal, Mustafa; Koçulu, Rabia; Sarıtaş, Ahmet; Karadeniz, Ümit

    2015-01-01

    Transient neurologic dysfunction is common after aortic surgery. Major causes of postoperative complications followed by cardiac surgery are due to hypoperfusion states such as selective cerebral perfusion, embolic debris during cardiopulmonary bypass and ulcerated plaque emboli originated from carotid arteries. Neurologic complications prolong periods of intensive care unit and hospital stay, worsens quality of life and unfortunately they are an important cause of morbidity. Anaesthesia during a carotid and aortic surgery constitutes of providing adequate brain perfusion pressure, attenuating cerebral metabolism by anaesthetic agents and monitoring the cerebral metabolic supply and demand relationship during the intraoperative period. We present a monitoring approach with an intraoperative 16-channel electroencephalography and bilateral near infrared spectroscopy during redo aneurysm of the sinus of Valsalva surgery. PMID:27366510

  7. Hemodynamic correlates of visuomotor motor adaptation by functional Near Infrared Spectroscopy.

    PubMed

    Gentili, Rodolphe J; Hadavi, Cyrus; Ayaz, Hasan; Shewokis, Patricia A; Contreras-Vidal, Jose L

    2010-01-01

    The development of rehabilitation engineering technologies such as the design of smart prosthetics necessitates a deep understanding of brain mechanisms engaged in ecological situations when human interact with new tools and/or environments. Thus, we aimed to investigate potential hemodynamic signatures reflecting the level of cognitive-motor performance and/or the internal or mental states of individuals when learning a novel tool with unknown properties. These markers were derived from functional Near Infrared Spectroscopy (fNIR) signals. Our results indicate an increased level of oxy-hemoglobin in prefrontal sensors associated with enhanced kinematics during early compared with late learning. This is consistent with previous neuroimaging studies that revealed a higher contribution of prefrontal areas during early compare to late adaptation learning. These non-invasive functional hemodynamic markers may play a role in bioengineering applications such as smart neuroprosthesis and brain monitoring where adaptive behavior is important. PMID:21095985

  8. Studying brain function with near-infrared spectroscopy concurrently with electroencephalography

    NASA Astrophysics Data System (ADS)

    Tong, Y.; Rooney, E. J.; Bergethon, P. R.; Martin, J. M.; Sassaroli, A.; Ehrenberg, B. L.; Van Toi, Vo; Aggarwal, P.; Ambady, N.; Fantini, S.

    2005-04-01

    Near-infrared spectroscopy (NIRS) has been used for functional brain imaging by employing properly designed source-detector matrices. We demonstrate that by embedding a NIRS source-detector matrix within an electroencephalography (EEG) standard multi-channel cap, we can perform functional brain mapping of hemodynamic response and neuronal response simultaneously. In this study, the P300 endogenous evoked response was generated in human subjects using an auditory odd-ball paradigm while concurrently monitoring the hemodynamic response both spatially and temporally with NIRS. The electrical measurements showed the localization of evoked potential P300, which appeared around 320 ms after the odd-ball stimulus. The NIRS measurements demonstrate a hemodynamic change in the fronto-temporal cortex a few seconds after the appearance of P300.

  9. Extraction of heart rate from functional near-infrared spectroscopy in infants

    PubMed Central

    Perdue, Katherine L.; Westerlund, Alissa; McCormick, Sarah A.; Nelson, Charles A.

    2014-01-01

    Abstract. Changes in heart rate are a useful physiological measure in infant studies. We present an algorithm for calculating the heart rate (HR) from oxyhemoglobin pulsation in functional near-infrared spectroscopy (fNIRS) signals. The algorithm is applied to data collected from 10 infants, and the HR derived from the fNIRS signals is compared against the HR as calculated by electrocardiography. We show high agreement between the two HR signals for all infants (r>0.90), and also compare stimulus-related HR responses as measured by the two methods and find good agreement despite high levels of movement in the infants. This algorithm can be used to measure changes in HR in infants participating in fNIRS studies without the need for additional HR sensors. PMID:24972361

  10. Elevated Skin Blood Flow Influences Near Infrared Spectroscopy Measurements During Supine Rest

    NASA Technical Reports Server (NTRS)

    Lee, Stuart M. C.; Clarke, Mark S. F.

    2004-01-01

    Near infrared spectroscopy is a non-invasive technique that allows determination of tissue oxygenation/blood flow based on spectrophotometric quantitation of oxy- and deoxyhemoglobin present within a tissue. This technique has gained acceptance as a means of detecting and quantifying changes in tissue blood flow due to physiological perturbation, such as that which is elicited in skeletal muscle during exercise. Since the NIRS technique requires light to penetrate the skin and subcutaneous fat in order to reach the muscle of interest, changes in skin blood flow may alter the NIRS signal in a fashion unrelated to blood flow in the muscle of interest. The aim of this study was to determine the contribution of skin blood flow to the NIRS signal obtained from resting vastus lateralis muscle of the thigh.

  11. Measurement of triglycerides concentration in human serum using near-infrared transmission spectroscopy and interval PLS

    NASA Astrophysics Data System (ADS)

    Huang, Furong; Yu, Jianhui; Li, Shiping

    2011-11-01

    In order to measurement of Triglycerides in human serum with reagent-less using near-infrared (NIR) spectroscopy. Interval partial least square (iPLS) was proposed as an effective variable selection approach for multivariate calibration. For this purpose, an independent sample set was employed to evaluate the prediction ability of the resulting model. The spectrum was split into different interval. Then, the informative region of Triglycerides (1654-1746nm), in which the PLS model has a low RMSEP with 0.157mmol/L and a high R with 0.967, is selected with 18 intervals. The results show that the informative region of Triglycerides can be obtained by iPLS and applied to design the simpler reagent-less NIR instruments for inexpensive Triglycerides measurement in future.

  12. Sediment mineralogy based on visible and near-infrared reflectance spectroscopy

    USGS Publications Warehouse

    Jarrard, R.D.; Vanden Berg, M.D.

    2006-01-01

    Visible and near-infrared spectroscopy (VNIS) can be used to measure reflectance spectra (wavelength 350-2500 nm) for sediment cores and samples. A local ground-truth calibration of spectral features to mineral percentages is calculated by measuring reflectance spectra for a suite of samples of known mineralogy. This approach has been tested on powders, core plugs and split cores, and we conclude that it works well on all three, unless pore water is present. Initial VNIS studies have concentrated on determination of relative proportions of carbonate, opal, smectite and illite in equatorial Pacific sediments. Shipboard VNIS-based determination of these four components was demonstrated on Ocean Drilling Program Leg 199. ?? The Geological Society of London 2006.

  13. Near-infrared spectroscopy (NIRS) as a new tool for neuroeconomic research

    PubMed Central

    Kopton, Isabella M.; Kenning, Peter

    2014-01-01

    Over the last decade, the application of neuroscience to economic research has gained in importance and the number of neuroeconomic studies has grown extensively. The most common method for these investigations is fMRI. However, fMRI has limitations (particularly concerning situational factors) that should be countered with other methods. This review elaborates on the use of functional Near-Infrared Spectroscopy (fNIRS) as a new and promising tool for investigating economic decision making both in field experiments and outside the laboratory. We describe results of studies investigating the reliability of prototype NIRS studies, as well as detailing experiments using conventional and stationary fNIRS devices to analyze this potential. This review article shows that further research using mobile fNIRS for studies on economic decision making outside the laboratory could be a fruitful avenue helping to develop the potential of a new method for field experiments outside the laboratory. PMID:25147517

  14. [Quantitative analysis of contents in compound fertilizer and application research using near infrared reflectance spectroscopy].

    PubMed

    Song, Le; Zhang, Hong; Ni, Xiao-Yu; Wu, Lin; Liu, Bin-Mei; Yu, Li-Xiang; Wang, Qi; Wu, Yue-Jin

    2014-01-01

    In the present study, a new approach to fast determining the content of urea, biuret and moisture in compound fertilizer composed of urea, ammonium dihydrogenphosphate and potassium chloride was proposed by using near infrared diffuse reflectance spectroscopy. After preprocessing the original spectrum, partial least squares (PLS) models of urea, biuret and moisture were built with the R2 values of 0.9861, 0.9770 and 0.9713 respectively, the root mean square errors of cross validation were 2.59, 0.38, 0.132 respectively. And the prediction correlation factors were 0.9733, 0.9215 and 0.9679 respectively. The authors detected six kinds of compound fertilizer in market for the model verification, the correlation factors were 0.9237, 0.9786 and 0.9874 respectively. The data implied that the new method can be used for situ quality control in the production process of compound fertilizer. PMID:24783536

  15. Optical system for measurement of internal pear quality using near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Liu, Yande; Ying, Yibin

    2005-07-01

    An optical system based on Fourier transform near-infrared spectroscopy for nondestructive measurement of internal quality in intact fruit was developed. This system consisted of a light source, interferometer, fiber optical sensor, InGaAs detector, data collection card, and fruit holder. Quantification tests for sugar content (SC) and titratable acidity (TA) of 248 pear samples were carried out by using the multivariate calibration technique of partial least squares (PLS). The calibration model for SC and TA gave correlation coefficients of determination of 0.867 and 0.793, standard errors of calibration of 0.256 and 0.020, and standard errors of prediction of 0.320 and 0.019, respectively. Experimental results show that this optical system could be directly applied to fast quantification analysis for internal quality of fruits.

  16. Rapid and Accurate Evaluation of the Quality of Commercial Organic Fertilizers Using Near Infrared Spectroscopy

    PubMed Central

    Wang, Chang; Huang, Chichao; Qian, Jian; Xiao, Jian; Li, Huan; Wen, Yongli; He, Xinhua; Ran, Wei; Shen, Qirong; Yu, Guanghui

    2014-01-01

    The composting industry has been growing rapidly in China because of a boom in the animal industry. Therefore, a rapid and accurate assessment of the quality of commercial organic fertilizers is of the utmost importance. In this study, a novel technique that combines near infrared (NIR) spectroscopy with partial least squares (PLS) analysis is developed for rapidly and accurately assessing commercial organic fertilizers quality. A total of 104 commercial organic fertilizers were collected from full-scale compost factories in Jiangsu Province, east China. In general, the NIR-PLS technique showed accurate predictions of the total organic matter, water soluble organic nitrogen, pH, and germination index; less accurate results of the moisture, total nitrogen, and electrical conductivity; and the least accurate results for water soluble organic carbon. Our results suggested the combined NIR-PLS technique could be applied as a valuable tool to rapidly and accurately assess the quality of commercial organic fertilizers. PMID:24586313

  17. [Application of near-infrared reflectance spectroscopy in grass breeding with space flight mutagenesis].

    PubMed

    Ren, Wei-Bo; Han, Jian-Guo; Zhang, Yun-Wei; Guo, Hui-Qin

    2008-02-01

    Near infrared reflectance spectroscopy is a new fast and efficient analysis method. It has been wildly used in many areas such as evaluation of feedstuff, assessment of soil fertilizer and so on. In the present paper, the principle, technique method and merits of NIRS were introduced. The potential application of NIRS in grass breeding with space flight mutagenesis was discussed in areas such as analysis of grass nutrition, estimate of secondary metabolism compounds, forecast of disease and insects resistance, and evaluation of abiotic stress. The conclusion is that application of NIRS in grass breeding with space mutagenesis is significant in both academic and technical areas because it not only improves the efficiency of mutation selection but helps uncover the mechanism of space mutation breeding. PMID:18479009

  18. Neonatal intensive care: an obvious, yet difficult area for cerebral near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Skov, Lotte; Brun, Nikolai C.; Greisen, Gorm

    1997-01-01

    The first clinical application of near-infrared spectroscopy (NIRS) 11 years go was on the head of newborn infants under intensive care. Since then much credible and some important data have been accumulated in this area of research. The best data have been obtained using manipulation of arterial oxygen saturation to obtain single or repeated estimates of cerebral blood flow or cerebral blood volume, or interference with cerebral venous return to obtain measures of venous oxygen saturation. It has been more difficult to take advantage of the continuous and noninvasive nature of NIRS. In particular, the value of the cytochrome signal can still be doubted. A role has not yet developed for NIRS in clinical neonatology.

  19. Calibration and prediction of amino acids in stevia leaf powder using near infrared reflectance spectroscopy.

    PubMed

    Li, Guan; Wang, Ruiguo; Quampah, Alfred Julius; Rong, Zhengqin; Shi, Chunhai; Wu, Jianguo

    2011-12-28

    The use of stevia as animal feed additive has been researched over the years, but how to rapidly predict its amino acid contents has not been studied yet by using near-infrared reflectance spectroscopy. In the present study, 301 samples of stevia leaf powder were defined as the calibration set from which calibration models were optimized, and the performance of prediction was evaluated. Compared with other mathematical treatments, the models developed with the "1, 12, 12, 1" treatment, combined with modified partial least-squares regression and standard normal variance with de-trending, had a significant potential in predicting amino acid contents, such as threonine, serine, etc. Six spectral regions were found to possess large spectrum variation and show high contribution to calibration models. From the present study, the calibration models of amino acids in stevia were successfully developed and could be applied to quality control in feed processing, breeding selection and mutant screening. PMID:22066716

  20. Fast determination of total ginsenosides content in ginseng powder by near infrared reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    Chen, Hua-cai; Chen, Xing-dan; Lu, Yong-jun; Cao, Zhi-qiang

    2006-01-01

    Near infrared (NIR) reflectance spectroscopy was used to develop a fast determination method for total ginsenosides in Ginseng (Panax Ginseng) powder. The spectra were analyzed with multiplicative signal correction (MSC) correlation method. The best correlative spectra region with the total ginsenosides content was 1660 nm~1880 nm and 2230nm~2380 nm. The NIR calibration models of ginsenosides were built with multiple linear regression (MLR), principle component regression (PCR) and partial least squares (PLS) regression respectively. The results showed that the calibration model built with PLS combined with MSC and the optimal spectrum region was the best one. The correlation coefficient and the root mean square error of correction validation (RMSEC) of the best calibration model were 0.98 and 0.15% respectively. The optimal spectrum region for calibration was 1204nm~2014nm. The result suggested that using NIR to rapidly determinate the total ginsenosides content in ginseng powder were feasible.

  1. Visualization of light propagation in visible Chinese human head for functional near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Li, Ting; Gong, Hui; Luo, Qingming

    2011-04-01

    Using the visible Chinese human data set, which faithfully represents human anatomy, we visualize the light propagation in the head in detail based on Monte Carlo simulation. The simulation is verified to agree with published experimental results in terms of a differential path-length factor. The spatial sensitivity profile turns out to seem like a fat tropical fish with strong distortion along the folding cerebral surface. The sensitive brain region covers the gray matter and extends to the superficial white matter, leading to a large penetration depth (>3 cm). Finally, the optimal source-detector separation is suggested to be narrowed down to 3-3.5 cm, while the sensitivity of the detected signal to brain activation reaches the peak of 8%. These results indicate that the cerebral cortex folding geometry actually has substantial effects on light propagation, which should be necessarily considered for applications of functional near-infrared spectroscopy.

  2. Biodiesel classification by base stock type (vegetable oil) using near infrared spectroscopy data.

    PubMed

    Balabin, Roman M; Safieva, Ravilya Z

    2011-03-18

    The use of biofuels, such as bioethanol or biodiesel, has rapidly increased in the last few years. Near infrared (near-IR, NIR, or NIRS) spectroscopy (>4000cm(-1)) has previously been reported as a cheap and fast alternative for biodiesel quality control when compared with infrared, Raman, or nuclear magnetic resonance (NMR) methods; in addition, NIR can easily be done in real time (on-line). In this proof-of-principle paper, we attempt to find a correlation between the near infrared spectrum of a biodiesel sample and its base stock. This correlation is used to classify fuel samples into 10 groups according to their origin (vegetable oil): sunflower, coconut, palm, soy/soya, cottonseed, castor, Jatropha, etc. Principal component analysis (PCA) is used for outlier detection and dimensionality reduction of the NIR spectral data. Four different multivariate data analysis techniques are used to solve the classification problem, including regularized discriminant analysis (RDA), partial least squares method/projection on latent structures (PLS-DA), K-nearest neighbors (KNN) technique, and support vector machines (SVMs). Classifying biodiesel by feedstock (base stock) type can be successfully solved with modern machine learning techniques and NIR spectroscopy data. KNN and SVM methods were found to be highly effective for biodiesel classification by feedstock oil type. A classification error (E) of less than 5% can be reached using an SVM-based approach. If computational time is an important consideration, the KNN technique (E=6.2%) can be recommended for practical (industrial) implementation. Comparison with gasoline and motor oil data shows the relative simplicity of this methodology for biodiesel classification. PMID:21397073

  3. [Rapid and nondestructive discrimination of hybrid maize seed purity using near infrared spectroscopy].

    PubMed

    Huang, Yan-yan; Zhu, Li-wei; Li, Jun-hui; Wang, Jian-hua; Sun, Bao-qi; Sun, Qun

    2011-03-01

    Near infrared spectroscopy technology was applied to study rapid and nondestructive discrimination method of hybrid maize seed purity. With NongDa108 hybrid seeds and mother 178 seeds, a discrimination model for the purity of maize single seed was built by near infrared reflectance spectroscopy with distinguished partial least squares (DPLS). A total of 200 seeds including 100 hybrid seeds and 100 mother seeds were divided into two groups: calibration set (150 samples) and validation set (50 samples), and each group had same number of hybrid and mother seeds. To eliminate human errors as much as possible we used two sample cups with transmission hole diameter of 3.0 and 4.5 mm, respectively, at the bottom for spectrum acquisition. The location of sample cups and seeds were fixed during spectrum acquisition process. The result showed that the average identification rate with 3 mm transmission hole diameter was 99.82%, significantly higher than that of 4.5 mm whose average identification rate was just 90.96%. There was no significant difference among the identification rates of one replicate and two replicates spectrum on endosperm face, two replicates spectrum on embryo face and four replicates. The rates of validation set reached about 99%, slightly more than that of one replicate on embryo face. The identification rates of one spectrum and two replicates spectrum on endosperm face in calibration and validation set were 100%, with the spectral region between 4000 and 8000 cm(-1). With 3.0 mm transmission hole diameter and 4000-8000 cm(-1) spectral region, the seed purity identification rates in calibration and validation sets built up by one spectrum on endosperm face were 100%. With the increase in principal components, the identification rates in calibration set and validation set gradually increased, and when principal components reached 9, the rate in both of sets were 100%. The results have important value for rapid and nondestructive testing of hybrid maize

  4. [Research on human movement with noninvasive tissue oximeter using near infrared spectroscopy].

    PubMed

    Lin, Hong; Xi, Yu-bao; Yu, Hui

    2014-06-01

    The present paper discusses how to monitor and analyze the relative change in muscle oxygen content in quadriceps tissue, and measures and records the change in blood lactate acid concentration, blood volume and heart rate when eight players who are good at middle-distance races perform grade incremental intensity exercise on cycle ergometer by using noninvasive tissue oximeter with near infrared spectroscopy produced by China independently. The results show that muscle oxygen content has a close relationship (p < 0.01)with exercise load, blood lactic acid, blood volume and heart rate. When determined muscle oxygen content and blood lactate acid concentration was determined for many times to the same person, the test proved regular falling and rising. There was no significant changes when analyzed each set of the data was analyzed through horizontal comparison. It verifies we can judge the subjects's endurable exercise intensity and the upward inflection point of blood lactic acid corresponding to the decreasing inflection point of blood lactate acid concentration & muscle oxygen content according to the muscle oxygen content change of skeletal muscle while exercising. This paper shows NIRS research status and present situation in sports field through investigation, and analyzes the main trouble and research tendency in the future. By understanding NIRS technology gradually, the authors can realize that the muscle oxygen content which measured by noninvasive tissue oximeter using near infrared spectroscopy produced by China independently is a sensitive, nondestructive, up-to-date and reliable index, it has irreplaceable advantages when compared with traditional invasive, excised and fussy test methods. PMID:25358161

  5. Bipolar Mood Tendency and Frontal Activation Using a Multichannel Near Infrared Spectroscopy

    PubMed Central

    Uehara, Toru; Ishige, Yoko

    2015-01-01

    This study aims to examine the association of frontal functioning with subclinical bipolar spectrum by a newly developed convenient method. We investigated subclinical bipolar tendency and frontal lobe activation during word productions using multi-channel near infrared spectroscopy. Participants: 44 healthy university students (mean ages 20.5 years old, and 29 female) gave their written informed consent, and we strictly protected privacy and anonymity was carefully preserved. A 13-items self-report questionnaire (Mood Disorders Questionnaire; MDQ) and a 16-channel near-infrared spectroscopy were used to compare frontal activations between two samples divided by median (4 points) of the total MDQ scores and to analyze correlations between relative changes of cerebral blood volume and bipolarity levels. There was no case suspected as bipolar disorders by MDQ screening (mean 3.4, max 10). Significant differences in lower activations were noted in the right and left pre-frontal cortex (PFC) with higher bipolarity scores using the specific software to analyze the NIRS waveform (P<0.05). Total MDQ were correlated significantly with frontal activation negatively in many channels; therefore, we conducted multiple linear regression to select significant frontal activations using the MDQ as a dependent variable. Stepwise method revealed that activation in left lateral PFC was negatively associated to bipolar tendency, and this regression model was significant (R2=0.10, F=4.5, P=0.04). Differences in frontal functioning suggest that subclinical bipolar tendencies might be related to left lateral PFC activations. It should be confirmed whether the identical pattern can be identified for clinical subjects with bipolar disorders. PMID:26605032

  6. High-Throughput Near-Infrared Reflectance Spectroscopy for Predicting Quantitative and Qualitative Composition Phenotypes of Individual Maize Kernels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Near-infrared reflectance (NIR) spectroscopy can be used for fast and reliable prediction of organic compounds in complex biological samples. We used a recently developed NIR spectroscopy instrument to predict starch, protein, oil, and weight of individual maize (Zea mays) seeds. The starch, prote...

  7. Use of Mid- and Near-Infrared Spectroscopy to Track Degradation of Polyactide Eating Utensils and Containers During Composting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Near-infrared spectroscopy (NIRS) has been used for decades for quantitative analysis of many agricultural products including forages, grains and foods, and more recently has become a powerful tool in the analysis of pharmaceutical ingredients and products. Mid-infrared spectroscopy (MIRS) has been ...

  8. Investigating dehydration from compacts using terahertz pulsed, Raman, and near-infrared spectroscopy.

    PubMed

    Kogermann, Karin; Zeitler, J Axel; Rantanen, Jukka; Rades, Thomas; Taday, Philip F; Pepper, Michael; Heinämäki, Jyrki; Strachan, Clare J

    2007-12-01

    The purpose of this study was to investigate the dehydration of piroxicam monohydrate (PRXMH) in compacts using terahertz pulsed spectroscopy (TPS), Raman spectroscopy, and reflectance near-infrared (NIR) spectroscopy. Compacts were prepared by using PRXMH and poly(tetrafluoro)ethylene powders and combining them in three different manners before compression to produce compacts in which the PRXMH was dispersed throughout the compact, deposited on one face of the compact, or included as a layer within the compact. TPS was a suitable technique to assess the effect of sample preparation on dehydration, whereas Raman and NIR spectroscopy were limited by their sampling depth and the interference of the polymer matrix. TPS revealed that the dehydration behavior depended largely on the compact preparation method. Non-isothermal dehydration was investigated with all three spectroscopic techniques, combined with principal component analysis (PCA) on samples where the PRXMH was deposited on one face of the compact. In addition, variable temperature X-ray powder diffractometry (VT-XRPD) was used to verify the transformation from PRXMH to anhydrous PRX form I, while thermogravimetric analysis (TGA) was used to monitor the water loss. All three spectroscopic techniques allowed in situ monitoring of the dehydration from the surface layers of the compacts. TPS and Raman spectroscopy detected structural changes of the crystal, while NIR spectroscopy was more sensitive to water loss. PCA of the TPS, Raman spectroscopy, and XRPD data revealed similar dehydration profiles. In contrast, the NIR spectroscopy profile was more similar to the TGA results. The spectroscopic techniques were more suitable than slower techniques such as VT-XRPD for monitoring rapid structural changes that occurred during the dehydration. PMID:18198016

  9. Discrimination of tomatoes bred by spaceflight mutagenesis using visible/near infrared spectroscopy and chemometrics

    NASA Astrophysics Data System (ADS)

    Shao, Yongni; Xie, Chuanqi; Jiang, Linjun; Shi, Jiahui; Zhu, Jiajin; He, Yong

    2015-04-01

    Visible/near infrared spectroscopy (Vis/NIR) based on sensitive wavelengths (SWs) and chemometrics was proposed to discriminate different tomatoes bred by spaceflight mutagenesis from their leafs or fruits (green or mature). The tomato breeds were mutant M1, M2 and their parent. Partial least squares (PLS) analysis and least squares-support vector machine (LS-SVM) were implemented for calibration models. PLS analysis was implemented for calibration models with different wavebands including the visible region (400-700 nm) and the near infrared region (700-1000 nm). The best PLS models were achieved in the visible region for the leaf and green fruit samples and in the near infrared region for the mature fruit samples. Furthermore, different latent variables (4-8 LVs for leafs, 5-9 LVs for green fruits, and 4-9 LVs for mature fruits) were used as inputs of LS-SVM to develop the LV-LS-SVM models with the grid search technique and radial basis function (RBF) kernel. The optimal LV-LS-SVM models were achieved with six LVs for the leaf samples, seven LVs for green fruits, and six LVs for mature fruits, respectively, and they outperformed the PLS models. Moreover, independent component analysis (ICA) was executed to select several SWs based on loading weights. The optimal LS-SVM model was achieved with SWs of 550-560 nm, 562-574 nm, 670-680 nm and 705-715 nm for the leaf samples; 548-556 nm, 559-564 nm, 678-685 nm and 962-974 nm for the green fruit samples; and 712-718 nm, 720-729 nm, 968-978 nm and 820-830 nm for the mature fruit samples. All of them had better performance than PLS and LV-LS-SVM, with the parameters of correlation coefficient (rp), root mean square error of prediction (RMSEP) and bias of 0.9792, 0.2632 and 0.0901 based on leaf discrimination, 0.9837, 0.2783 and 0.1758 based on green fruit discrimination, 0.9804, 0.2215 and -0.0035 based on mature fruit discrimination, respectively. The overall results indicated that ICA was an effective way for the

  10. Revised wavelength and spectral response calibrations for AKARI near-infrared grism spectroscopy: Cryogenic phase

    NASA Astrophysics Data System (ADS)

    Baba, Shunsuke; Nakagawa, Takao; Shirahata, Mai; Isobe, Naoki; Usui, Fumihiko; Ohyama, Youichi; Onaka, Takashi; Yano, Kenichi; Kochi, Chihiro

    2016-04-01

    We perform revised spectral calibrations for the AKARI near-infrared grism to correct quantitatively for the effect of the wavelength-dependent refractive index. The near-infrared grism covering the wavelength range of 2.5-5.0 μm, with a spectral resolving power of 120 at 3.6 μm, is found to be contaminated by second-order light at wavelengths longer than 4.9 μm, which is especially serious for red objects. First, we present the wavelength calibration considering the refractive index of the grism as a function of the wavelength for the first time. We find that the previous solution is positively shifted by up to 0.01 μm compared with the revised wavelengths at 2.5-5.0 μm. In addition, we demonstrate that second-order contamination occurs even with a perfect order-sorting filter owing to the wavelength dependence of the refractive index. Secondly, the spectral responses of the system from the first- and second-order light are simultaneously obtained from two types of standard objects with different colors. The response from the second-order light suggests leakage of the order-sorting filter below 2.5 μm. The relations between the output of the detector and the intensities of the first- and second-order light are formalized by a matrix equation that combines the two orders. The removal of the contaminating second-order light can be achieved by solving the matrix equation. The new calibration extends the available spectral coverage of the grism mode from 4.9 μm up to 5.0 μm. The revision can be used to study spectral features falling in these extended wavelengths, e.g., the carbon monoxide fundamental ro-vibrational absorption within nearby active galactic nuclei.

  11. The Earliest Near-infrared Time-series Spectroscopy of a Type Ia Supernova

    NASA Astrophysics Data System (ADS)

    Hsiao, E. Y.; Marion, G. H.; Phillips, M. M.; Burns, C. R.; Winge, C.; Morrell, N.; Contreras, C.; Freedman, W. L.; Kromer, M.; Gall, E. E. E.; Gerardy, C. L.; Höflich, P.; Im, M.; Jeon, Y.; Kirshner, R. P.; Nugent, P. E.; Persson, S. E.; Pignata, G.; Roth, M.; Stanishev, V.; Stritzinger, M.; Suntzeff, N. B.

    2013-04-01

    We present ten medium-resolution, high signal-to-noise ratio near-infrared (NIR) spectra of SN 2011fe from SpeX on the NASA Infrared Telescope Facility (IRTF) and Gemini Near-Infrared Spectrograph (GNIRS) on Gemini North, obtained as part of the Carnegie Supernova Project. This data set constitutes the earliest time-series NIR spectroscopy of a Type Ia supernova (SN Ia), with the first spectrum obtained at 2.58 days past the explosion and covering -14.6 to +17.3 days relative to B-band maximum. C I λ1.0693 μm is detected in SN 2011fe with increasing strength up to maximum light. The delay in the onset of the NIR C I line demonstrates its potential to be an effective tracer of unprocessed material. For the first time in a SN Ia, the early rapid decline of the Mg II λ1.0927 μm velocity was observed, and the subsequent velocity is remarkably constant. The Mg II velocity during this constant phase locates the inner edge of carbon burning and probes the conditions under which the transition from deflagration to detonation occurs. We show that the Mg II velocity does not correlate with the optical light-curve decline rate Δm 15(B). The prominent break at ~1.5 μm is the main source of concern for NIR k-correction calculations. We demonstrate here that the feature has a uniform time evolution among SNe Ia, with the flux ratio across the break strongly correlated with Δm 15(B). The predictability of the strength and the onset of this feature suggests that the associated k-correction uncertainties can be minimized with improved spectral templates.

  12. Single-trial classification of near-infrared spectroscopy signals arising from multiple cortical regions.

    PubMed

    Schudlo, Larissa C; Chau, Tom

    2015-09-01

    Near-infrared spectroscopy (NIRS) brain-computer interface (BCI) studies have primarily made use of measurements taken from a single cortical area. In particular, the anterior prefrontal cortex has been the key area used for detecting higher-level cognitive task performance. However, mental task execution typically requires coordination between several, spatially-distributed brain regions. We investigated the value of expanding the area of interrogation to include NIRS measurements from both the prefrontal and parietal cortices to decode mental states. Hemodynamic activity was monitored at 46 locations over the prefrontal and parietal cortices using a continuous-wave near-infrared spectrometer while 11 able-bodied adults rested or performed either the verbal fluency task (VFT) or Stroop task. Offline classification was performed for the three possible binary problems using 25 iterations of bagging with a linear discriminant base classifier. Classifiers were trained on a 10 dimensional feature set. When all 46 measurement locations were considered for classification, average accuracies of 80.4±7.0%, 82.4±7.6%, and 82.8±5.9% in differentiating VFT vs rest, Stroop vs rest and VFT vs Stroop, respectively, were obtained. Relative to using measurements from the anterior PFC alone, an overall average improvement of 11.3% was achieved. Utilizing NIRS measurements from the prefrontal and parietal cortices can be of value in classifying mental states involving working memory and attention. NIRS-BCI accuracies may be improved by incorporating measurements from several, distinct cortical regions, rather than a single area alone. Further development of an NIRS-BCI supporting combinations of VFT, Stroop task and rest states is also warranted. PMID:25960315

  13. Resolving the coronal line region of NGC 1068 with near-infrared integral field spectroscopy

    NASA Astrophysics Data System (ADS)

    Mazzalay, X.; Rodríguez-Ardila, A.; Komossa, S.; McGregor, Peter J.

    2013-04-01

    We present adaptive optics-assisted J- and K-band integral field spectroscopy of the inner 300 × 300 pc of the Seyfert 2 galaxy NGC 1068. The data were obtained with the Gemini Near-infrared Integral-Field Spectrograph integral field unit spectrometer, which provided us with high-spatial and high-spectral resolution sampling. The wavelength range covered by the observations allowed us to study the [Ca VIII], [Si VI], [Si VII], [Al IX] and [S IX] coronal line (CL) emission, covering ionization potentials up to 328 eV. The observations reveal very rich and complex structures, both in terms of velocity fields and emission-line ratios. The CL emission is elongated along the NE-SW direction, with the stronger emission preferentially localized to the NE of the nucleus. CLs are emitted by gas covering a wide range of velocities, with maximum blueshifts/redshifts of ˜ -1600/1000 km s-1. There is a trend for the gas located on the NE side of the nucleus to be blueshifted while the gas located towards the SW is redshifted. The morphology and the kinematics of the near-infrared CLs are in very good agreement with the ones displayed by low-ionization lines and optical CLs, suggesting a common origin. The line flux distributions, velocity maps, ionization structure (traced by the [Si VII]/[Si VI] emission-line ratio) and low-ionization emission-line ratios (i.e. [Fe II]/Paβ and [Fe II]/[P II]) suggest that the radio jet plays an important role in the structure of the CL region of this object, and possibly in its kinematics.

  14. [Determination of steviol in Stevia Rebaudiana leaves by near infrared spectroscopy].

    PubMed

    Tang, Qi-Kun; Wang, Yul; Wu, Yue-Jin; Min, Di; Chen, Da-Wei; Hu, Tong-Hua

    2014-10-01

    The objective of the present study is to develop a method for rapid determination of the content of stevioside (ST) and rebaudioside A (RA) in Stevia Rebaudiana leaves. One hundred and five samples of stevia from different areas containing ST of 0.27%-1.40% and RA of 0.61%-3.98% were used. The 105 groups' NIRS diagram was processed by different methods including subtracting a straight line (SLS), multiplicative scatter correction (MSC), first derivative (FD), second derivative (SD) and so on, and then all data were analyzed by partial least square (PLS). The study showed that SLS can be used to extracted spectra information thoroughly to analyze the contents of ST, the correlation coefficients of calibration (Re), the root-mean-square errors of calibration (RMSEC) and prediction (RMSEP), and the residual predictive deviation (RPD) were 0.986, 0.341, 1.00 and 2.8, respectively. The correlation coefficients of RA was 0.967, RMSEC was 1.50, RMSEP was 1.98 and RPD was 4.17. The results indicated that near infrared spectroscopy (NIRS) technique offers effective quantitative capability for ST and RA in Stevia Rebaudiana leaves. Then the model of stevia dried leaves was used to compare with the stevia powder near infrared model whose correlation coefficients of ST was 0.986, RMSEC was 0.32, RMSEP was 0.601 and RPD was 2.86 and the correlation coefficients of RA was 0.968, RMSEC was 1.50, RMSEP was 1.48 and RPD was 4.2. The result showed that there was no significant difference between the model of dried leaves and that of the powders. However, the dried leaves NIR model reduces the unnecessary the steps of drying and grinding in the actual detection process, saving the time and reducing the workload. PMID:25739214

  15. THE EARLIEST NEAR-INFRARED TIME-SERIES SPECTROSCOPY OF A TYPE Ia SUPERNOVA

    SciTech Connect

    Hsiao, E. Y.; Phillips, M. M.; Morrell, N.; Contreras, C.; Roth, M.; Marion, G. H.; Kirshner, R. P.; Burns, C. R.; Freedman, W. L.; Persson, S. E.; Winge, C.; Gerardy, C. L.; Hoeflich, P.; Im, M.; Jeon, Y.; Pignata, G.; Stanishev, V.; and others

    2013-04-01

    We present ten medium-resolution, high signal-to-noise ratio near-infrared (NIR) spectra of SN 2011fe from SpeX on the NASA Infrared Telescope Facility (IRTF) and Gemini Near-Infrared Spectrograph (GNIRS) on Gemini North, obtained as part of the Carnegie Supernova Project. This data set constitutes the earliest time-series NIR spectroscopy of a Type Ia supernova (SN Ia), with the first spectrum obtained at 2.58 days past the explosion and covering -14.6 to +17.3 days relative to B-band maximum. C I {lambda}1.0693 {mu}m is detected in SN 2011fe with increasing strength up to maximum light. The delay in the onset of the NIR C I line demonstrates its potential to be an effective tracer of unprocessed material. For the first time in a SN Ia, the early rapid decline of the Mg II {lambda}1.0927 {mu}m velocity was observed, and the subsequent velocity is remarkably constant. The Mg II velocity during this constant phase locates the inner edge of carbon burning and probes the conditions under which the transition from deflagration to detonation occurs. We show that the Mg II velocity does not correlate with the optical light-curve decline rate {Delta}m{sub 15}(B). The prominent break at {approx}1.5 {mu}m is the main source of concern for NIR k-correction calculations. We demonstrate here that the feature has a uniform time evolution among SNe Ia, with the flux ratio across the break strongly correlated with {Delta}m{sub 15}(B). The predictability of the strength and the onset of this feature suggests that the associated k-correction uncertainties can be minimized with improved spectral templates.

  16. Evaluation of chemical components and properties of the jujube fruit using near infrared spectroscopy and chemometrics.

    PubMed

    Guo, Ying; Ni, Yongnian; Kokot, Serge

    2016-01-15

    Near-infrared spectroscopy (NIRS) calibrations were developed for the discrimination of spectra of the jujube (Zizyphus jujuba Mill.) fruit samples from four geographical regions. Prediction models were developed for the quantitative prediction of the contents of jujube fruit, i.e., total sugar, total acid, total phenolic content, and total antioxidant activity. Four pattern recognition methods, principal component analysis (PCA), linear discriminant analysis (LDA), least squares-support vector machines (LS-SVM), and back propagation-artificial neural networks (BP-ANN), were used for the geographical origin classification. Furthermore, three multivariate calibration models based on the standard normal variate (SNV) pretreated NIR spectroscopy, partial least squares (PLS), BP-ANN, and LS-SVM were constructed for quantitative analysis of the four analytes described above. PCA provided a useful qualitative plot of the four types of NIR spectra from the fruit. The LS-SVM model produced best quantitative prediction results. Thus, NIR spectroscopy in conjunction with chemometrics, is a very useful and rapid technique for the discrimination of jujube fruit. PMID:26296251

  17. Variety identification of brown sugar using short-wave near infrared spectroscopy and multivariate calibration

    NASA Astrophysics Data System (ADS)

    Yang, Haiqing; Wu, Di; He, Yong

    2007-11-01

    Near-infrared spectroscopy (NIRS) with the characteristics of high speed, non-destructiveness, high precision and reliable detection data, etc. is a pollution-free, rapid, quantitative and qualitative analysis method. A new approach for variety discrimination of brown sugars using short-wave NIR spectroscopy (800-1050nm) was developed in this work. The relationship between the absorbance spectra and brown sugar varieties was established. The spectral data were compressed by the principal component analysis (PCA). The resulting features can be visualized in principal component (PC) space, which can lead to discovery of structures correlative with the different class of spectral samples. It appears to provide a reasonable variety clustering of brown sugars. The 2-D PCs plot obtained using the first two PCs can be used for the pattern recognition. Least-squares support vector machines (LS-SVM) was applied to solve the multivariate calibration problems in a relatively fast way. The work has shown that short-wave NIR spectroscopy technique is available for the brand identification of brown sugar, and LS-SVM has the better identification ability than PLS when the calibration set is small.

  18. Determination of Hemicellulose, Cellulose and Lignin in Moso Bamboo by Near Infrared Spectroscopy.

    PubMed

    Li, Xiaoli; Sun, Chanjun; Zhou, Binxiong; He, Yong

    2015-01-01

    The contents of hemicellulose, cellulose and lignin are important for moso bamboo processing in biomass energy industry. The feasibility of using near infrared (NIR) spectroscopy for rapid determination of hemicellulose, cellulose and lignin was investigated in this study. Initially, the linear relationship between bamboo components and their NIR spectroscopy was established. Subsequently, successive projections algorithm (SPA) was used to detect characteristic wavelengths for establishing the convenient models. For hemicellulose, cellulose and lignin, 22, 22 and 20 characteristic wavelengths were obtained, respectively. Nonlinear determination models were subsequently built by an artificial neural network (ANN) and a least-squares support vector machine (LS-SVM) based on characteristic wavelengths. The LS-SVM models for predicting hemicellulose, cellulose and lignin all obtained excellent results with high determination coefficients of 0.921, 0.909 and 0.892 respectively. These results demonstrated that NIR spectroscopy combined with SPA-LS-SVM is a useful, nondestructive tool for the determinations of hemicellulose, cellulose and lignin in moso bamboo. PMID:26601657

  19. The Planning Process for Multi-Object Spectroscopy with the JWST Near-Infrared Spectrograph

    NASA Astrophysics Data System (ADS)

    Beck, Tracy L.; Karakla, D. M.; Shyrokov, A.; Pontoppidan, K.; Soderblom, D. R.; Valenti, J. A.; Kassin, S. A.; Gilbert, K.; Blair, W. P.; Muzerolle, J.; Tumlinson, J.; Keyes, C. D.; Pavlovsky, C. M.; LeBlanc, T.

    2014-01-01

    The Near-Infrared Spectrograph (NIRSpec) for the James Webb Space Telescope (JWST) will have a powerful multi-object spectroscopy mode using four configurable Micro-Shutter Arrays (MSAs). The contiguous MSA shutters can be opened to form slits on astronomical targets, for simultaneous spectroscopy of up to 100 sources per exposure. The NIRSpec MSA shutters are in a fixed grid pattern, and careful analysis in the observation planning process will be crucial for optimal definition of science exposures. Our goal is to maximize the number of astronomical science sources observed in the fewest number of MSA slit configurations. We are developing algorithms in the NIRSpec MSA Planning Tool (MPT) to improve the quality of planned observations using several common science observing strategies as test use cases. For example, the needs for planning extremely deep exposures on a small number of JWST discovered z > 10 galaxy candidates will differ significantly from the requirements for planning spectral observations on a representative sample of stars from a galactic star cluster catalog. In this poster, we present a high level overview of our plans to develop and optimize the MPT for the JWST NIRSpec multi-object spectroscopy mode.

  20. Evaluation of chemical components and properties of the jujube fruit using near infrared spectroscopy and chemometrics

    NASA Astrophysics Data System (ADS)

    Guo, Ying; Ni, Yongnian; Kokot, Serge

    2016-01-01

    Near-infrared spectroscopy (NIRS) calibrations were developed for the discrimination of spectra of the jujube (Zizyphus jujuba Mill.) fruit samples from four geographical regions. Prediction models were developed for the quantitative prediction of the contents of jujube fruit, i.e., total sugar, total acid, total phenolic content, and total antioxidant activity. Four pattern recognition methods, principal component analysis (PCA), linear discriminant analysis (LDA), least squares-support vector machines (LS-SVM), and back propagation-artificial neural networks (BP-ANN), were used for the geographical origin classification. Furthermore, three multivariate calibration models based on the standard normal variate (SNV) pretreated NIR spectroscopy, partial least squares (PLS), BP-ANN, and LS-SVM were constructed for quantitative analysis of the four analytes described above. PCA provided a useful qualitative plot of the four types of NIR spectra from the fruit. The LS-SVM model produced best quantitative prediction results. Thus, NIR spectroscopy in conjunction with chemometrics, is a very useful and rapid technique for the discrimination of jujube fruit.

  1. Intraoperative near-infrared fluorescence imaging and spectroscopy identifies residual tumor cells in wounds

    PubMed Central

    Holt, David; Parthasarathy, Ashwin B.; Okusanya, Olugbenga; Keating, Jane; Venegas, Ollin; Deshpande, Charuhas; Karakousis, Giorgos; Madajewski, Brian; Durham, Amy; Nie, Shuming; Yodh, Arjun G.; Singhal, Sunil

    2015-01-01

    Abstract. Surgery is the most effective method to cure patients with solid tumors, and 50% of all cancer patients undergo resection. Local recurrences are due to tumor cells remaining in the wound, thus we explore near-infrared (NIR) fluorescence spectroscopy and imaging to identify residual cancer cells after surgery. Fifteen canines and two human patients with spontaneously occurring sarcomas underwent intraoperative imaging. During the operation, the wounds were interrogated with NIR fluorescence imaging and spectroscopy. NIR monitoring identified the presence or absence of residual tumor cells after surgery in 14/15 canines with a mean fluorescence signal-to-background ratio (SBR) of ∼16. Ten animals showed no residual tumor cells in the wound bed (mean SBR<2, P<0.001). None had a local recurrence at >1-year follow-up. In five animals, the mean SBR of the wound was >15, and histopathology confirmed tumor cells in the postsurgical wound in four/five canines. In the human pilot study, neither patient had residual tumor cells in the wound bed, and both remain disease free at >1.5-year follow up. Intraoperative NIR fluorescence imaging and spectroscopy identifies residual tumor cells in surgical wounds. These observations suggest that NIR imaging techniques may improve tumor resection during cancer operations. PMID:26160347

  2. Determination of amino acids in Chinese rice wine by fourier transform near-infrared spectroscopy.

    PubMed

    Shen, Fei; Niu, Xiaoying; Yang, Danting; Ying, Yibin; Li, Bobin; Zhu, Geqing; Wu, Jian

    2010-09-01

    Chinese rice wine is abundant in amino acids. The possibility of quantitative detection of 16 free amino acids (aspartic acid, threonine, serine, glutamic acid, proline, glycine, alanine, valine, methionine, isoleucine, leucine, tyrosine, phenylalanine, lysine, histidine, and arginine) in Chinese rice wine by Fourier transform near-infrared (NIR) spectroscopy was investigated for the first time in this study. A total of 98 samples from vintage 2007 rice wines with different aging times were analyzed by NIR spectroscopy in transmission mode. Calibration models were developed using partial least-squares regression (PLSR) with high-performance liquid chromatography (HPLC) by postcolumn derivatization and diode array detection as a reference method. To validate the calibration models, full cross (leave-one-out) validation was employed. The results showed that the calibration statistics were good (rcal>0.94) for all amino acids except proline, histidine, and arginine. The correlation coefficient in cross validation (rcv) was >0.81 for 12 amino acids. The residual predictive deviation (RPD) value obtained was >1.5 in all amino acids except proline and arginine, and it was >2.0 in 6 amino acids. The results obtained in this study indicated that NIR spectroscopy could be used as an easy, rapid, and novel tool to quantitatively predict free amino acids in Chinese rice wine without sophisticated methods. PMID:20707307

  3. Determination of Hemicellulose, Cellulose and Lignin in Moso Bamboo by Near Infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Li, Xiaoli; Sun, Chanjun; Zhou, Binxiong; He, Yong

    2015-11-01

    The contents of hemicellulose, cellulose and lignin are important for moso bamboo processing in biomass energy industry. The feasibility of using near infrared (NIR) spectroscopy for rapid determination of hemicellulose, cellulose and lignin was investigated in this study. Initially, the linear relationship between bamboo components and their NIR spectroscopy was established. Subsequently, successive projections algorithm (SPA) was used to detect characteristic wavelengths for establishing the convenient models. For hemicellulose, cellulose and lignin, 22, 22 and 20 characteristic wavelengths were obtained, respectively. Nonlinear determination models were subsequently built by an artificial neural network (ANN) and a least-squares support vector machine (LS-SVM) based on characteristic wavelengths. The LS-SVM models for predicting hemicellulose, cellulose and lignin all obtained excellent results with high determination coefficients of 0.921, 0.909 and 0.892 respectively. These results demonstrated that NIR spectroscopy combined with SPA-LS-SVM is a useful, nondestructive tool for the determinations of hemicellulose, cellulose and lignin in moso bamboo.

  4. Correlation between near infrared spectroscopy and electrical techniques in measuring skin moisture content

    NASA Astrophysics Data System (ADS)

    Mohamad, M.; Sabbri, A. R. M.; Mat Jafri, M. Z.; Omar, A. F.

    2014-11-01

    Near infrared (NIR) spectroscopy technique serves as an important tool for the measurement of moisture content of skin owing to the advantages it has over the other techniques. The purpose of the study is to develop a correlation between NIR spectrometer with electrical conventional techniques for skin moisture measurement. A non-invasive measurement of moisture content of skin was performed on different part of human face and hand under control environment (temperature 21 ± 1 °C, relative humidity 45 ± 5 %). Ten healthy volunteers age between 21-25 (male and female) participated in this study. The moisture content of skin was measured using DermaLab® USB Moisture Module, Scalar Moisture Checker and NIR spectroscopy (NIRQuest). Higher correlation was observed between NIRQuest and Dermalab moisture probe with a coefficient of determination (R2) above 70 % for all the subjects. However, the value of R2 between NIRQuest and Moisture Checker was observed to be lower with the R2 values ranges from 51.6 to 94.4 %. The correlation of NIR spectroscopy technique successfully developed for measuring moisture content of the skin. The analysis of this correlation can help to establish novel instruments based on an optical system in clinical used especially in the dermatology field.

  5. Intraoperative near-infrared fluorescence imaging and spectroscopy identifies residual tumor cells in wounds

    NASA Astrophysics Data System (ADS)

    Holt, David; Parthasarathy, Ashwin B.; Okusanya, Olugbenga; Keating, Jane; Venegas, Ollin; Deshpande, Charuhas; Karakousis, Giorgos; Madajewski, Brian; Durham, Amy; Nie, Shuming; Yodh, Arjun G.; Singhal, Sunil

    2015-07-01

    Surgery is the most effective method to cure patients with solid tumors, and 50% of all cancer patients undergo resection. Local recurrences are due to tumor cells remaining in the wound, thus we explore near-infrared (NIR) fluorescence spectroscopy and imaging to identify residual cancer cells after surgery. Fifteen canines and two human patients with spontaneously occurring sarcomas underwent intraoperative imaging. During the operation, the wounds were interrogated with NIR fluorescence imaging and spectroscopy. NIR monitoring identified the presence or absence of residual tumor cells after surgery in 14/15 canines with a mean fluorescence signal-to-background ratio (SBR) of ˜16. Ten animals showed no residual tumor cells in the wound bed (mean SBR<2, P<0.001). None had a local recurrence at >1-year follow-up. In five animals, the mean SBR of the wound was >15, and histopathology confirmed tumor cells in the postsurgical wound in four/five canines. In the human pilot study, neither patient had residual tumor cells in the wound bed, and both remain disease free at >1.5-year follow up. Intraoperative NIR fluorescence imaging and spectroscopy identifies residual tumor cells in surgical wounds. These observations suggest that NIR imaging techniques may improve tumor resection during cancer operations.

  6. Investigation of the composition of anabolic tablets using near infrared spectroscopy and Raman chemical imaging.

    PubMed

    Rebiere, Hervé; Ghyselinck, Céline; Lempereur, Laurent; Brenier, Charlotte

    2016-03-01

    The use of performance enhancing drugs is a widespread phenomenon in professional and leisure sports. A spectroscopic study was carried out on anabolic tablets labelled as 5 mg methandienone tablets provided by police departments. The analytical approach was based on a two-step methodology: a fast analysis of tablets using near infrared (NIR) spectroscopy to assess sample homogeneity based on their global composition, followed by Raman chemical imaging of one sample per NIR profile to obtain information on sample formulation. NIR spectroscopy assisted by a principal components analysis (PCA) enabled fast discrimination of different profiles based on the excipient formulation. Raman hyperspectral imaging and multivariate curve resolution - alternating least square (MCR-ALS) provided chemical images of the distribution of the active substance and excipients within tablets and facilitated identification of the active compounds. The combination of NIR spectroscopy and Raman chemical imaging highlighted dose-to-dose variations and succeeded in the discrimination of four different formulations out of eight similar samples of anabolic tablets. Some samples contained either methandienone or methyltestosterone whereas one sample did not contain an active substance. Other ingredients were sucrose, lactose, starch or talc. Both techniques were fast and non-destructive and therefore can be carried out as exploratory methods prior to destructive screening methods. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26198290

  7. Intraoperative near-infrared fluorescence imaging and spectroscopy identifies residual tumor cells in wounds.

    PubMed

    Holt, David; Parthasarathy, Ashwin B; Okusanya, Olugbenga; Keating, Jane; Venegas, Ollin; Deshpande, Charuhas; Karakousis, Giorgos; Madajewski, Brian; Durham, Amy; Nie, Shuming; Yodh, Arjun G; Singhal, Sunil

    2015-07-01

    Surgery is the most effective method to cure patients with solid tumors, and 50% of all cancer patients undergo resection. Local recurrences are due to tumor cells remaining in the wound, thus we explore near-infrared (NIR) fluorescence spectroscopy and imaging to identify residual cancer cells after surgery. Fifteen canines and two human patients with spontaneously occurring sarcomas underwent intraoperative imaging. During the operation, the wounds were interrogated with NIR fluorescence imaging and spectroscopy. NIR monitoring identified the presence or absence of residual tumor cells after surgery in 14/15 canines with a mean fluorescence signal-to-background ratio (SBR) of ∼16 . Ten animals showed no residual tumor cells in the wound bed (mean SBR<2 , P<0.001 ). None had a local recurrence at >1-year follow-up. In five animals, the mean SBR of the wound was >15 , and histopathology confirmed tumor cells in the postsurgical wound in four/five canines. In the human pilot study, neither patient had residual tumor cells in the wound bed, and both remain disease free at >1.5-year follow up. Intraoperative NIR fluorescence imaging and spectroscopy identifies residual tumor cells in surgical wounds. These observations suggest that NIR imaging techniques may improve tumor resection during cancer operations. PMID:26160347

  8. Models for Estimating the Physical Properties of Paddy Soil Using Visible and Near Infrared Reflectance Spectroscopy

    NASA Astrophysics Data System (ADS)

    Gholizadeh, A.; Amin, M. S. M.; Borůvka, L.; Saberioon, M. M.

    2014-07-01

    A fast and convenient soil analytical technique is needed for soil quality assessment and precision soil management. The main objective of this study was to evaluate the ability of visible (Vis) and near-infrared (NIR) refl ectance spectroscopy to predict paddy soil properties in a typical Malaysian paddy fi eld. To assess the utility of spectroscopy for soil physical characteristics (bulk density, moisture content, clay, silt and sand) prediction, 118 soil samples were used for laboratory analysis and optical measurement in the Vis-NIR region using an analytical spectral device (ASD) FieldSpec spectroradiometer (350-2500 nm). The Savitzky-Golay algorithm and stepwise multiple linear regression (SMLR) were then applied to preprocess, model, and predict the properties on the basis of their spectral refl ectance within the Vis-NIR range. One-third of the samples (40 samples) were withheld for validation purposes. The study revealed that Vis and NIR spectroscopy calibration models for all the measured soil physical characteristics provided a good fi t (R2 > 0.78); hence Vis and NIR (specifi cally NIR refl ectance) can be considered to be a reliable tool to assess soil physical properties of Malaysian paddy fi elds. The results of this study could contribute signifi cantly to developing site-specifi c management.

  9. Combined Cerebral and Renal Near-Infrared Spectroscopy After Congenital Heart Surgery.

    PubMed

    Gil-Anton, Javier; Redondo, Silvia; Garcia Urabayen, Diego; Nieto Faza, Manuel; Sanz, Irene; Pilar, Javier

    2015-08-01

    The maintenance of an adequate oxygen supply to tissues after congenital heart surgery is essential for good outcomes. The objective of this study was to assess the usefulness of near-infrared spectroscopy (NIRS) for estimating central venous oxygen saturation (ScvO2) using both cerebral and renal measurements, explore its relation with cardiac output measurements and check its ability to detect low cardiac output. A prospective observational pilot study was conducted in patients weighing <10 kg undergoing cardiopulmonary bypass surgery. Spectroscopy probes were placed on the forehead and renal area, and serial cardiac output measurements were obtained by femoral transpulmonary thermodilution over the first 24 h after surgery. In the 15 patients studied, ScvO2 was correlated with cerebral (r = 0.58), renal (r = 0.60) and combined (r = 0.71) measurements. Likewise, the systolic index was correlated with the NIRS signals: cerebral (r = 0.60), renal (r = 0.50) and combined (r = 0.66). Statistically significant differences were found in the NIRS measures registered in the 29 low cardiac output events detected by thermodilution: cerebral: 62 % (59-65) versus 69 % (63-76); renal: 83 % (70-89) versus 89 % (83-95); and combined 64 % (60-69) versus 72 % (67-76). In our series, combined cerebral and renal monitoring was correlated with central venous oxygen saturation and cardiac output; low cardiac output detection associated a different spectroscopy pattern. PMID:25764508

  10. Diagnosis of colorectal cancer by near-infrared optical fiber spectroscopy and random forest

    NASA Astrophysics Data System (ADS)

    Chen, Hui; Lin, Zan; Wu, Hegang; Wang, Li; Wu, Tong; Tan, Chao

    2015-01-01

    Near-infrared (NIR) spectroscopy has such advantages as being noninvasive, fast, relatively inexpensive, and no risk of ionizing radiation. Differences in the NIR signals can reflect many physiological changes, which are in turn associated with such factors as vascularization, cellularity, oxygen consumption, or remodeling. NIR spectral differences between colorectal cancer and healthy tissues were investigated. A Fourier transform NIR spectroscopy instrument equipped with a fiber-optic probe was used to mimic in situ clinical measurements. A total of 186 spectra were collected and then underwent the preprocessing of standard normalize variate (SNV) for removing unwanted background variances. All the specimen and spots used for spectral collection were confirmed staining and examination by an experienced pathologist so as to ensure the representative of the pathology. Principal component analysis (PCA) was used to uncover the possible clustering. Several methods including random forest (RF), partial least squares-discriminant analysis (PLSDA), K-nearest neighbor and classification and regression tree (CART) were used to extract spectral features and to construct the diagnostic models. By comparison, it reveals that, even if no obvious difference of misclassified ratio (MCR) was observed between these models, RF is preferable since it is quicker, more convenient and insensitive to over-fitting. The results indicate that NIR spectroscopy coupled with RF model can serve as a potential tool for discriminating the colorectal cancer tissues from normal ones.

  11. Determination of Hemicellulose, Cellulose and Lignin in Moso Bamboo by Near Infrared Spectroscopy

    PubMed Central

    Li, Xiaoli; Sun, Chanjun; Zhou, Binxiong; He, Yong

    2015-01-01

    The contents of hemicellulose, cellulose and lignin are important for moso bamboo processing in biomass energy industry. The feasibility of using near infrared (NIR) spectroscopy for rapid determination of hemicellulose, cellulose and lignin was investigated in this study. Initially, the linear relationship between bamboo components and their NIR spectroscopy was established. Subsequently, successive projections algorithm (SPA) was used to detect characteristic wavelengths for establishing the convenient models. For hemicellulose, cellulose and lignin, 22, 22 and 20 characteristic wavelengths were obtained, respectively. Nonlinear determination models were subsequently built by an artificial neural network (ANN) and a least-squares support vector machine (LS-SVM) based on characteristic wavelengths. The LS-SVM models for predicting hemicellulose, cellulose and lignin all obtained excellent results with high determination coefficients of 0.921, 0.909 and 0.892 respectively. These results demonstrated that NIR spectroscopy combined with SPA-LS-SVM is a useful, nondestructive tool for the determinations of hemicellulose, cellulose and lignin in moso bamboo. PMID:26601657

  12. Image-guided near infrared spectroscopy using boundary element method: phantom validation

    PubMed Central

    Srinivasan, Subhadra; Carpenter, Colin; Pogue, Brian W.; Paulsen, Keith D.

    2010-01-01

    Image-guided near infrared spectroscopy (IG-NIRS) can provide high-resolution vascular, metabolic and molecular characterization of localized tissue volumes in-vivo. The approach for IG-NIRS uses hybrid systems where the spatial anatomical structure of tissue obtained from standard imaging modalities (such as MRI) is combined with tissue information from diffuse optical imaging spectroscopy. There is need to optimize these hybrid systems for large-scale clinical trials anticipated in the near future in order to evaluate the feasibility of this technology across a larger population. However, existing computational methods such as the finite element method mesh arbitrary image volumes, which inhibit automation, especially with large numbers of datasets. Circumventing this issue, a boundary element method (BEM) for IG-NIRS systems in 3–D is presented here using only surface rendering and discretization. The process of surface creation and meshing is faster, more reliable, and is easily generated automatically as compared to full volume meshing. The proposed method has been implemented here for multi-spectral non-invasive characterization of tissue. In phantom experiments, 3–D spectral BEM-based spectroscopy recovered the oxygen dissociation curve with mean error of 6.6% and tracked variation in total hemoglobin linearly. PMID:20445830

  13. Prefrontal cortex activation during story encoding/retrieval: a multi-channel functional near-infrared spectroscopy study

    PubMed Central

    Basso Moro, Sara; Cutini, Simone; Ursini, Maria Laura; Ferrari, Marco; Quaresima, Valentina

    2013-01-01

    Encoding, storage and retrieval constitute three fundamental stages in information processing and memory. They allow for the creation of new memory traces, the maintenance and the consolidation of these traces over time, and the access and recover of the stored information from short or long-term memory. Functional near-infrared spectroscopy (fNIRS) is a non-invasive neuroimaging technique that measures concentration changes of oxygenated-hemoglobin (O2Hb) and deoxygenated-hemoglobin (HHb) in cortical microcirculation blood vessels by means of the characteristic absorption spectra of hemoglobin in the near-infrared range. In the present study, we monitored, using a 16-channel fNIRS system, the hemodynamic response during the encoding and retrieval processes (EP and RP, respectively) over the prefrontal cortex (PFC) of 13 healthy subjects (27.2 ± 2.6 years) while were performing the “Logical Memory Test” (LMT) of the Wechsler Memory Scale. A LMT-related PFC activation was expected; specifically, it was hypothesized a neural dissociation between EP and RP. The results showed a heterogeneous O2Hb/HHb response over the mapped area during the EP and the RP, with a O2Hb progressive and prominent increment in ventrolateral PFC (VLPFC) since the beginning of the EP. During the RP a broader activation, including the VLPFC, the dorsolateral PFC and the frontopolar cortex, was observed. This could be explained by the different contributions of the PFC regions in the EP and the RP. Considering the fNIRS applicability for the hemodynamic monitoring during the LMT performance, this study has demonstrated that fNIRS could be utilized as a valuable clinical diagnostic tool, and that it has the potential to be adopted in patients with cognitive disorders or slight working memory deficits. PMID:24427131

  14. Prefrontal cortex activation during story encoding/retrieval: a multi-channel functional near-infrared spectroscopy study.

    PubMed

    Basso Moro, Sara; Cutini, Simone; Ursini, Maria Laura; Ferrari, Marco; Quaresima, Valentina

    2013-01-01

    Encoding, storage and retrieval constitute three fundamental stages in information processing and memory. They allow for the creation of new memory traces, the maintenance and the consolidation of these traces over time, and the access and recover of the stored information from short or long-term memory. Functional near-infrared spectroscopy (fNIRS) is a non-invasive neuroimaging technique that measures concentration changes of oxygenated-hemoglobin (O2Hb) and deoxygenated-hemoglobin (HHb) in cortical microcirculation blood vessels by means of the characteristic absorption spectra of hemoglobin in the near-infrared range. In the present study, we monitored, using a 16-channel fNIRS system, the hemodynamic response during the encoding and retrieval processes (EP and RP, respectively) over the prefrontal cortex (PFC) of 13 healthy subjects (27.2 ± 2.6 years) while were performing the "Logical Memory Test" (LMT) of the Wechsler Memory Scale. A LMT-related PFC activation was expected; specifically, it was hypothesized a neural dissociation between EP and RP. The results showed a heterogeneous O2Hb/HHb response over the mapped area during the EP and the RP, with a O2Hb progressive and prominent increment in ventrolateral PFC (VLPFC) since the beginning of the EP. During the RP a broader activation, including the VLPFC, the dorsolateral PFC and the frontopolar cortex, was observed. This could be explained by the different contributions of the PFC regions in the EP and the RP. Considering the fNIRS applicability for the hemodynamic monitoring during the LMT performance, this study has demonstrated that fNIRS could be utilized as a valuable clinical diagnostic tool, and that it has the potential to be adopted in patients with cognitive disorders or slight working memory deficits. PMID:24427131

  15. Arc welding quality monitoring by means of near infrared imaging spectroscopy

    NASA Astrophysics Data System (ADS)

    Garcia-Allende, P. B.; Mirapeix, J.; Cobo, A.; Conde, O. M.; Lopez-Higuera, J. M.

    2008-03-01

    The search for an efficient on-line monitoring system focused on the real-time analysis of the welding quality is an active area of research, mainly due to the widespread use of both arc and laser welding processes in relevant industrial scenarios such as aeronautics or nuclear. In this work, an improvement in the performance of a previously designed monitor system is presented. This improvement is accomplished by the employment of a dual spatial-spectral technique, namely imaging spectroscopy. This technique allows the simultaneous determination of the optical spectrum components and the spatial location of an object in a surface. In this way, the spatially characterization of the plasma emitted during a tungsten inert gas (TIG) welding is performed. The main advantage of this technique is that the spectra of all the points in the line of vision are measured at the same time. Not only are all the spectra captured simultaneously, but they are also processed as a batch, allowing the investigation of the welding quality. Moreover, imaging spectroscopy provides the desired real-time operation. To simultaneously acquire the information of both domains, spectral and spatial, a passive Prism-Grating-Prism (PGP) device can be used. In this paper the plasma spectra is captured during the welding test by means of a near infrared imaging spectroscopic system which consists of input optics, an imaging spectrograph and a monochrome camera. Technique features regarding on-line welding quality monitoring are discussed by means of several experimental welding tests.

  16. Discrimination between authentic and adulterated liquors by near-infrared spectroscopy and ensemble classification

    NASA Astrophysics Data System (ADS)

    Chen, Hui; Tan, Chao; Wu, Tong; Wang, Li; Zhu, Wanping

    2014-09-01

    Chinese liquor is one of the famous distilled spirits and counterfeit liquor is becoming a serious problem in the market. Especially, age liquor is facing the crisis of confidence because it is difficult for consumer to identify the marked age, which prompts unscrupulous traders to pose off low-grade liquors as high-grade liquors. An ideal method for authenticity confirmation of liquors should be non-invasive, non-destructive and timely. The combination of near-infrared spectroscopy with chemometrics proves to be a good way to reach these premises. A new strategy is proposed for classification and verification of the adulteration of liquors by using NIR spectroscopy and chemometric classification, i.e., ensemble support vector machines (SVM). Three measures, i.e., accuracy, sensitivity and specificity were used for performance evaluation. The results confirmed that the strategy can serve as a screening tool applied to verify adulteration of the liquor, that is, a prior step used to condition the sample to a deeper analysis only when a positive result for adulteration is obtained by the proposed methodology.

  17. Detection of urinary estrogen conjugates and creatinine using near infrared spectroscopy in Bornean orangutans (Pongo Pygmaeus).

    PubMed

    Kinoshita, Kodzue; Kuze, Noko; Kobayashi, Toshio; Miyakawa, Etsuko; Narita, Hiromitsu; Inoue-Murayama, Miho; Idani, Gen'ichi; Tsenkova, Roumiana

    2016-01-01

    For promoting in situ conservation, it is important to estimate the density distribution of fertile individuals, and there is a need for developing an easy monitoring method to discriminate between physiological states. To date, physiological state has generally been determined by measuring hormone concentration using radioimmunoassay or enzyme immunoassay (EIA) methods. However, these methods have rarely been applied in situ because of the requirements for a large amount of reagent, instruments, and a radioactive isotope. In addition, the proper storage of the sample (including urine and feces) on site until analysis is difficult. On the other hand, near infrared (NIR) spectroscopy requires no reagent and enables rapid measurement. In the present study, we attempted urinary NIR spectroscopy to determine the estrogen levels of orangutans in Japanese zoos and in the Danum Valley Conservation Area, Sabah, Malaysia. Reflectance NIR spectra were obtained from urine stored using a filter paper. Filter paper is easy to use to store dried urine, even in the wild. Urinary estrogen and creatinine concentrations measured by EIA were used as the reference data of partial least square (PLS) regression of urinary NIR spectra. High accuracies (R(2) > 0.68) were obtained in both estrogen and creatinine regression models. In addition, the PLS regressions in both standards showed higher accuracies (R(2) > 0.70). Therefore, the present study demonstrates that urinary NIR spectra have the potential to estimate the estrogen and creatinine concentrations. PMID:26561334

  18. On-line prediction of beef quality traits using near infrared spectroscopy.

    PubMed

    De Marchi, Massimo

    2013-08-01

    The aim of this study was to test the ability of visible-near infrared (Vis-NIR) reflectance spectroscopy to predict beef quality traits in the slaughterhouse by directly applying a fiber-optic probe on the carcass surface. Carcasses from 230 young bulls and heifers slaughtered in two commercial abattoirs were included in the experiment. Vis-NIR spectra were recorded on an exposed surface of M. gracilis in the abattoirs 4 to 6 and 14 to 16 h post mortem. Traits evaluated were pH, color indexes (L*, a*, b*, H, and SI), cooking loss, and Warner-Bratzler shear force. Prediction models were satisfactory for pH and color indexes, and promising for cooking loss but not for Warner-Bratzler shear force. Results of this work show that Vis-NIR spectroscopy may be a useful tool for on-line prediction of some physical beef quality traits when applied directly on the carcass surface. PMID:23618741

  19. Visible and near-infrared spectroscopy analysis of a polycyclic aromatic hydrocarbon in soils.

    PubMed

    Okparanma, Reuben N; Mouazen, Abdul M

    2013-01-01

    Visible and near-infrared (VisNIR) spectroscopy is becoming recognised by soil scientists as a rapid and cost-effective measurement method for hydrocarbons in petroleum-contaminated soils. This study investigated the potential application of VisNIR spectroscopy (350-2500 nm) for the prediction of phenanthrene, a polycyclic aromatic hydrocarbon (PAH), in soils. A total of 150 diesel-contaminated soil samples were used in the investigation. Partial least-squares (PLS) regression analysis with full cross-validation was used to develop models to predict the PAH compound. Results showed that the PAH compound was predicted well with residual prediction deviation of 2.0-2.32, root-mean-square error of prediction of 0.21-0.25 mg kg(-1), and coefficient of determination (r (2)) of 0.75-0.83. The mechanism of prediction was attributed to covariation of the PAH with clay and soil organic carbon. Overall, the results demonstrated that the methodology may be used for predicting phenanthrene in soils utilizing the interrelationship between clay and soil organic carbon. PMID:24453798

  20. Non-destructive detection of pesticide residues in cucumber using visible/near-infrared spectroscopy.

    PubMed

    Jamshidi, Bahareh; Mohajerani, Ezeddin; Jamshidi, Jamshid; Minaei, Saeid; Sharifi, Ahmad

    2015-01-01

    The feasibility of using visible/near-infrared (Vis/NIR) spectroscopy was assessed for non-destructive detection of diazinon residues in intact cucumbers. Vis/NIR spectra of diazinon solution and cucumber samples without and with different concentrations of diazinon residue were analysed at the range of 450-1000 nm. Partial least squares-discriminant analysis (PLS-DA) models were developed based on different spectral pre-processing techniques to classify cucumbers with contents of diazinon below and above the MRL as safe and unsafe samples, respectively. The best model was obtained using a first-derivative method with the lowest standard error of cross-validation (SECV = 0.366). Moreover, total percentages of correctly classified samples in calibration and prediction sets were 97.5% and 92.31%, respectively. It was concluded that Vis/NIR spectroscopy could be an appropriate, fast and non-destructive technology for safety control of intact cucumbers by the absence/presence of diazinon residues. PMID:25789964

  1. Cure Monitoring of an Unsaturated Polyester Resin Using Near-Infrared and Fluorescence Spectroscopies

    NASA Astrophysics Data System (ADS)

    Sung, Chong S. P.; Grunden, Bradley L.

    1998-03-01

    The applicability of both near-infrared (NIR) and fluorescence spectroscopy for the purpose of cure monitoring an unsaturated polyester (UPE) resin was investigated. Based on standard reference mixtures, peak assignments in the NIR region of the spectrum were made. It was determined that the peak at 1629 nm was due to the first overtone band of RHC=CH2 stretching modes in styrene, while a combination of RHC=CHR and -C=C- stretching modes in diethyl fumarate were responsible for the peak observed at 2087 nm. NIR spectra of the UPE resin during isothermal cure at 75 C exhibited decreases in peak absorbance at 1629 and 2087 nm due to conversion of styrene and vinylene bonds, respectively. Conversion of styrene and vinylene with time calculated using NIR spectra showed similar trends found with FTIR analysis throughout the entire conversion range. Fluorescence spectroscopy was used to monitor the isothermal curing reaction of the UPE resin by exciting styrene at 250 nm. Emission intensity at ca. 306 nm remained unchanged for the initial 60-80 minutes then increased with cure time due to a reduced self-quenching effect as cure proceeded. The increase in fluorescence intensity was concurrent with an increase in styrene conversion up to 93% styrene conversion.

  2. Classification of diabetes and measurement of blood glucose concentration noninvasively using near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Li, Zhe; Li, Gang; Yan, Wen-Juan; Lin, Ling

    2014-11-01

    Developing noninvasive blood glucose monitoring method is an to immense need to alleviate the pain and suffering of diabetics associated with the frequent pricking of skin for taking blood sample. A hybrid algorithm for multivariate calibration is proposed to improve the prediction performance of classification of diabetes and measurement of blood glucose concentration by near infrared (NIR) spectroscopy noninvasively. The algorithm is based on wavelet prism modified uninformative variable elimination approach (WP-mUVE) combined with least squares support vector machine (LSSVM), named as WP-mUVE-LSSVM. The method is successfully applied to diabetic classification experiment (in vivo) and blood glucose concentration measurement experiment (in vivo) respectively. Human tongue is selected as the measuring site in this study. To evaluate effectiveness of pretreatment method and quality of calibration models, several usually used pretreatment methods and kernel functions of LSSVM are introduced comparing with our method. Higher quality data is obtained by our pretreatment method owing to the elimination of varying background and noise of spectra data simultaneously. Better prediction accuracy and adaptability are obtained by LSSVM model with radial basis kernel function. The results indicate that WP-mUVE-LSSVM holds promise for the classification of diabetes and measurement of blood glucose concentration noninvasively based on human tongue using NIR spectroscopy.

  3. Nondestructive evaluation of soluble solid content in strawberry by near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Guo, Zhiming; Huang, Wenqian; Chen, Liping; Wang, Xiu; Peng, Yankun

    This paper indicates the feasibility to use near infrared (NIR) spectroscopy combined with synergy interval partial least squares (siPLS) algorithms as a rapid nondestructive method to estimate the soluble solid content (SSC) in strawberry. Spectral preprocessing methods were optimized selected by cross-validation in the model calibration. Partial least squares (PLS) algorithm was conducted on the calibration of regression model. The performance of the final model was back-evaluated according to root mean square error of calibration (RMSEC) and correlation coefficient (R2 c) in calibration set, and tested by mean square error of prediction (RMSEP) and correlation coefficient (R2 p) in prediction set. The optimal siPLS model was obtained with after first derivation spectra preprocessing. The measurement results of best model were achieved as follow: RMSEC = 0.2259, R2 c = 0.9590 in the calibration set; and RMSEP = 0.2892, R2 p = 0.9390 in the prediction set. This work demonstrated that NIR spectroscopy and siPLS with efficient spectral preprocessing is a useful tool for nondestructively evaluation SSC in strawberry.

  4. Near-Infrared Spectroscopy as a Diagnostic Tool for Distinguishing between Normal and Malignant Colorectal Tissues

    PubMed Central

    Chen, Hui; Lin, Zan; Mo, Lin; Wu, Tong; Tan, Chao

    2015-01-01

    Cancer diagnosis is one of the most important tasks of biomedical research and has become the main objective of medical investigations. The present paper proposed an analytical strategy for distinguishing between normal and malignant colorectal tissues by combining the use of near-infrared (NIR) spectroscopy with chemometrics. The successive projection algorithm-linear discriminant analysis (SPA-LDA) was used to seek a reduced subset of variables/wavenumbers and build a diagnostic model of LDA. For comparison, the partial least squares-discriminant analysis (PLS-DA) based on full-spectrum classification was also used as the reference. Principal component analysis (PCA) was used for a preliminary analysis. A total of 186 spectra from 20 patients with partial colorectal resection were collected and divided into three subsets for training, optimizing, and testing the model. The results showed that, compared to PLS-DA, SPA-LDA provided more parsimonious model using only three wavenumbers/variables (4065, 4173, and 5758 cm−1) to achieve the sensitivity of 84.6%, 92.3%, and 92.3% for the training, validation, and test sets, respectively, and the specificity of 100% for each subset. It indicated that the combination of NIR spectroscopy and SPA-LDA algorithm can serve as a potential tool for distinguishing between normal and malignant colorectal tissues. PMID:25654106

  5. Visible and Near-Infrared Spectroscopy Analysis of a Polycyclic Aromatic Hydrocarbon in Soils

    PubMed Central

    Okparanma, Reuben N.; Mouazen, Abdul M.

    2013-01-01

    Visible and near-infrared (VisNIR) spectroscopy is becoming recognised by soil scientists as a rapid and cost-effective measurement method for hydrocarbons in petroleum-contaminated soils. This study investigated the potential application of VisNIR spectroscopy (350–2500 nm) for the prediction of phenanthrene, a polycyclic aromatic hydrocarbon (PAH), in soils. A total of 150 diesel-contaminated soil samples were used in the investigation. Partial least-squares (PLS) regression analysis with full cross-validation was used to develop models to predict the PAH compound. Results showed that the PAH compound was predicted well with residual prediction deviation of 2.0–2.32, root-mean-square error of prediction of 0.21–0.25 mg kg−1, and coefficient of determination (r2) of 0.75–0.83. The mechanism of prediction was attributed to covariation of the PAH with clay and soil organic carbon. Overall, the results demonstrated that the methodology may be used for predicting phenanthrene in soils utilizing the interrelationship between clay and soil organic carbon. PMID:24453798

  6. Classification of structurally related commercial contrast media by near infrared spectroscopy.

    PubMed

    Yip, Wai Lam; Soosainather, Tom Collin; Dyrstad, Knut; Sande, Sverre Arne

    2014-03-01

    Near infrared spectroscopy (NIRS) is a non-destructive measurement technique with broad application in pharmaceutical industry. Correct identification of pharmaceutical ingredients is an important task for quality control. Failure in this step can result in several adverse consequences, varied from economic loss to negative impact on patient safety. We have compared different methods in classification of a set of commercially available structurally related contrast media, Iodixanol (Visipaque(®)), Iohexol (Omnipaque(®)), Caldiamide Sodium and Gadodiamide (Omniscan(®)), by using NIR spectroscopy. The performance of classification models developed by soft independent modelling of class analogy (SIMCA), partial least squares discriminant analysis (PLS-DA) and Main and Interactions of Individual Principal Components Regression (MIPCR) were compared. Different variable selection methods were applied to optimize the classification models. Models developed by backward variable elimination partial least squares regression (BVE-PLS) and MIPCR were found to be most effective for classification of the set of contrast media. Below 1.5% of samples from the independent test set were not recognized by the BVE-PLS and MIPCR models, compared to up to 15% when models developed by other techniques were applied. PMID:24374816

  7. Intelligent sensing sensory quality of Chinese rice wine using near infrared spectroscopy and nonlinear tools.

    PubMed

    Ouyang, Qin; Chen, Quansheng; Zhao, Jiewen

    2016-02-01

    The approach presented herein reports the application of near infrared (NIR) spectroscopy, in contrast with human sensory panel, as a tool for estimating Chinese rice wine quality; concretely, to achieve the prediction of the overall sensory scores assigned by the trained sensory panel. Back propagation artificial neural network (BPANN) combined with adaptive boosting (AdaBoost) algorithm, namely BP-AdaBoost, as a novel nonlinear algorithm, was proposed in modeling. First, the optimal spectra intervals were selected by synergy interval partial least square (Si-PLS). Then, BP-AdaBoost model based on the optimal spectra intervals was established, called Si-BP-AdaBoost model. These models were optimized by cross validation, and the performance of each final model was evaluated according to correlation coefficient (Rp) and root mean square error of prediction (RMSEP) in prediction set. Si-BP-AdaBoost showed excellent performance in comparison with other models. The best Si-BP-AdaBoost model was achieved with Rp=0.9180 and RMSEP=2.23 in the prediction set. It was concluded that NIR spectroscopy combined with Si-BP-AdaBoost was an appropriate method for the prediction of the sensory quality in Chinese rice wine. PMID:26513226

  8. Comparison of torque measurements and near-infrared spectroscopy in characterization of a wet granulation process.

    PubMed

    Jørgensen, Anna Cecilia; Luukkonen, Pirjo; Rantanen, Jukka; Schaefer, Torben; Juppo, Anne Mari; Yliruusi, Jouko

    2004-09-01

    The purpose of this study was to compare impeller torque measurements and near-infrared (NIR) spectroscopy in the characterization of the water addition phase of a wet granulation process. Additionally, the effect of hydrate formation during granulation on the impeller torque was investigated. Anhydrous theophylline, alpha-lactose monohydrate, and microcrystalline cellulose (MCC) were used as materials for the study. The materials and mixtures of them were granulated using purified water in a small-scale high-shear mixer. The impeller torque was registered and NIR spectra of wet samples were recorded at-line. The torque and the NIR baseline-corrected water absorbances increased with increasing water content. A plateau in the NIR baseline-corrected water absorbances was observed for wet masses containing MCC. This was at the region of optimal water amount for granulation according to the torque results. In the case of anhydrous theophylline, the slope of baseline-corrected water absorbance values increased at the same water amount as the impeller torque started to increase. The hydrate formation of theophylline during granulation was observed as a slight decrease in the impeller torque. In addition, the hydrate formation during granulation affected the granulation liquid requirement. The liquid requirement was different for monohydrate formed during granulation compared to one formed in high relative humidity before the granulation. The results suggest that NIR spectroscopy may be applicable to process monitoring of wet granulation, also in cases where monitoring of impeller torque is difficult to apply. PMID:15295784

  9. On-site variety discrimination of tomato plant using visible-near infrared reflectance spectroscopy.

    PubMed

    Xu, Hui-rong; Yu, Peng; Fu, Xia-ping; Ying, Yi-Bin

    2009-02-01

    The use of visible-near infrared (NIR) spectroscopy was explored as a tool to discriminate two new tomato plant varieties in China (Zheza205 and Zheza207). In this study, 82 top-canopy leaves of Zheza205 and 86 top-canopy leaves of Zheza207 were measured in visible-NIR reflectance mode. Discriminant models were developed using principal component analysis (PCA), discriminant analysis (DA), and discriminant partial least squares (DPLS) regression methods. After outliers detection, the samples were randomly split into two sets, one used as a calibration set (n=82) and the remaining samples as a validation set (n=82). When predicting the variety of the samples in validation set, the classification correctness of the DPLS model after optimizing spectral pretreatment was up to 93%. The DPLS model with raw spectra after multiplicative scatter correction and Savitzky-Golay filter smoothing pretreatments had the best satisfactory calibration and prediction abilities (correlation coefficient of calibration (R(c))=0.920, root mean square errors of calibration=0.196, and root mean square errors of prediction=0.216). The results show that visible-NIR spectroscopy might be a suitable alternative tool to discriminate tomato plant varieties on-site. PMID:19235271

  10. Quality Evaluation of Shelled and Unshelled Macadamia Nuts by Means of Near-Infrared Spectroscopy (NIR).

    PubMed

    Canneddu, Giovanna; Júnior, Luis Carlos Cunha; de Almeida Teixeira, Gustavo Henrique

    2016-07-01

    The quality of shelled and unshelled macadamia nuts was assessed by means of Fourier transformed near-infrared (FT-NIR) spectroscopy. Shelled macadamia nuts were sorted as sound nuts; nuts infected by Ecdytolopha aurantiana and Leucopteara coffeella; and cracked nuts caused by germination. Unshelled nuts were sorted as intact nuts (<10% half nuts, 2014); half nuts (March, 2013; November, 2013); and crushed nuts (2014). Peroxide value (PV) and acidity index (AI) were determined according to AOAC. PCA-LDA shelled macadamia nuts classification resulted in 93.2% accurate classification. PLS PV prediction model resulted in a square error of prediction (SEP) of 3.45 meq/kg, and a prediction coefficient determination value (Rp (2) ) of 0.72. The AI PLS prediction model was better (SEP = 0.14%, Rp (2) = 0.80). Although adequate classification was possible (93.2%), shelled nuts must not contain live insects, therefore the classification accuracy was not satisfactory. FT-NIR spectroscopy can be successfully used to predict PV and AI in unshelled macadamia nuts, though. PMID:27228399

  11. Near-infrared (NIR) Raman spectroscopy of Precambrian carbonate stromatolites with post-depositional organic inclusions.

    PubMed

    Tanaka, Zuki; Perry, Meredith; Cooper, George; Tang, Suning; McKay, Christopher P; Chen, Bin

    2012-08-01

    Raman spectroscopy has promising potential for future Mars missions as a non-contact detection technique for characterizing organic material and mineralogy. Such a capability will be useful for selecting samples for detailed analysis on a rover and for selecting samples for return to Earth. Stromatolites are important evidence for the earliest life on Earth and are promising targets for Mars investigations. Although constructed by microorganisms, stromatolites are organo-sedimentary structures that can be large enough to be discovered and investigated by a Mars rover. In this paper, we report the Raman spectroscopic investigations of the carbonate mineralogy and organic layering in a Precambrian (~1.5 Gyr old) stromatolite from the Crystal Spring Formation of Southern California. Ultraviolet (UV: 266 nm), visible (514 nm, 633 nm), and near-infrared (NIR: 785 nm, 1064 nm) Raman spectra are presented. We conclude that 1064 nm excitation is the optimal excitation wavelength for avoiding intrinsic fluorescence and detecting organic carbon within the carbonate matrix. Our results confirm that NIR Raman spectroscopy has important applications for future Mars missions. PMID:22800768

  12. Determination of effective wavelengths for discrimination of fruit vinegars using near infrared spectroscopy and multivariate analysis.

    PubMed

    Liu, Fei; He, Yong; Wang, Li

    2008-05-12

    Near infrared (NIR) spectroscopy based on effective wavelengths (EWs) and chemometrics was proposed to discriminate the varieties of fruit vinegars including aloe, apple, lemon and peach vinegars. One hundred eighty samples (45 for each variety) were selected randomly for the calibration set, and 60 samples (15 for each variety) for the validation set, whereas 24 samples (6 for each variety) for the independent set. Partial least squares discriminant analysis (PLS-DA) and least squares-support vector machine (LS-SVM) were implemented for calibration models. Different input data matrices of LS-SVM were determined by latent variables (LVs) selected by explained variance, and EWs selected by x-loading weights, regression coefficients, modeling power and independent component analysis (ICA). Then the LS-SVM models were developed with a grid search technique and RBF kernel function. All LS-SVM models outperformed PLS-DA model, and the optimal LS-SVM model was achieved with EWs (4021, 4058, 4264, 4400, 4853, 5070 and 5273 cm(-1)) selected by regression coefficients. The determination coefficient (R(2)), RMSEP and total recognition ratio with cutoff value +/-0.1 in validation set were 1.000, 0.025 and 100%, respectively. The overall results indicted that the regression coefficients was an effective way for the selection of effective wavelengths. NIR spectroscopy combined with LS-SVM models had the capability to discriminate the varieties of fruit vinegars with high accuracy. PMID:18440358

  13. Intelligent sensing sensory quality of Chinese rice wine using near infrared spectroscopy and nonlinear tools

    NASA Astrophysics Data System (ADS)

    Ouyang, Qin; Chen, Quansheng; Zhao, Jiewen

    2016-02-01

    The approach presented herein reports the application of near infrared (NIR) spectroscopy, in contrast with human sensory panel, as a tool for estimating Chinese rice wine quality; concretely, to achieve the prediction of the overall sensory scores assigned by the trained sensory panel. Back propagation artificial neural network (BPANN) combined with adaptive boosting (AdaBoost) algorithm, namely BP-AdaBoost, as a novel nonlinear algorithm, was proposed in modeling. First, the optimal spectra intervals were selected by synergy interval partial least square (Si-PLS). Then, BP-AdaBoost model based on the optimal spectra intervals was established, called Si-BP-AdaBoost model. These models were optimized by cross validation, and the performance of each final model was evaluated according to correlation coefficient (Rp) and root mean square error of prediction (RMSEP) in prediction set. Si-BP-AdaBoost showed excellent performance in comparison with other models. The best Si-BP-AdaBoost model was achieved with Rp = 0.9180 and RMSEP = 2.23 in the prediction set. It was concluded that NIR spectroscopy combined with Si-BP-AdaBoost was an appropriate method for the prediction of the sensory quality in Chinese rice wine.

  14. [Main Components of Xinjiang Lavender Essential Oil Determined by Partial Least Squares and Near Infrared Spectroscopy].

    PubMed

    Liao, Xiang; Wang, Qing; Fu, Ji-hong; Tang, Jun

    2015-09-01

    This work was undertaken to establish a quantitative analysis model which can rapid determinate the content of linalool, linalyl acetate of Xinjiang lavender essential oil. Totally 165 lavender essential oil samples were measured by using near infrared absorption spectrum (NIR), after analyzing the near infrared spectral absorption peaks of all samples, lavender essential oil have abundant chemical information and the interference of random noise may be relatively low on the spectral intervals of 7100~4500 cm(-1). Thus, the PLS models was constructed by using this interval for further analysis. 8 abnormal samples were eliminated. Through the clustering method, 157 lavender essential oil samples were divided into 105 calibration set samples and 52 validation set samples. Gas chromatography mass spectrometry (GC-MS) was used as a tool to determine the content of linalool and linalyl acetate in lavender essential oil. Then the matrix was established with the GC-MS raw data of two compounds in combination with the original NIR data. In order to optimize the model, different pretreatment methods were used to preprocess the raw NIR spectral to contrast the spectral filtering effect, after analysizing the quantitative model results of linalool and linalyl acetate, the root mean square error prediction (RMSEP) of orthogonal signal transformation (OSC) was 0.226, 0.558, spectrally, it was the optimum pretreatment method. In addition, forward interval partial least squares (FiPLS) method was used to exclude the wavelength points which has nothing to do with determination composition or present nonlinear correlation, finally 8 spectral intervals totally 160 wavelength points were obtained as the dataset. Combining the data sets which have optimized by OSC-FiPLS with partial least squares (PLS) to establish a rapid quantitative analysis model for determining the content of linalool and linalyl acetate in Xinjiang lavender essential oil, numbers of hidden variables of two

  15. In-line multipoint near-infrared spectroscopy for moisture content quantification during freeze-drying.

    PubMed

    Kauppinen, Ari; Toiviainen, Maunu; Korhonen, Ossi; Aaltonen, Jaakko; Järvinen, Kristiina; Paaso, Janne; Juuti, Mikko; Ketolainen, Jarkko

    2013-02-19

    During the past decade, near-infrared (NIR) spectroscopy has been applied for in-line moisture content quantification during a freeze-drying process. However, NIR has been used as a single-vial technique and thus is not representative of the entire batch. This has been considered as one of the main barriers for NIR spectroscopy becoming widely used in process analytical technology (PAT) for freeze-drying. Clearly it would be essential to monitor samples that reliably represent the whole batch. The present study evaluated multipoint NIR spectroscopy for in-line moisture content quantification during a freeze-drying process. Aqueous sucrose solutions were used as model formulations. NIR data was calibrated to predict the moisture content using partial least-squares (PLS) regression with Karl Fischer titration being used as a reference method. PLS calibrations resulted in root-mean-square error of prediction (RMSEP) values lower than 0.13%. Three noncontact, diffuse reflectance NIR probe heads were positioned on the freeze-dryer shelf to measure the moisture content in a noninvasive manner, through the side of the glass vials. The results showed that the detection of unequal sublimation rates within a freeze-dryer shelf was possible with the multipoint NIR system in use. Furthermore, in-line moisture content quantification was reliable especially toward the end of the process. These findings indicate that the use of multipoint NIR spectroscopy can achieve representative quantification of moisture content and hence a drying end point determination to a desired residual moisture level. PMID:23351045

  16. Advances in R&D in near-infrared spectroscopy in Japan

    NASA Astrophysics Data System (ADS)

    Kawano, Sumio; Iwamoto, Mutsuo

    1991-02-01

    More than 20 years ago when Mr. K. H. Norris firstly introduced the near infrared spectroscopy (NIRS) as a powerful technology in the field of composition analysis of cereals those who were interested in the area of classical spectroscopy would not like to recognize its potential. This tendency still remains at present however it leaves no room for doubt that from viewpoints of applied spectroscopy the NIRS has consolidated its position. From a viewpoint of NIRS application in the field of nondestructive or non invasive measuring techniques history of this technology is only the last decade in Japan. However since the technology was firstly introduced to composition analysis of agricultural commodities in the same manner as in other countries R and D have been growing more actively in diversified fields such as agriculture and industry as well as medical science. In addition the NIRS technology are becoming of general interest by combining other techniques to create various hyphenated instrumentations such as FTNIR MCFTNIR NIRCT and NIR-NMR. In this paper new trends of R D on NIR spectroscopy which are being conducted in Japan will be reviewed. 2. S1JMMARY OF PRESENT R D ON NIRS IN JAPAN NIRS applications reported in the last 3 years are summarized in Table 1. Table 1 Applications of NIRS in Japan Application for Agriculture Taste evaluation of rice and coffee Determination of chemical compositions rice for breeding Determination of chemical compositions in tea Determination of sugar contents in intact peaches Japanese pears Satsuma oranges and apples Determination of sugars and acids in intact tomatoes Determination of forage composition Application for Industry Analysis of state of water in foods Application of analyzing Maillard Reaction''s Process Pattern recognition of NIR spectra as related to process control of roasting coffee beans Quality control of tea processing Determination of moisture content of Surimi products 2 / SPIE Vol. 1379 Optics in Agriculture

  17. Classification of the waxy condition of durum wheat by near infrared reflectance spectroscopy using wavelets and a genetic algorithm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Near infrared (NIR) reflectance spectroscopy has been applied to the problem of differentiating four genotypes of durum wheat: ‘waxy’, wx-A1 null, wx-B1 null and wild type. The test data consisted of 95 NIR reflectance spectra of wheat samples obtained from a USDA-ARS wheat breeding program. A two...

  18. Use of visible-near infrared reflectance spectroscopy to assess soil quality related to long-term tillage effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Visible-near infrared diffuse reflectance spectroscopy (VNIRDRS) is emerging as an effective method for rapid evaluation of soil properties and may be promising for the simultaneous determination of soil quality indicators. This study employed VNIRDRS to analyze treatment effects associated with lo...

  19. Determining weight and moisture properties of sound and fusarium-damaged single wheat kernels by near infrared spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Single kernel moisture content (MC) is important in the measurement of other quality traits in single kernels since many traits are expressed on a dry weight basis, and MC affects viability, storage quality, and price. Also, if near-infrared (NIR) spectroscopy is used to measure grain traits, the in...

  20. Rapid and non-destructive detection and identification two strains of Wolbachia in Aedes aegypti by near-infrared spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigated the potential of using near-infrared spectroscopy (NIRS) to detect the presence of Wolbachia pipientis (wMel) in male and female laboratory-reared Aedes aegypti mosquitoes. The release of Wolbachia transinfected mosquitoes is likely to form a key component of disease control strategi...

  1. A Quantitative Near-Infrared Spectroscopy Study: A Decrease in Cerebral Hemoglobin Oxygenation in Alzheimer's Disease and Mild Cognitive Impairment

    ERIC Educational Resources Information Center

    Arai, Heii; Takano, Maki; Miyakawa, Koichi; Ota, Tsuneyoshi; Takahashi, Tadashi; Asaka, Hirokazu; Kawaguchi, Tsuneaki

    2006-01-01

    A newly developed quantitative near-infrared spectroscopy (NIRS) system was used to measure changes in cortical hemoglobin oxygenation during the Verbal Fluency Task in 32 healthy controls, 15 subjects with mild cognitive impairment (MCI), and 15 patients with Alzheimer's disease (AD). The amplitude of changes in the waveform, which was…

  2. Near-infrared spectroscopy as a complementary age grading and species identification tool for African malaria vectors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Near-infrared spectroscopy (NIRS) was recently applied to age-grade and differentiate laboratory reared Anopheles gambiae sensu strico and Anopheles arabiensis sibling species of Anopheles gambiae sensu lato. In this study, we report further on the accuracy of this tool in simultaneously estimating ...

  3. Evaluating RNAlater® as a preservative for using near-infrared spectroscopy to predict Anopheles gambiae age and species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mosquito age and species identification is a crucial determinant of the efficacy of vector control programs. Near-infrared spectroscopy (NIRS) has previously been applied successfully to rapidly, non-destructively, and simultaneously determine the age and species of freshly anesthetized African mala...

  4. Use of Near-Infrared Spectroscopy to Age-Grade and Identify Siblings of Anopheles Gambiae Complex

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We used near-infrared spectroscopy (NIRS) to rapidly and non-destructively determine species and age of Anopheles gambiae ss (G3, Mali-NIH, Kisumu, ZANU, and Ifakara strains) and An. arabiensis (Dongola, KGB, and Ifakara strains). We developed NIR calibrations using mosquitoes reared and scanned at ...

  5. Estimating and validating the interbeat intervals of the heart using near-infrared spectroscopy on the human forehead

    NASA Astrophysics Data System (ADS)

    Trajkovic, Ivo; Scholkmann, Felix; Wolf, Martin

    2011-08-01

    In studies with near-infrared spectroscopy, the recorded signals contain information on the temporal interbeat intervals of the heart. If this cardiac information is needed exclusively and could directly be extracted, an additional electrocardiography device would be unnecessary. The aim was to estimate these intervals from signals measured with near-infrared spectroscopy with two novel approaches. In one approach, we model the heartbeat oscillations in these signals with a Fourier series where the coefficients and the fundamental frequency can continuously change over time. The time-dependent model parameters are estimated and used to calculate the interbeat intervals. The second approach uses empirical mode decomposition. The signal measured with near-infrared spectroscopy is empirically decomposed into a set of oscillatory components. The sum of a specific subset of them is an estimate of the pure heartbeat signal in which the diastolic peaks and consequential interbeat intervals are detected. We show in simultaneous electrocardiography and near-infrared spectroscopy measurements on 11 subjects (8 men and 3 woman with mean age 32.8 +/- 8.1 yr), that the interbeat intervals (and the consequential pulse rate variability measures), estimated using the proposed approaches, are in high agreement with their correspondents from electrocardiography.

  6. Task Dependent Prefrontal Dysfunction in Persons with Asperger's Disorder Investigated with Multi-Channel Near-Infrared Spectroscopy

    ERIC Educational Resources Information Center

    Iwanami, Akira; Okajima, Yuka; Ota, Haruhisa; Tani, Masayuki; Yamada, Takashi; Hashimoro, Ryuichiro; Kanai, Chieko; Watanabe, Hiromi; Yamasue, Hidenori; Kawakubo, Yuki; Kato, Nobumasa

    2011-01-01

    Dysfunction of the prefrontal cortex has been previously reported in individuals with Asperger's disorder. In the present study, we used multi-channel near-infrared spectroscopy (NIRS) to detect changes in the oxygenated hemoglobin concentration ([oxy-Hb]) during two verbal fluency tasks. The subjects were 20 individuals with Asperger's disorder…

  7. Co-Speech Gesture Production in an Animation-Narration Task by Bilinguals: A Near-Infrared Spectroscopy Study

    ERIC Educational Resources Information Center

    Oi, Misato; Saito, Hirofumi; Li, Zongfeng; Zhao, Wenjun

    2013-01-01

    To examine the neural mechanism of co-speech gesture production, we measured brain activity of bilinguals during an animation-narration task using near-infrared spectroscopy. The task of the participants was to watch two stories via an animated cartoon, and then narrate the contents in their first language (Ll) and second language (L2),…

  8. Shelf life study of egg albumin in pasteurized and non-pasteurized eggs using visible-near infrared spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A twelve week shelf life study was conducted on the egg albumen from both pasteurized and non-pasteurized shell eggs using visible-near infrared spectroscopy. The goal of the study was to correlate the chemical changes detected in the spectra to the measurement of Haugh units (measure of interior eg...

  9. Reduced Prefrontal Hemodynamic Response in Pediatric Obsessive-Compulsive Disorder as Measured by Near-Infrared Spectroscopy

    ERIC Educational Resources Information Center

    Ota, Toyosaku; Iida, Junzo; Sawada, Masayuki; Suehiro, Yuko; Yamamuro, Kazuhiko; Matsuura, Hiroki; Tanaka, Shohei; Kishimoto, Naoko; Negoro, Hideki; Kishimoto, Toshifumi

    2013-01-01

    Recent developments in near-infrared spectroscopy (NIRS) have enabled non-invasive clarification of brain functions in psychiatric disorders. Functional neuroimaging studies of patients with obsessive-compulsive disorder (OCD) have suggested that the frontal cortex and subcortical structures may play a role in the pathophysiology of the disorder.…

  10. Quantitative analysis of cefalexin based on artificial neural networks combined with modified genetic algorithm using short near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Huan, Yanfu; Feng, Guodong; Wang, Bin; Ren, Yulin; Fei, Qiang

    2013-05-01

    In this paper, a novel chemometric method was developed for rapid, accurate, and quantitative analysis of cefalexin in samples. The experiments were carried out by using the short near-infrared spectroscopy coupled with artificial neural networks. In order to enhancing the predictive ability of artificial neural networks model, a modified genetic algorithm was used to select fixed number of wavelength.

  11. Hemodynamic and Electrophysiological Connectivity in the Language System: Simultaneous Near-Infrared Spectroscopy and Electrocorticography Recordings during Cortical Stimulation

    ERIC Educational Resources Information Center

    Sato, Yosuke; Oishi, Makoto; Fukuda, Masafumi; Fujii, Yukihiko

    2012-01-01

    We applied near-infrared spectroscopy (NIRS) and electrocorticography (ECoG) recordings during cortical stimulation to a temporal lobe epilepsy patient who underwent subdural electrode implantation. Using NIRS, changes in blood concentrations of oxyhemoglobin (HbO[subscript 2]) and deoxyhemoglobin (HbR) during cortical stimulation of the left…

  12. In-stream measurement of canola (Brassica napus L.) seed oil concentration using in-line near infrared reflectance spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Natural variation in the seed oil concentration of oilseed crops can impair a crushing plant’s ability to efficiently recover the oil from seed. Consequently, there is interest in using in-line near infrared (NIR) spectroscopy to measure the oil concentration of the seed to be processed and use thi...

  13. Prediction of dissolution profiles by non-destructive near infrared spectroscopy in tablets subjected to different levels of strain.

    PubMed

    Hernandez, Eduardo; Pawar, Pallavi; Keyvan, Golshid; Wang, Yifan; Velez, Natasha; Callegari, Gerardo; Cuitino, Alberto; Michniak-Kohn, Bozena; Muzzio, Fernando J; Romañach, Rodolfo J

    2016-01-01

    This study describes how the strain on formulation components affects dissolution and how near infrared spectroscopy can be used to predict dissolution. Strain (exposure to shear stress) applied during powder mixing affects the interaction between formulation components. Particles experience shear strain when they move relative to each other in a process affecting the properties of the final product. This stress affects the dissolution of oral solid dosages forms. However, dissolution testing destroys the entire tablet, making it impossible to further evaluate tablet properties when an out of specification result is obtained. Thus, a nondestructive technique such as near infrared spectroscopy is desirable to predict dissolution. The aim of this study was to predict dissolution on tablets with different levels of strain (shear) using near infrared spectroscopy in combination with multivariate data analysis. Shear was induced using a modified Couette cell on the powder mixture and tablets from these mixtures were produced using a tablet press emulator. Tablets produced with different strain levels were measured using near infrared spectroscopy. Spectra were obtained in diffuse reflectance mode and pretreated with baseline correction to maintain the physical and chemical information of the tablets. Dissolution profiles were obtained using USP Apparatus 2 as a reference method. Principal component analysis was used to study the sources of variation in the spectra obtained. Partial least squares 2 was used to predict dissolution on tablets with different levels of strain. PMID:26604167

  14. PREDICTION OF COLOR, TENDERNESS, AND SENSORY CHARACTERISTICS OF BEEF STEAKS BY VISIBLE AND NEAR INFRARED REFLECTANCE SPECTROSCOPY. A FEASIBILITY STUDY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Color, texture and sensory attributes of 24 beef carcasses at 2, 4, 8, 14, and 21 days post mortem were predicted by visible/near infrared (visible/NIR) reflectance spectroscopy in 400-1080 nm region. Predicting the Hunter a*, b*, and E* values yielded the coefficient of determination (R**2) in cal...

  15. Asymmetrical Brain Activity Induced by Voluntary Spatial Attention Depends on the Visual Hemifield: A Functional Near-Infrared Spectroscopy Study

    ERIC Educational Resources Information Center

    Harasawa, Masamitsu; Shioiri, Satoshi

    2011-01-01

    The effect of the visual hemifield to which spatial attention was oriented on the activities of the posterior parietal and occipital visual cortices was examined using functional near-infrared spectroscopy in order to investigate the neural substrates of voluntary visuospatial attention. Our brain imaging data support the theory put forth in a…

  16. Feasibility of near infrared spectroscopy for analyzing corn kernel damage and viability of soybean and corn kernels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The current US corn grading system accounts for the portion of damaged kernels, which is measured by time-consuming and inaccurate visual inspection. Near infrared spectroscopy (NIRS), a non-destructive and fast analytical method, was tested as a tool for discriminating corn kernels with heat and f...

  17. Enhanced single seed trait predictions in soybean (Glycine max) and robust calibration model transfer with near infrared reflectance spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Single seed near infrared reflectance (NIR) spectroscopy predicts soybean (Glycine max) seed quality traits of moisture, oil, and protein. We tested the accuracy of transferring calibrations between different single seed NIR analyzers of the same design by collecting NIR spectra and analytical trait...

  18. Corrected near infrared spectroscopy, C-NIRS: An optical system for extracting hemodynamic signatures unique to the brain

    NASA Astrophysics Data System (ADS)

    Saager, Rolf B.

    We propose a method, dubbed Corrected Near Infrared Spectroscopy (C-NIRS), to isolate absorption trends confined to the lower layer of a two-layer turbid medium, as is desired in near-infrared spectroscopy (NIRS) of cerebral hemodynamics. The theory behind the operation of this method has been developed and discussed. Several two-layer Monte-Carlo simulations of NIRS time series were generated using a physiologically relevant range of optical properties. Initial results show that by measuring absorption trends at two source-detector separations and performing a least-squares fit of one to the other, processed signals strongly resemble the simulated absorption properties unique to the bottom-layer. Through this approach, it has been demonstrated that fitting coefficients can be estimated without any a priori knowledge of the optical properties present in the model. An analytical approximation for the least squares coefficient provides physical insight into the nature of errors and suggests ways to reduce them. Next, a multi-detector, continuous wave, near infrared spectroscopy system has been developed to examine whether the hemodynamics of the scalp and brain in adults contain significant layer-like hemodynamic trends. NIRS measurements were made using contrasting geometries, one with four detectors equidistant from a source 33 mm away, and one with detectors collinear with the source (5-33 mm away). When NIRS time series were acquired over the prefrontal cortex from resting adults using both geometries, variations among the time series were consistent with a substantially homogeneous two-layer model ( p < 0.001) and inconsistent with one dominated by heterogeneities. Additionally, when time series measured 5 mm from the source were subtracted from corresponding 33 mm signals via a least-squares algorithm, 60% of the hemoglobin changes were on average removed. These results suggest that hemodynamic trends present in the scalp can contribute significantly to NIRS

  19. Visible and near-infrared reflectivity of solid and liquid methane: application to spectroscopy of Titan's hydrocarbon lakes

    NASA Astrophysics Data System (ADS)

    Adams, K.; Jacobsen, S. D.; Liu, Z.; Somayazulu, M.; Thomas, S.; Jurdy, D. M.

    2011-12-01

    Reflectance spectroscopy provides one of the few direct observations of outer solar system bodies for interpreting their surface compositions. At Titan, the Visual and Infrared Mapping Spectrometer (VIMS) on board the Cassini spacecraft revealed dark patches on the surface through the narrow 2 and 5 μm windows of Titan's atmosphere, which have been interpreted as hydrocarbon lakes forming seasonally through a methane cycle. Whereas the composition of planetary materials in the solar system has been inferred from characteristic absorption bands, the need to identify phase states (liquid versus solid) on dynamic planetary surfaces requires laboratory reflectance ratio measurements at relevant temperatures. Using visible and near-infrared radiation from the National Synchrotron Light Source (NSLS), we will present confocal reflectance ratio measurements of solid (single crystal) and liquid CH4 at temperatures from 50-100 K. Although the position and shape of the six characteristic methane absorption bands at around 1.7 and 2.3 μm are insensitive to temperature or phase state from 50-100 K, the broad-spectrum reflectance between 0.5-2 μm decreases upon melting by about 25% at 87-94 K. Transition from solid CH4-I to liquid states at ~90 K displays a reflectance ratio (sold/liquid) of about 1.3 at 2 μm. Darkening of CH4 upon melting is similar at visible wavelengths, and consistent with VIMS observations of hydrocarbon lakes in the far northern and southern latitudes of Titan.

  20. Wide-area remote-sensing system of pollution and gas dispersal by near-infrared absorption based on low-loss optical fiber network

    NASA Technical Reports Server (NTRS)

    Inaba, H.

    1986-01-01

    An all optical remote sensing system utilizing long distance, ultralow loss optical fiber networks is studied and discussed for near infrared absorption measurements of combustible and/or explosive gases such as CH4 and C3H8 in our environment, including experimental results achieved in a diameter more than 20 km. The use of a near infrared wavelength range is emphasized.

  1. Water sorption on martian regolith analogs: Thermodynamics and near-infrared reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    Pommerol, Antoine; Schmitt, Bernard; Beck, Pierre; Brissaud, Olivier

    2009-11-01

    The near-infrared reflectance spectra of the martian surface present strong absorption features attributed to hydration water present in the regolith. In order to characterize the relationships between this water and atmospheric vapor and decipher the physical state of water molecules in martian regolith analogs, we designed and built an experimental setup to measure near-IR reflectance spectra under martian atmospheric conditions. Six samples were studied that cover part of the diversity of Mars surface mineralogy: a hydrated ferric oxide (ferrihydrite), two igneous samples (volcanic tuff, and dunite sand), and three potential water rich soil materials (Mg-sulfate, smectite powder and a palagonitic soil, the JSC Mars-1 regolith stimulant). Sorption and desorption isotherms were measured at 243 K for water vapor pressure varying from 10 -5 to ˜0.3 mbar (relative humidity: 10 -4 to 75%). These measurements reveal a large diversity of behavior among the sample suite in terms of absolute amount of water adsorbed, shape of the isotherm and hysteresis between the adsorption and desorption branches. Simultaneous in situ spectroscopic observations permit a detailed analysis of the spectral signature of adsorbed water and also point to clear differences between the samples. Ferric (oxy)hydroxides like ferrihydrite or other phases present in palagonitic soils are very strong water adsorbent and may play an important role in the current martian water cycle by allowing large exchange of water between dust-covered regions and atmosphere at diurnal and seasonal scales.

  2. Near infrared iron absorption bands: Applications to geologic mapping and mineral exploration

    NASA Technical Reports Server (NTRS)

    Rowan, L. C.

    1972-01-01

    A spectroscopic analysis of the difference in reflectance of iron-rich and iron-poor minerals was made. Attempts were made to use these minima contrast in geological mapping and metallic mineral exploration of large areas from near infrared and visible satellite images. Data cover pertinent laboratory spectroscopic investigations, applications of spectral differences to the discrimination of two important metamorphic rock types, and mineral exploration by aircraft in Beartooth Mountains, Montana.

  3. Automatic and Rapid Discrimination of Cotton Genotypes by Near Infrared Spectroscopy and Chemometrics

    PubMed Central

    Cui, Hai-Feng; Ye, Zi-Hong; Xu, Lu; Fu, Xian-Shu; Fan, Cui-Wen; Yu, Xiao-Ping

    2012-01-01

    This paper reports the application of near infrared (NIR) spectroscopy and pattern recognition methods to rapid and automatic discrimination of the genotypes (parent, transgenic, and parent-transgenic hybrid) of cotton plants. Diffuse reflectance NIR spectra of representative cotton seeds (n = 120) and leaves (n = 123) were measured in the range of 4000–12000 cm−1. A practical problem when developing classification models is the degradation and even breakdown of models caused by outliers. Considering the high-dimensional nature and uncertainty of potential spectral outliers, robust principal component analysis (rPCA) was applied to each separate sample group to detect and exclude outliers. The influence of different data preprocessing methods on model prediction performance was also investigated. The results demonstrate that rPCA can effectively detect outliers and maintain the efficiency of discriminant analysis. Moreover, the classification accuracy can be significantly improved by second-order derivative and standard normal variate (SNV). The best partial least squares discriminant analysis (PLSDA) models obtained total classification accuracy of 100% and 97.6% for seeds and leaves, respectively. PMID:22666635

  4. Unleashing the future potential of functional near-infrared spectroscopy in brain sciences.

    PubMed

    Cutini, Simone; Brigadoi, Sabrina

    2014-07-30

    The wondrous innovations bound to the introduction of functional near-infrared spectroscopy in cognitive neuroscience are characterized by a multifaceted nature, ranging from technological improvements to sophisticated signal processing methods; the outstanding progress enabled scientists to investigate a variety of hard-to-test clinical populations and to successfully employ optical imaging in fields that were almost unimaginable twenty years ago. Here we illustrate how the emerging use of fNIRS methodologies might represent a drawing power in a variety of challenging experimental and medical contexts; we expect in the near future a wide increase of the use of wireless fNIRS, especially in children and in particular clinical populations, as well as a striking progress of fNIRS-BCI and hybrid BCI systems for neurofeedback and neurorehabilitation. These emerging trends might dramatically foster the future potential of fNIRS in brain sciences, provided that they are properly supported by a significant progress in signal processing and cognitive neuroscience. PMID:24880046

  5. Evaluation of green coffee beans quality using near infrared spectroscopy: a quantitative approach.

    PubMed

    Santos, João Rodrigo; Sarraguça, Mafalda C; Rangel, António O S S; Lopes, João A

    2012-12-01

    Characterisation of coffee quality based on bean quality assessment is associated with the relative amount of defective beans among non-defective beans. It is therefore important to develop a methodology capable of identifying the presence of defective beans that enables a fast assessment of coffee grade and that can become an analytical tool to standardise coffee quality. In this work, a methodology for quality assessment of green coffee based on near infrared spectroscopy (NIRS) is proposed. NIRS is a green chemistry, low cost, fast response technique without the need of sample processing. The applicability of NIRS was evaluated for Arabica and Robusta varieties from different geographical locations. Partial least squares regression was used to relate the NIR spectrum to the mass fraction of defective and non-defective beans. Relative errors around 5% show that NIRS can be a valuable analytical tool to be used by coffee roasters, enabling a simple and quantitative evaluation of green coffee quality in a fast way. PMID:22953929

  6. Rapid estimation of nutritional elements on citrus leaves by near infrared reflectance spectroscopy

    PubMed Central

    Galvez-Sola, Luis; García-Sánchez, Francisco; Pérez-Pérez, Juan G.; Gimeno, Vicente; Navarro, Josefa M.; Moral, Raul; Martínez-Nicolás, Juan J.; Nieves, Manuel

    2015-01-01

    Sufficient nutrient application is one of the most important factors in producing quality citrus fruits. One of the main guides in planning citrus fertilizer programs is by directly monitoring the plant nutrient content. However, this requires analysis of a large number of leaf samples using expensive and time-consuming chemical techniques. Over the last 5 years, it has been demonstrated that it is possible to quantitatively estimate certain nutritional elements in citrus leaves by using the spectral reflectance values, obtained by using near infrared reflectance spectroscopy (NIRS). This technique is rapid, non-destructive, cost-effective and environmentally friendly. Therefore, the estimation of macro and micronutrients in citrus leaves by this method would be beneficial in identifying the mineral status of the trees. However, to be used effectively NIRS must be evaluated against the standard techniques across different cultivars. In this study, NIRS spectral analysis, and subsequent nutrient estimations for N, K, Ca, Mg, B, Fe, Cu, Mn, and Zn concentration, were performed using 217 leaf samples from different citrus trees species. Partial least square regression and different pre-processing signal treatments were used to generate the best estimation against the current best practice techniques. It was verified a high proficiency in the estimation of N (Rv = 0.99) and Ca (Rv = 0.98) as well as achieving acceptable estimation for K, Mg, Fe, and Zn. However, no successful calibrations were obtained for the estimation of B, Cu, and Mn. PMID:26257767

  7. Development of motion resistant instrumentation for ambulatory near-infrared spectroscopy.

    PubMed

    Zhang, Quan; Yan, Xiangguo; Strangman, Gary E

    2011-08-01

    Ambulatory near-infrared spectroscopy (aNIRS) enables recording of systemic or tissue-specific hemodynamics and oxygenation during a person's normal activities. It has particular potential for the diagnosis and management of health problems with unpredictable and transient hemodynamic symptoms, or medical conditions requiring continuous, long-duration monitoring. aNIRS is also needed in conditions where regular monitoring or imaging cannot be applied, including remote environments such as during spaceflight or at high altitude. One key to the successful application of aNIRS is reducing the impact of motion artifacts in aNIRS recordings. In this paper, we describe the development of a novel prototype aNIRS monitor, called NINscan, and our efforts to reduce motion artifacts in aNIRS monitoring. Powered by 2 AA size batteries and weighting 350 g, NINscan records NIRS, ECG, respiration, and acceleration for up to 14 h at a 250 Hz sampling rate. The system's performance and resistance to motion is demonstrated by long term quantitative phantom tests, Valsalva maneuver tests, and multiparameter monitoring during parabolic flight and high altitude hiking. To the best of our knowledge, this is the first report of multiparameter aNIRS monitoring and its application in parabolic flight. PMID:21895335

  8. [EEMD-ICA Applied in Signal Extraction in Functional Near-Infrared Spectroscopy].

    PubMed

    Zha, Yu-tong; Liu, Guang-da; Zhou, Run-dong; Zhang, Xiao-feng; Niu, Jun-qi; Yu, Yong; Wang, Wei

    2015-10-01

    Currently, functional near-infrared spectroscopy (fNIRS) is widely used in the field of Neuroimaging. To solve the signal-noise frequency spectrum aliasing in non-linear and non-stationary fNIRS characteristic signal extraction, a new joint multi-resolution algorithm, EEMD-ICA, is proposed based on combining Independent Component Analysis with Ensemble Empirical Mode Decomposing. After functional brain imaging instrument detected the multi-channel and multi-wavelength NIR optical density signals, EEMD was performed to decompose measurement signals into multiple intrinsic mode function according to the signal frequency component. Then ICA was applied to extract the interest data from IMFs into ICs. Finally, reconstructed signals were obtained by accumulating the ICs set. EEMD-ICA was applied in de-noising Valsalva test signals which were considered as original signals and compared with Empirical Mode Decomposing and Ensemble Empirical Mode Decomposing to illustrate validity of this algorithm. It is proved that useful information loss during de-noising and invalidity of noise elimination are completely solved by EEMD-ICA. This algorithm is more optimized than other two de-noising methods in error parameters and signal-noise-ratio analysis. PMID:26904811

  9. Study on memories of temporal lobes and the principles of lateralization using near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Kamakura, Katsutoshi

    2007-01-01

    In this study we measured the variation of brain blood quantity (Oxy-Hb, Deoxy-Hb and Total-Hb) in the temporal lobes using near infrared spectroscopy (NIRS) when the tasks of the memories were presented to the subjects. The memories are classified into the short-term memory (STM) and the long-term memory (LTM) including the episodic and semantic memories. The subjects joined in this study are 11 persons who are university students including graduate students. We used the language task of letter-number sequencing, also reverse sequencing to measure STM and the task of the episodic memory to measure LTM. As a result of analysis, concerning the episodic memory, the variation of Oxy-Hb in the left temporal lobe was larger than that of Oxy-Hb in the right temporal lobe. The result might suggest that the episodic memory has a relationship with cerebral dominance concerning language area in the left temporal lobe. It seems that the episodic memory meditated with the function of language used in this study is much stored in the left temporal lobe than in the right temporal lobe. This result coincides with the principles of lateralization. The variation of Oxy-Hb in the language task of letter-number sequencing was smaller than that of Oxy-Hb in the language task of the episodic memory.

  10. Valence processing of first impressions in the dorsomedial prefrontal cortex: a near-infrared spectroscopy study.

    PubMed

    Yu, Chi-Lin; Wang, Min-Ying; Hu, Jon-Fan

    2016-05-25

    Previous studies have suggested that the dorsomedial prefrontal cortex (dmPFC) plays a central role in processing first impressions; however, little is known about how dmPFC processes different valences of first impressions. Moreover, it is still unclear as to whether the dmPFC shows lateralization or only induces different levels of activation when processing positive and negative impressions. To address these questions in the present study, the brain activities for the impression judgments expressed by participants were measured with near-infrared spectroscopy. For each real facial picture, participants were asked to evaluate their first impressions on a scale from 'bad' to 'good' using a keyboard. The results showed that although the right dmPFC has a higher sensitivity in processing impressions, both the hemispheres of dmPFC showed a significant trend where the activation of positive impressions was higher than the negative ones. Accordingly, it is proposed that the dmPFC acts as a single mechanism responsible for delineating the processing of first impressions rather than two lateralized systems. Therefore, a 'positivity dominance hypothesis' is also proposed, which states that dmPFC in both hemispheres have a higher sensitivity and priority for positive impressions than negative ones. The present study provides valuable findings with respect to the role of the dmPFC in the processes of first impression formation. PMID:27035730

  11. Influence of temperature on the precision of noninvasive glucose sensing by near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Liu, Rong; Chen, Wenliang; Chen, Yun; Xu, Kexin

    2008-02-01

    The use of near-infrared spectroscopy for the monitoring of blood glucose concentration is limited by many ambiguous factors, which leads to the prediction precision is not satisfied. Due to the weak interested signal and the difficulty to quantify the physiological noise directly, the absorbance induced by glucose concentration and temperature was analyzed based on Beer-Lambert Law and displacement between glucose and water. Then the transmittance of glucose aqueous solution in different temperatures was measured by spectrometer to investigate the influence of glucose concentration and temperature. As it's difficult to distinguish the influence of temperature from the diffuse reflectance, the Monte Carlo simulation was used to compute the light intensity induced by the change in glucose concentration and physiological temperature. Finally, the influence of actual physiological temperature on the prediction model of glucose concentration was estimated based on the oral glucose tolerance tests of two diabetics. The result showed that, near the normal physiological temperature, the intensity of diffuse reflectance caused by -0.1 °C change in temperature was equivalent to that caused by 2.7 mmol/L change in glucose concentration. Moreover, the proportion of prediction error induced by temperature to the total error was more than 50%.

  12. Application of near-infrared spectroscopy to measurement of hemodynamic signals accompanying stimulated saliva secretion

    NASA Astrophysics Data System (ADS)

    Sato, Hiroki; Obata, Akiko N.; Moda, Ichiro; Ozaki, Kazutaka; Yasuhara, Takaomi; Yamamoto, Yukari; Kiguchi, Masashi; Maki, Atsushi; Kubota, Kisou; Koizumi, Hideaki

    2011-04-01

    We aim to test the feasibility of using near-infrared spectroscopy (NIRS) for indirect measurement of human saliva secretion in response to taste stimuli for potential application to organoleptic testing. We use an NIRS system to measure extracranial hemodynamics (Hb-signals around the temples) of healthy participants when taste stimuli are taken in their mouths. First, the Hb-signals and volume of expelled saliva (stimulated by distilled-water or sucrose-solution intake) are simultaneously measured and large Hb-signal changes in response to the taste stimuli (Hb-responses) are found. Statistical analysis show that both the Hb response and saliva volume are larger for the sucrose solution than for the distilled water with a significant correlation between them (r = 0.81). The effects of swallowing on the Hb-signals are investigated. Similar Hb responses, differing from the sucrose solution and distilled water, are obtained even though the participants swallow the mouth contents. Finally, functional magnetic resonance imaging is used to identify possible sources of the Hb signals corresponding to salivation. Statistical analysis indicates similar responses in the extracranial regions, mainly around the middle meningeal artery. In conclusion, the identified correlation between extracranial hemodynamics and the saliva volume suggests that NIRS is applicable to the measurement of hemodynamic signals accompanying stimulated saliva secretion.

  13. Antioxidant capacity of different cheeses: Affecting factors and prediction by near infrared spectroscopy.

    PubMed

    Revilla, I; González-Martín, M I; Vivar-Quintana, A M; Blanco-López, M A; Lobos-Ortega, I A; Hernández-Hierro, J M

    2016-07-01

    In this study, we analyzed antioxidant capacity of 224 cheese samples prepared using 16 varied mixtures of milk from cows, ewes, and goats, in 2 manufacturing seasons (winter and summer), and over 6mo of ripening. Antioxidant capacity was evaluated using the spectrophotometric 2,2-azinobis(3-ethylenebenzothiazoline-6-sulfonic acid) (ABTS) method. Total antioxidant capacity was significantly correlated with season of manufacturing and time of ripening but not with animal species providing the milk. Moreover, statistically significant correlations between the total antioxidant capacity and retinol (r=0.399), fat percentage (r=0.308), protein percentage (r=0.366), K (r=0.385), Mg (r=0.312), Na (r=0.432), and P (0.272) were observed. We evaluated the use of near infrared spectroscopy technology, together with the use of a remote reflectance fiber-optic probe, to predict the antioxidant capacity of cheese samples. The model generated allowed us to predict antioxidant capacity in unknown cheeses of different compositions and ripening times. PMID:27085414

  14. Detection of Cell Wall Chemical Variation in Zea Mays Mutants Using Near-Infrared Spectroscopy

    SciTech Connect

    Buyck, N.; Thomas, S.

    2001-01-01

    Corn stover is regarded as the prime candidate feedstock material for commercial biomass conversion in the United States. Variations in chemical composition of Zea mays cell walls can affect biomass conversion process yields and economics. Mutant lines were constructed by activating a Mu transposon system. The cell wall chemical composition of 48 mutant families was characterized using near-infrared (NIR) spectroscopy. NIR data were analyzed using a multivariate statistical analysis technique called Principal Component Analysis (PCA). PCA of the NIR data from 349 maize leaf samples reveals 57 individuals as outliers on one or more of six Principal Components (PCs) at the 95% confidence interval. Of these, 19 individuals from 16 families are outliers on either PC3 (9% of the variation) or PC6 (1% of the variation), the two PCs that contain information about cell wall polymers. Those individuals for which altered cell wall chemistry is confirmed with wet chemical analysis will then be subjected to fermentation analysis to determine whether or not biomass conversion process kinetics, yields and/or economics are significantly affected. Those mutants that provide indications for a decrease in process cost will be pursued further to identify the gene(s) responsible for the observed changes in cell wall composition and associated changes in process economics. These genes will eventually be incorporated into maize breeding programs directed at the development of a truly dual use crop.

  15. Detection of UV-induced cyclobutane pyrimidine dimers by near-infrared spectroscopy and aquaphotomics

    PubMed Central

    Goto, Noriko; Bazar, Gyorgy; Kovacs, Zoltan; Kunisada, Makoto; Morita, Hiroyuki; Kizaki, Seiichiro; Sugiyama, Hiroshi; Tsenkova, Roumiana; Nishigori, Chikako

    2015-01-01

    Ultraviolet (UV) radiation causes cellular DNA damage, among which cyclobutane pyrimidine dimers (CPDs) are responsible for a variety of genetic mutations. Although several approaches have been developed for detection of CPDs, conventional methods require time-consuming steps. Aquaphotomics, a new approach based on near-infrared spectroscopy (NIRS) and multivariate analysis that determines interactions between water and other components of the solution, has become an effective method for qualitative and quantitative parameters measurement in the solutions. NIR spectral patterns of UVC-irradiated and nonirradiated DNA solutions were evaluated using aquaphotomics for detection of UV-induced CPDs. Groups of UV-irradiated and nonirradiated DNA samples were classified (87.5% accuracy) by soft independent modeling of class analogy (SIMCA). A precise regression model calculated from NIR water spectral patterns based on UVC doses (r Val = 0.9457) and the concentration of cis-syn cyclobutane thymine dimers (cis-syn T<>Ts; r Val = 0.9993) was developed using partial least squares regression (PLSR), while taking advantage of water spectral patterns, particularly around 1400–1500 nm. Our results suggested that, in contrast to DNA, the formation of cis-syn T<>Ts increased the strongly hydrogen bonded water. Additionally, NIRS could qualitatively and quantitatively detect cis-syn T<>Ts in isolated DNA aqueous solutions upon UVC exposure. PMID:26133899

  16. Fecal near infrared spectroscopy to discriminate physiological status in giant pandas.

    PubMed

    Wiedower, Erin E; Kouba, Andrew J; Vance, Carrie K; Hansen, Rachel L; Stuth, Jerry W; Tolleson, Douglas R

    2012-01-01

    Giant panda (Ailuropoda melanoleuca) monitoring and research often require accurate estimates of population size and density. However, obtaining these estimates has been challenging. Innovative technologies, such as fecal near infrared reflectance spectroscopy (FNIRS), may be used to differentiate between sex, age class, and reproductive status as has been shown for several other species. The objective of this study was to determine if FNIRS could be similarly used for giant panda physiological discriminations. Based on samples from captive animals in four U.S. zoos, FNIRS calibrations correctly identified 78% of samples from adult males, 81% from adult females, 85% from adults, 89% from juveniles, 75% from pregnant and 70% from non-pregnant females. However, diet had an impact on the success of the calibrations. When diet was controlled for plant part such that "leaf only" feces were evaluated, FNIRS calibrations correctly identified 93% of samples from adult males and 95% from adult females. These data show that FNIRS has the potential to differentiate between the sex, age class, and reproductive status in the giant panda and may be applicable for surveying wild populations. PMID:22719982

  17. Functional near-infrared spectroscopy for adaptive human-computer interfaces

    NASA Astrophysics Data System (ADS)

    Yuksel, Beste F.; Peck, Evan M.; Afergan, Daniel; Hincks, Samuel W.; Shibata, Tomoki; Kainerstorfer, Jana; Tgavalekos, Kristen; Sassaroli, Angelo; Fantini, Sergio; Jacob, Robert J. K.

    2015-03-01

    We present a brain-computer interface (BCI) that detects, analyzes and responds to user cognitive state in real-time using machine learning classifications of functional near-infrared spectroscopy (fNIRS) data. Our work is aimed at increasing the narrow communication bandwidth between the human and computer by implicitly measuring users' cognitive state without any additional effort on the part of the user. Traditionally, BCIs have been designed to explicitly send signals as the primary input. However, such systems are usually designed for people with severe motor disabilities and are too slow and inaccurate for the general population. In this paper, we demonstrate with previous work1 that a BCI that implicitly measures cognitive workload can improve user performance and awareness compared to a control condition by adapting to user cognitive state in real-time. We also discuss some of the other applications we have used in this field to measure and respond to cognitive states such as cognitive workload, multitasking, and user preference.

  18. Quantitative analysis and detection of adulteration in pork using near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Fan, Yuxia; Cheng, Fang; Xie, Lijuan

    2010-04-01

    Authenticity is an important food quality criterion. Rapid methods for confirming authenticity or detecting adulteration are increasingly demanded by food processors and consumers. Near infrared (NIR) spectroscopy has been used to detect economic adulteration in pork . Pork samples were adulterated with liver and chicken in 10% increments. Prediction and quantitative analysis were done using raw data and pretreatment spectra. The optimal prediction result was achieved by partial least aquares(PLS) regression with standard normal variate(SNV) pretreatment for pork adulterated with liver samples, and the correlation coefficient(R value), the root mean square error of calibration(RMSEC) and the root mean square error of prediction (RMSEP) were 0.97706, 0.0673 and 0.0732, respectively. The best model for pork meat adulterated with chicken samples was obtained by PLS with the raw spectra, and the correlation coefficient(R value), RMSEP and RMSEC were 0.98614, 0.0525, and 0.122, respectively. The result shows that NIR technology can be successfully used to detect adulteration in pork meat adulterated with liver and chicken.

  19. Quality control and assurance in functional near infrared spectroscopy (fNIRS) experimentation

    NASA Astrophysics Data System (ADS)

    Orihuela-Espina, F.; Leff, D. R.; James, D. R. C.; Darzi, A. W.; Yang, G. Z.

    2010-07-01

    Functional near infrared spectroscopy (fNIRS) is a rapidly developing neuroimaging modality for exploring cortical brain behaviour. Despite recent advances, the quality of fNIRS experimentation may be compromised in several ways: firstly, by altering the optical properties of the tissues encountered in the path of light; secondly, through adulteration of the recovered biological signals (noise) and finally, by modulating neural activity. Currently, there is no systematic way to guide the researcher regarding these factors when planning fNIRS studies. Conclusions extracted from fNIRS data will only be robust if appropriate methodology and analysis in accordance with the research question under investigation are employed. In order to address these issues and facilitate the quality control process, a taxonomy of factors influencing fNIRS data have been established. For each factor, a detailed description is provided and previous solutions are reviewed. Finally, a series of evidence-based recommendations are made with the aim of improving consistency and quality of fNIRS research.

  20. Determination of soil content in chlordecone (organochlorine pesticide) using near infrared reflectance spectroscopy (NIRS).

    PubMed

    Brunet, Didier; Woignier, Thierry; Lesueur-Jannoyer, Magalie; Achard, Raphaël; Rangon, Luc; Barthès, Bernard G

    2009-11-01

    Chlordecone is a toxic organochlorine insecticide that was used in banana plantations until 1993 in the French West Indies. This study aimed at assessing the potential of near infrared reflectance spectroscopy (NIRS) for determining chlordecone content in Andosols, Nitisols and Ferralsols from Martinique. Using partial least square regression, chlordecone content conventionally determined through gas chromatography-mass spectrometry could be correctly predicted by NIRS (Q(2) = 0.75, R(2) = 0.82 for the total set), especially for samples with chlordecone content <12 mg kg(-1) or when the sample set was rather homogeneous (Q(2) = 0.91, R(2) = 0.82 for the Andosols). Conventional measures and NIRS predictions were poorly correlated for chlordecone content >12 mg kg(-1), nevertheless ca. 80% samples were correctly predicted when the set was divided into three or four classes of chlordecone content. Thus NIRS could be considered a time- and cost-effective method for characterising soil contamination by chlordecone. PMID:19493598

  1. Optical system for tablet variety discrimination using visible/near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Shao, Yongni; He, Yong; Hu, Xingyue

    2007-12-01

    An optical system based on visible/near-infrared spectroscopy (Vis/NIRS) for variety discrimination of ginkgo (Ginkgo biloba L.) tablets was developed. This system consisted of a light source, beam splitter system, sample chamber, optical detector (diffuse reflection detector), and data collection. The tablet varieties used in the research include Da na kang, Xin bang, Tian bao ning, Yi kang, Hua na xing, Dou le, Lv yuan, Hai wang, and Ji yao. All samples (n=270) were scanned in the Vis/NIR region between 325 and 1075 nm using a spectrograph. The chemometrics method of principal component artificial neural network (PC-ANN) was used to establish discrimination models of them. In PC-ANN models, the scores of the principal components were chosen as the input nodes for the input layer of ANN, and the best discrimination rate of 91.1% was reached. Principal component analysis was also executed to select several optimal wavelengths based on loading values. Wavelengths at 481, 458, 466, 570, 1000, 662, and 400 nm were then used as the input data of stepwise multiple linear regression, the regression equation of ginkgo tablets was obtained, and the discrimination rate was researched 84.4%. The results indicated that this optical system could be applied to discriminating ginkgo (Ginkgo biloba L.) tablets, and it supplied a new method for fast ginkgo tablet variety discrimination.

  2. Evaluating the Molecular Interaction of Organic Liquid Mixtures Using Near-Infrared Spectroscopy.

    PubMed

    Xiong, Zhixin; Pfeifer, Frank; Siesler, Heinz W

    2016-04-01

    The near-infrared transmission spectra of two organic liquid three-component systems of variable compositions were investigated in detail. To evaluate the interaction of the different components in the two systems the experimental spectra of the pure components were compared to mathematically constructed "pure component" spectra. Though usually the correlation coefficient (CC) and Manhattan distance (MD) are used to measure the similarity of spectra, in the present investigations principal component analysis (PCA) was found to be a more effective tool to investigate the difference between these spectra and derive parameters characterizing the interaction between the different components. Thus, PC scores for the two types of spectra established some distinct patterns which clearly expressed their differences. For a three-dimensional coordinate system of selected principal components, the Euclidean distances between the mathematically constructed and the experimental spectra of the pure components were calculated. Finally, the mean values of the distances for each component provided indices to rank the interaction of the components in the mixtures. Thus, the results offer a convenient approach that can quantitatively evaluate the molecular interactions of the individual components in organic liquid mixtures by various spectroscopies. PMID:26928223

  3. Fecal Near Infrared Spectroscopy to Discriminate Physiological Status in Giant Pandas

    PubMed Central

    Wiedower, Erin E.; Kouba, Andrew J.; Vance, Carrie K.; Hansen, Rachel L.; Tolleson, Douglas R.

    2012-01-01

    Giant panda (Ailuropoda melanoleuca) monitoring and research often require accurate estimates of population size and density. However, obtaining these estimates has been challenging. Innovative technologies, such as fecal near infrared reflectance spectroscopy (FNIRS), may be used to differentiate between sex, age class, and reproductive status as has been shown for several other species. The objective of this study was to determine if FNIRS could be similarly used for giant panda physiological discriminations. Based on samples from captive animals in four U.S. zoos, FNIRS calibrations correctly identified 78% of samples from adult males, 81% from adult females, 85% from adults, 89% from juveniles, 75% from pregnant and 70% from non-pregnant females. However, diet had an impact on the success of the calibrations. When diet was controlled for plant part such that “leaf only” feces were evaluated, FNIRS calibrations correctly identified 93% of samples from adult males and 95% from adult females. These data show that FNIRS has the potential to differentiate between the sex, age class, and reproductive status in the giant panda and may be applicable for surveying wild populations. PMID:22719982

  4. Characterizing and Authenticating Montilla-Moriles PDO Vinegars Using Near Infrared Reflectance Spectroscopy (NIRS) Technology

    PubMed Central

    De la Haba, María-José; Arias, Mar; Ramírez, Pilar; López, María-Isabel; Sánchez, María-Teresa

    2014-01-01

    This study assessed the potential of near infrared (NIR) spectroscopy as a non-destructive method for characterizing Protected Designation of Origin (PDO) “Vinagres de Montilla-Moriles” wine vinegars and for classifying them as a function of the manufacturing process used. Three spectrophotometers were evaluated for this purpose: two monochromator instruments (Foss NIRSystems 6500 SY-I and Foss NIRSystems 6500 SY-II; spectral range 400–2,500 nm in both cases) and a diode-array instrument (Corona 45 VIS/NIR; spectral range 380–1,700 nm). A total of 70 samples were used to predict major chemical quality parameters (total acidity, fixed acidity, volatile acidity, pH, dry extract, ash, acetoin, methanol, total polyphenols, color (tonality and intensity), and alcohol content), and to construct models for the classification of vinegars as a function of the manufacturing method used. The results obtained indicate that this non-invasive technology can be used successfully by the vinegar industry and by PDO regulators for the routine analysis of vinegars in order to authenticate them and to detect potential fraud. Slightly better results were achieved with the two monochromator instruments. The findings also highlight the potential of these NIR instruments for predicting the manufacturing process used, this being of particular value for the industrial authentication of traditional wine vinegars. PMID:24561402

  5. Continuous correction of differential path length factor in near-infrared spectroscopy.

    PubMed

    Talukdar, Tanveer; Moore, Jason H; Diamond, Solomon G

    2013-05-01

    In continuous-wave near-infrared spectroscopy (CW-NIRS), changes in the concentration of oxyhemoglobin and deoxyhemoglobin can be calculated by solving a set of linear equations from the modified Beer-Lambert Law. Cross-talk error in the calculated hemodynamics can arise from inaccurate knowledge of the wavelength-dependent differential path length factor (DPF). We apply the extended Kalman filter (EKF) with a dynamical systems model to calculate relative concentration changes in oxy- and deoxyhemoglobin while simultaneously estimating relative changes in DPF. Results from simulated and experimental CW-NIRS data are compared with results from a weighted least squares (WLSQ) method. The EKF method was found to effectively correct for artificially introduced errors in DPF and to reduce the cross-talk error in simulation. With experimental CW-NIRS data, the hemodynamic estimates from EKF differ significantly from the WLSQ (p < 0.001). The cross-correlations among residuals at different wavelengths were found to be significantly reduced by the EKF method compared to WLSQ in three physiologically relevant spectral bands 0.04 to 0.15 Hz, 0.15 to 0.4 Hz and 0.4 to 2.0 Hz (p < 0.001). This observed reduction in residual cross-correlation is consistent with reduced cross-talk error in the hemodynamic estimates from the proposed EKF method. PMID:23640027

  6. A review on continuous wave functional near-infrared spectroscopy and imaging instrumentation and methodology.

    PubMed

    Scholkmann, Felix; Kleiser, Stefan; Metz, Andreas Jaakko; Zimmermann, Raphael; Mata Pavia, Juan; Wolf, Ursula; Wolf, Martin

    2014-01-15

    This year marks the 20th anniversary of functional near-infrared spectroscopy and imaging (fNIRS/fNIRI). As the vast majority of commercial instruments developed until now are based on continuous wave technology, the aim of this publication is to review the current state of instrumentation and methodology of continuous wave fNIRI. For this purpose we provide an overview of the commercially available instruments and address instrumental aspects such as light sources, detectors and sensor arrangements. Methodological aspects, algorithms to calculate the concentrations of oxy- and deoxyhemoglobin and approaches for data analysis are also reviewed. From the single-location measurements of the early years, instrumentation has progressed to imaging initially in two dimensions (topography) and then three (tomography). The methods of analysis have also changed tremendously, from the simple modified Beer-Lambert law to sophisticated image reconstruction and data analysis methods used today. Due to these advances, fNIRI has become a modality that is widely used in neuroscience research and several manufacturers provide commercial instrumentation. It seems likely that fNIRI will become a clinical tool in the foreseeable future, which will enable diagnosis in single subjects. PMID:23684868

  7. Continuous correction of differential path length factor in near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Talukdar, Tanveer; Moore, Jason H.; Diamond, Solomon G.

    2013-05-01

    In continuous-wave near-infrared spectroscopy (CW-NIRS), changes in the concentration of oxyhemoglobin and deoxyhemoglobin can be calculated by solving a set of linear equations from the modified Beer-Lambert Law. Cross-talk error in the calculated hemodynamics can arise from inaccurate knowledge of the wavelength-dependent differential path length factor (DPF). We apply the extended Kalman filter (EKF) with a dynamical systems model to calculate relative concentration changes in oxy- and deoxyhemoglobin while simultaneously estimating relative changes in DPF. Results from simulated and experimental CW-NIRS data are compared with results from a weighted least squares (WLSQ) method. The EKF method was found to effectively correct for artificially introduced errors in DPF and to reduce the cross-talk error in simulation. With experimental CW-NIRS data, the hemodynamic estimates from EKF differ significantly from the WLSQ (p<0.001). The cross-correlations among residuals at different wavelengths were found to be significantly reduced by the EKF method compared to WLSQ in three physiologically relevant spectral bands 0.04 to 0.15 Hz, 0.15 to 0.4 Hz and 0.4 to 2.0 Hz (p<0.001). This observed reduction in residual cross-correlation is consistent with reduced cross-talk error in the hemodynamic estimates from the proposed EKF method.

  8. Near-infrared spectroscopy of image clarity perception in the human brain

    NASA Astrophysics Data System (ADS)

    Lugo, J. E.; Habak, C.; Doti, Rafael; Faubert, Jocelyn

    2014-09-01

    The perception of blur in humans is intrinsic to our visual system, and dioptric power can improve clarity in many cases. This was evaluated experimentally to establish the best correction with dioptric power shifts. We used Near Infrared Spectroscopy (NIRS) to measure Oxy-, Deoxy- and Total-hemoglobin concentration changes in the brain while viewing images and reading a Snellen chart. Participants were tested with their usual correction (no diopter power shift (0 D)), with a 0.25 diopter power shift (0.25 D), and with a 0.5 diopter power shift (0.5 D). The concept of Approximate Entropy (AE) was applied to quantify the regularity of these hemoglobin time series of finite length. AE computations are based on the likelihood that similar templates in a time series remain similar on the next incremental comparison, so that time series with large AE have high irregular fluctuation. We found that the dioptric power shift eliciting the highest AE indicates the clearest visual condition for subjects. This technique may impact the current way in which ophthalmic lenses are prescribed.

  9. Development of motion resistant instrumentation for ambulatory near-infrared spectroscopy

    PubMed Central

    Zhang, Quan; Yan, Xiangguo; Strangman, Gary E.

    2011-01-01

    Ambulatory near-infrared spectroscopy (aNIRS) enables recording of systemic or tissue-specific hemodynamics and oxygenation during a person's normal activities. It has particular potential for the diagnosis and management of health problems with unpredictable and transient hemodynamic symptoms, or medical conditions requiring continuous, long-duration monitoring. aNIRS is also needed in conditions where regular monitoring or imaging cannot be applied, including remote environments such as during spaceflight or at high altitude. One key to the successful application of aNIRS is reducing the impact of motion artifacts in aNIRS recordings. In this paper, we describe the development of a novel prototype aNIRS monitor, called NINscan, and our efforts to reduce motion artifacts in aNIRS monitoring. Powered by 2 AA size batteries and weighting 350 g, NINscan records NIRS, ECG, respiration, and acceleration for up to 14 h at a 250 Hz sampling rate. The system's performance and resistance to motion is demonstrated by long term quantitative phantom tests, Valsalva maneuver tests, and multiparameter monitoring during parabolic flight and high altitude hiking. To the best of our knowledge, this is the first report of multiparameter aNIRS monitoring and its application in parabolic flight. PMID:21895335

  10. Quantification of ischemic muscle deoxygenation by near infrared time-resolved spectroscopy

    NASA Astrophysics Data System (ADS)

    Hamaoka, Takatumi; Katsumura, Toshihito; Murase, Norio; Nishio, Shinya; Osada, Takuya; Sako, Takayuki; Higuchi, Hiroyuki; Kurosawa, Yuko; Shimomitsu, Teruichi; Miwa, Mitsuharu; Chance, Britton

    2000-01-01

    The purpose of this study was to quantify muscle deoxygenation in human skeletal muscles using near infrared time-resolved spectroscopy (NIRTRS) and compare NIRTRS indicators and blood saturation. The forearm muscles of five healthy males (aged 27 - 32 yrs.) were monitored for changes in hemoglobin saturation (SO2) during 12 min of arterial occlusion and recovery. SO2 was determined by measuring the temporal profile of photon diffusion at 780 and 830 nm using NIRTRS, and was defined as SO2-TRS. Venous blood samples were also obtained for measurements of SvO2, and PvO2. Interstitial PO2(PintO2) was monitored by placing an O2 electrode directly into the muscle tissue. Upon the initiation of occlusion, all parameters fell progressively until reaching a plateau in the latter half of occlusion. It was observed at the end of occlusion that SO2-TRS (24.1 +/- 5.6%) agreed with SvO2 (26.2 +/- 6.4) and that PintO2 (14.7 +/- 1.0 Torr) agreed with PvO2 (17.3 +/- 2.2 Torr). The resting O2 store (oxygenated hemoglobin) and O2 consumption rate were 290 (mu) M and 0.82 (mu) Ms-1, respectively, values which reasonably agree with the reported results. These results indicate that there was no O2 gradient between vessels and interstisium at the end of occlusion.

  11. The usefulness of near-infrared spectroscopy in the anesthetic management of endovascular aortic aneurysm repair.

    PubMed

    Wakimoto, Masahiro M; Kadosaki, Mamoru; Nagata, Hirofumi; Suzuki, Kenji S

    2012-12-01

    Near-infrared spectroscopy (NIRS) may be a useful method for monitoring the regional oxygen saturation (rSO(2)) of the lower extremity during endovascular aortic repair. Eighteen patients with thoracic descending and/or abdominal aortic aneurysm were enrolled in this study. NIRS probes were placed bilaterally on the calves. Muscular rSO(2) (mrSO(2)) was monitored every 30 s throughout the operation. In the leg in which the femoral artery was clamped, mrSO(2) values were selected at 3 or 4 points-just before clamping (control value), 30 min after clamping, 10 min after the first declamping, and 10 min after the second declamping following repair of the femoral artery, if necessary. In all patients, mrSO(2) decreased significantly during clamping, from 64 ± 11 % (mean ± SD) of the control value to 32 ± 15 %. After declamping, mrSO(2) recovered to 69 ± 14 % of the control value in 16 patients. In the 2 other patients, however, mrSO(2) did not recover after the first declamping, because of femoral artery dissection. After additional repair, mrSO(2) recovered quickly to the control value. These data suggested NIRS may objectively and quantitatively reflect oxygenation of the lower extremities, and may indicate an ischemic event that needs additional repair during endovascular aortic repair. PMID:22733429

  12. Anatomical guidance for functional near-infrared spectroscopy: AtlasViewer tutorial

    PubMed Central

    Aasted, Christopher M.; Yücel, Meryem A.; Cooper, Robert J.; Dubb, Jay; Tsuzuki, Daisuke; Becerra, Lino; Petkov, Mike P.; Borsook, David; Dan, Ippeita; Boas, David A.

    2015-01-01

    Abstract. Functional near-infrared spectroscopy (fNIRS) is an optical imaging method that is used to noninvasively measure cerebral hemoglobin concentration changes induced by brain activation. Using structural guidance in fNIRS research enhances interpretation of results and facilitates making comparisons between studies. AtlasViewer is an open-source software package we have developed that incorporates multiple spatial registration tools to enable structural guidance in the interpretation of fNIRS studies. We introduce the reader to the layout of the AtlasViewer graphical user interface, the folder structure, and user files required in the creation of fNIRS probes containing sources and detectors registered to desired locations on the head, evaluating probe fabrication error and intersubject probe placement variability, and different procedures for estimating measurement sensitivity to different brain regions as well as image reconstruction performance. Further, we detail how AtlasViewer provides a generic head atlas for guiding interpretation of fNIRS results, but also permits users to provide subject-specific head anatomies to interpret their results. We anticipate that AtlasViewer will be a valuable tool in improving the anatomical interpretation of fNIRS studies. PMID:26157991

  13. Optimized multimodal functional magnetic resonance imaging/near-infrared spectroscopy probe for ultrahigh-resolution mapping.

    PubMed

    Hocke, Lia Maria; Cayetano, Kenroy; Tong, Yunjie; Frederick, Blaise

    2015-10-01

    Functional near-infrared spectroscopy (fNIRS) is an increasingly important noninvasive method in neuroscience due to its high temporal resolution and ability to independently measure oxy- and deoxy-hemoglobin. However, the relatively low spatial resolution of fNIRS makes it difficult to relate this signal to underlying anatomy. Simultaneous functional magnetic resonance imaging (fMRI) can complement fNIRS with superior spatial resolution and the ability to image the entire brain, providing additional information to improve fNIRS localization. However, current simultaneous fMRI/fNIRS acquisition methods are not optimal, due to the poor physical compatibility of existing MR coils and fNIRS optodes. Here, we present a technique to manufacture a true multimodal fMRI/fNIRS probe in which both modalities can be used with maximal sensitivity. To achieve this, we designed custom MR coils with integral fNIRS optodes using three-dimensional printing. This multimodal probe can be used to optimize spatial ([Formula: see text]) and temporal resolution (2.5 Hz) of fMRI, and it provides maximal MRI sensitivity, while allowing for high flexibility in the location and density of fNIRS optodes within the area of interest. Phantom and human data are shown to confirm the improvement in sensitivity in both modalities. This probe shows promise for addressing fundamental questions of the relation of fNIRS to physiology. PMID:26668816

  14. Development of motion resistant instrumentation for ambulatory near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Quan; Yan, Xiangguo; Strangman, Gary E.

    2011-08-01

    Ambulatory near-infrared spectroscopy (aNIRS) enables recording of systemic or tissue-specific hemodynamics and oxygenation during a person's normal activities. It has particular potential for the diagnosis and management of health problems with unpredictable and transient hemodynamic symptoms, or medical conditions requiring continuous, long-duration monitoring. aNIRS is also needed in conditions where regular monitoring or imaging cannot be applied, including remote environments such as during spaceflight or at high altitude. One key to the successful application of aNIRS is reducing the impact of motion artifacts in aNIRS recordings. In this paper, we describe the development of a novel prototype aNIRS monitor, called NINscan, and our efforts to reduce motion artifacts in aNIRS monitoring. Powered by 2 AA size batteries and weighting 350 g, NINscan records NIRS, ECG, respiration, and acceleration for up to 14 h at a 250 Hz sampling rate. The system's performance and resistance to motion is demonstrated by long term quantitative phantom tests, Valsalva maneuver tests, and multiparameter monitoring during parabolic flight and high altitude hiking. To the best of our knowledge, this is the first report of multiparameter aNIRS monitoring and its application in parabolic flight.

  15. Time-resolved fluorescence polarization spectroscopy of visible and near infrared dyes in picosecond dynamics

    NASA Astrophysics Data System (ADS)

    Pu, Yang; Alfano, Robert R.

    2015-03-01

    Near-infrared (NIR) dyes absorb and emit light within the range from 700 to 900 nm have several benefits in biological studies for one- and/or two-photon excitation for deeper penetration of tissues. These molecules undergo vibrational and rotational motion in the relaxation of the excited electronic states, Due to the less than ideal anisotropy behavior of NIR dyes stemming from the fluorophores elongated structures and short fluorescence lifetime in picosecond range, no significant efforts have been made to recognize the theory of these dyes in time-resolved polarization dynamics. In this study, the depolarization of the fluorescence due to emission from rotational deactivation in solution will be measured with the excitation of a linearly polarized femtosecond laser pulse and a streak camera. The theory, experiment and application of the ultrafast fluorescence polarization dynamics and anisotropy are illustrated with examples of two of the most important medical based dyes. One is NIR dye, namely Indocyanine Green (ICG) and is compared with Fluorescein which is in visible range with much longer lifetime. A set of first-order linear differential equations was developed to model fluorescence polarization dynamics of NIR dye in picosecond range. Using this model, the important parameters of ultrafast polarization spectroscopy were identified: risetime, initial time, fluorescence lifetime, and rotation times.

  16. Reliability of telemetric electromyography and near-infrared spectroscopy during high-intensity resistance exercise.

    PubMed

    Scott, Brendan R; Slattery, Katie M; Sculley, Dean V; Lockie, Robert G; Dascombe, Ben J

    2014-10-01

    This study quantified the inter- and intra-test reliability of telemetric surface electromyography (EMG) and near infrared spectroscopy (NIRS) during resistance exercise. Twelve well-trained young men performed high-intensity back squat exercise (12 sets at 70-90% 1-repetition maximum) on two occasions, during which EMG and NIRS continuously monitored muscle activation and oxygenation of the thigh muscles. Intra-test reliability for EMG and NIRS variables was generally higher than inter-test reliability. EMG median frequency variables were generally more reliable than amplitude-based variables. The reliability of EMG measures was not related to the intensity or number of repetitions performed during the set. No notable differences were evident in the reliability of EMG between different agonist muscles. NIRS-derived measures of oxyhaemoglobin, deoxyhaemoglobin and tissue saturation index were generally more reliable during single-repetition sets than multiple-repetition sets at the same intensity. Tissue saturation index was the most reliable NIRS variable. Although the reliability of the EMG and NIRS measures varied across the exercise protocol, the precise causes of this variability are not yet understood. However, it is likely that biological variation during multi-joint isotonic resistance exercise may account for some of the variation in the observed results. PMID:25127493

  17. Cortical response to categorical color perception in infants investigated by near-infrared spectroscopy

    PubMed Central

    Yang, Jiale; Kanazawa, So; Yamaguchi, Masami K.; Kuriki, Ichiro

    2016-01-01

    Perceptual color space is continuous; however, we tend to divide it into only a small number of categories. It is unclear whether categorical color perception is obtained solely through the development of the visual system or whether it is affected by language acquisition. To address this issue, we recruited prelinguistic infants (5- to 7-mo-olds) to measure changes in brain activity in relation to categorical color differences by using near-infrared spectroscopy (NIRS). We presented two sets of geometric figures to infants: One set altered in color between green and blue, and the other set altered between two different shades of green. We found a significant increase in hemodynamic responses during the between-category alternations, but not during the within-category alternations. These differences in hemodynamic response based on categorical relationship were observed only in the bilateral occipitotemporal regions, and not in the occipital region. We confirmed that categorical color differences yield behavioral differences in infants. We also observed comparable hemodynamic responses to categorical color differences in adults. The present study provided the first evidence, to our knowledge, that colors of different categories are represented differently in the visual cortex of prelinguistic infants, which implies that color categories may develop independently before language acquisition. PMID:26858441

  18. The utility of near infrared spectroscopy for age estimation of deepwater sharks

    NASA Astrophysics Data System (ADS)

    Rigby, Cassandra L.; Wedding, Brett B.; Grauf, Steve; Simpfendorfer, Colin A.

    2014-12-01

    Reliable age information is vital for effective fisheries management, yet age determinations are absent for many deepwater sharks as they cannot be aged using traditional methods of growth bands counts. An alternative approach to ageing using near infrared spectroscopy (NIRS) was investigated using dorsal fin spines, vertebrae and fin clips of three species of deepwater sharks. Ages were successfully estimated for the two dogfish, Squalus megalops and Squalus montalbani, and NIRS spectra were correlated with body size in the catshark, Asymbolus pallidus. Correlations between estimated-ages of the dogfish dorsal fin spines and their NIRS spectra were good, with S. megalops R2=0.82 and S. montalbani R2=0.73. NIRS spectra from S. megalops vertebrae and fin clips that have no visible growth bands were correlated with estimated-ages, with R2=0.89 and 0.76, respectively. NIRS has the capacity to non-lethally estimate ages from fin spines and fin clips, and thus could significantly reduce the numbers of sharks that need to be lethally sampled for ageing studies. The detection of ageing materials by NIRS in poorly calcified deepwater shark vertebrae could potentially enable ageing of this group of sharks that are vulnerable to exploitation.

  19. Irradiation dose detection of irradiated milk powder using visible and near-infrared spectroscopy and chemometrics.

    PubMed

    Kong, W W; Zhang, C; Liu, F; Gong, A P; He, Y

    2013-08-01

    The objective of this study was to examine the possibility of applying visible and near-infrared spectroscopy to the quantitative detection of irradiation dose of irradiated milk powder. A total of 150 samples were used: 100 for the calibration set and 50 for the validation set. The samples were irradiated at 5 different dose levels in the dose range 0 to 6.0 kGy. Six different pretreatment methods were compared. The prediction results of full spectra given by linear and nonlinear calibration methods suggested that Savitzky-Golay smoothing and first derivative were suitable pretreatment methods in this study. Regression coefficient analysis was applied to select effective wavelengths (EW). Less than 10 EW were selected and they were useful for portable detection instrument or sensor development. Partial least squares, extreme learning machine, and least squares support vector machine were used. The best prediction performance was achieved by the EW-extreme learning machine model with first-derivative spectra, and correlation coefficients=0.97 and root mean square error of prediction=0.844. This study provided a new approach for the fast detection of irradiation dose of milk powder. The results could be helpful for quality detection and safety monitoring of milk powder. PMID:23769357

  20. Near-Infrared Spectroscopy for Objectifying Cerebral Effects of Laser Acupuncture in Term and Preterm Neonates

    PubMed Central

    Raith, Wolfgang; Avian, Alexander; Sommer, Constanze; Koestenberger, Martin; Schmölzer, Georg M.; Urlesberger, Berndt

    2013-01-01

    Laser acupuncture (LA) becomes more and more relevant in neonates and infants. With near-infrared spectroscopy (NIRS), a continuous and noninvasive measurement of tissue oxygenation is possible. Aim was to investigate, whether the application of LA was associated with any changes in regional cerebral oxygen saturation (rcSO2) in term and preterm neonates. The study included 20 neonates (12 males, 8 females). The Large Intestine 4 acupuncture point (LI 4, Hegu) was stimulated by a microlaser needle (10 mW, 685 nm laser needle EG GmbH, Germany) for 5 minutes, bilaterally. All neonates underwent polygraphic recording during undisturbed daytime sleep, including heart rate (HR), peripheral oxygen saturation (SpO2), and measurement of nasal flow. Using NIRS, rcSO2 was measured continuously. Cerebral fractional tissue oxygen extraction (cFTOE) was calculated. We did not observe any significant changes in SpO2 and HR values during the whole observation period. However, there was a significant decrease in rcSO2 (P = 0.003) within postintervention period, accompanied by a significant increase in cFTOE (P = 0.010) in postintervention period. PMID:23762122

  1. Comparison of motion correction techniques applied to functional near-infrared spectroscopy data from children

    NASA Astrophysics Data System (ADS)

    Hu, Xiao-Su; Arredondo, Maria M.; Gomba, Megan; Confer, Nicole; DaSilva, Alexandre F.; Johnson, Timothy D.; Shalinsky, Mark; Kovelman, Ioulia

    2015-12-01

    Motion artifacts are the most significant sources of noise in the context of pediatric brain imaging designs and data analyses, especially in applications of functional near-infrared spectroscopy (fNIRS), in which it can completely affect the quality of the data acquired. Different methods have been developed to correct motion artifacts in fNIRS data, but the relative effectiveness of these methods for data from child and infant subjects (which is often found to be significantly noisier than adult data) remains largely unexplored. The issue is further complicated by the heterogeneity of fNIRS data artifacts. We compared the efficacy of the six most prevalent motion artifact correction techniques with fNIRS data acquired from children participating in a language acquisition task, including wavelet, spline interpolation, principal component analysis, moving average (MA), correlation-based signal improvement, and combination of wavelet and MA. The evaluation of five predefined metrics suggests that the MA and wavelet methods yield the best outcomes. These findings elucidate the varied nature of fNIRS data artifacts and the efficacy of artifact correction methods with pediatric populations, as well as help inform both the theory and practice of optical brain imaging analysis.

  2. 3D Multi-spectral Image-guided Near-infrared Spectroscopy using Boundary Element Method

    PubMed Central

    Srinivasan, Subhadra; Pogue, Brian W.; Paulsen, Keith D.

    2010-01-01

    Image guided (IG) Near-Infrared spectroscopy (NIRS) has the ability to provide high-resolution metabolic and vascular characterization of tissue, with clinical applications in diagnosis of breast cancer. This method is specific to multimodality imaging where tissue boundaries obtained from alternate modalities such as MRI/CT, are used for NIRS recovery. IG-NIRS is severely limited in 3D by challenges such as volumetric meshing of arbitrary anatomical shapes and computational burden encountered by existing models which use finite element method (FEM). We present an efficient and feasible alternative to FEM using boundary element method (BEM). The main advantage is the use of surface discretization which is reliable and more easily generated than volume grids in 3D and enables automation for large number of clinical data-sets. The BEM has been implemented for the diffusion equation to model light propagation in tissue. Image reconstruction based on BEM has been tested in a multi-threading environment using four processors which provides 60% improvement in computational time compared to a single processor. Spectral priors have been implemented in this framework and applied to a three-region problem with mean error of 6% in recovery of NIRS parameters. PMID:21179380

  3. Monitoring angiogenesis using a human compatible calibration for broadband near-infrared spectroscopy.

    PubMed

    Yang, Runze; Zhang, Qiong; Wu, Ying; Dunn, Jeff F

    2013-01-01

    Angiogenesis is a hallmark of many conditions, including cancer, stroke, vascular disease, diabetes, and high-altitude exposure. We have previously shown that one can study angiogenesis in animal models by using total hemoglobin (tHb) as a marker of cerebral blood volume (CBV), measured using broadband near-infrared spectroscopy (bNIRS). However, the method was not suitable for patients as global anoxia was used for the calibration. Here we determine if angiogenesis could be detected using a calibration method that could be applied to patients. CBV, as a marker of angiogenesis, is quantified in a rat cortex before and after hypoxia acclimation. Rats are acclimated at 370-mmHg pressure for three weeks, while rats in the control group are housed under the same conditions, but under normal pressure. CBV increased in each animal in the acclimation group. The mean CBV (%volume/volume) is 3.49%± 0.43% (mean ± SD) before acclimation for the experimental group, and 4.76%± 0.29% after acclimation. The CBV for the control group is 3.28%± 0.75%, and 3.09%± 0.48% for the two measurements. This demonstrates that angiogenesis can be monitored noninvasively over time using a bNIRS system with a calibration method that is compatible with human use and less stressful for studies using animals. PMID:23314579

  4. [Study on germination rate of zoysia (Zoysia japonica Steud.) seeds using near infrared reflectance spectroscopy].

    PubMed

    Liang, Xiao-Hong; Zhang, Li-Juan; Fan, Bo; Mao, Wen-Hua; Mao, Wen-Hua; Puyang, Xue-Hua; Han, Lie-Bao

    2013-10-01

    With 37 zoysia seed samples with different germination rates ranging from 58.5% to 92%, harvested in different years from 2009 to 2011 and from different locations of China, a model for determining germination rate of zoysia seeds was tried to be built by near infrared reflectance spectroscopy with quantitative partial least squares (QPLS). All the seeds samples were divided into two groups: calibration set (including 28 samples) and validation set (including 9 samples). The results showed that with the spectral range from 6 000 to 7 000 cm(-1) and 6 main components, there was a better fitting between the predictive value and true value. Determination coefficients (R2) of calibration and validation sets are 90.73% and 91.80%, the coefficients of correlation are 0.986 6 and 0.987 2, the standard errors are 9.80 and 9.47, and the average absolute errors are 7.64% and 6.98% respectively. Even with different calibration samples, the models have a high determination coefficient (R2 over building of NIR model for determining 90%), low standard errors (about 10.00) and low absolute errors (about 8.00%). The building of NIR model for determining germination rate of zoysia seeds could promote the application of high quality seeds in production. PMID:24409708

  5. Rapid quantification of stabilizing agents in single-base propellants using near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhou, Shuai; Wang, Zhiqiang; Lu, Leiming; Yin, Qiushi; Yu, Liuhua; Deng, Guodong

    2016-07-01

    The standard analytical method (gas chromatography, GC) applied for determination of stabilizing agents including diphenylamine (DPA) and N,N‧-Dimethyl carbanilide (C2) in single-base propellants always costs too much time and toxic regents, and forms harmful wastes. This study investigated the feasibility of using near infrared (NIR) spectroscopy as a fast and green substitute. The samples were partitioned into calibration and validation subsets using the joint x-y distance (SPXY) algorithm. The backward interval partial least squares (biPLS) algorithm was used for wavenumber region selection during the model development. The correlation coefficient of validation (Rval), the root mean square error of prediction (RMSEP) and the ratio of standard deviation of the validation set to standard error of prediction (RPD) of the developed models were 0.987, 0.201 and 5.29 for DPA, and 0.976, 0.227 and 6.12 for C2, separately. The repeatability of the NIR methods satisfied the requirement of the standard method. The results showed that the developed NIR models exhibited good predictive performance and repeatability, and would have a promising future in predicting stabilizing agents content of single-base propellants due to high speed, convenience and no pretreatment.

  6. Rapid identification of illegal synthetic adulterants in herbal anti-diabetic medicines using near infrared spectroscopy.

    PubMed

    Feng, Yanchun; Lei, Deqing; Hu, Changqin

    2014-05-01

    We created a rapid detection procedure for identifying herbal medicines illegally adulterated with synthetic drugs using near infrared spectroscopy. This procedure includes a reverse correlation coefficient method (RCCM) and comparison of characteristic peaks. Moreover, we made improvements to the RCCM based on new strategies for threshold settings. Any tested herbal medicine must meet two criteria to be identified with our procedure as adulterated. First, the correlation coefficient between the tested sample and the reference must be greater than the RCCM threshold. Next, the NIR spectrum of the tested sample must contain the same characteristic peaks as the reference. In this study, four pure synthetic anti-diabetic drugs (i.e., metformin, gliclazide, glibenclamide and glimepiride), 174 batches of laboratory samples and 127 batches of herbal anti-diabetic medicines were used to construct and validate the procedure. The accuracy of this procedure was greater than 80%. Our data suggest that this protocol is a rapid screening tool to identify synthetic drug adulterants in herbal medicines on the market. PMID:24566115

  7. Functional near-infrared spectroscopy to investigate hemodynamic responses to deception in the prefrontal cortex.

    PubMed

    Tian, Fenghua; Sharma, Vikrant; Kozel, F Andrew; Liu, Hanli

    2009-12-15

    Deception involves complex neural processes and correlates in the brain. Functional brain imaging techniques have been used to study and understand brain mechanisms during deception. In this study, we utilized functional near-infrared spectroscopy (fNIRS) to investigate hemodynamic responses to deception in the prefrontal cortex (PFC) at the individual level. The protocol involved a mock theft scenario that was previously used in a functional MRI (fMRI) study of detecting deception. Subjects (N=11) were instructed to steal a ring or a watch and then conceal the item that they stole. Participants then responded to visually presented questions regarding which item they took. While the subjects were answering the questions, their PFC activity was measured using fNIRS. The brain activity associated with deceptive responses demonstrated significant changes in hemoglobin concentrations with respect to the baseline, while the response of truth telling was not statistically different from baseline. The regions of greater activation induced by deception identified by fNIRS were approximately consistent with those reported by the previous fMRI study using a similar protocol. This study demonstrates that fNIRS is a promising new technique to understand hemodynamic and neural correlates of deception and thus to detect deception with the added advantages of being compact, technically easier to implement, and inexpensive compared to functional MRI. PMID:19782657

  8. Near-Infrared Spectroscopy: The New Must Have Tool in the Intensive Care Unit?

    PubMed

    Green, Michael Stuart; Sehgal, Sankalp; Tariq, Rayhan

    2016-09-01

    Standard hemodynamic monitoring such as blood pressure and pulse oximetry may only provide a crude estimation of organ perfusion in the critical care setting. Near-infrared spectroscopy (NIRS) is based on the same principle as a pulse oximeter and allows continuous noninvasive monitoring of hemoglobin oxygenation and deoxygenation and thus tissue saturation "StO2" This review aims to provide an overview of NIRS technology principles and discuss its current clinical use in the critical care setting. The study selection was performed using the PubMed database to find studies that investigated the use of NIRS in both the critical care setting and in the intensive care unit. Currently, NIRS in the critical care setting is predominantly being used for infants and neonates. A number of studies in the past decade have shown promising results for the use of NIRS in surgical/trauma intensive care units during shock management as a prognostic tool and in guiding resuscitation. It is evident that over the past 2 decades, NIRS has gone from being a laboratory fascination to an actively employed clinical tool. Even though the benefit of routine use of this technology to achieve better outcomes is still questionable, the fact that NIRS is a low-cost, noninvasive monitoring modality improves the attractiveness of the technology. However, more research may be warranted before recommending its routine use in the critical care setting. PMID:27206637

  9. Skeletal muscle hemoglobin content measured by near-infrared spectroscopy during oscillatory venous pressure variation

    NASA Astrophysics Data System (ADS)

    Marcu, Laura; Maarek, Jean-Michel I.; Bembi, Atul; Howell, Sandra

    1995-04-01

    Changes in oxidized (HbO), reduced (Hbr), and total hemoglobin (Hbt) contents were monitored by near infrared spectroscopy in human forearm skeletal muscle during oscillatory variations of the effective venous pressure. Laser diode pulses (wavelength, 775, 810, 865, 904; duration, 60 ns) were directed to the muscle by means of an optic fiber bundle and detected with a sensing fiber positioned at 1.5 cm from the emitting bundle. Sinusoidal pressure waves (frequency, 1 and 2 cycles/min; amplitude, 10-15 mm Hg) generated by a piston pump were transmitted to a sphygmomanometer cuff placed on the arm, the mean cuff pressure (Pc) being 20, 40 and 60 mm Hg. Variations of HbO, Hbr and Hbt were computed from the optical signals and processed by Fourier analysis to characterize their amplitude and phase relative to the cuff mean pressure oscillations (Posc). Oscillations of HbO, Hbr, Hbt were observed for all mean cuff pressures, the amplitude of the variations being decreased with increasing Pc. For Pc equals 20 mm Hg, the oscillations of HbO and Hbt were nearly in phase with Posc whereas the oscillation of Hbr were out of phase with HbO and Posc. Increasing Pc resulted in an increase of the phase difference between HbO and Posc, Hbr remaining out of phase with Posc. These trends could be predicted with a lumped model of the forearm vasculature, suggesting that the technique could be used to asses mechanical characteristics of vascular beds.

  10. Non-invasive diagnosis and continuous monitoring of thrombosis in clinics by near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Li, Ting; Sun, Yunglong; Chen, Xiao; Zhao, Yue; Ren, Rongrong; Liu, Mushuang

    2015-03-01

    Thrombosis became one of the most severe disease hazard to human health, and it incidence rate grows increasingly higher throughout the world. The conventional diagnosis and monitoring thrombosis mainly relied on the invasive techniques, e.g., digital subtraction angiography and blood sample analysis, and expensive and ionizing techniques, e.g., magnetic resonance angiography. And those techniques can not measure continuously. Here we reported our preliminary exploration of using near-infrared spectroscopy (NIRS) in clinical monitoring of thrombosis. 7 healthy subjects and 6 thrombosis patients at similar age participated the NIRS measurements of oxy- and deoxy- hemoglobin ([HbO2] and [Hb]) on 6 particular parts of legs. We repeated [HbO2] measurement at the same specified time each day after thrombolytic therapy for one single-leg-DVT patient, and terminated till the patient was cured and left hospital. We found that - (1) [HbO2] kept lower in thrombosis patients and [Hb] kept lower in healthy people (p<0.001) (2) [HbO2] kept increasing in the thrombosis leg but decreasing in healthy leg for the patients after thrombolytic therapy, and coincidently, [HbO2] acted consistent just when the patients were cured and left. Our study successfully extended the application of NIRS in noninvasive, continuous, and low-cost monitoring of thrombosis in clinics. Our findings showed the powerful potential of [HbO2] by NIRS in diagnosis and therapeutic effect evaluation of thrombosis.

  11. Near-Infrared Spectroscopy of V1974 Cygni 1992: New Coronal Emission Lines in Classical Novae

    NASA Astrophysics Data System (ADS)

    Wagner, R. Mark; Depoy, D. L.

    1996-08-01

    The near-infrared (1.2-2.4 μm) spectrum of V1974 Cygni (Nova Cygni 1992) was observed on 1993 May 2 at a spectral resolution of 570 using the Ohio State University Infrared Imager/Spectrometer on the Perkins 1.8 m telescope. In agreement with previous infrared spectra of novae and V1974 Cyg in particular, we find emission lines of [Al IX], [Ca VIII], [Si VI], and [S IX] present in our spectra. However, contemporaneously with the appearance of enhanced soft X-ray emission observed by ROSAT in early 1993, we report the discovery of infrared coronal lines arising from ions not previously observed in classical novae. These include [P VIII] 1.737 μm, [P VII] 1.377 μm, [Si X] 1.430 μm, [S XI] 1.395 μm, [Ti VI] 1.715 μm, and possibly [Cr XI] 1.550 μm and [Ti x] 1.332 μm. Optical spectroscopy confirms the high degree of ionization and gives Te ≃ 20,000 K in the [Fe VII] region. Photoionization from the hot white dwarf remnant can account for the high degree of ionization and relatively low excitation temperature of the ejecta. Our discovery of phosphorus in the ejecta when combined with the results of recent hydrodynamic studies of accretion onto white dwarfs suggests that the white dwarf in V1974 Cyg 1992 must be extremely massive.

  12. Using near infrared spectroscopy to classify soybean oil according to expiration date.

    PubMed

    da Costa, Gean Bezerra; Fernandes, David Douglas Sousa; Gomes, Adriano A; de Almeida, Valber Elias; Veras, Germano

    2016-04-01

    A rapid and non-destructive methodology is proposed for the screening of edible vegetable oils according to conservation state expiration date employing near infrared (NIR) spectroscopy and chemometric tools. A total of fifty samples of soybean vegetable oil, of different brands andlots, were used in this study; these included thirty expired and twenty non-expired samples. The oil oxidation was measured by peroxide index. NIR spectra were employed in raw form and preprocessed by offset baseline correction and Savitzky-Golay derivative procedure, followed by PCA exploratory analysis, which showed that NIR spectra would be suitable for the classification task of soybean oil samples. The classification models were based in SPA-LDA (Linear Discriminant Analysis coupled with Successive Projection Algorithm) and PLS-DA (Discriminant Analysis by Partial Least Squares). The set of samples (50) was partitioned into two groups of training (35 samples: 15 non-expired and 20 expired) and test samples (15 samples 5 non-expired and 10 expired) using sample-selection approaches: (i) Kennard-Stone, (ii) Duplex, and (iii) Random, in order to evaluate the robustness of the models. The obtained results for the independent test set (in terms of correct classification rate) were 96% and 98% for SPA-LDA and PLS-DA, respectively, indicating that the NIR spectra can be used as an alternative to evaluate the degree of oxidation of soybean oil samples. PMID:26593525

  13. Application of near-infrared spectroscopy to measurement of hemodynamic signals accompanying stimulated saliva secretion.

    PubMed

    Sato, Hiroki; Obata, Akiko N; Moda, Ichiro; Ozaki, Kazutaka; Yasuhara, Takaomi; Yamamoto, Yukari; Kiguchi, Masashi; Maki, Atsushi; Kubota, Kisou; Koizumi, Hideaki

    2011-04-01

    We aim to test the feasibility of using near-infrared spectroscopy (NIRS) for indirect measurement of human saliva secretion in response to taste stimuli for potential application to organoleptic testing. We use an NIRS system to measure extracranial hemodynamics (Hb-signals around the temples) of healthy participants when taste stimuli are taken in their mouths. First, the Hb-signals and volume of expelled saliva (stimulated by distilled-water or sucrose-solution intake) are simultaneously measured and large Hb-signal changes in response to the taste stimuli (Hb-responses) are found. Statistical analysis show that both the Hb response and saliva volume are larger for the sucrose solution than for the distilled water with a significant correlation between them (r = 0.81). The effects of swallowing on the Hb-signals are investigated. Similar Hb responses, differing from the sucrose solution and distilled water, are obtained even though the participants swallow the mouth contents. Finally, functional magnetic resonance imaging is used to identify possible sources of the Hb signals corresponding to salivation. Statistical analysis indicates similar responses in the extracranial regions, mainly around the middle meningeal artery. In conclusion, the identified correlation between extracranial hemodynamics and the saliva volume suggests that NIRS is applicable to the measurement of hemodynamic signals accompanying stimulated saliva secretion. PMID:21529092

  14. [Near-infrared reflectance spectroscopy analytic model established for the IVDMD of Cichorium intybus L].

    PubMed

    Hu, Chao; Bai, Shi-qie; Zhang, Yu; Yan, Jia-jun; You, Ming-hong; Li, Da-xu; Bai, Ling; Zhang Jin

    2014-08-01

    Chicory (Cichorium intybus L.) is a new type of forage grasses of high yield and quality with a great value of popularization and utilization. In vitro dry matter digestibility (IVDMD) is one of the important indicators of the nutritional value of forage evaluation. For the study of establishment of Chicory IVDMD NIRS quantitative analysis model, seventy-two species with different genotypes, different growth stages of 204 chicory samples of aboveground material were collected, and by Fourier transform near-infrared diffuse reflectance spectroscopy, through the use of different regression algorithms, can comparing different spectral ranges and spectral pretreatment methods, eight chicory IVDMD NIRS calibration models were established, and the best calibration model parameters were chosen. Its calibration coefficient of determination (Ri) and external validation coefficient of determination (Rval2) were 0.95317 and 0.90455, calibration standard deviation (RMSEC) and predictive standard deviation (RMSEP) was 1.977 99% and 2.008 82%, and the correlation coefficient (r) between predicted values and chemical values was 0.95108. The results show that using NIRS to determine chicory IVDMD is feasible, and provided a rapid analysis method for the determination IVDMD of chicory. PMID:25474939

  15. [Near-infrared reflectance spectroscopy analytic model established for the IVDMD of Cichorium intybus L].

    PubMed

    Hu, Chao; Bai, Shi-qie; Zhang, Yu; Yan, Jia-jun; You, Ming-hong; Li, Da-xu; Bai, Ling; Zhang Jin

    2014-08-01

    Chicory (Cichorium intybus L.) is a new type of forage grasses of high yield and quality with a great value of popularization and utilization. In vitro dry matter digestibility (IVDMD) is one of the important indicators of the nutritional value of forage evaluation. For the study of establishment of Chicory IVDMD NIRS quantitative analysis model, seventy-two species with different genotypes, different growth stages of 204 chicory samples of aboveground material were collected, and by Fourier transform near-infrared diffuse reflectance spectroscopy, through the use of different regression algorithms, can comparing different spectral ranges and spectral pretreatment methods, eight chicory IVDMD NIRS calibration models were established, and the best calibration model parameters were chosen. Its calibration coefficient of determination (Ri) and external validation coefficient of determination (Rval2) were 0.95317 and 0.90455, calibration standard deviation (RMSEC) and predictive standard deviation (RMSEP) was 1.977 99% and 2.008 82%, and the correlation coefficient (r) between predicted values and chemical values was 0.95108. The results show that using NIRS to determine chicory IVDMD is feasible, and provided a rapid analysis method for the determination IVDMD of chicory. PMID:25508718

  16. Near-infrared integral-field spectroscopy of violent starburst environments

    NASA Astrophysics Data System (ADS)

    de Grijs, Richard

    2006-01-01

    Near-infrared (NIR) integral-field spectroscopy (IFS) of violent starburst environments at high spatial (and spectral) resolution has the potential to revolutionise our ideas regarding the local interactions between the newly formed massive stars and the interstellar medium (ISM) of their host galaxies. To illustrate this point, I present NIR IFS analysis of the central starburst region of NGC 1140, obtained with CIRPASS on Gemini-South. While strong [FeII] emission is found throughout the galaxy, higher-order Brackett emission is predominantly associated with the northern starburst region. Based on the spatial distributions of the [FeII] versus Brackett line emission, I conclude that a galaxy-wide starburst was induced several ×107 yr ago, with more recent starburst activity concentrated around the northern starburst region. I look forward and discuss the exciting prospects that IFS at higher spatial (and spectral) resolution will allow us trace (i) the massive outflows ("superwinds") expected to originate in the dense, young massive star clusters commonly found in intense starburst environments, and (ii) their impact on the galaxy's ISM.

  17. Continuous correction of differential path length factor in near-infrared spectroscopy

    PubMed Central

    Moore, Jason H.; Diamond, Solomon G.

    2013-01-01

    Abstract. In continuous-wave near-infrared spectroscopy (CW-NIRS), changes in the concentration of oxyhemoglobin and deoxyhemoglobin can be calculated by solving a set of linear equations from the modified Beer-Lambert Law. Cross-talk error in the calculated hemodynamics can arise from inaccurate knowledge of the wavelength-dependent differential path length factor (DPF). We apply the extended Kalman filter (EKF) with a dynamical systems model to calculate relative concentration changes in oxy- and deoxyhemoglobin while simultaneously estimating relative changes in DPF. Results from simulated and experimental CW-NIRS data are compared with results from a weighted least squares (WLSQ) method. The EKF method was found to effectively correct for artificially introduced errors in DPF and to reduce the cross-talk error in simulation. With experimental CW-NIRS data, the hemodynamic estimates from EKF differ significantly from the WLSQ (p<0.001). The cross-correlations among residuals at different wavelengths were found to be significantly reduced by the EKF method compared to WLSQ in three physiologically relevant spectral bands 0.04 to 0.15 Hz, 0.15 to 0.4 Hz and 0.4 to 2.0 Hz (p<0.001). This observed reduction in residual cross-correlation is consistent with reduced cross-talk error in the hemodynamic estimates from the proposed EKF method. PMID:23640027

  18. Measurement of oxidative metabolism of the working human muscles by near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Yücetaş, Akin; Şayli, Ömer; Karahan, Mustafa; Akin, Ata

    2006-02-01

    Monitoring the oxygenation of skeletal muscle tissues during rest to work transient provides valuable information about the performance of a particular tissue in adapting to aerobic glycolysis. In this paper we analyze the temporal relation of O II consumption with deoxy-hemoglobin (Hb) signals measured by functional Near Infrared Spectroscopy (fNIRS) technique during moderate isotonic forearm finger joint flexion exercise under ischemic conditions and model it with a mono exponential equation with delay. The time constants of fitting equation are questioned under two different work loads and among subjects differing in gender. Ten (6 men and 4 women) subjects performed isotonic forearm finger joint flexion exercise with two different loads. It is shown that under the same load, men and women subjects generate similar time constants and time delays. However, apparent change in time constants and time delays were observed when exercise was performed under different loads. When t-test is applied to compare the outputs for time constants between 0.41202 Watts and 0.90252 Watts, P value of 9.3445x10 -4 < 0.05 is observed which implies that the differences between the time constants are statistically significant. When the same procedure is applied for the time delay comparison, P value of 0.027<0.05 is observed which implies that also the differences between the time delays are statistically significant.

  19. Effect of valsalva maneuver-induced hemodynamic changes on brain near-infrared spectroscopy measurements.

    PubMed

    Tsubaki, Atsuhiro; Kojima, Sho; Furusawa, Adriane Akemi; Onishi, Hideaki

    2013-01-01

    Near-infrared spectroscopy (NIRS) is widely used to measure human brain activation on the basis of cerebral hemodynamic response. However, a limitation of NIRS is that systemic changes influence the measured signals. The purpose of this study was to clarify the relationship between NIRS signals and blood pressure during the Valsalva maneuver. Nine healthy volunteers performed a 20-s Valsalva maneuver to change their blood pressure. Changes in oxyhemoglobin (O2Hb) concentration were measured with 34 channels with an inter-optode distance of 30 mm for deep-penetration measurements (deepO2Hb) and 9 channels with an inter-optode distance of 15 mm for shallow-penetration measurements (shallowO2Hb). The difference value (diffO2Hb) between deepO2Hb and shallowO2Hb was calculated. Mean arterial pressure (MAP) was recorded by volume clamping the finger pulse, and skin blood flow changes were measured at the forehead. Pearson's correlation coefficients between deepO2Hb and MAP, shallowO2Hb and MAP, and diffO2Hb and MAP were 0.893 (P < 0.01), 0.963 (P < 0.01), and 0.831 (P < 0.01), respectively. The results suggest that regional and systemic changes in the cardiovascular state strongly influence NIRS signals. PMID:23852482

  20. Shed a light in fatigue detection with near-infrared spectroscopy during long-lasting driving

    NASA Astrophysics Data System (ADS)

    Gao, Yuan; Pan, Boan; Li, Kai; Li, Ting

    2016-03-01

    Fatigue driving is one of the leading roles to induce traffic accident and injury, which urgently desires a novel technique to monitor the fatigue level at driving. Functional near infrared spectroscopy (fNIRS) is capable of noninvasive monitoring brain-activities-related hemodynamic responses. Here, we developed a fINRS imager and setup a classic psychological experiment to trigger visual divided attention which varied responding to driving fatigue, and attempted to record the drive-fatigue-level correlated hemodynamic response in the prefrontal cortex. 7 volunteers were recruited to take 7 hours driving and the experimental test was repeated every 1 hour and 8 times in total. The hemodynamic response were extracted and graphed with pseudo image. The analysis on the relationship between the fNIRS-measured hemodynamic response and fatigue level finally displayed that the oxyhemoglobin concentration in one channel of left prefrontal lobe increased with driving duration in significant correlation. And the spatial pattern of hemodynamic response in the prefrontal lobe varied with driving duration as well. The findings indicated the potential of fNIRSmeasured hemodynamic index in some sensitive spot of prefrontal lobe as a driving fatigue indicator and the promising use of fNIRS in traffic safety field.

  1. Near-infrared spectroscopy technique to evaluate the effects of drugs in treating traumatic brain edema

    NASA Astrophysics Data System (ADS)

    Xie, J.; Qian, Z.; Yang, T.; Li, W.; Hu, G.

    2011-01-01

    The aim of this study was to evaluate the effects of several drugs in treating traumatic brain edema (TBE) following traumatic brain injury (TBI) using near-infrared spectroscopy (NIRs) technology. Rats with TBE models were given hypertonic saline (HS), mannitol and mannitol+HS respectively for different groups. Light scattering properties of rat's local cortex was measured by NIRs within the wavelength range from 700 to 850 nm. TBE models were built in rats' left brains. The scattering properties of the right and left target corresponding to the position of normal and TBE tissue were measured and recorded in vivo and real-time by a bifurcated needle probe. The brain water contents (BWC) were measured by the wet and dry weight method after injury and treatment hours 1, 6, 24, 72 and 120. A marked linear relationship was observed between reduced scattering coefficient (μs') and BWC. By recording μs' of rats' brains, the entire progressions of effects of several drugs were observed. The result may suggest that the NIRs techniques have a potential for assessing effects in vivo and real-time on treatment of the brain injury.

  2. Functional connectivity in the prefrontal cortex measured by near-infrared spectroscopy during ultrarapid object recognition

    NASA Astrophysics Data System (ADS)

    Medvedev, Andrei V.; Kainerstorfer, Jana M.; Borisov, Sergey V.; Vanmeter, John

    2011-01-01

    Near-infrared spectroscopy (NIRS) is a developing technology for low-cost noninvasive functional brain imaging. With multichannel optical instruments, it becomes possible to measure not only local changes in hemoglobin concentrations but also temporal correlations of those changes in different brain regions which gives an optical analog of functional connectivity traditionally measured by fMRI. We recorded hemodynamic activity during the Go-NoGo task from 11 right-handed subjects with probes placed bilaterally over prefrontal areas. Subjects were detecting animals as targets in natural scenes pressing a mouse button. Data were low-pass filtered <1 Hz and cardiac/respiration/superficial layers artifacts were removed using Independent Component Analysis. Fisher's transformed correlations of poststimulus responses (30 s) were averaged over groups of channels unilaterally in each hemisphere (intrahemispheric connectivity) and the corresponding channels between hemispheres (interhemispheric connectivity). The hemodynamic response showed task-related activation (an increase/decrease in oxygenated/deoxygenated hemoglobin, respectively) greater in the right versus left hemisphere. Intra- and interhemispheric functional connectivity was also significantly stronger during the task compared to baseline. Functional connectivity between the inferior and the middle frontal regions was significantly stronger in the right hemisphere. Our results demonstrate that optical methods can be used to detect transient changes in functional connectivity during rapid cognitive processes.

  3. Regional Changes in Cerebral Oxygenation During Repeated Passive Movement Measured by Functional Near-infrared Spectroscopy

    PubMed Central

    Sugawara, Kazuhiro; Onishi, Hideaki; Tsubaki, Atsuhiro; Takai, Haruna; Tokunaga, Yuta; Tamaki, Hiroyuki

    2015-01-01

    The aim of this study is to investigate the influence of passive movement repetition frequency at 1.5-Hz and 1-Hz on changes in cerebral oxygenation and assess the temporal properties of these changes using functional near-infrared spectroscopy (fNIRS). No significant differences in systemic hemodynamics were observed between resting and passive movement phases for either 1.5-Hz or 1-Hz trial. Changes in cortical oxygenation as measured by fNIRS in bilateral supplementary motor cortex (SMC), left primary motor cortex (M1), left primary somatosensory cortex (S1), and left posterior association area (PAA) during passive movement of the right index finger revealed greater cortical activity at only 1.5-Hz movement frequency. However, there were no significant differences in the time for peak oxyhemoglobin (oxyHb) among regions (bilateral SMC, 206.4 ± 14.4 s; left M1, 199.1 ± 14.8 s; left S1, 207.3 ± 9.4 s; left PAA, 219.1 ± 10.2 s). Therefore, our results that passive movement above a specific frequency may be required to elicit a changed in cerebral oxygenation, and the times of peak ΔoxyHb did not differ significantly among measured regions. PMID:26635590

  4. Measurement of oxygen consumption during muscle flaccidity exercise by near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Fukuda, K.; Fukawa, Y.

    2013-03-01

    Quantitative measurement oxygen consumption in the muscles is important to evaluate the effect of the exercise. Near-infrared spectroscopy (NIRS) is a noninvasive method for measuring muscle oxygenation. However, measurement results are affected by blood volume change due to changes in the blood pressure. In order to evaluate changes in blood volume and to improve measurement accuracy, we proposed a calculation method of three-wavelength measurement with considering the scattering factor and the measurement with monitoring blood flow for measuring the temporal change of the oxygen concentration more precisely. We applied three-wavelength light source (680nm, 808nm and 830nm) for the continued wave measurement. Two detectors (targeted detector and the reference detector) were placed near the target muscle and apart from it. We measured the blood flow by controlling the intravascular pressure and the oxygen consumption with the handgrip exercise in the forearm. The measured results show that the scattering factor contains the artifact at the surface and the blood flow in the artery and the vein in the same phase. The artifact and the blood flow in the same phase are reduced from the oxygenated and the deoxygenated hemoglobin densities. Thus our proposed method is effective for reducing the influence of the artifact and the blood flow in the same phase from the oxygen consumption measurement. Further, it is shown that the oxygen consumption is measured more accurately by subtracting the blood flow measured by the reference detector.

  5. Brain-computer interface using a simplified functional near-infrared spectroscopy system.

    PubMed

    Coyle, Shirley M; Ward, Tomás E; Markham, Charles M

    2007-09-01

    A brain-computer interface (BCI) is a device that allows a user to communicate with external devices through thought processes alone. A novel signal acquisition tool for BCIs is near-infrared spectroscopy (NIRS), an optical technique to measure localized cortical brain activity. The benefits of using this non-invasive modality are safety, portability and accessibility. A number of commercial multi-channel NIRS system are available; however we have developed a straightforward custom-built system to investigate the functionality of a fNIRS-BCI system. This work describes the construction of the device, the principles of operation and the implementation of a fNIRS-BCI application, 'Mindswitch' that harnesses motor imagery for control. Analysis is performed online and feedback of performance is presented to the user. Mindswitch presents a basic 'on/off' switching option to the user, where selection of either state takes 1 min. Initial results show that fNIRS can support simple BCI functionality and shows much potential. Although performance may be currently inferior to many EEG systems, there is much scope for development particularly with more sophisticated signal processing and classification techniques. We hope that by presenting fNIRS as an accessible and affordable option, a new avenue of exploration will open within the BCI research community and stimulate further research in fNIRS-BCIs. PMID:17873424

  6. Cerebral autoregulation in the microvasculature measured with near-infrared spectroscopy.

    PubMed

    Kainerstorfer, Jana M; Sassaroli, Angelo; Tgavalekos, Kristen T; Fantini, Sergio

    2015-06-01

    Cerebral autoregulation (CA) is the mechanism that allows the brain to maintain a stable blood flow despite changes in blood pressure. Dynamic CA can be quantified based on continuous measurements of systemic mean arterial pressure (MAP) and global cerebral blood flow. Here, we show that dynamic CA can be quantified also from local measurements that are sensitive to the microvasculature. We used near-infrared spectroscopy (NIRS) to measure temporal changes in oxy- and deoxy-hemoglobin concentrations in the prefrontal cortex of 11 human subjects. A novel hemodynamic model translates those changes into changes of cerebral blood volume and blood flow. The interplay between them is described by transfer function analysis, specifically by a high-pass filter whose cutoff frequency describes the autoregulation efficiency. We have used pneumatic thigh cuffs to induce MAP perturbation by a fast release during rest and during hyperventilation, which is known to enhance autoregulation. Based on our model, we found that the autoregulation cutoff frequency increased during hyperventilation in comparison to normal breathing in 10 out of 11 subjects, indicating a greater autoregulation efficiency. We have shown that autoregulation can reliably be measured noninvasively in the microvasculature, opening up the possibility of localized CA monitoring with NIRS. PMID:25669906

  7. A compact time-resolved system for near infrared spectroscopy based on wavelength space multiplexing

    NASA Astrophysics Data System (ADS)

    Re, Rebecca; Contini, Davide; Caffini, Matteo; Cubeddu, Rinaldo; Spinelli, Lorenzo; Torricelli, Alessandro

    2010-11-01

    We designed and developed a compact dual-wavelength and dual-channel time-resolved system for near-infrared spectroscopy studies of muscle and brain. The system employs pulsed diode lasers as sources, compact photomultipliers, and time-correlated single photon counting boards for detection. To exploit the full temporal and dynamic range of the acquisition technique, we implemented an approach based on wavelength space multiplexing: laser pulses at the two wavelengths are alternatively injected into the two channels by means of an optical 2×2 switch. In each detection line (i.e., in each temporal window), the distribution of photon time-of-flights at one wavelength is acquired. The proposed approach increases the signal-to-noise ratio and avoids wavelength cross-talk with respect to the typical approach based on time multiplexing. The instrument was characterized on tissue phantoms to assess its properties in terms of linearity, stability, noise, and reproducibility. Finally, it was successfully tested in preliminary in vivo measurements on muscle during standard cuff occlusion and on the brain during a motor cortex response due to hand movements.

  8. Classification of change detection and change blindness from near-infrared spectroscopy signals

    NASA Astrophysics Data System (ADS)

    Tanaka, Hirokazu; Katura, Takusige

    2011-08-01

    Using a machine-learning classification algorithm applied to near-infrared spectroscopy (NIRS) signals, we classify a success (change detection) or a failure (change blindness) in detecting visual changes for a change-detection task. Five subjects perform a change-detection task, and their brain activities are continuously monitored. A support-vector-machine algorithm is applied to classify the change-detection and change-blindness trials, and correct classification probability of 70-90% is obtained for four subjects. Two types of temporal shapes in classification probabilities are found: one exhibiting a maximum value after the task is completed (postdictive type), and another exhibiting a maximum value during the task (predictive type). As for the postdictive type, the classification probability begins to increase immediately after the task completion and reaches its maximum in about the time scale of neuronal hemodynamic response, reflecting a subjective report of change detection. As for the predictive type, the classification probability shows an increase at the task initiation and is maximal while subjects are performing the task, predicting the task performance in detecting a change. We conclude that decoding change detection and change blindness from NIRS signal is possible and argue some future applications toward brain-machine interfaces.

  9. Similarity analysis of functional connectivity with functional near-infrared spectroscopy.

    PubMed

    Dalmis, Mehmet Ufuk; Akin, Ata

    2015-08-01

    One of the remaining challenges in functional connectivity (FC) studies is investigation of the temporal variability of FC networks. Recent studies focusing on the dynamic FC mostly use functional magnetic resonance imaging as an imaging tool to investigate the temporal variability of FC. We attempted to quantify this variability via analyzing the functional near-infrared spectroscopy (fNIRS) signals, which were recorded from the prefrontal cortex (PFC) of 12 healthy subjects during a Stroop test. Mutual information was used as a metric to determine functional connectivity between PFC regions. Two-dimensional correlation based similarity measure was used as a method to analyze within-subject and intersubject consistency of FC maps and how they change in time. We found that within-subject consistency (0.61±0.09 ) is higher than intersubject consistency (0.28±0.13 ). Within-subject consistency was not found to be task-specific. Results also revealed that there is a gradual change in FC patterns during a Stroop session for congruent and neutral conditions, where there is no such trend in the presence of an interference effect. In conclusion, we have demonstrated the between-subject, within-subject, and temporal variability of FC and the feasibility of using fNIRS for studying dynamic FC. PMID:26296233

  10. Quantitative analysis of α-mangostin in hydrophilic ointment using near-infrared spectroscopy.

    PubMed

    Peerapattana, Jomjai; Otsuka, Kuniko; Hattori, Yusuke; Otsuka, Makoto

    2015-03-01

    The objective of this research was to quantify the α-mangostin content in mangosteen pericarp (MP) ointment as a colloidal dispersion using near-infrared (NIR) spectroscopy. Various concentrations of MP (IP and EP) ointments containing both internal and external pericarps were prepared and the NIR spectra of these ointments were measured. The NIR spectrum of each ointment was correlated with α-mangostin concentration by partial least square (PLS) regression. Validation of the models was performed and their predictive ability was also investigated. The equation and R(2) value for the prediction of α-mangostin concentration in IP ointment were y=0.9843x+0.4441 and 0.9730 and those in EP ointment were y=0.9569x+0.1142 and 0.9136, respectively. The biases of the IP and EP ointment models were 0.23 and 0.00, respectively. The results showed that NIR could be a useful tool for the quality control of herbal medicine in hydrophilic ointment without any sample preparation. It could predict α-mangostin content in hydrophilic ointment at very low concentration with sufficient accuracy. PMID:24517571

  11. Mayer waves reduce the accuracy of estimated hemodynamic response functions in functional near-infrared spectroscopy.

    PubMed

    Yücel, Meryem A; Selb, Juliette; Aasted, Christopher M; Lin, Pei-Yi; Borsook, David; Becerra, Lino; Boas, David A

    2016-08-01

    Analysis of cerebral hemodynamics reveals a wide spectrum of oscillations ranging from 0.0095 to 2 Hz. While most of these oscillations can be filtered out during analysis of functional near-infrared spectroscopy (fNIRS) signals when estimating stimulus evoked hemodynamic responses, oscillations around 0.1 Hz are an exception. This is due to the fact that they share a common spectral range with typical stimulus evoked hemodynamic responses from the brain. Here we investigate the effect of hemodynamic oscillations around 0.1 Hz on the estimation of hemodynamic response functions from fNIRS data. Our results show that for an expected response of ~1 µM in oxygenated hemoglobin concentration (HbO), Mayer wave oscillations with an amplitude > ~1 µM at 0.1 Hz reduce the accuracy of the estimated response as quantified by a 3 fold increase in the mean squared error and decrease in correlation (R(2) below 0.78) when compared to the true HRF. These results indicate that the amplitude of oscillations at 0.1 Hz can serve as an objective metric of the expected HRF estimation accuracy. In addition, we investigated the effect of short separation regression on the recovered HRF, and found that this improves the recovered HRF when large amplitude 0.1 Hz oscillations are present in fNIRS data. We suspect that the development of other filtering strategies may provide even further improvement. PMID:27570699

  12. Slow spontaneous hemodynamic oscillations during sleep measured with near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Virtanen, Jaakko; Näsi, Tiina; Noponen, Tommi; Toppila, Jussi; Salmi, Tapani; Ilmoniemi, Risto J.

    2011-07-01

    Spontaneous cerebral hemodynamic oscillations below 100 mHz reflect the level of cerebral activity, modulate hemodynamic responses to tasks and stimuli, and may aid in detecting various pathologies of the brain. Near-infrared spectroscopy (NIRS) is ideally suited for both measuring spontaneous hemodynamic oscillations and monitoring sleep, but little research has been performed to combine these two applications. We analyzed 30 all-night NIRS-electroencephalography (EEG) sleep recordings to investigate spontaneous hemodynamic activity relative to sleep stages determined by polysomnography. Signal power of hemodynamic oscillations in the low-frequency (LF, 40-150 mHz) and very-low-frequency (VLF, 3-40 mHz) bands decreased in slow-wave sleep (SWS) compared to light sleep (LS) and rapid-eye-movement (REM) sleep. No statistically significant (p < 0.05) differences in oscillation power between LS and REM were observed. However, the period of VLF oscillations around 8 mHz increased in REM sleep in line with earlier studies with other modalities. These results increase our knowledge of the physiology of sleep, complement EEG data, and demonstrate the applicability of NIRS to studying spontaneous hemodynamic fluctuations during sleep.

  13. Characterizing and authenticating Montilla-Moriles PDO vinegars using near infrared reflectance spectroscopy (NIRS) technology.

    PubMed

    De la Haba, María-José; Arias, Mar; Ramírez, Pilar; López, María-Isabel; Sánchez, María-Teresa

    2014-01-01

    This study assessed the potential of near infrared (NIR) spectroscopy as a non-destructive method for characterizing Protected Designation of Origin (PDO) "Vinagres de Montilla-Moriles" wine vinegars and for classifying them as a function of the manufacturing process used. Three spectrophotometers were evaluated for this purpose: two monochromator instruments (Foss NIRSystems 6500 SY-I and Foss NIRSystems 6500 SY-II; spectral range 400-2,500 nm in both cases) and a diode-array instrument (Corona 45 VIS/NIR; spectral range 380-1,700 nm). A total of 70 samples were used to predict major chemical quality parameters (total acidity, fixed acidity, volatile acidity, pH, dry extract, ash, acetoin, methanol, total polyphenols, color (tonality and intensity), and alcohol content), and to construct models for the classification of vinegars as a function of the manufacturing method used. The results obtained indicate that this non-invasive technology can be used successfully by the vinegar industry and by PDO regulators for the routine analysis of vinegars in order to authenticate them and to detect potential fraud. Slightly better results were achieved with the two monochromator instruments. The findings also highlight the potential of these NIR instruments for predicting the manufacturing process used, this being of particular value for the industrial authentication of traditional wine vinegars. PMID:24561402

  14. Brain activity during the flow experience: a functional near-infrared spectroscopy study.

    PubMed

    Yoshida, Kazuki; Sawamura, Daisuke; Inagaki, Yuji; Ogawa, Keita; Ikoma, Katsunori; Sakai, Shinya

    2014-06-24

    Flow is the holistic experience felt when an individual acts with total involvement. Although flow is likely associated with many functions of the prefrontal cortex (PFC), such as attention, emotion, and reward processing, no study has directly investigated the activity of the PFC during flow. The objective of this study was to examine activity in the PFC during the flow state using functional near-infrared spectroscopy (fNIRS). Twenty right-handed university students performed a video game task under conditions designed to induce psychological states of flow and boredom. During each task and when completing the flow state scale for occupational tasks, change in oxygenated hemoglobin (oxy-Hb) concentration in frontal brain regions was measured using fNIRS. During the flow condition, oxy-Hb concentration was significantly increased in the right and left ventrolateral prefrontal cortex. Oxy-Hb concentration tended to decrease in the boredom condition. There was a significant increase in oxy-Hb concentration in the right and left dorsolateral prefrontal cortex, right and left frontal pole areas, and left ventrolateral PFC when participants were completing the flow state scale after performing the task in the flow condition. In conclusion, flow is associated with activity of the PFC, and may therefore be associated with functions such as cognition, emotion, maintenance of internal goals, and reward processing. PMID:24836375

  15. Dynamic topographic mapping of the human bladder during voiding using functional near-infrared spectroscopy.

    PubMed

    Macnab, Andrew; Stothers, Lynn; Shadgan, Babak

    2009-01-01

    Functional near-infrared spectroscopy (fNIRS) with multichannel instruments and grids of source-detector pairs can map regional change in oxygenation/hemodynamics. Developed for cortical brain mapping, fNIRS technology has relevance in other organs where pathology affects the microcirculation. We describe fNIRS of the human bladder for evaluation of hemodynamic change during voiding. A 5x5-cm grid with two source-detector pairs is placed on the abdomen suprapubically in an asymptomatic male. In four separate trials, after natural bladder filling NIRS-derived changes in oxyhemoglobin (O(2)Hb), deoxyhemoglobin (HHb), and total hemoglobin (tHb) concentration are recorded during voiding (measured via uroflow), using four channels of a four wavelength continuous wave instrument. Graphic and video images (topographic mapping software) are generated. Changes in tHb occur following permission to void that predominantly reflected variation in O(2)Hb; tHb peaks at maximum urine flow then falls to a nadir lasting to uroflow end. Change in fNIRS video color intensity correlates with graphic change in chromophore concentration. Color variations across the mapped area suggest regional hemodynamic variation. fNIRS bladder studies generate reproducible chromophore data consistent with single channel studies, but the dynamic color video and larger tissue area monitored potentially offer new methodology for investigating regional variations in bladder oxygenation and hemodynamics. PMID:19405712

  16. Dynamic topographic mapping of the human bladder during voiding using functional near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Macnab, Andrew; Stothers, Lynn; Shadgan, Babak

    2009-03-01

    Functional near-infrared spectroscopy (fNIRS) with multichannel instruments and grids of source-detector pairs can map regional change in oxygenation/hemodynamics. Developed for cortical brain mapping, fNIRS technology has relevance in other organs where pathology affects the microcirculation. We describe fNIRS of the human bladder for evaluation of hemodynamic change during voiding. A 5×5-cm grid with two source-detector pairs is placed on the abdomen suprapubically in an asymptomatic male. In four separate trials, after natural bladder filling NIRS-derived changes in oxyhemoglobin (O2Hb), deoxyhemoglobin (HHb), and total hemoglobin (tHb) concentration are recorded during voiding (measured via uroflow), using four channels of a four wavelength continuous wave instrument. Graphic and video images (topographic mapping software) are generated. Changes in tHb occur following permission to void that predominantly reflected variation in O2Hb; tHb peaks at maximum urine flow then falls to a nadir lasting to uroflow end. Change in fNIRS video color intensity correlates with graphic change in chromophore concentration. Color variations across the mapped area suggest regional hemodynamic variation. fNIRS bladder studies generate reproducible chromophore data consistent with single channel studies, but the dynamic color video and larger tissue area monitored potentially offer new methodology for investigating regional variations in bladder oxygenation and hemodynamics.

  17. Somatic stimulation causes frontoparietal cortical changes in neonates: a functional near-infrared spectroscopy study.

    PubMed

    Kashou, Nasser H; Dar, Irfaan A; Hasenstab, Kathryn A; Nahhas, Ramzi W; Jadcherla, Sudarshan R

    2017-01-01

    Palmar and plantar grasp are the foremost primitive neonatal reflexes and functions. Persistence of these reflexes in infancy is a sign of evolving cerebral palsy. Our aims were to establish measurement feasibility in a clinical setting and to characterize changes in oxyhemoglobin (HbO) and deoxyhemoglobin (HbD) concentration in the bilateral frontoparietal cortex in unsedated neonates at the crib-side using functional near-infrared spectroscopy (fNIRS). We hypothesized that bilateral concentration changes will occur upon somatic central and peripheral somatic stimulation. Thirteen preterm neonates (five males) underwent time 1, and six (two males) returned for time 2 (mean [Formula: see text] and 47.0 weeks, respectively). Signals from a total of 162 somatic stimuli responses were measured. Response amplitude, duration, and latency were log-transformed and compared between palmar, plantar, and oromotor stimuli using linear mixed models, adjusted for cap, electroencephalogram abnormality, time (1 versus 2), and Sarnat score, if necessary. The oromotor stimulus resulted in a 50% greater response than the palmar or plantar stimuli for HbO left and right hemisphere duration ([Formula: see text]). There were no other statistically significant differences between stimuli for any other outcome ([Formula: see text]). Utilizing fNIRS in conjunction with occupational and physical therapy maneuvers is efficacious to study modifiable and restorative neurophysiological mechanisms. PMID:27570791

  18. Near-infrared spectroscopy measurement of blood oxygenation content and its application in sports practice

    NASA Astrophysics Data System (ADS)

    Xu, Guodong; Gong, Hui; Ge, Xinfa; Luo, Qingming

    2003-12-01

    To research the change characteristics of blood oxygenation content in skeletal muscle, the change regularity between blood oxygenation content and exercise intensity as well as HbO2 and blood lactate acid while taking incremental exercises, we took an in vivo, real-time and continuous measurement on the blood oxygenation content of eight sportsmen when they did incremental exercises of five degrees on a power bicycle using a portable tissue oximeter which is based on the principle of near-infrared spectroscopy(NIRS), simultaneously, we detected the blood lactate acid of subjects after each degree of incremental physical load instantly using a blood lactate analysis equipment. The results showed that the content of HbO2 descended regularly while that of Hb ascended; blood volume decreased; and the density of lactate increased as the intensity of exercises was heightened. The statistics analyses showed that the relationship between HbO2 and blood lactate is rather close (correlation coefficient r=-0.918). With this discovery, a theoretical basis in measuring the relative change of blood oxygenation content non-invasively was evidenced, and a novel technology for assessing the physical situation of sportsman, grasping sports density and evaluating the training effect could be imported.

  19. Predicting the biochemical methane potential of wide range of organic substrates by near infrared spectroscopy.

    PubMed

    Doublet, J; Boulanger, A; Ponthieux, A; Laroche, C; Poitrenaud, M; Cacho Rivero, J A

    2013-01-01

    The use of near infrared spectroscopy (NIRS) as an alternative method to predict the biochemical methane potential (BMP) of a broad range of organic substrates was investigated. A total of 296 samples including most of the substrates treated by anaerobic co-digestion were used for NIRS calibration and validation. The NIRS predictions of the BMP values were satisfactory (Root Mean Square Error = 40 ml CH(4) g(-1) VS(fed); r(2) = 0.85). The integration of the entire substrate diversity in the model remained nevertheless difficult due to the specific organic matter properties of stabilised substrates and the high level of uncertainty of the BMP values. The elaboration of a model restricted to "fresh" substrates allows the practical use of the NIR technique to design and operate anaerobic co-digestion plants. The addition of more samples in the dataset in order to perform local calibrations would probably make the elaboration of a global NIR-model possible. PMID:23196247

  20. Studying social cognition using near-infrared spectroscopy: the case of social Simon effect

    NASA Astrophysics Data System (ADS)

    Costantini, Marcello; Di Vacri, Assunta; Maria Chiarelli, Antonio; Ferri, Francesca; Luca Romani, Gian; Merla, Arcangelo

    2013-02-01

    In order to understand the so-called "social brain," we need to monitor social interactions in face-to-face paradigms. Near-infrared spectroscopy (NIRS) is a promising technique to achieve this goal. We investigate the neuronal underpinnings of sharing a task in a proper social context. We record cortical activity by means of NIRS, while participants perform a joint Simon task. Different from other hemodynamic techniques, NIRS allows us to have both participants sit comfortably close to each other in a realistic and ecological environment. We found higher activation in the sensorimotor cortex while processing compatible trials as compared to incompatible ones referring to one's own action alternative. Strikingly, when the participant was not responding because it was the turn of the other member of the pair, the inferior parietal was activated. This study provides twofold findings: first, they suggest that the joint Simon effect relies more on shared attentional mechanisms than a proper mapping of the other's motor response. Second, they highlight the invaluable contribution NIRS can afford to social neuroscience in order to preserve ecological and naturalistic settings.

  1. Stimulus and optode placement effects on functional near-infrared spectroscopy of visual cortex.

    PubMed

    Kashou, Nasser H; Giacherio, Brenna M

    2016-04-01

    Functional near-infrared spectroscopy has yet to be implemented as a stand-alone technique within an ophthalmology clinical setting, despite its promising advantages. The present study aims to further investigate reliability of visual cortical signals. This was achieved by: (1) assessing the effects of optode placements using the 10-20 International System of Electrode Placement consisting of 28 channels, (2) determining effects of stimulus size on response, and (3) evaluating response variability as a result of cap placement across three sessions. Ten participants with mean age [Formula: see text] years (five male) and varying types of hair color and thickness were recruited. Visual stimuli of black-and-white checkerboards, reversing at a frequency of 7.5 Hz were presented. Visual angles of individual checker squares included 1 deg, 2 deg, 5 deg, 9 deg, and 18 deg. The number of channels that showed response was analyzed for each participant, stimulus size, and session. 1-deg stimulus showed the greatest activation. One of three data collection sessions for each participant gave different results ([Formula: see text]). Hair color and thickness each had an effect upon the overall HbO ([Formula: see text]), while only color had a significant effect for HbD ([Formula: see text]). A reliable level of robustness and consistency is still required for clinical implementation and assessment of visual dysfunction. PMID:27335887

  2. Specificity of hemodynamic brain responses to painful stimuli: a functional near-infrared spectroscopy study.

    PubMed

    Yücel, Meryem A; Aasted, Christopher M; Petkov, Mihayl P; Borsook, David; Boas, David A; Becerra, Lino

    2015-01-01

    Assessing pain in individuals not able to communicate (e.g. infants, under surgery, or following stroke) is difficult due to the lack of non-verbal objective measures of pain. Near-infrared spectroscopy (NIRS) being a portable, non-invasive and inexpensive method of monitoring cerebral hemodynamic activity has the potential to provide such a measure. Here we used functional NIRS to evaluate brain activation to an innocuous and a noxious electrical stimulus on healthy human subjects (n = 11). For both innocuous and noxious stimuli, we observed a signal change in the primary somatosensory cortex contralateral to the stimulus. The painful and non-painful stimuli can be differentiated based on their signal size and profile. We also observed that repetitive noxious stimuli resulted in adaptation of the signal. Furthermore, the signal was distinguishable from a skin sympathetic response to pain that tended to mask it. Our results support the notion that functional NIRS has a potential utility as an objective measure of pain. PMID:25820289

  3. Cerebral near-infrared spectroscopy as a measure of nociceptive evoked activity in critically ill infants.

    PubMed

    Ranger, Manon; Johnston, Celeste C; Limperopoulos, Catherine; Rennick, Janet E; du Plessis, Adre J

    2011-01-01

    Signs of pain may be subtle or absent in a critically ill infant. The complex nature of pain may further obscure its identification and measurement. Because the use of monitoring and neuroimaging techniques has become more common in pain research, an understanding of these specialized technologies is important. Near-infrared spectroscopy (NIRS) is a noninvasive technique for monitoring tissue hemodynamics and oxygenation. There are indications that NIRS is capable of detecting the cerebral hemodynamic changes associated with sensory stimuli, including pain, in infants. These developments suggest that NIRS may play an important role in research focusing on pain perception in critically ill infants. The present review briefly describes the cortical responses to noxious stimuli, which parallel cerebral hemodynamic responses to various stimuli. This is followed by an overview of NIRS technology including a summary of the literature on functional studies that have used NIRS in infants. Current NIRS techniques have well-recognized limitations that must be considered carefully during the measurement and interpretation of the signals. Nonetheless, until more advanced NIRS techniques emerge, the current devices have strengths that should be exploited. PMID:22059205

  4. Liquid 1-propanol studied by neutron scattering, near-infrared, and dielectric spectroscopy

    SciTech Connect

    Sillrén, P.; Matic, A.; Karlsson, M.; Koza, M.; Maccarini, M.; Fouquet, P.; Götz, M.; Bauer, Th.; Gulich, R.; Lunkenheimer, P.; Loidl, A.; Mattsson, J.; Gainaru, C.; Vynokur, E.; Schildmann, S.; Bauer, S.; Böhmer, R.

    2014-03-28

    Liquid monohydroxy alcohols exhibit unusual dynamics related to their hydrogen bonding induced structures. The connection between structure and dynamics is studied for liquid 1-propanol using quasi-elastic neutron scattering, combining time-of-flight and neutron spin-echo techniques, with a focus on the dynamics at length scales corresponding to the main peak and the pre-peak of the structure factor. At the main peak, the structural relaxation times are probed. These correspond well to mechanical relaxation times calculated from literature data. At the pre-peak, corresponding to length scales related to H-bonded structures, the relaxation times are almost an order of magnitude longer. According to previous work [C. Gainaru, R. Meier, S. Schildmann, C. Lederle, W. Hiller, E. Rössler, and R. Böhmer, Phys. Rev. Lett. 105, 258303 (2010)] this time scale difference is connected to the average size of H-bonded clusters. The relation between the relaxation times from neutron scattering and those determined from dielectric spectroscopy is discussed on the basis of broad-band permittivity data of 1-propanol. Moreover, in 1-propanol the dielectric relaxation strength as well as the near-infrared absorbance reveal anomalous behavior below ambient temperature. A corresponding feature could not be found in the polyalcohols propylene glycol and glycerol.

  5. Liquid 1-propanol studied by neutron scattering, near-infrared, and dielectric spectroscopy

    NASA Astrophysics Data System (ADS)

    Sillrén, P.; Matic, A.; Karlsson, M.; Koza, M.; Maccarini, M.; Fouquet, P.; Götz, M.; Bauer, Th.; Gulich, R.; Lunkenheimer, P.; Loidl, A.; Mattsson, J.; Gainaru, C.; Vynokur, E.; Schildmann, S.; Bauer, S.; Böhmer, R.

    2014-03-01

    Liquid monohydroxy alcohols exhibit unusual dynamics related to their hydrogen bonding induced structures. The connection between structure and dynamics is studied for liquid 1-propanol using quasi-elastic neutron scattering, combining time-of-flight and neutron spin-echo techniques, with a focus on the dynamics at length scales corresponding to the main peak and the pre-peak of the structure factor. At the main peak, the structural relaxation times are probed. These correspond well to mechanical relaxation times calculated from literature data. At the pre-peak, corresponding to length scales related to H-bonded structures, the relaxation times are almost an order of magnitude longer. According to previous work [C. Gainaru, R. Meier, S. Schildmann, C. Lederle, W. Hiller, E. Rössler, and R. Böhmer, Phys. Rev. Lett. 105, 258303 (2010)] this time scale difference is connected to the average size of H-bonded clusters. The relation between the relaxation times from neutron scattering and those determined from dielectric spectroscopy is discussed on the basis of broad-band permittivity data of 1-propanol. Moreover, in 1-propanol the dielectric relaxation strength as well as the near-infrared absorbance reveal anomalous behavior below ambient temperature. A corresponding feature could not be found in the polyalcohols propylene glycol and glycerol.

  6. Rapid estimation of nutritional elements on citrus leaves by near infrared reflectance spectroscopy.

    PubMed

    Galvez-Sola, Luis; García-Sánchez, Francisco; Pérez-Pérez, Juan G; Gimeno, Vicente; Navarro, Josefa M; Moral, Raul; Martínez-Nicolás, Juan J; Nieves, Manuel

    2015-01-01

    Sufficient nutrient application is one of the most important factors in producing quality citrus fruits. One of the main guides in planning citrus fertilizer programs is by directly monitoring the plant nutrient content. However, this requires analysis of a large number of leaf samples using expensive and time-consuming chemical techniques. Over the last 5 years, it has been demonstrated that it is possible to quantitatively estimate certain nutritional elements in citrus leaves by using the spectral reflectance values, obtained by using near infrared reflectance spectroscopy (NIRS). This technique is rapid, non-destructive, cost-effective and environmentally friendly. Therefore, the estimation of macro and micronutrients in citrus leaves by this method would be beneficial in identifying the mineral status of the trees. However, to be used effectively NIRS must be evaluated against the standard techniques across different cultivars. In this study, NIRS spectral analysis, and subsequent nutrient estimations for N, K, Ca, Mg, B, Fe, Cu, Mn, and Zn concentration, were performed using 217 leaf samples from different citrus trees species. Partial least square regression and different pre-processing signal treatments were used to generate the best estimation against the current best practice techniques. It was verified a high proficiency in the estimation of N (Rv = 0.99) and Ca (Rv = 0.98) as well as achieving acceptable estimation for K, Mg, Fe, and Zn. However, no successful calibrations were obtained for the estimation of B, Cu, and Mn. PMID:26257767

  7. Cerebral Hemodynamic Responses During Dynamic Posturography: Analysis with a Multichannel Near-Infrared Spectroscopy System

    PubMed Central

    Takakura, Hiromasa; Nishijo, Hisao; Ishikawa, Akihiro; Shojaku, Hideo

    2015-01-01

    To investigate cortical roles in standing balance, cortical hemodynamic activity was recorded from the right hemisphere using near-infrared spectroscopy (NIRS) while subjects underwent the sensory organization test (SOT) protocol that systematically disrupts sensory integration processes (i.e., somatosensory or visual inputs or both). Eleven healthy men underwent the SOT during NIRS recording. Group statistical analyses were performed based on changes in oxygenated hemoglobin concentration in 10 different cortical regions of interest and on a general linear analysis with NIRS statistical parametric mapping. The statistical analyses indicated significant activation in the right frontal operculum (f-Op), right parietal operculum (p-Op), and right superior temporal gyrus (STG), right posterior parietal cortex (PPC), right dorsal and ventral premotor cortex (PMC), and the supplementary motor area (SMA) under various conditions. The activation patterns in response to specific combinations of SOT conditions suggested that (1) f-Op, p-Op, and STG are essential for sensory integration when standing balance is perturbed; (2) the SMA is involved in the execution of volitional action and establishment of new motor programs to maintain postural balance; and (3) the PPC and PMC are involved in the updating and computation of spatial reference frames during instances of sensory conflict between vestibular and visual information. PMID:26635574

  8. Rapid identification of illegal synthetic adulterants in herbal anti-diabetic medicines using near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Feng, Yanchun; Lei, Deqing; Hu, Changqin

    We created a rapid detection procedure for identifying herbal medicines illegally adulterated with synthetic drugs using near infrared spectroscopy. This procedure includes a reverse correlation coefficient method (RCCM) and comparison of characteristic peaks. Moreover, we made improvements to the RCCM based on new strategies for threshold settings. Any tested herbal medicine must meet two criteria to be identified with our procedure as adulterated. First, the correlation coefficient between the tested sample and the reference must be greater than the RCCM threshold. Next, the NIR spectrum of the tested sample must contain the same characteristic peaks as the reference. In this study, four pure synthetic anti-diabetic drugs (i.e., metformin, gliclazide, glibenclamide and glimepiride), 174 batches of laboratory samples and 127 batches of herbal anti-diabetic medicines were used to construct and validate the procedure. The accuracy of this procedure was greater than 80%. Our data suggest that this protocol is a rapid screening tool to identify synthetic drug adulterants in herbal medicines on the market.

  9. Reproducibility of cerebral tissue oxygen saturation measurements by near-infrared spectroscopy in newborn infants

    NASA Astrophysics Data System (ADS)

    Jenny, Carmen; Biallas, Martin; Trajkovic, Ivo; Fauchère, Jean-Claude; Bucher, Hans Ulrich; Wolf, Martin

    2011-09-01

    Early detection of cerebral hypoxemia is an important aim in neonatology. A relevant parameter to assess brain oxygenation may be the cerebral tissue oxygen saturation (StO2) measured by near-infrared spectroscopy (NIRS). So far the reproducibility of StO2 measurements was too low for clinical application, probably due to inhomogeneities. The aim of this study was to test a novel sensor geometry which reduces the influence of inhomogeneities. Thirty clinically stable newborn infants, with a gestational age of median 33.9 (range 26.9 to 41.9) weeks, birth weight of 2220 (820 to 4230) g, postnatal age of 5 (1 to 71) days were studied. At least four StO2 measurements of 1 min duration were carried out using NIRS on the lateral head. The sensor was repositioned between measurements. Reproducibility was calculated by a linear mixed effects model. The mean StO2 was 79.99 +/- 4.47% with a reproducibility of 2.76% and a between-infant variability of 4.20%. Thus, the error of measurement only accounts for 30.1% of the variability. The novel sensor geometry leads to considerably more precise measurements compared to previous studies with, e.g., ~5% reproducibility for the NIRO 300. The novel StO2 values hence have a higher clinical relevance.

  10. Quantitative Determination of Fluorine Content in Blends of Polylactide (PLA)-Talc Using Near Infrared Spectroscopy.

    PubMed

    Tamburini, Elena; Tagliati, Chiara; Bonato, Tiziano; Costa, Stefania; Scapoli, Chiara; Pedrini, Paola

    2016-01-01

    Near-infrared spectroscopy (NIRS) has been widely used for quantitative and/or qualitative determination of a wide range of matrices. The objective of this study was to develop a NIRS method for the quantitative determination of fluorine content in polylactide (PLA)-talc blends. A blending profile was obtained by mixing different amounts of PLA granules and talc powder. The calibration model was built correlating wet chemical data (alkali digestion method) and NIR spectra. Using FT (Fourier Transform)-NIR technique, a Partial Least Squares (PLS) regression model was set-up, in a concentration interval of 0 ppm of pure PLA to 800 ppm of pure talc. Fluorine content prediction (R²cal = 0.9498; standard error of calibration, SEC = 34.77; standard error of cross-validation, SECV = 46.94) was then externally validated by means of a further 15 independent samples (R²EX.V = 0.8955; root mean standard error of prediction, RMSEP = 61.08). A positive relationship between an inorganic component as fluorine and NIR signal has been evidenced, and used to obtain quantitative analytical information from the spectra. PMID:27490548

  11. Characterization of early stage cartilage degradation using diffuse reflectance near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Brown, C. P.; Jayadev, C.; Glyn-Jones, S.; Carr, A. J.; Murray, D. W.; Price, A. J.; Gill, H. S.

    2011-04-01

    Interest in localized and early stage treatment technologies for joint conditions such as osteoarthritis is growing rapidly. It has therefore become important to develop objective measures capable of characterizing the earliest (non-visible) changes associated with degeneration to aid treatment procedures. In addition to assessing tissue before treatment, it is further important to develop an effective, non-destructive means of monitoring post-treatment tissue healing, and of providing the high-quality data needed for trials of developing treatment methods. To investigate its ability to detect the early stages of degeneration in cartilage-on-bone, diffuse reflectance near infrared spectroscopy was applied to normal and osteoarthritic joints. A discriminating function was developed to relate absorbance peaks of interest and track degradation around focal osteoarthritic defects. The function could distinguish between normal and degraded tissue (100% separation of normal tissue from that within 25 mm of a defect) and between different stages of osteoarthritic progression (p < 0.05). This technique allows simple, practical and non-destructive assessment of component-level properties over the full depth of the tissue. It has the potential to increase our understanding of the underlying etiologic and pathogenic processes in early stage degeneration, to assist classification and the development of new treatment methods.

  12. Quantitative Determination of Fusarium proliferatum Concentration in Intact Garlic Cloves Using Near-Infrared Spectroscopy

    PubMed Central

    Tamburini, Elena; Mamolini, Elisabetta; De Bastiani, Morena; Marchetti, Maria Gabriella

    2016-01-01

    Fusarium proliferatum is considered to be a pathogen of many economically important plants, including garlic. The objective of this research was to apply near-infrared spectroscopy (NIRS) to rapidly determine fungal concentration in intact garlic cloves, avoiding the laborious and time-consuming procedures of traditional assays. Preventive detection of infection before seeding is of great interest for farmers, because it could avoid serious losses of yield during harvesting and storage. Spectra were collected on 95 garlic cloves, divided in five classes of infection (from 1-healthy to 5-very highly infected) in the range of fungal concentration 0.34–7231.15 ppb. Calibration and cross validation models were developed with partial least squares regression (PLSR) on pretreated spectra (standard normal variate, SNV, and derivatives), providing good accuracy in prediction, with a coefficient of determination (R2) of 0.829 and 0.774, respectively, a standard error of calibration (SEC) of 615.17 ppb, and a standard error of cross validation (SECV) of 717.41 ppb. The calibration model was then used to predict fungal concentration in unknown samples, peeled and unpeeled. The results showed that NIRS could be used as a reliable tool to directly detect and quantify F. proliferatum infection in peeled intact garlic cloves, but the presence of the external peel strongly affected the prediction reliability. PMID:27428978

  13. Effects of Mandibular Retrusive Deviation on Prefrontal Cortex Activation: A Functional Near-Infrared Spectroscopy Study

    PubMed Central

    Otsuka, Takero; Yamasaki, Ryuichi; Shimazaki, Tateshi; Sasaguri, Kenichi; Kawata, Toshitsugu

    2015-01-01

    The objective of this study was to evaluate occlusal condition by assessing brain activity in the prefrontal cortex, which is associated with emotion. Functional near-infrared spectroscopy (fNIRS) was used to detect changes in cerebral blood flow in the prefrontal cortex of 12 healthy volunteers. The malocclusion model was a custom-made splint that forced the mandible into retrusion. A splint with no modification was used as a control. The cortical activation during clenching was compared between the retrusive position condition and the control condition. A visual analog scale score for discomfort was also obtained during clenching and used to evaluate the interaction between fNIRS data and psychiatric changes. Activation of the prefrontal cortex was significantly greater during clenching in the mandibular retrusive condition than during clenching in the control condition. Furthermore, Spearman rank-correlation coefficient revealed a parallel relation between prefrontal cortex activation and visual analog scale score for discomfort. These results indicate that fNIRS can be used to objectively evaluate the occlusal condition by evaluating activity in the prefrontal cortex. PMID:26075235

  14. Near-infrared spectroscopy for the detection and quantification of bacterial contaminations in pharmaceutical products.

    PubMed

    Quintelas, Cristina; Mesquita, Daniela P; Lopes, João A; Ferreira, Eugénio C; Sousa, Clara

    2015-08-15

    Accurate detection and quantification of microbiological contaminations remains an issue mainly due the lack of rapid and precise analytical techniques. Standard methods are expensive and time-consuming being associated to high economic losses and public health threats. In the context of pharmaceutical industry, the development of fast analytical techniques able to overcome these limitations is crucial and spectroscopic techniques might constitute a reliable alternative. In this work we proved the ability of Fourier transform near infrared spectroscopy (FT-NIRS) to detect and quantify bacteria (Bacillus subtilis, Escherichia coli, Pseudomonas fluorescens, Salmonella enterica, Staphylococcus epidermidis) from 10 to 10(8) CFUs/mL in sterile saline solutions (NaCl 0.9%). Partial least squares discriminant analysis (PLSDA) models showed that FT-NIRS was able to discriminate between sterile and contaminated solutions for all bacteria as well as to identify the contaminant bacteria. Partial least squares (PLS) models allowed bacterial quantification with limits of detection ranging from 5.1 to 9 CFU/mL for E. coli and B. subtilis, respectively. This methodology was successfully validated in three pharmaceutical preparations (contact lens solution, cough syrup and topic anti-inflammatory solution) proving that this technique possess a high potential to be routinely used for the detection and quantification of bacterial contaminations. PMID:26151105

  15. [Determination of Hard Rate of Alfalfa (Medicago sativa L.) Seeds with Near Infrared Spectroscopy].

    PubMed

    Wang, Xin-xun; Chen, Ling-ling; Zhang, Yun-wei; Mao, Pei-sheng

    2016-03-01

    Alfalfa (Medicago sativa L.) is the most commonly grown forage crop due to its better quality characteristics and high adaptability in China. However, there was 20%-80% hard seeds in alfalfa which could not be identified easily from non hard seeds which would cause the loss of seed utilization value and plant production. This experiment was designed for 121 samples of alfalfa. Seeds were collected according to different regions, harvested year and varieties. 31 samples were artificial matched as hard rates ranging from 20% to 80% to establish a model for hard seed rate by near infrared spectroscopy (NIRS) with Partial Least Square (PLS). The objective of this study was to establish a model and to estimate the efficiency of NIRS for determining hard rate of alfalfa seeds. The results showed that the correlation coefficient (R2(cal)) of calibration model was 0.981 6, root mean square error of cross validation (RMSECV) was 5.32, and the ratio of prediction to deviation (RPD) was 3.58. The forecast model in this experiment presented the satisfied precision. The proposed method using NIRS technology is feasible for identification and classification of hard seed in alfalfa. A new method, as nondestructive testing of hard seed rate, was provided to theoretical basis for fast nondestructive detection of hard seed rates in alfalfa. PMID:27400509

  16. Combining near-infrared spectroscopy with electroencephalography and repetitive transcranial magnetic stimulation

    NASA Astrophysics Data System (ADS)

    Näsi, Tiina; Kotilahti, Kalle; Mäki, Hanna; Nissilä, Ilkka; Meriläinen, Pekka

    2009-07-01

    The objective of the study was to assess the usability of a near-infrared spectroscopy (NIRS) device in multimodal measurements. We combined NIRS with electroencephalography (EEG) to record hemodynamic responses and evoked potentials simultaneously, and with transcranial magnetic stimulation (TMS) to investigate hemodynamic responses to repetitive TMS (rTMS). Hemodynamic responses and visual evoked potentials (VEPs) to 3, 6, and 12 s stimuli consisting of pattern-reversing checkerboards were successfully recorded in the NIRS/EEG measurement, and ipsi- and contralateral hemodynamic responses to 0.5, 1, and 2 Hz rTMS in the NIRS/TMS measurement. In the NIRS/EEG measurements, the amplitudes of the hemodynamic responses increased from 3- to 6-s stimulus, but not from 6- to 12-s stimulus, and the VEPs showed peaks N75, P100, and N135. In the NIRS/TMS measurements, the 2-Hz stimulus produced the strongest hemodynamic responses compared to the 0.5- and 1-Hz stimuli. In two subjects oxyhemoglobin concentration decreased and in one increased as a consequence of the 2-Hz rTMS. To locate the origin of the measured NIRS responses, methods have to be developed to investigate TMS-induced scalp muscle contractions. In the future, multimodal measurements may prove useful in monitoring or treating diseases such as stroke or Alzheimer's disease.

  17. Biogas potential from forbs and grass-clover mixture with the application of near infrared spectroscopy.

    PubMed

    Wahid, Radziah; Ward, Alastair James; Møller, Henrik Bjarne; Søegaard, Karen; Eriksen, Jørgen

    2015-12-01

    This study investigated the potentials of forbs; caraway, chicory, red clover and ribwort plantain as substrates for biogas production. One-, two- and four-cut systems were implemented and the influence on dry matter yields, chemical compositions and methane yields were examined. The two- and four-cut systems resulted in higher dry matter yields (kg [total solid, TS] ha(-1)) compared to the one-cut system. The effect of plant compositions on biogas potentials was not evident. Cumulative methane yields (LCH4kg(-1) [volatile solid, VS]) were varied from 279 to 321 (chicory), 279 to 323 (caraway), 273 to 296 (ribwort plantain), 263 to 328 (red clover) and 320 to 352 (grass-clover mixture), respectively. Methane yield was modelled by modified Gompertz equation for comparison of methane production rate. Near infrared spectroscopy showed potential as a tool for biogas and chemical composition prediction. The best prediction models were obtained for methane yield at 29 days (99 samples), cellulose, acid detergent fibre, neutral detergent fibre and crude protein, (R(2)>0.9). PMID:26386414

  18. Studying hemispheric lateralization during a Stroop task through near-infrared spectroscopy-based connectivity

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Sun, Jinyan; Sun, Bailei; Luo, Qingming; Gong, Hui

    2014-05-01

    Near-infrared spectroscopy (NIRS) is a developing and promising functional brain imaging technology. Developing data analysis methods to effectively extract meaningful information from collected data is the major bottleneck in popularizing this technology. In this study, we measured hemodynamic activity of the prefrontal cortex (PFC) during a color-word matching Stroop task using NIRS. Hemispheric lateralization was examined by employing traditional activation and novel NIRS-based connectivity analyses simultaneously. Wavelet transform coherence was used to assess intrahemispheric functional connectivity. Spearman correlation analysis was used to examine the relationship between behavioral performance and activation/functional connectivity, respectively. In agreement with activation analysis, functional connectivity analysis revealed leftward lateralization for the Stroop effect and correlation with behavioral performance. However, functional connectivity was more sensitive than activation for identifying hemispheric lateralization. Granger causality was used to evaluate the effective connectivity between hemispheres. The results showed increased information flow from the left to the right hemispheres for the incongruent versus the neutral task, indicating a leading role of the left PFC. This study demonstrates that the NIRS-based connectivity can reveal the functional architecture of the brain more comprehensively than traditional activation, helping to better utilize the advantages of NIRS.

  19. Monitoring of the cellulosic ethanol fermentation process by near-infrared spectroscopy.

    PubMed

    Pinto, Ariane S S; Pereira, Sandra C; Ribeiro, Marcelo P A; Farinas, Cristiane S

    2016-03-01

    Rapid, efficient, and low-cost technologies for monitoring the fermentation process during second generation (2G) or cellulosic ethanol production are essential for the successful implementation of this process at the commercial scale. Here, the use of near-infrared (NIR) spectroscopy associated with partial least squares (PLS) regression was investigated as a tool for monitoring the production of 2G ethanol from lignocellulosic sugarcane residues including bagasse, straw, and tops. The spectral data was based on a set of 103 alcoholic fermentation samples. Models based on different pre-processing techniques were evaluated. The best root mean square error of prediction (RMSEP) values obtained in the external validation were around 3.02 g/L for ethanol and 6.60 g/L for glucose. The findings showed that the PLS-NIR methodology was efficient in accurately predicting the glucose and ethanol concentrations during the production of 2G ethanol, demonstrating potential for use in monitoring and control of large-scale industrial processes. PMID:26748047

  20. Simultaneous measurement of electroencephalography and near-infrared spectroscopy during voluntary motor preparation

    PubMed Central

    Zama, Takuro; Shimada, Sotaro

    2015-01-01

    We investigated the relationship between electrophysiological activity and haemodynamic response during motor preparation by simultaneous recording of electroencephalography (EEG) and near-infrared spectroscopy (NIRS). It is still unknown how exactly EEG signals correlate with the haemodynamic response, although the activation in the premotor area during motor preparation has been captured by EEG and haemodynamic approaches separately. We conducted EEG-NIRS simultaneous recordings over the sensorimotor area with a self-paced button press task. Participants were instructed to press a button at their own pace after a cue was shown. The result showed that the readiness potential (RP), a negative slow potential shift occurring during motor preparation, on C3 in the extended 10–20 system occurred about 1000 ms before the movement onset. An increase in concentration of oxyhaemoglobin (oxyHb) in the premotor cortex during motor preparation was also confirmed by NIRS, which resulted in a significant correlation between the amplitude of the RP and the change in oxyHb concentration (Pearson’s correlation r2 = 0.235, p = 0.03). We show that EEG-NIRS simultaneous recording can demonstrate the correlation between the RP and haemodynamic response in the premotor cortex contralateral to the performing hand. PMID:26574186

  1. Near-infrared spectroscopy provides continuous monitoring of compromised lower extremity perfusion during cardiac surgery.

    PubMed

    Prkic, Ivana; Stuth, Eckehard A E

    2016-06-01

    Near-infrared spectroscopy (NIRS) is more frequently used to monitor regional oxygenation/perfusion of the cerebral and somatorenal vascular bed during congenital heart surgery. However, NIRS probes can be placed elsewhere to assess regional perfusion. We report the intraoperative use of NIRS probes on both calves of an infant to continuously monitor changes in the regional oxygenation/perfusion of a lower extremity whose perfusion was compromised after femoral arterial line placement. The NIRS trend of the compromised limb was compared with the contralateral limb throughout congenital heart surgery including the period on cardiopulmonary bypass (CPB). Our case report illustrates that NIRS technology can be used to monitor ongoing lower extremity vascular compromise during congenital heart surgery when it is not practical to directly access and continuously assess the limb. Transient vascular compromise after invasive femoral arterial line or sheath placement for cardiac catheterization in small infants is not infrequent. NIRS technology in such circumstances may help to decide whether watchful waiting is acceptable or immediate interventions are indicated. Continuous NIRS monitoring showed that limb regional oxygenation remained depressed during CPB but dramatically increased in the post-CPB period. PMID:27185674

  2. Cortical Signal Analysis and Advances in Functional Near-Infrared Spectroscopy Signal: A Review

    PubMed Central

    Kamran, Muhammad A.; Mannan, Malik M. Naeem; Jeong, Myung Yung

    2016-01-01

    Functional near-infrared spectroscopy (fNIRS) is a non-invasive neuroimaging modality that measures the concentration changes of oxy-hemoglobin (HbO) and de-oxy hemoglobin (HbR) at the same time. It is an emerging cortical imaging modality with a good temporal resolution that is acceptable for brain-computer interface applications. Researchers have developed several methods in last two decades to extract the neuronal activation related waveform from the observed fNIRS time series. But still there is no standard method for analysis of fNIRS data. This article presents a brief review of existing methodologies to model and analyze the activation signal. The purpose of this review article is to give a general overview of variety of existing methodologies to extract useful information from measured fNIRS data including pre-processing steps, effects of differential path length factor (DPF), variations and attributes of hemodynamic response function (HRF), extraction of evoked response, removal of physiological noises, instrumentation, and environmental noises and resting/activation state functional connectivity. Finally, the challenges in the analysis of fNIRS signal are summarized. PMID:27375458

  3. Cortical Signal Analysis and Advances in Functional Near-Infrared Spectroscopy Signal: A Review.

    PubMed

    Kamran, Muhammad A; Mannan, Malik M Naeem; Jeong, Myung Yung

    2016-01-01

    Functional near-infrared spectroscopy (fNIRS) is a non-invasive neuroimaging modality that measures the concentration changes of oxy-hemoglobin (HbO) and de-oxy hemoglobin (HbR) at the same time. It is an emerging cortical imaging modality with a good temporal resolution that is acceptable for brain-computer interface applications. Researchers have developed several methods in last two decades to extract the neuronal activation related waveform from the observed fNIRS time series. But still there is no standard method for analysis of fNIRS data. This article presents a brief review of existing methodologies to model and analyze the activation signal. The purpose of this review article is to give a general overview of variety of existing methodologies to extract useful information from measured fNIRS data including pre-processing steps, effects of differential path length factor (DPF), variations and attributes of hemodynamic response function (HRF), extraction of evoked response, removal of physiological noises, instrumentation, and environmental noises and resting/activation state functional connectivity. Finally, the challenges in the analysis of fNIRS signal are summarized. PMID:27375458

  4. Mayer waves reduce the accuracy of estimated hemodynamic response functions in functional near-infrared spectroscopy

    PubMed Central

    Yücel, Meryem A.; Selb, Juliette; Aasted, Christopher M.; Lin, Pei-Yi; Borsook, David; Becerra, Lino; Boas, David A.

    2016-01-01

    Analysis of cerebral hemodynamics reveals a wide spectrum of oscillations ranging from 0.0095 to 2 Hz. While most of these oscillations can be filtered out during analysis of functional near-infrared spectroscopy (fNIRS) signals when estimating stimulus evoked hemodynamic responses, oscillations around 0.1 Hz are an exception. This is due to the fact that they share a common spectral range with typical stimulus evoked hemodynamic responses from the brain. Here we investigate the effect of hemodynamic oscillations around 0.1 Hz on the estimation of hemodynamic response functions from fNIRS data. Our results show that for an expected response of ~1 µM in oxygenated hemoglobin concentration (HbO), Mayer wave oscillations with an amplitude > ~1 µM at 0.1 Hz reduce the accuracy of the estimated response as quantified by a 3 fold increase in the mean squared error and decrease in correlation (R2 below 0.78) when compared to the true HRF. These results indicate that the amplitude of oscillations at 0.1 Hz can serve as an objective metric of the expected HRF estimation accuracy. In addition, we investigated the effect of short separation regression on the recovered HRF, and found that this improves the recovered HRF when large amplitude 0.1 Hz oscillations are present in fNIRS data. We suspect that the development of other filtering strategies may provide even further improvement. PMID:27570699

  5. Active versus passive listening to auditory streaming stimuli: a near-infrared spectroscopy study

    NASA Astrophysics Data System (ADS)

    Remijn, Gerard B.; Kojima, Haruyuki

    2010-05-01

    We use near-infrared spectroscopy (NIRS) to assess listeners' cortical responses to a 10-s series of pure tones separated in frequency. Listeners are instructed to either judge the rhythm of these ``streaming'' stimuli (active-response listening) or to listen to the stimuli passively. Experiment 1 shows that active-response listening causes increases in oxygenated hemoglobin (oxy-Hb) in response to all stimuli, generally over the (pre)motor cortices. The oxy-Hb increases are significantly larger over the right hemisphere than over the left for the final 5 s of the stimulus. Hemodynamic levels do not vary with changes in the frequency separation between the tones and corresponding changes in perceived rhythm (``gallop,'' ``streaming,'' or ``ambiguous''). Experiment 2 shows that hemodynamic levels are strongly influenced by listening mode. For the majority of time windows, active-response listening causes significantly larger oxy-Hb increases than passive listening, significantly over the left hemisphere during the stimulus and over both hemispheres after the stimulus. This difference cannot be attributed to physical motor activity and preparation related to button pressing after stimulus end, because this is required in both listening modes.

  6. Measurement of Brain Activation During an Upright Stepping Reaction Task Using Functional Near-Infrared Spectroscopy

    PubMed Central

    Huppert, Theodore; Schmidt, Benjamin; Beluk, Nancy; Furman, Joseph; Sparto, Patrick

    2016-01-01

    Functional near-infrared spectroscopy (fNIRS) is a non-invasive brain imaging technology that uses light to measure changes in cortical hemoglobin concentrations. FNIRS measurements are recorded through fiber optic cables, which allow the participant to wear the fNIRS sensors while standing upright. Thus, fNIRS technology is well suited to study cortical brain activity during upright balance, stepping, and gait tasks. In this study, fNIRS was used to measure changes in brain activation from the frontal, motor, and premotor brain regions during an upright step task that required subjects to step laterally in response to visual cues that required executive function control. We hypothesized that cognitive processing during complex stepping cues would elicit brain activation of the frontal cortex in areas involved in cognition. Our results show increased prefrontal activation associated with the processing of the stepping cues. Moreover, these results demonstrate the potential to use fNIRS to investigate cognitive processing during cognitively demanding balance and gait studies. Hum Brain Mapp 34:2817–2828, 2013. VC 2012 Wiley Periodicals, Inc. PMID:23161494

  7. Compliant head probe for positioning electroencephalography electrodes and near-infrared spectroscopy optodes.

    PubMed

    Giacometti, Paolo; Diamond, Solomon G

    2013-02-01

    A noninvasive head probe that combines near-infrared spectroscopy (NIRS) and electroencephalography (EEG) for simultaneous measurement of neural dynamics and hemodynamics in the brain is presented. It is composed of a compliant expandable mechanism that accommodates a wide range of head size variation and an elastomeric web that maintains uniform sensor contact pressure on the scalp as the mechanism expands and contracts. The design is intended to help maximize optical and electrical coupling and to maintain stability during head movement. Positioning electrodes at the inion, nasion, central, and preauricular fiducial locations mechanically shapes the probe to place 64 NIRS optodes and 65 EEG electrodes following the 10-5 scalp coordinates. The placement accuracy, precision, and scalp pressure uniformity of the sensors are evaluated. A root-mean-squared (RMS) positional precision of 0.89 ± 0.23 mm, percent arc subdivision RMS accuracy of 0.19 ± 0.15%, and mean normal force on the scalp of 2.28 ± 0.88 N at 5 mm displacement were found. Geometric measurements indicate that the probe will accommodate the full range of adult head sizes. The placement accuracy, precision, and uniformity of sensor contact pressure of the proposed head probe are important determinants of data quality in noninvasive brain monitoring with simultaneous NIRS-EEG. PMID:23377012

  8. Proposal of auxiliary diagnosis index for autism spectrum disorder using near-infrared spectroscopy.

    PubMed

    Yanagisawa, Kazuki; Nakamura, Nozomi; Tsunashima, Hitoshi; Narita, Naoko

    2016-07-01

    Lack of a diagnostic index is a problem that needs to be overcome in the diagnosis of autism spectrum disorder (ASD), because this problem prevents an objective assessment based on biomarkers. This paper describes the development of a diagnostic index for ASD using near-infrared spectroscopy (NIRS). We investigated continuous prefrontal hemodynamic changes depending on reciprocal disposition of working memory and nonworking memory tasks using two-channel NIRS. NIRS signals in the prefrontal cortex were compared between high-functioning ASD subjects ([Formula: see text]) and typically developed (TD) subjects ([Formula: see text]). The brain activities of the TD subjects were related to experimental design. These results were not confirmed in brain activities of ASD subjects, although the task performance rate was almost equivalent. The brain activities of TD subjects and ASD subjects were evaluated using a weighted separability (WS) index obtained from the feature phase of oxy-hemoglobin and its differential value. Calculation of the [Formula: see text]-test (TD subject versus ASD subject) confirmed that WS was significant. This result showed that the proposed index was useful for evaluation of the brain activity of ASD subjects. PMID:27335890

  9. Intraoperative evaluation of revascularization effect on ischemic muscle hemodynamics using near-infrared diffuse optical spectroscopies

    NASA Astrophysics Data System (ADS)

    Yu, Guoqiang; Shang, Yu; Zhao, Youquan; Cheng, Ran; Dong, Lixin; Saha, Sibu P.

    2011-02-01

    Arterial revascularization in patients with peripheral arterial disease (PAD) reestablishes large arterial blood supply to the ischemic muscles in lower extremities via bypass grafts or percutaneous transluminal angioplasty (PTA). Currently no gold standard is available for assessment of revascularization effects in lower extremity muscles. This study tests a novel near-infrared diffuse correlation spectroscopy flow-oximeter for monitoring of blood flow and oxygenation changes in medial gastrocnemius (calf) muscles during arterial revascularization. Twelve limbs with PAD undergoing revascularization were measured using a sterilized fiber-optic probe taped on top of the calf muscle. The optical measurement demonstrated sensitivity to dynamic physiological events, such as arterial clamping/releasing during bypass graft and balloon inflation/deflation during PTA. Significant elevations in calf muscle blood flow were observed after revascularization in patients with bypass graft (+48.1 +/- 17.5%) and patients with PTA (+43.2 +/- 11.0%), whereas acute post-revascularization effects in muscle oxygenation were not evident. The decoupling of flow and oxygenation after revascularization emphasizes the need for simultaneous measurement of both parameters. The acute elevations/improvements in calf muscle blood flow were associated with significant improvements in symptoms and functions. In total, the investigation corroborates potential of the optical methods for objectively assessing the success of arterial revascularization.

  10. Monitoring angiogenesis using a human compatible calibration for broadband near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Yang, Runze; Zhang, Qiong; Wu, Ying; Dunn, Jeff F.

    2013-01-01

    Angiogenesis is a hallmark of many conditions, including cancer, stroke, vascular disease, diabetes, and high-altitude exposure. We have previously shown that one can study angiogenesis in animal models by using total hemoglobin (tHb) as a marker of cerebral blood volume (CBV), measured using broadband near-infrared spectroscopy (bNIRS). However, the method was not suitable for patients as global anoxia was used for the calibration. Here we determine if angiogenesis could be detected using a calibration method that could be applied to patients. CBV, as a marker of angiogenesis, is quantified in a rat cortex before and after hypoxia acclimation. Rats are acclimated at 370-mmHg pressure for three weeks, while rats in the control group are housed under the same conditions, but under normal pressure. CBV increased in each animal in the acclimation group. The mean CBV (%volume/volume) is 3.49%±0.43% (mean±SD) before acclimation for the experimental group, and 4.76%±0.29% after acclimation. The CBV for the control group is 3.28%±0.75%, and 3.09%±0.48% for the two measurements. This demonstrates that angiogenesis can be monitored noninvasively over time using a bNIRS system with a calibration method that is compatible with human use and less stressful for studies using animals.

  11. Neural correlates of spontaneous deception: A functional near-infrared spectroscopy (fNIRS)study.

    PubMed

    Ding, Xiao Pan; Gao, Xiaoqing; Fu, Genyue; Lee, Kang

    2013-03-01

    Deception is commonly seen in everyday social interactions. However, most of the knowledge about the underlying neural mechanism of deception comes from studies where participants were instructed when and how to lie. To study spontaneous deception, we designed a guessing game modeled after Greene and Paxton (2009) "Proceedings of the National Academy of Sciences, 106(30), 12506-12511", in which lying is the only way to achieve the performance level needed to end the game. We recorded neural responses during the game using near-infrared spectroscopy (NIRS). We found that when compared to truth-telling, spontaneous deception, like instructed deception, engenders greater involvement of such prefrontal regions as the left superior frontal gyrus. We also found that the correct-truth trials produced greater neural activities in the left middle frontal gyrus and right superior frontal gyrus than the incorrect-truth trials, suggesting the involvement of the reward system. Furthermore, the present study confirmed the feasibility of using NIRS to study spontaneous deception. PMID:23340482

  12. Cerebral Hemodynamic Responses During Dynamic Posturography: Analysis with a Multichannel Near-Infrared Spectroscopy System.

    PubMed

    Takakura, Hiromasa; Nishijo, Hisao; Ishikawa, Akihiro; Shojaku, Hideo

    2015-01-01

    To investigate cortical roles in standing balance, cortical hemodynamic activity was recorded from the right hemisphere using near-infrared spectroscopy (NIRS) while subjects underwent the sensory organization test (SOT) protocol that systematically disrupts sensory integration processes (i.e., somatosensory or visual inputs or both). Eleven healthy men underwent the SOT during NIRS recording. Group statistical analyses were performed based on changes in oxygenated hemoglobin concentration in 10 different cortical regions of interest and on a general linear analysis with NIRS statistical parametric mapping. The statistical analyses indicated significant activation in the right frontal operculum (f-Op), right parietal operculum (p-Op), and right superior temporal gyrus (STG), right posterior parietal cortex (PPC), right dorsal and ventral premotor cortex (PMC), and the supplementary motor area (SMA) under various conditions. The activation patterns in response to specific combinations of SOT conditions suggested that (1) f-Op, p-Op, and STG are essential for sensory integration when standing balance is perturbed; (2) the SMA is involved in the execution of volitional action and establishment of new motor programs to maintain postural balance; and (3) the PPC and PMC are involved in the updating and computation of spatial reference frames during instances of sensory conflict between vestibular and visual information. PMID:26635574

  13. Specificity of Hemodynamic Brain Responses to Painful Stimuli: A functional near-infrared spectroscopy study

    PubMed Central

    Yücel, Meryem A.; Aasted, Christopher M.; Petkov, Mihayl P.; Borsook, David; Boas, David A.; Becerra, Lino

    2015-01-01

    Assessing pain in individuals not able to communicate (e.g. infants, under surgery, or following stroke) is difficult due to the lack of non-verbal objective measures of pain. Near-infrared spectroscopy (NIRS) being a portable, non-invasive and inexpensive method of monitoring cerebral hemodynamic activity has the potential to provide such a measure. Here we used functional NIRS to evaluate brain activation to an innocuous and a noxious electrical stimulus on healthy human subjects (n = 11). For both innocuous and noxious stimuli, we observed a signal change in the primary somatosensory cortex contralateral to the stimulus. The painful and non-painful stimuli can be differentiated based on their signal size and profile. We also observed that repetitive noxious stimuli resulted in adaptation of the signal. Furthermore, the signal was distinguishable from a skin sympathetic response to pain that tended to mask it. Our results support the notion that functional NIRS has a potential utility as an objective measure of pain. PMID:25820289

  14. Prefrontal Cortex Haemodynamics and Affective Responses during Exercise: A Multi-Channel Near Infrared Spectroscopy Study

    PubMed Central

    Tempest, Gavin D.; Eston, Roger G.; Parfitt, Gaynor

    2014-01-01

    The dose-response effects of the intensity of exercise upon the potential regulation (through top-down processes) of affective (pleasure-displeasure) responses in the prefrontal cortex during an incremental exercise protocol have not been explored. This study examined the functional capacity of the prefrontal cortex (reflected by haemodynamics using near infrared spectroscopy) and affective responses during exercise at different intensities. Participants completed an incremental cycling exercise test to exhaustion. Changes (Δ) in oxygenation (O2Hb), deoxygenation (HHb), blood volume (tHb) and haemoglobin difference (HbDiff) were measured from bilateral dorsal and ventral prefrontal areas. Affective responses were measured every minute during exercise. Data were extracted at intensities standardised to: below ventilatory threshold, at ventilatory threshold, respiratory compensation point and the end of exercise. During exercise at intensities from ventilatory threshold to respiratory compensation point, ΔO2Hb, ΔHbDiff and ΔtHb were greater in mostly ventral than dorsal regions. From the respiratory compensation point to the end of exercise, ΔO2Hb remained stable and ΔHbDiff declined in dorsal regions. As the intensity increased above the ventilatory threshold, inverse associations between affective responses and oxygenation in (a) all regions of the left hemisphere and (b) lateral (dorsal and ventral) regions followed by the midline (ventral) region in the right hemisphere were observed. Differential activation patterns occur within the prefrontal cortex and are associated with affective responses during cycling exercise. PMID:24788166

  15. Determination of the Mineral Composition and Toxic Element Contents of Propolis by Near Infrared Spectroscopy

    PubMed Central

    González-Martín, M. Inmaculada; Escuredo, Olga; Revilla, Isabel; Vivar-Quintana, Ana M.; Coello, M. Carmen; Palacios Riocerezo, Carlos; Wells Moncada, Guillermo

    2015-01-01

    The potential of near infrared spectroscopy (NIR) with remote reflectance fiber-optic probes for determining the mineral composition of propolis was evaluated. This technology allows direct measurements without prior sample treatment. Ninety one samples of propolis were collected in Chile (Bio-Bio region) and Spain (Castilla-León and Galicia regions). The minerals measured were aluminum, calcium, iron, potassium, magnesium, phosphorus, and some potentially toxic trace elements such as zinc, chromium, nickel, copper and lead. The modified partial least squares (MPLS) regression method was used to develop the NIR calibration model. The determination coefficient (R2) and root mean square error of prediction (RMSEP) obtained for aluminum (0.79, 53), calcium (0.83, 94), iron (0.69, 134) potassium (0.95, 117), magnesium (0.70, 99), phosphorus (0.94, 24) zinc (0.87, 10) chromium (0.48, 0.6) nickel (0.52, 0.7) copper (0.64, 0.9) and lead (0.70, 2) in ppm. The results demonstrated that the capacity for prediction can be considered good for wide ranges of potassium, phosphorus and zinc concentrations, and acceptable for aluminum, calcium, magnesium, iron and lead. This indicated that the NIR method is comparable to chemical methods. The method is of interest in the rapid prediction of potentially toxic elements in propolis before consumption. PMID:26540058

  16. Comparison of near-infrared spectroscopy with CT cerebral blood flow measurements in newborn piglets

    NASA Astrophysics Data System (ADS)

    Brown, Derek W.; Picot, Paul A.; Springett, Roger; Delpy, David T.; Lee, Ting-Yim

    2001-05-01

    Severely premature infants are often at high risk of cerebral hemorrhage or ischemic injury due to their inability to properly regulate blood flow to the brain. If blood flow is too high, the infant is at risk of cerebral hemorrhage, while too little blood flow can result in ischemic injury. The purpose of this research is to design and develop a means of non-invasively measuring cerebral blood flow (CBF) with near infrared spectroscopy (NIRS). Such a device would greatly aid the diagnosis and monitoring of afflicted infants. Previous attempts to measure CBF with NIRS have achieved limited success. In this study we acquired high signal-to-noise NIR spectrum from 600 to 980 nm with a cooled CCD spectrometer. This spectrometer enables the differential path length factor (DPF) to be estimated with accuracy using a second derivative technique described by Matcher et al. The validity of our new approach is determined via direct comparison with a previously validated computed tomography (CT) method. Three newborn piglets were studied. CBF measurements were performed at various partial arterial CO2 tensions (PaCO2) using both the NIRS and CT methods. The results of the two methods correlate well with a relationship of CBFCT equals -4.30 + 1.05 CBFNIRS (r2 equals 0.96).

  17. Using near infrared spectroscopy and heart rate variability to detect mental overload.

    PubMed

    Durantin, G; Gagnon, J-F; Tremblay, S; Dehais, F

    2014-02-01

    Mental workload is a key factor influencing the occurrence of human error, especially during piloting and remotely operated vehicle (ROV) operations, where safety depends on the ability of pilots to act appropriately. In particular, excessively high or low mental workload can lead operators to neglect critical information. The objective of the present study is to investigate the potential of functional near infrared spectroscopy (fNIRS) - a non-invasive method of measuring prefrontal cortex activity - in combination with measurements of heart rate variability (HRV), to predict mental workload during a simulated piloting task, with particular regard to task engagement and disengagement. Twelve volunteers performed a computer-based piloting task in which they were asked to follow a dynamic target with their aircraft, a task designed to replicate key cognitive demands associated with real life ROV operating tasks. In order to cover a wide range of mental workload levels, task difficulty was manipulated in terms of processing load and difficulty of control - two critical sources of workload associated with piloting and remotely operating a vehicle. Results show that both fNIRS and HRV are sensitive to different levels of mental workload; notably, lower prefrontal activation as well as a lower LF/HF ratio at the highest level of difficulty, suggest that these measures are suitable for mental overload detection. Moreover, these latter measurements point toward the existence of a quadratic model of mental workload. PMID:24184083

  18. Oxyhemoglobin changes during cognitive rehabilitation after traumatic brain injury using near infrared spectroscopy.

    PubMed

    Hibino, Shin; Mase, Mitsuhito; Shirataki, Tatsuaki; Nagano, Yuri; Fukagawa, Kazutoshi; Abe, Akiko; Nishide, Yukiko; Aizawa, Ayumi; Iida, Akihiko; Ogawa, Tetsuo; Abe, Junko; Hatta, Takeshi; Yamada, Kazuo; Kabasawa, Hidehiro

    2013-01-01

    To investigate cerebral reactions to cognitive rehabilitation tasks, oxyhemoglobin changes were compared in 9 patients with cognitive impairments after traumatic brain injury (TBI) and 47 healthy controls using functional near infrared spectroscopy (fNIRS) during nine cognitive rehabilitation tasks employed at Nagoya City Rehabilitation Center. Forty-seven measurement channels were placed on the frontal to temporal cortices, and organized into seven channel regions. Oxyhemoglobin changes were normalized based on the mean oxyhemoglobin value at the resting state, and integrated throughout a task. Statistical analyses of the differences between the TBI patients and controls were performed with the two-sided Mann-Whitney U test. Oxyhemoglobin changes were high for both controls and TBI patients in the lateral frontal regions. Oxyhemoglobin changes in TBI patients tended to be higher than controls in the medial frontal regions for most training tasks, and significant differences (p < 0.05) were seen for two tasks in the medial frontal regions. Different regions were activated during the tasks in TBI patients compared to controls. fNIRS measurement is useful in the evaluation of changes of neuronal activities during rehabilitation tasks in TBI patients. PMID:23708220

  19. Normative database of judgment of complexity task with functional near infrared spectroscopy--application for TBI.

    PubMed

    Amyot, Franck; Zimmermann, Trelawny; Riley, Jason; Kainerstorfer, Jana M; Chernomordik, Victor; Mooshagian, Eric; Najafizadeh, Laleh; Krueger, Frank; Gandjbakhche, Amir H; Wassermann, Eric M

    2012-04-01

    The ability to assess frontal lobe function in a rapid, objective, and standardized way, without the need for expertise in cognitive test administration might be particularly helpful in mild traumatic brain injury (TBI), where objective measures are needed. Functional near infrared spectroscopy (fNIRS) is a reliable technique to noninvasively measure local hemodynamic changes in brain areas near the head surface. In this paper, we are combining fNIRS and frameless stereotaxy which allowed us to co-register the functional images with previously acquired anatomical MRI volumes. In our experiment, the subjects were asked to perform a task, evaluating the complexity of daily life activities, previously shown with fMRI to activate areas of the anterior frontal cortex. We reconstructed averaged oxyhemoglobin and deoxyhemoglobin data from 20 healthy subjects in a spherical coordinate. The spherical coordinate is a natural representation of surface brain activation projection. Our results show surface activation projected from the medial frontopolar cortex which is consistent with previous fMRI results. With this original technique, we will construct a normative database for a simple cognitive test which can be useful in evaluating cognitive disability such as mild traumatic brain injury. PMID:22306800

  20. Empirical mode decomposition-based motion artifact correction method for functional near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Gu, Yue; Han, Junxia; Liang, Zhenhu; Yan, Jiaqing; Li, Zheng; Li, Xiaoli

    2016-01-01

    Functional near-infrared spectroscopy (fNIRS) is a promising technique for monitoring brain activity. However, it is sensitive to motion artifacts. Many methods have been developed for motion correction, such as spline interpolation, wavelet filtering, and kurtosis-based wavelet filtering. We propose a motion correction method based on empirical mode decomposition (EMD), which is applied to segments of data identified as having motion artifacts. The EMD method is adaptive, data-driven, and well suited for nonstationary data. To test the performance of the proposed EMD method and to compare it with other motion correction methods, we used simulated hemodynamic responses added to real resting-state fNIRS data. The EMD method reduced mean squared error in 79% of channels and increased signal-to-noise ratio in 78% of channels. Moreover, it produced the highest Pearson's correlation coefficient between the recovered signal and the original signal, significantly better than the comparison methods (p<0.01, paired t-test). These results indicate that the proposed EMD method is a first choice method for motion artifact correction in fNIRS.

  1. Brain correlates of verbal fluency in subthreshold psychosis assessed by functional near-infrared spectroscopy.

    PubMed

    Holper, L; Aleksandrowicz, A; Müller, M; Ajdacic-Gross, V; Haker, H; Fallgatter, A J; Hagenmuller, F; Rössler, W; Kawohl, W

    2015-10-01

    The prevalence of subthreshold psychotic symptoms in the general population has gained increasing interest as a possible precursor of psychotic disorders. The goal of the present study was to evaluate whether neurobiological features of subthreshold psychotic symptoms can be detected using verbal fluency tasks and functional near-infrared spectroscopy (fNIRS). A large data set was obtained from the Zurich Program for Sustainable Development of Mental Health Services (ZInEP). Based on the SCL-90-R subscales 'Paranoid Ideation' and 'Psychoticism' a total sample of 188 subjects was assigned to four groups with different levels of subthreshold psychotic symptoms. All subjects completed a phonemic and semantic verbal fluency task while fNIRS was recorded over the prefrontal and temporal cortices. Results revealed larger hemodynamic (oxy-hemoglobin) responses to the phonemic and semantic conditions compared to the control condition over prefrontal and temporal cortices. Subjects with high subthreshold psychotic symptoms exhibited significantly reduced hemodynamic responses in both conditions compared to the control group. Further, connectivity between prefrontal and temporal cortices revealed significantly weaker patterns in subjects with high subthreshold psychotic symptoms compared to the control group, possibly indicating less incisive network connections associated with subthreshold psychotic symptoms. The present findings provide evidence that subthreshold forms of psychotic symptoms are associated with reduced hemodynamic responses and connectivity in prefrontal and temporal cortices during verbal fluency that can be identified using fNIRS. PMID:26277535

  2. Application of near-infrared spectroscopy with fiber optics for detecting interior quality in peaches

    NASA Astrophysics Data System (ADS)

    Liu, Yande; Ying, Yibin; Chen, Zhongming; Fu, Xiaping

    2004-03-01

    Fourier transform near infrared (FT-NIR) spectroscopy was tested as a non-destructive method to assess the sugar content (SC) and the valid acidity of intact peaches. Calibration models were created from spectral and constituent measurements. Data recorded from two sides of individual peach served as the calibration and the validation sets. Partial least squares (PLS) technique used to develop the prediction models by different data preprocessing. The best model for SC had a high correlation efficient (0.956), a low SEP (0.532), a low SEC (0.542), a SDR value of 3.34(>3.00), and also a small difference between SEP and SEC. The best model for valid acidity had a high correlation coefficient (0.948), a relatively low SEP (0.129), a relatively low SEC (0.124) and a SDR value of 2.68 (<3.00), and also a small difference between SEC and SEP. The results of this study suggest that FT-NIR method can be feasible to detect sugar content rapidly. However, the low acid content in the fruit might have caused the relative insensitivity for prediction valid acidity. Further work is required to optimize and implement this technique.

  3. Crop/weed discrimination using near-infrared reflectance spectroscopy (NIRS)

    NASA Astrophysics Data System (ADS)

    Zhang, Yun; He, Yong

    2006-09-01

    The traditional uniform herbicide application often results in an over chemical residues on soil, crop plants and agriculture produce, which have imperiled the environment and food security. Near-infrared reflectance spectroscopy (NIRS) offers a promising means for weed detection and site-specific herbicide application. In laboratory, a total of 90 samples (30 for each species) of the detached leaves of two weeds, i.e., threeseeded mercury (Acalypha australis L.) and fourleafed duckweed (Marsilea quadrfolia L.), and one crop soybean (Glycine max) was investigated for NIRS on 325- 1075 nm using a field spectroradiometer. 20 absorbance samples of each species after pretreatment were exported and the lacked Y variables were assigned independent values for partial least squares (PLS) analysis. During the combined principle component analysis (PCA) on 400-1000 nm, the PC1 and PC2 could together explain over 91% of the total variance and detect the three plant species with 98.3% accuracy. The full-cross validation results of PLS, i.e., standard error of prediction (SEP) 0.247, correlation coefficient (r) 0.954 and root mean square error of prediction (RMSEP) 0.245, indicated an optimum model for weed identification. By predicting the remaining 10 samples of each species in the PLS model, the results with deviation presented a 100% crop/weed detection rate. Thus, it could be concluded that PLS was an available alternative of for qualitative weed discrimination on NTRS.

  4. Neonatal hemodynamic response to visual cortex activity: high-density near-infrared spectroscopy study

    NASA Astrophysics Data System (ADS)

    Liao, Steve M.; Gregg, Nick M.; White, Brian R.; Zeff, Benjamin W.; Bjerkaas, Katelin A.; Inder, Terrie E.; Culver, Joseph P.

    2010-03-01

    The neurodevelopmental outcome of neonatal intensive care unit (NICU) infants is a major clinical concern with many infants displaying neurobehavioral deficits in childhood. Functional neuroimaging may provide early recognition of neural deficits in high-risk infants. Near-infrared spectroscopy (NIRS) has the advantage of providing functional neuroimaging in infants at the bedside. However, limitations in traditional NIRS have included contamination from superficial vascular dynamics in the scalp. Furthermore, controversy exists over the nature of normal vascular, responses in infants. To address these issues, we extend the use of novel high-density NIRS arrays with multiple source-detector distances and a superficial signal regression technique to infants. Evaluations of healthy term-born infants within the first three days of life are performed without sedation using a visual stimulus. We find that the regression technique significantly improves brain activation signal quality. Furthermore, in six out of eight infants, both oxy- and total hemoglobin increases while deoxyhemoglobin decreases, suggesting that, at term, the neurovascular coupling in the visual cortex is similar to that found in healthy adults. These results demonstrate the feasibility of using high-density NIRS arrays in infants to improve signal quality through superficial signal regression, and provide a foundation for further development of high-density NIRS as a clinical tool.

  5. Prefrontal cortex hemodynamics and age: a pilot study using functional near infrared spectroscopy in children

    PubMed Central

    Anderson, Afrouz A.; Smith, Elizabeth; Chernomordik, Victor; Ardeshirpour, Yasaman; Chowdhry, Fatima; Thurm, Audrey; Black, David; Matthews, Dennis; Rennert, Owen; Gandjbakhche, Amir H.

    2014-01-01

    Cerebral hemodynamics reflect cognitive processes and underlying physiological processes, both of which are captured by functional near infrared spectroscopy (fNIRS). Here, we introduce a novel parameter of Oxygenation Variability directly obtained from fNIRS data —the OV Index—and we demonstrate its use in children. fNIRS data were collected from 17 children (ages 4–8 years), while they performed a standard Go/No-Go task. Data were analyzed using two frequency bands—the first attributed to cerebral autoregulation (CA) (<0.1 Hz) and the second to respiration (0.2–0.3 Hz). Results indicate differences in variability of oscillations of oxygen saturation (SO2) between the two different bands. These pilot data reveal a dynamic relationship between chronological age and OV index in CA associated frequency of <0.1 Hz. Specifically, OV index increased with age between 4 and 6 years. In addition, there was much higher variability in frequencies associated with CA than for respiration across subjects. These findings provide preliminary evidence for the utility of the OV index and are the first to describe the relationship between cerebral autoregulation and age in children using fNIRS methodology. PMID:25565935

  6. Quantitative Determination of Fusarium proliferatum Concentration in Intact Garlic Cloves Using Near-Infrared Spectroscopy.

    PubMed

    Tamburini, Elena; Mamolini, Elisabetta; De Bastiani, Morena; Marchetti, Maria Gabriella

    2016-01-01

    Fusarium proliferatum is considered to be a pathogen of many economically important plants, including garlic. The objective of this research was to apply near-infrared spectroscopy (NIRS) to rapidly determine fungal concentration in intact garlic cloves, avoiding the laborious and time-consuming procedures of traditional assays. Preventive detection of infection before seeding is of great interest for farmers, because it could avoid serious losses of yield during harvesting and storage. Spectra were collected on 95 garlic cloves, divided in five classes of infection (from 1-healthy to 5-very highly infected) in the range of fungal concentration 0.34-7231.15 ppb. Calibration and cross validation models were developed with partial least squares regression (PLSR) on pretreated spectra (standard normal variate, SNV, and derivatives), providing good accuracy in prediction, with a coefficient of determination (R²) of 0.829 and 0.774, respectively, a standard error of calibration (SEC) of 615.17 ppb, and a standard error of cross validation (SECV) of 717.41 ppb. The calibration model was then used to predict fungal concentration in unknown samples, peeled and unpeeled. The results showed that NIRS could be used as a reliable tool to directly detect and quantify F. proliferatum infection in peeled intact garlic cloves, but the presence of the external peel strongly affected the prediction reliability. PMID:27428978

  7. Correction of motion artifacts and serial correlations for real-time functional near-infrared spectroscopy.

    PubMed

    Barker, Jeffrey W; Rosso, Andrea L; Sparto, Patrick J; Huppert, Theodore J

    2016-07-01

    Functional near-infrared spectroscopy (fNIRS) is a relatively low-cost, portable, noninvasive neuroimaging technique for measuring task-evoked hemodynamic changes in the brain. Because fNIRS can be applied to a wide range of populations, such as children or infants, and under a variety of study conditions, including those involving physical movement, gait, or balance, fNIRS data are often confounded by motion artifacts. Furthermore, the high sampling rate of fNIRS leads to high temporal autocorrelation due to systemic physiology. These two factors can reduce the sensitivity and specificity of detecting hemodynamic changes. In a previous work, we showed that these factors could be mitigated by autoregressive-based prewhitening followed by the application of an iterative reweighted least squares algorithm offline. This current work extends these same ideas to real-time analysis of brain signals by modifying the linear Kalman filter, resulting in an algorithm for online estimation that is robust to systemic physiology and motion artifacts. We evaluated the performance of the proposed method via simulations of evoked hemodynamics that were added to experimental resting-state data, which provided realistic fNIRS noise. Last, we applied the method post hoc to data from a standing balance task. Overall, the new method showed good agreement with the analogous offline algorithm, in which both methods outperformed ordinary least squares methods. PMID:27226974

  8. Artifact reduction in long-term monitoring of cerebral hemodynamics using near-infrared spectroscopy

    PubMed Central

    Vinette, Sarah A.; Dunn, Jeff F.; Slone, Edward; Federico, Paolo

    2015-01-01

    Abstract. Near-infrared spectroscopy (NIRS) is a noninvasive neuroimaging technique used to assess cerebral hemodynamics. Its portability, ease of use, and relatively low operational cost lend itself well to the long-term monitoring of hemodynamic changes, such as those in epilepsy, where events are unpredictable. Long-term monitoring is associated with challenges including alterations in behaviors and motion that can result in artifacts. Five patients with epilepsy were assessed for interictal hemodynamic changes and alterations in behavior or motion. Based on this work, visual inspection was used to identify NIRS artifacts during a period of interest, specifically prior to seizures, in four patients. A motion artifact reduction algorithm (MARA, also known as the spline interpolation method) was tested on these data. Alterations in the NIRS measurements often occurred simultaneously with changes in motion and behavior. Occasionally, sharp shift artifacts were observed in the data. When artifacts appeared as sustained baseline shifts in the data, MARA reduced the standard deviation of the data and the appearance improved. We discussed motion and artifacts as challenges associated with long-term monitoring of cerebral hemodynamics in patients with epilepsy and our group’s approach to circumvent these challenges and improve the quality of the data collected. PMID:26158008

  9. Determination of persimmon leaf chloride contents using near-infrared spectroscopy (NIRS).

    PubMed

    de Paz, José Miguel; Visconti, Fernando; Chiaravalle, Mara; Quiñones, Ana

    2016-05-01

    Early diagnosis of specific chloride toxicity in persimmon trees requires the reliable and fast determination of the leaf chloride content, which is usually performed by means of a cumbersome, expensive and time-consuming wet analysis. A methodology has been developed in this study as an alternative to determine chloride in persimmon leaves using near-infrared spectroscopy (NIRS) in combination with multivariate calibration techniques. Based on a training dataset of 134 samples, a predictive model was developed from their NIR spectral data. For modelling, the partial least squares regression (PLSR) method was used. The best model was obtained with the first derivative of the apparent absorbance and using just 10 latent components. In the subsequent external validation carried out with 35 external data this model reached r(2) = 0.93, RMSE = 0.16% and RPD = 3.6, with standard error of 0.026% and bias of -0.05%. From these results, the model based on NIR spectral readings can be used for speeding up the laboratory determination of chloride in persimmon leaves with only a modest loss of precision. The intermolecular interaction between chloride ions and the peptide bonds in leaf proteins through hydrogen bonding, i.e. N-H···Cl, explains the ability for chloride determinations on the basis of NIR spectra. PMID:26935930

  10. [Applications of On-Line Near Infrared Spectroscopy Monitoring Technology in Polymer Processing].

    PubMed

    Chen, Ru-huang; Wang, Xiao-lin; Lin, Xiao-kai; Hu, Xin; Jin, Gang

    2015-06-01

    Due to the significant impact of processing on the performance of polymer products, it is crucial to develop in-line monitoring methods on processing. Based on the feedback data from in-line monitoring the processing parameters can be adjusted, which will contribute to the stability of production, thereby ensuring product quality, reducing energy waste and improving production efficiency. Near infrared spectroscopy (NIR), a low-cost, real-time and accurately quantitative analysis technology, has been widely used in many areas but still under study in polymer processing. The applications of in-line NIR monitoring technology in measuring the content of component, melt index, melt density and dispersion of filler of polymer during processing were reviewed. The existing problems about in-line NIR monitoring technology were pointed out, as well as the suggestions for the corresponding problems. The future trends of in-line NIR monitoring technology were discussed. With the development of fiber optic spectrometer, computer science and chemometrics, it is foreseen that the in-line NIR monitoring technology will make considerable progress in the stability of raw data, methods of pretreatment and modeling, the robustness and accuracy of model. Therefore, in-line NIR monitoring technology will be applied to more areas generating the great economic and environmental value. PMID:26601357

  11. Prefrontal cortex haemodynamics and affective responses during exercise: a multi-channel near infrared spectroscopy study.

    PubMed

    Tempest, Gavin D; Eston, Roger G; Parfitt, Gaynor

    2014-01-01

    The dose-response effects of the intensity of exercise upon the potential regulation (through top-down processes) of affective (pleasure-displeasure) responses in the prefrontal cortex during an incremental exercise protocol have not been explored. This study examined the functional capacity of the prefrontal cortex (reflected by haemodynamics using near infrared spectroscopy) and affective responses during exercise at different intensities. Participants completed an incremental cycling exercise test to exhaustion. Changes (Δ) in oxygenation (O2Hb), deoxygenation (HHb), blood volume (tHb) and haemoglobin difference (HbDiff) were measured from bilateral dorsal and ventral prefrontal areas. Affective responses were measured every minute during exercise. Data were extracted at intensities standardised to: below ventilatory threshold, at ventilatory threshold, respiratory compensation point and the end of exercise. During exercise at intensities from ventilatory threshold to respiratory compensation point, ΔO2Hb, ΔHbDiff and ΔtHb were greater in mostly ventral than dorsal regions. From the respiratory compensation point to the end of exercise, ΔO2Hb remained stable and ΔHbDiff declined in dorsal regions. As the intensity increased above the ventilatory threshold, inverse associations between affective responses and oxygenation in (a) all regions of the left hemisphere and (b) lateral (dorsal and ventral) regions followed by the midline (ventral) region in the right hemisphere were observed. Differential activation patterns occur within the prefrontal cortex and are associated with affective responses during cycling exercise. PMID:24788166

  12. Estimating hydrogen cyanide in forage sorghum ( Sorghum bicolor ) by near-infrared spectroscopy.

    PubMed

    Fox, Glen P; O'Donnell, Natalie H; Stewart, Peter N; Gleadow, Roslyn M

    2012-06-20

    Hydrogen cyanide (HCN) is a toxic chemical that can potentially cause mild to severe reactions in animals when grazing forage sorghum. Developing technologies to monitor the level of HCN in the growing crop would benefit graziers, so that they can move cattle into paddocks with acceptable levels of HCN. In this study, we developed near-infrared spectroscopy (NIRS) calibrations to estimate HCN in forage sorghum and hay. The full spectral NIRS range (400-2498 nm) was used as well as specific spectral ranges within the full spectral range, i.e., visible (400-750 nm), shortwave (800-1100 nm) and near-infrared (NIR) (1100-2498 nm). Using the full spectrum approach and partial least-squares (PLS), the calibration produced a coefficient of determination (R(2)) = 0.838 and standard error of cross-validation (SECV) = 0.040%, while the validation set had a R(2) = 0.824 with a low standard error of prediction (SEP = 0.047%). When using a multiple linear regression (MLR) approach, the best model (NIR spectra) produced a R(2) = 0.847 and standard error of calibration (SEC) = 0.050% and a R(2) = 0.829 and SEP = 0.057% for the validation set. The MLR models built from these spectral regions all used nine wavelengths. Two specific wavelengths 2034 and 2458 nm were of interest, with the former associated with C═O carbonyl stretch and the latter associated with C-N-C stretching. The most accurate PLS and MLR models produced a ratio of standard error of prediction to standard deviation of 3.4 and 3.0, respectively, suggesting that the calibrations could be used for screening breeding material. The results indicated that it should be feasible to develop calibrations using PLS or MLR models for a number of users, including breeding programs to screen for genotypes with low HCN, as well as graziers to monitor crop status to help with grazing efficiency. PMID:22594883

  13. Near-infrared spectroscopy of asteroids in the Polana-family region: Where are the Eulalias?

    NASA Astrophysics Data System (ADS)

    Pinilla-Alonso, N.; Campins, H.; Lorenzi, V.; de Leon, J.; Landsman, Z.; Licandro, J.; Ali-Lagoa, V.

    2014-07-01

    The inner asteroid belt is an important source of Near-Earth Objects (NEOs). This region is located between the ν_6 resonance near 2.15 au and the 3:1 mean-motion resonance with Jupiter at 2.5 au. The two current targets of sample-return missions are believed to originate in the inner belt (e.g., Campins et al. 2010, 2013). These are asteroid (101955) Bennu, target of NASA's OSIRIS-Rex and 1999 JU3, target of JAXA's Hayabusa-2. Both of these asteroids are unlikely to be primordial objects because their collisional lifetime is much shorter than the age of solar system (e.g., Bottke et al. 2005); thus, they are believed to be fragments of larger objects. In searching for their parent bodies, we have studied low-albedo asteroids in the inner belt and we have identified at least five distinct populations: four families (Clarissa, Erigone, Polana and Sulamitis) and the background of low-albedo asteroids outside these families. The background and the Polana family are the two largest populations (Campins et al. 2010; Delbo et al. 2011). In order to characterize this source of NEOs, we decided to carry out a spectroscopic study of the Polana family, which we started in 2010. For this study, we define the Polana family as the low-albedo component of the Nysa-Polana complex. Interestingly, a recent publication (Walsh et al. 2013) suggests that there are two families of primitive asteroids with low inclination in this region that can be distinguished using NIR spectroscopy and that would have (142) Polana and (495) Eulalia as their parents bodies. We present results of two different observational campaigns: Pinilla- Alonso et al. (2014) obtained near-infrared (0.8--2.5 μ m) spectra with NICS at the TNG telescope at the ''El Roque de los Muchachos'' observatory (La Palma, Spain) and with SpeX (Rayner et al. 2003) at NASA's IRTF on Mauna Kea, Hawaii. In de Leon et al. (2014), we present visible spectra of smaller members of this population (H>15), using the 10.4-m Gran

  14. Prediction of alpaca fibre quality by near-infrared reflectance spectroscopy.

    PubMed

    Canaza-Cayo, A W; Alomar, D; Quispe, E

    2013-07-01

    Rapid and efficient methods to evaluate variables associated with fibre quality are essential in animal breeding programs and fibre trade. Near-infrared reflectance spectroscopy (NIRS) combined with multivariate analysis was evaluated to predict textile quality attributes of alpaca fibre. Raw samples of fibres taken from male and female Huacaya alpacas (n = 291) of different ages and colours were scanned and their visible-near-infrared (NIR; 400 to 2500 nm) reflectance spectra were collected and analysed. Reference analysis of the samples included mean fibre diameter (MFD), standard deviation of fibre diameter (SDFD), coefficient of variation of fibre diameter (CVFD), mean fibre curvature (MFC), standard deviation of fibre curvature (SDFC), comfort factor (CF), spinning fineness (SF) and staple length (SL). Patterns of spectral variation (loadings) were explored by principal component analysis (PCA), where the first four PC's explained 99.97% and the first PC alone 95.58% of spectral variability. Calibration models were developed by modified partial least squares regression, testing different mathematical treatments (derivative order, subtraction gap, smoothing segment) of the spectra, with or without applying spectral correction algorithms (standard normal variate and detrend). Equations were selected through one-out cross-validation according to the proportion of explained variance (R 2CV), root mean square error in cross-validation (RMSECV) and the residual predictive deviation (RPD), which relates the standard deviation of the reference data to RMSECV. The best calibration models were accomplished when using the NIR region (1100 to 2500 nm) for the prediction of MFD and SF, with R 2CV = 0.90 and 0.87; RMSECV = 1.01 and 1.08 μm and RPD = 3.13 and 2.73, respectively. Models for SDFD, CVFD, MFC, SDFC, CF and SL had lower predictive quality with R 2CV < 0.65 and RPD < 1.5. External validation performed for MFD and SF on 91 samples was slightly poorer than cross

  15. Detection of Organic Matter in Sediments with Near-Infrared Reflectance Spectroscopy: Effects of Mineralogy, Albedo and Hydration

    NASA Astrophysics Data System (ADS)

    Kaplan, H. H.; Milliken, R.

    2014-12-01

    Laboratory, field-, and satellite-based visible-near infrared reflectance spectroscopy allows for rapid, remote, and non-destructive analysis of geologic materials to identify mineralogy as well as organic compounds. This type of analysis has potential to aid the search for organics on Mars as a means of first detection of reduced carbon, or to study organic matter nondestructively in valuable samples such as meteorites. In order to assess potential applications of this method we aim to answer fundamental questions about detection limits and quantification of organic matter using reflectance spectroscopy. Laboratory mixtures and natural samples are measured for total organic carbon (TOC in wt.%) with standard methods and reflectance spectroscopy. Absorption features due to C-H2 and C-H3 bonds are observed in the 3.3 to 3.5μm (3000 to 2850 cm-1) wavelength region. A strong H2O feature near 3μm, as well as carbonate-related absorptions near 3.4µm, are also found in this spectral region and can complicate detection of organic material, particularly at low TOC values. In natural samples without carbonate there appears to be a linear trend between TOC and the band depth of organic absorptions; samples that have low albedo, or strong 3μm water features deviate from this trend line. Spectra of samples with carbonate may be modeled with Gaussians to remove the influence of the carbonate features and better match the organic absorption trend. Early results indicate that quantification of organic matter in natural fine-grained samples using reflectance spectroscopy will need to take low-albedo components and water content into account. Detection limits may also depend on these properties; organic absorption features are clearly seen in the lowest TOC sample measured so far (0.08wt% or 800ppm), which is a relatively bright, carbonate-free, quartz- and clay-dominated outcrop sample. A series of laboratory experiments have been undertaken in which known amounts of organic

  16. Near infrared spectroscopy and chemometrics analysis of complex traits in animal physiology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Near infrared reflectance (NIR) applications have been expanding from the traditional framework of small molecule chemical purity and composition (as defined by spectral libraries) to complex system analysis and holistic exploratory approaches to questions in biochemistry, biophysics and environment...

  17. Near-Infrared spectroscopy of the possible nova candidate PNV J17355050-2934240

    NASA Astrophysics Data System (ADS)

    Srivastava, Mudit; Joshi, Vishal; Banerjee, D. P. K.; Ashok, N. M.

    2016-03-01

    We report near-infrared observations of PNV J17355050-2934240 which has been reported as a possible nova candidate in the CBAT TOCP site (http://www.cbat.eps.harvard.edu/unconf/followups/J17355050-2934240.html).

  18. Ground-based near infrared spectroscopy of Jupiter's ring and moons

    NASA Astrophysics Data System (ADS)

    Wong, Michael H.; de Pater, Imke; Showalter, Mark R.; Roe, Henry G.; Macintosh, Bruce; Verbanac, Giuli

    2006-12-01

    The backscattered reflectivity of Jupiter's ring has been previously measured over distinct visible and near infrared wavelength bands by a number of ground-based and spaceborne instruments. We present spectra of Jupiter's main ring from 2.21-2.46 μm taken with the NIRSPEC spectrometer at the W.M. Keck observatory. At these wavelengths, scattered light from Jupiter is minimal due to the strong absorption of methane in the planet's atmosphere. We find an overall flat spectral slope over this wavelength interval, except for a possible red slope shortward of 2.25 μm. We extended the spectral coverage of the ring to shorter wavelengths by adding a narrow-band image at 1.64 μm, and show results from 2.27-μm images over phase angles of 1.2°-11.0°. Our images at 1.64 and 2.27 μm reveal that the halo contribution is stronger at the shorter wavelength, possibly due to the redder spectrum of the ring parent bodies as compared with the halo dust component. We find no variation in main ring reflectivity over the 1.2°-11.0° phase angle range at 2.27 μm. We use adaptive optics imaging at the longer wavelength L' band (3.4-4.1 μm) to determine a 2- σ upper limit of 22 m of vertically-integrated I/F. Our observing campaign also produced an L' image of Callisto, showing a darker leading hemisphere, and a spectrum of Amalthea over the 2.2-2.5 and 2.85-3.03 μm ranges, showing deep 3-μm absorption.

  19. HIGH-RESOLUTION, DIFFERENTIAL, NEAR-INFRARED TRANSMISSION SPECTROSCOPY OF GJ 1214b

    SciTech Connect

    Crossfield, I. J. M.; Hansen, Brad M. S.; Barman, Travis

    2011-08-01

    The nearby star GJ 1214 hosts a planet intermediate in radius and mass between Earth and Neptune, resulting in some uncertainty as to its nature. We have observed this planet, GJ 1214b, during transit with the high-resolution, near-infrared NIRSPEC spectrograph on the Keck II telescope, in order to characterize the planet's atmosphere. By cross-correlating the spectral changes through transit with a suite of theoretical atmosphere models, we search for variations associated with absorption in the planet atmosphere. Our observations are sufficient to rule out tested model atmospheres with wavelength-dependent transit depth variations {approx}> 5 x 10{sup -4} over the wavelength range 2.1-2.4 {mu}m. Our sensitivity is limited by variable slit loss and telluric transmission effects. We find no positive signatures but successfully rule out a number of plausible atmospheric models, including the default assumption of a gaseous, H-dominated atmosphere in chemical equilibrium. Such an atmosphere can be made consistent if the absorption due to methane is reduced. Clouds can also render such an atmosphere consistent with our observations, but only if they lie higher in the atmosphere than indicated by recent optical and infrared measurements. When taken in concert with other observational constraints, our results support a model in which the atmosphere of GJ 1214b contains significant H and He, but where CH{sub 4} is depleted. If this depletion is the result of photochemical processes, it may also produce a haze that suppresses spectral features in the optical.

  20. Near-infrared spectroscopy (NIRS) analysis of major components of milk and the development of analysis instrument

    NASA Astrophysics Data System (ADS)

    Liu, Jingwei; Ji, Zhongpeng; Tian, Mi

    2014-11-01

    In this study, we introduce a new spectroscopy analysis instrument, along with applied research based on the near-infrared spectroscopy (NIRS) of the major components of milk. Firstly, we analyzed and compared the characteristics of existing near-infrared spectrometers. Then, according to the major component spectra of milk, the spectral range, spectral resolution, and other parameters of the analysis instrument were determined, followed by the construction of a spectroscopy-analysis instrument based on acousto-optic tunable filters (AOTFs). Secondly, on the basis of application requirements, we obtained spectral information from a variety of test samples. Finally, qualitative and quantitative testing of the major components of the milk samples was carried out via typical analysis methods and a mathematical model of NIRS. Thus, this study provides a technical reference for the development of spectroscopy instruments and their applied research.