Dissertations / Theses on the topic 'Near infra-red spectroscopy (NIRS)'

Following a review of methods for measuring the optical properties of tissue, the majority of this thesis is concerned with the design, construction, calibration and use of a solid, tissue equivalent phantom. The phantom material is a clear polyester plastic. This is obtained in unpolymerised form, scattering particles and absorbing dyes are added to it, and it is then polymerised to form a stable solid. Purely scattering and absorbing phantoms were made separately, and their optical properties were measured using a specially built system. This has a co-linear collimated light source and detector, and measures the unscattered light transmitted through a sample as a function of its thickness. Other methods of measuring the optical coefficients of tissue were tested with this phantom. One of these uses integrating spheres to measure the transmitted and reflected light from a sample. A model of light transport (in this case a Monte Carlo model) is used to convert these measurements into scattering and absorption coefficients. It was found that the measurement of scattering coefficient was reasonably accurate, but that the absorption coefficient was overestimated at the low values typical of tissue. A measurement of the optical properties of bone was made with this system. The other system investigated uses the diffusion theory to calculate optical properties from measurements made through a thick slab. The material was also employed to create a test phantom for near infrared spectroscopy machines. This provides a diffusing medium with an attenuation that is variable in discrete steps over three orders of magnitude. The relative attenuation between steps is totally wavelength independent. This phantom was adopted by the EC concerted action on near infrared spectroscopy and imaging. Finally, the phantom was used to create test objects with which to investigate the potential of imaging with infrared light.

La complexité des médicaments biopharmaceutiques implique que leur validation par les instances réglementaires nécessite un processus spécifique. Tout changement, notamment du procédé, nécessite une nouvelle validation en termes d’efficacité clinique et de sécurité pour le patient. Puisque les changements dans le procédé sont parfois inévitables, la qualité du produit n’a plus à être évaluée uniquement en fin de procédé de production (Quality by testing, QbT), mais tout au long du procédé, et conceptualisée dans toutes les étapes de fabrication (Quality by Design, QbD). Cette démarche préconise de contrôler les paramètres critiques du procédé (CPP) en temps réel afin de maintenir les attributs de qualité critiques (CQA) dans une zone de confiance préalablement définie. Cependant, la mise en œuvre du QbD est actuellement limitée dans l’industrie biopharmaceutique en raison de la complexité des procédés de culture cellulaire ainsi que par la nécessité d’utiliser des méthodes d’analyse multivariée de données issues des analyseurs du procédé (i.e. méthodes spectroscopiques). L’objectif de ce travail a dont été de développer de nouvelles applications méthodologiques et expérimentales, basées sur la spectroscopie proche infrarouge (NIR) in situ, pour le suivi en temps réel de cultures de cellules produisant des biopharmaceutiques. Pour cela, deux modèles cellulaires ont été étudiés : des cellules de hamster chinois (CHO) produisant un anticorps monoclonal (mAb) et des cellules de plantes (Cantharanthus roseus) produisant des molécules anticancéreuses (la vincristine, VC et la vinblastine, VB). Dans un premier temps, un procédé permettant la production de VC et de VB a été développé. La différentiation cellulaire de Catharanthus roseus ayant été identifiée comme un CPP, son suivi en ligne a été rendu possible grâce à l’utilisation combinée de la spectroscopie NIR et de modèles de calibration basés sur la régression des moindres carrés partiels (PLS). Dans un second temps, pour les cultures de cellules CHO, différentes techniques de régressions ont été évaluées pour générer des modèles de calibration permettant le suivi en ligne des CPP et des CQA. La régression PLS s’est révélée inadéquate en raison de la variabilité chimique et physique que les cellules CHO entrainent durant les différentes phases de culture. Au contraire, la régression LWR (Local Weighted Regression) a permis de suivre en temps réel des CPP conventionnels (concentration en glucose, en lactate, en cellules vivantes,…). Cette régression permet de gérer de manière adéquate la variabilité associée à la culture cellulaire. Cependant, pour le suivi du profil de glycosylation des anticorps (CQA), cette régression n’est pas capable de gérer les relations non-linéaires existantes entre les spectres NIR et les concentrations en diverses formes d’anticorps glycosylés. Ce suivi en ligne des différentes glycoformes a été rendu possible uniquement par l’utilisation de la régression SVR (Support Vector Regressions). Ainsi, ce travail a permis l’amélioration du suivi en ligne de CPP par la spectroscopie NIR, mais également le suivi de nouveaux CPP comme l’état physiologique de cellules de plantes ou encore les différentes glycoformes des anticorps
The complexity of biopharmaceutical products implies that their approval is based on a specific process. Any further change, especially in the process, requires drug validation in terms of clinical effects and biosecurity. Because changes in the processes may be unavoidable, quality assurance by inspection at the end of the process (Quality by Testing-QbT) tends to be replaced by a new quality perspective called Quality by design (QbD) which builds drug Critical Quality Attributes (CQA) controlling key Critical Process Parameters (CPP) in real-time. However, QbD implementation has been limited by the complexity of cell culture processes and the need for multivariate methods that allow the use of complex signals from process analyzers as monitoring instruments. Consequently, the objective of this work has been to develop new methodological and experimental applications, based on in situ NIR spectroscopy, for real-time monitoring of biopharmaceutical-producing cell cultures using two production platforms: animal cells (CHO-250-9) producing monoclonal antibodies (mAb) and plant cells (Cantharanthus roseus) producing antineoplastic molecules (vincristine-VC and vinblastine-VB). First, a process capable of producing VC and VB was generated, cell differentiation was identified as CPP and the ability to monitor it by in situ NIR spectroscopy was firstly demonstrated using calibration models based on partial least squares regression (PLSR). Subsequently in CHO cell cultures, different regression techniques were evaluated to generate calibration models to monitor CPP and CQA. PLSR was inadequate because of the chemical and physical variability that CHO cell cultures present during the different phases of batch culture. Local Weighted Regression (LWR) was adequate to monitor classic CPP (concentration of glucose, lactate, and viable cells, amongst others) since it adequately handled the variability associated with the progression of cell culture. However, for the glycosylation profile (CQA), it was unable to properly handle the complex nonlinear relationships between NIR spectra and the concentration of various monoclonal antibody (mAb) glycoforms. This was overcome with the use of models based on support vector regressions (SVR), allowing the generation of models of different mAb glycoforms related to particular clinical effects. Globally, this work has contributed to the expansion of the capabilities of in situ NIR spectroscopy for the monitoring of classic CPP in a more precise way, new innovative CPP such as cell physiological state in plant suspension cultures, and CQA such as mAb glycosylation profiles linked to clinical characteristics in animal cell cultures

Incineration of waste materials has become a common way to handle a worldwide increase of produced waste materials. The problem with waste as fuel is that the material is not homogeneous and include a mixture of fossils and renewables. The fossil part ends up in an emission of fossil carbon dioxide in a combustion process, which is included in the emissions trading system. However, since waste material varies a lot in composition depending on the time of the year, origins, etc. it is preferable to have a method for real-time measurement of the fossil share of combusted waste. No real-time measurement technologies are available today which is the reason to investigate if near-infrared (NIR) spectroscopy could be a potential solution. An artificial mixture of refused derived fuel has been used to investigate the possibilities of NIR for prediction of the fossil share in waste material. The fossil share is assumed to be equal to the content of plastic material with an origin of oil products. Mixtures with different plastic content are scanned by the NIR instrument to obtain individual absorption spectra. A Partial least square (PLS) regression model is created on measured spectra and known content of plastics. The best model for the prediction on new spectral data using one of four measured replicates is a PLS model preprocessed with Savitzky-Golay smoothing that gives an R-square value of 0,782. If the prediction is done, depending on a delimitated wavenumber interval and an average of all four replicates is the best model instead of a PLS model pre-processed with standard normal variate without seven outliers that have an R-square value of 0,81. R-square value is the coefficient of determination which has been used to figure out the best model. An R-square value above 0,65 are recommended for process modelling, where 1 is the highest possible value.

Thesis (PhD(Agric) (Horticulture))--University of Stellenbosch, 2011.
Includes bibliography.
ENGLISH ABSTRACT: Plums with good taste, aroma and eating quality lead to repeat purchases and sustained demand. Taste includes non-volatile compounds, e.g. sugars and acids, and has been well researched to meet the consumers’ preferences. Plum aroma, however, has not enjoyed the same attention. Limited literature is available on the aroma of Japanese plums and none could be found on the effects of relatively long cold storage on the profiles. The main aim of this study is to investigate the changes in aroma compounds of Japanese plums throughout maturation and ripening and the effects of commercial cold storage regimes. Near infra-red (NIR) spectroscopy was also evaluated as a non-destructive method to determine plum quality parameters aimed at minimising sample variability. In Paper 1, NIR spectroscopy was used to develop prediction models for total soluble solid (TSS), total acidity (TA), sugar-to-acid ratio, firmness and weight in three cultivars (Pioneer, Laetitia and Angeleno) and a multi-cultivar model. Samples were collected for seven consecutive weeks and repeated over two seasons. TSS results showed excellent predictability (R2 = 0.817-0.955; RMSEP= 0.453-0.610 % Brix) but the TA models did not perform well. The sugar-to-acid ratio models had results comparable to that of TSS. Both the firmness and weight models had acceptable results. The models of ‘Pioneer’ and ‘Laetitia’ had a better predictability capacity than the ‘Angeleno’ model. Although the multi-cultivar models outperformed the single cultivar models on R2 values it had higher prediction errors. The robustness of all the TSS, TA and firmness models is high in terms of seasonality, range and cultivar. Papers 2 and 3, the main focus of the study, are concerned with the aroma profile dynamics of Japanese plums. HS-SPME was used in both papers to extract the aroma compounds followed by GC-TOFMS for separation and identification. In Paper 2, the aroma volatile compounds of three cultivars (Pioneer, Laetitia and Angeleno) were determined for a seven week period including samples from three maturity stages (immature, harvest and tree-ripe). A total of 35 compounds were identified of which ten were generic. Each cultivar had five unique compounds resulting in different aroma profiles for each of the maturity stages and distinct separation patterns using discriminant analysis. The study was extended in Paper 3 where the aroma volatile compounds of six cultivars (Pioneer, Sapphire, Laetitia, Songold, Larry Anne and Angeleno) and one plumcot (Flavor King) were determined at three functional stages (commercial harvest, tree-ripe fruit and cold stored fruit). A total of 62 compounds were identified and classified into three groups (‘unique’ (31), ‘generic’ (11) and ‘frequent’ (20)) based on their frequency of occurrence. The aroma profiles of ‘Larry Anne’ and ‘Flavor King’ are the most affected by cold storage conditions and ‘Pioneer’ appears to be the least affected. All the cultivars have significantly different aroma profiles at all three of the functional stages with ‘Sapphire’, ‘Larry Anne’ and ‘Flavor King’ showing the largest differences. ‘Flavor King’, a plumcot, presented a ripe aroma profile that was much diverged from that of the true plums.
AFRIKAANSE OPSOMMING: Pruime met ‘n goeie smaak, aroma en eetkwaliteit lei tot herhaalde verkope en volhoubare aanvraag. Smaak sluit die nie-vlugtige stowwe (suikers en sure) in en is goed nagevors om die verbruikersvoorkeure te bevredig. Pruim aroma het egter nie dieselfde aandag geniet nie. Daar is beperkte literatuur beskikbaar wat handel oor die aroma van Japanese pruime en geen kon gevind word oor die effekte van lang koelopberging op die aromaprofiele nie. Die hoof doel van hierdie studie is om die veranderinge in die aromatiese komponente van Japanese pruime te ondersoek tydens die volwassewording- en rypwordingsprosesse asook die effekte van kommersiele koelopberging. Naby infrarooi (NIR) spektroskopie is ook geevalueer as ‘n nie-destruktiewe manier om pruim kwaliteitsparameters te bepaal met die doel om monstervariasie te beperk. In Artikel 1 is NIR spektroskopie gebruik om voorspellingsmodelle vir totale oplosbare suikers (TOS), totale suur (TS), suiker-tot-suur verhouding, fermheid en gewig te bepaal in drie kultivars (Pioneer, Laetitia en Angeleno) asook ‘n multi-kultivar model. Monsters is vir sewe opeenvolgende weke versamel en herhaal oor twee seisoene. TOS resultate toon uitstekende voorspelbaarheid (R2 = 0.817-0.955; RMSEP= 0.453-0.610 % Brix) maar TS modelle het egter nie so goed gevaar nie. Die suiker-tot-suur verhoudingsmodelle se resultate was vergelykbaar met die van TOS. Beide die fermheid- en gewigsmodelle het aanvaarbare resultate opgelewer. Die modelle vir ‘Pioneer’ en ‘Laetitia’ het ‘n beter voorspelbaarheidskapasiteit getoon as die van ‘Angeleno’. Alhoewel die multi-kultivar model beter presteer het as die enkel kultivar modelle op die R2-waardes was daar meer voorspellingsfoute. Hoe robuustheid is gevind i.t.v. seisoene, datagrense en kultivar vir al die TOS, TA en fermheidsmodelle. Artikels 2 en 3, die fokuspunt van die studie, handel oor die dinamika van die aromaprofiel van Japanese pruime. HS-SPME is in beide artikels gebruik on die aromatiese verbindings te ekstraeer gevolg deur GCTOFMS vir skeiding en identifikasie. In Artikel 2 is die aromatiese stowwe van drie kultivars (Pioneer, Laetitia en Angeleno) bepaal vir sewe opeenvolgende weke en sluit monsters van drie volwassenheidsstadiums in (onvolwasse, oes en boom-rypgemaakte pruime). ‘n Totaal van 35 verbindings is geidentifiseer waarvan tien as generies beskou kan word. Elke kultivar het vyf unieke komponente gehad en het gelei tot verskillende aromaprofiele vir elk van die volwassenheidsstadiums en diverse skeidingspatrone tydens die gebruik van diskriminant analise. Die studie is uitgebrei in Artikel 3 waartydens die aromatiese vlugtige stowwe van ses kultivars (Pioneer, Sapphire, Laetitia, Songold, Larry Anne en Angeleno) en een plumcot (Flavor King) bepaal is tydens drie funksionele stadiums (oes, boom-rypgemaak en koelopgebergde pruime). ‘n Totaal van 62 verbindings is geidentifiseer en in drie groepe geklassifiseer (‘uniek’ (31), ‘generies’(11) en ‘gereeld’ (20)) gebaseer op voorkomsfrekwensie. Die aromaprofiele van ‘Larry Anne’ en ‘Flavor King’ is die meeste deur die koelopberging geaffekteer en ‘Pioneer’ die minste. Al die kultivars het kenmerkend verskil t.o.v. hul aromaprofiele in al drie die funksionele groepe en ‘Sapphire’, ‘Larry Anne’ en ‘Flavor King’ het die grootste verskille getoon. ‘Flavor King’, die plumcot, het ook ‘n ryp aromaprofiel gehad wat baie van die van die egte pruime verskil het.

Abstract Background: Intraoperative Near Infra-Red Spectroscopy (NIRS) may reduce postoperative neurologic complications. Use in pediatric populations, NIRS increases, and variations in sensor placement are understudied. Objective: To explore NIRS performance in a pediatric population undergoing cardiac surgery; to describe significant (20%) NIRS deviations from baseline; to correlate events with physiologic variables; to examine the relevance of a second sensor. Methods: Retrospective review of prospectively collected NIRS data. Associations were assessed using Student's t-test, chi-squared test and logistic regression. Results: Significant deviations from baseline were common. Many occurred when unsupported by CPB (cardiopulmonary bypass) or upon CPB initiation. NIRS decreases and increases were significantly associated with PaO2, hematocrit, and MAP (mean arterial pressure) (p<0.05) and paCO2 (p<0.01), respectively. Unilateral deviations were frequent, particularly amongst cyanotic and male patients. Conclusion: In this population, significant NIRS deviations are associated with physiologic variables. A second sensor provided significant information.
Introduction: Le Near Infra-Red Spectroscopy (NIRS) utilitisé durant la période opératoire peut réduire les complications neurologiques postopératoires. L'utilisation du NIRS chez la population pédiatrique et les variations associées au placement des senseurs sont sous étudiées. Objectifs: Explorer les performances du NIRS chez les enfants lors de chirurgies cardiaques; décrire les variations significatives du NIRS (20%) en comparaison aux niveaux témoins; établir des corrélations entre les événements et les variables mesurées; établir l'utilité d'un second senseur. Méthodes: Une revue rétrospective de données NIRS obtenues de façon prospective. Les relations observées seront évaluées avec les tests Student-t, chi-squared, et de régression logistique. Résultats: Des variations significatives en comparaison aux valeurs témoins ont été observées. Plusieurs de ces variations ont eu lieu lorsque les patients n'étaient pas supportés par la circulation extracorporelle ou lors de son initiation. Les augmentations et diminutions du NIRS sont significativement reliées au PaO2, à l'hématocrite, à la pression artérielle moyenne (p<0.05) et au paCO2 (p<0.01), respectivement. Des variations unilatérales du NIRS sont fréquentes, particulièrement chez les patients cyanosés et chez les patients males. Conclusion: Chez cette population pédiatrique, des déviations significatives du NIRS sont associées à certaines variables physiologiques. Le deuxième senseur ajoute des informations utiles.

In an attempt to reduce the costs and turn around times experienced with outsourcing starch analysis in finished feed products, the company decided to invest in a NIR instrument to carry out such analyses in house. The particular instrument purchased by the company comes with a build in calibration for specific finished feed products and the main objective of this investigation was to evaluate whether the instrumentation and build in calibration gives reliable analyses of a finished poultry feed. The results obtained showed that : - The NIR results obtained have a positive bias compared to the theoretical (formulation specified value) and also to the value obtained by enzymatic starch analysis. - Despite the positive bias, the starch values were well within the allowable limits - Repeatability measurements on the data generated by two different analysts showed that while the percentage relative standard deviations obtained (< 1.0 percent) were well within the company specifications of percentage RSD < 5.0 percent, the inter sample repeatability showed small, but significant variation. - The results for intermediate precision showed that there is no statistically significant difference between the results obtained by two different analysts, nor was there any difference in the results of the same samples analysed at different time periods. - Reproducibility could not be evaluated due to the lack of another instrument within the company that were similarly set up as the instrument used for the investigation. This investigation has shown that, given the restrictions enforced by the build incalibration of the NIR instrument, the use of NIR for the analyses of the finished feed product is valid, but will require that careful attention be paid to data collection procedures.

This thesis describes a set of studies of the use of near infrared spectroscopy to measure cerebral oxygenation in obstructive sleep apnea (OSA) and chronic hypoxia. Cerebral oxygenation depends on cerebral blood flow and arterial oxygen saturation. The hypothesis underlying these studies was whether measurement of cerebral oxygenation using near infra-red spectroscopy (MRS) gives additional valid information compared to measuring arterial oxygen saturation alone. We also hypothesized that this technique could be used to assess overnight cerebral oxygenation in sleep studies. Our first validation study in 13 subjects with significant OS A showed that the fall in cerebral tissue saturation (measured as tissue oxygenation index, TO I) during sleep apnoea is related to arterial saturation (Sa02) (p=0.012), apnoea duration (p=0.001) and sleep stage (p<0.001) in a multiple regression in 1036 apnoeas. We also demonstrated changes in cerebral blood volume (range 0.41 - 0.09 ml/lOOg) and cytochrome oxidase oxidation state (range 0.48 - 0.13uM) occurring during apnoeas in 8 of these subjects. In a second validation study in 8 subjects we demonstrated correlations between changes in TOI and both arterial saturation (p=0.001), apnoea duration (p=0.001) and cerebral blood flow velocity (p=0.012) measured using carotid Doppler. We derived area under the curve (AUC) measures and dip rates for TOI and Sa02 during overnight studies and compared them to conventional polysomnographic measures, showing significant correlations of pretreatment apnoea hypopnoea index (AHI) with dip rates for both TOI and Sa02. AUC TOI correlations with pretreatment AHI were weak. Mean AUC for TOI was 339.4 (161-675) and mean AUC for Sa02 was 308.5 (89-944). Mean 4% Sa02 dip rate was 32.6 (1.5-90.6) and mean 4% TOI dip rate was 24 (0.1-95.7). Pilot studies were also carried out on 11 subjects with chronic obstructive pulmonary disease (COPD) during oxygen challenge. Calculated cerebral blood volume measurements varied from 1.51 ml/lOOg to 3.65 ml/lOOg. Changes in TOI in response to supplementary oxygen in patients with COPD and chronic hypoxia are related to both cerebral blood volume (p=0.001) and arterial saturation (p=0.001). The most important new findings in these studies are that cerebral blood flow changes appear to exacerbate rather than compensate for arterial hypoxia during sleep apnoea, and so it is plausible that TOI measurement (which picks up both Sa02 and cerebral blood flow velocity (CBFV) changes) may be more closely related to changes in neuropsychological function than pulse oximetry. The changes in cerebral oxygenation are profound enough to affect intracerebral redox state measured as cytochrome oxidase oxidation. Pilot work in COPD patients suggests that changes in cerebral blood volume affecting cerebral oxygenation occur during supplementary oxygen administration. NIRS provides a non-invasive method of measuring cerebral oxygenation suitable for use in sleep studies, and during oxygen administration.

Thesis (M.Sc.) - Swinburne University of Technology, Brain Sciences Institute, 2008.
A thesis submitted for M.Sc by Research, Brain Sciences Institute, Swinburne University of Technology - 2008. Typescript. Includes bibliographical references (p. 117-153)

O grande desafio da Implantodontia é alcançar resultados a longo prazo com maior preservação dos tecidos ósseos, resposta adequada dos tecidos conjuntivos e manutenção da estabilidade secundária adequada para a retenção de próteses. Estes fatores evitam a perda indesejável tanto do tratamento reabilitador quanto dos tecidos ósseos de suporte. A região extraoral apresenta menores espessuras ósseas em comparação às regiões de maxila e mandíbula, especialmente no osso temporal. Portanto, os seguintes aspectos foram investigados: (i) Análise pelo Método dos Elementos Finitos (FEA) de 16 modelos virtuais, com aplicação de forças estáticas de tensão e compressão nos pontos médios entre os implantes. Três implantes maxilofaciais extraorais foram posicionados no osso temporal, onde um deles foi posicionado sobre o processo mastóide. Este estudo foi totalmente realizado em ambiente computacional. Foram empregados dois tipos de conexões protéticas e intermediários retos de conicidades 20º e 45º, posicionados virtualmente no modelo de osso temporal, com paralelismo entre eles. Foi desenhada uma barra virtual para retenção protética do tipo barra-clipe da prótese auricular. Foram consideradas as melhores configurações aquelas apresentando distribuição uniforme e branda das tensões de von Mises sobre o tecido ósseo adjacente aos implantes. (ii) Confecção de corpos de prova com graus variáveis de pigmentação para (a) melhorar a reprodutibilidade da coloração (b) entender e reduzir o processo de descoloração para melhorar a longevidade das próteses. Um elastômero maxilofacial tipo A foi pigmentado intrinsecamente de acordo com os seis tons da Escala de Fitzpatrick. Uma técnica de pigmentação foi desenvolvida a partir dos resultados obtidos a partir de uma Escala de Fitzpatrick impressa em papel e dos pigmentos intrínsecos de cores primárias. Este dimetil-metilvinil-siloxano reforçado por platina A 223-30 (Factor II, Inc., Lakeside, AZ, USA) apresenta dureza \"Shore-A\" 30. As amostras foram expostas a fotoenvelhecimento acelerado, e sua degradação mapeada com Espectroscopia UV/Vis/NIR. Concluiu-se que: (i) Os implantes com conexão cone Morse plataforma 3.7 tem melhor comportamento biomecânico com intermediários de 45o e altura de 2mm. Sugere-se planejamento cirúrgico visando a instalação a 3 horas para o temporal esquerdo e 9 horas para o temporal direito, mais 6 horas (mastóide). Implantes com conexão cone Morse plataforma 4.0 apresentaram comportamento biomecânico desejável com intermediários de 20o e alturas de 2mm or 4mm. Para implantes com conexão cone Morse plataforma 4.0, sugere-se a instalação a 6-9-12 horas para o temporal direito, e 12-6-3 para o esquerdo, visando comportamento biomecânico adequado. Sugere-se que os implantes extraorais Brånemark hexágono externo com plataforma 4.1 regular ou expandida sejam preferencialmente empregados com intermediários de 20o. (ii) O SiO2 5% pode ser adicionado à preparação do silicone para retardar o desbotamento da prótese maxilofacial. O TiO2 traz mudanças visuais significativas e pode ser considerado como opacificador.
Major challenges in Implantology include: achieving longevity of implants, bone tissue preservation, connective tissue suitable answer and maintenance of secondary stability in order to retain prosthesis. These factors avoid the undesirable loss of both rehabilitation treatment and supporting bone tissues. The extraoral region has less bone depth compared to the maxilla and mandible regions, especially for the temporal bone. Therefore, the following aspects were investigated: (i) Finite Elements Analysis (FEA) of 16 virtual models, with static application of tension and compression forces in medium points between implants. Three extraoral maxillofacial implants were placed on the temporal bone, which one of them was placed on the mastoid process. This study was made entirely in a computational environment. Two prosthetic connection types and straight Intermediários were employed, with conicities of 20º and 45º, placed virtually on the temporal bone model, mutually parallel. A virtual bar for bar-clip prosthetic retention of auricular prosthesis was designed. The best configurations were considered to be the ones presenting uniform and mild von Mises tension distribution over the bone tissue around the implants. (ii) Generation of samples with varying degree of pigmentation to (a) improve the reproducibility of the colouration (b) understand and minimise the discolouration process to improve prosthetics longevity. A maxillofacial elastomer type A was intrinsically pigmented according to the six tones of the Fitzpatrick Scale. A pigmentation technique was developed from spectroscopy outcomes of paper printed Fitzpatrick Scale and the primary colors pigments. This platinum reinforced dimethyl methylvinyl siloxane A 223-30 (Factor II, Inc., Lakeside, AZ, USA) presents \"Shore-A\" hardness 30. The samples were exposed to accelerated photo aging, and their degradation mapped with UV/Vis/NIR Spectroscopy. The effects of exclusion of oxygen and inclusion of nanoparticle fillers during prosthetic formulation were investigated. It was concluded that: (i) Morse taper prosthetic connection 3.7 platform implants, should be employed with 45o abutments with 2mm height. The surgical planning shall be for placement 3 hours for the left temporal bone and 9 hours for the right, and in 6 hours (mastoid). Morse taper prosthetic connection 4.0 platform implants behaved biomechanically desirably with 20o abutments in 2mm or 4mm heights. For the Morse taper connection 4.0 platform implants, their placement shall be in 6-9-12 hours, for the right temporal, and 12-3-6, for the left temporal, in order to achieve proper biomechanical behaviour. The Brånemark extraoral external hexagon implant, with 4.1 platform (normal or expanded) should preferrably be used with 20o abutments. (ii) The SiO2 5% may be added to the silicone preparation in order to slow maxillofacial prosthesis colour fading. The TiO2 brings visually significant changes and may be considered as an opacifier.

Background: Traumatic brain injury (TBI) is pathology of growing international importance. Near Infrared spectroscopy (NIRS) represents a non-invasive, cost effective and easily applies cerebral tissue monitoring modality with the potential to direct therapy and guide management decisions. Currently the use of this technology within mainstream TBI care is limited considering its potential inherent advantages. Recent advances in NIRS parameter recovery techniques and data processing potentially offer an improvement on previously evaluated technology. Frequency domain (FD) parameter recovery NIRS is one such advancement now available in clinically viable and commercially available devices. This technology has not yet been evaluated within the context of TBI care. Aims: i) To assess the current evidence within the published literature regarding the use of NIRS within the field of TBI management. ii) To compare the abilities of a frequency domain clinically viable point of care NIRS device to radiological and invasive gold standards in measuring changes in cerebral physiology. Methods: A number of specific original investigations to assess the abilities of clinically viable NIRS technology benefiting from FD parameter recovery for use in the management of TBI patients were undertaken along with a review of the existing literature. Results. NIR.S has demonstrated certain useful abilities in the monitoring of cerebral oxygenation in the care of individuals who have sustained a TBI, however sufficient evidence does not exist to support its independent use in TBI. The FD NIRS device tested demonstrated good correlation with fMRI (Valsalva and Hyperventilation), and equivalent abilities in differentiating activity within superficial extra-cranial and cerebral tissue. Manipulating of blood flow into the overlying extra-cranial tissue did not significantly affect the output parameters seen in these models. However the FD NIRS device tested did not demonstrate sufficient abilities to replace invasive brain tissue oxygen tension measurement in TBI patients. Also, within the context of controlled hypoxia (relevant to TBI) no discernable advantage was observed in utilising a device benefiting from frequency domain parameter recovery. Conclusion: NIRS still remains the best available prospect for a non-invasive monitoring modality to direct therapy and guide management in TBI care. However, further development and translation of the multitude of advancements in NIRS technology achieved recently in the science of biological optics may be required to realise this potential.

A la phase aigüe des accidents ischémiques cérébraux, l'objectif thérapeutique principal est l'obtention d'une recanalisation de l'artère occluse et d'une reperfusion de la zone de pénombre ischémique. L'identification de facteurs prédictifs d'une recanalisation et le développement de nouveaux outils de surveillance est d'un intérêt majeur lors de la mise en oeuvre de ces thérapeutiques. Dans la première partie de notre travail, nous avons étudié la valeur pronostique de la visibilité initiale du thrombus sur les séquences IRM en T2* et son évolution lors d'acquisitions séquentielles chez les patients traités par thrombolyse intraveineuse. Nous avons confirmé la valeur péjorative cette visibilité initiale, et souligné les discordances entre les données de l'angioIRM et de la séquence T2* lors de l'analyse séquentielle. Dans la seconde partie du travail, nous avons évalué l'intérêt de la spectroscopie de proche infrarouge comme méthode permettant d'évaluer le bénéfice de la recanalisation chez les patients traités par thrombectomie mécanique. Cette technologie semble intéressante, mais présente cependant des limites discutées dans ce travail
Acute ischemic stroke treatments (intravenous thrombolysis, mechanical thrombectomy) aim to restore an affective brain perfusion in order to improve neurological outcome. We first evaluated the predictive value of susceptibility vessel sign (SVS) on T2* MRI sequence after intravenous thrombolysis and studied course of SVS using sequential MRI assessment. We confirm that SVS is a strong predictor of no recanalisation, and underline discrepancies between MR angiography and T2* data. In the second part, we assessed the usefulness of near-infrared spectroscopy (NIRS) to monitor recanalisation during mechanical thrombectomy. NIRS is a reliable tool, but still suffer of challenging limitations

Implication de l’oxygénation cérébrale dans les limitations à l’exercice musculaire des personnes non-entraînées et sportifs d’endurance. L’objectif général de ce travail était de déterminer si l’oxygénation cérébrale était un facteur de la limitation à l’exercice de type aérobie. Dans un premier temps, nous nous sommes attachés à étudier le rôle de l’oxygénation cérébrale mesurée par la Spectroscopie dans le proche Infra-Rouge (NIRS) dans la limitation de l’exercice progressif maximal en rampe. Nous avons montré l’existence d’un seuil de déclin de l’oxygénation cérébrale associé au point de compensation respiratoire (RCP). L’amélioration de la performance avec une supplémentation d’O2 était liée au décalage de ce seuil à de plus hautes intensités d’exercice chez des sujets actifs (étude 1). Dans un second temps, nous avons montré que ce seuil de déclin de l’oxygénation, retrouvé aussi chez des sportifs entraînés en endurance apparaîssait à de plus hautes intensités d’exercice que chez des sujets non-entraînés (étude 2). Enfin, nous avons déterminé l’impact de l’hypoxémie artérielle induite par l’exercice (HIE) des sportifs d’endurance sur l’oxygénation cérébrale au cours d’un exercice maximal en rampe et d’un exercice de temps limite à charge constante. Nous avons ainsi montré que l’oxygénation cérébrale était augmentée avec la HIE suggérant un effet compensatoire à l’hypoxémie artérielle au cours de l’exercice progressif maximal en rampe. Ceci, n’existait pas au cours de l’exercice de temps limite ne supportant pas l’implication de l’oxygénation cérébrale dans ce type d’exercice (étude 3). Ces travaux ont donc mis en évidence l’implication de l’oxygénation cérébrale dans la limitation de l’exercice maximal en rampe chez des sujets actifs et des sportifs entraînés en endurance présentant ou pas une HIE. Toutefois, elle ne semble pas être un facteur majeur de limitation de l’exercice de temps limite
Involvement of cerebral oxygenation in muscular exercice limitation in untrained and trained endurance men. A decrease in oxygen availability in the brain could be a physiological mechanism limiting aerobic fitness. We first studied the role of cerebral oxygenation measured by Near Infra-Red Spectroscopy (NIRS ) in maximal cycle ramp exercise limitation. We showed a cerebral oxygenation threshold decline associated with respiratory compensation point (RCP). This threshold appeared for higher exercise intensities -related to performance improvement with hyperoxia in untrained endurance men (study 1). Secondly , we showed that the cerebral oxygenation threshold in athletes occurred for higher sub-maximal exercise intensities than untrained (study 2). Finally , we determined the involvement of exercise-induced arterial hypoxemia (EIH) in endurance athletes on cerebral oxygenation during maximal cycle ramp exercice and exercice time to exhaustion. We showed that cerebral oxygenation was improved by EIH suggesting a compensatory effect of EIH during the maximal cycle ramp. This did not occur during exercise time to exhaustion, and does not support the involvment of cerebral oxygenation in this type of exercise (study 3). This work has therefore highlighted the involvement of cerebral oxygenation in maximal cycle ramp exercice limitation in untrained and trained endurance men with or without EIH. However, it was unlikely been the major factor limiting the exercise time to exhaustion

Submitted by Aelson Maciera (aelsoncm@terra.com.br) on 2017-05-15T19:57:24Z No. of bitstreams: 1 TeseCOF.pdf: 3178869 bytes, checksum: cfad2da3f19b56d42e09c4a472158572 (MD5)
Approved for entry into archive by Ronildo Prado (bco.producao.intelectual@gmail.com) on 2018-02-01T10:55:05Z (GMT) No. of bitstreams: 1 TeseCOF.pdf: 3178869 bytes, checksum: cfad2da3f19b56d42e09c4a472158572 (MD5)
Approved for entry into archive by Ronildo Prado (bco.producao.intelectual@gmail.com) on 2018-02-01T10:55:19Z (GMT) No. of bitstreams: 1 TeseCOF.pdf: 3178869 bytes, checksum: cfad2da3f19b56d42e09c4a472158572 (MD5)
Made available in DSpace on 2018-02-01T11:06:54Z (GMT). No. of bitstreams: 1 TeseCOF.pdf: 3178869 bytes, checksum: cfad2da3f19b56d42e09c4a472158572 (MD5) Previous issue date: 2016-06-24
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Type 2 diabetes mellitus (DM) is responsible for quality of life reduction due its negative impact in the physical exercise capacity. The impairment of cardiopulmonary fitness and lower values in oxygen uptake in exercise tests has been associated with factors related with diabetes complications. Phototherapy is a resource largely utilized due it action in biological systems and it may be adjuvant to exercise to improve muscular efficiency and increase aerobic capacity. Thus, the question if this resource may be benefit to populations with DM. Therefore, we proposed a study protocol randomized, double-blind, placebo controlled to evaluate the acute effect of light emitting diode (LED) in cardiorespiratory and hemodynamic adjustments of moderate exercise in cycloergometer, as well as, in lactate and glucose levels pre and post intervention and after exercise in men aged between 45 and 64 years, with DM and health. Then, two studies were performed. In the study 1 it was evaluated the acute effect of phototherapy (LED-150J) in two groups: DM group (DMG) and health group (HG) (n=16 and n=9, respectively). The groups were paired by age and body mass index. The LED reduced significantly the glucose levels in DMG after exercise and do not affect the lactate levels, cardiorespiratory and hemodynamic adjustments of aerobic exercise in both groups. Our results suggest that LED in combination with moderate exercise decrease acutely the glucose levels in adult subjects with DM. The study 2 aimed evaluate the acute effect of two different doses of phototherapy. Participated in this study two groups of men with DM: LED-150J (n=16) and LED-300J (n=17). The LED-150J reduced the levels of glucose after exercise. The LED-300J increased the lactate levels after exercise in effective session compared with placebo. Any doses changed the cardiorespiratory and hemodynamic adjustments. This study demonstrated that the phototherapy with LED using the 300J dose did not improved the parameters studied and the 150J dose improved the glycaemia and should be used in combination with other therapies for the hyperglycemia management in individuals with DM. The general conclusion of this thesis is that our findings suggest that phototherapy associated with moderate physical exercise have therapeutic potential to control glycaemia in DM, however, further studies should be conducted investigating the dose window and dose-response capable to change acutely the cardiopulmonary and hemodynamic adjustments and lactate levels.
O diabetes mellitus tipo 2 (DM) é responsável por redução significativa na qualidade de vida devido ao seu impacto negativo na capacidade de realização de exercícios físicos. A diminuição do condicionamento cardiopulmonar e os menores valores de consumo de oxigênio pico em testes de exercício têm sido associados com múltiplos fatores envolvidos nas complicações do diabetes. A fototerapia é um recurso que tem sido utilizado devido sua ação nos sistemas biológicos, podendo ser um coadjuvante do exercício na melhora da eficiência do trabalho muscular e aumento da capacidade aeróbia. Por isso, levantou-se a questão de que tal recurso poderia beneficiar populações com DM. Assim, foi proposto um protocolo experimental aleatorizado e duplo-cego visando avaliar o efeito agudo da fototerapia com diodos emissores de luz (LED) nos ajustes cardiorrespiratórios e hemodinâmicos ao exercício moderado em cicloergômetro, bem como nas concentrações de lactato e glicose sanguíneas pré e pós intervenção e após o exercício físico em homens com DM e saudáveis, com idade entre 45 e 64 anos. A partir deste protocolo dois estudos foram realizados. No estudo 1 foi avaliado o efeito agudo da fototerapia (LED-150J) em dois grupos: grupo com DM (GDM, n=16) e grupo saudável (GS, n=9). Os grupos foram pareados por idade e índice de massa corpórea. O LED reduziu significativamente as concentrações de glicose no GDM após o exercício em cicloergômetro e não afetou os níveis de lactato e os ajustes cardiorrespiratórios e hemodinâmicos em ambos os grupos. Nossos resultados sugerem que o LED em combinação com o exercício moderado reduz de forma aguda os níveis de glicose em homens adultos com DM. No estudo 2 objetivou-se avaliar o efeito agudo de duas diferentes doses de fototerapia. Participaram desse estudo dois grupos de homens com DM: LED-150J (n=16) e LED-300J (n=17). O LED-150J reduziu as concentrações de glicose após o exercício físico e o LED-300J aumentou os níveis de lactato após o protocolo de exercício na fototerapia efetiva em comparação com a fototerapia placebo. Nenhuma das dosagens avaliadas modificou significativamente os ajustes cardiopulmonares e hemodinâmicos avaliados. Este estudo mostrou que a fototerapia por meio de LED na dosagem de 300J não causou melhora nos parâmetros estudados enquanto a dosagem de 150J melhorou a glicemia, podendo ser utilizada como recurso adjuvante no controle da hiperglicemia em indivíduos com DM. Como conclusão geral, nossos achados sugerem que a fototerapia associada ao exercício moderado tem potencial terapêutico no controle da glicemia do DM, no entanto, mais estudos são necessários para estabelecer a janela terapêutica e a dose-resposta capaz de modificar de forma aguda os ajustes cardiopulmonares e hemodinâmicos, assim como os níveis de lactato.
FAPESP: 2013/08183-7
FAPESP: 2015/20512-1
FAPESP: BEPE 2013/07953-3

Yes
The use of near infra red spectroscopy to predict the concentration of two pharmaceutical co-crystals; 1:1 ibuprofen – nicotinamide (IBU-NIC) and 1:1 carbamazepine – nicotinamide (CBZ-NIC) has been evaluated. A Partial Least Squares (PLS) regression model was developed for both co-crystal pairs using sets of standard samples to create calibration and validation data sets with which to build and validate the models. Parameters such as the root mean square error of calibration (RMSEC), root mean square error of prediction (RMSEP) and correlation coefficient were used to assess the accuracy and linearity of the models. Accurate PLS regression models were created for both co-crystal pairs which can be used to predict the co-crystal concentration in a powder mixture of the co-crystal and the active pharmaceutical ingredient (API). The IBU-NIC model had smaller errors than the CBZ-NIC model, possibly due to the complex CBZ-NIC spectra which could reflect the different arrangement of hydrogen bonding associated with the co-crystal compared to the IBU-NIC co-crystal. These results suggest that NIR spectroscopy can be used as a PAT tool during a variety of pharmaceutical co-crystal manufacturing methods and the presented data will facilitate future offline and in-line NIR studies involving pharmaceutical co-crystals.

O presente trabalho teve como objectivo proceder à avaliação da qualidade nutricional de 20 variedades regionais de Phaseolus vulgaris L. e à análise comparativa dos parâmetros bioquímicos (nutricionais e anti-nutricionais) obtidos recorrendo às técnicas analíticas convencionais por química molhada e de NIRS (Near Infra-Red Spectroscopy). Uma tipificação das variedades regionais de feijão foi realizada recorrendo a sete parâmetros ou caracteres (traits) nutricionais compreendidos em humidade, proteína bruta, lípidos totais, açúcares solúveis, amido, cinzas e minerais. A faseolamina foi incluída na tipificação do feijão como parâmetro anti-nutricional enquanto inibidor de enzimas digestivas. A variedade que apresentou uma melhor qualidade nutricional foi o feijão vermelho (ISOP 00724), enquanto que o feijão Filipe (ISOP 00478) apresentou uma maior actividade inibitória da PPA (amilase do pâncreas suíno), contribuindo de igual forma como uma característica de qualidade deste feijão. A aplicação de técnicas de quimiometria na quantificação dos vários parâmetros de qualidade nutricional, através da técnica de NIRS, permitiu o desenvolvimento dos modelos PLS globais após a colecção dos valores de referência e obtenção dos respectivos espectros de cada ISOP em análise. A análise comparativa dos parâmetros nutricionais, recorrendo às técnicas analíticas convencionais por química molhada e de NIRS, permitiu relacionar os parâmetros cinzas e proteína bruta como os principais critérios nutricionais para distinção das variedades regionais quanto à sua qualidade, ao diferirem significativamente relativamente aos parâmetros restantes. A partir destas duas técnicas, conclui-se que a espectroscopia NIR associada a técnicas de análise multivariada consegue quantificar os parâmetros em estudo, permitindo distinguir amostras das variedades regionais, quanto às suas características nutricionais, exigindo uma preparação reduzida da amostra, com consequente custo de análise muito reduzido. Este trabalho representou o início de uma base de fenotipagem a partir de caracteres nutricionais, estabelecendo-se um perfil das variedades regionais de feijão e avaliação da importância dos caracteres na sua distinção e tipagem.
Univerdade da Madeira

Este trabalho foi desenvolvido com o intuito de avaliar nutricionalmente variedades agrícolas regionais madeirenses e açorianas de Ipomoea batatas L. (batata-doce). No total 18 amostras foram analisadas, entre as quais 11 são variedades provindas da Madeira e outras 7 provindas dos Açores. O maior objectivo deste estudo foi comparar a composição nutricional e mineral de um conjunto de variedades de batata-doce, valorizando assim os recursos agrícolas da Madeira e Açores. A caracterização nutricional e mineral dos rizomas, produzidos nestas regiões, proporcionou informação relevante para a valorização destes recursos. Sendo um rizoma tropical consumido habitualmente pela população e disponível todo o ano, torna essencial a sua avaliação. A análise laboratorial dos rizomas permitiu determinar um conjunto de características nutricionais. De um modo geral, os valores nutricionais médios detectados em rizomas de batata-doce destas duas regiões são de 93,64 g/100g de MS para o resíduo seco, 3,01 g/100g de MS para cinzas, 3,19 g/100g de MS para fibra (ADF), 1,21 g/100g de MS para gordura bruta, 3,20 g/100g de MS para proteína, 14,00 g/100g de MS para açúcares solúveis e 59,72 g/100g de MS para o amido. A análise mineral incluiu a determinação de fósforo, potássio, cálcio, magnésio, ferro, cobre, zinco, manganês e boro. Na variedade “De cenoura” (ISOP 1028), foi quantificado o nível de pro-vitamina A pela técnica de HPLC, que foi verificado ser 12,48 mg/100g em MS de β-caroteno. Os dados obtidos na análise nutricional foram usados para construir uma base de dados no NIRS (Near Infra-Red Spectroscopy) de modo a construir um modelo de previsão que possa predizer o valor nutritivo de um grande número de amostras em tempo reduzido, com um mínimo de impacto ambiental. Posteriormente, os dados obtidos através das análises nutricionais e minerais foram introduzidos no software estatístico SPSS 19.0 para determinar correlações e similaridades.
Universidade da Madeira

Predictive models based on near infra-red spectroscopy for the assessment of fruit internal quality attributes must exhibit a degree of robustness across the parameters of variety, district and time to be of practical use in fruit grading. At the time this thesis was initiated, while there were a number of published reports on the development of near infra-red based calibration models for the assessment of internal quality attributes of intact fruit, there were no reports of the reliability ("robustness") of such models across time, cultivars or growing regions. As existing published reports varied in instrumentation employed, a re-analysis of existing data was not possible.

An instrument platform, based on partial transmittance optics, a halogen light source and a (Zeiss MMS1) detector operating in the short wavelength near infra-red region was developed for use in the assessment of intact fruit. This platform was used to assess populations of macadamia kernels, melons and mandarin fruit for total soluble solids, dry matter and oil concentration. Calibration procedures were optimised and robustness assessed across growing areas, time of harvest, season and variety. In general, global modified partial least squares regression (MPLS) calibration models based on derivatised absorbance data were better than either multiple linear regression or 'local' MPLS models in the prediction of independent validation populations. Robustness was most affected by growing season, relative to the growing district or variety. Various calibration updating procedures were evaluated in terms of calibration robustness. Random selection of samples from the validation population for addition to the calibration population was equivalent to or better than other methods of sample addition (methods based on the Mahalanobis distance of samples from either the centroid of the population or neighbourhood samples). In these exercises the global Mahalanobis distance (GH) was calculated using the scores and loadings from the calibration population on the independent validation population. In practice, it is recommended that model predictive performance be monitored in terms of predicted sample GH, with model updating using as few as 10 samples from the new population undertaken when the average GH value exceeds 1.0.

Ce mémoire est séparé en deux volets, tous deux axés sur la spectroscopie proche infra-rouge (NIRS) pour la quantification des paramètres hémodynamiques. La NIRS est principalement basée sur la mesure des coefficients d'absorption (μa) et de dispersion (μs’) des tissus afin de retrouver les concentrations d'oxy- et de déoxyhémoglobine dans le sang. L'imagerie à l'aide de la NIRS est basée sur le parcours des photons à travers le tissu biologique à différentes longueurs d'onde du spectre proche infra-rouge. Le premier appareil de NIRS dont il sera question est un appareil de spectroscopie résolue dans le temps. Ce type de système retrouve des concentrations absolues d'hémoglobine à l'aide d'un bandeau placé sur la peau d’un sujet, dans ce cas-ci sur le front. Le modèle d’analyse des données permet la séparation des contributions extra-cérébrales et cérébrales aux données. Cette méthode fournit des données plus exactes sur la saturation en oxygène du cerveau, par rapport à un modèle homogène où le signal est contaminé par les couches superficielles. Une étude sur les changements hémodynamiques cérébraux de jeunes adultes pendant une activité physique a été réalisée, et l’article en détaillant les résultats est transcrit au chapitre 2. Le chapitre 3 comprend un retour sur cette étude et aborde les possibilités de travaux futurs. La seconde partie de mes travaux s’est déroulée sous forme de stage en entreprise durant l’été 2016. Sous la supervision de Dennis Hueber, Ph. D., et Beniamino Barbieri, Ph. D., j’ai effectué des recherches portant sur un appareil de NIRS manufacturé par la compagnie ISS Inc. et dont un prototype se trouve actuellement dans le laboratoire de mon superviseur Mathieu Dehaes, Ph. D. Cet appareil combine deux modalités d’imagerie optique, soit la NIRS dans le domaine des fréquences et la spectroscopie de corrélation diffuse. Le chapitre 4 détaille les tâches que j’ai réalisées durant ce temps, de même que les résultats des analyses que j’ai effectuées.
This master’s thesis is separated in two phases, both focused on near infrared spectroscopy for the quantification of hemodynamic parameters. NIRS is based on the measure of absorption (μa) and scattering (μs’) coefficients of tissues in order to recover the oxy- and deoxyhemoglobin concentrations in the blood. Its results are based on the photon propagation in tissue at different near-infrared wavelengths. The first NIRS system used during my studies is a time-resolved spectroscopy system. This device allowed us to retrieve absolute hemoglobin concentrations using a headband placed over the subject’s skin and centered on their forehead. The data analysis model which we used allowed us to separate extra-cerebral and cerebral contributions of the signal. This method yielded quantitative absolute measures of cerebral oxygen saturation as opposed to the traditional homogenous model where the signal is contaminated by superficial layers. A study on cerebral hemodynamic changes in young adults during exercise was conducted, and the published article detailing its results is transcribed in Chapter 2. Chapter 3 includes a review of this study and discusses potential future works. The second part of my research consisted in an industrial internship during the summer of 2016. Under the supervision of Dennis Hueber, Ph. D., and Beniamino Barbieri, Ph. D., I have worked on a NIRS device manufactured by ISS Inc., a prototype of which is currently in the laboratory of my supervisor Mathieu Dehaes, Ph. D. This device combines two NIRS modalities: frequency-domain NIRS and diffuse correlation spectroscopy. Chapter 4 details the work I have performed at ISS and the results of my research and analysis.