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Using prerecorded hemodynamic response functions in detecting prefrontal pain response: a functional near-infrared spectroscopy study
摘要： Currently, there is no method for providing a nonverbal objective assessment of pain. Recent work using functional near-infrared spectroscopy (fNIRS) has revealed its potential for objective measures. We conducted two fNIRS scans separated by 30 min and measured the hemodynamic response to the electrical noxious and innocuous stimuli over the anterior prefrontal cortex (aPFC) in 14 subjects. Based on the estimated hemodynamic response functions (HRFs), we first evaluated the test–retest reliability of using fNIRS in measuring the pain response over the aPFC. We then proposed a general linear model (GLM)-based detection model that employs the subject-specific HRFs from the first scan to detect the pain response in the second scan. Our results indicate that fNIRS has a reasonable reliability in detecting the hemodynamic changes associated with noxious events, especially in the medial portion of the aPFC. Compared with a standard HRF with a fixed shape, including the subject-specific HRFs in the GLM allows for a significant improvement in the detection sensitivity of aPFC pain response. This study supports the potential application of individualized analysis in using fNIRS and provides a robust model to perform objective determination of pain perception.
关键词： test–retest reliability,detection sensitivity,hemodynamic response function,anterior prefrontal cortex,pain,near-infrared spectroscopy
更新于2025-09-10 09:29:36
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Near-infrared spectroscopy monitoring during out-of-hospital cardiac arrest: can the initial cerebral tissue oxygenation index predict ROSC?
摘要： study objectives Near-infrared spectroscopy is a modality that can monitor tissue oxygenation index (TOI) and has potential to evaluate return of spontaneous circulation (ROSC) during cardiopulmonary resuscitation (CPR). This study’s objectives were to evaluate whether TOI could be associated with ROSC and used to help guide the decision to either terminate CPR or proceed to extracorporeal CPR (ECPR). Methods In this observational study, we assessed the patients with out-of-hospital cardiac arrest with non-traumatic cause receiving CPR on arrival at our ED between 2013 and 2016. TOI monitoring was discontinued either on CPR termination after ROSC was reached or on patient death. Patients were classified into two groups: ROSC and non-ROSC group. results Out of 141 patients, 24 were excluded and the remaining 117 were classified as follows: ROSC group (n=44) and non-ROSC group (n=73). ROSC group was significantly younger and more likely to have their event witnessed and bystander CPR. ROSC group showed a higher initial TOI than non-ROSC group (60.5%±17.0% vs 37.9%±13.7%: p<0.01). Area under the curve analysis was more accurate with the initial TOI than without it for predicting ROSC (0.88, 95% CI 0.82 to 0.95 vs 0.79, 95% CI 0.70 to 0.87: p<0.01). TOI cut-off value ≥59% appeared to favour survival to hospital discharge whereas TOI ≤24% was associated with non-ROSC. Conclusions This study demonstrated an association between higher initial TOI and ROSC. Initial TOI could increase the accuracy of ROSC prognosis and may be a clinical factor in the decision to terminate CPR and select patients who are to proceed to ECPR.
关键词： tissue oxygenation index,Near-infrared spectroscopy,extracorporeal CPR,cardiopulmonary resuscitation,return of spontaneous circulation
更新于2025-09-10 09:29:36
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[IEEE 2018 37th Chinese Control Conference (CCC) - Wuhan (2018.7.25-2018.7.27)] 2018 37th Chinese Control Conference (CCC) - Near-Infrared Spectrum of Coal Origin Identification Based on SVM Algorithm
摘要： Near infrared spectroscopy is introduced to analyze 243 coal samples of different origins of Australia, Canada, China, Indonesia and Russia, combined with the supportive vector machines (SVM) analysis method. With the pre-processed data from the Principal component analysis (PCA), six supportive vector machines with different kernel functions are employed to discriminate origins of coal samples, namely Linear SVM, Quadratic SVM, Cubic SVM, Fine Gaussian SVM, Medium Gaussian SVM and Coarse Gaussian SVM. Through comparison, Linear SVM has the best performance in prediction accuracy rate while better results are obtained using Medium Gaussian SVM taking accuracy rate and training time into account. It turns out that NIR spectroscopy combined with Medium Gaussian SVM can be used as a good non-destructive method to predict origins of coal, with an accuracy rate of 98.8%, which strengthens the supervision of coal quality.
关键词： Principal component analysis,K- fold cross validation,Supportive vector machines,Near infrared spectroscopy
更新于2025-09-10 09:29:36
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Implementing a method based on near infrared spectroscopy for the “in-situ” determination of ammonia/water composition in an absorber test bench
摘要： This study presents the first results of composition measurement in an ammonia/water mixture determined at real time using near-infrared (NIR) spectroscopy in an absorber test bench. Two cells were designed and constructed; a static cell for calibrating and a dynamic cell for measuring in the absorber test bench. The ammonia absorption band was not significantly affected by the solution flow rate and neither by small variations in the temperature and pressure. A linear regression model between the absorbance value at 1033 nm and the ammonia concentration was established. This model was used to estimate the concentration in an ammonia/water absorber test bench. The methodology was validated by density measurements of the samples. The value of the mean deviation was 0.0024.
关键词： ammonia/water composition,near-infrared spectroscopy,absorber test bench,real-time measurement
更新于2025-09-10 09:29:36
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[IEEE 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Honolulu, HI, USA (2018.7.18-2018.7.21)] 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Near-Infrared Spectroscopy studies on TBI patients with Modified Multiscale Entropy analysis
摘要： Functional near-infrared spectroscopy (fNIRS) is an emerging non-invasive functional brain imaging technique, through detecting the changes of hemoglobin concentrations to investigate brain activities in various tasks. The aim of this study is to investigate the complexity of near-infrared spectroscopy signals during resting state and upper limb movements. Experimental study was designed by applying NIRS to collect the data especially for both healthy subjects and traumatic brain injury (TBI) patients. The modified multiscale entropy (MMSE) algorithm was employed to assess the complexity of fNIRS signals which may reflect the changes of brain activity when people underwent brain injury. The results that the mean MMSE of oxyhemoglobin values was lower in TBI patients compared to healthy subjects, indicated that MMSE was feasible to measure complexity of cerebral near-infrared spectroscopy signals in TBI patients, and that brain injury was associated with the decreased complexity of cerebrovascular reactivity. Moreover, measurement of complexity of brain signals has potential to provide significant guidance for rehabilitation.
关键词： cerebrovascular reactivity,modified multiscale entropy (MMSE),traumatic brain injury (TBI),brain activity,Functional near-infrared spectroscopy (fNIRS)
更新于2025-09-10 09:29:36
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EXPRESS: Bulk Protein and Oil Prediction in Soybean Using Transmission Raman Spectroscopy: A Comparison of Approaches to Optimize Accuracy
摘要： Rapid measurements of protein and oil content are important for a variety of uses, from sorting of soybeans at the point of harvest to feedback during soybean meal production. In this study, our goal is to develop a simple protocol to permit rapid and robust quantitative prediction of soybean constituents using transmission Raman spectroscopy (TRS). To develop this approach, we systematically varied the various elements of the measurement process to provide a diverse test bed. First, we utilized an in-house-built benchtop TRS instrument such that suitable optical configurations could be rapidly deployed and analyzed for experimental data collection for individual soybean grains. Second, we also utilized three different soybean varieties with relatively low (33.97%), medium (36.98%), and high protein (41.23%) contents to test the development process. Third, samples from each variety were prepared using whole bean and three different sample treatments (i.e., ground bean, whole meal, and ground meal). In each case, we modeled the data obtained using partial least squares (PLS) regression and assessed spectral metric-based multiple linear regression (metric-MLR) approaches to build robust prediction models. The metric-MLR models showed lower root mean square errors (RMSEPs), and hence better prediction, compared to corresponding classical PLS regression models for both bulk protein and oil for all treatment types. Comparing different sample preparation approaches, a lower RMSEPs was observed for whole meal treatment and thus the metric-MLR modeling with ground meal treatment was considered to be optimal protocol for bulk protein and oil prediction in soybean, with RMSEP values of 1.15±0.04 (R2= 0.87) and 0.80±0.02 (R2= 0.87) for bulk protein and oil, respectively. These predictions were nearly two- to three-fold better (i.e., lower RMSEPs) than the corresponding NIR spectroscopy measurements (i.e., secondary gold standards in grain industry). For content prediction in whole soybean, incorporating physical attributes of individual grains in metric-MLR approach show up to 22% improvement in bulk protein and a relatively mild (up to ~ 5%) improvement in bulk oil prediction. The unique combination of metric-MLR modeling approach (which is rare in the field of grain analysis) and sample treatments resulted in improved prediction models, and using the physical attributes of individual grains is suggested as a novel measure for improving accuracy in prediction.
关键词： near-infrared spectroscopy,Soybean,NIR spectroscopy,MLR,transmission Raman spectroscopy,multiple liner regression,PLS regression
更新于2025-09-09 09:28:46
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Infrared Investigations of the Neutral-Ionic Phase Transition in TTF-CA and Its Dynamics
摘要： The neutral-ionic phase transition in TTF-CA was investigated by steady-state and time-resolved infrared spectroscopy. We describe the growth of high-quality single crystals and their characterization. Extended theoretical calculations were performed in order to obtain the band structure, the molecular vibrational modes and the optical spectra along all crystallographic axes. The theoretical results are compared to polarization-dependent infrared reflection experiments. The temperature-dependent optical conductivity is discussed in detail. We study the photo-induced phase transition in the vicinity of thermally-induced neutral-ionic transition. The observed temporal dynamics of the photo-induced states is attributed to the random-walk of neutral-ionic domain walls. We simulate the random-walk annihilation process of domain walls on a one-dimensional chain.
关键词： domain-wall motion,neutral-ionic phase transition,steady-state and transient infrared spectroscopy,TTF-CA,charge-transfer salts,characterization,random-walk simulations,light-induced phase transition,vibrational spectroscopy,crystal growth
更新于2025-09-09 09:28:46
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Chemical analysis of in vivo–irradiated dentine of head and neck cancer patients by ATR-FTIR and Raman spectroscopy
摘要： Objectives To evaluate the effect of in vivo radiotherapy on the chemical properties of human dentine by Fourier-transform infrared spectroscopy (FTIR) and Raman analysis. Materials and methods Chemical composition was evaluated comparing control and irradiated group (n = 8). Irradiated teeth were obtained from radiotherapy patients subjected to fractionated X-ray radiation of 1.8 Gy daily totaling 72 Gy. The teeth were sectioned according to the type of dentine (crown or root dentine), obtaining 3-mm dentine cervical slices. The analyzed parameters by FTIR and Raman spectroscopies were mineral/matrix ratio (M:M), carbonate/mineral ratio (C:M), amide I/amide III ratio, and amide I/CH2 ratio. Raman also calculated the phosphate and carbonate crystallinity. Results FTIR revealed that M:M had a decrease in both factors (p = 0.008; p = 0.043, respectively) and root dentine showed a lower C:M in the irradiated group (p = 0.003). Raman revealed a higher phosphate crystallinity and a lower carbonate crystallinity in crown dentine of irradiated group (p = 0.021; p = 0.039). For amide I/amide III, the irradiated showed a lower ratio when compared to the control group (FTIR p = 0.002; Raman p = 0.017). For amide I/CH2, the root dentine showed a higher ratio than the crown dentine in both methods (p < 0.001). Conclusions Radiotherapy altered the chemical composition of human dentine. The exchange of phosphate-carbonate ions in the hydroxyapatite and higher concentration of organic components was found after radiotherapy. Clinical relevance The increased risk of radiation-related caries in patients undergoing head and neck radiotherapy is due not only to salivary, dietary, and microbiological changes but also to changes in tooth chemical composition.
关键词： Radiotherapy,Raman spectroscopy,Head and neck cancer,Fourier-transform infrared spectroscopy,Dentine
更新于2025-09-09 09:28:46
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Raman and infrared spectroscopy reveal that proliferating and quiescent human fibroblast cells age by biochemically similar but not identical processes
摘要： Dermal fibroblast cells can adopt different cell states such as proliferation, quiescence, apoptosis or senescence, in order to ensure tissue homeostasis. Proliferating (dividing) cells pass through the phases of the cell cycle, while quiescent and senescent cells exist in a non-proliferating cell cycle-arrested state. However, the reversible quiescence state is in contrast to the irreversible senescence state. Long-term quiescent cells transit into senescence indicating that cells age also when not passing through the cell cycle. Here, by label-free in vitro vibrational spectroscopy, we studied the biomolecular composition of quiescent dermal fibroblast cells and compared them with those of proliferating and senescent cells. Spectra were examined by multivariate statistical analysis using a PLS-LDA classification model, revealing differences in the biomolecular composition between the cell states mainly associated with protein alterations (variations in the side chain residues of amino acids and protein secondary structure), but also within nucleic acids and lipids. We observed spectral changes in quiescent compared to proliferating cells, which increased with quiescence cultivation time. Raman and infrared spectroscopy, which yield complementary biochemical information, clearly distinguished contact-inhibited from serum-starved quiescent cells. Furthermore, the spectra displayed spectral differences between quiescent cells and proliferating cells, which had recovered from quiescence. This became more distinct with increasing quiescence cultivation time. When comparing proliferating, (in particular long-term) quiescent and senescent cells, we found that Raman as well as infrared spectroscopy can separate these three cellular states from each other due to differences in their biomolecular composition. Our spectroscopic analysis shows that proliferating and quiescent fibroblast cells age by similar but biochemically not identical processes. Despite their aging induced changes, over long time periods quiescent cells can return into the cell cycle. Finally however, the cell cycle arrest becomes irreversible indicating senescence.
关键词： PLS-LDA classification model,Raman spectroscopy,infrared spectroscopy,quiescence,senescence,proliferation,fibroblast cells,biomolecular composition
更新于2025-09-09 09:28:46
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First vibrational investigations of N <sub/>2</sub> O–H <sub/>2</sub> O, N <sub/>2</sub> O–(H <sub/>2</sub> O) <sub/>2</sub> , and (N <sub/>2</sub> O) <sub/>2</sub> –H <sub/>2</sub> O complexes from the far to the near-infrared spectral region by neon matrix isolation and <i>ab initio</i> calculations
摘要： We present for the first time the investigation of water molecules complexed with dinitrogen monoxide, two abundant molecules in atmosphere, in solid neon using Fourier transform infrared (IR) spectroscopy. We identify at least three complexes from concentration effects, N2O–H2O, N2O–(H2O)2, and (N2O)2–H2O, by observation of new absorption bands close to the monomer fundamental modes from the far to the near IR region. We highlight the presence of isomers for the N2O–H2O complex with the help of theoretical calculations at second order M?ller-Plesset (MP2) and coupled-cluster single double triple-F12a/aug-cc-pVTZ levels. The observed frequencies for the N2O–(H2O)2 and (N2O)2–H2O complexes are compared with MP2/aug-cc-pVTZ harmonic data. Anharmonic coupling constants have been derived from the observations of overtones and combination bands.
关键词： ab initio calculations,anharmonic coupling constants,neon matrix isolation,N2O–H2O complexes,Fourier transform infrared spectroscopy
更新于2025-09-09 09:28:46