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- 摘要
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- 实验方案
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Revolutionizing Tropical Medicine (Point-of-Care Tests, New Imaging Technologies and Digital Health) || The Use of Near-Infrared Spectroscopy to Monitor Tissue Oxygenation, Metabolism and Injury in Low Resource Settings
摘要： In a low resource setting there are many barriers for providing the standard of healthcare that is normal in developed countries. Modern healthcare largely depends on reliable and accurate medical devices that can diagnose disease, monitor treatment and provide accurate prognostic information. Often medical devices are associated with high costs for purchasing and maintenance that often includes costs for a large number of consumables. In addition, a particular infrastructure is required and highly trained staff are needed to operate these devices. To be successful and useful in low‐ and middle‐income countries (LMICs), a medical device needs to be inexpensive, portable, safe, non‐invasive, easy to use and interpret, and battery‐powered. Near‐infrared spectroscopy (NIRS) is a medical device that fulfills all of these requirements and thus has great potential to make an impact on healthcare in LMICs. Its most important use to date has been in neurological monitoring. Its success in this field is due to its low cost, ease of use and ability to be used in a low resource environment.
关键词： metabolism,Near‐Infrared Spectroscopy,NIRS,tissue oxygenation,injury,low resource settings
更新于2025-09-11 14:15:04
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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) - An Ultra-miniaturized Near Infrared Spectroscopy System to Assess Sleep Apnea in Children with Down Syndrome
摘要： Down syndrome is one of the health disorders that interferes with regular and healthy sleep. Most children with Down syndrome are referred to a sleep clinic for the assessment of the severity of their apnea. Regular polysomnography based assessment of apnea has been challenging with this sensitive patient population. We present our efforts towards developing a flexible adhesive bandage sized near infrared spectroscopy system (pediBand) for home-assessment of apnea in children with Down syndrome. Combined with inertial measurement units, pediBand record heart rate, heart rate variability, respiratory rate, arterial oxygen saturation and cerebral oxygen saturation. These are the essential parameters to assess sleep apnea and could also potentially be used in the assessment of sleep performance in general. A modified version of pediBand system was evaluated on adult patients and successfully demonstrated the changes in hemodynamic system triggered by sleep apnea.
关键词： polysomnography,sleep,inertial measurement units,Down syndrome,Near infrared spectroscopy
更新于2025-09-11 14:15:04
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Principle of pulse oximetry
摘要： In the ICU, electrocardiogram (ECG) and SpO2 are required for patient monitoring. An ECG shows cardiac electrical activity, but pulse oximetry can measure the pulse rate and SpO2 using plethysmogram. Arterial blood drawing is not needed, and the SpO2 measurements are noninvasive, unlike SaO2 measurements. SpO2 is measured using a red light, an infrared light, and absorption spectroscopy. There are many factors affecting the measurement of SpO2. A low peripheral circulation and body movement can make the detection of the pulse wave difficult, greatly decreasing the accuracy of the SpO2 measurement. The solution for this disturbance to the measurement varies according to each maker. Understanding the principle of measurement is necessary for the interpretation of SpO2 values. There are two methods for measuring SpO2: transmittance and reflectance. The reflection type measures SpO2 at the supra-orbital artery, wherein arterial heartbeat is maintained at the time of a shock and the hypothermia. Moreover, the reflection type has a shorter discrimination time to SpO2 change than the finger of limb. This method is suitable for ICU patients with low peripheral perfusion and motion artifacts.
关键词： plethysmogram,absorption spectroscopy,SpO2,near-infrared spectroscopy,pulse oximeter
更新于2025-09-10 09:29:36
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Spontaneous Low Frequency Oscillations in Acute Ischemic Stroke ? A Near Infrared Spectroscopy (NIRS) Study
摘要： Background and purpose: Continuous wave near infrared spectroscopy (NIRS) is a non-invasive bed-side optical method to detect changes in oxygenated (oxyHb) and deoxygenated hemoglobin (deoxyHb) in the outermost layers of the cerebral cortex. Cortical oxyHb low frequency oscillations (LFOs) in the 0.09-0.11 Hz range are affected by changes in cerebral autoregulation (CA), which is altered following stroke. We examined oxyHb LFOs at bed-side as a marker of CA in the subacute phase in stroke patients with or without recombinant tissue plasminogen activator thrombolytic therapy. Methods: We recruited 29 patients admitted to the stroke unit with symptoms of ischemic stroke. 11/29 patients received thrombolytic therapy. NIRS examination was conducted 2 days (median time) from stroke onset. NIRS optodes were placed on each side of the head with a 3 cm source-detector distance. Using transfer function analysis, inter-hemispheric phase shift and amplitude ratio of the oxyHb oscillations in the 0.09-0.11 Hz range were assessed. Results: The correlation between NIHSS scores at admission and oxyHb parameters revealed a significant positive correlation between stroke severity at admission and inter-hemispheric phase shift (P=0.028). The oxyHb absolute inter-hemispheric phase shift was significantly less in patients receiving thrombolytic therapy compared to non-thrombolytic therapy patients (3° vs. 23°, P=0.005). Conclusions: Stroke severity correlates with the degree of impaired cortical CA and stroke patients receiving thrombolytic therapy might have less severely impaired CA. NIRS detects alteration in cortical oxyHb LFOs between hemispheres in stroke patients in the subacute phase and may be a feasible method to explore changes at bed-side in a stroke unit.
关键词： Stroke,rtPA thrombolytic therapy,Low frequency oscillations,Transfer function analysis,Cerebral autoregulation,Thrombolytic treatment,Near infrared spectroscopy
更新于2025-09-10 09:29:36
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Feasibility of NIRS-based neurofeedback training in social anxiety disorder: behavioral and neural correlates
摘要： Attention biases towards threat signals have been linked to the etiology and symptomatology of social anxiety disorder (SAD). Dysfunction of the dorsolateral prefrontal cortex (dlPFC) may contribute to attention biases in anxious individuals. The aim of this study was to investigate the feasibility of near-infrared spectroscopy (NIRS) neurofeedback (NF) training—targeting the dlPFC—and its effects on threat-related attention biases of individuals with SAD. 12 individuals with SAD participated in the NIRS-NF training lasting 6–8 weeks and including a total of 15 sessions. NF performance increased significantly, while the attention bias towards threat-related stimuli and SAD symptom severity decreased after the training. The individual increase in neurofeedback performance as well as the individual decrease in SAD symptom severity was correlated with decreased responses to social threat signals in the cerebral attention system. Thus, this pilot study does not only demonstrate that NIRS-based NF is feasible in SAD patients, but also may be a promising method to investigate the causal role of the dlPFC in attention biases in SAD. Its effectiveness as a treatment tool might be examined in future studies.
关键词： Social anxiety disorder,Near-infrared spectroscopy,DlPFC,Laughter,Attention bias
更新于2025-09-10 09:29:36
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Removing Task-Induced Superficial-Tissue Hemodynamics and Head Motion-Induced Artifacts in Functional Near-Infrared Spectroscopy
摘要： Functional near-infrared spectroscopy, a neuroimaging tool used to measure brain activity, is associated with two different types of artifacts: (a) task-induced super?cial-tissue hemodynamic artifacts derived from the scalp; and (b) motion artifacts caused by head motions. Recently, a simple and easy-to-use method, based on a general linear model incorporating super?cial hemodynamics model estimated from short-probe distance channels using principal component analysis, was proposed to remove task-induced super?cial-tissue artifacts. In the present study, we examined the effectiveness of this method in removing task-induced and head motion-induced super?cial-tissue hemodynamics. Thus, we conducted a motor experiment where participants were asked to perform grasping movements. During some sessions, head motions were generated in order to introduce motion artifacts. Although the removal of motion artifacts was not perfect, we found that analyses including the ?rst and second principal component (estimated from short-channels) showed a tendency to provide accurate detection of brain activity. This ?nding demonstrated the possibility of conducting effective analysis of functional near-infrared spectroscopy using general linear model and short-channels.
关键词： motion artifact removals,general linear model,functional near-infrared spectroscopy
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) - A Modified Common Spatial Pattern Algorithm Customized for Feature Dimensionality Reduction in fNIRS-Based BCIs
摘要： Functional near-infrared spectroscopy (fNIRS) is a non-invasive multi-channel imaging tool for assessing brain activities, which has shown its high potential in brain-computer interface (BCI) technique. Most previous studies have focused on constructing high dimensional features from whole channels, adding to the complexity of their classifiers. Another multi-channel source for BCI is electroencephalograph (EEG), which possesses different spatial and temporal features from fNIRS. In EEG field, Common Spatial Pattern (CSP) algorithm is widely used aimed at dimensionality reduction. In our article, we modified it based on the characteristics of fNIRS and evaluated its effectiveness in discriminating Mental Arithmetic (MA) against resting status in an open-access dataset. The Modified Common Spatial Pattern algorithm significantly outperforms CSP algorithm in fNIRS-based BCI and shows its potential in further BCI related explorations.
关键词： Common Spatial Pattern (CSP),Mental Arithmetic (MA),Modified Common Spatial Pattern (MCSP),brain-computer interface (BCI),Functional near-infrared spectroscopy (fNIRS)
更新于2025-09-10 09:29:36
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Nondestructive Determination of the Compressive Strength of Wood Using Near-Infrared Spectroscopy
摘要： In this study, Xylosma racemosum was selected as the raw material and its compressive strength was predicted through nondestructive methods. The test data consisted of 160 near-infrared (NIR) absorption spectra of the wood samples obtained using an NIR spectrometer, with the wavelength range of 900 to 1900 nm. The original absorption spectra were pre-processed with multiplicative scatter correction (MSC) and Savitzky-Golay (SG) smoothing and divided into several intervals using the backward interval partial least squares (BiPLS) method. The optimal combination of intervals with the smallest root mean square error of cross validation (RMSECV) value was selected, and a genetic algorithm (GA) was used to select featured wavelengths. Finally, a partial least squares (PLS) regression model was established with the featured wavelengths. The BiPLS-GA-PLS model outperformed the other models, resulting in a high prediction correlation coefficient of 0.927 and a root mean square error rate of 4.06. Based on the results, it is feasible to accurately measure the compressive strength of wood processed by different methods using near-infrared spectroscopy.
关键词： Prediction,BiPLS-GA,Compressive strength,Near-infrared spectroscopy
更新于2025-09-10 09:29:36
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Comparative Quantification of Arterial Lipid by Intravascular Photoacoustic-Ultrasound Imaging and Near-Infrared Spectroscopy-Intravascular Ultrasound
摘要： Intravascular photoacoustic-ultrasound (IVPA-US) imaging and near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS) are two hybrid modalities that detect arterial lipid, with comparison necessary to understand the relative advantages of each. We performed in vivo and ex vivo IVPA-US imaging of the iliac arteries of Ossabaw swine with metabolic syndrome (MetS) and lean swine to investigate sensitivity for early-stage atherosclerosis. We repeated imaging ex vivo with NIRS-IVUS for comparison to IVPA-US and histology. Both modalities showed significantly greater lipid in MetS vs. lean swine, but only IVPA-US localized the lipid as perivascular. To investigate late-stage atherosclerosis, we performed ex vivo IVPA-US imaging of a human coronary artery with comparison to NIRS-IVUS and histology. Two advanced fibroatheromas were identified, with agreement between IVPA-measured lipid area and NIRS-derived lipid content. As confirmed histologically, IVPA-US has sensitivity to detect lipid content similar to NIRS-IVUS and provides additional depth resolution, enabling quantification and localization of lipid cores within plaques.
关键词： Swine,Lipid core plaque,Near-infrared spectroscopy,Human,Intravascular imaging,Photoacoustic imaging,Atherosclerosis,Perivascular adipose tissue
更新于2025-09-10 09:29:36
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Neuroergonomics || Functional Near-Infrared Spectroscopy
摘要： The mission of social psychology is to understand “how the thoughts, feelings, and behaviour of individuals are influenced by the actual, imagined, or implied presence of others.” The mission of social neuroscience is to understand the neural and broader biological underpinnings of social psychological phenomena. Like every scientific discipline, the success of social neuroscience rests on the effectiveness of its methods. Recent years have witnessed a proliferation of methods that hold promise for advancing social neuroscience. One such method is continuous-wave functional near-infrared spectroscopy (fNIRS), a functional neuroimaging technique that can be used to measure brain activity noninvasively. In this chapter we demonstrate the utility of fNIRS for social neuroscience in identifying well-established patterns of prefrontal activity when people make self- and other-referential judgments.
关键词： social neuroscience,self-referential judgments,prefrontal activity,functional near-infrared spectroscopy,fNIRS
更新于2025-09-10 09:29:36