Decreased cerebral haemodynamic response to cognitive and physiological tasks in mood disorders as shown by near-infrared spectroscopy

2002 ◽  
Vol 32 (6) ◽  
pp. 1029-1037 ◽  
Author(s):  
K. MATSUO, ◽  
N. KATO ◽  
T. KATO

Background. Hypofrontality has been demonstrated in mood disorders by functional brain imaging methods such as positron emission tomography. However, the neurobiological basis of hypofrontality has not been well clarified. Near-infrared spectroscopy (NIRS) is a non-invasive technique for continuous monitoring of alterations in oxygenated (oxyHb) and deoxygenated (deoxyHb) haemoglobin using near-infrared light, which penetrates biological tissues.Methods. We used NIRS during cognitive and physiological tasks to investigate alterations of haemoglobin oxygenation in the frontal region of euthymic patients with mood disorders (major depressive disorder (MD) and bipolar disorder (BP)) and in controls.Results. The increase of oxyHb during a verbal fluency task was significantly less in the MD and the BP groups than in the controls. The MD group showed a significantly smaller decrease of oxyHb during hyperventilation than the controls. The BP group also showed a similar trend.Conclusions. These findings suggest that the hypofrontality in mood disorders may be associated with a poor response in the cerebral blood vessels to neuronal and chemical stimuli.

2020 ◽  
Vol 10 (3) ◽  
pp. 1068 ◽  
Author(s):  
Giovanni Maira ◽  
Antonio M. Chiarelli ◽  
Stefano Brafa ◽  
Sebania Libertino ◽  
Giorgio Fallica ◽  
...  

We built a fiber-less prototype of an optical system with 156 channels each one consisting of an optode made of a silicon photomultiplier (SiPM) and a pair of light emitting diodes (LEDs) operating at 700 nm and 830 nm. The system uses functional near-infrared spectroscopy (fNIRS) and diffuse optical tomography (DOT) imaging of the cortical activity of the human brain at frequencies above 1 Hz. In this paper, we discuss testing and system optimization performed through measurements on a multi-layered optical phantom with mechanically movable parts that simulate near-infrared light scattering inhomogeneities. The baseline optical characteristics of the phantom are carefully characterized and compared to those of human tissues. Here we discuss several technical aspects of the system development, such as LED light output drift and its possible compensation, SiPM linearity, corrections of channel signal differences, and signal-to-noise ratio (SNR). We implement an imaging algorithm that investigates large phantom regions. Thanks to the use of SiPMs, very large source-to-detector distances are acquired with a high SNR and 2 Hz time resolution. The overall results demonstrate the high potentialities of a system based on SiPMs for fNIRS/DOT human brain imaging applications.


2011 ◽  
Vol 04 (03) ◽  
pp. 251-260 ◽  
Author(s):  
ANNA C. MERZAGORA ◽  
MARIA T. SCHULTHEIS ◽  
BANU ONARAL ◽  
MELTEM IZZETOGLU

A frequent consequence of traumatic brain injury (TBI) is cognitive impairment, which results in significant disruption of an individual's everyday living. To date, most clinical rehabilitation interventions still rely on behavioral observation, with little or no quantitative information about physiological changes produced at the brain level. Functional brain imaging has been extensively used in the study of cognitive impairments following TBI. However, its applications to rehabilitation have been limited. This is due in part to the expensive or invasive nature of these modalities. The objective of this study is to apply functional near-infrared spectroscopy (fNIR) to the assessment of attention impairments following TBI. fNIR provides a localized measure of prefrontal hemodynamic activation, which is susceptible to TBI, and it does so in a noninvasive, affordable and wearable way, thus partially overcoming the limitations of other modalities. Participants included 5 TBI subjects and 11 healthy controls. Brain activation measurements were collected during a target categorization task. Significant differences were found in the hemodynamic response between healthy and TBI subjects. In particular, the elicited responses exhibited reduced amplitude in the TBI group. Overall, the results provide first evidence of the ability of fNIR to reveal differences between TBI and healthy subjects in an attention task. fNIR is therefore a promising neuroimaging technique in the field of neurorehabilitation. The use of fNIR in neurorehabilitation applications would benefit from its noninvasiveness and cost-effectiveness and the neurophysiological information obtained through the evaluation of the hemodynamic activation could provide invaluable information to guide the choice of intervention.


1993 ◽  
Vol 75 (4) ◽  
pp. 1884-1889 ◽  
Author(s):  
A. D. Edwards ◽  
C. Richardson ◽  
P. van der Zee ◽  
C. Elwell ◽  
J. S. Wyatt ◽  
...  

A noninvasive method of measuring hemoglobin flow through an organ by near-infrared spectroscopy (NIRS) is described that allows blood flow to be calculated. The method is derived from the Fick principle and uses a small change in arterial oxyhemoglobin concentration (brought about by a change in the fractional inspired O2 concentration) as an intravascular tracer. Changes in deoxyhemoglobin and oxyhemoglobin concentrations are quantified by monitoring variations in the absorption of near-infrared light in the organ, thus providing a measure of tracer accumulation. The tracer input function is calculated from the change in arterial O2 saturation, measured by pulse oximetry. The method was used to determine hemoglobin flow in the forearms of six healthy young adults on 10 occasions. Forearm hemoglobin flow ranged from 22.5 to 82.6 mumol.l-1.min-1. Calculated forearm blood flow ranged from 1.01 to 4.01 ml.100 g-1.min-1. For comparison, forearm blood flow was measured by venous occlusion plethysmography, and the relation between flow calculated by NIRS (y) and plethysmography (x) was y = 0.93x + 0.30 (r2 = 0.95). The mean difference between the methods was 0.14 ml.100 g-1.min-1. The technique may be widely applicable.


2014 ◽  
Vol 513-517 ◽  
pp. 2706-2709
Author(s):  
Wen Cang Zhao ◽  
Xiao Yu Chi ◽  
Cheng Zhang

The harm of stored product pests are very serious, which caused huge losses to the national economy. It is important to strengthen the research on the insects, for the protection of reservoir storage and quarantine. In the recognition of stored product insects, Some insects have anabiosis, once it is missed, if the external environment is favorable, it will flourish and spread, there will be great harm to the storage of food. This paper briefly introduces the basic principle of the near infrared spectroscopy technology combined with the basic principle of digital image processing and recognition technology. The basic principle of automatic identification technology of dead and live insects, it is based on the difference of absorption and reflection of near-infrared light for the identification of insect pests. This paper presents a new idea of research on near infrared spectroscopy technology and digital image processing technology for automatic identification of direction in the dead and live insects.


2015 ◽  
Vol 1 (1) ◽  
pp. 121-123
Author(s):  
Matthias Lange ◽  
Stephanie Liebold ◽  
Chunyi Kan ◽  
Uta Dahmen

AbstractIn this study we analysed ischemic rat liver lobes with Near Infrared Spectroscopy (NIRS) to evaluate the potential of NIRS as predictor of ischemic reperfusion injury (IRI). We were able to predict duration of ischemia using visible and near infrared light.


2019 ◽  
pp. 346-352 ◽  
Author(s):  
John-Lewis Zaukuu ◽  
Zsanett Bodor ◽  
Flora Vitalis ◽  
Victoria Zsom-Muha ◽  
Zoltan Kovacs

Paprika powder is a spice of culinary importance in many homes but it?s powdered form, has been targeted for fraudulent activities intended at consumer deception. Diverse methods have been used to investigate some of these adulterations but there is no report of paprika adulteration with corn flour, although it remains a suspicion. Technologies such as the near infrared spectroscopy (NIRS) possess non-invasive and rapid advantages that could be explored to monitor this type of adulteration. The study aimed to discriminate and quantify different levels of paprika powder adulterated with corn flour, using NIRS. Two authentic paprika types (DP and SP) were purchased from reputable sources in Hungary and artificially adulterated in the laboratory. Three repeats of each adulteration level (40%, 30%, 25%, 20%, 15%, 10%, 5%, 3%, 1%) were prepared and scanned with the Metri NIRS respectively, then, analysed with chemometrics: Linear discriminant analysis (LDA) and partial least squares regression (PLSR). LDA showed 100% recognition and prediction accuracies respectively when DP and SP were analyzed separately to discriminate different concentrations of paprika adulteration. LDA models with NIRS recognize corn flour adulteration with 95.55% and predict it with 95.02% accuracy irrespective of the paprika type used in this experiment. PLSR prediction of 40%, 30%, 25%, 20%, 15%, 10%, 5%, 3%, 1% corn flour adulteration yielded an R2CV of 0.98 (high accuracy) and a low RMSECV of 1.71 g/100g (low error). Near infrared as a non-invasive technique exhibited good potentials for paprika powder authentication when corn flour is used as an adulterant.


2000 ◽  
Vol 93 (4) ◽  
pp. 947-953 ◽  
Author(s):  
H. Marc Watzman ◽  
C. Dean Kurth ◽  
Lisa M. Montenegro ◽  
Jonathan Rome ◽  
James M. Steven ◽  
...  

Background Cerebral oximetry is a noninvasive bedside technology using near-infrared light to monitor cerebral oxygen saturation (Sco2) in an uncertain mixture of arteries, capillaries, and veins. The present study used frequency domain near-infrared spectroscopy to determine the ratio of arterial and venous blood monitored by cerebral oximetry during normoxia, hypoxia, and hypocapnia. Methods Twenty anesthetized children aged < 8 yr with congenital heart disease of varying arterial oxygen saturation (Sao2) were studied during cardiac catheterization. Sco2, Sao2, and jugular bulb oxygen saturation (Sjo2) were measured by frequency domain near-infrared spectroscopy and blood oximetry at normocapnia room air, normocapnia 100% inspired O2, and hypocapnia room air. Results Among subject conditions, Sao2 ranged from 68% to 100%, Sjo2 from 27% to 96%, and Sco2 from 29% to 92%. Sco2 was significantly related to Sao2 (y = 0. 85 x -17, r = 0.47), Sjo2 (y = 0.77 x +13, r = 0.70), and the combination (Sco2 = 0.46 Sao2 + 0.56 Sjo2 - 17, R = 0.71). The arterial and venous contribution to cerebral oximetry was 16 +/- 21% and 84 +/- 21%, respectively (where Sco2 = alpha Sao2 + beta Sjo2 with alpha and beta being arterial and venous contributions). The contribution was similar among conditions but differed significantly among subjects (range, approximately 40:60 to approximately 0:100, arterial:venous). Conclusions Cerebral oximetry monitors an arterial/venous ratio of 16:84, similar in normoxia, hypoxia, and hypocapnia. Because of biologic variation in cerebral arterial/venous ratios, use of a fixed ratio is not a good method to validate the technology.


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