Towards the next generation of near-infrared spectroscopy

Hoshi, Yoko

doi:10.1098/rsta.2011.0262

Cited by 60 publications

(51 citation statements)

References 85 publications

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“…In the case of a homogeneous semi-infinite medium, explicit analytical formation of the DPF was given by reports including Fantini et al 9 and Boas et al 10 A semi-infinite geometry is a reasonable representation of the measurement geometry for a set of optodes separated by a few centimeters when externally placed on large tissue areas. However, in cases involving measurement of the brain, different head sizes (infant to adult), different global shapes of the head (Caucasian to Asian), different regions of the head 11 (e.g., prefrontal or parietal), and even different ages 12 may result in different DPFs. Therefore, an analytical form of DPF that indicates the effect of the size and shape of the nonsemi-infinite geometry, even at the simplest case of a homogeneous medium that is the basis for analysis of more realistic geometries, may be informative for the development of better strategies to the quantitation of the chromophore changes when the wavelength dependency of DPF is also taken into account.…”

Section: Introductionmentioning

confidence: 99%

On the geometry dependence of differential pathlength factor for near-infrared spectroscopy. I. Steady-state with homogeneous medium

Piao

Barbour

Graber³

et al. 2015

J. Biomed. Opt

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Abstract. This work analytically examines some dependences of the differential pathlength factor (DPF) for steady-state photon diffusion in a homogeneous medium on the shape, dimension, and absorption and reduced scattering coefficients of the medium. The medium geometries considered include a semi-infinite geometry, an infinite-length cylinder evaluated along the azimuthal direction, and a sphere. Steady-state photon fluence rate in the cylinder and sphere geometries is represented by a form involving the physical source, its image with respect to the associated extrapolated half-plane, and a radius-dependent term, leading to simplified formula for estimating the DPFs. With the source-detector distance and medium optical properties held fixed across all three geometries, and equal radii for the cylinder and sphere, the DPF is the greatest in the semi-infinite and the smallest in the sphere geometry. When compared to the results from finite-element method, the DPFs analytically estimated for 10 to 25 mm source-detector separations on a sphere of 50 mm radius with μ a ¼ 0.01 mm −1 and μ 0 s ¼ 1.0 mm −1 are on average less than 5% different. The approximation for sphere, generally valid for a diameter ≥20 times of the effective attenuation pathlength, may be useful for rapid estimation of DPFs in near-infrared spectroscopy of an infant head and for short source-detector separation. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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Section: Introductionmentioning

confidence: 99%

On the geometry dependence of differential pathlength factor for near-infrared spectroscopy. I. Steady-state with homogeneous medium

Piao

Barbour

Graber³

et al. 2015

J. Biomed. Opt

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“…Furthermore, NIRS is not restrictive and has the advantage of allowing a real-time measurement when asking the subject to perform a task [17] [18].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Expression Recognition Function in Autism Spectrum Disorder Using Near-Infrared Spectroscopy

Furukawa¹,

Mori²,

Mori³

et al. 2018

OJPsych

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One of the characteristics of Autism Spectrum Disorder (ASD) is social disorder. The specificity of facial and expression recognition for people with ASD is gathering attention as a factor of this social disorder. The study examined the hemodynamic activities in the prefrontal cortex using near-infrared spectroscopy (NIRS) when a person with ASD performed an expression recognition task. The subjects were twenty males (18 -22 years old) with ASD and without intellectual disabilities. Forty-five healthy males matched for age and sex were included as a control group. In both groups, the degree of autistic tendencies was evaluated using the Autism-Spectrum Quotient (AQ). Using eight standard emotional expressions of Japanese people, two expression recognition tasks were set. An NIRS was used to measure the prefrontal cortex blood mobilization during the expression-processing process. The AQ was significantly higher in the ASD group, while the rate of overall correct expression response was significantly lower (p < 0.001). A negative correlation was found when the relationship between the AQ and the rate of overall correct expression response was evaluated by combining the results of the control group with those of the ASD group (ρ = −0.40 p < 0.001). In the automatic expression-processing task, no activation in the prefrontal cortex was found in either the ASD or the control group. In the conscious expression-processing task, the activation of the left and right lateral prefrontal cortex was weaker in the ASD group compared to the control group. Unlike in the control group, a mild activation of posterior prefrontal cortex was found in the ASD group. The expression-processing process of the ASD group was found to be different from that of the control group. NIRS was effective in detecting a brain function disorder in people with ASD during an expression-processing process.

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“…Using finite element simulation methods, the depth of recorded neural activation can be computed from the absorption variations [5]. Thus, localized cortical activity can be deduced from the hemodynamic profile in real time [1][2][3], but it is often assumed that oxygen delivery and oxygen extraction are coupled and co-varied together. This study will verify whether such oxy-and deoxy-Hb hemodynamic profiles are coupled or decoupled temporally during a cognitive motor task.…”

Section: Introductionmentioning

confidence: 99%

“…In contrast, fMRI detects only deoxygenation in the venous return. Functional NIRS can detect high-resolution temporal signals in msec [1][2][3] providing real-time monitoring of changes in hemodynamic responses, whereas fMRI usually acquires low-resolution temporal signals when it takes 1 sec to scan the whole brain.…”

Section: Introductionmentioning

confidence: 99%

“…fNIRS has been used as a noninvasive optical imaging technique to detect neural activation according to the hemodynamic response of the imaged neural tissues [1][2][3][4]. Hemoglobin molecules is known to absorb light in the near-infrared (NIR) spectral region, with a characteristic different absorption spectra for oxy-Hb (HbO 2 ) and deoxy-Hb (Hb) based on the molecular chemical bonds [4].…”

Section: Introductionmentioning

confidence: 99%

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Temporal decoupling of oxy- and deoxy-hemoglobin hemodynamic responses detected by functional near-infrared spectroscopy (fNIRS)

Tam

Zouridakis

2014

JBEMi

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This study provides experimental evidence that there is temporal decoupling between the hemodynamic responses of oxy-and deoxy-hemoglobin (Hb) as detected by functional nearinfrared spectroscopy (fNIRS). Using 64 spatially distributed optrodes to record motor cortical activities during a free arm movement task (right-left and front-back movements), we detected that the temporal profile of oxy-and deoxy-Hb responses are desynchronized and decoupled (i.e., oxy-and deoxy-Hb levels do not rise and fall at the same time). We correlated four different measures of hemodynamic profiles with the arm movements, namely, oxy-(HbO 2 ) and deoxy-hemoglobin (Hb) and their summation (HbO 2 + Hb) and difference (HbO 2 -Hb) signals. These measures correspond to the changes in oxygen delivery, oxygen extraction, total blood volume delivered, and total oxygenation with specific movement directions, respectively. They revealed different components of the hemodynamic response in a localized neuronal population in the motor cortex. The results suggested that, by using these four measures, oxygen delivery and oxygen extraction can be coupled in one movement direction, but decoupled in another movement direction for the same human subject executing the same movement task. Oxygen delivery and oxygen extraction do not always co-vary together temporally. Thus, using a single measure of oxygen delivery or extraction alone may not be sufficient to determine whether the cortical area is activated or deactivated. Rather, a combination of all four measures of hemodynamic signals that represent temporal coupling and decoupling of oxygen delivery and extraction is needed to differentiate the temporal profiles of neural activation and deactivation. It demonstrated that different hemodynamic measures can reveal temporally decoupled activation/deactivation patterns differentially during the right-left and front-back motor task. Therefore, relying on a single measure of deoxy-Hb may be insufficient to characterize the neural responses without the oxy-Hb measure. Orthogonal arm

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Towards the next generation of near-infrared spectroscopy

Cited by 60 publications

References 85 publications

On the geometry dependence of differential pathlength factor for near-infrared spectroscopy. I. Steady-state with homogeneous medium

On the geometry dependence of differential pathlength factor for near-infrared spectroscopy. I. Steady-state with homogeneous medium

Evaluation of Expression Recognition Function in Autism Spectrum Disorder Using Near-Infrared Spectroscopy

Temporal decoupling of oxy- and deoxy-hemoglobin hemodynamic responses detected by functional near-infrared spectroscopy (fNIRS)

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