Enhancement of optical penetration depth of LED-based NIRS systems by comparing different beam profiles

Mirbagheri, Mahya; Hakimi, Naser; Ebrahimzadeh, Elias; Pourrezaei, Kambiz; Setarehdan, Seyed Kamaledin

doi:10.1088/2057-1976/ab42d9

Cited by 10 publications

(6 citation statements)

References 86 publications

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“…Moreover, other recording techniques are highly affected by movement while fNIRS is less so. As such, fNIRS has been used to delineate the neural mechanisms underlying a range of perceptual and cognitive processes (e.g., Borjkhani and Setarehdan, 2020;Bortfeld et al, 2009Bortfeld et al, , 2007Chen et al, 2011;Mirbagheri et al, 2019;Ebrahimzadeh et al, 2019;Jahani et al, 2015;Mirbagheri et al, 2020;Pollonini et al, 2014;Rahimpour et al, 2017Rahimpour et al, , 2018. Here we extend the findings of Jantzen and colleagues (Jantzen et al, 2004) to fNIRS, with the goal of establishing whether fNIRS is spatially and temporally sensitive enough to differentiate activation in the different cortex-specific regions of interest identified by Jantzen et al to be differentially engaged by synchronized and syncopated finger tapping.…”

Section: Introductionmentioning

confidence: 74%

Tracking differential activation of primary and supplementary motor cortex across timing tasks: An fNIRS validation study

Rahimpour

Pollonini

Comstock

et al. 2020

Journal of Neuroscience Methods

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Functional near-infrared spectroscopy (fNIRS) provides an alternative to functional magnetic resonance imaging (fMRI) for assessing changes in cortical hemodynamics. To establish the utility of fNIRS for measuring differential recruitment of the motor network during the production of timing-based actions, we measured cortical hemodynamic responses in 10 healthy adults while they performed two versions of a finger-tapping task. The task, used in an earlier fMRI study (Jantzen et al., 2004), was designed to track the neural basis of different timing behaviors. Participants paced their tapping to a metronomic tone, then continued tapping at the established pace without the tone. Initial tapping was either synchronous or syncopated relative to the tone. This produced a 2 × 2 design: synchronous or syncopated tapping and pacing the tapping with or continuing without a tone. Accuracy of the timing of tapping was tracked while cortical hemodynamics were monitored using fNIRS. Hemodynamic responses were computed by canonical statistical analysis across trials in each of the four conditions. Task-induced brain activation resulted in significant increases in oxygenated hemoglobin concentration (oxy-Hb) in a broad region in and around the motor cortex. Overall, syncopated tapping was harder behaviorally and produced more cortical activation than synchronous tapping. Thus, we observed significant changes in oxy-Hb in direct relation to the complexity of the task.

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Section: Introductionmentioning

confidence: 74%

Tracking differential activation of primary and supplementary motor cortex across timing tasks: An fNIRS validation study

Rahimpour

Pollonini

Comstock

et al. 2020

Journal of Neuroscience Methods

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“…In order to apply the Gaussian profile distributions into the mentioned scattering medium, two kinds of lenses including BCX and PCX have been used, the explanation details about their main properties have been detailed in literature. 59 The Uniform distribution was made by using a flat lens implemented by nano antennas 60 and adjusted on the LED probe in the manufacturing company. 58 Next, to produce the Gaussian profiles with different focal points, the beam collimated by the flat lens was passed through PCX and BCX lenses individually to converge firstly in the air and then come together more by undergoing the scattering medium with a higher refractive index.…”

Section: Led Beam Designmentioning

confidence: 99%

Simulation and in vivo investigation of light-emitting diode, near infrared Gaussian beam profiles

Mirbagheri

Hakimi

Ebrahimzadeh

et al. 2019

Journal of Near Infrared Spectroscopy

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Near infrared spectroscopy is an optical imaging technique which offers a non-invasive, portable, and low-cost method for continuously measuring the oxygenation of tissues. In particular, it can provide the brain activation through measuring the blood oxygenation and blood volume in the cortex. Understanding and then improving the spatial and depth sensitivity of near infrared spectroscopy measurements to brain tissue are essential for designing experiments as well as interpreting research findings. In this study, we investigate the effect of applying two common light beam profiles including Uniform and Gaussian on the penetration depth of an LED-based near infrared spectroscopy. In this regard, two Gaussian profiles were produced by adjusting plano-convex and bi-convex lenses and the Uniform profile was provided by applying a flat lens. Two experiments were conducted in this study. First, a simulation experiment was carried out based on scanning the intra space of a liquid phantom by using static and pulsating absorbers to compare the penetration depth of the configurations applied on the LED-based near infrared spectroscopy with that of a laser-based near infrared spectroscopy. Second, to show the feasibility of the best proposed configuration applied, an in vivo experiment of stress assessment has been performed and its results have been compared with that results obtained by laser one. The results showed that the LED-based near infrared spectroscopy equipped with bi-convex lens provides a penetration depth and hence quality measurements of near infrared spectroscopy and its extracted heart rate variability signals as well as laser-based near infrared spectroscopy especially in the application of stress assessment.

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“…It provides a multiparametric evaluation of the brain tissue with respect to both its structural and functional properties. In this context, similar to EEG but at different temporal scales (milliseconds vs. seconds), functional Near Infrared Spectroscopy (fNIRS) ( Mirbagheri et al, 2019 , 2020a , 2020b ) measures the hemodynamic response, that is the change of oxygen in the blood when a brain region becomes active and functional MRI (fMRI) ( Ebrahimzadeh et al, 2019 , 2019a ; Sadjadi et al, 2022 ) offers the possibility for examining the brain functional activation non-invasively both during resting state and task execution, expanding the panel of parameters obtainable by MRI [e.g., structural connectivity evaluated by diffusion tensor imaging (DTI), metabolites concentrations evaluated by magnetic resonance spectroscopy (MRS), and perfusion valuated by arterial spin labeling (ASL)] ( Mele et al, 2019 ). This complementarity of information is highlighted in multimodal recording methods that are designed to overcome the single modality shortcomings and to enhance the patient’s treatment experience.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous electroencephalography-functional magnetic resonance imaging for assessment of human brain function

Ebrahimzadeh

Saharkhiz

Rajabion

et al. 2022

Front. Syst. Neurosci.

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Electroencephalography (EEG) and functional Magnetic Resonance Imaging (MRI) have long been used as tools to examine brain activity. Since both methods are very sensitive to changes of synaptic activity, simultaneous recording of EEG and fMRI can provide both high temporal and spatial resolution. Therefore, the two modalities are now integrated into a hybrid tool, EEG-fMRI, which encapsulates the useful properties of the two. Among other benefits, EEG-fMRI can contribute to a better understanding of brain connectivity and networks. This review lays its focus on the methodologies applied in performing EEG-fMRI studies, namely techniques used for the recording of EEG inside the scanner, artifact removal, and statistical analysis of the fMRI signal. We will investigate simultaneous resting-state and task-based EEG-fMRI studies and discuss their clinical and technological perspectives. Moreover, it is established that the brain regions affected by a task-based neural activity might not be limited to the regions in which they have been initiated. Advanced methods can help reveal the regions responsible for or affected by a developed neural network. Therefore, we have also looked into studies related to characterization of structure and dynamics of brain networks. The reviewed literature suggests that EEG-fMRI can provide valuable complementary information about brain neural networks and functions.

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Enhancement of optical penetration depth of LED-based NIRS systems by comparing different beam profiles

Cited by 10 publications

References 86 publications

Tracking differential activation of primary and supplementary motor cortex across timing tasks: An fNIRS validation study

Tracking differential activation of primary and supplementary motor cortex across timing tasks: An fNIRS validation study

Simulation and in vivo investigation of light-emitting diode, near infrared Gaussian beam profiles

Simultaneous electroencephalography-functional magnetic resonance imaging for assessment of human brain function

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