Reevaluation of near-infrared light propagation in the adult human head: implications for functional near-infrared spectroscopy

2005 ◽  
Vol 10 (6) ◽  
pp. 064032 ◽  
Author(s):  
Yoko Hoshi ◽  
Miho Shimada ◽  
Chie Sato ◽  
Yoshinobu Iguchi
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Light Propagation ◽  
Near Infrared ◽  
Human Head ◽  
Infrared Light ◽  
Functional Near Infrared Spectroscopy ◽  
Near Infrared Light ◽  
Adult Human

scholarly journals Effect of head model on Monte Carlo modeling of spatial sensitivity distribution for functional near-infrared spectroscopy

2015 ◽  
Vol 08 (05) ◽  
pp. 1550024 ◽  
Author(s):  
Ting Li ◽  
Yan Li ◽  
Yunlong Sun ◽  
Meixue Duan ◽  
Liyuan Peng
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Light Propagation ◽  
Near Infrared ◽  
Human Head ◽  
Head Model ◽  
Functional Near Infrared Spectroscopy ◽  
Quantitative Evidence ◽  
Spatial Sensitivity ◽  
Sensitivity Distribution

Modeling Light propagation within human head to deduce spatial sensitivity distribution (SSD) is important for Near-infrared spectroscopy (NIRS)/imaging (NIRI) and diffuse correlation tomography. Lots of head models have been used on this issue, including layered head model, artificial simplified head model, MRI slices described head model, and visible human head model. Hereinto, visible Chinese human (VCH) head model is considered to be a most faithful presentation of anatomical structure, and has been highlighted to be employed in modeling light propagation. However, it is not practical for all researchers to use VCH head models and actually increasing number of people are using magnet resonance imaging (MRI) head models. Here, all the above head models were simulated and compared, and we focused on the effect of using different head models on predictions of SSD. Our results were in line with the previous reports on the effect of cerebral cortex folding geometry. Moreover, the influence on SSD increases with the fidelity of head models. And surprisingly, the SSD percentages in scalp and gray matter (region of interest) in MRI head model were found to be 80% and 125% higher than in VCH head model. MRI head models induced nonignorable discrepancy in SSD estimation when compared with VCH head model. This study, as we believe, is the first to focus on comparison among full serials of head model on estimating SSD, and provided quantitative evidence for MRI head model users to calibrate their SSD estimation.

scholarly journals Shining light on the brain to understand how it works and to help children who face difficulties

2020 ◽  
Author(s):  
Laura Bell ◽  
Vanessa Reindl ◽  
Jana Kruppa ◽  
Alexandra Niephaus ◽  
Simon Huldreich Kohl ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Brain Activation ◽  
Infrared Light ◽  
Functional Near Infrared Spectroscopy ◽  
Near Infrared Light ◽  
Daily Lives ◽  
Total Light ◽  
The Brain

Have you ever thought that light could tell you something about your brain? Light is a powerful tool that helps brain researchers understand the brain. Our eyes can only see less than 1 % of the total light around us. Some of the light is red, so-called near-infrared light. It can run through your head and the top layers of your brain and thereby gains important information about your brain activation. The technique that uses near-infrared light is called functional near-infrared spectroscopy. This term is very long, so we will call it “fNIRS” from now on. In this article, we will first show you how a fNIRS machine looks like and what it is like to take part in a fNIRS experiment. Next, we will explain how we can use near-infrared light to better understand the brain. Finally, we will give you some examples of what fNIRS can be used for and how we can use it to help children who face difficulties in their daily lives.

scholarly journals Imaging System Based on Silicon Photomultipliers and Light Emitting Diodes for Functional Near-Infrared Spectroscopy

2020 ◽  
Vol 10 (3) ◽  
pp. 1068 ◽  
Author(s):  
Giovanni Maira ◽  
Antonio M. Chiarelli ◽  
Stefano Brafa ◽  
Sebania Libertino ◽  
Giorgio Fallica ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Human Brain ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Light Emitting Diodes ◽  
Optical Tomography ◽  
System Optimization ◽  
Infrared Light ◽  
Functional Near Infrared Spectroscopy ◽  
Light Emitting

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.

scholarly journals Shining Light On The Brain to Understand How It Works

2021 ◽  
Vol 9 ◽  
Author(s):  
Laura Bell ◽  
Vanessa Reindl ◽  
Jana A. Kruppa ◽  
Alexandra Niephaus ◽  
Simon H. Kohl ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared ◽  
Brain Activity ◽  
Infrared Light ◽  
Functional Near Infrared Spectroscopy ◽  
Near Infrared Light ◽  
Daily Lives ◽  
Long Run ◽  
Total Light ◽  
The Brain

Have you ever thought that light could tell you something about your brain? Light is a powerful tool that helps brain researchers understand the brain. Our eyes can only see <1% of the total light around us. Some of the light is red, so-called near-infrared light. This type of light can travel through the head and the top layers of the brain, and thereby gives researchers important information about brain activity. The technique that uses near-infrared light has a long name: functional near-infrared spectroscopy (fNIRS). In this article, we will show you what a fNIRS machine looks like and what it is like to take part in a fNIRS experiment. We will explain how we can use near-infrared light to better understand the brain. Finally, we will give you some examples of what we use fNIRS for and how it might help children who face difficulties in their daily lives in the long run.

scholarly journals Non-neuronal evoked and spontaneous hemodynamic changes in the anterior temporal region of the human head may lead to misinterpretations of functional near-infrared spectroscopy signals

2017 ◽  
Vol 5 (01) ◽  
pp. 1 ◽  
Author(s):  
Guilherne Augusto Zimeo Morais ◽  
Felix Scholkmann ◽  
Joana Bisol Balardin ◽  
Rogério Akira Furucho ◽  
Renan Costa Vieira de Paula ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Human Head ◽  
Temporal Region ◽  
Hemodynamic Changes ◽  
Functional Near Infrared Spectroscopy
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