scholarly journals Photogrammetry-based stereoscopic optode registration method for functional near-infrared spectroscopy

2020 ◽  
Vol 25 (09) ◽  
Author(s):  
Xiao-Su Hu ◽  
Neelima Wagley ◽  
Akemi Tsutsumi Rioboo ◽  
Alexandre F. DaSilva ◽  
Ioulia Kovelman

: Functional near infrared spectroscopy (fNIRS) is an imaging system that can measure hemodynamic changes of the brain. However, the system incapability to measure beyond the brain cortex region make it usage less appealing for in-depth brain studies. To overcome this, many researchers combine fNIRS with other imaging modalities to gain better understanding of the brain activities. In this paper, we described the theory of the registering fNIRS signals and positron emission tomography (PET) image method and performed experiments to validate it. The registration method was validated using specially designed phantom for fNIRS and PET. Polaris system was used to track the position of the phantom which is based on the Polaris markers during fNIRS and PET procedures. The Polaris markers share the same coordinate, thus the fNIRS and PET were calibrated to each other through these markers. To register the fNIRS signal on the PET image, the phantom position in fNIRS coordinate is translated to PET coordinate which allow the probe and the markers being coordinated in PET. Polaris markers were used as the references marker to determine the transformation matrices. The result shows that the fNIRS channel can be viewed on the PET image of the phantom. The transformation error from Polaris to PET is less than 1.00 mm and the precision test is less than 0.1mm while the accuracy is less than 2.8 mm. This result suggests that our theory on the registration method could be used for multimodal image registration between fNIRS and other modalities.


Author(s):  
S. Srilekha ◽  
B. Vanathi

This paper focuses on electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) comparison to help the rehabilitation patients. Both methods have unique techniques and placement of electrodes. Usage of signals are different in application based on the economic conditions. This study helps in choosing the signal for the betterment of analysis. Ten healthy subject datasets of EEG & FNIRS are taken and applied to plot topography separately. Accuracy, Sensitivity, peaks, integral areas, etc are compared and plotted. The main advantages of this study are to prompt their necessities in the analysis of rehabilitation devices to manage their life as a typical individual.


Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 61-LB
Author(s):  
LISA R. LETOURNEAU-FREIBERG ◽  
KIMBERLY L. MEIDENBAUER ◽  
ANNA M. DENSON ◽  
PERSEPHONE TIAN ◽  
KYOUNG WHAN CHOE ◽  
...  

2019 ◽  
Author(s):  
Shannon Burns ◽  
Matthew D. Lieberman

Social and affective neuroscience studies the neurophysiological underpinnings of psychological experience and behavior as it relates to the world around us. Yet, most neuroimaging methods require the removal of participants from their rich environment and the restriction of meaningful interaction with stimuli. In this Tools of the Trade article, we explain functional near infrared spectroscopy (fNIRS) as a neuroimaging method that can address these concerns. First, we provide an overview of how fNIRS works and how it compares to other neuroimaging methods common in social and affective neuroscience. Next, we describe fNIRS research that highlights its usefulness to the field – when rich stimuli engagement or environment embedding is needed, studies of social interaction, and examples of how it can help the field become more diverse and generalizable across participant populations. Lastly, this article describes how to use fNIRS for neuroimaging research with points of advice that are particularly relevant to social and affective neuroscience studies.


2021 ◽  
Vol 18 ◽  
pp. 100272
Author(s):  
Alexander von Lühmann ◽  
Yilei Zheng ◽  
Antonio Ortega-Martinez ◽  
Swathi Kiran ◽  
David C. Somers ◽  
...  

2021 ◽  
Vol 11 (6) ◽  
pp. 701
Author(s):  
Cheng-Hsuan Chen ◽  
Kuo-Kai Shyu ◽  
Cheng-Kai Lu ◽  
Chi-Wen Jao ◽  
Po-Lei Lee

The sense of smell is one of the most important organs in humans, and olfactory imaging can detect signals in the anterior orbital frontal lobe. This study assessed olfactory stimuli using support vector machines (SVMs) with signals from functional near-infrared spectroscopy (fNIRS) data obtained from the prefrontal cortex. These data included odor stimuli and air state, which triggered the hemodynamic response function (HRF), determined from variations in oxyhemoglobin (oxyHb) and deoxyhemoglobin (deoxyHb) levels; photoplethysmography (PPG) of two wavelengths (raw optical red and near-infrared data); and the ratios of data from two optical datasets. We adopted three SVM kernel functions (i.e., linear, quadratic, and cubic) to analyze signals and compare their performance with the HRF and PPG signals. The results revealed that oxyHb yielded the most efficient single-signal data with a quadratic kernel function, and a combination of HRF and PPG signals yielded the most efficient multi-signal data with the cubic function. Our results revealed superior SVM analysis of HRFs for classifying odor and air status using fNIRS data during olfaction in humans. Furthermore, the olfactory stimulation can be accurately classified by using quadratic and cubic kernel functions in SVM, even for an individual participant data set.


2021 ◽  
Vol 11 (8) ◽  
pp. 968
Author(s):  
Roger C. Ho ◽  
Vijay K. Sharma ◽  
Benjamin Y. Q. Tan ◽  
Alison Y. Y. Ng ◽  
Yit-Shiang Lui ◽  
...  

Impaired sense of smell occurs in a fraction of patients with COVID-19 infection, but its effect on cerebral activity is unknown. Thus, this case report investigated the effect of COVID-19 infection on frontotemporal cortex activity during olfactory stimuli. In this preliminary study, patients who recovered from COVID-19 infection (n = 6) and healthy controls who never contracted COVID-19 (n = 6) were recruited. Relative changes in frontotemporal cortex oxy-hemoglobin during olfactory stimuli was acquired using functional near-infrared spectroscopy (fNIRS). The area under curve (AUC) of oxy-hemoglobin for the time interval 5 s before and 15 s after olfactory stimuli was derived. In addition, olfactory function was assessed using the Sniffin’ Sticks 12-identification test (SIT-12). Patients had lower SIT-12 scores than healthy controls (p = 0.026), but there were no differences in oxy-hemoglobin AUC between healthy controls and patients (p > 0.05). This suggests that past COVID-19 infection may not affect frontotemporal cortex function, and these preliminary results need to be verified in larger samples.


Sign in / Sign up

Export Citation Format

Share Document