scholarly journals The Effect of Motion Artifacts on Near-Infrared Spectroscopy (NIRS) Data and Proposal of a Video-NIRS System

2017 ◽  
Vol 7 (3) ◽  
pp. 406-418
Author(s):  
Masayuki Satoh ◽  
Keisuke Okamoto ◽  
Ken-ichi Tabei ◽  
Hirotaka Kida ◽  
Hidekazu Tomimoto ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Blood Oxygen Level Dependent ◽  
Motion Artifacts ◽  
Video Capture ◽  
Blood Oxygen Level ◽  
Word Fluency ◽  
Nirs Data ◽  
Hb Concentration

Aims: The aims of this study were (1) to investigate the influence of physical movement on near-infrared spectroscopy (NIRS) data, (2) to establish a video-NIRS system which simultaneously records NIRS data and the subject’s movement, and (3) to measure the oxygenated hemoglobin (oxy-Hb) concentration change (Δoxy-Hb) during a word fluency (WF) task. Experiment 1: In 5 healthy volunteers, we measured the oxy-Hb and deoxygenated hemoglobin (deoxy-Hb) concentrations during 11 kinds of facial, head, and extremity movements. The probes were set in the bilateral frontal regions. The deoxy-Hb concentration was increased in 85% of the measurements. Experiment 2: Using a pillow on the backrest of the chair, we established the video-NIRS system with data acquisition and video capture software. One hundred and seventy-six elderly people performed the WF task. The deoxy-Hb concentration was decreased in 167 subjects (95%). Experiment 3: Using the video-NIRS system, we measured the Δoxy-Hb, and compared it with the results of the WF task. Δoxy-Hb was significantly correlated with the number of words. Conclusion: Like the blood oxygen level-dependent imaging effect in functional MRI, the deoxy-Hb concentration will decrease if the data correctly reflect the change in neural activity. The video-NIRS system might be useful to collect NIRS data by recording the waveforms and the subject’s appearance simultaneously.

scholarly journals Study of the FMRI blood oxygen level dependent effect by near-infrared spectroscopy

2003 ◽  
Author(s):  
Vladislav Toronov ◽  
Andrew Webb ◽  
Scott Walker ◽  
Rajarsi Gupta ◽  
Jee H. Choi ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Blood Oxygen Level Dependent ◽  
Blood Oxygen ◽  
Oxygen Level ◽  
Blood Oxygen Level ◽  
Dependent Effect

scholarly journals Motion Artifact Correction of Multi-Measured Functional Near-Infrared Spectroscopy Signals Based on Signal Reconstruction Using an Artificial Neural Network

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2957 ◽  
Author(s):  
Gihyoun Lee ◽  
Sang Jin ◽  
Jinung An
Keyword(s):  
Neural Network ◽  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Motion Artifact ◽  
Correction Method ◽  
Motion Artifacts ◽  
Functional Near Infrared Spectroscopy ◽  
Artifact Correction ◽  
Performance Evaluation Index

In this paper, a new motion artifact correction method is proposed based on multi-channel functional near-infrared spectroscopy (fNIRS) signals. Recently, wavelet transform and hemodynamic response function-based algorithms were proposed as methods of denoising and detrending fNIRS signals. However, these techniques cannot achieve impressive performance in the experimental environment with lots of movement such as gait and rehabilitation tasks because hemodynamic responses have features similar to those of motion artifacts. Moreover, it is difficult to correct motion artifacts in multi-measured fNIRS systems, which have multiple channels and different noise features in each channel. Thus, a new motion artifact correction method for multi-measured fNIRS is proposed in this study, which includes a decision algorithm to determine the most contaminated fNIRS channel based on entropy and a reconstruction algorithm to correct motion artifacts by using a wavelet-decomposed back-propagation neural network. The experimental data was achieved from six subjects and the results were analyzed in comparing conventional algorithms such as HRF smoothing, wavelet denoising, and wavelet MDL. The performance of the proposed method was proven experimentally using the graphical results of the corrected fNIRS signal, CNR that is a performance evaluation index, and the brain activation map.

scholarly journals Algorithm construction methodology for diagnostic classification of near-infrared spectroscopy data

2011 ◽  
Vol 25 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Ramón Guevara ◽  
Lynn Stothers ◽  
Andrew Macnab
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Pelvic Floor Muscle ◽  
Classification And Regression Tree ◽  
Data Sets ◽  
Linear Discriminant ◽  
Cart Analysis ◽  
Chromophore Concentration ◽  
Nirs Data

Background: Near-infrared spectroscopy (NIRS) has recognized potential but limited application for non-invasive diagnostic evaluation. Data analysis methodology that reproducibly distinguishes between the presence or absence of physiologic abnormality could broaden clinical application of this optical technique.Methods: Sample data sets from simultaneous NIRS bladder monitoring and invasive urodynamic pressure-flow studies (UDS) are used to illustrate how a diagnostic algorithm is constructed using classification and regression tree (CART) analysis. Misclassification errors of CART and linear discriminant analysis (LDA) are computed and examples of other urological NIRS data likely amenable to CART analysis presented.Results: CART generated a clinically relevant classification algorithm (error 4%) using 46 data sets of changes in chromophore concentration composed of the whole time series without specifying features. LDA did not (error 16%). Using CART NIRS data provided comparable discriminant ability to the UDS diagnostic nomogram for the presence or absence of obstructive pathology (88% specificity, 84% precision). Pilot data examples from children with and without voiding dysfunction and women with mild or severe pelvic floor muscle dysfunction also show potentially diagnostic differences in chromophore concentration.Conclusions: CART analysis can likely be applied in other NIRS monitoring applications intended to classify patients into those with and without pathology.

Human calf microvascular compliance measured by near-infrared spectroscopy

2000 ◽  
Vol 88 (2) ◽  
pp. 369-372 ◽  
Author(s):  
T. Binzoni ◽  
V. Quaresima ◽  
M. Ferrari ◽  
E. Hiltbrand ◽  
P. Cerretelli
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Region Of Interest ◽  
Venous System ◽  
Vasomotor Response ◽  
Head Up Tilt ◽  
Nirs Data ◽  
The Subject ◽  
Human Calf

The purpose of this study is to develop a new method for the measurement in humans of the compliance of the microvascular superficial venous system of the lower limb by near-infrared spectroscopy (NIRS). This method is complementary to strain-gauge plethysmography, which does not allow compliance between deep and superficial venous or between venous and arterial compartments to be distinguished. In practice, hydrostatic pressure (P) changes were induced in a calf region of interest by head-up tilt of the subject from α = −10 to 75°. For P ≤ 24 mmHg, the measured compliance [0.086 ± 0.005 (SD) ml ⋅ l− 1 ⋅ mmHg− 1] based on NIRS data of total, deoxygenated, and oxygenated hemoglobin, reflects essentially that of the superficial venous system. For P ≥ 24 mmHg, no distinction can be made between arterial and venous volumes changes. However, by following the changes in oxy- and deoxyhemoglobin in the P range −16 to 100 mmHg, it appears to be possible to assess the characteristics of the vasomotor response of the arteriolar system.

scholarly journals Understanding near infrared spectroscopy and its application to skeletal muscle research

2019 ◽  
Vol 126 (5) ◽  
pp. 1360-1376 ◽  
Author(s):  
Thomas J. Barstow
Keyword(s):  
Skeletal Muscle ◽  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Oxygen Delivery ◽  
Near Infrared ◽  
Control Mechanisms ◽  
Oxygen Utilization ◽  
Muscle Research ◽  
Athletic Field ◽  
Nirs Data

Near infrared spectroscopy (NIRS) is a powerful noninvasive tool with which to study the matching of oxygen delivery to oxygen utilization and the number of new publications utilizing this technique has increased exponentially in the last 20 yr. By measuring the state of oxygenation of the primary heme compounds in skeletal muscle (hemoglobin and myoglobin), greater understanding of the underlying control mechanisms that couple perfusive and diffusive oxygen delivery to oxidative metabolism can be gained from the laboratory to the athletic field to the intensive care unit or emergency room. However, the field of NIRS has been complicated by the diversity of instrumentation, the inherent limitations of some of these technologies, the associated diversity of terminology, and a general lack of standardization of protocols. This Cores of Reproducibility in Physiology (CORP) will describe in basic but important detail the most common methodologies of NIRS, their strengths and limitations, and discuss some of the potential confounding factors that can affect the quality and reproducibility of NIRS data. Recommendations are provided to reduce the variability and errors in data collection, analysis, and interpretation. The goal of this CORP is to provide readers with a greater understanding of the methodology, limitations, and best practices so as to improve the reproducibility of NIRS research in skeletal muscle.

Near-Infrared Spectroscopy: A Tool for Diagnosing Necrotizing Enterocolitis at Onset of Symptoms in Preterm Neonates with Acute Gastrointestinal Symptoms?

2020 ◽  
Author(s):  
Julia Le Bouhellec ◽  
Olivier Prodhomme ◽  
Thibault Mura ◽  
Aurélien Jacquot ◽  
Clémentine Combes ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Necrotizing Enterocolitis ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Cerebral Oxygenation ◽  
Gastrointestinal Symptoms ◽  
Abdominal Distension ◽  
Tissue Oxygen Saturation ◽  
Preterm Neonates ◽  
Nirs Data

Abstract Objective In premature neonates, bloody stools and/or abdominal distension with feeding intolerance may be inaugural signs of necrotizing enterocolitis (NEC). We assessed the ability of near-infrared spectroscopy (NIRS) to distinguish those neonates with NEC soon after the occurrence of these symptoms. Study Design We prospectively collected NIRS measurements of abdominal and cerebral regional tissue oxygen saturation (r-SO2), with values masked by an opaque cover. Two physicians, blinded to the NIRS data, determined whether the gastrointestinal symptoms were related to NEC 10 days after symptom onset. Results Forty-five neonates with mean (standard deviation [SD]) gestational, birth weight and postnatal ages of 31 (3.9) weeks, 1,486 (794) g, and 18 (14) days were enrolled over 30 months. Gastrointestinal symptoms were related to NEC in 23 patients and associated with other causes in 22. Analysis of the 48 hours of monitoring revealed comparable abdominal r-SO2 and splanchnic-cerebral oxygenation ratio (SCOR) in patients with and without NEC (r-SO2: 47.3 [20.4] vs. 50.4 [17.8], p = 0.59, SCOR: 0.64 [0.26] vs. 0.69 [0.24], p = 0.51). Results were unchanged after NIRS analysis in 6-hour periods, and restriction of the analysis to severe NEC (i.e., grade 2 and 3, 57% of the NEC cases). Conclusion In this study, NIRS monitoring was unable to individualize NEC in premature infants with acute gastrointestinal symptoms.

scholarly journals Using a Portable Near-infrared Spectroscopy Device to Estimate The Second Ventilatory Threshold

2021 ◽  
Author(s):  
Víctor Rodrigo-Carranza ◽  
Fernando González-Mohíno ◽  
Anthony P. Turner ◽  
Sergio Rodriguez-Barbero ◽  
José María González-Ravé
Keyword(s):  
Infrared Spectroscopy ◽  
Gas Exchange ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Ventilatory Threshold ◽  
Maximum Heart Rate ◽  
Nirs Data ◽  
Trained Runners ◽  
Healthy Participants

AbstractA breakpoint in a portable near-infrared spectroscopy (NIRS) derived deoxygenated haemoglobin (deoxy[Hb]) signal during an incremental VO2max running test has been associated with the second ventilatory threshold (VT2) in healthy participants. Thus, the aim was to examine the association between this breakpoint (NIRS) and VT2 in well-trained runners. Gas exchange and NIRS data were collected during an incremental VO2max running test for 10 well-trained runners. The breakpoint calculated in oxygen saturation (StO2) and the VT2 were determined and compared in terms relative to %VO2max, absolute speed, VO2, and maximum heart rate (HRmax). There were no significant differences (p>0.05) between the breakpoint in StO2 and VT2 relative to %VO2max (87.00±6.14 and 88.28 ± 3.98 %), absolute speed (15.70±1.42 and 16.10±1.66 km·h−1), VO2 (53.71±15.17 and 54.66±15.57 ml·kg−1·min−1), and%HRmax (90.90±4.17 and 91.84±3.70%). There were large and significant correlations between instruments relative to%VO2max (r=0.68, p<0.05), absolute speed (r=0.86, p<0.001), VO2 (r=0.86, p<0.001), and %HRmax (r=0.69; p<0.05). A Bland and Altman analysis of agreement between instruments resulted in a mean difference of − 1.27±4.49%, −0.40±0.84 km·h−1,−0.90±3.07 ml·kg−1·min−1, and − 0.94±3.14 for %VO2max, absolute speed, VO2, and %HRmax, respectively. We conclude that a portable NIRS determination of the StO2 breakpoint is comparable with VT2 using gas exchange and therefore appropriate for use in determining exercise training above VT2 intensity. This is the first study to analyze the validity with the running mode using a NIRS portable device.

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