scholarly journals Time-Domain Near-Infrared Spectroscopy and Imaging: A Review

2019 ◽  
Vol 9 (6) ◽  
pp. 1127 ◽  
Author(s):  
Yukio Yamada ◽  
Hiroaki Suzuki ◽  
Yutaka Yamashita

This article reviews the past and current statuses of time-domain near-infrared spectroscopy (TD-NIRS) and imaging. Although time-domain technology is not yet widely employed due to its drawbacks of being cumbersome, bulky, and very expensive compared to commercial continuous wave (CW) and frequency-domain (FD) fNIRS systems, TD-NIRS has great advantages over CW and FD systems because time-resolved data measured by TD systems contain the richest information about optical properties inside measured objects. This article focuses on reviewing the theoretical background, advanced theories and methods, instruments, and studies on clinical applications for TD-NIRS including some clinical studies which used TD-NIRS systems. Major events in the development of TD-NIRS and imaging are identified and summarized in chronological tables and figures. Finally, prospects for TD-NIRS in the near future are briefly described.

Author(s):  
Patrick Poulet ◽  
Marine Amouroux ◽  
Wilfried Uhring ◽  
Thierry Pebayle ◽  
Renée Chabrier ◽  
...  

2016 ◽  
Vol 28 (2) ◽  
pp. 275-285 ◽  
Author(s):  
Goutham Ganesan ◽  
Szu-yun Leu ◽  
Albert Cerussi ◽  
Bruce Tromberg ◽  
Dan M. Cooper ◽  
...  

Near-infrared spectroscopy has long been used to measure tissue-specific O2 dynamics in exercise, but most published data have used continuous wave devices incapable of quantifying absolute Hemoglobin (Hb) concentrations. We used time-resolved near-infrared spectroscopy to study exercising muscle (Vastus Lateralis, VL) and prefrontal cortex (PFC) Hb oxygenation in 11 young males (15.3 ± 2.1 yrs) performing incremental cycling until exhaustion (peak VO2 = 42.7 ± 6.1 ml/min/kg, mean peak power = 181 ± 38 W). Time-resolved near-infrared spectroscopy measurements of reduced scattering (µs´) and absorption (µa) at three wavelengths (759, 796, and 833 nm) were used to calculate concentrations of oxyHb ([HbO2]), deoxy Hb ([HbR]), total Hb ([THb]), and O2 saturation (stO2). In PFC, significant increases were observed in both [HbO2] and [HbR] during intense exercise. PFC stO2% remained stable until 80% of total exercise time, then dropped (−2.95%, p = .0064). In VL, stO2% decreased until peak time (−6.8%, p = .01). Segmented linear regression identified thresholds for PFC [HbO2], [HbR], VL [THb]. There was a strong correlation between timing of second ventilatory threshold and decline in PFC [HbO2] (r = .84). These findings show that time-resolved near-infrared spectroscopy can be used to study physiological threshold phenomena in children during maximal exercise, providing insight into tissue specific hemodynamics and metabolism.


2019 ◽  
Vol 9 (11) ◽  
pp. 2366 ◽  
Author(s):  
Laura Di Sieno ◽  
Alberto Dalla Mora ◽  
Alessandro Torricelli ◽  
Lorenzo Spinelli ◽  
Rebecca Re ◽  
...  

In this paper, a time-domain fast gated near-infrared spectroscopy system is presented. The system is composed of a fiber-based laser providing two pulsed sources and two fast gated detectors. The system is characterized on phantoms and was tested in vivo, showing how the gating approach can improve the contrast and contrast-to-noise-ratio for detection of absorption perturbation inside a diffusive medium, regardless of source-detector separation.


PEDIATRICS ◽  
1993 ◽  
Vol 92 (1) ◽  
pp. 190-190

In the article, "A Report of the National Institute of Neurological Disorders and Stroke Workshop on Near Infrared Spectroscopy" by Hirtz (Pediatrics. 1993;91:414-417), on page 416, middle of the second paragraph, "The accuracy of time-resolved methods is 30% of saturation..." should read "The accuracy of time resolved methods is 3% of saturation ..."


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