scholarly journals Clinical Brain Monitoring with Time Domain NIRS: A Review and Future Perspectives

2019 ◽  
Vol 9 (8) ◽  
pp. 1612 ◽  
Author(s):  
Frédéric Lange ◽  
Ilias Tachtsidis
Keyword(s):  
Time Domain ◽  
Near Infrared ◽  
Haemoglobin Concentration ◽  
Tissue Oxygen Saturation ◽  
Clinical Environment ◽  
Brain Tissue Oxygenation ◽  
Physiological Information ◽  
Recent Developments ◽  
Neonatal Imaging ◽  
Brain Monitoring

Near-infrared spectroscopy (NIRS) is an optical technique that can measure brain tissue oxygenation and haemodynamics in real-time and at the patient bedside allowing medical doctors to access important physiological information. However, despite this, the use of NIRS in a clinical environment is hindered due to limitations, such as poor reproducibility, lack of depth sensitivity and poor brain-specificity. Time domain NIRS (or TD-NIRS) can resolve these issues and offer detailed information of the optical properties of the tissue, allowing better physiological information to be retrieved. This is achieved at the cost of increased instrument complexity, operation complexity and price. In this review, we focus on brain monitoring clinical applications of TD-NIRS. A total of 52 publications were identified, spanning the fields of neonatal imaging, stroke assessment, traumatic brain injury (TBI) assessment, brain death assessment, psychiatry, peroperative care, neuronal disorders assessment and communication with patient with locked-in syndrome. In all the publications, the advantages of the TD-NIRS measurement to (1) extract absolute values of haemoglobin concentration and tissue oxygen saturation, (2) assess the reduced scattering coefficient, and (3) separate between extra-cerebral and cerebral tissues, are highlighted; and emphasize the utility of TD-NIRS in a clinical context. In the last sections of this review, we explore the recent developments of TD-NIRS, in terms of instrumentation and methodologies that might impact and broaden its use in the hospital.

scholarly journals Sleep Apnea Detection And Non-Invasive Brain Tissue Oxygen Monitoring

2012 ◽  
pp. 9-14
Author(s):  
Akash Kumar Bhoi ◽  
Baidyanath Panda
Keyword(s):  
Infrared Spectroscopy ◽  
Brain Tissue ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Tissue Oxygen Saturation ◽  
Tissue Oxygen ◽  
Brain Tissue Oxygenation ◽  
Non Invasive ◽  
Brain Tissue Oxygen ◽  
Oxygen Monitoring

This paper introduces a non-invasive method for monitoring the respiratory patterns of the patients and the specifications of apnea monitor hardware. The microcontroller based apnea monitor consists of a sensor system interfaced with a microcontroller to detect the apnea from the heat changes in the oro-nazal air flow and simultaneously measure the brain tissue oxygen level by Near Infrared spectroscopy(NIRS).Near-infrared spectroscopy (NIRS) has the potential to noninvasively monitor brain tissue oxygen saturation (SO2), and changes in concentration of oxyhemoglobin [O2Hb], deoxyhemoglobin [HHb] and total haemoglobin [tHb] with real-time resolution. We hypothesized that brain tissue oxygenation would be worse during sleep in OSA relative to controls and sought to determine the practical use of NIRS in the sleep laboratory.

scholarly journals NIRS monitoring of brain and spinal cord — detection of adverse intraoperative events

2003 ◽  
Vol 17 (2-3) ◽  
pp. 483-490 ◽  
Author(s):  
Andrew J. Macnab ◽  
Roy E. Gagnon ◽  
Faith A. Gagnon ◽  
Jacques G. LeBlanc
Keyword(s):  
Spinal Cord ◽  
Near Infrared ◽  
Circulatory Arrest ◽  
Spinal Column ◽  
Haemoglobin Concentration ◽  
Standard Of Care ◽  
Redox Status ◽  
Spinal Cord Monitoring ◽  
Ischaemic Damage ◽  
Brain Monitoring

Near infrared spectroscopy (NIRS) monitors changes in oxygenated haemoglobin (HbO2), and redox status of cytochromeaa3(cyt) continuously and non-invasively in living tissue. We present examples where clinically relevant changes in HbO2and/or cyt were detected in real time, allowing intervention to avert potentially harmful hypoxic-ischaemic damage to the brain and/or spinal cord.Brain monitoring: In children undergoing surgery on cardiopulmonary bypass, observations include that: atrial fibrillation (cardiac arrhythmia) lowered cerebral HbO2concentration; concealed haemorrhage decreased cerebral HbO2concentration; inadequate level of anaesthetic resulted in spikes of changes in volume with interventions such as suturing; circulatory arrest reduced brain HbO2and cyt redox status; and bypass pump problems compromised cerebral blood flow.Spinal cord monitoring: In the experimental animal, we observed that NIRS detected ischaemic change immediately following aortic compression, spinal column distraction (instrumentation to separate the vertebrae), and hypoxia. In an infant requiring release of a congenitally tethered spinal cord, we observed that traction on the spinal cord of the infant resulted in decreased total haemoglobin concentration.Summary: NIRS brain monitoring probably represents the “standard of care” during cardiac surgery because adverse events can be detected and quantified. Similarly, spinal cord monitoring could reduce ischaemic spinal cord damage in spinal cord surgery and aortic aneurysm repair.

scholarly journals Author Correction: High-sensitivity imaging of time-domain near-infrared light transducer

2021 ◽  
Author(s):  
Yuyang Gu ◽  
Zhiyong Guo ◽  
Wei Yuan ◽  
Mengya Kong ◽  
Yulai Liu ◽  
...  
Keyword(s):  
Time Domain ◽  
Near Infrared ◽  
High Sensitivity ◽  
Infrared Light ◽  
Near Infrared Light

scholarly journals Evaluation of Different Near-Infrared Spectroscopy Devices for Assessing Tissue Oxygenation with a Vascular Occlusion Test in Healthy Volunteers

2020 ◽  
Vol 57 (6) ◽  
pp. 341-347
Author(s):  
Jaeyeon Chung ◽  
Sang-Hwan Ji ◽  
Young-Eun Jang ◽  
Eun-Hee Kim ◽  
Ji-Hyun Lee ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Pairwise Comparison ◽  
Vascular Occlusion ◽  
Tissue Oxygen Saturation ◽  
Vascular Occlusion Test ◽  
Occlusion Test ◽  
Significant Difference ◽  
Post Hoc

Near-infrared spectroscopy devices can measure peripheral tissue oxygen saturation (StO<sub>2</sub>). This study aims to compare StO<sub>2</sub> using INVOS® and different O3™ settings (O3<sup>25:75</sup> and O3<sup>30:70</sup>). Twenty adults were recruited. INVOS® and O3™ probes were placed simultaneously on 1 side of forearm. After baseline measurement, the vascular occlusion test was initiated. The baseline value, rate of deoxygenation and reoxygenation, minimum and peak StO<sub>2</sub>, and time from cuff release to peak value were measured. The parameters were compared using ANOVA and Kruskal-Wallis tests. Bonferroni’s correction and Mann-Whitney pairwise comparison were used for post hoc analysis. The agreement between StO<sub>2</sub> of devices was evaluated using Bland-Altman plots. INVOS® baseline value was higher (79.7 ± 6.4%) than that of O3<sup>25:75</sup> and O3<sup>30:70</sup> (62.4 ± 6.0% and 63.7 ± 5.5%, respectively, <i>p</i> &#x3c; 0.001). The deoxygenation rate was higher with INVOS® (10.6 ± 2.1%/min) than with O3<sup>25:75</sup> and O3<sup>30:70</sup> (8.4 ± 2.2%/min, <i>p</i> = 0.006 and 7.5 ± 2.1%/min, <i>p</i> &#x3c; 0.001). The minimum and peak StO<sub>2</sub> were higher with INVOS®. No significant difference in the reoxygenation rate was found between the devices and settings. The time to reach peak after cuff deflation was faster with INVOS® (both <i>p</i> &#x3c; 0.001). Other parameters were similar. There were no differences between the different O3™ settings. There were differences in StO<sub>2</sub> measurements between the devices, and these devices should not be interchanged. Differences were not observed between O3™ device settings.

Evaluating the dynamics of brain tissue oxygenation using near-infrared spectroscopy on various experimental models

2019 ◽  
Vol 16 (11) ◽  
pp. 115602
Author(s):  
D M Kustov ◽  
A S Sharova ◽  
V I Makarov ◽  
A V Borodkin ◽  
T A Saveleva ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Brain Tissue ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Tissue Oxygenation ◽  
Experimental Models ◽  
Brain Tissue Oxygenation

Modal Control by Modal Force Technique

1991 ◽  
Author(s):  
C. D. Tsai ◽  
M. S. Ju ◽  
Y. G. Tsuei
Keyword(s):  
Feedback Control ◽  
Control Problem ◽  
Efficient Method ◽  
Time Domain ◽  
Modal Control ◽  
Global Dynamic ◽  
Recent Developments ◽  
Modal Force ◽  
Frequency Domain Approach ◽  
Direct Feedback

Abstract Modal control of structure requires the estimation of the modal states variables for feedback. One approach that does not require modal states variables estimation is the direct feedback control. Recent developments in modal control for direct feedback are mainly time domain methods. In this paper, an efficient method based on frequency domain approach named Modal Force Technique is developed. The method not only allows one to modify the global dynamic behavior of the synthesized structure but also can be utilized for modal control problem if the acceleration, velocity and displacement feedbacks are used.

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