scholarly journals Monitoring Local Regional Hemodynamic Signal Changes during Motor Execution and Motor Imagery Using Near-Infrared Spectroscopy

2016 ◽  
Vol 6 ◽  
Author(s):  
Naoki Iso ◽  
Takefumi Moriuchi ◽  
Akira Sagari ◽  
Eiji Kitajima ◽  
Fumiko Iso ◽  
...  
Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2362 ◽  
Author(s):  
Alexander E. Hramov ◽  
Vadim Grubov ◽  
Artem Badarin ◽  
Vladimir A. Maksimenko ◽  
Alexander N. Pisarchik

Sensor-level human brain activity is studied during real and imaginary motor execution using functional near-infrared spectroscopy (fNIRS). Blood oxygenation and deoxygenation spatial dynamics exhibit pronounced hemispheric lateralization when performing motor tasks with the left and right hands. This fact allowed us to reveal biomarkers of hemodynamical response of the motor cortex on the motor execution, and use them for designing a sensing method for classification of the type of movement. The recognition accuracy of real movements is close to 100%, while the classification accuracy of imaginary movements is lower but quite high (at the level of 90%). The advantage of the proposed method is its ability to classify real and imaginary movements with sufficiently high efficiency without the need for recalculating parameters. The proposed system can serve as a sensor of motor activity to be used for neurorehabilitation after severe brain injuries, including traumas and strokes.


1998 ◽  
Vol 89 (3) ◽  
pp. 389-394 ◽  
Author(s):  
Peter J. Kirkpatrick ◽  
Joseph Lam ◽  
Pippa Al-Rawi ◽  
Piotr Smielewski ◽  
Marek Czosnyka

Object. Signal changes in adult extracranial tissues may have a profound effect on cerebral near-infrared spectroscopy (NIRS) measurements. During carotid surgery NIRS signals provide the opportunity to determine the relative contributions from the intra- and extracranial vascular territories, allowing for a more accurate quantification. In this study the authors applied multimodal monitoring methods to patients undergoing carotid endarterectomy and explored the hypothesis that NIRS can define thresholds for cerebral ischemia, provided extracranial NIRS signal changes are identified and removed. Relative criteria for intraoperative severe cerebral ischemia (SCI) were applied to 103 patients undergoing carotid endarterectomy. Methods. One hundred three patients underwent carotid endarterectomy. An intraoperative fall in transcranial Doppler—detected middle cerebral artery flow velocity (%ΔFV) of greater than 60% accompanied by a sustained fall in cortical electrical activity were adopted as criteria for SCI. Ipsilateral frontal NIRS recorded the total difference in concentrations of oxyhemoglobin and deoxyhemoglobin (Total ΔHbdiff). Interrupted time series analysis following clamping of the external carotid artery (ECA) and the internal carotid artery (ICA) allowed the different vascular components of Total ΔHbdiff (ECA ΔHbdiff and ICA ΔHbdiff) to be identified. Data obtained in 76 patients were deemed suitable. A good correlation between %ΔFV and ICA ΔHbdiff (r = 0.73, p < 0.0001) was evident. Sixteen patients (21%) fulfilled the criteria for SCI. All patients who demonstrated an ICA ΔHbdiff of greater than 6.8 µmol/L showed SCI, and in two patients within this group nondisabling watershed infarction developed, as seen on postoperative computerized tomography scans. No patient with an ICA ΔHbdiff less than 5 µmol/L exhibited SCI or suffered a stroke. Within the resolution of the criteria used an ICA ΔHbdiff threshold of 6.8 µmol/L provided 100% specificity for SCI, whereas an ICA ΔHbdiff less than 5 µmol/L was 100% sensitive for excluding SCI. When Total ΔHbdiff was used without removing the ECA component, no thresholds for SCI were apparent. Conclusions. Carotid endarterectomy provides a stable environment for exploring NIRS-quantified thresholds for SCI in the adult head.


Stroke ◽  
2013 ◽  
Vol 44 (4) ◽  
pp. 1091-1098 ◽  
Author(s):  
Masahito Mihara ◽  
Noriaki Hattori ◽  
Megumi Hatakenaka ◽  
Hajime Yagura ◽  
Teiji Kawano ◽  
...  

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