Neural optical imaging can evaluate cortical hemodynamic fluctuations which reflect neural activity and disease state. We evaluate the use of vertical-cavity surface-emitting lasers (VCSELs) as illumination source for simultaneous imaging of blood flow and tissue oxygenation dynamics ex vivo and in vivo and demonstrate optical imaging of blood flow changes and oxygenation changes in response to induced ischemia. Using VCSELs we show a rapid switching from a single-mode to a special multi-mode rapid current sweep operation and noise values reduced to within a factor of 40% compared to non-coherent LED illumination. These VCSELs are promising for long-term portable continuous monitoring of brain dynamics in freely moving animals.
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http://dx.doi.org/10.1364/OE.19.010747 | DOI Listing |
Clin Exp Optom
January 2025
Department of Ophthalmology, Dokuz Eylul University, Izmir, Turkey.
Sci Rep
January 2025
Research Unit of Health Sciences and Technology, University of Oulu, Oulu, Finland.
Optical techniques, such as functional near-infrared spectroscopy (fNIRS), contain high potential for the development of non-invasive wearable systems for evaluating cerebral vascular condition in aging, due to their portability and ability to monitor real-time changes in cerebral hemodynamics. In this study, thirty-six healthy adults were measured by single channel fNIRS to explore differences between two age groups using machine learning (ML). The subjects, measured during functional magnetic resonance imaging (fMRI) at Oulu University Hospital, were divided into young (age ≤ 32) and elderly (age ≥ 57) groups.
View Article and Find Full Text PDFEye (Lond)
January 2025
Division of Clinical Neuroscience, Department of Ophthalmology, University of Nottingham, Nottingham, UK.
Background/objectives: Anterior segment optical Coherence Tomography (AS-OCT) is used extensively in imaging the cornea in health and disease. Our objective was to analyse and monitor corneal vascularisation (CVas) through the corresponding back-shadows visible on AS-OCT.
Subjects/methods: AS-OCT scans were obtained from 26 consecutive patients (eyes) with CVas of different aetiologies.
Sci Rep
January 2025
Mallinckrodt Institute of Radiology, Washington University School of Medicine, 4515 McKinley Ave., St. Louis, MO, 63110, USA.
Functional magnetic resonance imaging (fMRI) has dramatically advanced non-invasive human brain mapping and decoding. Functional near-infrared spectroscopy (fNIRS) and high-density diffuse optical tomography (HD-DOT) non-invasively measure blood oxygen fluctuations related to brain activity, like fMRI, at the brain surface, using more-lightweight equipment that circumvents ergonomic and logistical limitations of fMRI. HD-DOT grids have smaller inter-optode spacing (~ 13 mm) than sparse fNIRS (~ 30 mm) and therefore provide higher image quality, with spatial resolution ~ 1/2 that of fMRI, when using the several source-detector distances (13-40 mm) afforded by the HD-DOT grid.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Physics, Harvard University, Cambridge, MA, USA.
High-resolution fluorescence imaging of ultracold atoms and molecules is paramount to performing quantum simulation and computation in optical lattices and tweezers. Imaging durations in these experiments typically range from a millisecond to a second, significantly limiting the cycle time. In this work, we present fast, 2.
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