In vivo high-speed imaging of individual cells in fast blood flow

2006 ◽  
Vol 11 (5) ◽  
pp. 054034 ◽  
Author(s):  
Vladimir P. Zharov ◽  
Ekaterina I. Galanzha ◽  
Yulian Menyaev ◽  
Valery V. Tuchin
Keyword(s):  
Blood Flow ◽  
High Speed ◽  
High Speed Imaging

scholarly journals High-speed volumetric two-photon fluorescence imaging of neurovascular dynamics

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiang Lan Fan ◽  
Jose A. Rivera ◽  
Wei Sun ◽  
John Peterson ◽  
Henry Haeberle ◽  
...  
Keyword(s):  
Blood Flow ◽  
High Speed ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Microscopy ◽  
Fluorescence Signal ◽  
Imaging Method ◽  
Spatiotemporal Resolution ◽  
Two Photon

AbstractUnderstanding the structure and function of vasculature in the brain requires us to monitor distributed hemodynamics at high spatial and temporal resolution in three-dimensional (3D) volumes in vivo. Currently, a volumetric vasculature imaging method with sub-capillary spatial resolution and blood flow-resolving speed is lacking. Here, using two-photon laser scanning microscopy (TPLSM) with an axially extended Bessel focus, we capture volumetric hemodynamics in the awake mouse brain at a spatiotemporal resolution sufficient for measuring capillary size and blood flow. With Bessel TPLSM, the fluorescence signal of a vessel becomes proportional to its size, which enables convenient intensity-based analysis of vessel dilation and constriction dynamics in large volumes. We observe entrainment of vasodilation and vasoconstriction with pupil diameter and measure 3D blood flow at 99 volumes/second. Demonstrating high-throughput monitoring of hemodynamics in the awake brain, we expect Bessel TPLSM to make broad impacts on neurovasculature research.

scholarly journals Aberration-free volumetric high-speed imaging of in vivo retina

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Dierck Hillmann ◽  
Hendrik Spahr ◽  
Carola Hain ◽  
Helge Sudkamp ◽  
Gesa Franke ◽  
...  
Keyword(s):  
High Speed ◽  
High Speed Imaging

scholarly journals Coherent Raman Scattering Microscopy in Oncology Pharmacokinetic Research

2021 ◽  
Vol 12 ◽  
Author(s):  
Junjie Zeng ◽  
Wenying Zhao ◽  
Shuhua Yue
Keyword(s):  
Raman Scattering ◽  
High Speed ◽  
Cancer Drug ◽  
Cancer Drugs ◽  
High Speed Imaging ◽  
Coherent Raman Scattering ◽  
Anti Cancer ◽  
Coherent Raman

The high attrition rates of anti-cancer drugs during clinical development remains a bottleneck problem in pharmaceutical industry. This is partially due to the lack of quantitative, selective, and rapid readouts of anti-cancer drug activity in situ with high resolution. Although fluorescence microscopy has been commonly used in oncology pharmacological research, fluorescent labels are often too large in size for small drug molecules, and thus may disturb the function or metabolism of these molecules. Such challenge can be overcome by coherent Raman scattering microscopy, which is capable of chemically selective, highly sensitive, high spatial resolution, and high-speed imaging, without the need of any labeling. Coherent Raman scattering microscopy has tremendously improved the understanding of pharmaceutical materials in the solid state, pharmacokinetics of anti-cancer drugs and nanocarriers in vitro and in vivo. This review focuses on the latest applications of coherent Raman scattering microscopy as a new emerging platform to facilitate oncology pharmacokinetic research.

scholarly journals Design and Optimization of a Linear Wavenumber Spectrometer with Cylindrical Optics for Line Scanning Optical Coherence Tomography

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6463
Author(s):  
Sevin Samadi ◽  
Javad Dargahi ◽  
Sivakumar Narayanswamy
Keyword(s):  
Optical Coherence Tomography ◽  
Image Quality ◽  
High Speed ◽  
High Efficiency ◽  
Optical Design ◽  
Optical Coherence ◽  
High Speed Imaging ◽  
Nonlinearity Error ◽  
Line Scanning

We report the design of a high-efficiency spectral-domain spectrometer with cylindrical optics for line scanning optical coherence tomography (OCT). The spectral nonlinearity in k space (wavenumber) lowers the depth-dependent signal sensitivity of the spectrometers. For linearizing, in this design, grating and prism have been introduced. For line scanning, a cylindrical mirror is utilized in the scanning part. Line scanning improves the speed of imaging compared to fly-spot scanning. Line scanning OCT requires a spectrometer that utilizes cylindrical optics. In this work, an optical design of a linear wavenumber spectrometer with cylindrical optics is introduced. While there are many works using grating and prism to linearize the K space spectrometer design, there is no work on linearizing the k-space spectrometer with cylindrical optics for line scanning that provides high sensitivity and high-speed imaging without the need for resampling. The design of the spectrometer was achieved through MATLAB and ZEMAX simulations. The spectrometer design is optimized for the broadband light source with a center wavelength of 830 ± 100 nm (8.607 μm−1− 6.756 μm−1 in k-space). The variation in the output angle with respect to the wavenumber can be mentioned as a nonlinearity error. From our design results, it is observed that the nonlinearity error reduced from 147.0115 to 0.0149 Δθ*μm within the wavenumber range considered. The use of the proposed reflective optics for focusing reduces the chromatic aberration and increases image quality (measured by the Strehl ratio (SR)). The complete system will provide clinicians a powerful tool for real-time diagnosis, treatment, and guidance in surgery with high image quality for in-vivo applications.

Ethanol effects on cardiomyocyte contractility

2000 ◽  
Vol 98 (4) ◽  
pp. 401-407 ◽  
Author(s):  
Leanne M. D. DELBRIDGE ◽  
Pamela J. CONNELL ◽  
Peter J. HARRIS ◽  
Trefor O. MORGAN
Keyword(s):  
High Speed ◽  
Imaging Techniques ◽  
Cardiac Contractility ◽  
Ethanol Exposure ◽  
High Speed Imaging ◽  
Low Concentrations ◽  
Cardiomyocyte Contractility ◽  
Contraction Cycle ◽  
Kinetics Of

Little is known about the direct cardiac effects of socially common sub-intoxication levels of ethanol. Previous studies evaluating the responses of normal cardiomyocytes to short-term ethanol exposure have utilized ethanol concentrations equivalent to extreme intoxication or lethal levels in vivo. The purpose of the present study was to investigate the contractile responses of isolated rat ventricular cardiomyocytes during exposure to relatively low concentrations of ethanol in the range 0.05–0.5% (v/v) (8.6–86 mM) under physiological conditions (3 Hz stimulation; 36 °C; BSA vehicle). High-speed imaging techniques were used to study the kinetics of myocyte contraction, and shortening parameters were calculated for mechanistic evaluation. The concentration–response relationship was not linear and exhibited two plateau phases, suggesting at least two mechanisms of action of ethanol on cardiomyocyte contraction. At 0.05% (8.6 mM), ethanol treatment produced a 14.4% decrease in maximum myocyte shortening. The maximum rates of cell shortening and lengthening were similarly impaired, but there was no effect on contraction cycle timing at this low concentration. At 0.30% (51 mM), ethanol reduced maximum shortening by 40.2%, prolonged excitation–contraction coupling latency and abbreviated the contraction cycle time by 38%. The inotropic modulatory effect of ethanol was exaggerated in the absence of protein in the superfusion buffer. This is the first report which identifies ethanol at 0.05% (v/v) as a modulator of cardiac contractility. Kinetic analyses indicate that the mechanism of action involves disturbance of sarcoplasmic reticulum function, and this may contribute to arrhythmogenic vulnerability – especially in an in vivo context of heightened compensatory sympathetic drive.

Dynamics of flow velocities in endocardial and epicardial coronary arterioles

2005 ◽  
Vol 288 (4) ◽  
pp. H1598-H1603 ◽  
Author(s):  
Eiji Toyota ◽  
Yasuo Ogasawara ◽  
Osamu Hiramatsu ◽  
Hiroyuki Tachibana ◽  
Fumihiko Kajiya ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Velocity ◽  
High Speed ◽  
Maximum Velocity ◽  
Retrograde Flow ◽  
Measurable Velocity ◽  
Blood Flow Velocities ◽  
Coronary Arterioles ◽  
Flow Velocities

The subendocardium is the most vulnerable area of the left ventricle to the effects of hypoperfusion and ischemia. Despite this well-acknowledged observation, the mechanisms underlying this susceptibility are not elucidated, although numerous explanations including differences in transmural distribution of hemodynamics, metabolism, and wall stresses have been proposed. Our goal was to make dynamic measurements of endocardial and epicardial flow velocities, which reflect hemodynamic and wall stresses, to approach this problem. We measured blood flow velocities in subendocardial and subepicardial coronary arterioles of in vivo beating canine hearts using a high-speed, charge-coupled device, intravital videomicroscope with a rod-probe lens. Subendocardial flow was characterized by remarkable systolic flow-velocity reversal (systolic slosh ratio, 84%; measurable velocity of retrograde flow, faster than −40 mm/s), which contrasted to predominant forward-flow velocity during systole in the subepicardial arterioles (systolic slosh ratio, 25%; maximum velocity, approximately −20 mm/s; P < 0.0005 and 0.05 vs. subendocardial arterioles, respectively). We speculate that this retrograde flow is “wasteful,” because this volume must be refilled during the subsequent diastole, which thereby detracts from the net perfusion as well as the time for perfusion. Accordingly, we also believe that the retrograde systolic blood flow contributes to the vulnerability of the subendocardium to ischemia.

scholarly journals MiniFAST: A sensitive and fast miniaturized microscope for in vivo neural recording

2020 ◽  
Author(s):  
Jill Juneau ◽  
Guillaume Duret ◽  
Joshua P. Chu ◽  
Alexander V. Rodriguez ◽  
Savva Morozov ◽  
...  
Keyword(s):  
Open Source ◽  
High Speed ◽  
High Sensitivity ◽  
High Gain ◽  
Image Sensor ◽  
High Speed Imaging ◽  
Light Power ◽  
Excitation Light

AbstractObserving the activity of large populations of neurons in vivo is critical for understanding brain function and dysfunction. The use of fluorescent genetically-encoded calcium indicators (GECIs) in conjunction with miniaturized microscopes is an exciting emerging toolset for recording neural activity in unrestrained animals. Despite their potential, current miniaturized microscope designs are limited by using image sensors with low frame rates, sensitivity, and resolution. Beyond GECIs, there are many neuroscience applications which would benefit from the use of other emerging neural indicators, such as fluorescent genetically-encoded voltage indicators (GEVIs) that have faster temporal resolution to match neuron spiking, yet, require imaging at high speeds to properly sample the activity-dependent signals. We integrated an advanced CMOS image sensor into a popular open-source miniaturized microscope platform. MiniFAST is a fast and sensitive miniaturized microscope capable of 1080p video, 1.5 µm resolution, frame rates up to 500 Hz and high gain ability (up to 70 dB) to image in extremely low light conditions. We report results of high speed 500 Hz in vitro imaging of a GEVI and ∼300 Hz in vivo imaging of transgenic Thy1-GCaMP6f mice. Finally, we show the potential for a reduction in photobleaching by using high gain imaging with ultra-low excitation light power (0.05 mW) at 60 Hz frame rates while still resolving Ca2+ spiking activity. Our results extend miniaturized microscope capabilities in high-speed imaging, high sensitivity and increased resolution opening the door for the open-source community to use fast and dim neural indicators.

scholarly journals High-speed imaging of human retina in vivo with swept-source optical coherence tomography

2006 ◽  
Vol 14 (26) ◽  
pp. 12902 ◽  
Author(s):  
H. Lim ◽  
M. Mujat ◽  
C. Kerbage ◽  
E. C. W. Lee ◽  
Y. Chen ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
High Speed ◽  
Human Retina ◽  
Optical Coherence ◽  
High Speed Imaging ◽  
Swept Source

scholarly journals In vivo dynamic human retinal blood flow imaging using ultra-high-speed spectral domain optical Doppler tomography

2003 ◽  
Vol 11 (25) ◽  
pp. 3490 ◽  
Author(s):  
Brian R. White ◽  
Mark C. Pierce ◽  
Nader Nassif ◽  
Barry Cense ◽  
B. Hyle Park ◽  
...  
Keyword(s):  
Blood Flow ◽  
High Speed ◽  
Retinal Blood Flow ◽  
Spectral Domain ◽  
Flow Imaging ◽  
Doppler Tomography ◽  
Blood Flow Imaging ◽  
Ultra High Speed ◽  
Optical Doppler Tomography
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