scholarly journals Validation of red blood cell flux and velocity estimations based on optical coherence tomography intensity fluctuations

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Paul J. Marchand ◽  
Xuecong Lu ◽  
Cong Zhang ◽  
Frédéric Lesage
Keyword(s):  
Optical Coherence Tomography ◽  
Fluorescence Microscopy ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Focal Volume ◽  
Two Photon ◽  
Photon Excitation ◽  
Speed Range ◽  
Flux Estimation ◽  
Increase In Accuracy

Abstract We present a validation of red blood cell flux and speed measurements based on the passage of erythrocytes through the OCT’s focal volume. We compare the performance of the so-called RBC-passage OCT technique to co-localized and simultaneously acquired two-photon excitation fluorescence microscopy (TPEF) measurements. Using concurrent multi-modal imaging, we show that fluctuations in the OCT signal display highly similar features to TPEF time traces. Furthermore, we demonstrate an overall difference in RBC flux and speed of 2.5 ± 3.27 RBC/s and 0.12 ± 0.67 mm/s (mean ± S.D.), compared to TPEF. The analysis also revealed that the OCT RBC flux estimation is most accurate between 20 RBC/s to 60 RBC/s, and is severely underestimated at fluxes beyond 80 RBC/s. Lastly, our analysis shows that the RBC speed estimations increase in accuracy as the speed decreases, reaching a difference of 0.16 ± 0.25 mm/s within the 0–0.5 mm/s speed range.

Two-photon excitation fluorescence microscopy in living systems

1993 ◽  
Vol 51 ◽  
pp. 154-155 ◽  
Author(s):  
David W. Piston
Keyword(s):  
Confocal Microscopy ◽  
Fluorescence Microscopy ◽  
Singlet State ◽  
Excited Electronic State ◽  
Input Power ◽  
Two Photon ◽  
Simultaneous Absorption ◽  
Photon Excitation ◽  
Very High ◽  
Two Photon Excitation

Two-photon excitation fluorescence microscopy provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging. Two-photon excitation arises from the simultaneous absorption of two photons in a single quantitized event whose probability is proportional to the square of the instantaneous intensity. For example, two red photons can cause the transition to an excited electronic state normally reached by absorption in the ultraviolet. In our fluorescence experiments, the final excited state is the same singlet state that is populated during a conventional fluorescence experiment. Thus, the fluorophore exhibits the same emission properties (e.g. wavelength shifts, environmental sensitivity) used in typical biological microscopy studies. In practice, two-photon excitation is made possible by the very high local instantaneous intensity provided by a combination of diffraction-limited focusing of a single laser beam in the microscope and the temporal concentration of 100 femtosecond pulses generated by a mode-locked laser. Resultant peak excitation intensities are 106 times greater than the CW intensities used in confocal microscopy, but the pulse duty cycle of 10−5 maintains the average input power on the order of 10 mW, only slightly greater than the power normally used in confocal microscopy.

Two‐photon excitation fluorescence microscopy using a semiconductor laser

Bioimaging ◽  
1995 ◽  
Vol 3 (2) ◽  
pp. 70-75 ◽  
Author(s):  
Pekka E Hänninen ◽  
Martin Schrader ◽  
Erkki Soini ◽  
Stefan W Hell
Keyword(s):  
Fluorescence Microscopy ◽  
Semiconductor Laser ◽  
Two Photon ◽  
Photon Excitation ◽  
Two Photon Excitation

Two-Photon Excitation Imaging of Glucose Metabolism in Living Tissue

1997 ◽  
Vol 3 (S2) ◽  
pp. 305-306
Author(s):  
David W. Piston
Keyword(s):  
Confocal Microscopy ◽  
Collection Efficiency ◽  
Three Dimensional ◽  
Spatial Filter ◽  
Input Power ◽  
Photon Absorption ◽  
Focal Volume ◽  
Two Photon ◽  
Photon Excitation ◽  
Two Photon Excitation

Two-photon excitation microscopy (TPEM) provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging and photochemistry. It provides three-dimensional resolution and eliminates background equivalent to an ideal confocal microscope without requiring a confocal spatial filter, whose absence enhances fluorescence collection efficiency. This results in inherent submicron optical sectioning by excitation alone. In practice, TPEM is made possible by the very high local instantaneous intensity provided by a combination of diffraction-limited focusing of a single laser beam in the microscope and the temporal concentration of 100 femtosecond pulses generated by a mode-locked laser. Resultant peak excitation intensities are 106 times greater than the CW intensities used in confocal microscopy, but the pulse duty cycle of 10−5 limits the average input power to less than 10 mW, only slightly greater than the power normally used in confocal microscopy. Because of the intensity-squared dependence of the two-photon absorption, the excitation is limited to the focal volume.

scholarly journals Axial Resolution Enhancement by 4Pi Confocal Fluorescence Microscopy with Two-Photon Excitation

2007 ◽  
Vol 33 (5-6) ◽  
pp. 433-443 ◽  
Author(s):  
Sylvia Glaschick ◽  
Carlheinz Röcker ◽  
Karen Deuschle ◽  
Jörg Wiedenmann ◽  
Franz Oswald ◽  
...  
Keyword(s):  
Fluorescence Microscopy ◽  
Resolution Enhancement ◽  
Confocal Fluorescence Microscopy ◽  
Axial Resolution ◽  
Two Photon ◽  
Photon Excitation ◽  
Confocal Fluorescence ◽  
Two Photon Excitation

Two-Photon Excitation Fluorescence Microscopy

2013 ◽  
pp. 2667-2671 ◽  
Author(s):  
Alberto Diaspro ◽  
Paolo Bianchini ◽  
Francesca Cella Zanacchi ◽  
Cesare Usai
Keyword(s):  
Fluorescence Microscopy ◽  
Two Photon ◽  
Photon Excitation ◽  
Two Photon Excitation
Sign in / Sign up

Export Citation Format

Share Document