Biophotonic Modelling of Cardiac Optical Imaging
(15.1) where ϕ(z) is the excitation fluence as a function of depth (z). The emission profile was represented by a simple mono-exponential function, as the subsurface peak is not relevant…
Design and Use of Organic Voltage Sensitive Dyes
Fig. 2.1 Mechanisms used by VSDs that can change their location in response to membrane depolarization It would be preferable to have a mechanism that produces dyes with sensitivities that…
Optical Mapping of Ventricular Fibrillation Dynamics
(13.1) Equation (13.1) represents the hypothesis that the perimeter of the smallest possible reentrant circuit is which is a different version of the wavelength (λ) described above; APD $$ ” src=”/wp-content/uploads/2016/09/A320817_1_En_13_Chapter_IEq3.gif”>….
Random-Access Multiphoton Microscopy for Fast Three-Dimensional Imaging
Fig. 18.1 2D AOD Scanning Microscope. (a) Angular deflection (Ө) of a collimated laser beam by a single AOD with a fixed frequency (f) acoustic wave. (b) Fast scanning microscope…
Second Harmonic Imaging of Membrane Potential
Fig. 19.1 Jablonski diagrams for 1 photon fluorescence, 2PF and SHG. GS = ground state; ES = excited state; Δt = excited state lifetime To explore the origin of SHG requires consideration of how the light…
Two-Photon Excitation of Fluorescent Voltage-Sensitive Dyes: Monitoring Membrane Potential in the Infrared
. The polarization can then be approximated as a Taylor series, i.e. where the expansion coefficients are abbreviated as χ (n), defined as the nth-order electric susceptibilities. The higher order…
Imaging the Dynamics of Mammalian Neocortical Population Activity In-Vivo
Fig. 10.1 “Blue dyes”: Thirty-fold improvement in the signal-to-noise ratio. (a) Wavelength dependency of heart-beat and respiration signals. The left panel illustrates optical reflectance signals from cat visual cortex measured…
Towards Depth-Resolved Optical Imaging of Cardiac Electrical Activity
Fig. 16.1 Comparison of optical and electrical activation times in isolated rat hearts. (a) Activation map based on time of maximal upstroke velocity (tF*) following stimulation in the center of…
Imaging of Ventricular Fibrillation and Defibrillation: The Virtual Electrode Hypothesis
Fig. 14.1 (a) The leading circle concept: Activity establishes itself in the smallest pathway that can support reentry, shown as a large black arrow. Inside the leading circle, centripetal wavelets…
Imaging Submillisecond Membrane Potential Changes from Individual Regions of Single Axons, Dendrites and Spines
(3.1) where ΔF/F is the fractional fluorescence signal per unit change in Vm and Φ is the number of detected photons per unit time (fluorescence intensity expressed as photon flux)….
