Detect
Cancer with our 4 Picos ICCD camera
Boost your results
from Fluorescence Lifetime Imaging Microscopy by
using
a sub-nanosecond ICCD Camera in time-resolved FLIM and forget about
intensity calibration.
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Detect Cancer with STANFORD COMPUTER
OPTICS' 4 Picos ICCD Camera in
Time-resolved Picosecond
Flourescence
Lifetime Imaging Microscopy - FLIM
Earlier spectroscopic studies on carcinoma and
cervical cancer
demonstrated that fluorescence
emission of diseased tissue shows red
shift in spectrum, weaker intensity and decreased lifetimes.
Investigations scored the auto fluorescence intensities, thus requiring
an
absolute calibration of the microscope or camera system. |
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Whereas
this
is a very demanding issue which introduces high uncertainties, the
direct time-resolved measurement of the fluorescence decay gives
highly precise lifetime data without any need for calibration. With
gating times down to 200
picoseconds our 4
Picos ICCD camera family provides
you with the technological advance to meet this challenge. Our
small-sized all-in-one-head camera design allows you to set up
fully portable FLIM
systems for endoscopic in vivo
diagnosis even in
clinical applications.
Read more ... |
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How
does Time-Resolved Picosecond Fluorescence Lifetime Imagig Microscopy
work?
The fluorescence
is
excited by a laser pulse at
appropriate
wavelengths.
Because the auto fluorescence typically decays with lifetimes on the
scale of 1ns the excitation pulse of the laser has to be even shorter.
The picture below scematically shows periodically appearing excitation
pulses and the according decay curves of the auto fluorescence signal.
The decay lifetime is measured with our 4 Picos ICCD camera,
that can
be gated as short as 200ps. The vertical bars in the picture show the
points in time where the camera is gated, i.e. where the shutter is
opened. As can be seen, the gating windows scan the decay curve
starting from the point of excitation down to minimum intensity. This
scan is easily performed by increasing the time delay of the gating
window with respect to the point of excitation. Our programmable
built-in trigger delay unit provides these delay intervals that can be
adjusted in steps of 10ps starting at zero.
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Because
the measured lifetime does not depend on the absolute intensity
level of the fluorescence signal, the measurement needs not to be
calibrated in any way. It only depends on the absolute accuracy of the
cameras built-in time base which is better than 20ps in our ICCD
systems.
Despite of the single photon counting capability of our ICCD cameras
each single scan shown in the picture is indeed acquired as a multiple
exposure sequence to provide outstanding signal to noise ratio and
image quality. The multiple exposure repetition rate may be set as fast
as 10MHz.
To maintain the resolution offered by the time-resolved FLIM it is
inevitable that the ICCD camera provides a real rectangular shutter
transmission characteristic to prevent non-correctable convolution
effects. Whereas such effects would usually be introduced by the
typical gaussian-like shutter characteristics of standard ICCD cameras
available
on the market, STANFORD COMPUTER OPTICS spares no efforts to provide real rectangular shutter
transmission rivalling
the physical limits.
The time-resolved FLIM
is an imaging technique that completely avoids
the need for spatial scanning. The excitation laser optics and the
imaging optics can be even integrated in an endoscope
thereby
allowing
for minimum invasive in
vivo diagnosis even in clinical applications. |
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Endoscopic FLIM system
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1
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ICCC camera 4 Picos
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2
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Pulsed nitrogen laser
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3
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Optical fiber imaging bundle
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4
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Filter wheel
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© Courtesy of Yinghua Sun, Dept. of
Biomedical Engineering, UC Davis, CA
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More applications will come up soon.
Please visit us again.
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