Detect Cancer with our 4 Picos ICCD camera
Detect Cancer with the 4 Picos ICCD Camera from Stanford Computer Optics in time-resolved Picosecond Flourescence Lifetime Imaging Microscopy (FLIM).
Time resolved sub-nanosecond fluorescence lifetime imaging microscopy using a 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.
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. 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.
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.
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.