Online-FLIM at 10 images per second

We report on a technique that records and displays fluorescence lifetime images at a rate of 10 images per second. Data acquisition is based on multi-dimensional TCSPC in combination with confocal or two-photon laser scanning. The image are calculated from the TCSPC FLIM data via the first moment of the decay data in the pixels of the images. The first-moment technique combines near-ideal photon efficiency with calculation times shorter than the frame times of the commonly used galvanometer scanners. The image rate is thus not slowed down by the lifetime calculation process. Potential applications are clinical FLIM, where suspicious areas can be identified for subsequent high-accuracy imaging, and standard FLIM microscopy, where the technique it helps the user select interesting cells in a large field of view for detailed analysis.