Date of Award
Spring 5-12-2025
Degree Name
Master of Science (MS)
Degree Type
Thesis
Abstract
Fluorescence Lifetime Imaging Microscopy (FLIM) is a crucial tool in biomedical research. It can visualize and measure molecular interactions and cellular processes by analyzing the fluorescence decay of molecules in biological samples. Unlike traditional imaging methods based on fluorescence intensity, FLIM uses fluorescence lifetime - the time delay between excitation and emission in the fluorescence process - to provide detailed information about the biochemical environment and molecular activity.
In photon-counting systems, dead time is the short period after detecting a photon when the detection system cannot record new photons. The effect of dead time on the measured fluorescence intensity and lifetime is highly dependent on the photon rate (the number of incident photons per laser period). Dead time causes photon counts to be underestimated, especially at high photon rates, leading to errors in both fluorescence intensity and lifetime measurements. To address this issue, the Cross-Cycle computational correction method, inspired by techniques from Light Detection and Ranging (LiDAR) systems, has been developed to correct for dead time effects. The Cross-Cycle method statistically models the loss of photons within and across laser cycles, estimates the probability of photon detection, and reconstructs fluorescence intensity and lifetime. Here, we demonstrate that the Cross-Cycle method improves the accuracy of fluorescence intensity and lifetime in simulated data.
This correction allows more accurate fluorescence intensity and lifetime estimation at high photon rates, enabling faster imaging and more reliable results in FLIM.
Language
English (en)
Chair
Janet Sorrells
Committee Members
Matthew Lew, Yao Chen