Travis (Gus) Omer

My research is centered on optimizing and improving current optical imaging techniques. Fluorescence lifetime imaging (FLIM) is a common time-resolved fluorescence imaging technique that relies on the estimation of the fluorescence lifetime from the measured fluorescence intensity decays. The measured intensity decays are fitted to an appropriate exponential model to estimate the fluorescence lifetime. In the case of a heterogeneous population such as in Foerster resonance energy transfer (FRET), a bi-exponential model is used.

As with every model-based technique, the accuracy of lifetime estimation is dependent on numerous parameters such as the technique employed (frequency domain or time domain), signal-to-noise ratio, temporal resolution or number of time points. It is especially difficult to resolve multi-exponential decay profiles into their lifetime and amplitude coefficients if the intensity decay measurements are under-sampled. Hence, in the case of multi-exponential behaviors, the temporal profiles are typically sampled with high temporal resolution. This accurate time sampling, however, leads to lengthy acquisition times that limit the method's application in high-throughput or wide-field (e.g. whole body) applications.

I investigate the estimation accuracy of the lifetimes and fractional amplitude coefficients of a bi-exponential model when employing a limited set of time gates. Moreover, I investigate the impact of the position of the time gate selected on the parameters estimated.