Time-correlated single photon counting (TCSPC) is regarded as the “gold-standard” method for fluorescence lifetime measurements. However, TCSPC requires using highly sensitive detectors, not suitable for measurements under bright light conditions, thereby making the use impractical in clinical settings. The invention described here solves this problem by synchronizing the fluorescence detection with an external light source. This method guarantees that fluorescence and background photons are temporally resolved and the fluorescence signal is free from bright background light, which makes TCSPC measurements possible and practical under bright background conditions. The impact and applicability of this method in clinical procedures is further increased by using a fibre-optic probe for excitation light delivery and fluorescence collection. Fluorescence lifetime maps can be created and displayed from single point fibre-based measurements, to provide clinical feedback in real time.
Relative to traditional TCSPC measurements using a single point approach, this invention has the following advantages: (1) measurements can be realized under bright light illumination, which makes TCSPC acquisition possible and practical in clinical procedures; (2) fast data acquisition together with parallel computing permits data processing in real time (50 Hz) using the phasor approach, thereby providing real time feedback of the fluorescence measurements; (3) measurements are spatially resolved by adding a visual reference to be detected and segmented in real time to provide spatial feedback to the operator. Relative to Marcu et al [US 2017/0370843 A1, 2017], this invention has the advantage of using more accurate and reliable data acquisition technology, and realizing data acquisition and processing in a single computer, thereby avoiding the potential bottleneck of communications between platforms and its impact on the overall performance.
Italy, PCT