Multiplexed fibre-optic real-time monitoring of fluorophores in perfused hearts

We have developed a prototype multiplexed fiber-optic system that enables real-time monitoring of hypoxia-sensing fluorophores in beating isolated rat hearts, providing dynamic data useful for the assessment of cardiac metabolism, with potential for cross-correlation and biological validation using parallel MR spectroscopy and PET or SPECT imaging. The system has been designed to suppress background and increase light efficiency. We have established a data analysis pipeline using nonnegative least-squares curve fitting allowing unmixing of overlapped fluorescence spectra and fluorophore quantification. In this first phase of our work, we demonstrate simultaneous detection of a mixture of fluorophores in isolated perfused hearts.