  Optoacoustic (OA) imaging combined with reversibly photoswitchable proteins
has emerged as a promising technology for the high-sensitivity and multiplexed
imaging of cells in live tissues in preclinical research. Through
carefully-designed illumination schedules of ON and OFF laser pulses, the
resulting OA signal is a multiplex of different reporter species and the
background. By exploiting their distinct inherent photo-physical properties
which govern the rate of switching, one can recover the concentration maps of
protein reporters from the temporally entangled OA images. In this paper, we
propose a quantitative unmixing approach in the form of a regularized inversion
algorithm based on a mathematical model of the temporal decay of the signal
measuring the underlying protein reporters. We validate three types of
reporters on simulated and experimental datasets and show successful unmixing
results.
