We present a spatial frequency domain imaging (SFDI) study of local hemodynamics in the forearm of healthy volunteers performing paced breathing. Real time Single Snapshot Multiple Frequency Demodulation - Spatial Frequency Domain Imaging (SSMD-SFDI) was used to map the optical properties of the subsurface of the forearm continuously. The oscillations of the concentrations of deoxy- and oxyhemoglobin at the subsurface of the forearm induced by paced breathing are found to be close to out-of-phase, attributed to the dominance of the blood flow modulation by paced breathing. The properties of local microcirculation including the blood transit times through capillaries and venules are extracted by fitting to Simplified Hemodynamics Model. Our preliminary results suggest that the real time SSMD-SFDI platform may serve as one effective imaging modality for microcirculation monitoring.
We present here the numeric study of the propagation of polarized coherent complex light in turbid media with Electric field Monte Carlo (EMC) approach. EMC is one unique Monte Carlo method suitable for simulating coherent phenomenon of multiple scattering light. EMC has been extended to explicitly incorporate the complex incident wave front of coherent complex light and used to investigate the interaction of coherent complex light with highly scattering turbid media such as biological tissue. We will report the dependence of the decay of the beam intensity and the loss of the polarization over the penetration depth on the orbital angular momentum of the complex light and the scattering properties of a turbid medium. The potential application of complex light in imaging turbid media will be discussed.