1. From the Biomedical Engineering Program, University of Houston, Houston, Texas; and the
2. Institute of Optics and Biophotonics, Saratov State University, Saratov, Russia.
3. From the Biomedical Engineering Program, University of Houston, Houston, Texas; and the2Institute of Optics and Biophotonics, Saratov State University, Saratov, Russia.