1. Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118
2. Department of Electronics and Communications Engineering, BioMediTech, Tampere University of Technology, 33720 Tampere, Finland
3. Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110
4. Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425