1. Research And Exploratory Development Department, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd., Laurel, MD, 20723 USA
2. School of Electrical & Computer Engineering, Georgia Institute of Technology, 777 Atlantic Dr. NW, Atlanta, GA, 30332 USA
3. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Dr., Atlanta, GA, 30332 USA
4. Department of Biomedical Engineering, University of Pennsylvania, 210 South 33rd St., Philadelphia, PA, 19104 USA