1. Reid Heart Center/FirstHealth of Carolinas Cardiac and Vascular Institute, Pinehurst, NC, USA
2. Department of Physics, Naval Postgraduate School, Monterey, CA, USA
3. Particle Engineering Research Center, University of Florida, Gainesville, FL, USA
4. Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC, USA
5. Department of Bioengineering, Stanford University, Stanford, CA, USA.