1. Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge , MA, USA
2. McCance Center for Brain Health, Massachusetts General Hospital , Boston, MA, USA
3. Division of Sleep Medicine, Harvard Medical School, Boston , MA, USA
4. Department of Neurology, Beth Israel Deaconess Medical Center, Boston , MA, USA
5. Emerald Innovations Inc., Cambridge , MA 02142, USA
6. Computer Science Department, University of Illinois Urbana-Champaign, Urbana , IL, USA