[1] Univ Calif Los Angeles, Dept Elect & Comp Engn, Los Angeles, CA 90032 USA
[2] Calif NanoSyst Inst, Los Angeles, CA USA
[3] Univ Calif Los Angeles, Dept Bioengn, Los Angeles, CA USA
[4] Univ Calif Los Angeles, David Geffen Sch Med, Dept Surg, Los Angeles, CA 90095 USA
[5] Loyola Marymount Univ, Dept Elect Engn & Comp Sci, Los Angeles, CA 90045 USA