1. Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 e-mail:
2. General Electric Global Research, Niskayuna, NY 12309 e-mail:
3. General Electric Healthcare, Waukesha, WI 53188 e-mail:
4. Professor Mem. ASME School of Engineering, Rutgers University, New Brunswick, NJ 08901 e-mail: