1. Wallace H. Coulter Department of Biomedical Engineering; Georgia Institute of Technology and Emory University; Technology Enterprise Park, Suite 200, 387 Technology Circle Atlanta 30313-2412 GA U.S.A.
2. Department of Mechanical Engineering; St. Martin's University; 5000 Abbey Way SE Lacey 98503 WA U.S.A.
3. Department of Mechanical Engineering; University of Maine; 219 Boardman Hall Orono 04469-5711 ME U.S.A.