1. Department of Mechanical Engineering, Georgia Institute of Technology, Atlanta (I.D.M.-D.).
2. Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta (V.S., A.P.Y.).
3. Exponent, Inc, Philadelphia, PA (P.A.M.).
4. Emory University Hospital, Atlanta (V.B.).
5. Cedars-Sinai Heart Institute, Los Angeles, CA (R.S., R.M.).