1. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853
2. Meinig School of Biomedical Engineering, Cornell University, 113 Weill Hall, Ithaca, NY 14853;
3. Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853;
4. Research Division, Hospital for Special Surgery, New York, NY 10021 e-mail: