1. Department of Biomedical Engineering & Orthopaedic Surgery/Campbell Clinic, University of Tennessee Health Science Center, Memphis, TN 38163, USA
2. Research Service 151, VA Medical Center, 1030 Jefferson Avenue, Memphis, TN 38104, USA
3. Department of Biomedical Engineering, Vanderbilt University, VU Station B 351631, Nashville, TN 37235-1631, USA