1. Department of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229;
2. Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio, TX 78229
3. Department of Mechanical Engineering, University of Texas at San Antonio, San Antonio, TX 78249
4. Department of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229
5. Department of Epidemiology and Biostatistics, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229
6. Department of Anatomy, University of Environmental and Applied Sciences U.D.C.A., Bogotá, Cundinamarca, Colombia
7. Department of Anatomy, Faculty of Veterinary Medicine, University of the Republic, Montevideo 11200, Uruguay
8. Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio, TX 78229 e-mail:
9. Fellow ASME Department of Mechanical Engineering, University of Texas at San Antonio, San Antonio, TX 78249