1School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, United States, 2School of Mechanical Engineering, Purdue University, West Lafayette, IN, United States, 3Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, MA, United States, 4Institute for Aging Research Instructor in Medicine, Harvard Medical School, Boston, MA, United States, 5Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, United States, 6Department of Basic Medical Sciences, Purdue University, West Lafayette, IN, United States, 7Department of Health and Kinesiology, Purdue University, West Lafayette, IN, United States