1. School of Mechanical Engineering, Purdue University , West Lafayette, IN 47907
2. Department of Neurological Surgery, Indiana University School of Medicine , Indianapolis, IN 46202
3. School of Mechanical Engineering, Purdue University , West Lafayette, IN 47907 ; , West Lafayette, IN 47907
4. Weldon School of Biomedical Engineering, Purdue University , West Lafayette, IN 47907 ; , West Lafayette, IN 47907