1. GT-Bionics Lab, School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30308, USA.
2. Shepherd Center, Atlanta, GA 30309, USA.
3. Rehabilitation Institute of Chicago, Chicago, IL 60611, USA.
4. Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
5. Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
6. School of Medicine, Emory University, Atlanta, GA 30307, USA.