1. Electrical and Information Engineering Department, University of the Witwatersrand, Johannesburg 2000, South Africa e-mail:
2. Department of Neurology, Rambam Healthcare Campus, Haifa 31096, Israel e-mail:
3. Modelling and Digital Science Unit, Council for Scientific and Industrial Research, Pretoria 0001, South Africa e-mail:
4. Mechanical Engineering Department, Massachusetts Institute of Technology, Cambridge, MA 02139 e-mail:
5. Department of Neurology, Tel-Aviv University Medical School, Tel-Aviv 69978, Israel e-mail: