1. Division of Biomedical Engineering, Department of Human Biology, University of Cape Town, Cape Town 7925, South Africa;
2. Department of Computer Engineering, Mbarara University of Science and Technology, Mbarara 1410, Uganda
3. Division of Biomedical Engineering, Department of Human Biology, University of Cape Town, Cape Town 7925, South Africa
4. Division of Biomedical Engineering, Department of Human Biology, University of Cape Town, Cape Town 7925, South Africa; Lodox Systems (Pty) Ltd, Johannesburg 2146, South Africa