1. Cardiac Rhythm and Heart Failure, Medtronic, Inc., Mounds View, MN, 55112
2. Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada
3. Department of Biomedical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609
4. Assistant Professor Department of Biomedical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609 e-mail: